JP2015055274A - Thrust roller bearing, and method of manufacturing thrust roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust roller bearing and a method of manufacturing the thrust roller bearing capable of lowering torque by reducing rotational resistance due to friction between a pocket inner wall surface and a roller end face, and having a shape capable of being processed with high accuracy.SOLUTION: A thrust roller bearing includes a cage 5 having an annular portion 7 composed of an annular plate and provided with a plurality of pockets 6 arranged in the circumferential direction, and rollers 4. An inner wall surface at an outer diameter side, of the pocket 6 is formed by an outer peripheral portion 51 disposed at an outer diameter side of the annular portion 7, and its inner wall surface at an inner diameter side is composed of an inner peripheral portion 52 disposed at an inner diameter side of the annular portion 7, the outer peripheral portion 51 and the inner peripheral portion 52 of the annular portion 7 are axially inclined from the inner wall surfaces facing each other in the radial direction of the pocket 6, and further a pair of projecting portions projecting toward centers 4a, 4b of end faces 4c, 4d of the roller 4, are disposed. Projecting tips 53a, 54a of the projecting portions are formed into the circular arc shape, and centers 4a, 4b of apex end faces 4c, 4d of the tips are kept into point-contact with the centers 4a, 4b of the end faces 4c, 4d of the roller 4.

Description

  The present invention relates to a thrust roller bearing and a method of manufacturing a thrust roller bearing.

  For example, a thrust roller bearing used in an automobile torque converter is disposed between a stator fixed to a housing and a rotating body that rotates eccentrically with respect to the stator. This thrust roller bearing includes a roller, a cage for holding the roller, and a pair of race rings having a raceway surface for rolling the roller, and comes into contact with and faces the stator and the rotary body as the rotary body rotates eccentrically. The bearing ring rotates eccentrically. When the amount of eccentricity is larger than the internal clearance in the radial direction of the bearing, the eccentric rotating ring comes into contact with the cage in the radial direction, and the cage receives a load in the radial direction.

  And this thrust roller bearing has accommodated the roller in the pocket of the planar view rectangle provided in the holder | retainer. Since the roller is urged radially outward by the action of the rotational centrifugal force, the axial end surface of the roller contacts and slides on the inner wall surface on the outer diameter side of the pocket. Further, when the cage receives a load in the radial direction due to the eccentric rotation of the bearing ring, the axial end surface of the roller slides on the inner wall surface of the pocket. The friction at these sliding portions becomes the rotational resistance of the thrust roller bearing, and the rotational resistance increases and the loss of rotational torque tends to increase as the rotational speed increases. In order to reduce the fuel consumption of automobiles, it is desired to reduce the rotational resistance of thrust roller bearings as much as possible to reduce the torque.

  Therefore, in the conventional thrust roller bearing, the cage is made of an annular plate, and protrudes toward the end surface of the roller on the inner wall surface on the outer diameter side and inner diameter side of the pocket formed by punching in the thickness direction. , And has a convex portion bent in the axial direction. In this thrust roller bearing, the tip apex of the convex portion makes point contact with the center of the end face of the roller, thereby reducing rotational resistance and reducing torque (see Patent Document 1).

JP 2008-175310 A

  However, in the thrust roller bearing of the invention disclosed in Patent Document 1, for example, when used in a torque converter of an automobile that is required to be small and light, for example, the cage thickness is 0.5 mm and the protrusion of the convex portion When the amount is 0.5 mm, the protrusion amount of the convex portion is as small as the plate thickness, so that bending is difficult and processing accuracy is deteriorated. As a result, the contact with the end surface of the convex portion of the cage may not be stable, which may cause a reduction in life. Therefore, the thrust roller bearing has a problem of reducing the rotational resistance due to the friction between the inner wall surface of the pocket and the end surface, reducing the torque, and making the shape easy to process accurately.

  The present invention has been made in order to solve the above-described problems, and reduces the rotational resistance due to the friction between the inner wall surface of the pocket and the end surface, thereby reducing the torque and achieving a thrust with a shape that is easy to process accurately. It aims at providing the manufacturing method of a roller bearing and a thrust roller bearing.

  In order to solve the above-mentioned problem, the structural feature of the thrust roller bearing according to claim 1 is an annular portion comprising a circular plate, and a plurality of pockets formed by punching in the thickness direction are arranged in the circumferential direction. And a plurality of rollers held in each pocket, and the pocket is formed by an outer peripheral portion having an inner wall surface on the outer diameter side provided on the outer diameter side of the annular portion, The inner wall surface on the side is formed by an inner peripheral portion provided on the inner diameter side of the annular portion, and the outer peripheral portion and the inner peripheral portion of the annular portion are axially directed from the inner wall surface facing the radial direction of the pocket. Each of which has a pair of convex portions that project toward the center of the end face of the roller, the convex portions taper toward the projecting tips, and the tips are formed in an arc shape. Point contact with the center of the roller end face Is Rukoto.

  According to the thrust roller bearing of claim 1, the outer peripheral portion and the inner peripheral portion of the inclined annular portion of the cage have one of them as the center of the roller in the radial direction and the other in the state after the inclined formation. It can be formed up to the end of the direction. Thereby, in this thrust roller bearing, since a sufficient length can be secured for the cage to form the inclination, the inclination can be processed with high accuracy. Further, in this thrust roller bearing, the convex portions protruding from the outer peripheral portion of the annular portion and the inner wall surface of the inner peripheral portion taper toward the protruding tip, the tip is formed in an arc shape, and the apex of the tip is Point contact with the center of the roller end face. As a result, this thrust roller bearing can reduce rotational resistance due to friction between the inner wall surface of the pocket and the end surface, thereby reducing the torque.

  A structural feature of the thrust roller bearing according to claim 2 is that the thrust roller bearing further includes a pair of eccentric rings opposed to each other via the cage, and the cage includes a ring portion. The roller further includes a folded portion that extends from at least one of the outer circumferential portion and the inner circumferential portion of the annular portion and is folded back in the axial direction. This is because the portion is configured to slide in contact with the radial direction.

  According to the thrust roller bearing of claim 2, when the folded portion of the cage is configured to slide in contact with the raceway in the radial direction, the axial length of the folded portion is determined by the cage. Therefore, the area of the folded portion is increased. As a result, when a radial load is applied to the folded portion of the cage due to eccentric rotation, this thrust roller bearing can reduce the contact surface pressure due to this load and improve the seizure resistance.

  A structural feature of the method of manufacturing the thrust roller bearing according to claim 3 is that the annular portion of the cage is formed into a substantially M-shaped cross section by press drawing a single annular plate, and thereafter The pockets are formed by punching, and then the outer peripheral part and the inner peripheral part of the annular part are brought into contact with the inclined side surface in the axial direction of the cage in a state in which the mold is matched to the outer shape. The inclination is formed by pushing in the axial direction.

  According to the method of manufacturing the thrust roller bearing of claim 3, the cage is formed by forming the annular plate into a substantially M-shaped cross section, punching out the pockets, and then contacting the die with the inclined surface. Then, the inclination is formed by pushing the outer peripheral portion and inner peripheral portion of the annular portion in the axial direction. Thereby, since the manufacturing method of this thrust roller bearing forms an inclination according to the shape of the outer shape, the inclination can be processed with high accuracy. In addition, since the convex portions are formed at the same time when the outer peripheral portion and the inner peripheral portion of the annular portion are formed to be inclined, processing can be performed with high accuracy.

  A structural feature of the method of manufacturing the thrust roller bearing according to claim 4 is that the annular portion of the cage is formed in a substantially M-shaped cross section by press drawing a single annular plate, and In the state in which the folded portion is formed in a cylindrical shape, and then the pocket is punched and formed, and then the mold according to the outer shape is in contact with the inclined surface in the axial direction of the cage, The inclination is formed by pushing the end of the folded portion in the axial direction.

  According to the thrust roller bearing manufacturing method of claim 4, the cage is formed with an annular portion having a substantially M-shaped cross section, a folded portion is formed in a cylindrical shape, a pocket is formed by punching, and then an inclined portion is formed. Inclining is formed by pushing the end of the folded portion in the axial direction while the mold is in contact with the side surface. Thereby, since the manufacturing method of this thrust roller bearing forms an inclination according to the shape of the outer shape, the inclination can be processed with high accuracy. Further, since the slopes of the convex portions are formed simultaneously with the slopes of the flanges, they can be processed with high accuracy.

  ADVANTAGE OF THE INVENTION According to this invention, while reducing the rotational resistance by friction with an inner wall surface of a pocket, and an end surface, it can aim at low torque, and can provide the manufacturing method of a thrust roller bearing of the shape which is easy to process accurately.

It is sectional drawing of the thrust roller bearing which is one Embodiment of this invention. It is a side view which shows the state which hold | maintained the roller to the holder | retainer of FIG. It is AA sectional drawing of FIG. FIG. 4 is a view taken in the direction of arrow B in FIG. 3. It is a figure explaining the manufacturing procedure of a holder | retainer.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a thrust roller bearing of the present invention is embodied will be described with reference to the drawings.
FIG. 1 is a sectional view of a thrust roller bearing 1 according to an embodiment of the present invention. FIG. 2 is a side view showing a state in which the rollers 4 are held in the cage 5 of FIG.
As shown in FIGS. 1 and 2, the thrust roller bearing 1 is used, for example, in a torque converter (not shown) of an automobile. The torque converter includes an impeller 8 connected to an output shaft of an engine (not shown), a turbine (not shown) arranged opposite to the impeller 8 and connected to an input shaft of a transmission (not shown), a housing (Not shown) and a stator 9 attached via a one-way clutch (not shown). The torque converter acts as a fluid shaft joint, and the stator 9 and the impeller 8 are eccentric.

  The thrust roller bearing 1 includes a pair of race rings 2 and 3, a plurality of rollers 4 that roll between the pair of race rings 2 and 3, and a cage 5 that holds these rollers 4 in a rollable manner. Prepare.

  One raceway ring 2 is formed of an annular member made of, for example, a thin steel plate, and a raceway surface 2a is formed on the end surface of the roller 4 side. One raceway ring 2 is provided with an annular rising portion 2b that rises from the inner peripheral edge of the raceway surface 2a. The opposite surface of the raceway surface 2 a is in axial contact with the side surface of the large diameter portion 8 a of the impeller 8, and the inner periphery of the rising portion 2 b is disposed close to the outer peripheral surface 8 c of the small diameter portion 8 b of the impeller 8.

  The other race ring 3 is formed of an annular member made of, for example, a thin steel plate, and a raceway surface 3a is formed on the end surface on the roller 4 side. The other race ring 3 is provided with an annular rising portion 3b that rises from the outer peripheral edge portion of the raceway surface 3a. In the raceway ring 3, the opposite surface of the raceway surface 3 a is in contact with the stator 9 in the axial direction, and the outer periphery of the rising portion 3 b is fitted to the inner peripheral surface 9 a of the stator 9. As described above, the thrust roller bearing 1 is attached to the stator 9, sandwiched between the stator 9 and the impeller 8 in the axial direction, and receives an axial load.

  The plurality of rollers 4 are disposed between the raceway surface 3a of one raceway ring 3 and the raceway surface 2a of the other raceway ring 2, and are formed by needle rollers made of bearing steel. The plurality of rollers 4 roll on the raceway surface 3 a and the raceway surface 2 a in a pocket 6 (described later) of the cage 5.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 4 is a view taken in the direction of arrow B in FIG.
As shown in FIGS. 3 and 4, the cage 5 is entirely formed of an annular member made of a press-formed body of, for example, a galvanized steel plate, and includes an annular part 7, an outer peripheral part and an inner peripheral part of the annular part 7. And folded portions 55 and 56 extending from the portion.

  An annular portion main body 71 having a substantially M-shaped cross section is provided in a region in the radial direction of the annular portion 7. The annular part main body 71 includes an intermediate projecting part 7c, an outer diameter side projecting part 7a, and an inner diameter side projecting part 7b that are projected in the radial direction alternately on one side and the other side of the cage 5. The intermediate projecting portion 7c is projected to one side in the axial direction of the cage 5, and the outer diameter side projecting portion 7a and the inner diameter side projecting portion 7b are projected to the other axial direction.

  In the annular portion main body 71, pockets 6 having a rectangular shape in plan view are punched in the axial direction at several locations in the circumferential direction. The rollers 4 are housed in a non-separable manner so as to be rotatable with respect to the pockets 6. That is, into the pocket 6 at three points of the apex portions of the outer diameter side overhanging portion 7a, the inner diameter side overhanging portion 7b, and the intermediate overhanging portion 7c located on the inner wall surface of the pocket 6 on the left and right in the circumferential direction. Claws 7d, 7e, and 7f that protrude toward the surface are provided.

  By the claws 7d, 7e, and 7f, the three radial positions in each pocket 6 are narrower than the diameter dimension of the roller 4, so that the roller 4 does not come out of each pocket 6. . The rollers 4 are stored in each pocket 6 by being forcibly fitted.

  In the annular portion 7, an annular outer peripheral portion 51 that extends outward in the radial direction and is inclined to the other in the axial direction is provided on the outer diameter side of the annular portion main body 71. On the other hand, an annular inner peripheral portion 52 that extends inward in the radial direction and is inclined to the other in the axial direction is provided on the inner diameter side of the annular portion main body 71. The inclination angle θ1 at which the outer peripheral portion 51 and the inner peripheral portion 52 are inclined with respect to the axis C2 of the roller 4 is, for example, 30 degrees. In addition, the length L3 of the inclined outer peripheral portion 51 and inner peripheral portion 52 is approximately half the height L2 of the annular portion 7, that is, the height of the cage 5.

  The folded portions 55 and 56 are formed to extend from the outer peripheral edge portion of the outer peripheral portion 51 of the annular portion 7 and the inner peripheral portion of the inner peripheral portion 52 of the annular portion 7, and are folded back to one of the axial directions. The height L1 of the folded portions 55 and 56 is formed slightly lower than the height L2 of the annular portion 7. The axial positions of the tips of the folded portions 55 and 56 are substantially the same as the position of the intermediate projecting portion 7 c of the annular portion 7. The axial positions of the ends opposite to the tips of the folded portions 55 and 56 are slightly inside the positions of the outer diameter side protruding portion 7a and the inner diameter side protruding portion 7b of the annular portion 7.

  On the outer diameter side and the inner diameter side of the inner wall surface of the pocket 6, end faces 4 c and 4 d of the roller 4 from the inner peripheral edge portion of the outer peripheral portion 51 of the annular portion 7 and the outer peripheral portion of the inner peripheral portion 52 of the annular portion 7. Convex portions 53 and 54 projecting toward the centers 4a and 4b, respectively, are provided.

Next, the manufacturing procedure of the cage 5 will be briefly described with reference to FIG.
First, as shown in FIG. 5 (a), the cage 5 is formed by punching and forming a center hole in one galvanized steel sheet, and then applying a press drawing process to form an annular portion 7 having a substantially M-shaped section. Cylindrical folded portions 55 and 56 are formed. Thereafter, the pocket 6 is punched and formed, and then the outer portion is cut out. Simultaneously with the formation of the pocket 6, the convex portions 53, 54 and the claws 7d, 7e, 7f are formed.

  Thereafter, as shown in FIG. 5 (b), the ends of the folded portions 55, 56 are brought into contact with a die (die) 10 matched to the outer shape of the cage 5 on the other surface in the axial direction. The outer peripheral portion 51 and the inner peripheral portion 52 of the annular portion 7 are inclined by pushing the portions 55a and 56a from one side in the axial direction to the other side. By forming the outer peripheral portion 51 and the inner peripheral portion 52 of the annular portion 7 to be inclined, the convex portions 53 and 54 are also inclined.

Next, the detail of the convex parts 53 and 54 is demonstrated in the state before the outer peripheral part 51 and the inner peripheral part 52 of the annular part 7 incline, and the state after inclining.
The convex portions 53 and 54 in a state before the outer peripheral portion 51 and the inner peripheral portion 52 of the annular portion 7 are inclined taper in a substantially semicircular shape toward the protruding tip, and the tips 53a and 54a are arcuate. And the radial direction cross section of the convex parts 53 and 54 is formed in a substantially square shape.

  And in the state after the outer peripheral part 51 and the inner peripheral part 52 of the annular part 7 incline, the vertex 53b, 54b of the other side of the axial direction of the convex parts 53, 54 shown in FIG. , 4d closest to the center 4a, 4b.

Next, the operation of the thrust roller bearing 1 will be described.
When the bearing ring 2 abutting against the impeller 8 is relatively rotated with respect to the bearing ring 3 fitted to the stator 9, the raceway surfaces of the pair of bearing rings 2 and 3 with the rollers 4 held by the cage 5. Roll on 2a, 3a. As the roller 4 rolls, the cage 5 rotates while being guided by the roller 4, and the centers 4 a and 4 b of the end surfaces 4 c and 4 d of the roller 4 correspond to the vertices 53 b of the convex portions 53 and 54 of the cage 5. It slides in point contact with 54b.

  When the bearing ring 2 rotates eccentrically with respect to the bearing ring 3, the outer peripheral surface of the rising portion 2 b of the bearing ring 2 is the folded portion of the cage 5 when the eccentric amount is larger than the radial internal clearance of the bearing. 56, the cage 5 receives a radial load.

  In the thrust roller bearing 1 configured as described above, the length L3 of the outer peripheral portion 51 and the inner peripheral portion 52 of the inclined annular portion 7 is approximately half of the height of the cage 5, so that the cage 5 is A sufficient length for forming the inclination can be secured, and the inclination can be processed with high accuracy.

  Further, in this thrust roller bearing 1, the centers 4a and 4b of the end faces 4c and 4d of the roller 4 slide in point contact with the vertices 53b and 54b of the convex portions 53 and 54 of the cage 5, so that the sliding The rotational resistance due to the friction of the part can be reduced, and the torque can be reduced.

  Moreover, in this thrust roller bearing 1, since the axial lengths of the folded portions 55 and 56 of the cage 5 can be set up to near the height L2 of the cage 5, the areas of the folded portions 55 and 56 are large. Become. When a radial load is applied to the folded portions 55 and 56 due to eccentric rotation, the contact surface pressure due to this load can be reduced, and seizure resistance can be improved.

In addition, this invention is not limited to this embodiment, In the range which does not deviate from the summary of this invention, it can implement with a various form.
In the present embodiment, the cage 5 of the thrust roller bearing 1 has the folded portions 55 and 56. However, the present invention is not limited thereto. For example, when the pair of race rings do not rotate eccentrically, the cage has the folded portions. You may apply to the structure which is not.

1: thrust roller bearing, 2: bearing ring, 2a: raceway surface, 2b: rising portion, 3: bearing ring, 3a: raceway surface, 3b: rising portion, 4: roller, 4a, 4b: center, 4c, 4d: End face of roller, 5: Cage, 6: Pocket, 7: Ring part, 7a: Outer diameter side overhanging part, 7b: Inner diameter side overhanging part, 7c: Intermediate overhanging part, 7d, 7e, 7f: Claw 8: Impeller, 8a: Large diameter portion, 8b: Small diameter portion, 8c: Outer peripheral surface, 9: Stator, 9a: Inner peripheral surface, 10: Mold (mold), 51: Outer peripheral portion, 52: Inner peripheral portion, 53, 54: convex part, 53a, 54a: tip, 53b, 54b: apex, 55, 56: folded part, 55a, 56a: end part, 71: ring part main body

Claims (4)

A cage having an annular portion made of an annular plate and having a plurality of pockets formed by punching in the thickness direction and arranged in the circumferential direction;
A plurality of rollers held in each of the pockets,
The pocket is formed by an outer peripheral portion whose inner wall surface on the outer diameter side is provided on the outer diameter side of the annular portion, and an inner wall surface on the inner diameter side is formed by an inner peripheral portion provided on the inner diameter side of the annular portion. Configured
The outer peripheral portion and the inner peripheral portion of the annular portion are inclined in the axial direction from the inner wall surface facing the radial direction of the pocket, and each has a pair of convex portions protruding toward the center of the end face of the roller,
Each of the convex portions tapers toward the protruding tip, and the tip is formed in an arc shape,
A thrust roller bearing, wherein the apex of the tip makes point contact with the center of the end face of the roller. The thrust roller bearing further includes a pair of raceways opposed to each other via the cage and eccentric,
The retainer further includes a folded portion that extends from at least one of the outer peripheral portion of the annular portion and the inner peripheral portion of the annular portion and is folded back in the axial direction.
2. The thrust roller bearing according to claim 1, wherein the bearing ring is configured such that the roller slides and the folded portion contacts and slides in a radial direction. It is a manufacturing method of the thrust roller bearing according to claim 1,
The annular portion of the cage is formed in a substantially M-shaped cross section by press drawing on a single annular plate,
After that, the pocket is punched and formed,
After that, in the axial direction of the cage, with the mold in conformity with the outer shape on the inclined side surface, the outer peripheral portion and the inner peripheral portion of the annular portion are pushed in the axial direction to thereby reduce the inclination. A method of manufacturing a thrust roller bearing, comprising: forming a thrust roller bearing. It is a manufacturing method of the thrust roller bearing according to claim 2,
Forming the annular portion of the cage in a substantially M-shaped cross section by press-drawing a single annular plate, and forming the folded portion in a cylindrical shape,
After that, the pocket is punched and formed,
Thereafter, the tilt is formed by pushing the end portion of the folded portion in the axial direction in a state in which a die matching the outer shape is in contact with the inclined surface in the axial direction of the cage. A method for manufacturing a thrust roller bearing.

Images