Manufacturing of ball bearings. How bearings are made

A bearing is a functional unit that performs the function of supporting and guiding a rotating shaft and axle. The device is designed to reduce friction between the moving part of the mechanism, as well as its stationary elements.

Bearings reduce energy loss, eliminate heat and reduce wear of parts.

Leading manufacturers

Among the world's famous brands, experts especially highlight the following manufacturers:

• Swedish industrial group SKF supplies products to 130 countries;
• German manufacturer FAG;
• Slovak concern Kinex
• French company SNR - considered largest supplier for Europe;
• Japanese companies NSK, NTN and Koyo;
• American concern TIMKEN

To produce high-quality products, strict adherence to technological standards at all stages of production is mandatory. This requirement is usually met only by well-known world brands Ukrzakhidpostach company supplies bearings exclusively from leading brands, the quality of whose products has been tested by time.

Features and stages of production

The production of bearings requires the use of special grades of steel. For the rings and rolling elements, steel made from iron is selected, while the cage will require alloys of heavy and light metals such as cast iron, bronze, aluminum and brass.

Now developed large number specialized bearings, each of which has its own technological production chain. Regardless of this, all products undergo turning, pressure treatment, heat treatment, grinding, and assembly during the manufacturing process.

Ring production

These elements are manufactured according to the following scheme:

1. Blanks are prepared from metal pipes and rods according to the calculated diameter.
2. The initial processing is carried out by rolling and pressure.
3. Turning work is carried out aimed at cutting individual rings and general surface treatment.
4. Heating the rings to 850ºС, then rapid cooling to 40ºС.
5. Tempering of parts at a temperature of 170ºС.
6. Grinding of end, internal and external surfaces, raceways.
7. Final grinding of raceways to the required roughness values.

Manufacturing of rolling elements

The technological chain for the production of these parts is as follows:

1. Using a special steel wire of a certain diameter, the initial blanks are cut.
2. The parts are compressed with a special press to give them a spherical shape.
3. A final pressure treatment is carried out to achieve an allowance of 100 microns.
4. Heat treatment using the same method as for rings.
5. Sanding and polishing the product.

Separator production

To manufacture the separator, another technological chain will be required:

1. Preparation of the workpiece - steel sheet.
2. Punching holes in the sheet corresponding to the rolling elements.
3. Rough and finishing stamping of a workpiece, aimed at giving it the required shape.
4. Drilling holes for rivets.
5. Finishing holes.

Assembly

To assemble the bearing, it is necessary to insert the inner ring into the outer ring and place the rolling elements between them. Next, a separator is installed in two places using rivets. Before putting finished products on sale, a mandatory check of functionality, labeling and lubrication of the product is required.

In our company you can buy bearing rollers, balls and industrial bearings with delivery.To order, use our contacts

The perfect shape of the ball in the bearings evokes admiration and justifiable interest in the production method. The surface of the product is perfectly smooth, the shape is perfectly round. The question of how balls for bearings are made has a detailed answer.

Difficult process turns steel wire into a ball of the required diameter. Each stage of production is verified, because the product on which stable and reliable operation depends complex mechanisms, must have exactly specified parameters. The development of technology leads to the gradual replacement of familiar designs and machines with newer and more advanced ones. But bearings remain a popular and relevant part of the design of cars, factory machines, and various devices.

In order to understand how balls for bearings are made, you need to trace all the stages of technological progress.

1. Steel wire is cut into blanks that are characterized by a shape close to a ball. A wire is used whose diameter corresponds to the parameters of the ball. Then these blanks are rolled between disk dies with special grooves, the initially rough shape of the ball becomes more pronounced. For processing, enormous pressure is used, up to 20 tons. After such a running-in, the spherical blank has parameters that are only 100 crowns away from the required dimensions.
2. Forming, which can be cold or hot, is an important step in the production of balls. The wire is passed through an upsetting machine, which has special ball-shaped recesses. Steel discs are closed around the wire and the result is a workpiece in the form of balls with a rim. Then these balls are heated and hardened. Parts are annealed to ensure high strength and reliability.
3. The next stage is grinding the balls. In order to understand how balls for bearings are made, you need to carefully study all the stages. At the grinding stage, dimensional accuracy of parts up to 10 microns from the required level is achieved. Those rims that remain after the heading machine are separated from the balls. To do this, the ball is placed between two very thick sheets of metal, one of which is stationary and the second is rotating. Circular movements of the second sheet polish the ball. The polished products are separated from the rest through special holes. They pass through several chutes and are thus sorted by size. A machine is also used that adds shine to the finished products. The main final result is the production of balls of perfectly precise size and high hardness.
4. The final stage - the balls are washed, undergo quality control, and packaged.

The process is complex and requires special equipment. High-quality bearings must have balls with perfect sliding, which will give an absolutely smooth shape. The ball is responsible for the operation of the bearing (), and any extra micron can affect it. Therefore, it is especially important to control the size of the ball and the smoothness of its surface. It is imperative that high-quality steel wire is selected for production.

Bearing ball manufacturing technology

Ball production includes the following steps:

1. Stamping of blanks. The blanks are cut from a calibrated wire coil (rod) and processed on a cold heading machine or a helical rolling mill. The output is a ball with geometry defects (ring sagging, central protrusion).

2. Ripping. Rough abrasive processing of balls in drums with abrasive chips, during which geometric defects are removed.

3. Run-in. It is produced using disk dies, which are a lower fixed and upper rotating faceplate, equipped with cast iron disks of a special profile, resulting in semi-finished products with a tolerance of +100 microns from the required geometric size for subsequent grinding and finishing processes.

4. Heat treatment. For the production of bearing balls, steel grade ShKh15 is mainly used (bearing steel, 1.5% Cr, 0.95% C) - GOST 3722. Heat treatment is carried out in muffle furnaces and includes heating, annealing at 800 °C and quenching in oil - GOST 801-78. The balls after heat treatment have a hardness of 60-62 HRC.

5. Sanding. It is produced until the ball size is reached with a tolerance of +10 microns from the nominal one. Equipment used is similar to that used during the running-in phase, but more accurate.

6. Finishing. Used when it is necessary to obtain balls of higher precision.

As of 2016, in the production process of bearing balls at JSC VPZ, there is no separate stage of washing finished bearing balls. The entire flushing process involves using coolant (cutting fluid) during the abrasive machining stages of bearing balls. The use of coolant is necessary for heat removal, since in the contact areas of the part and equipment the temperature reaches 1000°C; as well as abrasive. The roughness and cleanliness of the surface depends on the coolant finished product, since contamination of the liquid leads to clogging of the grinding equipment and, as a result, the formation of burns. The use of coolant is carried out in accordance with GOST R 52237-2004. For steel ШХ15, it is recommended to use a coolant of the following composition: 0.2% - oleic acid, 0.5% - triethanolamine, 0.2% - sodium nitrite, 6% - sulfofresol, 93.1% - water.

Analysis of bearing products of JSC "VPZ"

In 2015, JSC VPZ sold bearing products in the industries indicated on pie chart Figure 3.

Figure 3 - Sales of bearing products by industry sector

From market analysis products sold we see that the largest share is occupied by automotive products. One of the common types of bearings used in cars is the ball bearing. An important criterion for car users is the low noise level inside the car, which is why it is important to take into account the quality of components, in particular bearings.

The company has research potential, therefore it is constantly expanding its product range, producing precision bearings, as well as bearing and other products according to customer drawings.

Main types of products:

Ball and roller bearings;

Repair kits;

Assembled products;

Railway bearings and rings;

Conveyor rollers;

Roller bearings;

Stainless steel bearings;

Bearings according to SPECIAL TU and ETU.

The company also has production capacity for mechanical processing of various mechanical engineering parts. The company has everything necessary equipment for carrying out operations such as:

Forging;

Foundry;

Heat treatment;

Stamping and more.

The plant also has its own testing center and provides services for all types of testing of rolling bearings.

The rotation node is important detail, providing movement during rolling or linear movement, it serves as a support or stop for a movable structure. More and more bearing manufacturing plants are being built in the Russian Federation. It's becoming profitable business, since such parts are used in all industries national economy(heavy and light industry, ship and automotive industry, agriculture).

Production methods and stages

There are two main types: sliding and rolling. We will look at steel products, where the elements that facilitate rotation are balls. This is the most popular type currently. They are divided into radial and thrust. The difference is that the former compensate for loads directed perpendicular to the shaft, while the latter are responsible for axial displacement.

The part consists of an outer and inner frame, metal elements and a device that ensures their correct distribution around the perimeter. For units operating in conditions of increased contamination, a boot washer is installed on one or both sides. It prevents the entry of abrasive particles from outside and limits the space in which the lubricant is located.

Bearing production technology begins with the preparation of the required steel grade. The plant receives metal of a certain grade in the form of round rods.

First, let's consider the issue of making clips:

• . Round bars are cut automatic line according to the dimensions required for this type.
• . A hole is made in a cylindrical blank using a press. The result is a rough washer.
• . This is followed by the rolling process. In this case, the part acquires parameters and shape that are roughly similar to the final product.
• . The next stage is turning work. On a numerically controlled machine, the outer and side surfaces and the groove are formed along which the rolling elements will move.
• . Next comes the phase of imparting the necessary physical qualities to the workpiece. In most cases, this is done by hardening. First, heating occurs to 850 degrees, then sharp cooling to a temperature of 40 to 50 ° C and tempering. In a special chamber, the part is heated to 170 and allowed to cool slowly.
• . Bringing to the required dimensions by grinding. On machines in automatic mode all parameters are refined to accuracy corresponding to GOST.
• . The last stage is polishing all surfaces to a clarity class of 0.06.

Materials

An important question for production is what steel are the bearing races made of? The most common material is branded:

• . ШХ15;
• . ShH15SG;
• . ShH20SG;
• . ШХ4.

They differ in the content of technological additives. The composition includes magnesium, silicon, carbon, chromium in amounts up to 2 percent and impurities of sulfur, phosphorus, nickel, copper in very limited quantities. Hardness is acquired by heat treatment.

For products that can withstand heavy loads, it is necessary to have a strong contact surface and a plastic middle. In this case, steel grades are used:

• . 15G1;
• . 18HGT;
• . 20Х2Н4А.

The planes are cemented. In this case, strength is achieved from 59 to 66 HRCe. The core remains softer with a score of around 36. Production process a little different from the previous one.

Industry requires units to operate in aggressive environments. For production in this case, steel grades 95Х18Ш and 110Х18МШД are used.

In foundries, in heat treatment units, products made from heat-resistant material are needed. In Russia they use 8Х4В9Ф2Ш and 8Х4М4В2Ф1Ш.

How balls for bearings are made at the factory, video

The production of such material is a high-precision production. It is necessary to achieve certain parameters at which friction will be minimized. This is usually a separate industry that provides rolling elements to assembly shops. It should be taken into account that the material is not only steel of different grades, but also ceramics, Si3N4. This is a completely different industrial cycle. They are used in units with high rotation speeds because they have less mass and are not subject to deformation when high temperatures, and pair (steel, silicon nitride) have better sliding performance.

Manufacturing technology of balls for bearings:

• . A larger diameter rod is taken and cut into cylinders of the required length.
• . The cold-exhibition machine is shaped into a ball with a characteristic belt. The workpiece has dimensions slightly larger than required. The surface has a fairly rough configuration.
• . The next stage is rolling between two rotating disks. The future rolling element takes on an almost ideal shape with some allowance.
• . Then the parts are processed in a roller cutter. Using abrasive materials, scale and burrs are removed from the surface.
• . Next, rolling occurs between two cast iron faceplates. In this case, dimensions close to the required ones are achieved.
• . While soft elements require hardening. They are subjected to heat treatment or carburization. It depends on what metal it is made from.
• . The final stage of production is grinding. The workpieces are continuously rolled between two discs, automatically mixing. The output is a product with a tolerance of 10 microns. If necessary, the accuracy can be increased even higher.
• . The final phase is washing with special solvents, quality control in an automatic way, during which culling and sorting takes place according to accuracy class.
• . The product is packaged and labeled in accordance with GOST, and sent to consumers. Part of the goods is used for the production of rolling units, and the rest is sold as a finished product.

Raw materials and how balls for bearings are made: video

A small part for the entire mechanism is one of the most complex in a technological sense. After all, it is very difficult to achieve smooth, round balls from a metal rod with precise dimensions down to hundredths of a micron, because an extra indicator can negatively affect the operation of the entire mechanism. The factories use special high-quality steel, regulated by GOST 3722-81:

• . Chrome-carbon sheet, type ШХ15. For indicators with higher hardness, ShKh4, ShKh20, 15 G 1, 12Kh18, 95Kh18, 18KhGT, 110Kh18, 8Kh4M4V2F1 are used to order.
• . Molybdenum. Used for making hunting shotgun pellets and balls special purpose. Copper, aluminum, brass, polyamides, polymers and cermets are added to the main component in small quantities.
• . IN lately a new alloy of synthetic material is used - silicon nitride. Products are made from it special purpose, capable of self-reinforcing.

We have determined what steel the bearings are made of. Steel balls are used for the production of rolling units. Separately, they are used in various sectors of the national economy. They are also indispensable in the automotive, paint, defense, cement, confectionery, chemical and agricultural industries. In addition, they can act as separate parts for deodorants and pen refills.

These devices are an integral part in the manufacture of wheels and rollers for warehouse equipment (hydraulic trolleys, lifters), for spare parts and furniture fittings. You can find the required part in the catalog of the MPlast online store. To do this, you need to enter the website and find the required product there, as well as decide on the price and form of payment.

In units operating in aggressive environments, balls with a high nickel content are used. Environmentally friendly shot is rolled from soft iron (lead causes more harm to the environment than low-carbon steel) and copper-plated shot, with a diameter of 4.5 for air guns.

The next step in manufacturing was the creation of rolling elements from ceramics. They have found their application in extreme conditions operation (jet engines, spindles in metalworking machines, Formula 1 cars.

Factories

In Russia there are more than two dozen large enterprises that produce such products. We will give some examples:

• . JSC "Moscow Bearing" Specializes in the production of parts for metro construction and railways.
• . OJSC "GPZ-2" - oldest plant, operating since 1916. It produces a huge range of small-sized products from 4 to 6770 grams. Supplies products to 50 countries.
• . Saratov has been operating since 1941. The product for consumers is balls.
• . Samara "ZPON" produces roller mechanisms different types(4000 titles). It has equipment production and its own research base.
• . Tomsk "ROLTOM" GPZ-5. It produces mechanisms with miniature sizes with a diameter of 2 mm to large ones - 22 cm.
• . Yekaterinburg plant No. 6 specializes in the production of spherical double-row products with increased radial load.
• . Baku gas processing plant-7.
• . Kharkovsky No. 8. The production range of products is from 30 g to 45 kg.
• . Samara plant number 9 produces roller units.
• . GPZ-10 Rostov-on-Don has been operating since 1938 and produces parts for agricultural machinery, processing equipment and metallurgy.

On Russian market products arrive from factories different countries. The most popular bearings are made:

• . In the People's Republic of China by AAA. It specializes in the manufacture of parts for the automotive industry.
• . And India at the ABC Bearings concern. The company has been operating successfully for more than 50 years and imports its products to many countries around the world.
• . In Slovakia by AKE. This new brand is not inferior in quality to famous brands. Every year the range of manufactured products increases, the cost of which is significantly lower than that of other imported analogues.

Species

These mechanisms can be divided into groups according to the direction of the load, according to the elements on which the holders rest, according to the presence or absence of a rotating spacer and according to the material of manufacture.

What are they made of and how are they made?

The product can be radial and supporting, with full or partial rotation. Depending on the operating conditions, it is manufactured in the form of: outer and inner races (lower and upper), sliding sleeve (washer), lubrication system (forced, natural, air).

Polished surfaces due to lubricant or thanks physical properties gaskets provide long-lasting easy sliding. Raw materials for production: steel, cast iron, bronze, fluoroplastic, babbitt, aluminum, ceramics. Pairs with a minimum friction coefficient are selected. What metal the bearing bushing is made of directly determines in which cage it will rotate.

Rolling

Such units are divided into radial, thrust and complex. This determines the direction of the load. The first are divided into three main classes: ball, roller, needle. These species can be with or without restrictive rings, with one or two anthers, and completely open.

The second type is created on the basis of spherical elements, cylindrical and conical rollers. Completely collapsible varieties are available. The third - combines the qualities of the first and second in terms of perceived effort. There are also open and closed types.

Depending on the materials for the manufacture of rolling bearings, there are several subclasses:

• . standard (most common);
• . designed for increased loads;
• . designed for extreme temperatures;
• . resistant to aggressive environments.

For special conditions (ultra-high rotation speeds, strong heating, the need to operate in the presence of acids and alkalis), products made of ceramics, silicon nitride, and plastics are used. There are models where the sliding layer is a gas or a magnetic field.

Device

It is not possible to describe all the diversity. Fundamentally, this mechanism consists of an external and internal support (they can be replaced by a housing part), a sliding gasket (lubricant, a separator with rolling elements, a bushing).

The most common type is done like this:

• . two washers with grooves having the required radius of curvature;
• . balls fixed with a special device at the same distance from each other along the entire perimeter;
• . When the clips move, friction decreases sharply.

How to assemble ball bearings: video

The process looks like this:

• . The appropriately prepared clips are inserted into one another and touch at a single point. As a result, a space is created on the side opposite to the contact through which the balls can be inserted.
• . The number of rolling elements with this design is limited. The next step is to distribute them evenly around the perimeter. In this case, the inner ring is automatically centered relative to the outer one.
• . Specially made separator halves are installed below and above. The standard product is made from carbon steel. But there are varieties when fixation occurs due to a brass or plastic part. The latter consists of one part and simply snaps into place.
• . On a special machine, the two halves of the holding device are connected with rivets made of metal through a pre-prepared hole.
• . The product is washed and lubricated (with lithol, cyatim, graphite or a preservative compound).
• . Protective boots are installed. They can be metal, plastic or composite.
• . Next, the product is marked according to GOST standards and packed in boxes.

Assembly of the support product consists of creating a separator that holds the rolling elements in certain places. The edges of the device are rolled. It is sold in the form of three parts (the upper and lower washer, and the assembly itself).

For high loads it is necessary to create more points of contact. It is impossible to place additional balls into the classic mechanism. Then manufacturers make technological recesses in the disks, through which the number of contact points becomes maximum. Subsequently, the classic riveting of the separator occurs.

One of the trusted suppliers is the MPlast company. It sells products based on bearings produced in Russia by factories with an ideal reputation.