JP6572754B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing.

  Many rolling bearings are used in various industrial equipment. The rolling bearing includes an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a cage that holds the rolling elements. For example, as shown in FIG. 11, in a rolling bearing 90 that supports the rotation shaft 95 in the housing 97, an inner ring 91 is attached by being fitted on the rotation shaft 95, and an outer ring 92 is an inner peripheral surface 98 of the housing 97. Is attached.

  In particular, when the rolling bearing 90 is a deep groove ball bearing and a bearing to which an axial load in one direction acts, the inner ring 91 and the rotary shaft 95 are assembled in a state of “tight fit”, whereas The outer ring 92 and the housing 97 are often assembled in a “clear fit” state. Therefore, creep (slip in the circumferential direction of the outer ring 92 with respect to the housing 97) is likely to occur between the outer ring 92 and the housing 97 when the rotary shaft 95 is rotating.

  Therefore, a rolling bearing in which a groove (annular groove) 93 for suppressing the occurrence of creep is formed on the outer peripheral surface 92b of the outer ring 92 has been proposed (see Patent Document 1). According to this rolling bearing 90, it is possible to suppress creep that is likely to occur when a large load in the radial direction (radial direction) is applied. The creep that is likely to occur when such a load is applied is a creep in which the outer ring 92 slowly slides in the same direction as the bearing rotation direction.

JP 2006-322579 A

  The mechanism for suppressing the creep by forming the annular groove 93 on the outer peripheral surface 92b of the outer ring 92 is considered as follows. That is, when a large radial load is applied to the rolling bearing 90, the ball 94 as a rolling element receives a high load and passes through the outer ring raceway groove 92a, and is partially elastic on the outer ring outer peripheral side which is directly below the ball. Deform. Since the ball 94 moves along the outer ring raceway groove 92a, the outer ring 92 undergoes pulsation deformation (pulsation displacement). As a result, relative slip occurs due to elastic deformation in the contact region of the outer ring 92 with the housing 97, and creep occurs due to this relative slip. Therefore, by forming the annular groove 93 on the outer peripheral surface 92b of the outer ring 92 with respect to the housing 97 and mainly elastically deforming within the range of the annular groove 93, the occurrence of the relative slip as described above can be suppressed, and the creep is performed. Can be suppressed.

  However, as described above, the ball 94 receives a high load and passes through the outer ring raceway groove 92a, and the outer ring 92 is partially elastically deformed on the outer ring outer peripheral side, which is directly below, but the annular ring 93 is formed in the outer ring 92. As a result, a large stress exceeding the allowable stress, for example, is generated at the groove bottom portion (particularly near the center of the groove bottom portion) 93a of the annular groove 93.

  Therefore, an object of the present invention is to reduce stress generated in an annular groove formed on a fixed ring of a rolling bearing for suppressing creep.

  The present invention comprises an inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a cage that holds the plurality of rolling elements, the inner ring and the outer ring, A rolling bearing in which one of them is a rotating ring and the other is a fixed ring, and an annular groove for suppressing creep is formed on a mating surface with a mating member to which the fixed ring is attached, The annular groove has a first groove in the center in the axial direction, and a second groove formed continuously with the first groove on both sides in the axial direction of the first groove and shallower than the first groove. When the fixed ring is elastically deformed by a radial load received from the rolling element, the second groove has a groove depth at which a part of the second groove on the first groove side can come into contact with the mating member. Have.

  According to this rolling bearing, when the fixed ring is elastically deformed by the radial load received from the rolling element, the part of the second groove comes into contact with the mating member, and the stress generated in the annular groove of the fixed ring is reduced. It becomes possible.

Further, the part of the second groove is either in a state in contact with the counterpart member or in a non-contact state with the counterpart member according to the magnitude of the radial load acting on the fixed ring. It is preferable to be in the state.
In this case, when the radial load acting on the fixed ring is relatively large and the distortion of the fixed ring becomes large, as described above, the part of the second groove comes into contact with the mating member. Can be reduced. When the radial load acting on the fixed ring is relatively small and the distortion of the fixed ring is small, the part of the second groove is not in contact with the mating member. The groove width of the annular groove containing can be increased, and the effect of suppressing creep can be improved. That is, the groove width of the annular groove is widened to improve the effect of suppressing creep, and the stress generated in the annular groove can be reduced even when the radial load increases.

  Further, even if the radial load acting on the fixed ring is increased and the part of the second groove is in contact with the mating member, the first groove is the mating member from the viewpoint of suppressing creep of the fixed ring. It is preferable that the member is non-contact. For this reason, it is preferable that the first groove has a groove depth incapable of contacting the mating member.

In addition, an intersection where the bottom surface of the second groove intersects with the side surface of the first groove is the part of the second groove that can come into contact with the mating member, and the intersection is a bearing center line It is preferable that the cross section including a convex round shape.
According to this configuration, even if the intersecting portion contacts the mating member, it is possible to suppress the contact surface pressure at the mating member from being locally increased.

Alternatively, the intersection where the bottom surface of the second groove intersects the side surface of the first groove is the part of the second groove that can come into contact with the mating member, and the intersection is the first It is preferable to have an inclined shape in which the groove depth becomes deeper toward the groove side.
According to this configuration, even if the intersecting portion contacts the mating member, it is possible to suppress the contact surface pressure at the mating member from being locally increased.

  According to the present invention, the occurrence of creep can be suppressed by forming the annular groove in the fixed ring, and the stress generated in the annular groove can be reduced.

It is a longitudinal cross-sectional view which shows one Embodiment of the rotating apparatus containing the rolling bearing of this invention. It is sectional drawing of a rolling bearing. It is an expanded sectional view of an annular groove and its circumference. It is an expanded sectional view of an annular groove and its circumference. It is explanatory drawing for demonstrating the function of an annular groove. It is explanatory drawing of an annular groove. It is an expanded sectional view explaining the modification of a part of the 2nd groove | channel which contacts a housing. It is an expanded sectional view explaining the modification of an annular groove. It is an expanded sectional view explaining the modification of an annular groove. It is sectional drawing which shows the other form of a rolling bearing. It is sectional drawing explaining the conventional rolling bearing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of a rotating device 1 including a rolling bearing 7 of the present invention. The rotating device 1 includes a housing 2 and a rotating shaft 4, and the rotating shaft 4 is rotatably supported by the housing 2 by a pair of rolling bearings 7 and 7. The rotating shaft 4 is interposed between the small-diameter shaft portions 4a and 4a to which the rolling bearings 7 and 7 are attached and the rolling bearings 7 and 7 (inner rings 11 and 11), and has a larger outer diameter than the small-diameter shaft portion 4a. And a radial shaft portion 4b.

  Annular portions 5a and 5b are provided on both axial sides of the inner peripheral surface 3 of the housing 2 (hereinafter also referred to as the housing inner peripheral surface 3). The rolling bearings 7 and 7 are preload application type bearings for a motor, and the rolling bearings 7 and 7 are in a state where an axial load (preload) is applied.

  The rolling bearing 7 on one side in the axial direction (right side in FIG. 1) and the rolling bearing 7 on the other side in the axial direction (left side in FIG. 1) have the same configuration. In the following, a detailed configuration will be described with the rolling bearing 7 on one axial side (right side in FIG. 1) as a representative.

  FIG. 2 is a cross-sectional view of the rolling bearing 7. The rolling bearing 7 includes an inner ring 11 that is externally fitted to the rotary shaft 4, an outer ring 12 that is attached to the inner peripheral surface 3 of the housing, and a plurality of rollers that are interposed between the inner ring 11 and the outer ring 12. Rolling elements and an annular retainer 14 for holding the rolling elements. The rolling element of this embodiment is a ball 13, and the rolling bearing 7 shown in FIG. 2 is a deep groove ball bearing. As described above, one axial load acts on the rolling bearing 7.

In the present embodiment, the inner ring 11 and the rotating shaft 4 are assembled in an “tight fit” state, and the inner ring 11 is fitted in close contact with the rotating shaft 4 and can rotate integrally with the rotating shaft 4. On the other hand, the outer ring 12 is attached to the housing 2 in a fixed state, and the outer ring 12 is assembled to the inner peripheral surface 3 of the housing in a “clearance fit” state.
Therefore, creep (slip in the circumferential direction of the outer ring 12 with respect to the housing 2) may occur between the outer ring 12 and the housing 2 when the rotary shaft 4 is rotating together with the inner ring 11. The creep will be described later.

  An inner ring raceway groove (track surface) 11 a on which the balls 13 roll is provided on the outer peripheral surface of the inner ring 11, and an outer ring raceway groove (track surface) on which the balls 13 roll on the inner peripheral surface of the outer ring 12. 12a is provided. The plurality of balls 13 are provided in the annular space 15 between the inner ring 11 and the outer ring 12, and when the rolling bearing 7 rotates (when the inner ring 11 rotates), these balls 13 are held by the cage 14. In this state, the inner ring raceway groove 11a and the outer ring raceway groove 12a roll.

  The cage 14 can hold a plurality of balls 13 at predetermined intervals (equal intervals) along the circumferential direction. For this purpose, the cage 14 has pockets 18 for receiving the balls 13 around it. A plurality are formed along the direction. The cage 14 of the present embodiment includes an annular portion 14a provided on one axial side of the ball 13 and a plurality of column portions 14b extending from the annular portion 14a to the other axial side. Have. A pocket 18 is formed between the pair of column portions 14b, 14b adjacent to each other in the circumferential direction on the other axial side of the annular portion 14a (left side in FIG. 2). Note that the cage 14 may have other forms, for example, a configuration having an annular portion on the other side in the axial direction.

  In the rolling bearing 7 of the present embodiment, an outer ring 12 that is a fixed ring is attached to the housing 2 (a mating member), and an outer peripheral surface of the outer ring 12 is fitted with a fitting surface 22 with respect to the housing 2 (inner peripheral surface 3). It has become. As shown in FIG. 2, an annular groove 32 is formed in the fitting surface 22. The annular groove 32 includes an annular concave groove that is continuous in the circumferential direction, and the cross-sectional shape thereof is the same without changing along the circumferential direction. As will be described later, the annular groove 32 includes a first groove 41 provided at the center in the axial direction and second grooves 42 and 42 on both sides in the axial direction of the first groove 41. The radially outer position of the contact point P of the ball 13 with respect to the outer ring raceway groove 12a coincides with the axial central portion of the first groove 41, and the annular groove 32 is formed in the axial central portion of the fitting surface 22. Is formed.

  In each of the drawings showing the annular groove 32, the shape of the annular groove 32 is described deeply for ease of explanation. However, the actual depth of the annular groove 32 is extremely small compared to the thickness of the outer ring 12, and The depth of 32 can be less than 1 mm, for example.

Here, the creep that occurs between the housing 2 and the outer ring 12 will be described. The following three possible creeps may occur in the rolling bearing 7. In the present embodiment, the bearing rotation direction described below is the rotation direction of the inner ring 11 that is a rotating wheel.
First creep: creep in which the outer ring 12 slips slowly in the same direction as the bearing rotation direction. Second creep: creep in which the outer ring 12 slides in the same direction as the bearing rotation direction. Third creep: reverse to the bearing rotation direction. Creep that outer ring 12 slides in direction

  The first creep is likely to occur when a large load in the radial direction (radial direction) is acting on the rolling bearing 7 and is considered to be generated by the following mechanism. That is, when a large radial load is applied to the rolling bearing 7, the ball 13 receives a high load and passes through the outer ring raceway groove 12 a, and at this time, the outer peripheral side of the outer ring directly below the ball 13 is partially elastic. Deform. Since the ball 13 moves along the outer ring raceway groove 12a, the outer ring 12 undergoes pulsation deformation (pulsation displacement). Thereby, it is considered that relative slip occurs due to elastic deformation in the contact region of the outer ring 12 with the housing 2, and the first creep is generated by this relative slip.

  The second creep has the same moving direction (sliding direction) as the first creep and the outer ring 12, but is likely to occur when the rolling bearing 7 is unloaded in the radial direction. That is, when there is no load in the radial direction, it is considered that the outer ring 12 is rotated by the rotation of the inner ring 11, thereby generating a second creep.

  In the third creep, the moving direction (sliding direction) of the outer ring 12 is opposite to that of the first and second creeps. This is considered to be caused by swinging along 3.

  In the rolling bearing 7 of the present embodiment, the annular groove 32 is formed on the fitting surface 22 of the outer ring 12 and radially outside the outer ring raceway groove 12a in order to suppress the first creep. . The annular groove 32 shown in FIG. 2 has a groove width X0 larger than the axial width Y of the outer ring raceway groove 12a, but has a groove width X0 less than or equal to the axial width Y of the outer ring raceway groove 12a. Also good.

By forming the annular groove 32 in the fitting surface 22 of the outer ring 12 with respect to the housing 2 in this way, the occurrence of relative slip due to elastic deformation as described in the first creep generation mechanism is suppressed. It is possible to suppress the first creep.
That is, when a large radial load is applied to the rolling bearing 7, the radially outer region of the outer ring raceway groove 12a of the outer ring 12 is elastically deformed (expanded) radially outward. By forming the annular groove 32, elastic deformation (expansion) can be caused mainly in the range of the annular groove 32. For this reason, the range in which the elastically deformed portion and the housing inner peripheral surface 3 are in direct contact can be reduced, and the elastic deformation is not (almost) transmitted to the housing 2 which is the counterpart member, so The occurrence of the first creep at is suppressed. As described above, the annular groove 32 becomes a first creep suppressing groove (escape groove).

  Since such an annular groove 32 is provided, the outer ring 12 has cylindrical portions 36 and 37 on both sides in the axial direction of the annular groove 32. The outer peripheral surfaces 36a and 37a of the cylindrical portions 36 and 37 are cylindrical surfaces centered on the bearing center line C0 of the rolling bearing 7 and can be contacted along the housing 2 (inner peripheral surface 3). As shown in FIG. 2, in the cross section including the bearing center line C0, the cross-sectional shapes of the outer peripheral surfaces 36a and 37a of the cylindrical portions 36 and 37 are linear shapes parallel to the bearing center line C0.

  The configuration of the annular groove 32 will be further described. As described above, the annular groove 32 has a central first groove 41 and a pair of second grooves 42 and 42. The first groove 41 and the second grooves 42 and 42 on both sides thereof are continuous. The annular groove 32 of the present embodiment has a bilaterally symmetric shape with respect to the first groove 41 (in FIG. 2). The first groove 41 has a first depth h1. Each of the second grooves 42, 42 has a second depth h 2 that is shallower than the first groove 41. Therefore, the annular groove 32 is a concave groove having a stepped shape with a deep center. The depths h1 and h2 are depth dimensions from the outer peripheral surfaces 36a and 37a.

  The function of the annular groove 32 will be described. As described above, when a radial load is applied to the rolling bearing 7, the outer ring 12 is elastically deformed by a radial load that is received from the balls 13 and directed radially outward. As shown in FIG. 3, when the outer ring 12 is elastically deformed by a relatively large radial load, a part 43 of the second groove 42 on the first groove 41 side comes into contact with the housing 2 (inner peripheral surface 3). That is, the second groove 42 has a groove depth (h2) at which the part 43 can come into contact with the housing 2.

  On the other hand, the first groove 41 has a relatively large radial load, that is, even when a large radial load is applied to the outer ring 12 so that the portion 43 contacts the housing 2. As shown, the housing 2 (inner peripheral surface 3) cannot be contacted. That is, the first groove 41 has a groove depth (h1) that is impossible to contact the housing 2.

  In the present embodiment, the depth h2 of the second groove 42 is also set as follows. That is, when a radial load is applied to the rolling bearing 7, the outer ring 12 is elastically deformed. However, as shown in FIG. 3, when the amount of strain due to this elastic deformation increases, the portion 43 of the second groove 42 is formed in the housing 2. As shown in FIG. 4, the depth h <b> 2 of the second groove 42 is set so that the portion 43 of the second groove 42 does not contact the housing 2 when the strain amount is small. Thus, in the present embodiment, the part 43 of the second groove 42 is in contact with the housing 2 (see FIG. 3) according to the magnitude of the radial load acting on the outer ring 12, and the housing 2 It can be in any one of a non-contact state (see FIG. 4).

  As described above, when a relatively large radial load is applied (the amount of strain increases), for example, the rotating device 1 (see FIG. 1) is rapidly moved from a state where it is stopped or rotating at a low speed. The case where a high torque acts on the rotating shaft 4 to increase the rotational speed is included. On the other hand, when a relatively small radial load is applied (the amount of strain is reduced), for example, a case where a low torque is applied to the rotating shaft 4 during steady operation is included.

Here, the function of creep suppression by the annular groove 32 will be further described. As the groove width X0 (see FIG. 2) is larger, the first creep suppressing action of the annular groove 32 is increased. The reason for this is as follows. That is, when the outer ring 12 is elastically deformed radially outward by a radial load, the strain amount at the outer peripheral part of the outer ring 12 is a central part close to the contact point P between the ball 13 and the outer ring raceway groove 12a as shown in FIG. The amount of strain increases at Q1, and the amount of strain decreases toward the two axial sides Q2, Q3. In FIG. 5, the amount of strain in the outer ring outer peripheral portion is shown in the upper region. Further, in FIG. 5, the annular groove 32 is described as a one-stage groove for ease of explanation.
Therefore, in order to suppress the first creep as described above, it is only necessary to form the annular groove 32 as much as possible in a region where the amount of strain increases. For this reason, the annular groove 32-1 (groove shown by a broken line in FIG. Compared with the case of forming the width X0-1), the housing 2 shows a region where the strain amount of the outer ring 12 is larger when the annular groove 32-2 (groove width X0-2) shown by the solid line in FIG. (See FIG. 2). Thereby, the 1st creep resulting from the pulsation deformation | transformation (pulsation displacement) of the outer ring | wheel 12 is suppressed. From the above, the effect of the first creep suppression increases as the groove width X0 of the annular groove 32 increases.

  Therefore, in the rolling bearing 7 shown in FIG. 2, the second grooves 42 and 42 are formed on both axial sides of the first groove 41 to increase the groove width X0 of the annular groove 32. Thereby, the effect | action of the 1st creep suppression by this annular groove 32 is heightened.

  However, as the groove width X0 of the annular groove 32 increases, the stress generated in the annular groove 32 increases. This is apparent when the outer ring 12 is considered (modeled) as a two-point support beam B in which a load acts on the center, as shown in FIG. That is, the end portions 36 b and 37 b of the cylindrical portions 36 and 37 on both sides of the annular groove 32 correspond to the fulcrum of the beam B. When the concentrated load F (from the ball 13) acts on the center between these fulcrums (36b, 37b), the greater the distance L1 between the fulcrums (36b, 37b), the higher the stress at this beam B (especially the center). . That is, the greater the groove width X0 of the annular groove 32, the higher the stress at the center of the outer ring 12.

  As described above, in the outer ring 12, the stress is increased at the central portion of the annular groove 32, that is, the central portion of the first groove 41 and the top portion 41 a that is elastically deformed most convexly. In particular, this stress increases when a relatively large radial load as described above acts (the amount of strain increases).

  Therefore, in the rolling bearing 7 shown in FIG. 2, when a relatively large radial load acts and the outer ring 12 is elastically deformed by the radial load received from the balls 13, as shown in FIG. A part 43 on the first groove 41 side can come into contact with the housing 2. In this contacted state, a part of the radial load is transmitted from the part 43 of the second groove 42 to the housing 2. That is, when the outer ring 12 is considered as the two-point support beam B as described with reference to FIG. 6, the pair of the portions 43 and 43 included in the annular groove 32 come into contact with the housing 2. 43 becomes a fulcrum of the beam B, and the distance L2 between these fulcrums 43 and 43 becomes small (L2 <L1), so that the stress generated at the center of the annular groove 32 (the center of the beam B) can be reduced. It becomes possible.

Further, in this rolling bearing 7, when the radial load acting on the outer ring 12 is relatively small and the strain of the outer ring 12 is small, as described above (see FIG. 4), a part 43 of the second grooves 42, 42, 43 is in a non-contact state with the housing 2, whereby the groove width X 0 of the annular groove 32 including the first groove 41 and the second grooves 42, 42 can be increased. As a result, the effect of suppressing creep can be improved.
That is, according to the rolling bearing 7 of the present embodiment, the groove width X0 of the annular groove 32 is made as wide as possible to improve the effect of suppressing creep, and even if the radial load increases, the second groove 42 is increased. The part 43 of the contact with the housing 2 makes it possible to reduce the stress generated in the annular groove 32.

  Even when the radial load acting on the outer ring 12 is increased and a portion 43 of the second groove 42 is in contact with the housing 2, the first groove 41 is not in contact with the housing 2. It becomes possible to have an effect of suppressing creep of the outer ring 12.

  Further, as shown in FIG. 3, a part 43 of the second groove 42 may come into contact with the housing 2. Therefore, if this part 43 strongly presses the housing 2, a high surface pressure may be generated in the housing 2. When the surface pressure in the housing 2 is increased, the first creep is suppressed by the annular groove 32. However, if even a slight creep occurs (or if a creep due to other factors occurs), the housing 2 is localized. May wear out. Therefore, a portion 43 of the second groove 42 that comes into contact with the housing 2 has a convex round shape as shown in FIG.

  This round shape will be specifically described. An intersecting portion 47 where the bottom surface 45 of the second groove 42 and the side surface 46 of the first groove 41 intersect becomes a part 43 of the second groove 42 that can come into contact with the housing 2. Therefore, the intersecting portion 47 has a convex round shape. Thus, since the crossing portion 47 has a convex round shape in a cross section including the bearing center line C0 (see FIG. 2), the crossing portion 47 (part 43 of the second groove 42) is a housing. Even if it contacts 2, it becomes possible to suppress that the contact surface pressure in the housing 2 becomes high locally.

  FIG. 7 is an enlarged cross-sectional view illustrating a modified example of a part 43 of the second groove 42 that contacts the housing 2. In the form shown in FIG. 7, as in the form shown in FIG. 3, the intersecting portion 47 where the bottom surface 45 of the second groove 42 and the side face 46 of the first groove 41 intersect with each other can be brought into contact with the housing 2. It becomes a part 43 of 42. 7 has an inclined shape (taper shape) in which the groove depth becomes deeper toward the first groove 41 side. According to this configuration, even when the intersecting portion 47 contacts the housing 2, it is possible to suppress the contact surface pressure in the housing 2 from being locally increased.

  FIG. 8 is an enlarged cross-sectional view for explaining a modification of the annular groove 32. The annular groove 32 includes the first groove 41 and the pair of second grooves 42 and 42, and is the same as the annular groove 32 of each embodiment. The annular groove 32 shown in FIG. 8 further includes inclined groove portions 48 and 48 formed on both sides in the axial direction of the second groove 42. Each of the inclined groove portions 48, 48 is formed shallower than the second groove 42, and has an inclined shape that gradually becomes deeper toward the second groove 42 side. And the shape (inclination angle (theta)) of these inclination groove parts 48 and 48 is set as follows.

That is, when a radial load is applied to the rolling bearing 7, the outer ring 12 is elastically deformed so as to bulge radially outward. At this time, as shown in FIG. It has a shape that comes into contact with the housing 2 by the surface. In the state shown in FIG. 9, the portion 43 of the second groove 42 is not in contact with the housing 2, but the radial load is further increased and the portion 43 of the second groove 42 is in contact with the housing 2. It may be in the state. On the other hand, when the radial load is smaller than the state shown in FIG. 9, the inclined groove portions 48, 48 have a shape that does not contact the housing 2 as shown in FIG. 8.
Thus, in the form shown in FIG. 8, each of the inclined groove portions 48, 48 is in a non-contact state with the housing 2 (see FIG. 8) according to the magnitude of the radial load acting on the outer ring 12, and the housing 2 (see FIG. 9).

  According to the annular groove 32 shown in FIG. 8, when the radial load acting on the outer ring 12 is relatively large and the distortion of the outer ring 12 is increased, at least a part of the inclined groove portion 48 is at an angle with respect to the housing 2. Therefore, the contact surface pressure in the housing 2 can be prevented from being locally increased. When the radial load acting on the outer ring 12 is relatively small and the distortion of the outer ring 12 is small, the inclined groove portions 48 and 48 are not in contact with the housing 2. Thereby, the annular groove 32 becomes a structure containing the 1st groove | channel 41, the 2nd groove | channel 42, and the inclination groove parts 48 and 48, The groove width X0 can be enlarged, and the effect of creep suppression can be improved.

  Moreover, in each said form, although the groove width (axial direction dimension) of the 1st groove | channel 41 may be made larger than the sum of the groove width of a pair of 2nd grooves 42 and 42, it is preferable to make small. That is, it is preferable to reduce the groove width of the first groove 41. Thereby, it is easy to make the 1st groove | channel 41 non-contact with respect to the housing 2, the effect of creep suppression can be ensured, and also the distance L2 between the fulcrums 43 and 43 shown in FIG. The effect of reducing the stress generated in the first groove 41 can be further enhanced.

In the embodiment (see FIG. 1), the inner ring 11 is a rotating wheel that rotates integrally with a mating member (rotating shaft 4) to which the inner ring 11 is attached, and the outer ring 12 is attached to the outer ring 12. This is a fixed ring fixed (but creeped) to the mating member (housing 2).
However, in the present invention, one of the inner ring 11 and the outer ring 12 may be a rotating ring and the other may be a fixed ring, and is attached to a shaft 54 as shown in FIG. The inner ring 11 may be a fixed ring, and the outer ring 12 may be a rotating wheel that rotates together with the housing 55. In this case, the inner ring 11 and the shaft 54 are in a state of clearance fit, and the inner ring 11 creeps with respect to the shaft 54, so that the fitting surface (inner peripheral surface) of the inner ring 11 with respect to the shaft 54 which is the counterpart member. An annular groove 50 is formed in 21 (similar to the embodiment of FIG. 2). The annular groove 50 includes a first groove 51 in the center in the axial direction and second grooves 52 formed continuously with the first groove 51 on both sides in the axial direction of the first groove 51. Yes. The second groove 52 is shallower than the first groove 51. When the inner ring 11 is elastically deformed radially inward by the radial load received from the ball 13, the groove depth at which a part 53 of the second groove 52 on the first groove 51 side can come into contact with the shaft 54 is increased to the second depth. The groove 52 has. Note that each configuration relating to the annular groove 32 of each of the forms shown in FIG.

The embodiments disclosed above are illustrative in all respects and not restrictive. That is, the rolling bearing of the present invention is not limited to the illustrated form, but may be of another form within the scope of the present invention.
In FIG. 1, the rolling bearing 7 has been described as a preload imparting type bearing for a motor. However, the rolling bearing 7 may be other than for a motor, and the rolling bearing of the present invention is applicable to a rotating device in which creep is an issue.
In addition to the deep groove ball bearing, the rolling bearing may be an angular ball bearing, and the rolling element may be other than a ball, and may be a cylindrical roller or a tapered roller.

2: Housing (mating member) 7: Rolling bearing 11: Inner ring 12: Outer ring 13: Ball (rolling element) 14: Cage 21: Inner peripheral surface (fitting surface) of inner ring 22: Outer peripheral surface (fitting surface) of outer ring )
32: Annular groove 41: First groove 42: Second groove 43: Part 45: Bottom surface 46: Side surface 47: Intersection 50: Annular groove 51: First groove 52: Second groove 54: Shaft (mating member)

Claims (5)

An inner ring, an outer ring, a plurality of rolling elements interposed between the inner ring and the outer ring, and a cage for holding the plurality of rolling elements, and one of the inner ring and the outer ring A rolling bearing in which is a rotating wheel and the other is a fixed ring,
An annular groove for suppressing creep is formed on the mating surface with the mating member to which the fixed ring is attached,
The annular groove has a first groove in the center in the axial direction, and a second groove formed continuously with the first groove on both sides in the axial direction of the first groove and shallower than the first groove,
The second groove has a groove depth at which a part of the second groove on the first groove side can come into contact with the mating member when the fixed ring is elastically deformed by a radial load received from the rolling element. Has a rolling bearing.   The part of the second groove is in one of a state in contact with the mating member and a state in non-contact with the mating member according to the magnitude of the radial load acting on the fixed ring. The rolling bearing according to claim 1, wherein   3. The rolling bearing according to claim 1, wherein the first groove has a groove depth incapable of contacting the mating member. The intersecting portion where the bottom surface of the second groove and the side surface of the first groove intersect is the part of the second groove that can come into contact with the mating member,
The rolling bearing according to any one of claims 1 to 3, wherein the intersecting portion has a convex round shape in a cross section including a bearing center line. The intersecting portion where the bottom surface of the second groove and the side surface of the first groove intersect is the part of the second groove that can come into contact with the mating member,
The rolling bearing according to any one of claims 1 to 3, wherein the intersecting portion has an inclined shape in which the groove depth becomes deeper toward the first groove side.

Images