JP7221711B2 - ball bearing - Google Patents

Description

The present invention relates to a ball bearing provided with a resin retainer.

In EVs (electric vehicles) and PHEVs (plug-in hybrid electric vehicles), in order to obtain driving force comparable to that of engine-driven vehicles, electric motors, which are driving sources, are increasing in rotation speed. In order to support this high-speed rotating shaft, ball bearings suitable for high-speed operation are used.

Some ball bearings designed for high-speed rotation use a resin retainer. In particular, crown-type retainers are used when the assemblability and cost of the bearing are important. In general, crown-shaped retainers have a plurality of pocket portions that are open on the inner periphery, the outer periphery, and one side surface in the axial direction of the retainer. The pocket portion is formed in a concave curved surface shape that wraps around the ball. The opening width of the pocket portion on one side surface in the axial direction of the retainer is set smaller than the diameter of the ball. The elastic deformation that widens the width of the opening is maintained by pressing the opening edge of the pocket portion on one axial side of the retainer toward one axial direction against the plurality of balls arranged between the inner and outer raceway surfaces. The ball is placed in the pocket through the opening of the vessel. The elastically restored pocket portion becomes engageable with the ball toward the other axial direction. The engagement restricts the movement of the retainer in the other axial direction.

In the case of a general crown-shaped retainer, deformation due to centrifugal force during high-speed rotation is a problem. That is, since the protruding portion of the retainer extending in one axial direction to form the pocket portion is a cantilever beam, the pocket portion is inclined radially outward in one axial direction due to centrifugal force. , the annular portion of the retainer is twisted accordingly. For this reason, there is concern that the pocket portion will interfere with the balls and the outer ring, resulting in the generation of abrasion powder, abnormal heat generation, and shortened service life.

In order to suppress the influence of such centrifugal force, in the crown-shaped retainer of Patent Document 1, the axial thickness of the intermediate portion located between the pocket portions adjacent in the circumferential direction is reduced to reduce the thickness of the pocket portion. While securing the depth in the axial direction, the weight of the protruding portion forming the pocket portion is reduced. Further, by making the thickness in the axial direction at the intermediate portion larger than the thickness in the axial direction at the bottom of the pocket portion, the strength of the retainer is ensured.

Further, in the retainer disclosed in Patent Document 2, the retainer is composed of a crown-shaped retainer body and a metal deformation preventing member attached to the tip of the protruding portion of the retainer body, and the protruding portion is deformed by centrifugal force. It is prevented from tilting radially outward.

Further, in the crown-shaped retainer disclosed in Patent Document 3, the outer diameter of the protruding portion forming the pocket portion is gradually reduced from the axially intermediate portion toward the distal end, thereby reducing the weight and reducing the influence of centrifugal force. are doing. Furthermore, by setting the contact between the balls and the pocket portion at a position radially inward of the pitch circle diameter of the balls, the radially inward force from the balls acts on the retainer to deformation of the retainer is suppressed.

JP 2016-169766 A JP 2007-285506 A Japanese Unexamined Patent Application Publication No. 2013-200006

However, when the movement of the retainer in the other axial direction is restricted by the engagement of the pocket portions and the balls as in Patent Document 1, it is necessary to extend the pocket portions in one axial direction from the center of the balls with a sufficient margin. be. Therefore, the tip of the pocket is easily affected by the centrifugal force, and there is a limit to suppressing deformation of the retainer due to the centrifugal force.

In addition, if a deformation prevention member is attached to the crown-shaped retainer main body to resist centrifugal force as in Patent Document 2, an additional assembly process and separate component costs are required, resulting in an increase in cost. Furthermore, there is a concern that the deformation prevention member will fall off.

Further, as in Patent Document 3, if the outer diameter of the protruding portion forming the pocket portion is gradually reduced from the intermediate position in the axial direction to the tip, it is possible to weaken the influence of the centrifugal force, but the engagement between the pocket portion and the ball is the same as in Patent Document 1 in that the movement of the retainer in the other axial direction is restricted by . Further, when the force from the balls directed radially inward is applied to the pocket portion to suppress the deformation of the cage due to the centrifugal force, if the cage is deformed due to the centrifugal force, the tip portion of the pocket portion may be deformed. There is a concern that the radially inner side is directly connected to strong contact with the ball, and abnormal wear progresses at the contact portion.

Furthermore, the high-speed rotation of electric motors in EVs and PHEVs is still progressing, and in ball bearings that support the rotating shaft of electric motors, the value of dmn (ball pitch circle diameter × number of revolutions per minute) is 2,000,000. may exceed. When aiming for a ball bearing that can be used in such high-speed rotation, it is important not only to prevent abnormal heat generation by countering centrifugal force, but also to prevent normal heat generation, so the shear resistance of the lubricant between the cage and the balls is important. can also be a problem. If the temperature of the cage can be maintained at 120°C or less, relatively inexpensive engineering plastics can be used. This is because it will have to be adopted.

In view of the background described above, the problem to be solved by the present invention is to suppress deformation of the retainer due to centrifugal force in a ball bearing in which the pocket portion of the resin retainer is open on one side surface in the axial direction. To suppress the shear resistance of lubricating oil between a pocket part and balls.

In order to achieve the above object, the present invention provides an outer raceway ring having an outer raceway surface, an inner raceway ring having an inner raceway surface, the outer raceway surface and the inner raceway surface. a plurality of balls arranged between the raceway surface of the ball and a resin retainer for evenly arranging the plurality of balls in a circumferential direction, wherein the retainer determines the circumferential positions of the balls In a ball bearing having pocket portions at a plurality of locations in the circumferential direction, the pocket portions opening to one side surface of the retainer in the axial direction, the outer bearing ring and the inner raceway At least one of the rings has an engaging portion radially protruding from the inner circumference including the raceway surface or the outer circumference at the other position in the axial direction from the raceway surface, and the cage is arranged at the other axial position. It has an engaging portion arranged so as to be capable of engaging with the locking portion, and when the depth in the axial direction of the pocket portion is H and the diameter of the ball is d, the relationship between H and d is: , 0.15d≦H≦0.65d, and the engaging portion is disposed at the other position in the axial direction than the plurality of pocket portions.

According to the above configuration, since the movement of the retainer in the other axial direction can be restricted by the engagement between the engaging portion of the retainer and the locking portion of the bearing ring, the depth of the pocket portion in the axial direction It is possible to set the relationship between H and the ball diameter d to H≦0.65d. Here, if H>0.65d, the depth of the pocket portion is the same as that of the conventional example in which the movement of the retainer in the other axial direction can be restricted only by the engagement between the pocket portion and the balls. It becomes meaningless to adopt the part and the locking part. Also, if H<0.15d, it becomes difficult to maintain the circumferential position of the ball at the pocket portion. A pocket portion is formed by arranging the locking portion at the other position in the axial direction than the raceway surface of the bearing ring, and arranging the corresponding engaging portion at the other position in the axial direction than the pocket portion of the retainer. Since there is no engaging portion in the protruding portion for holding the ball, it is possible to avoid a situation in which the pocket portion is likely to come into abnormal contact with the ball due to the centrifugal force acting on the engaging portion during high-speed rotation. On top of that, if H ≤ 0.65d, the protruding portion is shortened in the axial direction to reduce weight, and the retainer is less susceptible to centrifugal force during high-speed rotation, suppressing deformation of the retainer due to centrifugal force. At the same time, the shear resistance between the pocket portion and the balls can be suppressed.

Preferably, the relationship between the depth H of the pocket portion and the diameter d of the ball is set to H<0.5d. By doing so, deformation of the retainer due to centrifugal force and the aforementioned shear resistance can be further suppressed.

In addition, the engaging portion has a projection that forms a space between the engaging portion and the locking portion that narrows in the axial direction in the circumferential direction, and the axial direction is formed between the projection and the locking portion. Clearance should be set. With this configuration, since an axial clearance is provided between the engaging portion and the locking portion, an oil film is formed between the two surfaces of the engaging portion and the locking portion that slide in the circumferential direction. In addition, when the protrusion drags the lubricating oil toward the narrower space, a wedge effect that generates dynamic pressure is generated, thereby promoting the formation of an oil film and preventing wear of the engaging portion and the locking portion. Further, when the peripheral speed difference between the engaging portion and the engaging portion increases, it becomes possible to achieve a thickness of the oil film that completely separates the engaging portion from the engaging portion. That is, when the above-mentioned peripheral speed difference becomes equal to or greater than a predetermined value, the frictional state between the engaging portion and the engaging portion can be changed to a fluid lubricating state. In the fluid lubricated state, the engaging portion and the engaging portion engage with each other through the oil film when restricting the movement of the retainer in the other axial direction. can be done.

Further, an axial clearance is set between the engaging portion and the locking portion, and the arithmetic mean roughness of two surfaces of the engaging portion and the locking portion that slide in the circumferential direction is Ra is preferably 0.2 or less. Since an axial clearance is provided between the engaging portion and the locking portion, when using a ball bearing with oil lubrication, an oil film is formed between the two surfaces of the engaging portion and the locking portion that slide in the circumferential direction. formation occurs. In particular, when the ball bearing is used in high-speed rotation, the difference in peripheral speed in the circumferential direction between the two surfaces increases, so the minimum oil film thickness _hmin between the two surfaces should be 1.5 μm or more. can be expected. Since the surface properties of these two surfaces can be considered to follow a normal distribution, if the arithmetic mean roughness Ra (μm) of each of these two surfaces is set to 0.2 or less, a friction state with an oil film parameter Λ>3 can be expected. can. If .LAMBDA.>3, it is considered that fluid lubrication is substantially achieved, and wear of the engaging portion and the locking portion can be effectively prevented.

Moreover, it is preferable that the retainer has two or more of the engaging portions, and these engaging portions are distributed at two or more locations in the circumferential direction. With this configuration, when the retainer is incorporated between the inner and outer races, the engaging portions can easily escape from the locking portions, making it easy to force the engaging portions to pass over the locking portions. .

Moreover, it is preferable that the engaging portion has a chamfered portion having a shape in which the diameter difference between the tip of the engaging portion and the tip thereof is gradually increased toward the other axial direction. With this arrangement, when the retainer is assembled between the inner and outer races, the engagement portion slides over the engagement portion and easily escapes from the engagement portion, so the engagement portion is forced to pass over the engagement portion. becomes easier.

Moreover, it is preferable that the engaging portion has a shape in which the diameter difference between the tip of the engaging portion and the tip is gradually increased in one direction in the axial direction. With this arrangement, when the retainer is assembled between the inner and outer races, the engagement portion slides over the engagement portion and easily escapes from the engagement portion, so the engagement portion is forced to pass over the engagement portion. becomes easier.

In addition, the locking portion has a receiving surface having a shape with an inclination angle of 10° or less toward the other axial direction toward the tip of the locking portion in the radial direction, and the engaging portion , may be arranged so as to be engageable with the receiving surface toward the other axial direction. With this configuration, when the engaging portion of the retainer engages the engaging portion of the bearing ring toward the other axial direction, the engaging portion is less likely to escape from the engaging portion, so that the retainer moves toward the other axial direction. You can prevent it from falling out.

In addition, at least one of the bearing rings has a groove portion extending in the radial direction and continuing along the entire circumference in the circumferential direction at a position on the other side in the axial direction than the raceway surface in the inner circumference or the outer circumference including the raceway surface. The locking portion preferably constitutes a portion of the inner circumference or outer circumference including the raceway surface from the other end in the axial direction to the groove bottom of the groove portion. By doing so, the other axial side of the groove can be used as a locking portion at the position where the seal groove for mounting a general seal is present, and thus the axial layout of a general ball bearing can be adopted. can.

Further, the outer bearing ring and the inner bearing ring each have the locking portion, and the retainer is the outer engaging portion corresponding to the locking portion of the outer bearing ring. and the inner engaging portion corresponding to the engaging portion of the inner bearing ring. With this configuration, the engagement between the inner and outer engaging portions of the retainer and the engaging portions of the inner and outer bearing rings restricts movement of the retainer in the other axial direction. It is possible to further prevent it from coming off.

As described above, the present invention can suppress deformation of the retainer due to centrifugal force and suppress shear resistance of the lubricating oil between the pocket and the balls by adopting its configuration.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the ball bearing which concerns on 1st embodiment of this invention Conceptual diagram showing an example of use of the ball bearing according to the first embodiment Left side view of the retainer according to the first embodiment A plan view of the retainer shown in FIG. FIG. 2 is a partially enlarged cross-sectional view of the engaging portion of FIG. 1; The left side view of the retainer which concerns on 2nd embodiment of this invention. A plan view of the retainer shown in FIG. The left side view of the retainer which concerns on 3rd embodiment of this invention. The left side view of the retainer which concerns on 4th embodiment of this invention. Sectional drawing which shows the ball bearing which concerns on 4th embodiment of this invention Sectional drawing which shows the ball bearing which concerns on 5th embodiment of this invention FIG. 6 is a partially enlarged cross-sectional view showing an engaging portion according to a sixth embodiment of the present invention; Left side view of the retainer according to the sixth embodiment The right side view of the engaging part which concerns on 6th embodiment. Partially enlarged cross-sectional view of line XV-XV in FIG. The left side view of the engaging part which concerns on 7th embodiment of this invention. Sectional drawing which shows the ball bearing which concerns on 8th embodiment of this invention

A first embodiment as an example of a ball bearing according to the present invention will be described with reference to FIGS. 1 to 5. FIG.

A ball bearing B shown in FIG. and a plurality of balls 4 arranged so as to be circumferentially arranged at a predetermined pitch by the retainer 3.

Here, the direction along the rotation center line of the retainer is called the "axial direction". Also, the direction along the circumference of the cage around the rotation center line is referred to as the "circumferential direction". A direction orthogonal to the rotation center line of the retainer is called a "radial direction". Also, the concept of one axial direction and the other axial direction is the direction considered with respect to the retainer. Also, the inner diameter or outer diameter means the diameter of a virtual inscribed circle or virtual circumscribed circle concentric with the rotation center line of the retainer. In FIG. 1, the left-right direction corresponds to the axial direction, with one axial direction being left and the other axial direction being right. In FIG. 1, the radial direction corresponds to the vertical direction, the upward direction corresponds to radially outward, and the downward direction corresponds to radially inward.

The outer bearing ring 1 is an annular bearing component having an inner circumference including an outer raceway surface 1a. The inner race 2 is an annular bearing component having an outer circumference that includes an inner raceway surface 2a.

The bearing rings 1, 2 and the balls 4 are each made of steel.

The outer raceway surface 1a and the inner raceway surface 2a are formed of raceway grooves each having an arcuate cross-section and arranged in the central portion of the width of the raceway ring. The illustrated ball bearing B exemplifies a deep groove ball bearing.

In general, one of the outer bearing ring 1 and the inner bearing ring 2 is fixed for rotation with a rotating shaft (not shown) and the other is a housing (not shown) stationary relative to the rotating shaft. fixed to It is assumed that the ball bearing B in the illustrated example can be operated at a dmn of 2,200,000. As an application for such high-speed operation, for example, as conceptually shown in FIG. The motor 5 is, for example, an electric motor that serves as a drive source for an automobile.

As shown in FIG. 1, the ball 4 is arranged between the outer raceway surface 1a and the inner raceway surface 2a. The retainer 3 evenly arranges a plurality of balls 4 in the circumferential direction.

As shown in FIGS. 1, 3, and 4, the retainer 3 has pocket portions 3a at a plurality of locations in the circumferential direction that retain the circumferential positions of the balls 4. It means the whole of the bearing components that are continuous so as to be able to rotate in the circumferential direction integrally with the plurality of pocket portions 3a.

The retainer 3 is made of resin. Here, "made of resin" means that the entire retainer 3 is made of resin. The concept of the resin includes a single type, a mixture of two or more types, and a mixture of reinforcing materials (such as glass fiber, carbon fiber, etc.) mixed with one or more types of resin as a base material (so-called fiber reinforced resin). is wrapped. In the case of a ball bearing that allows dmn of 2 million, it is preferable to adopt a fiber-reinforced resin.

The retainer 3 employs an engineering plastic as the aforementioned resin. Engineering plastics generally refer to plastics having a heat resistance of 100° C. or higher and 120° C. or lower, a strength of 50 MPa or higher, and a flexural modulus of 2.4 GPa or higher.

Main engineering plastics include, for example, polyamides (PA, PA6, PA9, PA46, PA66), polyacetal (POM), polycarbonate (PC), polybutylene terephthalate (PBT), and the like. (PA46 or 66 + glass fiber) and (PA9T + carbon fiber).

The entire retainer 3 is integrally formed by injection molding using an axially split mold.

As shown in FIGS. 1 and 3, the pocket portion 3a is a concave surface portion that forms a space for housing the ball 4, and has a shape that is open on one axial side surface of the retainer 3. As shown in FIG. The plurality of pocket portions 3a are arranged at a constant pitch in the circumferential direction. Balls 4 are housed in pocket portions 3a through openings on the left side surface of cage 3, as in a general crown-shaped cage.

As shown in FIGS. 1, 3, and 4, the pocket portion 3a of the illustrated example has a shape that is also open to the outer periphery and the inner periphery of the retainer 3, and the ball 4 can come into contact with the pocket portion 3a. A portion has a concave spherical shape along the ball 4. - 特許庁That is, the ball 4 faces the pocket portion 3a both in the circumferential direction, the other in the axial direction, and radially inwardly and outwardly.

A pocket clearance is set between the pocket portion 3a and the ball 4. - 特許庁The retainer 3 can move freely with respect to the plurality of balls 4 within the pocket clearance. When the retainer 3 is deformed by centrifugal force and the pocket clearance becomes negative, the pocket portion 3a interferes with the balls 4 and they come into contact with each other abnormally strongly. If the pocket clearance is increased, the interference is less likely to occur, but the acoustic characteristics deteriorate. That is, when the ball bearing B rotates at a high speed, the ball 4 comes into contact with the pocket portion 3a due to the advance and lag of the ball 4 when entering and exiting the load bearing region of the ball bearing B. As shown in FIG. This contact maintains the position of the balls 4 in the circumferential direction. It is preferable to set the pocket clearance to 0.2 mm or less in order to bring the acoustic characteristics at high speed rotation to a practical level.

Here, as shown in FIG. 1, the axial depth of the pocket portion 3a is H, and the diameter of the ball 4 (ball diameter) is d. The depth H corresponds to the distance between an imaginary radial plane in contact with the tip of the pocket portion 3a and an imaginary radial plane in contact with the bottom of the pocket portion 3a. Here, the virtual radial plane is a virtual plane orthogonal to the rotation centerline of the retainer 3 . The tip of the pocket portion 3a is the portion of the pocket portion 3a that is located on one side in the axial direction. The bottom of the pocket portion 3a is the portion of the pocket portion 3a that is located at the other end in the axial direction. The depth H corresponds to the axial length of a protruding portion of the retainer 3 protruding in one axial direction so as to form the pocket portion 3a.

When the ball bearing B rotates at a high speed and the ball 4 comes into contact with the pocket portion 3a in the circumferential direction due to the lead/lag of the ball 4 as described above, the ball 4 must not climb over the pocket portion 3a. . In order to prevent such a situation, 0.15d≦H is set.

On the other hand, as the depth H of the pocket portion 3a is reduced, the pocket portion 3a can be made smaller in the radial direction and the circumferential direction, and the cage shape can be made less susceptible to centrifugal force. This is also advantageous in that by shortening the radial length of the ring portion of the retainer 3, the facing range between the pocket portion 3a and the balls 4 is reduced, and the shear resistance of the lubricating oil between them is suppressed. . That is, the smaller the H/d, the smaller the facing area between the balls 4 and the pocket portions 3a. As a result, the shear resistance of the lubricant between the balls 4 and the pocket portions 3a becomes smaller. can be reduced. Further, when the shear resistance is reduced, the amount of heat generated in the vicinity of the retainer 3 can be suppressed, which is suitable for high-speed rotation as in the present embodiment.

Table 1 shows the results of evaluating the ball overriding the pocket and the deformation of the cage due to centrifugal force at various H/d.

In Table 1, the item "climbing over" shows the evaluation results of the above-mentioned climbing prevention performance, the item "influence of centrifugal force" shows the evaluation results of the performance of suppressing pocket deformation due to centrifugal force, and the item " The item "Shear resistance" indicates the evaluation result of the shear resistance of the lubricating oil between the ball and the pocket portion, and the item "Comprehensive evaluation" indicates the evaluation result of the suitability of the ball bearing for high-speed operation. In each of these items, "⊚" means very good, "◯" means good, and "X" means bad.

As shown in Table 1, when H>0.65d, the pockets are such that the movement of the cage in the other axial direction can be restricted only by the engagement between the pocket portions and the balls, as in the case of the conventional crown-shaped cage. However, if an engineering plastic retainer is used, there is a particular concern that the pockets will interfere with the balls at high-speed rotation where the dmn value exceeds 2,000,000.

When H≤0.65d, the axial length of the protruding portion of the retainer 3 for forming the pocket portion 3a is shortened to reduce the weight of the protruding portion, so that the retainer 3 is free from the centrifugal force. It can make you less susceptible.

In the illustrated cage 3, H<0.5d. More specifically, it is set to H=0.45d.

When H≤0.5d, the pocket portion 3a is not undercut in the above-described injection molding, and the shape of the pocket portion 3a is not distorted when the mold is released. Therefore, the dimensional accuracy of the pocket portion 3a is improved.

If H<0.5d, the opening width of the pocket portion 3a on the left side surface of the retainer 3 must be smaller than the diameter d of the ball 4. Therefore, the pocket portion 3a cannot engage with the ball 4 toward the other axial direction. Even if 0.5d<H≦0.65d is set and the shape of the pocket portion is made to be capable of contacting the ball 4 toward the right, the contact is shallow. Therefore, when the ball bearing B rotates at a high speed, there is concern that the movement of the retainer 3 in the other axial direction may be restricted only by the contact thereof. In particular, when H<0.5d, when the ball 4 comes into contact with the pocket portion 3a, the direction of contact becomes close to the other axial direction, and the component force of the ball 4 pushing the pocket portion 3a toward the other axial direction increases. .

Therefore, a structure described later is adopted in which the retainer 3 can engage with at least one of the inner and outer races 1 and 2 toward the other axial direction, and the engagement is utilized to move the retainer 3 in the other axial direction. By restricting the movement to , the relationship between the depth H and the ball diameter d can be set to H≦0.65d.

Specifically, the outer bearing ring 1 includes a locking portion 1b used for restricting the movement of the retainer 3 in the other axial direction, and a groove portion machined to form the locking portion 1b. 1c.

The groove portion 1c is radially deep in the inner circumference of the outer raceway ring 1, and continues along the entire circumference in the circumferential direction at a position on the other side of the raceway surface 1a in the axial direction. The groove portion 1c has a constant cross-sectional shape along the entire circumferential direction.

The locking portion 1b constitutes a portion of the inner circumference of the outer bearing ring 1 from the groove bottom of the groove portion 1c to the other end in the axial direction.

As shown in FIG. 5, the locking portion 1b has a shape in which the inclination angle _θ1 toward the other axial direction toward the radially inner side (the direction approaching the tip of the locking portion 1b) is 10° or less. It has a face 1d. Here, the tip of the engaging portion 1b is the highest portion in the radial direction of the engaging portion 1b. A portion from the tip of the engaging portion 1b to the receiving surface 1d has an arcuate cross section. A portion from the receiving surface 1d of the engaging portion 1b to the groove bottom of the groove portion 1c has an arcuate cross section.

A portion of the groove portion 1c facing the receiving surface 1d in the axial direction forms an inclined surface 1e. A portion of the groove portion 1c from the groove bottom to the inclined surface 1e has the same arcuate cross-section as the engaging portion 1b. The inclined surface 1e continues up to a shoulder that defines the inner diameter of the outer bearing ring 1. As shown in FIG. The inclined surface 1e has an inclination angle _.theta.2 toward one side in the axial direction radially inward (away from the groove bottom). The tilt angle _θ2 is set larger than the tilt angle _θ1 . When the groove portion 1c is ground by the rotary grindstone, shavings are easily discharged along the steep inclined surface 1e.

Moreover, the locking portion 1b has a chamfered portion 1g that connects the front end thereof and the other width surface 1f of the bearing ring 1 in the axial direction. Here, the width surfaces refer to surface portions at both ends that define the axial length (total length) of a certain member. The width surface 1f of the bearing ring 1 is a side surface along the radial direction that defines the width of the bearing ring.

The chamfered portion 1g has a shape in which the inner diameter is gradually increased from the tip of the locking portion 1b toward the other axial direction (the difference in diameter from the tip is gradually increased). The chamfered portion 1g has a length of 0.2 mm or more toward the other axial direction from the tip of the locking portion 1b, and has an inclination angle _θ3 of 45° or more radially outward toward the other axial direction. .

On the other hand, as shown in FIG. 1, the retainer 3 has an engaging portion 3b that is arranged to engage with the engaging portion 1b toward the other axial direction. The engaging portion 3b is arranged in the retainer 3 at the other position in the axial direction than the plurality of pocket portions 3a.

As shown in FIGS. 1 and 3, the outer and inner circumferences of the retainer 3 are formed with cylindrical surfaces on the other side in the axial direction than the plurality of pocket portions 3a. The cylindrical surface on the inner peripheral side of the retainer 3 has a wider width in the axial direction than the cylindrical surface on the outer peripheral side.

As shown in FIGS. 1 and 4, the engaging portion 3b is positioned at the other end in the axial direction of the outer periphery of the retainer 3, and has a height in the radial direction from the outer cylindrical surface of the retainer 3. there is

As shown in FIG. 3, the engaging portion 3b is an arcuate projecting piece extending in the circumferential direction. The retainer 3 has two or more engaging portions 3b. The engaging portions 3b are distributed at equal intervals in the circumferential direction. The position of the center of the engaging portion 3b in the circumferential direction coincides with the position of the center of the pocket portion 3a in the circumferential direction. The circumferential length of the engaging portion 3b is greater than the circumferential length of the pocket portion 3a. A space between the engaging portions 3b adjacent in the circumferential direction is open in both axial directions.

Since the bottom of the pocket portion 3a is thin, it becomes a weak portion of the retainer 3 in terms of strength. Considering the angle around the rotation center line of the retainer 3, the engaging portion 3b is arranged in an angle range that includes the angle range in which the pocket portion 3a exists. It can be relieved at the portion 3b.

As shown in FIGS. 3 and 4, on one side surface of the retainer 3 in the axial direction, the portion between the tips of the pocket portions 3a adjacent in the circumferential direction is a circular arc surface that continues along the circumferential direction. The width surface 3c is shaped like a shape. A portion of the outer periphery of the retainer 3 between the pocket portions 3a adjacent in the circumferential direction is formed into an arcuate surface having the same diameter as the cylindrical surface of the retainer 3 on the outer peripheral side. A portion of the inner circumference of the retainer 3 between the circumferentially adjacent pocket portions 3a is formed into an arcuate surface having the same diameter as the cylindrical surface on the inner peripheral side of the retainer 3 .

As shown in FIGS. 1 and 5, the engaging portion 3b is arranged to face the receiving surface 1d of the locking portion 1b in the other axial direction. A portion of the right side surface of the engaging portion 3b that faces the receiving surface 1d in the other axial direction is a facing end portion 3d that is shaped along the receiving surface 1d.

The engaging portion 3b has a shape in which the outer diameter is gradually reduced from the tip of the engaging portion 3b toward one axial direction (the diameter difference from the tip is gradually increased). Here, the tip of the engaging portion 3b is the highest portion in the radial direction of the engaging portion 3b. A portion of the engaging portion 3b facing the inclined surface 1e in one axial direction is an inclined surface portion 3e having a shape along the inclined surface 1e. A portion of the engaging portion 3b from the slope portion 3e to the opposing end portion 3d through the tip has an arcuate cross-section.

The process of assembling the cage 3 between the inner and outer bearing rings 1 and 2 so as to accommodate the balls 4 in the pocket portions 3a of the cage 3 is the same as that of the conventional crown type cage. In this assembling process, these engaging portions 3b are pressed against the locking portion 1b from the other position in the axial direction toward the one axial direction. Therefore, the retainer 3 including the engaging portion 3b is elastically deformed, and the engaging portion 3b is forced to pass over the engaging portion 1b and enter the groove portion 1c. As a result, the engaging portion 3b is arranged in a state capable of being engaged with the locking portion 1b toward the right.

At this time, since the engaging portions 3b are distributed in the circumferential direction, they are likely to be elastically deformed so as to escape from the locking portion 1b.

Further, when the engaging portion 3b is pressed against the chamfered portion 1g of the locking portion 1b, the above-mentioned inclination angle _θ3 of the chamfered portion 1g makes it easier for the engaging portion 3b to slide on the chamfered portion 1g. is likely to be strongly pushed in the other axial direction and diagonally inward direction. For this reason, deformation of the retainer 3 (bending of the engaging portion 3b and twisting deformation of the retainer 3) that causes the engaging portion 3b to escape from the locking portion 1b so that the tip of the engaging portion 3b reaches the tip of the locking portion 1b. ) is more likely to occur. In addition, the chamfered portion 1g may have a rounded shape like an R surface.

Further, when the engaging portion 3b is pressed against the engaging portion 1b, the engaging portion 3b easily slides on the engaging portion 1b due to the above-described gradually decreasing outer diameter shape of the engaging portion 3b. It becomes easy to be strongly pushed in the oblique direction of . Therefore, deformation of the retainer 3 that causes the engaging portion 3b to escape from the engaging portion 1b so that the tip of the engaging portion 3b reaches the tip of the engaging portion 1b is likely to occur.

Axial and radial clearances are set between the engaging portion 3b and the entire groove portion 1c including the locking portion 1b. Note that the clearance is exaggerated.

Since a radial clearance is set between the engaging portion 3b and the groove portion 1c, lubricating oil can be supplied from the outside of the bearing between the engaging portion 3b and the locking portion 1b. , lubricating oil inside the bearing is also supplied. In addition, the space between the engaging portions 3b adjacent in the circumferential direction facilitates the lubricating oil inside the bearing to reach between the engaging portion 3b and the locking portion 1b. Further, when the ball bearing rotates at high speed, a pump action is generated based on the peripheral speed difference on the inclined surface 1e of the groove portion 1c, and the lubricating oil entrained on the inclined surface 1e tends to flow toward the locking portion 1b.

An axial clearance C between the engaging portion 3b and the engaging portion 1b is set between the receiving surface 1d of the engaging portion 1b and the opposite end portion 3d of the engaging portion 3b.

When the ball bearing rotates at high speed, the balls 4 come into contact with the pocket portions 3a, and the other force component in the axial direction is applied to the retainer 3. When the retainer 3 tries to move in the other axial direction beyond the clearance C, each of the engaging portions 3b engages with the locking portion 1b toward the other axial direction. This engagement prevents further movement of the retainer 3 in the other axial direction, so that the retainer 3 does not come off in the other axial direction.

At this time, the opposing end portion 3d of the engaging portion 3b is engaged with the receiving surface 1d of the engaging portion 1b. Since the receiving surface 1d has an inclination angle _θ2 of 10° or less to the right inward in the radial direction, a large radially inward force component is not generated. Therefore, the retainer 3 is not deformed enough to release the engaging portion 3b from the engaging portion 1b so that the tip of the engaging portion 3b reaches the tip of the engaging portion 1b.

The clearance C is set sufficiently larger than 1.5 μm. This is to enable formation of an oil film with a minimum thickness of 1.5 μm between the receiving surface 1d and the opposed end 3d when the ball bearing rotates at high speed.

Moreover, the clearance C is set to a value within a range in which the circumferential position of the ball 4 can be maintained by the pocket portion 3a when the engaging portion 3b and the locking portion 1b are engaged with each other.

The retainer 3 may be of a rolling-element-guided type or a race-guided type. If a clearance larger than the pocket clearance is set between the cage 3 and the outer bearing ring 1 as a whole and between the cage 3 and the inner bearing ring 2 as a whole, a plurality of cages 3 can be arranged. It is of a rolling element guide type that is guided in the radial direction by the balls 4 of the rollers. In the case of the rolling element guide type, a gap is secured between the engaging portion 3b and the bearing ring 1 (bearing ring having the locking portion 1b) to avoid contact between the engaging portion 3b and the bearing ring 1, thereby removing the engaging portion. Wear such that the height of 3b is reduced can be prevented.

Further, when the pocket clearance is set larger than the clearance between the engaging portion 3b and the groove portion 1c (including the locking portion 1b), even if the retainer 3 is deformed by the centrifugal force, , it is possible to make it difficult for each pocket portion 3a to hold the ball 4 (that is, to make it difficult to interfere). In this case, since it becomes a raceway guide type retainer using the engaging portion 3b, it is suitable when it is possible to substantially eliminate wear of the engaging portion 3b due to relative rotation with respect to the groove portion 1c by fluid lubrication. .

In order to realize such fluid lubrication, the arithmetic mean roughness Ra of the two surfaces sliding in the circumferential direction of the engaging portion 3b and the groove portion 1c including the locking portion 1b should be 0.2 μm or less. Preferably. Here, the arithmetic mean roughness Ra is defined in JIS B601:2001 "Product Geometric Characteristic Specification (GPS)-Surface Texture: Profile Method-Terms, Definitions and Surface Texture Parameters".

It can be considered that the surface properties of the engaging portion 3b and the groove portion 1c follow a normal distribution. Therefore, it is considered that the root-mean-square roughness σ ₁ of the engaging portion 3b including the opposing end portion 3d and the root-mean-square roughness σ ₂ of the groove portion 1c including the receiving surface 1d are both 1.25 Ra. The oil film parameter _Λ determined by the minimum oil film thickness h _min /√(σ ₁ ² +σ ₂ ² ) is Λ >3. If Λ>3, it is considered that the frictional state between the opposing end 3d and the receiving surface 1d is substantially fluid lubricating.

In the case of applications such as supporting the rotating shaft of an electric motor such as an EV, the ball bearing B _should be set at a rotational speed ( difference in peripheral speed due to relative rotation between the retainer 3 and the bearing ring 1). Therefore, the friction state between the engaging portion 3b and the groove portion 1c can be kept in the fluid lubricating state during most of the operating time.

The ball bearing B according to the first embodiment is as described above. Movement of the retainer 3 in the other axial direction shown in FIGS. It can be regulated by the engagement of the locking portion 1b. For this reason, in the ball bearing B according to the first embodiment, the relationship between the axial depth H of the pocket portion 3a having an open shape on one axial side surface of the retainer 3 and the diameter d of the ball 4 is H≤0.65d can be set.

Further, in the ball bearing B according to the first embodiment, the locking portion 1b is arranged at the other position in the axial direction than the raceway surface 1a of the bearing ring 1, and the corresponding engaging portion 3b is arranged at the pocket portion 3a of the retainer 3. , the engaging portion 3b does not exist in the projecting portion for forming the pocket portion 3a. It is also possible to avoid a situation in which the pocket portion 3a is likely to come into abnormal contact with the ball 4 due to force.

Further, in the ball bearing B according to the first embodiment, since the depth H of the pocket portion 3a is less than or equal to 0.65d, the protruding portion is shortened to reduce the weight, thereby suppressing deformation of the retainer 3 due to centrifugal force. , the shear resistance between the pocket portion 3a and the ball 4 can be suppressed.

Further, in the ball bearing B according to the first embodiment, the relationship between the depth H of the pocket portion 3a and the diameter d of the ball 4 is set to H<0.5d. The aforementioned shear resistance can be further suppressed, and in the case of an injection molded product, the dimensional accuracy of the pocket portion 3a is improved.

Further, in the ball bearing B according to the first embodiment, an axial clearance C is set between the engaging portion 3b and the engaging portion 1b, and the engaging portion 3b and the engaging portion 1b are arranged in the circumferential direction relative to each other. Since each Ra of the opposing end 3d and the receiving surface 1d as two sliding surfaces is 0.2 or less, an oil film is formed between the opposing end 3d and the receiving surface 1d. When the minimum oil film thickness h _min at is 1.5 μm or more, a friction state (substantially fluid lubrication state) with an oil film parameter Λ>3 can be expected. Therefore, the ball bearing B according to the first embodiment can satisfactorily prevent wear of the engaging portion 3b and the locking portion 1b.

Further, in the ball bearing B according to the first embodiment, the retainer 3 has two or more engaging portions 3b (see also FIG. 3), and these engaging portions 3b are distributed at two or more locations in the circumferential direction. Therefore, when the retainer 3 is assembled between the inner and outer races 1 and 2, the engaging portions 3b can easily escape from the engaging portions 1b, and thus the engaging portions 3b are forcibly engaged. It is possible to make it easier to let the part 1b be exceeded.

Although it is possible to adopt a series of engaging portions on the entire circumference in the circumferential direction, a distributed arrangement is preferable because a strong force is required for forcible fitting to pass over the engaging portion.

Further, in the ball bearing B according to the first embodiment, since the engaging portion 1b has the chamfered portion 1g having a shape in which the diameter difference between the engaging portion 1b and the tip thereof gradually increases in the other axial direction from the tip thereof, the retainer 3 is When assembling between the inner and outer bearing rings 1 and 2, the engaging portion 3b slides on the engaging portion 1b and easily escapes from the engaging portion 1b. can make it easier to

Further, in the ball bearing B according to the first embodiment, since the engaging portion 3b has a shape in which the diameter difference between the engaging portion 3b and the tip thereof is gradually increased toward one axial direction from the tip thereof, the retainer 3 is arranged between the inner and outer races. 1 and 2, the engaging portion 3b slides over the engaging portion 1b to easily escape from the engaging portion 1b, and thus it is easy to force each engaging portion 3b to pass over the engaging portion 1b. can be

Further, the ball bearing B according to the first embodiment has a shape in which the inclination angle θ1 toward the other axial direction toward the radial direction approaching the tip of the locking portion _1b is 10° or less. Since the engaging portion 3b is arranged so as to be engageable with the receiving surface 1d toward the other axial direction, the engaging portion 3b is engaged with the locking portion 1b toward the other axial direction. When engaged, the engagement portion 3b is less likely to escape from the engagement portion 1b, and thus the retainer 3 can be prevented from slipping off in the other axial direction.

Further, in the ball bearing B according to the first embodiment, the inner circumference including the raceway surface 1a of the raceway ring 1 has a depth in the radial direction at the other position in the axial direction than the raceway surface 1a. It has a continuous groove portion 1c, and the locking portion 1b constitutes a portion of the inner circumference of the bearing ring 1 from the other end in the axial direction to the groove bottom of the groove portion 1c. The locking portion 1b can be provided on the other side of the groove portion 1c in the axial direction at the position where the seal groove portion is present, and a general ball bearing axial layout can be adopted.

Further, in the ball bearing B according to the first embodiment, the retainer 3 is made of engineering plastic, so the use of expensive super engineering plastic can be avoided, and the manufacturing cost of the retainer can be suppressed.

In the first embodiment, the ball bearing B provided with only one cage 3 was exemplified, but two cages may be provided. In this case, cages are arranged on both sides of the balls. In order to accommodate the balls in the pocket portions of the two retainers, the depth H of the pocket portions should be smaller than 0.5d so that the retainers on both sides of the balls do not abut each other in the axial direction. Since bearing ring 1 has portions corresponding to locking portion 1b and groove portion 1c on the opposite side, it is also possible to dispose the retainer on the opposite side.

In the first embodiment, the movement control performance of the retainer 3 is prioritized, so as is clear from FIG. is large, and the total circumferential extension of the entire space between the engaging portions 3b is smaller than the total circumferential extension of all the engaging portions 3b. can be changed in various ways. A second embodiment as an example thereof is shown in FIGS. 6 and 7. FIG. In addition, below, it stops at describing a difference with 1st embodiment. Also, please refer to FIG. 1 appropriately for the bearing rings and balls.

In the retainer 10 according to the second embodiment, the circumferential length of the engaging portions 10a is smaller than the space between the circumferentially adjacent engaging portions 10a. In addition, the total circumferential extension of all the engaging portions 10a is smaller than the total circumferential extension of the entire space between the engaging portions 10a. For these reasons, in the second embodiment, when the retainer 10 is incorporated, the engagement portion 10a is easily deformed so as to escape from the engagement portion 1b, and lubricating oil is supplied between the engagement portion 10a and the engagement portion 1b. can be made easier to supply.

Each engaging portion 10a is arranged at a position outside the angular range in which the aforementioned pocket portion 3a exists. Such an arrangement is suitable when the lubricating performance in the vicinity of the ball 4 is emphasized.

A third embodiment as another example is shown in FIG. In the retainer 20 according to the third embodiment, each engaging portion 20a is shorter in the circumferential direction than in the first embodiment while arranging the engaging portion 20a in the angular range in which the pocket portion 3a described above exists. This is intended to facilitate the incorporation of the retainer 20 .

In the first to third embodiments described above, the engaging portions are arranged only on the outer circumference of the retainer, but the engaging portions may be arranged on the inner and outer circumferences of the retainer. A fourth embodiment as an example thereof is shown in FIGS. 9 and 10. FIG.

The retainer 30 according to the fourth embodiment has an engaging portion 20a on the outer circumference and an engaging portion 30a on the inner circumference. The inner engaging portion 30a is also arranged in the angular range in which the aforementioned pocket portion 3a exists.

The inner bearing ring 31 has an inner raceway surface 31a, an inner locking portion 31b, and an inner groove portion 31c for forming the locking portion 31b. The arbitrary shape of the inner engaging portion 30a, locking portion 31b and groove portion 31c is only opposite to the outer engaging portion 20a, locking portion 1b and groove portion 1c with respect to the radial direction. , detailed description is omitted.

In the ball bearing according to the fourth embodiment, the outer bearing ring 1 and the inner bearing ring 31 have locking portions 1b and 31b, respectively, and the locking portion 1b of the outer bearing ring 1 of the retainer 30 Since the corresponding outer engaging portion 20a and the inner engaging portion 30a corresponding to the locking portion 31b of the inner bearing ring 31 are provided, the inner and outer engaging portions 20a, 30a of the retainer 30 can be , the engagement of the inner and outer races 1, 31 with the engaging portions 1b, 31b restricts the movement of the retainer 30 in the other axial direction. Therefore, the ball bearing according to the fourth embodiment can further prevent the retainer 30 from coming off in the other axial direction.

In the above-described first to fourth embodiments, a ball bearing provided with bearing rings for standard deep groove ball bearings in which the shoulders on both sides are at the same height with respect to the raceway surface is exemplified. It is also possible to change to races with different heights between the shoulders. Also, the engaging portion of the retainer may be arranged only on the inner periphery. FIG. 11 shows a fifth embodiment as an example thereof.

The outer bearing ring 41 according to the fifth embodiment has outer shoulders 41b and 41c on both sides with respect to the outer raceway surface 41a. The first outer shoulder 41b is higher than the second outer shoulder 41c.

The inner race 42 has inner shoulders 42b, 42c on opposite sides of the inner raceway surface 42a. The first inner shoulder 42b is higher than the second inner shoulder 42c.

The first outer shoulder 41b and the second inner shoulder 42c are arranged to face each other in the radial direction. The second outer shoulder 41c and the first inner shoulder 42b are arranged to face each other in the radial direction.

In the ball bearing according to the fifth embodiment, the load capacity of the thrust load in the direction in which the ball 4 contacts the first outer shoulder 41b and the first inner shoulder 42b is set to that of the first embodiment. can be improved by comparison. The second outer shoulder 41c and the second inner shoulder 42c have the same height as in the first embodiment.

The retainer 40 is positioned between a first outer shoulder 41b and a second inner shoulder 42c. That is, in FIG. 11, one axial direction with respect to the retainer 40 corresponds to the right side, and the other axial direction corresponds to the left side.

The radial length of the pocket portion 40a is shorter than in the first embodiment. This is because the first outer shoulder 41b is made higher than in the first embodiment, and the radial distance from the second inner shoulder 42c is narrowed. is.

The engaging portion 40b is provided only on the inner circumference of the retainer 40. As shown in FIG. Corresponding locking portions 42d and grooves 42e are provided on the inner bearing ring 42. As shown in FIG.

When the outer bearing ring 41 is a rotating ring, the peripheral speed of the first outer shoulder portion 41b with a relatively small inner diameter is slower than the peripheral speed of the second shoulder portion 41c with a relatively large inner diameter. . Based on this peripheral speed difference, the lubricating oil entrained on the first outer shoulder 41b has a relatively high pressure, and the lubricating oil entrained on the second outer shoulder 41c has a relatively low pressure. Therefore, a pumping action is generated to send the lubricating oil from the first outer shoulder portion 41b side to the second outer shoulder portion 41c side.

When the inner bearing ring 42 is a rotating ring, the peripheral speed of the second inner shoulder 42c with a relatively small outer diameter is the same as the peripheral speed of the first inner shoulder 42b with a relatively large outer diameter. slower than fast. Based on this peripheral speed difference, the lubricating oil entrained on the second inner shoulder 42c has a relatively high pressure, and the lubricating oil entrained on the first inner shoulder 42b has a relatively low pressure. Therefore, a pumping action is generated to send the lubricating oil from the second inner shoulder portion 42c side to the first inner shoulder portion 42b side.

Therefore, regardless of whether the outer bearing ring 41 or the inner bearing ring 42 is the rotating ring, the aforementioned pumping action of the rotating ring causes the lubricating oil to flow to the first outer shoulder 41b and the second outer shoulder 41b. from between the second inner shoulder 42c to between the second outer shoulder 41c and the first inner shoulder 42b. The flow of lubricating oil into and out of the bearing can be adjusted depending on whether the retainer is located upstream or downstream of the flow of lubricating oil caused by this pumping action.

In the illustrated example, since the retainer 40 is arranged only on the upstream side, it is difficult for lubricating oil to flow into the inside of the bearing (the annular space between the outer bearing ring 41 and the inner bearing ring 42). easy to flow out. Therefore, it is difficult for lubricating oil to accumulate excessively inside the bearing.

When the retainer is arranged only on the downstream side, lubricating oil tends to flow into the bearing from the upstream side and is less likely to flow out of the bearing, thereby preventing excessive outflow of lubricating oil.

Also, depending on the lubricating environment, it is possible to arrange two cages upstream and downstream. In this case, another retainer can be arranged using the groove portion 1c of the outer bearing ring 41 . Arranging cages on the upstream and downstream sides suppresses the inflow and outflow of the lubricating oil, and is particularly suitable when the lubricating oil is diluted and has a low viscosity.

In the above-described embodiment, Ra of the engaging portion and the like is suitable for fluid lubrication. A sixth embodiment as an example thereof is shown in FIGS. 12 to 15. FIG.

The engaging portion 50a of the retainer 50 according to the sixth embodiment has a first projection 50b on the other side surface in the axial direction and a second projection 50c on the one side surface in the axial direction.

The first projection 50b and the second projection 50c each have a height in the axial direction and extend straight in the radial direction. Two or more first protrusions 50b are distributed over the entire circumferential length of the engaging portion 50a. These first projections 50b are arranged at a constant pitch in the circumferential direction. Two or more secondary protrusions 50c are arranged similarly to the primary protrusions 50b. The phases of the first protrusion 50b and the second protrusion 50c are the same. Both protrusions 50b and 50c form a series at the tip of the engaging portion 50a.

As shown in FIGS. 12 and 15, an axial clearance _C1 is set between the engaging portion 50a and the engaging portion 1b. The first projection 50b forms a space between itself and the engaging portion 1b, which narrows in the axial direction by a length of (C ₂ -C ₁ ) in the circumferential direction.

Circumferentially adjacent first protrusions 50b cannot contact the engaging portion 1b. Lubricating oil enters the gaps between the adjacent first projections 50b. When the ball bearing rotates, the engaging portion 50a slides on the engaging portion 1b. The lubricating oil existing in the gap is dragged by the first protrusion 50b between the protrusion 50b and the engaging portion 1b. At this time, since the space is narrowed by (C ₂ -C ₁ ), a dynamic pressure is generated and a wedge effect is produced in which the pressure of the oil film increases. As a result, the oil film becomes thicker, forming an oil film that completely separates the first protrusion 50b from the engaging portion 1b. Therefore, the frictional state between the engaging portion 50a and the engaging portion 1b becomes a fluid lubricating state.

In the illustrated example, considering the length of the engaging portion 50a in the circumferential direction, two or more first protrusions 50b are dispersedly arranged so that the engaging portion 50a can contact the engaging portion 1b. is limited to the first projection 50b, but if the length of the engaging portion in the circumferential direction is short, the abutment portion can be reduced to the first projection by providing one first projection for each engaging portion. It would be possible to limit the Of course, in order to promote the formation of the oil film, it is better for the first projections 50b to pass through the receiving surface of the locking portion 1b one after another at high speed. 50b are preferably formed in a distributed arrangement.

Moreover, as shown in FIG. 15, the first protrusion 50b preferably has a semicircular shape in any cross section along the circumferential direction. If the first projection is sharp, the sharp tip of the first projection will be pressed against the oil film by the thrust force applied from the ball to the retainer 50 in the other axial direction during high-speed rotation of the ball bearing, causing the oil film to run out. This is because it is likely to occur.

In addition, since the difference in peripheral speed between the engaging portion 50a and the engaging portion 1b is also important for realizing the fluid lubricating state, the first protrusion 50b is particularly important when the outer bearing ring 1 is a stationary ring. valid.

The second projection 50c strengthens the pump action of sending the lubricating oil in the other axial direction due to the peripheral speed difference due to the inclination thereof. When the space between the engaging portion 50a and the groove portion is narrowed like the space between the first projection 50b and the locking portion 1b, the second projection 50c is located between the axial one side surface of the engaging portion 50a and the raceway ring. It is effective to make the friction state between 1 into a fluid lubrication state. If the clearance is set so that there is no concern that one side surface of the engaging portion in the axial direction will slide on the bearing ring, no projection is required on the one side surface of the engaging portion 50a in the axial direction.

As described above, the ball bearing according to the sixth embodiment has the first protrusion 50b that forms a space between the engaging portion 50a and the locking portion 1b that narrows in the axial direction in the circumferential direction. Since the axial clearance _C1 is set between the first protrusion 50b and the engaging portion 1b, the oil film is not formed between the two surfaces of the engaging portion 50a and the engaging portion 1b which slide in the circumferential direction. Formation occurs, and the first projection 50b drags the lubricating oil toward the narrowing space, and a wedge effect that generates dynamic pressure is produced, promoting the formation of the oil film and reducing the wear of the engaging portion 50a and the locking portion 1b. can be prevented. Further, when the peripheral speed difference between the engaging portion 1b and the engaging portion 50a becomes greater than a predetermined value, the thickness of the oil film that completely separates the engaging portion 50a and the engaging portion 1b is realized, and the engaging portion 50a and the engaging portion 50a are engaged. The friction state between the stop portions 1b can also be a fluid lubrication state. In this fluid-lubricated state, the engaging portion 50a and the engaging portion 1b engage with each other through the oil film when restricting the movement of the retainer 50 in the other axial direction. Wear can be well prevented.

In the sixth embodiment, projections extending straight in the radial direction are used, but the projections may also provide a pump action. A seventh embodiment as an example thereof is shown in FIG.

A retainer 60 according to the seventh embodiment employs a projection 60b extending in a direction inclined in one circumferential direction toward the tip of an engaging portion 60a. During rotation of the ball bearing, the projection 60b imparts energy to the lubricating oil in a radial direction toward the tip of the engaging portion 60a, thereby producing a pumping action of the lubricating oil toward the tip of the engaging portion 60a. . In the illustrated example, the case of the projection 60b corresponding to the second projection of the sixth embodiment is shown, but the first projection may similarly produce a pump action.

In the first embodiment described above, the groove portion 1c as shown in FIG. 5 is adopted, but instead of the general groove portion 1c, it is conceivable to use a general seal groove portion as it is as the groove portion. FIG. 17 shows an eighth embodiment as an example thereof.

In the retainer 70 according to the eighth embodiment, the depth H of the pocket portion 70a is set to 0.25d or less. As compared with the first embodiment, the thrust applied from the balls 4 to the retainer 70 in the other axial direction is increased accordingly, so the ring portion of the retainer 70 is thickened in one axial direction.

The outer race 71 is for a typical sealed bearing. The locking portion 71a constitutes a portion on the other side in the axial direction of the seal mounting groove portion 71b. The groove portion 71b for attaching the seal generally has a shape in which the inclination angle θ ₁ >the inclination angle θ ₂ is set when considering the magnitude relationship between the inclination angles θ ₁ and θ ₂ in FIG.

The ball bearing according to the eighth embodiment can use the bearing ring 71 for a general sealed bearing, which is advantageous in reducing the manufacturing cost.

Each of the embodiments described so far may be combined as appropriate. For example, the lubricating projections of the sixth and seventh embodiments can be used in combination with any of the first to fifth and eighth embodiments. is.

It should be noted that facilitating the assembly of the cage 3 by the chamfered portion 1g and making it difficult to remove the cage 3 by the receiving surface 1d as in the first embodiment are independent of the adoption of the present invention. This technology can also be applied to bearing rings, and can be applied, for example, to mounting annular bearing parts such as seals and shields to bearing rings.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. Therefore, the scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the meaning and scope of equivalents of the scope of the claims.

1, 41, 71 Outer bearing ring 1a, 41a Outer raceway surface 1b, 31b, 42d, 71a Locking portion 1c, 31c, 42e, 71b Groove 1d Receiving surface 1g Chamfered portion 2, 31, 42 Inner Bearing rings 2a, 31a, 42a Inner raceway surfaces 3, 10, 20, 30, 40, 50, 60, 70 Cages 3a, 40a, 70a Pocket portions 3b, 10a, 20a, 30a, 40b, 50a, 60a, 70b Engaging portion 4 Balls 41b, 41c Outer shoulders 42b, 42c Inner shoulders 50b, 60b Projection B Ball bearing

Claims (9)

an outer raceway ring having an outer raceway surface; an inner raceway ring having an inner raceway surface; a ball and a resin retainer for evenly arranging the plurality of balls in a circumferential direction,
The retainer has pocket portions at a plurality of locations in the circumferential direction for maintaining the circumferential positions of the balls,
In a ball bearing in which the pocket portion is open on one side surface in the axial direction of the retainer,
At least one of the outer bearing ring and the inner bearing ring has a locking portion protruding radially at a position axially opposite the raceway surface of the inner circumference including the raceway surface or the outer circumference including the raceway surface. have
the retainer has an engaging portion arranged so as to be engageable with the locking portion toward the other axial direction;
When the axial depth of the pocket portion is H and the diameter of the ball is d, the relationship between H and d is set to 0.15d≦H≦0.65d,
The engaging portion is arranged at the other position in the axial direction than the plurality of pocket portions,
An axial clearance is set between the engaging portion and the locking portion,
A ball bearing, wherein an arithmetic average roughness Ra of two surfaces of the engaging portion and the engaging portion that slide in the circumferential direction is 0.2 or less. 2. The ball bearing according to claim 1, wherein the relationship between the depth H of said pocket portion and the diameter d of said ball is set to H<0.5d. The engaging portion has a projection that forms a space between the engaging portion and the locking portion that narrows in the axial direction in the circumferential direction, and an axial clearance is provided between the projection and the locking portion. 3. The ball bearing according to claim 1 or 2. 4. The ball bearing according to any one of claims 1 to 3 , wherein the retainer has two or more of the engaging portions, and these engaging portions are distributed at two or more locations in the circumferential direction. 5. The ball bearing according to any one of claims 1 to 4 , wherein the engaging portion has a chamfered portion having a shape in which a diameter difference from the tip of the engaging portion gradually increases toward the other axial direction. . 6. The ball bearing according to any one of claims 1 to 5 , wherein the engaging portion has a shape in which the diameter difference between the tip of the engaging portion and the tip is gradually increased toward one axial direction. The locking portion has a receiving surface with an inclination angle of 10° or less toward the other axial direction toward the tip of the locking portion in the radial direction, and the engaging portion is a shaft. The ball bearing according to any one of claims 1 to 6 , arranged so as to be engageable with the receiving surface in the other direction. said at least one raceway ring has a groove portion extending radially to a depth in the radial direction at a position on the other side of said raceway surface in the axial direction between the inner circumference and the outer circumference including said raceway surface and continuing along the entire circumferential direction;
8. The locking portion according to any one of claims 1 to 7 , wherein the locking portion forms a portion of the inner circumference or the outer circumference including the raceway surface from the other axial end to the groove bottom of the groove portion. ball bearings. the outer bearing ring and the inner bearing ring each have the locking portion,
The retainer has the outer engaging portion corresponding to the engaging portion of the outer bearing ring, and the inner engaging portion corresponding to the engaging portion of the inner bearing ring. A ball bearing according to any one of claims 1 to 8 .

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