How to determine the bearing number by the inner size. Bearings: standards, dimensions

How to determine the bearing number by the inner size. Bearings: standards, dimensions

20.04.2019

How to determine the bearing size?

Bearing fit information is useful when you need to replace an outdated part with a new one. Marking will help to cope with this task.

1. The first two digits on the right contain information about the diameter of the hole inside the part. If the diameter does not exceed 2 cm, then the numbers indicate: 00 - O 10 mm; 01 - O 12 mm; 02 - O 15 mm and 03 - O 17 mm.

2. When the hole diameter value is in the range from 2 cm to 49.5 cm, the two numbers on the right must be multiplied by 5. The result is the bearing seat size.

3. The third and seventh digits contain information about the rolling bearing series. The third is in the outer diameter, the seventh is in width or height.

4. The fourth digit indicates the type of part in question: roller or ball, double row or single row, radial or thrust.

5. The fifth and sixth digits indicate the design in which the bearing is made.

6. The left side also contains information about which accuracy class the part can be attributed to.

Attention! A satisfactory accuracy class is indicated by numbers from 0 to 5. The best option with a ratio of price and quality - 6th class of accuracy. The numbers 7 and 8 mean that you are actually holding production waste in your hands.

How to determine the hole diameter?

To determine the diameter of the hole, you will need a ruler, a caliper, a micrometric caliper and a caliper.

1. If the measurements do not need to be high-precision, you can get by with a regular ruler. This method is most often used in everyday life. The meter must be applied to the bearing bore at the diameter level and count the number of divisions that fit in the diameter.

2. Use a bore gauge to determine the size of inaccurate holes. The instrument must be inserted into the hole, the shackle is pressed against the hole wall and the caliper is fixed so that the second shackle is in contact with the hole wall. You can also measure the size of the nutrometer solution using a regular ruler.

Attention! The inaccuracy of the result obtained will be from 0.2 to 0.5 mm.

3. Hole diameters larger than 10 mm can be measured with high accuracy using a vernier caliper. The device must be placed in the hole and its lips parted so that they rest against the edges. The diameter will be displayed on the scale with an accuracy of tenths of a millimeter. This method is only suitable for measuring the bore diameter near the end face of the bearing.

4. A micrometric caliper will also help to cope with the task. The main thing is that the tool is perpendicular to the axis of the hole. To do this, it is necessary that one end rests on the surface of the hole, and the second one moves in the diametrical plane.

The use of rolling bearings in mechanisms makes it possible to produce machines of a higher accuracy class. Machines based on these structural elements are more reliable and have a longer service life. In addition, their use reduces operating costs.

The capabilities of the assembly in which the rolling bearing is used is determined by how accurately this part is installed. The distance from the base to the axis of rotation and from the base to the end of the shaft, as well as the radial and end runout, must be within certain limits of accuracy.

During the assembly process, it is necessary to strive so that the bearing races are not deformed. Form seats in the bearing housing and on the shaft must satisfy the shape and roughness technical requirements, no scratches or burrs.

Differences from plain bearings

There are two types of moving parts in mechanisms: bearings based on sliding friction and bearings based on rolling friction.

When using the former, the working surfaces of the housing and shaft mutually move and interact, being separated most often by lubricants and a sliding liner. The support works when there is pure sliding in the parts that come into contact.

In the second version of the supports, rolling elements (these can be rollers or balls) are placed in the gap between the surfaces that move mutually. In this case, the bearings work using rolling friction. In such cases, instead of bronze, babbitt or plastic liners in bearings where rolling friction is applied, ball or roller bearings of steel.

In accordance with the nature of the load of rotation supports, they are radial, when a radial load acts on the support, thrust, when the support is subjected to only axial loads, and radial-thrust, when both types of loads act on the support together.

Each type of support is characterized by its size, design, specifications for production, installation and maintenance.

Rolling bearings and plain bearings have a different mechanism for resistance to movement and for determining the wear of parts of movable bearings. The type of required node is determined on the basis of an assessment of the operating procedure of the mechanism or its individual nodes.

Advantages and disadvantages

Rolling and sliding bearings have both pluses and minuses. Rolling bearings can be preferred over plain bearings due to the lower level of friction at low speeds and when starting from a standstill. Also, rolling bearings have smaller dimensions along the axes, which makes it easier to assemble the structures of self-aligning bearings, without requiring a long time for difficult individual fitting of the liners and their running-in. This is especially important for trunnions with large diameters, operating under heavy loads, with high rotational speeds and temperatures.

When a rolling bearing is used, the quality of lubrication of machine parts and assemblies is improved, the quality of their maintenance is improved, the life of the seating surfaces of the cylinder necks and shafts is extended. Thus, they are the best fit for the vast majority of equipment supports.

True, in addition to the advantages, rolling bearings have a number of disadvantages.

For example, large dimensions. Such structural elements are widely represented in machine-building equipment, are produced in small batches and are very expensive. The rolling bearing is inferior to competitors in such parameters as radial dimensions, weight and rigidity.

It is very difficult to choose them correctly when high rotational speeds are combined with the action of high loads. It is well known that with an increase in the load and speed of rotation of the unit, its durability decreases. For example, if the load is increased by a quarter compared to the previous one, then the service life is halved, and if the load is doubled, the durability becomes 10 times less.

Marking and dimensions according to GOST

Requirements for assemblies and parts are formulated by GOST. Rolling bearings are described by GOST 520-2002.

The following parameters formed the basis of the symbols:

  • the diameter that the bearing hole has;
  • series of widths (or heights) and series of diameters;
  • types of bearings;
  • technical implementation.

How to correctly determine the dimensions of rolling bearings by marking? The notation table will help to cope with this task.

All of the above parameters are indicated by signs (or numbers). What numbers the bearing marking consists of depends on the places they occupy in its symbol, if you read from left to right:

Dimensions

To find out how the dimensions of bearings depend on their series, the table of bearing sizes allows. It allows you to link the series to the outer and inner diameter and width.

Dimensions of rolling bearings. Table 1.

Width

External diameter

Inner diameter

This is a table of rolling bearings, one of many tables describing this species structural elements.

Classification

One of the features by which rolling bearings are classified is the shape of the rolling elements. In accordance with it, bearings can be ball and roller. Ball rolling bodies, as the name implies, are exclusively spherical in shape. Roller rolling elements can be cylindrical, barrel-shaped or cone-shaped.

The next sign of classification is the direction of load perceived by the rolling bearing. By given feature distinguish bearings:

  • radial, which perceive only radial or mainly radial loads;
  • radial-thrust, able to perceive both radial and axial loads.

It should be noted that adjustable bearings are not able to function without axle load. Thrust are able to perceive only axial forces. Thrust-radial type work both with axial and with small radial loads.

There is also a classification of rolling bearings depending on how many rows of rolling elements they consist of. They are single row and double row.

In accordance with such a characteristic as sensitivity to misalignment, self-aligning bearings are distinguished. They are able to function normally even if a misalignment of up to 3 ° occurs.

Tolerance and landing system

Rolling bearings are widely used. They are produced at special factories and have full interchangeability in terms of surfaces, which are determined by the diameters of the rings: D - the outer diameter of the outer ring and d - the inner diameter of the inner ring.

The interchangeability of rolling bearings depends on the accuracy requirements:

  • ring width accuracy B;
  • accuracy of ring diameters d, D;
  • accuracy of ring surfaces;
  • radial and axial runout of the raceways, which determines the accuracy of rotation;
  • the accuracy of the gap that is formed at operating parameters between the raceways and the rolling elements.

The accuracy of assembly units is set by GOST. Rolling bearings must comply with the accuracy requirements of GOST 520-89, according to which there are 5 classes of their accuracy: 0; 6; 5; 4; 2. Most of the mechanisms use nodes of accuracy class 0. Nodes of accuracy classes above zero are used on high speeds rotation and in situations that require high accuracy of shaft rotation (for example, in precision machine tools). The accuracy class is indicated before marking through a dash.

To maintain the interchangeability of rolling bearings, the average taper and ovality of the bore and ring surfaces should not be more than half the tolerance for the average diameters Dc, dc. These parameters are calculated as the arithmetic mean of the maximum and minimum diameters, which are measured in 2 extreme sections of the ring.

Therefore, the tolerances of rolling bearings are assigned to the dimensions:

  • D and d;
  • Dc and dc;

The tolerances of the rings are determined only by the accuracy class of the bearing and its dimensions, regardless of the properties of the connection to the shaft and housing. Thus, a reduction in the range of bearings is achieved. The connection parameters of the rings with the shaft and the housing are determined by changing the tolerance fields of the shaft and hole.

Rolling bearing fits must be determined in such a way that the ring that rotates sits with an interference fit that would prevent running in and slipping of the ring along the seating surface during operation in the loaded mode.

Landings depend on such factors:

  • accuracy class;
  • type and size of loads;
  • type of loading.

Loading can be local, circulating and oscillatory.

In the case of local loading, only a radial load of constant magnitude and direction works at a single point on the bearing seating surface, transferred to a single point on the surface of the housing or shaft.

The ring, loaded in this way, must be installed so that there is a gap, and then gradually turn the ring, avoiding the local development of the ring, shaft and housing.

If circulating loading occurs, only the radial load, transmitted over the entire circumference of the bearing race, is exerted and is taken up sequentially by the housing or shaft surface. The ring, which experiences circulation loading, is installed on the housing or shaft with an interference fit.

When oscillatory loading occurs, two different radial loads come into play. One of them has a constant magnitude and direction, and the other is rotating. The resultant of these loads affects a limited section of the raceways of the rings, being transferred to some part on the seating surface of the housing or shaft.

Calculation

Calculation of rolling bearings for durability is carried out according to the method of fatigue spalling and for the prevention of plastic deformations.

For a constant mode, these structural elements are calculated according to the equivalent dynamic load, taking into account the nature and direction of the forces acting on the node. The equivalent load is assumed to provide the same service life as under real load conditions.

The load capacity of bearings is characterized by such parameters as the basic dynamic load rating C and the basic static load rating C0.
The first is a radial or axial load that can be sustained at a service life of 1 million revolutions. Base durability - durability under 90% reliability conditions.

Estimated life can be defined as number of revolutions in millions or hours of operation if, as a result, there is no evidence of metal fatigue in the form of flaking or spalling on the surfaces of 90% of the parts of the batch.

Single row deep groove ball bearings

The most popular type of rolling bearings. Often used in the construction of a wide variety of equipment. Among them are rollers of cardboard machines, gearboxes, electric motors. Used to resist radial loads, but can also be prepared to accept bilateral axial loads. Often they are used exclusively for axial loads, especially if the number of revolutions of the shaft is high and thrust bearings cannot be used. If the radial clearance increases, then the axial load carrying capacity of the bearing also becomes larger, since in this situation the bearings acquire the characteristics of angular contact bearings. Operation of bearings is possible if the relative misalignment of the inner and outer rings is not more than 20°.

As for the housing of rolling bearings, it is most often made of gray cast iron. The material for single-row bearing cages is steel stamping or anti-friction materials such as textolite, brass, bronze, duralumin. Recently, polyamide resins have been used for the production of separators. If the bearings are high class accuracy and massive turned cages, the centering of which occurs on the outer ring when using effective lubrication modes, then their operation is possible even at rotation speeds that exceed the limit described in the reference books.

Design types of single-row radial bearings:

  • having one protective washer;
  • having two protective washers;
  • having a groove on the outer ring and a setting ring;
  • having an adjusting ring and a protective washer;
  • having one-sided and two-sided seal;
  • having a groove for introducing balls without a cage.

Ball bearings with one shield

Manufactured exclusively with cages made by stamping. Their use at high speeds is undesirable. When working with such bearings, greases. A metal shield that is pressed into a groove in the outer ring can only hold grease on one side. WITH reverse side the grease that is packed into the bearing is limited by the cap or seal in the assembly. The resulting space is partly filled with lubricants selected for special operating conditions. This version of the design of the part always makes it possible to inspect it (in the place of the cover or seal) and carry out additional lubrication in the course of work.

Ball bearings with two shields

They have the same separators and speed parameters as the previous part, but the working lubricant of the rolling bearings is laid between the washers during assembly at the factory. This type of assembly is used in situations where it is impossible to make a seal in the assembly. So the design becomes simpler and the overall weight of the assembly is reduced. The internal parts of such a bearing cannot be inspected during operation.

Ball bearings with a groove on the outer ring

By means of a split mounting ring, which enters the groove on the ring from the outside, it is possible to fix the bearing inside the housing, which does not require the stop of the outer ring, into the shoulders of the housing for support. However, their ability to perceive radial loads is much greater than for axial ones. The use of adjusting rings makes the design simpler, reduces the size of the nodes and makes it possible to bore through the housing holes.

Sealed ball bearings

Bearings with a double-sided seal are widely used. It is a rubber membrane. The nodes where this seal is applied are characterized by good tightness. As a result, the factory grease does not leak and the ingress of third-party particles into it is excluded. The cages of such ball bearings are usually machined textolite or bronze. Although sealing them and contact type, they have the ability to work at higher rotation speeds.

Sealed ball bearings are often used in motor mounts. In these units, brush dust is released so intensely that it can quickly lead to breakage of other types of ball bearings.

Ball bearings with a groove for inserting balls without a cage

Their difference from other bearings of the classical design is the presence of milled grooves in the sides of the rings. Balls are inserted through these grooves. Since such a rolling bearing has more balls than a cage bearing, this gives a gain in load capacity. Their purpose is to work at low rotation speeds due to excessive friction of the rolling elements in contact. Where there are axial loads, it is better to abandon their use, since under their action the balls are often displaced in relation to the axis of the raceways.

As a constructive version of such ball bearings, there are nodes where there is a groove for inserting balls and protective washers.

These units are used without the use of lubrication in drying chambers and units that use rocking motion.

The use of rolling bearings in mechanisms makes it possible to produce machines of a higher accuracy class. Machines based on these structural elements are more reliable and have a longer service life. In addition, their use reduces operating costs.

The capabilities of the assembly in which the rolling bearing is used is determined by how accurately this part is installed. The distance from the base to the axis of rotation and from the base to the end of the shaft, as well as the radial and end runout, must be within certain limits of accuracy.

During the assembly process, it is necessary to strive so that the bearing races are not deformed. The shape of the seats in the bearing housing and on the shaft must meet the technical requirements in shape and roughness, without scratches and burrs.

Differences from plain bearings

There are two types of moving parts in mechanisms: bearings based on sliding friction and bearings based on rolling friction.

When using the former, the working surfaces of the housing and shaft mutually move and interact, being separated most often by lubricants and a sliding liner. The support works when there is pure sliding in the parts that come into contact.

In the second version of the supports, rolling elements (these can be rollers or balls) are placed in the gap between the surfaces that move mutually. In this case, the bearings work using rolling friction. In such cases, instead of bronze, babbitt or plastic liners in bearings where rolling friction is applied, steel ball or roller bearings are used.

In accordance with the nature of the load of rotation supports, they are radial, when a radial load acts on the support, thrust, when the support is subjected to only axial loads, and radial-thrust, when both types of loads act on the support together.

Each type of support is characterized by its size, design, specifications for production, installation and maintenance.

Rolling bearings and plain bearings have a different mechanism for resistance to movement and for determining the wear of parts of movable bearings. The type of required node is determined on the basis of an assessment of the operating procedure of the mechanism or its individual nodes.

Advantages and disadvantages

Rolling and sliding bearings have both pluses and minuses. Rolling bearings can be preferred over plain bearings due to the lower level of friction at low speeds and when starting from a standstill. Also, rolling bearings have smaller dimensions along the axes, which makes it easier to assemble the structures of self-aligning bearings, without requiring a long time for difficult individual fitting of the liners and their running-in. This is especially important for trunnions with large diameters, operating under heavy loads, with high rotational speeds and temperatures.

When a rolling bearing is used, the quality of lubrication of machine parts and assemblies is improved, the quality of their maintenance is improved, the life of the seating surfaces of the cylinder necks and shafts is extended. Thus, they are the best fit for the vast majority of equipment supports.

True, in addition to the advantages, rolling bearings have a number of disadvantages.

For example, large dimensions. Such structural elements are widely represented in machine-building equipment, are produced in small batches and are very expensive. The rolling bearing is inferior to competitors in such parameters as radial dimensions, weight and rigidity.

It is very difficult to choose them correctly when high rotational speeds are combined with the action of high loads. It is well known that with an increase in the load and speed of rotation of the unit, its durability decreases. For example, if the load is increased by a quarter compared to the previous one, then the service life is halved, and if the load is doubled, the durability becomes 10 times less.

Marking and dimensions according to GOST

Requirements for assemblies and parts are formulated by GOST. Rolling bearings are described by GOST 520-2002.

The following parameters formed the basis of the symbols:

  • the diameter that the bearing hole has;
  • series of widths (or heights) and series of diameters;
  • types of bearings;
  • technical implementation.

How to correctly determine the dimensions of rolling bearings by marking? The notation table will help to cope with this task.

All of the above parameters are indicated by signs (or numbers). What numbers the bearing marking consists of depends on the places they occupy in its symbol, if you read from left to right:

Dimensions

To find out how the dimensions of bearings depend on their series, the table of bearing sizes allows. It allows you to link the series to the outer and inner diameter and width.

Dimensions of rolling bearings. Table 1.

Width

External diameter

Inner diameter

This is a table of rolling bearings, one of many tables describing this type of structural element.

Classification

One of the features by which rolling bearings are classified is the shape of the rolling elements. In accordance with it, bearings can be ball and roller. Ball rolling bodies, as the name implies, are exclusively spherical in shape. Roller rolling elements can be cylindrical, barrel-shaped or cone-shaped.

The next sign of classification is the direction of load perceived by the rolling bearing. On this basis, bearings are distinguished:

  • radial, which perceive only radial or mainly radial loads;
  • radial-thrust, able to perceive both radial and axial loads.

It should be noted that adjustable bearings are not able to function without axle load. Thrust are able to perceive only axial forces. Thrust-radial type work both with axial and with small radial loads.

There is also a classification of rolling bearings depending on how many rows of rolling elements they consist of. They are single row and double row.

In accordance with such a characteristic as sensitivity to misalignment, self-aligning bearings are distinguished. They are able to function normally even if a misalignment of up to 3 ° occurs.

Tolerance and landing system

Rolling bearings are widely used. They are produced at special factories and have full interchangeability in terms of surfaces, which are determined by the diameters of the rings: D - the outer diameter of the outer ring and d - the inner diameter of the inner ring.

The interchangeability of rolling bearings depends on the accuracy requirements:

  • ring width accuracy B;
  • accuracy of ring diameters d, D;
  • accuracy of ring surfaces;
  • radial and axial runout of the raceways, which determines the accuracy of rotation;
  • the accuracy of the gap that is formed at operating parameters between the raceways and the rolling elements.

The accuracy of assembly units is set by GOST. Rolling bearings must comply with the accuracy requirements of GOST 520-89, according to which there are 5 classes of their accuracy: 0; 6; 5; 4; 2. Most of the mechanisms use units of accuracy class 0. Units of accuracy classes above zero are used at high rotation speeds and in situations requiring high shaft rotation accuracy (for example, in precision machine tools). The accuracy class is indicated before marking through a dash.

To maintain the interchangeability of rolling bearings, the average taper and ovality of the bore and ring surfaces should not be more than half the tolerance for the average diameters Dc, dc. These parameters are calculated as the arithmetic mean of the maximum and minimum diameters, which are measured in 2 extreme sections of the ring.

Therefore, the tolerances of rolling bearings are assigned to the dimensions:

  • D and d;
  • Dc and dc;

The tolerances of the rings are determined only by the accuracy class of the bearing and its dimensions, regardless of the properties of the connection to the shaft and housing. Thus, a reduction in the range of bearings is achieved. The connection parameters of the rings with the shaft and the housing are determined by changing the tolerance fields of the shaft and hole.

Rolling bearing fits must be determined in such a way that the ring that rotates sits with an interference fit that would prevent running in and slipping of the ring along the seating surface during operation in the loaded mode.

Landings depend on such factors:

  • accuracy class;
  • type and size of loads;
  • type of loading.

Loading can be local, circulating and oscillatory.

In the case of local loading, only a radial load of constant magnitude and direction works at a single point on the bearing seating surface, transferred to a single point on the surface of the housing or shaft.

The ring, loaded in this way, must be installed so that there is a gap, and then gradually turn the ring, avoiding the local development of the ring, shaft and housing.

If circulating loading occurs, only the radial load, transmitted over the entire circumference of the bearing race, is exerted and is taken up sequentially by the housing or shaft surface. The ring, which experiences circulation loading, is installed on the housing or shaft with an interference fit.

When oscillatory loading occurs, two different radial loads come into play. One of them has a constant magnitude and direction, and the other is rotating. The resultant of these loads affects a limited section of the raceways of the rings, being transferred to some part on the seating surface of the housing or shaft.

Calculation

Calculation of rolling bearings for durability is carried out according to the method of fatigue spalling and for the prevention of plastic deformations.

For a constant mode, these structural elements are calculated according to the equivalent dynamic load, taking into account the nature and direction of the forces acting on the node. The equivalent load is assumed to provide the same service life as under real load conditions.

The load capacity of bearings is characterized by such parameters as the basic dynamic load rating C and the basic static load rating C0.
The first is a radial or axial load that can be sustained at a service life of 1 million revolutions. Base durability - durability under 90% reliability conditions.

Estimated life can be defined as number of revolutions in millions or hours of operation if, as a result, there is no evidence of metal fatigue in the form of flaking or spalling on the surfaces of 90% of the parts of the batch.

Single row deep groove ball bearings

The most popular type of rolling bearings. Often used in the construction of a wide variety of equipment. Among them are rollers of cardboard machines, gearboxes, electric motors. They are used to resist radial loads, but can also be prepared to take double-sided axial loads. Often they are used exclusively for axial loads, especially if the number of revolutions of the shaft is high and thrust bearings cannot be used. If the radial clearance increases, then the axial load carrying capacity of the bearing also becomes larger, since in this situation the bearings acquire the characteristics of angular contact bearings. Operation of bearings is possible if the relative misalignment of the inner and outer rings is not more than 20°.

As for the housing of rolling bearings, it is most often made of gray cast iron. The material for single-row bearing cages is steel stamping or anti-friction materials such as textolite, brass, bronze, duralumin. Recently, polyamide resins have been used for the production of separators. If the bearings have a high accuracy class and massive turned cages, the centering of which occurs on the outer ring when using effective lubrication conditions, then it is possible to operate even at rotation speeds that exceed the limit described in the reference books.

Design types of single-row radial bearings:

  • having one protective washer;
  • having two protective washers;
  • having a groove on the outer ring and a setting ring;
  • having an adjusting ring and a protective washer;
  • having one-sided and two-sided seal;
  • having a groove for introducing balls without a cage.

Ball bearings with one shield

Manufactured exclusively with cages made by stamping. Their use at high speeds is undesirable. When working with such bearings, greases are used. A metal shield that is pressed into a groove in the outer ring can only hold grease on one side. On the reverse side, the grease that is embedded in the bearing is limited by a cover or seal in the assembly. The resulting space is partly filled with lubricants selected for special operating conditions. This version of the design of the part always makes it possible to inspect it (in the place of the cover or seal) and carry out additional lubrication in the course of work.

Ball bearings with two shields

They have the same separators and speed parameters as the previous part, but the working lubricant of the rolling bearings is laid between the washers during assembly at the factory. This type of assembly is used in situations where it is impossible to make a seal in the assembly. So the design becomes simpler and the overall weight of the assembly is reduced. The internal parts of such a bearing cannot be inspected during operation.

Ball bearings with a groove on the outer ring

By means of a split mounting ring, which enters the groove on the ring from the outside, it is possible to fix the bearing inside the housing, which does not require the stop of the outer ring, into the shoulders of the housing for support. However, their ability to perceive radial loads is much greater than for axial ones. The use of adjusting rings makes the design simpler, reduces the size of the nodes and makes it possible to bore through the housing holes.

Sealed ball bearings

Bearings with a double-sided seal are widely used. It is a rubber membrane. The nodes where this seal is applied are characterized by good tightness. As a result, the factory grease does not leak and the ingress of third-party particles into it is excluded. The cages of such ball bearings are usually machined textolite or bronze. Although their seal is of the contact type, they have the ability to operate at higher rotational speeds.

Sealed ball bearings are often used in motor mounts. In these units, brush dust is released so intensely that it can quickly lead to breakage of other types of ball bearings.

Ball bearings with a groove for inserting balls without a cage

Their difference from other bearings of the classical design is the presence of milled grooves in the sides of the rings. Balls are inserted through these grooves. Since such a rolling bearing has more balls than a cage bearing, this gives a gain in load capacity. Their purpose is to work at low rotation speeds due to excessive friction of the rolling elements in contact. Where there are axial loads, it is better to abandon their use, since under their action the balls are often displaced in relation to the axis of the raceways.

As a constructive version of such ball bearings, there are nodes where there is a groove for inserting balls and protective washers.

These units are used without the use of lubrication in drying chambers and units that use rocking motion.

How can I find out the bearing number?

The bearing number contains all the necessary technical data for the part. It is recommended to record important data immediately after purchasing a bearing or mechanism. If you have not done this, we offer several ways to determine the bearing number.

1. Find out data such as d, D and B - they will tell the size of the ball - and consult with technicians regarding the part number.

2. You can find the number in the catalog - all types of bearings with numbers and sizes are collected there. Select a part with the same dimensions as yours and you can name the part number.

3. There are special programs containing information about all sizes and models of bearings, for example, "AllBearings". As a rule, they work according to the general principle. In the "filter by size" column, enter the available data. The more indicators you know, the greater the accuracy of determining the number. You can narrow the search circle using the "designation" field, in which you must enter the brand of the part.

When it is necessary to find out the number of the bearing to be replaced, then it is necessary to analyze the information from the country of origin.

This is explained by the fact that there is no single block of standards governing the procedure for marking such products.

There are only three ISO standards that are advisory in nature:

  • 15:1998, which applies to rolling bearings of a radial type (except for tapered roller bearings);
  • 104:2002, regulates the marking of thrust roller bearings;
  • 355:1977 Tapered roller bearings.

Virtually all leading data producers technical devices(NSK, SKF, KOYO, FAG) have their own notation systems.

Russian bearings:

For Russian bearings, the basic standard that establishes the marking rules is 3189-89.

Where is the number

Having decided on the accessory of the product, we proceed to find out the number.

It can be affixed to the end of the product in two versions, short and expanded. In the first case, these are seven digits (the desired number). In the second one, to the left of it (separated by a hyphen) and to the right of it (beginning with a capital letter), there are two blocks of additional information.

When determining the number this information may go down.

In addition to the end part of the bearing, the number can be specified in the following places:

  • On branded packaging;
  • In the passport for the product;
  • In certification documents;
  • In waybills;
  • in the supply agreement.

If there is a structural drawing of the required product, the number must also be affixed to it.

The next option for determining the number is to find it in the catalog, this can be done in three sizes: internal and outer diameter and bearing width.

Many mechanisms currently in existence have bearings that allow them to rotate. Therefore, no rotating movement can be carried out without them. But even such a seemingly irreplaceable, but at the same time inconspicuous part of the mechanism, can be different both in size and in its technical characteristics, the diameter is especially taken into account, the dimensions of which are usually presented in the table. But whatever this detail may be, whatever it looks like, and whatever its specifications, it should perform only one task - to provide parts with rotation or the necessary rotation.

Rules for working with bearings

The bearing must be reliable, but sometimes the conditions under which it has to rotate do not correspond to its normal functioning. Also precisely and conditions can affect the fact that the bearing even in good conditions may suddenly fail.

That's why exist special rules exploitation this part, and they should be taken very seriously so that your part can work for as long as possible. For example, you should not overload it and make sure that it works only for the prescribed time period, and no more. Another rule should be considered that it should be selected so that it fits perfectly in size, diameter and other technical characteristics.

For example, in terms of size, you can find a variety of bearings: from miniature to the most gigantic sizes. There is another division: high-speed, low-speed, most accurate and others. All these divisions depend on where and how you are going to use this important element of the rotational movement.

Bearing design

Continuing the conversation about bearings, you can not miss its design. But in the element itself, which provides rotation, there are a lot of details of which it consists. And each of them should be taken very seriously, because if one of them fails, further operation of the bearing becomes simply impossible.

Bearing accessories:

  • Rolling bodies.
  • Bushings.
  • nuts.
  • Washers.
  • Rings.
  • screws.
  • Staples.
  • Balloons.

Of course, this list of bearing parts could go on and on, but it's still worth it study in practice and understand each element separately so that you can easily find it later.

Bearing types

There are several divisions of bearings into different types. At the heart of each such division is some sign, which is the main one for attributing important element to rotate to one type or another.

The first such division is based on how the load acts on the bearing and makes it work. But the load is also different. Accordingly, the bearing groups will be involved depending on how the load acts on it.

Groups depending on the action of the load:

  • Radial.
  • Persistent.
  • Radial thrust.

Let's take a closer look at each of these groups. So, the first group is radial. Such bearings can only act under the influence of a radial load. Rarely, they also act under axial load, if roller elements are used for rotation, which have the required diameter.

The second group - thrust elements for rotation. They work perfectly only when they feel the effects of axial loads. The third group is radial-thrust, which can act under any kind of load. They are not afraid of either radial or stubborn loads.

There is another division of bearings, which is based on the shape of the rolling elements, as well as their diameter. There are two types: ball and roller. The first type is ball. They are based on the rolling of such a body, which is similar in shape to balls and has a small diameter. The second type, roller, is based on a different form of rolling, that is, rollers of a certain diameter.

According to their design, bearings can be divided into two types: self-aligning and non-self-aligning. Such elements for rotation are also called spherical. Usually the division into these two species does not require any further explanation, but the main thing is not to forget about the diameter and as often as possible look into special tables, where they are presented with explanations.

There is another division of bearings, which depends not only on its diameter or size, but primarily on the rolling of the bearing bodies itself, which can be either roller or ball. Such an element for rotation can be, despite the shape of balls or rollers, one-, two-, three- or four-charged.

Bearing applicability

Knowing the diameter of the bearing, its design and dimensions, as well as the form of rolling: balls or rollers, it will be possible to determine how important this element will be for the user to rotate. This is especially important for those who are engaged in any kind of repair of equipment. For example, automotive, tractor or motorcycle equipment. But there is another applicability of bearings, which lies in knowing its size.

It is worth dwelling in more detail on how bearings are indicated in the tables. Usually, something is written on each element for rotation in letters and numbers. Such conventions denote the diameter including. How accurately the part is made is indicated by the letter that comes before the number.

The numbers indicate the size of the hole, what is special about its design, for example, ball or roller shapes of bodies. Usually the first two digits on the parts to be rotated indicate the diameter. But even diameter may vary., so you should be very attentive to the numbers.

So, the sliding parts that are needed for automobile structure, are not very strict about the diameter, and the fact that balls or rollers are used. Another thing is the part for rolling, where everything must be strictly instructions.

For example, sliding ball piece is widely applied for the manufacture of automotive parts. To load in this case was larger, it is necessary to use the balls correctly. It is worth remembering that the gutter must be larger than the ball. By the way, ball parts allow their use at different angles.

But roller parts provide high speed b, which is needed very often. You should not mix all types of bearings, otherwise, during operation, the balls will interfere with the operation of the rollers and vice versa. Therefore, it is worth monitoring the shape of the rolling, if it is a ball, then such a ball part must be used for its intended purpose. Nowadays, ball parts for rotation are used much more often than anything else.



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