JP2022009464A - Single-row deep groove ball bearing and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single-row deep groove ball bearing capable of suppressing a falling speed of an inner ring falling from an elevator conveyor, to prevent damage of the inner ring, and a manufacturing method thereof.

SOLUTION: An inner ring 12 has an axially asymmetric structure where the shape of one end part in an axis direction is different from that of the other end part in the axis direction with an inner ring raceway groove 12a held therebetween. At the other end part in the axis direction of the inner ring 12, a first small-diameter step part 12f is provided. At an outer peripheral edge of one shoulder part 12b out of a pair of shoulder parts 12b adjacent to the inner ring raceway groove 12a of the inner ring 12, an inner ring side chamfer part 12i is provided, wherein the inner ring side chamfer part is larger than a chamfer part 12e provided on an outer peripheral edge of the other shoulder part 12b.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a single row deep groove ball bearing in which an inner ring is conveyed by an elevator conveyor at the time of manufacturing, for example, a semi-floating rear wheel axle ball bearing, and a method for manufacturing the same.

The semi-floating wheel support device has a simple structure and is inexpensive, and the ball bearings for semi-floating rear wheel axles (hereinafter also referred to as "ball bearings") can be easily replaced. Widely installed in cars and small commercial vehicles (vans and trucks). In this wheel support device, a ball bearing is press-fitted and fixed to the outer peripheral surface of an axle (axle shaft) provided with a wheel mounting portion at its end, and the axle shaft is rotatably supported via the ball bearing.

As this type of ball bearing, it is known that a protruding portion protruding in the axial direction is formed in the inner ring, and the axial dimension (width) of the inner ring is provided longer than the axial dimension of the outer ring (for example, Patent Document 1). reference). That is, the inner ring of this type of ball bearing is provided in an axially asymmetrical structure with a protruding portion formed and the inner ring raceway groove interposed therebetween.

Japanese Unexamined Patent Publication No. 2002-013539

When grinding or super-finishing the inner ring raceway groove of the inner ring having an asymmetric structure as described above, the inner ring raceway groove is located at a position deviated from the center of the entire width of the inner ring, so that the inner ring is oriented in a predetermined direction during the manufacturing process. Need to be aligned with. Therefore, in order to align the directions of the inner rings of the asymmetric structure, an elevator conveyor is used in which the center of gravity of the inner rings of the asymmetric structure is biased to one side with respect to the center in the axial direction and is arranged diagonally with respect to the gravity direction. This elevator conveyor aligns the directions of a large number of inner rings housed in the hopper while transporting them one by one or one or more from the bottom to the top.

Here, with reference to FIGS. 7 and 8, a conventional example of transporting an inner ring having an asymmetric structure by an elevator conveyor will be described. FIG. 7 is a cross-sectional view illustrating a state in which an inner ring of a conventional ball bearing is engaged with a claw portion of an elevator conveyor at a protruding portion thereof and conveyed. FIG. 8 is a cross-sectional view illustrating a state in which an inner ring of a conventional ball bearing is engaged with a claw portion of an elevator conveyor at an end portion opposite to the protruding portion in the axial direction and conveyed.

As shown in FIGS. 7 and 8, the inner ring 52 has an axially asymmetric structure with the inner ring raceway groove 52a interposed therebetween, and has an axial axis at one end in the axial direction (left end in FIG. 7, right end in FIG. 8). It has a protruding portion 52c that protrudes outward in the direction. Further, a small diameter step portion 52d is formed over the entire circumference on the outer peripheral surface of the other end portion in the axial direction of the inner ring 52 (the right end portion in FIG. 7 and the left end portion in FIG. 8). Further, the inner ring 52 has a pair of shoulder portions 52b adjacent to the inner ring raceway groove 52a on the outer peripheral portion thereof, and one of the pair of shoulder portions 52b constitutes the protruding portion 52c. Further, the outer peripheral surface of the protruding portion 52c and the outer peripheral surface of the shoulder portion 52b on the small diameter step portion 52d side are each formed into a cylindrical surface having a uniform diameter.

The elevator conveyor 60 includes a belt 61 and a claw portion 62 provided on the surface of the belt 61 for mounting the inner ring 52. The claw portion 62 is formed in a rectangular shape in a cross-sectional view in the direction of gravity and in a linear shape along the width direction of the belt 61. The elevator conveyor 60 places the outer peripheral surface of the inner ring 52 on the upper surface of the claw portion 62, and conveys the inner ring 52 upward.

Specifically, as shown in FIG. 7, when one end surface of the inner ring 52 on the protruding portion 52c side is located on the belt 61 side, the outer peripheral surface of the protruding portion 52c of the inner ring 52 engages with the upper surface of the claw portion 62. Will be transported. Then, in the transport state shown in FIG. 7, the vertical line L passing through the center of gravity G of the inner ring 52 passes through the range of the upper surface of the claw portion 62 or the range of the belt 61 side (left side of FIG. 7) with respect to the upper surface of the claw portion 62. Therefore, the inner ring 52 is conveyed to the next step without falling from the claw portion 62.

On the other hand, as shown in FIG. 8, when the other end surface of the inner ring 52 on the small diameter step portion 52d side is located on the belt 61 side, the outer peripheral surface of the shoulder portion 52b on the small diameter step portion 52d side of the inner ring 52 is the claw portion 62. It engages with the upper surface and is conveyed. However, in the transport state shown in FIG. 8, since the vertical line L passing through the center of gravity G of the inner ring 52 is located on the side away from the belt 61 with respect to the claw portion 62, the engagement portion between the inner ring 52 and the claw portion 62 is centered. The inner ring 52 rotates in the direction away from the belt 61 (direction of arrow B in FIG. 8), and the inner ring 52 falls from the claw portion 62 during transportation. Therefore, when the other end surface of the inner ring 52 on the small diameter step portion 52d side is located on the belt 61 side, the inner ring 52 is not conveyed to the next step.

When the inner ring 52 rotates from the belt 61 and falls, the fall distance becomes large and an indentation is formed on the inner ring 52, and when the drop is severe, a microcrack occurs at the bottom of the indentation and the inner ring 52 is delayed. It could cause damage such as destruction.

By the way, in the inner ring of the ball bearing of Patent Document 1 described above, since a small diameter step portion is formed on the outer peripheral surface of the protruding portion and a large chamfered portion is formed on the inner peripheral surface of the protruding portion, the inner ring protrudes. A large cutout is formed in the part. Therefore, the movement of the center of gravity from the axial center of the inner ring between the case where the end surface on the protruding portion side of the inner ring is located on the belt side and the case where the end surface on the side away from the protruding portion of the inner ring is located on the belt side. Is reduced. Therefore, in the case of the inner ring of the ball bearing of Patent Document 1 described above, it is difficult to apply the method of aligning the directions of the inner rings shown in FIGS. 7 and 8.

The present invention has been made in view of the above-mentioned problems, and an object thereof is a single-row deep groove ball bearing capable of suppressing the falling speed of the inner ring falling from the elevator conveyor and preventing damage to the inner ring. The purpose is to provide a manufacturing method.

The above object of the present invention is achieved by the following configuration.
(1) An outer ring having an outer ring raceway groove formed on the inner peripheral surface, and a plurality of balls rotatably provided between the inner ring having an inner ring raceway groove formed on the outer peripheral surface, the outer ring raceway groove, and the inner ring raceway groove. A single-row deep groove ball bearing comprising, the inner ring has an axially asymmetric structure in which the shapes of one end in the axial direction and the other end in the axial direction are different across the inner ring raceway groove, and the other end in the axial direction of the inner ring. A first small-diameter step portion is provided in the portion, and the outer peripheral edge of the other shoulder portion of the pair of shoulder portions adjacent to the inner ring raceway groove of the inner ring is larger than the chamfered portion provided on the outer peripheral edge of one shoulder portion. Single row deep groove ball bearings characterized by a large inner ring chamfer.
(2) The simple dimension according to (1), wherein the axial dimension from the inner ring raceway groove to the axial end surface of the inner ring is larger than the axial dimension from the inner ring raceway groove to the axial end surface of the inner ring. Row deep groove ball bearings.
(3) The intersection angle between the straight line passing through the inner ring side surface portion and the center of gravity of the inner ring and the central axis of the inner ring is 55 ° to 75 °.
The single row deep groove ball bearing according to (1) or (2), which is set in the range of.
(4) The method for manufacturing a single-row deep groove ball bearing according to any one of (1) to (3), wherein the inner ring is moved from the bottom to the top by an elevator conveyor arranged diagonally with respect to the direction of gravity. The elevator conveyor is conveyed and includes a belt and a claw portion provided on the surface of the belt for mounting an inner ring, and the claw portion is formed in a rectangular shape in a cross-sectional view in the direction of gravity, and the upper surface and the front surface surface of the claw portion are formed. A claw side bearing portion is provided on the edge portion between the bearing and the outer peripheral edge of the other shoulder portion of the pair of shoulder portions adjacent to the inner ring raceway groove of the inner ring. An inner ring side surface larger than the chamfered portion is provided, and when the inner ring is conveyed by the claw portion of the elevator conveyor, the inner ring side surface portion is located so as to face the claw side surface capture portion, and the center of gravity of the inner ring. A method for manufacturing a single-row deep groove ball bearing, which is characterized by being located on a vertical line passing through.
(5) A second small-diameter step portion is provided at one end in the axial direction of the inner ring, and the second small-diameter step portion is provided by grinding at the same time as the inner ring raceway groove, and is a horizontal plane orthogonal to the transport direction and the gravity direction of the elevator conveyor. The method for manufacturing a single-row deep groove ball bearing according to (4), wherein the angle of intersection with the bearing is set to be equal to or greater than the angle of intersection between the straight line passing through the side surface portion of the inner ring and the center of gravity of the inner ring and the central axis of the inner ring.

According to the present invention, the inner ring has an axially asymmetric structure in which the shapes of one end in the axial direction and the other end in the axial direction are different across the inner ring raceway groove, and the first small diameter step is formed at the other end in the axial direction of the inner ring. A portion is provided, and the outer peripheral edge of the other shoulder portion of the pair of shoulder portions adjacent to the inner ring raceway groove of the inner ring has an inner ring side surface portion larger than the chamfered portion provided on the outer peripheral edge of one shoulder portion. Therefore, when the inner ring is conveyed by the claw portion of the elevator conveyor, the inner ring side surface portion is located so as to face the claw side surface portion of the claw portion and is located on a vertical line passing through the center of gravity of the inner ring. For this reason, the inner ring side surface portion of the inner ring slides down the claw side surface portion of the claw portion and slides down along the belt without rotating the inner ring. Therefore, the falling speed of the inner ring is suppressed to prevent damage to the inner ring. Can be done.

It is sectional drawing explaining 1st Embodiment of the single row deep groove ball bearing which concerns on this invention. FIG. 3 is a cross-sectional view illustrating a state in which the inner ring shown in FIG. 1 is engaged with a claw portion at one shoulder portion and conveyed. FIG. 3 is a cross-sectional view illustrating a state in which the inner ring shown in FIG. 1 is engaged with a claw portion at the other shoulder portion and conveyed. It is sectional drawing explaining the modification of the 1st Embodiment of the single row deep groove ball bearing which concerns on this invention. It is sectional drawing explaining the 2nd Embodiment of the single row deep groove ball bearing which concerns on this invention. FIG. 5 is a cross-sectional view illustrating a state in which the inner ring shown in FIG. 5 is engaged with a claw portion at one shoulder portion and conveyed. It is sectional drawing explaining the state which engages and conveys the inner ring of the conventional ball bearing with the claw part of an elevator conveyor by the protruding part. It is sectional drawing explaining the state which carries out the inner ring of the conventional ball bearing by engaging with the claw part of an elevator conveyor at the end part opposite to the protruding part.

Hereinafter, each embodiment of the single-row deep groove ball bearing according to the present invention will be described in detail with reference to the drawings. A single row deep groove ball bearing (hereinafter also referred to as "ball bearing") is a rolling bearing mounted on a semi-floating wheel support device, and is used to rotatably support the rear wheels (driving wheels) of the vehicle. Used for. Further, in the semi-floating wheel support device, the axle (axle shaft) is housed in the housing (axle housing) via ball bearings. Then, the ball bearing of the present embodiment is locked to the outer peripheral surface of the axle shaft.

(First Embodiment)
First, a first embodiment of a single-row deep groove ball bearing according to the present invention will be described with reference to FIGS. 1 to 4.

As shown in FIG. 1, the ball bearing (single row deep groove ball bearing) 10 of the present embodiment has an outer ring 11 which is a fixed raceway ring, an inner ring 12 which is a rotary raceway ring, and an outer ring raceway groove 11a and an inner ring of the outer ring 11. A plurality of balls 13 rotatably provided between the inner ring raceway grooves 12a of the twelve, a cage 14 for holding the plurality of balls 13 at substantially equal intervals in the circumferential direction, and both ends of the inner peripheral surface of the outer ring 11. The first and second sealing devices 15 and 16 attached to the above are provided. Further, a lubricant (for example, grease) is sealed in the bearing internal space.

The outer ring 11 has an outer ring raceway groove 11a formed at the center of the inner peripheral surface in the axial direction, and has a pair of shoulder portions 11b adjacent to the outer ring raceway groove 11a. The outer ring 11 has substantially the same shape at one end in the axial direction and the other end in the axial direction with the outer ring raceway groove 11a interposed therebetween.

The inner ring 12 has an inner ring raceway groove 12a formed on the outer peripheral surface thereof, and has a pair of shoulder portions 12b adjacent to the inner ring raceway groove 12a. Further, the inner ring 12 has an axially asymmetrical structure in which the shapes of one end in the axial direction and the other end in the axial direction are different across the inner ring raceway groove 12a, and the groove bottom portion of the inner ring raceway groove 12a to the one end surface in the axial direction of the inner ring 12. The axial dimension B1 up to 12c is formed to be larger than the axial dimension B2 from the groove bottom portion of the inner ring raceway groove 12a to the axial end surface 12d of the inner ring 12. Therefore, the axial dimension of the inner ring 12 is configured to be larger than the axial dimension of the outer ring 11, and one end portion of the inner ring 12 in the axial direction protrudes outward in the axial direction from the one end surface of the outer ring 11 in the axial direction. Further, the axial end surface of the inner ring 12 has substantially the same axial position as the axial end surface of the outer ring 11.

Further, on the outer peripheral edge of the shoulder portion 12b on one side in the axial direction (right side in FIG. 1) of the inner ring 12, a tapered or arcuate chamfered portion 12e is formed over the entire circumference. The outer peripheral surfaces of the pair of shoulder portions 12b are formed into cylindrical surfaces having uniform diameters.

Further, on the outer peripheral surface of the other end of the inner ring 12 in the axial direction (left end in FIG. 1), a first small diameter step portion having a bottom surface 12g and a side surface 12h so as to have a smaller diameter than the outer peripheral surface of the shoulder portion 12b. 12f is formed over the entire circumference. The bottom surface 12g of the first small diameter step portion 12f is formed on a tapered surface whose diameter is reduced outward in the axial direction.

Further, the outer peripheral edge of the shoulder portion 12b on the other side in the axial direction of the inner ring 12, that is, between the side surface 12h of the first small diameter step portion 12f and the outer peripheral surface of the shoulder portion 12b on the other side in the axial direction (left side in FIG. 1). A tapered inner ring side surface portion 12i is formed on the edge portion over the entire circumference. That is, the first small diameter step portion 12f is provided at the axial end portion of the inner ring 12 on the side where the inner ring side surface portion 12i is provided. The inner ring side surface chamfer portion 12i is formed to have a larger radial dimension and axial dimension than the chamfer portion 12e of the shoulder portion 12b on one side.

The first sealing device 15 is a seal that is arranged on the outside of the vehicle in the vehicle assembled state and prevents external dust and muddy water from entering the ball bearings, and the radial lip is attached to the shoulder portion 12b on one side of the inner ring 12. The side lip is in sliding contact with the outer peripheral surface and the side lip is in sliding contact with the axial inner surface of the circular ring portion of the slinger 15a having an L-shaped cross section in which the cylindrical portion is fitted to the outer peripheral surface of the shoulder portion 12b on one side of the inner ring 12. The second sealing device 16 is a seal for preventing the differential oil sealed in the axle pipe from washing away the lubricant sealed in the ball bearing, and the radial lip is the first small diameter step portion 12f of the inner ring 12. It is in sliding contact with the bottom surface 12 g.

Next, the manufacturing process of the inner ring 12 described above will be described. The manufacturing process of the inner ring 12 includes a transport process in which the inner ring 12 on which the inner ring side surface portion 12i is formed is conveyed by an elevator conveyor 20 described later, and a raceway groove processing step (grinding) in which the inner ring raceway groove 12a of the conveyed inner ring 12 is machined. Processing process or super-finishing process), and at least includes.

In the transporting process, the inner rings 12 are aligned in a predetermined direction and transported to the track groove processing step. In the raceway groove processing step, the inner ring raceway groove 12a of the inner ring 12 is subjected to grinding or super-finishing. The inner ring 12 has an inner ring side surface step portion 12i, a chamfer portion 12e, and a first small diameter step portion 12f formed in advance by cutting or the like before the transfer process.

Next, the transfer process of the inner ring 12 will be described in detail with reference to FIGS. 2 and 3.

In the transfer step, as shown in FIGS. 2 and 3, the inner ring 12 is conveyed from the bottom to the top by the elevator conveyor 20 arranged diagonally with respect to the gravity direction (vertical direction of FIGS. 2 and 3). That is, the transport direction D of the elevator conveyor 20 is set diagonally with respect to the gravity direction.

The elevator conveyor 20 includes a belt 21 and a claw portion 22 provided on the surface of the belt 21 for mounting the inner ring 12. The claw portion 22 is formed in a rectangular shape in a cross-sectional view in the direction of gravity and in a linear shape along the width direction of the belt 21. A curved claw side surface picking portion 22a is formed on the edge portion between the upper surface and the front side surface of the claw portion 22. The elevator conveyor 20 places the inner ring 12 on the upper surface of the claw portion 22 and conveys the inner ring 12 upward.

Then, as shown in FIG. 2, when the axial end surface 12c of the inner ring 12 is located on the belt 21 side to convey the inner ring 12, the outer peripheral surface of the shoulder portion 12b on one side of the inner ring 12 is the upper surface of the claw portion 22. Engage in. At this time, since the vertical line L passing through the center of gravity G of the inner ring 12 is located in the range of the upper surface of the claw portion 22 or the range on the belt 21 side of the upper surface of the claw portion 22, the inner ring 12 does not fall from the claw portion 22 and is next. Transported to the process. The center of gravity G of the inner ring 12 is located on the central axis (axial direction line passing through the radial center) C of the inner ring 12.

On the other hand, as shown in FIG. 3, when the other end surface 12d in the axial direction of the inner ring 12 is located on the belt 21 side to convey the inner ring 12, the inner ring side surface portion 12i of the inner ring 12 is the claw side surface portion of the claw portion 22. Engage with 22a. At this time, since the inner ring side surface picking portion 12i is located so as to face the claw side surface picking portion 22a and on the vertical line L passing through the center of gravity G of the inner ring 12, the inner ring side surface picking portion 12i of the inner ring 12 is located on the claw side surface. It slides down the take portion 22a (see arrow A in FIG. 3), and the inner ring 12 slides down along the belt 21 without rotating. Therefore, the inner ring 12 falls from the claw portion 22 and is not conveyed to the next step. Further, when the inner ring 12 slides down along the belt 21, the falling speed of the inner ring 12 is suppressed, and damage to the inner ring 12 is prevented.

As described above, according to the single-row deep groove ball bearing 10 and the manufacturing method thereof of the present embodiment, when the inner ring 12 is conveyed by the claw portion 22 of the elevator conveyor 20, the inner ring side surface removing portion 12i receives the claw side surface removing portion 12i. It is located so as to face the portion 22a and is located on the vertical line L passing through the center of gravity G of the inner ring 12. Therefore, the inner ring side surface portion 12i of the inner ring 12 slides down the claw side surface portion 22a of the claw portion 22 and slides down along the belt 21 without rotating the inner ring 12, so that the falling speed of the inner ring 12 is suppressed. It is possible to prevent damage to the inner ring 12.

Further, according to the single row deep groove ball bearing 10 of the present embodiment and the manufacturing method thereof, the bottom surface 12g of the first small diameter step portion 12f of the inner ring 12 is formed on a tapered surface whose diameter is reduced outward in the axial direction. Therefore, when the inner ring side surface picking portion 12i of the inner ring 12 slides down the claw side surface picking portion 22a of the claw portion 22, the bottom surface 12g of the first small diameter step portion 12f does not get caught on the claw portion 22 and does not prevent the inner ring 12 from sliding down. .. Therefore, the inner ring 12 can be slid off along the belt 21 without rotating.

Further, as a modification of the present embodiment, as shown in FIG. 4, the protrusion width of the axial end portion of the inner ring 12 with respect to the axial end surface of the outer ring 11 may be reduced. Further, a second small diameter step portion 12k is formed on the outer peripheral surface of one end portion in the axial direction (right end portion in FIG. 4) of the inner ring 12 over the entire circumference, and the first sealing device 15 is the same as the second sealing device 16. It has a structure. Further, also in this modification, as shown in FIGS. 2 and 3, the inner rings 12 can be aligned in a predetermined direction and conveyed to the next step.

(Second Embodiment)
Next, a second embodiment of the single-row deep groove ball bearing according to the present invention will be described with reference to FIGS. 5 and 6. The same or equivalent parts as those in the first embodiment are designated by the same reference numerals in the drawings, and the description thereof will be omitted or simplified.

In the present embodiment, as shown in FIG. 5, the bottom surface 12n and the side surface of the inner ring 12 so that the outer peripheral surface of the axial end portion (right end portion in FIG. 5) has a smaller diameter than the outer peripheral surface of the shoulder portion 12b. A second small diameter step portion 12m having 12p is formed over the entire circumference. The second small diameter step portion 12m has a larger diameter than the first small diameter step portion 12f at the other end in the axial direction. Further, the bottom surface 12n of the second small diameter step portion 12m is formed on a cylindrical surface having a uniform diameter, and the side surface 12p of the second small diameter step portion 12m is formed on a tapered surface whose diameter is reduced outward in the axial direction. Further, the slinger 15a is fitted to the bottom surface 12n of the second small diameter step portion 12m.

The second small diameter step portion 12m is formed by grinding at the same time as the inner ring raceway groove 12a of the inner ring 12 in the raceway groove processing step of the above-mentioned manufacturing process.

Further, in the present embodiment, the intersection angle α between the straight line E passing through the inner ring side surface portion 12i and the center of gravity G of the inner ring 12 and the central axis C of the inner ring 12 is in the range of 55 ° to 75 °, more preferably 60 ° to 70. Set in the range of °. More specifically, the straight line E is a straight line passing between the inner end in the axial direction and the outer end in the axial direction of the inner ring side surface portion 12i. Therefore, the intersection angle α between the straight line E passing through the axial inner end of the inner ring side surface portion 12i and the center of gravity G of the inner ring 12 and the central axis C of the inner ring 12, and the axial outer end and inner ring 12 of the inner ring side surface portion 12i. Both the intersection angle α between the straight line E passing through the center of gravity G and the central axis C of the inner ring 12 are set in the range of 55 ° to 75 °, more preferably in the range of 60 ° to 70 °. In this embodiment, the intersection angle α is set to 63 ° to 66 °.

Further, in the present embodiment, as shown in FIG. 6, the intersection angle β between the transport direction D of the elevator conveyor 20 and the horizontal plane F orthogonal to the gravity direction (= vertical line L) is the inner ring side surface portion 12i and the inner ring 12. The angle between the straight line E passing through the center of gravity G and the central axis C of the inner ring 12 is set to be equal to or greater than α (β ≧ α). That is, in the present embodiment, the cross angle β is set to 66 ° or more.

Then, when the crossing angle α and the crossing angle β are set as described above and the other end surface 12d in the axial direction of the inner ring 12 is located on the belt 21 side to convey the inner ring 12, the inner ring side surface portion 12i of the inner ring 12 becomes available. It slides down the claw side surface portion 22a (see arrow A in FIG. 6), and the inner ring 12 slides down along the belt 21 without rotating. Therefore, the inner ring 12 falls from the claw portion 22 and is not conveyed to the next step. Further, when the inner ring 12 slides down along the belt 21, the falling speed of the inner ring 12 is suppressed, and damage to the inner ring 12 is prevented.

Further, when the axial end surface 12c of the inner ring 12 is located on the belt 21 side to convey the inner ring 12, the vertical line L passing through the center of gravity G of the inner ring 12 is the upper surface of the claw portion 22 as in the inner ring 12 shown in FIG. Since it is located in the range of the above or in the range on the belt 21 side of the upper surface of the claw portion 22, the inner ring 12 is conveyed to the next step without falling from the claw portion 22.

As described above, according to the single-row deep groove ball bearing 10 and the manufacturing method thereof of the present embodiment, the angle of intersection between the straight line E passing through the inner ring side surface portion 12i and the center of gravity G of the inner ring 12 and the central axis C of the inner ring 12. α is set in the range of 55 ° to 75 °, and the intersection β of the transport direction D of the elevator conveyor 20 and the horizontal plane F orthogonal to the gravity direction passes through the inner ring side bearing portion 12i and the center of gravity G of the inner ring 12. It is set to be equal to or greater than the intersection angle α between the straight line E and the central axis C of the inner ring 12. Therefore, the inner ring side surface portion 12i of the inner ring 12 slides down the claw side surface portion 22a of the claw portion 22 and slides down along the belt 21 without rotating the inner ring 12, so that the falling speed of the inner ring 12 is suppressed. It is possible to prevent damage to the inner ring 12.

Further, according to the single row deep groove ball bearing 10 of the present embodiment, since the second small diameter step portion 12 m is formed on the outer peripheral surface of the axial end portion of the inner ring 12, the first sealing device 15 is large in the radial direction. In addition, it is possible to further prevent water from entering from the fitting surface between the inner peripheral surface of the slinger 15a and the bottom surface 12n of the second small diameter step portion 12m, so that the water resistance of the bearing can be improved. ..

Further, according to the single row deep groove ball bearing 10 of the present embodiment, the second small diameter step portion 12m is formed by grinding at the same time as the inner ring raceway groove 12a, so that the second small diameter step portion 12m as shown in FIG. 1 is formed. The grinding resistance when grinding the shoulder portion 12b can be reduced as compared with the inner ring 12 which is not formed. More specifically, in the grinding process, the processing resistance, particularly the processing resistance in the radial direction, is larger than that in the cutting process, so that the object to be ground is easily deformed. Therefore, in the present embodiment, the second small diameter step portion 12m is provided to reduce the grinding portion when grinding the shoulder portion 12b. As a result, the grinding resistance can be lowered, so that the roundness of the inner ring 12 can be increased.
Other configurations and actions and effects are the same as those in the first embodiment.

The present invention is not limited to those exemplified in the above embodiments, and can be appropriately modified without departing from the gist of the present invention.
For example, in the above embodiment, the case where the present invention is applied to an inner ring having an asymmetric structure in the axial direction is exemplified, but the present invention is not limited to this, and the present invention may be applied to an inner ring having a symmetrical structure in the axial direction. In this case, it can be used, for example, when the directions of the markings on the inner ring are aligned.
Further, in the above embodiment, the inner ring side chamfer portion is a tapered chamfer and the claw side surface chamfer is a curved surface chamfer, but the present invention is not limited to this, and the inner ring side surface chamfer portion is a curved surface chamfer and the claw side surface. The chamfered portion may be a tapered chamfer. Further, both the inner ring side chamfer portion and the claw side surface chamfer portion may be tapered chamfered or curved chamfered.

10 ball bearings (single row deep groove ball bearings)
11 Outer ring 11a Outer ring raceway groove 11b Shoulder part 12 Inner ring raceway groove 12b Inner ring raceway groove 12b Shoulder part 12c Axial direction one end surface 12d Axial direction other end surface 12e Surfaced part 12f First small diameter step part 12g Bottom surface 12h Side surface 12i Inner ring side surface Small diameter step part 12n Bottom surface 12p Side surface 13 Multiple balls 14 Cage 15 First sealing device 16 Second sealing device 20 Elevator conveyor 21 Belt 22 Claw part 22a Claw side taking part B1 From inner ring raceway groove to one end surface in the axial direction of the inner ring Axial dimension B2 Axial dimension from the inner ring raceway groove to the other end surface of the inner ring in the axial direction C Central axis of the inner ring D Transport direction of the elevator conveyor G Center of gravity L Vertical line E Straight line passing through the side surface of the inner ring and the center of gravity of the inner ring F Gravity direction Horizontal plane orthogonal to α α Intersection angle between the straight line passing through the inner ring side surface and the center of gravity of the inner ring and the central axis of the inner ring β Intersection angle between the horizontal plane orthogonal to the transport direction of the elevator conveyor and the direction of gravity

Claims (5)

An outer ring having an outer ring raceway groove formed on the inner peripheral surface, an inner ring having an inner ring raceway groove formed on the outer peripheral surface, and a plurality of balls rotatably provided between the outer ring raceway groove and the inner ring raceway groove. A single row deep groove ball bearing with,
The inner ring has an axially asymmetric structure in which the shapes of one end in the axial direction and the other end in the axial direction are different across the inner ring raceway groove.
A first small diameter step is provided at the other end of the inner ring in the axial direction.
The outer peripheral edge of the shoulder portion on the other end side in the axial direction of the pair of shoulder portions adjacent to the inner ring raceway groove of the inner ring is larger than the chamfered portion provided on the outer peripheral edge of the shoulder portion on the one end side in the axial direction. A chamfer is provided,
The axial dimension from the inner ring raceway groove to the axial end surface of the inner ring is larger than the axial dimension from the inner ring raceway groove to the axial end surface of the inner ring.
A single-row deep groove ball bearing characterized in that one end portion in the axial direction of the inner ring projects outward in the axial direction from the one end surface in the axial direction of the outer ring. The first small diameter step portion is arranged inside the vehicle in the vehicle assembled state.
The single-row deep-groove ball bearing according to claim 1, wherein the single-row deep-groove ball bearing is a semi-floating rear wheel axle ball bearing. The single row according to claim 1 or 2, wherein the intersection angle between the straight line passing through the inner ring side bearing portion and the center of gravity of the inner ring and the central axis of the inner ring is set in the range of 55 ° to 75 °. Deep groove ball bearing. The method for manufacturing a single-row deep groove ball bearing according to any one of claims 1 to 3.
The inner ring is conveyed from the bottom to the top by an elevator conveyor arranged diagonally with respect to the direction of gravity.
The elevator conveyor includes a belt and a claw portion provided on the surface of the belt and on which the inner ring is placed.
The claw portion is formed in a rectangular shape in a cross-sectional view in the direction of gravity.
A claw side surface is provided on the edge between the upper surface and the front surface of the claw portion.
When the inner ring is conveyed by the claw portion of the elevator conveyor, the inner ring side surface picking portion is positioned so as to face the claw side surface picking portion and is located on a vertical line passing through the center of gravity of the inner ring. A characteristic method for manufacturing single-row deep groove ball bearings. A second small diameter step is provided at one end of the inner ring in the axial direction.
The second small diameter step portion is provided by grinding at the same time as the inner ring raceway groove.
The intersection angle between the transport direction of the elevator conveyor and the horizontal plane orthogonal to the gravity direction is set to be equal to or larger than the intersection angle between the straight line passing through the inner ring side bearing portion and the center of gravity of the inner ring and the central axis of the inner ring. The method for manufacturing a single-row deep groove ball bearing according to claim 4.

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