What is included in maintenance? Maintenance

Maintenance of equipment TO-1, TO-2, EO - these are regulations that determine the frequency and volume maintenance technological equipment.

Industrial equipment, like any other, needs timely maintenance, since only in this case can the uninterrupted operation of the enterprise be guaranteed. Forced downtime results in enormous costs. Timely maintenance can help you avoid such problems.

Maintenance Tasks
The maintenance procedure is performed at the intervals recommended by the manufacturer. In essence, it is a preventive measure designed to protect production site from downtime. Planned maintenance is carried out in accordance with the approved schedule and includes standard set operations repeated over and over again.

The Sintez TMK company recommends regularly taking care of the condition of the equipment and offers the following services:

• Regular inspection, constant monitoring of equipment performance, which can be carried out once a day, week, month;
• Scheduled maintenance provided for in the technical documentation for the equipment usually includes oil changes and consumables;
• Emergency maintenance caused by equipment failure.

Specialists take care of maintaining the equipment in good condition, carry out technical inspection, adjustment, and other required manipulations.

The workshop uses equipment for various purposes, differing in operating principle and design. To have a good understanding of equipment maintenance, you need to have knowledge about a specific machine, and it is difficult for the mechanic responsible for the work of the workshop to keep up with constantly updated equipment. In order not to maintain a large staff of narrowly focused craftsmen for servicing specific equipment, It’s easier to entrust its maintenance to a professional equipment company.

At Sintez TMK, employees keep up with the latest technology and are constantly trained to work with new equipment. People who are able to assemble a unit from scratch are well versed in its design and immediately notice problems in operation. Such specialists will ensure that the equipment is in good working order and will carry out routine or repair work in a timely manner.

All specialists have the necessary permits. A guarantee is provided for the work performed, and the price is significantly lower than paying an additional full-time employee. Even if the documentation for the equipment is lost, our specialists will be able to restore it.

Depending on the timing and scope of work, the Regulations provide for the following types and frequency of maintenance:

• Daily (shift) maintenance (EO) – once a day (shift);
• Maintenance 1 (TO-1) – for each type of equipment, usually once a month (includes EO);
• Maintenance 2 (TO-2) – for each type of equipment, usually after 6 months (includes EO, TO-1).

The main purpose of the EO is general visual inspection of the technical condition and appearance equipment and structures aimed at ensuring their trouble-free (failure-free) operation.

The main purpose of TO-1 and TO-2 is to reduce the wear rate of parts, identify faults and prevent failures through the timely replacement of some components products, carrying out inspection and diagnostic, lubrication, fastening, adjustment and other work, performed, as a rule, without disassembling the products and removing their individual components.

Maintenance of EO, TO-1 and TO-2 main structures and technological equipment is carried out by personnel of the fuel and lubricants service, with the exception of work that must be performed by other services in accordance with current documents.

Types of maintenance

You can order the following types of maintenance from us industrial equipment:

• Current. It includes inspection and monitoring of the operation of equipment with a specified regularity (every shift, daily, etc.);
• Planned. Performed in accordance with technical specifications and data sheets of specific industrial equipment. Examples of scheduled maintenance are: changing oil, filters, components, etc.
• Emergency. The need for it arises spontaneously when equipment breaks down. The reasons are often operational errors, hidden defects of individual components, parts, structures and other reasons.

The first two types of services can be provided on a planned basis, when both the customer and our specialists know in advance when, to what extent and what specific operations will be performed at the client’s enterprise.

Emergency maintenance cannot be planned and predicted, but you can submit an urgent request for emergency maintenance at any time, we guarantee the shortest turnaround time.

At Sintez TMK you can order maintenance for the following categories of industrial equipment:

– Black and non-ferrous metallurgy
– Mining industry
– Oil refining industry
– Oil industry
– Heavy and light engineering
– Chemical industry
– Petrochemical industry
– Oil and gas industry

Benefits of contacting us

When ordering service from Sintez TMK, our clients enjoy the following benefits:

• Experience of specialists in each area of ​​industrial production.
• If technical documentation for industrial equipment is lost, we will help you restore it and, if necessary, develop it again.
• All types of services are carried out under a contract with a guarantee.
• We guarantee real prices and offer mutually beneficial cooperation.
• All specialists have permission to work with industrial equipment, the company is a member of the SRO.

Maintenance(Maintenance) of vehicles, depending on the frequency and list of work, is divided into the following types:

• daily maintenance (DM)
• maintenance after running-in (TO-1000, TO-2000)
• first maintenance (TO-1)
• second maintenance (TO-2)
• seasonal maintenance (MS)

Changing the types of maintenance is allowed based on the recommendations of the service books of the vehicle manufacturers.

All types of vehicle maintenance must be performed according to the full list of works provided for by the relevant TYPE and TD.

Daily Maintenance (DM)

Daily Maintenance(EO) must ensure the release of a serviceable and clean vehicle in a condition that ensures its trouble-free and safe operation.

SW is carried out daily and includes:

• control work - monitoring the technical condition of parts, devices, assemblies and assemblies that ensure vehicle operability and safety traffic, fire safety, vehicle control in general
• cleaning and washing work (can be additionally performed at line dispatch stations or route terminals. In this case, the labor intensity must correspond to the actual volume of work performed)

Maintenance after break-in is carried out in accordance with the vehicle manufacturer's operating instructions.

TO-1 and TO-2

First maintenance(TO-1) and second maintenance(TO-2) are performed periodically, through the set in regulatory documentation mileage, and include a set of operations that prevent malfunctions, reduce the wear rate of vehicle parts, reduce consumption and reduce negative impact on the environment.

The frequency of TO-1 is set to a multiple of the frequency of TO-2. The actual frequency of vehicle maintenance may differ from the standard by no more than ± 15%.

The scope of maintenance work after running-in, TO-1 and TO-2 of vehicles includes:

• cleaning, washing and cleaning work
• technical diagnostics before performing maintenance
• inspection and control of the technical condition of parts, devices, units, assemblies, and vehicles in general
• control of fastening connections of parts, devices, components and assemblies
• adjustment of devices, components, assemblies and systems
• lubrication, oil change
• performing routine repair (TR) work of low labor intensity. To calculate its labor intensity, it is allowed to use no more than 20% of the adjusted labor intensity of the corresponding maintenance
• quality control of maintenance performance

Depending on the scope of work, TO-1 and TO-2 can be divided into the following types:

• every first maintenance (1 maintenance-1, 1 maintenance-2)
• every second maintenance (2 maintenance-1, 2 maintenance-2)
• etc.

Seasonal Maintenance (MS)

Seasonal Maintenance(CO) is performed twice a year during the transition to the spring-summer or autumn-winter periods of operation to prepare the vehicle for trouble-free operation in new conditions. Carrying out SB, as a rule, is combined with carrying out TO-2 with a corresponding increase in its planned labor intensity. Labor intensity standards for CO are 20% of the labor intensity of TO-2, for buses in preparation for autumn-winter operation - 30%.

The scope of work on vehicle maintenance includes work performed during scheduled maintenance-2, in addition, the following is additionally performed:

• checking the tightness of the engine cooling system, heating and ventilation of the cabin;
• replacing oils and lubricants with grades appropriate for the upcoming operating season
• disconnecting or connecting the heating system
• bringing the electrolyte density to the required parameters, charging batteries
• checking the tightness and insulation of the driver’s cabin (during the transition to the autumn-winter season)
• preparing pneumatic system devices for the upcoming operating season
• checking the condition of the fire extinguishing system
• checking the tightness and fastening of the modulators of the ABS (anti-lock braking) and ASR (anti-traction) systems
• preparation of the power supply system, cooling system, electrical equipment

Vehicle maintenance is carried out in accordance with the requirements of the manufacturers' technical documentation until standards are developed and approved in the prescribed manner.

Temporarily, until the development and approval of standards for the corresponding vehicle model, it is allowed to apply labor intensity standards for vehicle analogues.

The standards do not take into account labor costs for auxiliary work, which are set at no more than 30% of the total volume of work on vehicle maintenance and repair.

When developing technological processes for vehicle maintenance and repair, the labor intensity of the work must take into account allowances and be determined by the formula:

T = T„ * K
where T is the labor intensity of the work, man-hours
Т„ - labor intensity of the operation (calculated based on the results of time-lapse observations), person-hour
K - time spent on servicing the workplace, preparatory and final work, rest and personal needs, % of the labor intensity of the operation

Maintenance

Maintenance - this is the list of work performed in the intervals between planned and unscheduled equipment repairs, which allows us to ensure the required level of equipment reliability.

Proper maintenance and operation of industrial equipment can significantly reduce equipment repair costs and reduce downtime.

Mechanics often have questions: what list of work should be included in maintenance, who should perform it (operating personnel or support services), where to find a standard maintenance manual. I will try to answer these questions further.

Let me start with the fact that two GOSTs are considered the main documents regulating the use of a maintenance system: GOST 28.001-83 “System for maintenance and repair of equipment. Basic provisions” and GOST 18322-78 “System for maintenance and repair of equipment. Terms and definitions.” According to these documents, maintenance is divided by types and methods.

Types and methods of maintenance
What is it classified by?	Name of the term
Types of maintenance
Operation stages	Storage Maintenance
Moving Maintenance
Operational Maintenance
Maintenance while waiting
Frequency of execution	Periodic Maintenance
Seasonal Maintenance
terms of Use	Maintenance under special conditions
Regulation of implementation	Scheduled Maintenance
Maintenance with periodic inspection
Continuously monitored maintenance
Organization of execution	Inline Maintenance
Centralized maintenance
Decentralized maintenance
Maintenance by operating personnel
Maintenance by specialized personnel
Maintenance by the operator
Maintenance by a specialized organization
Maintenance by the manufacturer
Maintenance Methods
Organization of execution	In-line maintenance method
Centralized maintenance method
Decentralized maintenance method
Maintenance method by operating personnel
Maintenance method by specialized personnel
Operator's maintenance method
Method of maintenance by a specialized organization
Manufacturer's maintenance method

A painful issue for chief mechanics is who should perform equipment maintenance. On the one hand, it involves supervision and care of equipment, often without stopping it. On the other hand, it is included in the MRO or PPR system as planned routine work, as an intermediate set of measures between scheduled repairs.

A good solution is to divide the concept of maintenance into routine and planned.

Routine Maintenance(hourly, shift inspection and control, lubrication and other similar work) must be carried out production staff workshop or site. Firstly, it is rational from a personnel point of view (it does not require an increase in the repair service staff). Secondly, this approach is useful for purely methodological purposes - it allows operators working on equipment to become more deeply familiar with the device and operating principle.

Current or unscheduled maintenance includes:

· strict compliance with the equipment operation requirements specified in the technical operational documentation of the manufacturer;

· monitoring the operating mode of equipment to prevent overloads;

· temperature control;

· control of lubrication frequency at all points;

· instant shutdown and de-energization of equipment that has failed;

· visual inspection of wear of components and mechanisms;

Scheduled Maintenance

Scheduled maintenance and repairs(if necessary) is carried out by maintenance personnel. Planned work traditionally includes work that requires disassembly of any piece of equipment. Of course, such work must be performed by a trained repairman. staff.

Planned or regulated maintenance performed by repair personnel include:

· diagnostics and monitoring of equipment performance characteristics;

· adjustment and adjustment;

· cleaning working parts and other places prone to clogging;

· topping up and changing oil, replacing filters;

· identification of violations in the operation of equipment;

All results of changes in the condition of the equipment being maintained (both during routine and scheduled maintenance) must be recorded. To do this, various methods are used: they keep operational or repair logs, enter them into a computer, and use inspection cards.

The method of organizing maintenance and repair using technological maps maintenance. They make it possible not only to communicate to the maintenance personnel in an accessible form the list and frequency of maintenance work, but also to monitor the execution of these works. The effect can be enhanced by organizing work-around routes for repair personnel, drawing up specifications for consumables, and drawing up a lubricant map.

Typical maintenance manuals does not exist. The bulk of such documents have a local status and are developed within the framework of a management system. In addition, each type of equipment requires its own list repair work. In order to get rid of unnecessary paperwork, the equipment available at the enterprise is sorted into groups and maintenance methodologies are developed for them.

It is convenient to separate the equipment in two stages.

The first one is in accordance with balance sheet fixed assets:

· technological equipment;

· electrical engineering;

Most often, mechanics are interested in the “technological equipment” group, as it is the most numerous and requires constant attention.

It, in turn, is usually divided into subgroups according to purpose:

· metal-cutting equipment;

· woodworking equipment;

· foundry equipment;

Within these subgroups, it is much more convenient to select objects for description and implementation of repair functions over them.

Below, you can familiarize yourself with the scope of work that is usually included in maintenance for various groups of equipment:

· List of works during maintenance of metal-cutting machines;

· List of works during maintenance of woodworking machines;

· List of maintenance work forging and pressing equipment;

· List of works during maintenance of foundry equipment.

6 Types of planned work

Planned repairs, depending on the volume, complexity and timing of the work, are divided into current, medium and major repairs.

Current repairs provides for the replacement or restoration of individual parts without disassembling the machine, adjustment of mechanisms to ensure or restore the functionality of the unit before the next scheduled repair.

Medium renovation is carried out with partial disassembly of the machine, while replacing or restoring components of a limited range, restoring serviceability and partial service life of the equipment.

At major renovation complete disassembly of the unit, replacement or restoration of all worn parts and assemblies, including basic ones, assembly, adjustment and testing of the unit under load. A major overhaul should not only restore the original characteristics of the unit, but also improve them through modernization.

Modernization eliminates obsolescence of outdated equipment and provides for either an increase in the general technical level of the unit, or its adaptation (specialization) to perform individual work.

Equipment is taken out for major repairs depending on its technical condition, which is determined based on the results of technical diagnostics - assessing the wear of friction surfaces of individual equipment parts and the state of their interfaces during operation without disassembly.

4 PPR system is a set of planned organizational and technical measures for the care, supervision, maintenance and repair of equipment. The measures are preventive in nature, i.e. After each piece of equipment has worked for a certain amount of time, its preventive inspections and scheduled repairs are carried out: small, medium, major.

The alternation and frequency of repairs is determined by the purpose of the equipment, its design and repair features, as well as operating conditions. PPR equipment provides for the implementation next works:
- overhaul maintenance;
- periodic inspections;
- periodic scheduled repairs: small, medium, major.

Between overhauls- this is the daily care and supervision of equipment, carrying out adjustments and repairs during its operation without disrupting the production process. It is performed during breaks in the operation of equipment (during non-working shifts, at the junction of shifts, etc.) by the shop repair service personnel on duty.

Periodic inspections- inspections, washings, accuracy tests and other preventive operations carried out according to plan after a certain number of hours worked by the equipment.

Periodic scheduled repairs divided into small, medium and major repairs.

Small repairs- detailed inspection, change and replacement of worn parts, identifying parts that require replacement during the next scheduled repair (medium, major) and drawing up a defective list for it (repair), checking for accuracy, testing equipment.

Medium renovation- detailed inspection, disassembly of individual components, replacement of worn parts, checking for accuracy before disassembly and after repair.

Major renovation- complete disassembly of equipment and components, detailed inspection, washing, wiping, replacement and restoration of parts, checking for technological accuracy of processing, restoration of power, performance according to standards and specifications.

PPR is carried out according to a schedule developed on the basis of PPR standards:
- duration of the repair cycle;
- duration of overhaul and inspection cycles;
- duration of repairs;
- categories of repair complexity (RCC);
- labor and material intensity of repair work.

Repair cycle- this is the period of operation of the equipment from the beginning of its commissioning until the first overhaul, or the period of work between two major overhauls. The structure of the repair cycle is the order of alternating repairs and inspections, depending on the type of equipment, the degree of its load, age, design features and operating conditions.

Repair complexity category (RCC) assigned to each piece of equipment. As repair unit 1/11 of the labor intensity of a major overhaul of a 16K20 screw-cutting lathe, which belongs to the eleventh complexity group, was accepted.

Basic repair operations

During the repair process, the following basic operations are performed.

1. The machine or apparatus is disconnected from the communication network, the belts are removed, the engine shaft coupling half is disconnected, and the oil is drained from the reservoirs. If it is an apparatus, then it is freed from the medium that fills it, using drains to drain it by gravity, purged with steam or air, washed with water, etc. After this, the equipment is securely disconnected from the system by installing plugs on the flange connections before or after the shut-off valves. The plugs must have a clearly visible shank with a designated number.

2. Cleaning and washing of equipment.

3. Defects and sorting of parts.

4. Restoration or replacement of worn parts.

5. Balancing rotating parts (if necessary).

6. Assembling a machine or apparatus.

7. Individual testing and commissioning.

Before starting repairs, the equipment is thoroughly washed and cleaned of product residues, grease and other contaminants. Surfaces in contact with products are cleaned with brushes and brushes, washed with hot solutions of soda ash or caustic soda, hot water and treated with steam.

To clean equipment crankcases, they are washed with hot oil, furnace flue gas, kerosene and hot water. The use of kerosene and heating oil, which have a strong odor, in production workshops is not allowed in order to avoid defective products produced on machines and devices located close to the equipment being repaired.

Before disassembling the equipment, it is necessary to study the design features of the machine and outline the procedure for its disassembly. In this case, the purpose and interaction of individual components and parts should be established. First of all, those parts and assembly units that prevent further disassembly are removed. Equipment with a complex design is disassembled in the following order: first into groups of assembly units, groups into individual assembly units, assembly units into parts. The parts must be placed in the order in which they are removed from the machine.

Parts are cleaned of dirt and rust after disassembling the machine using wooden blades, rods and scrapers. In addition, the parts are soaked in kerosene, for which two containers are used: the first for preliminary soaking, the second for final rinsing. The duration of soaking the pre-cleaned parts is 1 – 8 hours, after which they are wiped dry with a rag. Parts are degreased in a hot solution of caustic soda, then washed in hot water and dry.

Lubrication grooves and holes in parts are blown out with compressed air.

Balancing of rotating parts (rotors) can be static or dynamic. Depending on the peripheral speed and the ratio of the width B of the rotating part to its diameter D, the balancing method is chosen according to the data in table. 3.1.

Table 3.1. Data for choosing a balancing method

When repairing gears and sprockets, the possibility of their continued suitability for use is determined.

The parts are assembled in the reverse order of disassembly. In this case, they are guided by the tolerances given in the manufacturer’s instructions and technical specifications for manufacturing, packaging and delivery. The procedure for conducting individual tests at idle speed and communications is carried out after completion of repair work.

3.4. Mechanization of repair work

When dismantling and assembling machines (units) in order to replace worn-out components or restore them, various lifting mechanisms are used: standard overhead cranes, truck cranes, loaders, self-erecting gantry cranes, rod lifts, hoists, lever winches, etc.

In mechanical repair shops, standard overhead cranes, trolleys, jib cranes, and roller tables are used to move large parts and assemblies from one metalworking machine to another.

Technical repair operations for boring and grinding compressor cylinder blocks are performed on appropriate machines, drilling holes - on radial drilling and vertical drilling machines, forming keyways - on planing and milling machines, cutting threads - on threading machines, etc. Elimination of cracks and breakages of the bed and frames, surfacing of worn shaft journals, etc. carried out using electric arc welding, for which mechanized welding methods are used.

When repairing equipment at the site of its installation, manual mechanized tools (electrified and pneumatic) with various devices are widely used: drilling machines, edge cutters, impact wrenches, grinders, electric rolling machines. In this case, devices are used for boring holes in the tube plates of heat exchangers, for deburring and trimming pipes, for crushing the ends of flared pipes to be removed and replaced, for grooving the seats of valve bodies and gate valves, for lapping pipeline fittings etc.

AND EQUIPMENT REPAIR

Types of wear

Wear refers to the gradual surface destruction of a material with a change in geometric shapes and properties surface layers details. Wear can be normal or emergency. Depending on the causes, wear of parts is divided into chemical and physical and wear by metal seizure (thermal wear).

Normal wear refers to changes in the dimensions and properties of materials of parts that occur under conditions of proper operation of the equipment. The intensity of normal wear is determined mainly by the design features of the components, the wear resistance of the materials used, as well as the correct operation and repair of the equipment.

Normal wear is inevitable, however, the intensity of its occurrence can be influenced by the quality of installation, operation and repair of equipment. With individual unfavorable conditions normal wear turns into abnormal wear.

Emergency wear is called changes in the dimensions and properties of the materials of parts that occurred in a relatively short term due to improper installation, operation, unsatisfactory maintenance or poor quality repair of equipment.

Chemical wear of the friction surface consists mainly of the formation and subsequent peeling of thin oxide films on them. Oxide films are formed as a result of chemical absorption (chemisorption) of oxygen coming from the air or resulting from the breakdown of lubricant components by the surface layers of the metal. The destruction that occurs as a result of chemical wear is accompanied by the appearance of smallpox-like ulcers, corrosion of the metal or the appearance of rust.

As a result of physical wear, which can be caused by alternating loads, surface friction, abrasive and mechanical effects, microcracks appear on the parts, and the surface of the parts becomes rough. The main types of physical wear are fatigue, wear, abrasion and erosion.

Fatigue wear is observed in parts subjected to repeated action of alternating and varying single-valued loads, as a result of which microcracks are formed, and then complete destruction (breakage) of the part occurs.

Small-scale wear occurs during dry and especially liquid rolling friction and is characterized by the formation of cracks on periodically loaded surfaces, followed by peeling of films from 0.005 to 0.2 mm. Parts of rolling bearings and working surfaces of gear teeth are subject to wear-like wear (Fig. 4.1).

Rice. 4.1. Scheme of smallpox wear: a – diagram of tangential stresses that arise when a cylinder or ball is pressed into a flat surface; b – diagram

crack formation

Abrasive wear is the destruction of the surface of parts by tiny particles more than hard materials. In machines, metal particles, lubricant oxidation products, mineral particles (sand, shavings, etc.) coming from outside can be abrasive. The surfaces of all friction units are subject to abrasive wear.

Erosion - mechanical destruction (erosion, corrosion) of the surface layers of materials of parts moving at high speed, by particles of the gaseous, liquid or solid phase - occurs together with intense oxidative processes.

Wear by metal seizure is characterized by the emergence and subsequent destruction of molecular bonds on the friction surface (change in grain structure, decrease in hardness, melting, tempering, etc.).

Conditions for the emergence of connections are caused by both relatively low and high temperatures contact areas. This type of wear is observed in various parts of steam boilers, engines, compressors and refrigeration machines.

4.2. The main reasons affecting the wear of equipment parts

The nature and amount of wear is influenced by many design and operational factors. This must be taken into account when manufacturing and restoring repaired parts.

Quality of parts material. The quality of the material of the parts and its heat treatment have great influence on their strength and wear resistance. As a rule, for most materials, the harder they are, the greater their wear resistance. work surface. But we cannot assume that the degree of hardness of a material is always directly proportional to wear resistance.

Materials that only have high hardness have high wear resistance, however, this increases the possibility of scratches and tearing of material particles from the surface. Therefore, these materials must have high viscosity, which prevents particles from detaching.

If parts made of homogeneous materials experience mutual friction, then due to the high friction coefficient they quickly wear out. Consequently, more expensive and difficult to replace parts must be made from a harder, higher quality and wear-resistant material, while simpler and cheaper parts are better made from a relatively soft material with a low friction coefficient.

The correct choice of material for parts is of great importance both from the point of view of saving material and for preventing accidents during operation.

At enterprises food industry The most common metals used in equipment repair are ferrous (steel, cast iron) and non-ferrous metals, their alloys and plastics.

Quality of surface treatment of parts. The wear and service life of rubbing surfaces is greatly influenced by the quality of the surface after machining - surface cleanliness. Three wear periods have been established, which are shown on the parts wear curve (Fig. 4.2):

1) the initial period of running-in (section of curve 1–2) is characterized by a rapid increase in the gap in the moving joints;

2) the period of steady wear (section 2–3), after the running-in of the working surfaces, during this period, which is the main period, gradual and slow wear is observed;

3) a period of rapid increase in wear caused by significant changes in the gaps between rubbing surfaces and changes in the geometric shape of parts; from this moment, increased and catastrophically increasing wear begins, which can lead to an accident.

Rice. 4.2. Part wear curve diagram

To increase the service life of equipment parts, the running-in period should be reduced to the shortest possible time, the period of steady wear should be sharply increased and the period of increasing wear should be prevented. Reducing the running-in period is achieved by precise and clean processing of the surfaces of rubbing parts.

The state of surface cleanliness is measured by special instruments - profilometers and profilographs.

Lubrication. A layer of lubricant introduced between the rubbing surfaces increases the wear resistance of the contacting parts: the lubricant, getting between two rubbing surfaces moving one over the other, fills their unevenness and eliminates their direct contact, reduces friction, wear, the risk of jamming, heating and corrosion (Fig. 4.3).

Rice. 4.3. Diagram of pressure distribution in the oil layer:

O – bearing axis; O1 – shaft axis

The following types of sliding friction are distinguished:

1) dry friction, which occurs in the absence of lubrication on the rubbing surfaces;

2) semi-liquid and semi-dry, observed when the oil film is partially torn or when the lubricant layer is constantly thin, so that the irregularities of the rubbing surfaces partially touch. Semi-fluid and semi-dry friction occurs on insufficiently or improperly lubricated surfaces when used lubricant, not meeting the working conditions;

3) fluid friction, which occurs in cases where moving surfaces are completely separated by a layer of lubricant.

The process of creating a stressed oil layer during the operation of a shaft-bearing pair occurs as follows. There is a gap between the shaft and the bearing, starting from the point of contact of the shaft in the liner and diverging in both directions in the form of a wedge-shaped gap. The shaft is located eccentrically relative to the bearing.

When rotating, the shaft carries a layer of lubricant into the wedge-shaped gap. As this gap decreases, the resistance to the flowing lubricant increases more and more, reaching its greatest value in the narrowest part of the wedge-shaped gap. Due to this, the rotating shaft is raised, the bearing and the shaft are completely separated by a layer (film) of lubricant, the thickness of which will be the smallest. The wear of mating surfaces is minimal.

To ensure long-term operation of parts, the correct choice of lubricant and its reliable supply to the rubbing surfaces, as well as the correct lubrication regime for the working surfaces are necessary. If lubrication is improper, parts heat up excessively, rubbing surfaces seize and melt, which leads to equipment failure.

Speed ​​of movement of parts and specific pressure. Any equipment in operation is characterized by performance (performance, speed of moving parts, efficiency, etc.) and durability - the duration of operation of the equipment, during which its performance remains within acceptable limits.

Based on experimental data, it has been established that at normal specific loads and movement speeds from 0.05 to 0.1 m/s, the oil layer does not rupture and lubrication becomes complete. Wear of parts increases with increasing speed of relative movement of rubbing parts, as the temperature of the contacting surfaces increases, which can lead to crushing and melting. For example, for bearings with Babbitt filling, the temperature should not exceed 60 °C from the limit.

Violation of rigidity in fixed joints. In these cases, the tightness in the joints is broken (leaks), dynamic loads arise in the joints, and the tension in the connections sharply increases. To prevent violation of the rigidity of connections, it is necessary to systematically check the rigidity of fastening parts and restore it by tightening, avoiding work with loosening.

Landing violation. This group of faults is characterized by an increase in the gap in movable joints and a decrease in tension in fixed joints. To prevent this, you need to properly adjust the gaps and use special coatings on the surfaces of the moving joints.

Violation of the mutual position of parts in connections. Often there is a violation of components and parts in the kinematic chain, which leads to a deviation in alignment, a change in the distance between parts, and a violation of the perpendicularity of the axes of components and parts. To avoid this type of violation, you should systematically check the relative positions of parts and assemblies, adjust their positions, and, if necessary, restore their correct location.

Flaw detection of parts

To determine the condition of parts, external inspection is used, as well as methods that make it possible to detect hidden defects (magnetic and ultrasonic flaw detection and fluoroscopy). External inspection allows you to identify defects in parts: external cracks, bends, scuffing, wear of the anti-friction layer, thread failure, corrosion, etc.

The inspection ends with measurements using measuring instruments.

Deviations in the geometric shape of cylindrical parts are characterized by non-roundness (ovality, faceting) and deviations in the longitudinal section profile (cone-shaped, barrel-shaped, saddle-shaped).

Small cracks are detected by color flaw detection, the essence of which is as follows. On the surface of the part, cleaned with acetone or gasoline, 3-4 layers of a penetrating solution tinted with aniline dye are applied with a brush or spray. Then the controlled part is washed with a 5% soda ash solution and wiped dry. A thin layer of white adsorbent coating is applied to the cleaned surface with a brush or spray (for example, 0.6 liters of water + 0.4 liters of ethyl alcohol + 300-500 g of chalk).

Liquid from surface defects turns the coating red in the corresponding places.

The method allows you to detect defects up to 0.01 mm in size at a depth of 0.03-0.04 mm, inspection is carried out with the naked eye or using a magnifying glass of 5-7 times magnification.

The luminescent flaw detection method allows you to identify surface defects with a depth of at least 0.02 mm and a width of at least 0.01 mm.

The sequence of operations for fluorescent flaw detection is as follows:

1) cleaning the surface from contamination

2) application of a penetrating luminescent composition;

3) applying developing powder;

4) inspection of the part under ultraviolet rays.

The disadvantage of this method is the need to use a stationary flaw detector.

In cases where there are suspicions about the presence of open defects (defects), a magnetic, ultrasonic or x-ray inspection method is recommended.

Magnetic powder flaw detection is based on identifying the magnetic stray field above the defect.

A necessary condition To identify a defect, the location of the defect is perpendicular to the direction of the magnetic field. Therefore, the part must be checked in two mutually perpendicular directions.

X-ray inspection methods require an approach to the part from two sides. An X-ray machine is connected on one side, and a film cassette on the other side. This is not always possible due to design features devices.

The most widely used in repair practice are ultrasonic flaw detectors, which allow:

1. identify defects welds any kind;

2. identify internal defects (sinks, delamination);

3. measure the thickness of the walls of apparatus and pipelines with one-way access to them.

Ultrasonic flaw detectors allow you to determine the size and depth of defects. Minimum size detectable defect – 1mm². The thickness of the controlled parts is 1-2000 mm.

Ultrasonic flaw detectors are small in size and light in weight, but they are not applicable for testing stainless steel parts. The coarse-grain structure of stainless and alloy steels means that reflected pulses from large grains create interference, which makes it difficult to determine the reflection of a pulse from a defect.

To inspect stainless steel parts, color flaw detection, X-ray and gamma examination are used.

When inspecting pressure apparatus, it is necessary to inspect all welds. Some high-pressure equipment is subjected to inspection that combines 2-3 flaw detection methods.

If access to the weld is possible only from the outside or only from the inside of the apparatus, the density test is carried out by vacuuming the welds.

The weld seam is wetted with a soap solution. A box with a sponge rubber seal around its entire perimeter is placed on the area to be examined. The box is connected to a vacuum pump. Availability soap bubbles observed through the inspection window indicates welding defects.

Thermal or halogen leak detectors can be used to detect gas leaks.

The operation of thermal resistor leak detectors is based on measuring the difference in thermal conductivity of gases. The gas passes near the heat source, which is one of the arms of the bridge. The second arm is a sensor placed in the air.

Thermal resistor leak detector allows you to detect leaks (2-4)∙10ˉ6m³/h.

The halogen leak detector allows you to detect halogen leaks by changing the color of the halogen flame in refrigeration units.

All of the methods discussed above are non-destructive testing methods. However, if we are faced with the phenomenon of intergranular corrosion, then it can be detected using metallographic analysis of the structure of a sample cut from the wall of the apparatus.

Separator repair

The high accuracy class of the separators, the specificity of the materials from which the parts are made, the complexity of manufacturing and restoring these parts in the conditions of the enterprise’s mechanical repair workshops necessitate periodic inspections of the separators, timely detection of unacceptable wear and replacement of worn parts.

When repairing separators, the greatest specific gravity falls on the drive mechanism parts. Their wear is characterized by extraneous noise, increased vibration, slow acceleration of the drum and a number of other signs.

For inspection, the separator is disassembled, separately the horizontal shaft group and the spindle group. It is not recommended to disassemble the separator unless absolutely necessary, as this can lead to disruption of the fit and running-in of the mating parts. The separator is disassembled carefully, strictly following the procedure outlined in the factory instructions. After disassembly, all critical rotating parts are thoroughly washed, carefully inspected and measured. The most critical parts (spindle, plate holder, plates, especially spacers, bearings, etc.) are examined with a magnifying glass, and if a crack is suspected, X-ray and ultrasonic flaw detection tools are used.

When repairing separators, it is most often necessary to replace worn friction linings on the pads of the centrifugal friction clutch, springs and throat support bearings, thrust bearings, bronze gear (worm wheel), rubber sealing rings, rubber disc of the elastic coupling, etc.

The sequence of disassembling separators of different models has its own characteristics, which are indicated in the manufacturer's instructions.

10.08.2018, 12:24 180187 0 Assembly of Motorists

All drivers are well aware that vehicle maintenance is part of its operation. However, there is still a category of car owners who believe that no one needs a scheduled vehicle inspection with the replacement of spare parts recommended by the manufacturer and that it is simply a waste of money.

Is this really true? What is scheduled maintenance? What is it like? What does it include and how often should it be done for different car brands? Is it necessary to do this at all? Experts answer questions, express their opinions and give advice.

So. Why carry out routine maintenance?

First of all, you need to understand that car maintenance itself is a preventive measure that is aimed at preventing possible problems in the early stages. Those who believe that waiting for a part to fail and then replacing it will be more economical than undergoing scheduled maintenance are deeply mistaken. Any car service center will confirm that car repairs are much more expensive. And even if there is new car world brand, the laws of physics work on its units in the same way as on cars with high mileage, so even a small error in operation or a malfunction identified during diagnostics allows you to avoid serious breakdowns or even accidents.

Moreover, unlike cars of previous generations, a modern car is a complex of complex units controlled by electronics, so it cannot be done without computer diagnostics and other measures.

Types of scheduled maintenance and what does it include?

The frequency of replacement of various materials and parts of a specific car brand is indicated in the manual for it. Knowing these recommendations from the manufacturer and taking into account the mileage of a particular car, determine the frequency of scheduled maintenance of the car. In this case, the following types of maintenance are carried out for all machines.

EO– daily inspection, which includes mandatory activities before each departure.

At the same time, the driver himself checks the general condition of the car, the position and possible adjustment of the mirrors, the operation of sensors, headlights, other electrical equipment, checking the steering system, brakes, the condition of the body - in a word, inspecting the car and those activities that can be performed independently.

– maintenance, which should be carried out depending on the requirements of the car manufacturer every 10, 15 or 20 thousand km.

Typically TO 1 includes the following types of work:

– replacing the air filter;

– oil change;

– checking the battery charge;

– inspection of spark plugs;

– lubrication of hinges;

– checking tires with balancing and inflation if necessary;

– checking the level of technical fluids and topping up if necessary;

– diagnostics of chassis and brake systems, electrical equipment and other car systems with elimination of identified errors and malfunctions.

TO 2– maintenance carried out every 30 thousand km. Its goals and objectives are the same as in TO 1, but with a larger volume of work and its higher complexity.

For example, during maintenance 2, the fuel filter and cabin filter are changed, the brake fluid and coolant are changed. During Maintenance 2, the timing belt and other work can be replaced.

CO– seasonal maintenance. Obviously, this type of maintenance is carried out 2 times a year and includes measures to prepare the car for changing weather conditions, such as changing seasonal oil, tires, checking the interior heater, air conditioning, etc.

Below are examples of scheduled maintenance regulations for some car brands. Each regulation is a document indicating a list of activities and the frequency of their implementation.

Scheduled maintenance of KIA Sportage III

There are similar regulations for scheduled maintenance for Nissan, Mercedes, and Mazda. In a word, there are work schedules for periodic maintenance of absolutely all brands of manufactured machines.

How much does maintenance cost and can you save money on it?

Obviously, a technically trained car owner can carry out some types of work independently. In this case, a maintenance schedule must still be drawn up and if necessary, for example, computer diagnostics of systems or other complex activities, you should contact a car service center.

All this is true for cars with high mileage. But if it is necessary to maintain the warranty of a showroom car, you cannot do without contacting authorized auto centers and undergoing maintenance there with the appropriate marks in the service books. You can save money only if the service allows you to undergo maintenance with its consumables.

In addition, you need to understand that prices for maintenance in authorized car services, even within the same official dealer may vary greatly. This also applies to the materials they use. Practice shows that if you are not lazy, call different services and compare prices, you can save up to 20% on work and up to 50% on materials.

The conclusion is simple. Scheduled maintenance is necessary, you can try to save money on them, but you absolutely cannot risk your car and ignore them!

1.1. Enterprise equipment maintenance and repair system

Under MRO system means a set of interrelated tools, documentation and performers necessary to maintain and restore the quality of products included in this system.

As goals The maintenance and repair systems are defined as follows:

• maintaining equipment in working condition throughout its entire service life;
• ensuring reliable operation of equipment;
• ensuring productivity and quality of products;
• compliance with labor safety and environmental protection requirements.

The organization of the enterprise's maintenance and repair system is carried out on the basis of making (explicitly or in accordance with established practice) decisions on the following fundamental issues ():

• choosing a strategy for equipment maintenance and repair;
• determining the method of organizing repair maintenance of production;
• development of criteria for assessing the effectiveness of repair maintenance of production.

Figure 1.1 – Fundamental issues when organizing a maintenance and repair system

1.2. Equipment maintenance and repair strategies

Under MRO strategy implies a generalizing model of actions necessary to achieve set goals through the coordination and distribution of appropriate enterprise resources. Essentially, an MRO strategy is a set of rules for making decisions that guide the repair service (RS) of an enterprise in its activities to ensure the operability of equipment.

Brief description The main MRO strategies are given in.

Table 1.1 – Brief description of the main maintenance strategies

Information support model	Nature of the activities carried out
	REACTIVE	PREVENTIVE
STOCHASTIC MODEL (based on probabilistic, statistical indicators)	I. Operation to failure:* maximum use of equipment resource; + minimum costs for the content of the RS; – failures and costs of eliminating accidents are high and unpredictable.	II. Scheduled preventive maintenance (PPR):* fixed probability of emergency failures; + the best conditions for planning maintenance and repair; – significant costs for maintenance and repair due to the replacement of functional units and parts.
DETERMINISTIC MODEL (based on information about the actual technical condition (TC) of the equipment)	III. By TS:* information support decision-making process on maintenance and repair; + close to full use of equipment resource; – low efficiency in long-term resource planning;	IV. Proactive:* active proactive impact on the equipment's vehicle; + increasing the service life of equipment; + rational choice of time, types and volumes of maintenance and repair;
	+ minimal probability of emergency failures; – high demands to work culture and personnel qualifications.

Under reactive This implies maintenance and repair strategies, the need for repair actions in which is determined by the occurrence of some critical event within the framework of this strategy (failure, reaching the limit values ​​of regulated parameters). Preventive MRO strategies are aimed at preventing the occurrence of a critical event and are characterized by the possibility of carrying out preliminary planning and preparation of MRO (ordering repair crews, logistics) as opposed to reactive strategies, when the need to carry out MRO, and, accordingly, ensuring their preparation, before the onset of a critical event unpredictable.

Historically, the first (as the least demanding in terms of the level of organization and work culture) was formed run-to-failure strategy, which involves carrying out maintenance and repair operations on equipment to reach a critical state, which, as a rule, is characterized by the inability to perform specified functions, that is, loss of performance. The main advantages of this MRO strategy include the longest time between repairs, corresponding to the service life of the equipment, and the minimum costs of maintaining a repair service, the dominant function of which in this case is restoring the functionality of the equipment after it fails. On the other hand, the lack of ability to plan resources (financial, time, labor force and others) necessary to perform maintenance and repair, leads to a significant increase in the duration of the latter and to increased costs for eliminating accidents, including loss of production. Creating inventories of inventory items, as a rule, is not a satisfactory solution, since it entails a decrease in the liquidity of the enterprise. The volume of such reserves in a number of cases (especially in industries where unique single equipment is used) exceeds economically justified limits. Despite these shortcomings, in the case of inexpensively redundant and standard equipment, the failure of which does not have a critical impact on the technological process and does not pose a danger to environment, health and human life, this strategy is successfully used to this day.

In the first half of the twentieth century, with the increase in serial production and increased productivity of industrial enterprises, losses due to equipment failures became critical. The operating-to-failure strategy has been replaced by PPR strategy or repairs according to regulations, implying preventive maintenance and repair based on statistical information about the service life of equipment. Reducing the number of emergency failures is one of the main advantages of this strategy, although the likelihood of their occurrence is not completely excluded, but is fixed within specified limits. The PPR strategy provides best conditions for resource planning, “however, the main disadvantage of PPR outweighs all its advantages; it consists in carrying out repairs of actually serviceable equipment, as well as forced replacement of parts regardless of their residual life (in complex equipment, the difference in the resources of individual parts can reach 500%). All this leads to an unjustified increase in operating costs. The disadvantages of PPR also include a decrease in the residual life of equipment and an increase in the likelihood of failure when commissioning after repair.” This strategy ensured the best integration within the framework of a planned economy and made it possible to eliminate a number of shortcomings of the historically established exploitation to failure strategy. More complete use of equipment resource was achieved by reducing the likelihood of damage to parts with a potentially long service life , which could occur when elements that determine the service life of the equipment as a whole fail when operated to failure. Currently, the PPR strategy continues to be used in many enterprises, primarily for critical equipment and equipment, the failure of which can pose a danger to the environment, health and human life. In other cases, the PPR strategy is often applied only declaratively, which is due to increased requirements for the efficiency of the enterprise's maintenance and repair system in a market economy.

At the border of the 70-80s of the twentieth century, mobile and portable vibration measuring equipment was used in the repair maintenance of production, allowing vibration monitoring of equipment based on frequency analysis. At the same time, there was an accelerated development of reliability theory and research in the field of equipment performance properties. All this predetermined the emergence of a new scientific and applied field of knowledge - technical diagnostics, the achievements of which were used as the basis for the implementation of the MRO strategy according to TS. First of all, the vehicle maintenance and repair strategy is aimed at eliminating the shortcomings of the historically preceding maintenance strategy, namely, reducing the number of unreasonable repair actions in order to maximize the use of equipment resources. When applying this strategy, by monitoring the vehicle, the probability of emergency equipment failures is reduced to a possible minimum. The motto of this strategy is: “Equipment must be stopped for repairs moments before expected failure.”. Reducing the cost of equipment maintenance and repair, minimizing the number of unplanned failures, reducing the number of planned downtime caused by installation and assembly operations are undeniable advantages that accompany the implementation of a vehicle maintenance and repair strategy. The vehicle maintenance and repair strategy has put forward new requirements for the level of work culture. Within the framework of repair services and regulatory bodies, technical diagnostic units are allocated, and the importance of personal professionalism, qualifications and experience of workers, managers and specialists increases. On the other hand, since the regulation of maintenance and repair is determined by a stochastic factor - the actual technical condition of the equipment - the efficiency decreases long-term planning resources (the estimated period for preventing failures, and therefore planning for maintenance and repair in the case of using technical diagnostic tools, mainly does not exceed two to three months).

In order to ensure high performance indicators of equipment of industrial enterprises in lately All great popularity acquires proactive strategy MRO. The analysis carried out in the work allows us to determine a proactive maintenance and repair strategy as the most effective and appropriate for implementation in modern economic conditions. A proactive strategy combines the advantages of preventive repair actions of the preventive maintenance system and information support for the decision-making process, characteristic of maintenance and repair of technical equipment.

1.3. Proactive strategy for equipment maintenance and repairs

Essence A proactive strategy for equipment maintenance and repair is to carry out the necessary repair actions aimed at reducing the rate of development or eliminating faults that are identified on the basis of information about the actual technical condition of the equipment.

Theoretical foundations proactive equipment maintenance strategy postulates that initially all types of faults are present in rudimentary or obvious form in all machines put into operation. Various factors accompanying operation (design and non-design loads, the impact of environmental factors and nearby equipment, operating conditions, maintenance and repair, etc.), to one degree or another lead to the development various types malfunctions. The determining influence of a combination of factors causes the accelerated development of one or more faults, which become decisive in relation to the performance of the machine. By choosing repair actions in such a way as to reduce the influence of determining factors, it is possible to reduce the rate of development of faults, maintaining the operating condition of the machine. Rational choice and high-quality implementation these and only these repair actions is the task of the RS.

The proactive MRO strategy () is based on assessment of vehicle equipment, which can be carried out using the following methods:

• monitoring technological parameters;
• visual inspection;
• temperature control;
• acoustic and vibration diagnostics;
• examination using methods non-destructive testing(magnetic, electrical, eddy current, radio wave, thermal, optical, radiation, ultrasonic, control by penetrating substances).

Figure 1.2 – Repair maintenance of equipment as part of a proactive MRO strategy

Grounds for acceptance decisions on the need to carry out repair actions is a situation when the TC of one element (part, assembly, mechanism) of equipment leads to a deterioration in the TC of adjacent (spatially and/or functionally) elements.

List of possible repair effects:

• equipment care (cleaning, cleaning, anti-corrosion treatment);
• adjustment, tuning, adjustment (centering, balancing);
• ensuring connections (restoring the integrity of welds, tightening threaded connections);
• lubrication of friction surfaces;
• replacement of wearing parts;
• restoration or replacement of basic parts, including body parts.

Repair actions are carried out within the framework of the following groups of activities for equipment maintenance and repair:

1. Preventative Maintenance– a set of measures carried out periodically, which are aimed at preventing or reducing the rate of development of defects by ensuring design conditions for the interaction of equipment components (cleaning from process waste, wear products, corrosion, sediment, deposits, etc.; removal of dust, dirt, oil, slag, scale spills of raw materials, garbage and others; refilling, refilling of working fluids, refilling, replacement of consumables; replacement or restoration of replacement equipment and others).
2. Corrective Maintenance– a set of measures carried out as necessary, which are aimed at preventing or reducing the rate of development of defects by ensuring design conditions for the interaction of equipment units (adjustment and adjustment of equipment, including alignment, balancing; restoring connections of parts, ensuring the integrity of metal structures and pipelines; restoration of coatings, colors and others).
3. Predictive Maintenance– a set of measures aimed at establishing the actual TC of equipment in order to predict its changes during further operation and identify the most appropriate moment of application and the required types of repair actions (measurement of technical and technological parameters, sampling; monitoring, testing, checking equipment operating modes; control TC equipment, including technical diagnostic methods; non-destructive testing methods; technical inspection of equipment, inspection, inspection, audit and others).
4. Current repairs– a set of measures aimed at ensuring the operability of equipment by replacing or restoring its individual components that are not basic, except for replacement equipment.
5. Major renovation– a set of measures aimed at ensuring the operability of equipment by replacing or restoring its basic components and parts.

Choosing a proactive MRO strategy allows to provide:

• increasing the service life of equipment by reducing the rate of development or eliminating incipient faults at the initial stage of their occurrence;
• exclusion of secondary damage to equipment elements caused by failure of adjacent (spatially and/or functionally) elements;
• justification and implementation of only necessary repair actions, which reduces costs and load on the system, and also reduces the likelihood of failures caused by installation errors and interference in the functioning of operable equipment;
• reduction of costs for repair maintenance of production, due to a change in the structure of maintenance and repair in favor of increasing the number of inexpensive preventive actions instead of costly repair operations (replacement, restoration);
• rational choice of time, types and volumes of maintenance and repair due to early warning of malfunctions when using methods and means of technical diagnostics and non-destructive testing;
• reducing the likelihood of emergency failures caused by unsatisfactory technical equipment;
• increasing the equipment availability factor, which makes it possible to increase production volumes and reduce production costs;
• building consumer confidence in the manufacturer through timely fulfillment of contractual obligations and improving product quality as complex result improving work culture.

1.4. Methods for organizing repair maintenance of production

Method of organization repair maintenance of production determines the structure of the enterprise's RS, which has a direct impact on the efficiency of the MRO system as a whole.

Classic methods RS organizations are characterized by a range of forms from decentralized to centralized, which differ in the degree of concentration of management of forces and resources within a single specialized structure at the enterprise ().

Figure 1.3 – Classic methods of organizing repair maintenance of production

A method of organizing repair service, characterized by the distribution of RS forces and assets between production units enterprise is called decentralized.

Centralized the organization of a RS implies the presence of a specialized structure within the enterprise, which is entrusted with the entire scope of functions for the maintenance and repair of equipment of production and auxiliary divisions, and also bears full responsibility for ensuring the operability of the equipment.

The method of constructing a RS based on a wide range of intermediate forms, distinguished by varying degrees of centralization, is called mixed.

The most common forms of RS organization at domestic enterprises are mixed, while foreign practice indicates the high efficiency of centralized forms of equipment maintenance and repair, including the construction of a maintenance and repair system based on alternative methods of organizing RS.

Alternative methods Organizations of repair maintenance of production () imply the attraction of external resources (forces and means) to provide and perform maintenance and repair of the enterprise’s equipment. Depending on the degree of resource use external enterprises and transferring to them the corresponding responsibility for ensuring the operability of the equipment distinguish contracting And service methods of performing maintenance and repair work.

Figure 1.4 – Alternative ways to organize repair maintenance of production

To ensure the required level of effectiveness of the equipment maintenance and repair system, the joint use of classical and alternative methods of organizing repair maintenance of production at the enterprise is widespread.

1.5. Criteria for assessing the effectiveness of production repair maintenance

Performance assessment repair maintenance of production is carried out on the basis of criteria adopted at the enterprise. An effective system of criteria makes it possible to analyze not only the actual effectiveness of the existing MRO system, but also to quickly identify its shortcomings and determine ways for further improvement and development.

There are technical and economic approaches to assessing the effectiveness of an enterprise's DC. Technical approaches are distinguished by their primary focus on assessing criteria characterizing the performance of equipment, the possibility of using it to implement a given technological process. Economic approaches allow you to assess the effectiveness of the RS by comparing the costs of maintenance and repair and production losses caused by the technical equipment of the equipment.

Currently, the question of generalized technical and economic assessing the effectiveness of repair maintenance of production, which would allow performing comprehensive analysis effectiveness of the equipment maintenance and repair system should be classified as insufficiently developed, which leaves room for enterprises to develop their own approaches to solving it. This was, for example, undertaken in the works [,].

It is necessary to pay special attention to a common mistake. To assess the effectiveness of the MRO system, it is unacceptable to use criteria characterizing the activities carried out by the RS (volume of work performed: in quantitative, time, natural, cost and other similar indicators). The intensity of repair work often does not indicate the achievement of the main goal of repair maintenance of production - ensuring the operability of equipment. Evaluation of the effectiveness of the system should be based on external, and not internal indicators her work.

Only an effective methodology for assessing the effectiveness of production repair maintenance allows us to perform a high-quality analysis of the MRO system, the effectiveness of the RS activities, and ensure information support decision making process.

1.6. Accident rate

Accidents of industrial equipment lead to interruption of the technological process, which is accompanied by inevitable material losses, and can also cause man-made disasters and loss of life. Ensuring the operability of equipment with the transition from eliminating the consequences of accidents to preventing their causes is the main task of the enterprise's RS.

To assess the accident rate of equipment, operational (total downtime) or economic (production losses, cost of accident elimination) indicators can be selected. In this case, in the general case, it is advisable for an enterprise to evaluate not absolute values, but rather the dynamics of changes in selected parameters over time.

On the other hand, it may be of interest comparative analysis weighted accident rate indicators (suppose the amount of production losses and the cost of accident elimination for a certain reference period, related to the amount of costs for equipment maintenance and repair) of industry enterprises to identify the most effective forms of organization and methods for improving the RS.

Assessment of accident rates can be successfully used as an indicator of the effectiveness of RS reform measures, to evaluate the implemented technical and organizational solutions. Based on a comparison of economic losses from accidents and funds allocated to finance RS, their optimal volumes can be established. The same is true for estimating the number of maintenance personnel.

Regulations and systems governing the investigation of accidents at industrial enterprises, as a rule, are developed on the basis of the “Procedure for the investigation and recording of accidents, occupational diseases and accidents at work,” approved by Resolution of the Cabinet of Ministers of Ukraine No. 1112 of August 25, 2004. However, it often remains unresolved main task. We are talking about the full and effective use of information obtained during the investigation, and not so much for elimination, but for preventing subsequent accidents on the same or similar equipment.

An accident investigation involves a step-by-step solution to the following sequence of tasks:

1. Gathering factual information about the incident and operational actions of personnel, visual inspection of the site and object of the accident.
2. Studying technological and technical characteristics object of the accident.
3. History Analysis facility (similar accidents, maintenance and repair work carried out).
4. Formation of a working hypothesis, conducting additional research as necessary (if additional research disproves a hypothesis, a new one is put forward, the reliability of which is tested).
5. Determining the causes accidents that accompanied her technical factors, culprits (development of a confirmed working hypothesis).
6. Development emergency events.
7. Monitoring implementation of emergency events.

The information obtained can be used to solve a number of technical and technological issues, issues of material supply, personnel management, RS development.

It seems advisable to perform the following types of analysis:

• causal factor, which consists in identifying the characteristic problems of the enterprise (for example, insufficient qualifications of operating personnel, lack of stable and timely material and technical support, discrepancy between the volume and frequency of equipment repairs and the intensity of its operation, and others);
• spatial, the purpose of which is to determine the “vulnerabilities” of both individual machines and units, the complex of equipment of the enterprise as a whole;
• temporal, which is aimed at identifying seasonal patterns, cyclicity emergency situations, trends and forecasts of their occurrence.

The results of the analysis are the basis for the development of measures aimed not only and not so much at combating the consequences of accidents, but to a greater extent at eliminating their causes and preventing the possibility of recurrence in the future. [