JP2012172763A - Thrust roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure which achieves reduction in the size and the weight of a machine including a thrust roller bearing and the facilitation of the assembling work of the thrust roller bearing.SOLUTION: The thrust roller bearing has a constitution in which a thrust race is not provided, and surfaces of relatively rotated first and second members 24 and 25 themselves serve as first and second thrust raceways 26 and 27. A locking projection 39 formed at the second member 25 and a locking projection piece 34 formed at the peripheral edge of a cage 3a are engaged with each other to combine the second member 25, the cage 3a and a roller 2 so as to be inseparable.

Description

  The present invention relates to an improvement in a thrust roller bearing (including a thrust needle bearing) used in a state where it is assembled to a rotating portion of a transmission or the like of an automobile in order to support the thrust load.

  For example, a thrust roller bearing as described in Patent Documents 1 to 3 is mounted on a rotating portion of a transmission or the like so as to support a thrust load applied to a rotating shaft or the like. 7 to 8 show an example of a thrust roller bearing 1 that has been widely known in the past. The thrust roller bearing 1 includes a plurality of rollers 2 arranged in a radial direction, a cage 3 that holds the rollers 2, and a pair of thrust traces 4 and 5 that clamp the rollers 2 from both sides. Become. This cage 3 is formed by combining first and second cage elements 31 and 32, each of which is U-shaped in cross section and formed into an annular shape, in a hollow annular shape, and has the same number of pockets 33 as the rollers 2. Are arranged radially. In a state where both the cage elements 31 and 32 are combined, the rollers 2 are prevented from falling out of the pockets 33 based on the engagement between the respective rolling surfaces and the opening edges of the pockets 33. is doing.

  Each of the thrust traces 4 and 5 is made of a hard metal plate having sufficient hardness, such as bearing steel or case-hardened steel, and has a short cylindrical flange on the inner or outer periphery. 6 and 7 are formed. Of these, the plurality of tip end portions of the flange 6 arranged on the radially outer side are bent radially inward, and the plurality of tip end portions of the flange 7 arranged on the radially inner side are bent radially outward, respectively. Locking protrusions 8 and 9 are provided. Then, the engaging protrusions 8 and 9 and the outer peripheral edge or inner peripheral edge of the cage 3 are engaged with each other so that the components of the thrust roller bearing 1 are coupled to each other without separation. Further, the reverse assembly preventing projections 10 and 10 are formed by bending a plurality of distal end portions of the flange 6 arranged on the radially outer side outwardly in the radial direction.

  The thrust roller bearing 1 as described above is mounted, for example, on the rotating portion where the thrust load is generated in a state in which the thrust trace 4 is fitted in a circular holding recess 12 formed in the casing 11. In this state, of the both side surfaces in the axial direction of the thrust trace 4, the side surface opposite to the thrust raceway surface with which the rolling surface of the roller 2 is in contact (the right side surface in FIG. 7) is the back of the holding recess 12. The side surface (the left side surface in FIG. 7) opposite to the thrust raceway surface with which the rolling surface of the roller 2 is in contact with the other side surface in the axial direction of the other thrust trace 5 is the mating member. 14 is in contact with the end face 15 of the base plate. As a result, the mating member 14 is rotatably supported with respect to the casing 11 and a thrust load acting between the two members 11 and 14 is supported.

  Patent Documents 1 and 3 describe structures for preventing separation between a thrust race and a member that abuts the thrust race. FIG. 9 shows a conventional structure described in Patent Document 3 among them. In the case of this conventional structure, a retaining piece 16 formed by bending a plurality of circumferential positions of the flange 7a formed on the inner peripheral edge of the thrust trace 5a radially inward, and a cylindrical surface 17 of the casing 11a. The stop recess 18 is engaged to prevent separation of the casing 11a and the thrust trace 5a.

  The conventional structures described in Patent Documents 1 and 3 are intended to prevent separation of a thrust raceway ring and a member that abuts the thrust raceway ring. Some do not have. For example, a part of a transmission, a part of a rotating shaft, and installed around the rotating shaft. The synchromesh mechanism rotates relative to the rotating shaft and synchronizes with the rotating shaft. In the case of a thrust roller bearing provided between a gear that can be switched between states, it is easy to omit the thrust race. That is, in the above-described part, the thrust roller bearing is installed between the stepped surface provided in a part of the rotating shaft and the axial end surface of the gear. In such a part, if these rotating shafts and gears are materials that can sufficiently harden the surface by heat treatment such as medium carbon steel, high speed steel, bearing steel, quenching, carbonitriding, etc. if necessary, A thrust raceway surface can be directly formed on each surface. In this case, for example, a first thrust raceway surface that is concentric with the central axis is formed on a step surface that exists in a direction orthogonal to the central axis of the rotation shaft, and the first thrust raceway is formed on the axial end surface of the gear. A second thrust raceway surface is formed parallel to the surface. If the thrust trace is omitted in this way, the axial dimension can be shortened by the thickness of the thrust trace, which is advantageous in terms of miniaturization and weight reduction, and also facilitates assembly work. I can plan.

  However, in the structure in which the thrust trace is omitted, a separation preventing structure based on the engagement between the retaining piece 16 formed on the thrust trace 5a and the locking recess 18 formed on the casing 11a side as shown in FIG. 9 is adopted. Can not. In Patent Document 4, as shown in FIG. 10, a bent portion 21 formed in a state of being bent radially inward at an end portion of a cage 20 constituting a radial roller bearing 19, and an end portion of a rotating shaft 22 are provided. A structure in which the formed locking groove 23 is engaged is described. With such a structure, the radial roller bearing 19 can be prevented from slipping out of the rotary shaft 22, but it cannot be applied to a thrust roller bearing without a race as it is.

JP 50-119145 A JP 2004-28342 A No. 7-16101 West German Patent Disclosure, DT2318341

  In view of the circumstances as described above, the present invention has a structure in which the surface itself of a pair of relatively rotating members does not have a thrust trace and is a thrust track surface, and at least one of these members, It was invented to realize a structure that can combine the cage and the roller in a non-separable manner, and can achieve a reduction in size and weight of the mechanical device incorporating the thrust roller bearing and facilitating the assembly work of the thrust roller bearing. Is.

  A thrust roller bearing according to the present invention includes a first member directly provided with a first thrust raceway surface, a second member directly provided with a second thrust raceway surface, a relative member rotating relative to the first member, a cage, And a plurality of rollers provided in a freely rollable manner in each pocket provided at a plurality of locations in the circumferential direction of the cage. Then, based on the engagement between the opening edge portions of these pockets and the rolling surfaces of these rollers, the rollers are prevented from falling off from the pockets.

In particular, the thrust roller bearing of the present invention includes a locking protrusion and a locking protrusion.
Of these, the locking protrusion is formed on a part of at least one of the first and second members in a state of projecting in a radial direction from a portion adjacent to the center side in the axial direction. ing.
Moreover, the said locking protrusion is provided in the state which protrudes in the radial direction at the peripheral part of the said holder | retainer.
Then, the locking protrusions and the locking protrusions are engaged with each other in a state where the locking protrusions are positioned closer to the central side than the locking protrusions in the axial direction. ing.
Further, by this engagement, the retainer and the rollers and the at least one member are combined in a non-separable manner and capable of relative rotation between the retainer and at least one member.

  According to the thrust roller bearing of the present invention configured as described above, it has a structure in which the surface itself of a pair of relatively rotating members does not have a thrust trace and is a thrust raceway surface, and at least one of these two members. The member, the cage and the roller can be combined in a non-separable manner, so that the mechanical device incorporating the thrust roller bearing can be reduced in size and weight, and the assembly operation of the thrust roller bearing can be facilitated.

The fragmentary sectional view which shows the 1st example of embodiment of this invention. The figure which looked at the plate part for separation prevention provided in the inner diameter side part of the cage for thrust roller bearings from the left of FIG. The principal part sectional drawing which shows the 2nd example of embodiment of this invention. The principal part sectional view showing the 3rd example. Sectional drawing which shows the principal part which shows the 4th example. The principal part sectional view showing the 5th example. Sectional drawing of the principal part which shows the 1st example of a conventional structure. The figure which took out the thrust trace of the right side of FIG. 7, and was seen from the left side of the figure. Sectional drawing of the principal part which shows the 2nd example of a conventional structure. The partial cutting side view which shows the 3rd example.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention. In the structure of this example, a first member 24 such as a gear is supported around a rotary shaft 22a via a radial roller bearing 19a so as to be capable of relative rotation, and a part of the rotary shaft 22a A second member 25 such as a gear is also fitted and fixed to the portion slightly displaced in the axial direction from the installation position of the one member 24 by an interference fit, a key engagement or the like, and the second member 25 and the rotary shaft 22a. And rotate in sync with each other. Each of the first member 24 and the second member 25 is made of an iron-based metal whose surface can be hardened by heat treatment, such as medium carbon steel, bearing steel, high speed steel, etc. First and second thrust raceway surfaces 26 and 27 are provided. These thrust raceway surfaces 26 and 27 exist in a direction orthogonal to the central axis of the rotating shaft 22a and are parallel to each other. Further, the thrust raceways 26 and 27 are subjected to finishing processing such as cutting, polishing, and super finishing so as to have the required surface properties.

  A thrust roller bearing 1a is configured by providing a plurality of rollers 2 that are rotatably held by a cage 3a between the thrust raceway surfaces 26 and 27. The cage 3a is formed by bending a single metal plate into a crank shape in cross section and having an annular shape as a whole. The cage main portion 28 composed of a radially intermediate portion or an outer end portion is generally In particular, it is the same as a widely known cage called an M-type cage. Pockets 33a for holding the rollers 2 in a rollable manner are formed radially at a plurality of locations in the circumferential direction of the cage main portion 28. Further, the central flat plate portion 29 provided in the radial central portion of the cage main portion 28 and the both side flat plate portions 30a and 30b provided at positions sandwiching the central flat plate portion 29 from both sides with respect to the radial direction are described above. It exists on the opposite side in the radial direction of each roller 2 across the maximum diameter portion of each roller 2. Further, the width dimension of each pocket 33a in the circumferential direction of the cage 3a is slightly smaller than the maximum diameter of each roller 2 at each flat plate portion 29, 30a, 30b. Therefore, each of these rollers 2 is based on the engagement between the respective rolling surfaces and the circumferential edge of each of the flat plate portions 29, 30a, 30b constituting the opening edge of each of the pockets 33a. Dropping from each pocket 33a is prevented.

  In particular, the retainer 3a constituting the thrust roller bearing 1a of the present example is provided on the inner diameter side portion of the retainer main portion 28 in order to prevent separation between the retainer 3a and the second member 25. Locking protrusions 34 and 34 are formed. In the case of this example in order to form these locking protrusions 34, 34, an annular extension 35 that extends radially inward from the inner peripheral edge of the retainer main portion 28, and this extension 35 A cylindrical portion 36 bent in a direction approaching the second member 25 from the inner peripheral edge thereof, and a separation preventing plate portion 37 bent outward in the radial direction from the leading edge of the cylindrical portion 36 are provided. The separation preventing plate portion 37 is inclined in a direction approaching the second member 25 as it goes radially outward. The locking protrusions 34, which are partial arc-shaped protrusions, at a plurality of circumferentially equidistant positions (four in the illustrated example) on the outer peripheral edge of the separation preventing plate portion 37, 34 is formed in a state of protruding outward in the radial direction.

  On the other hand, an annular recess 38 is formed in a continuous state over the entire circumference in a portion near the inner diameter of one end face in the axial direction of the second member 25 facing the first member 24. Further, a locking protrusion 39 is formed at the opening side end of the inner peripheral surface of the annular recess 38 so as to protrude radially inward. The inner diameter of the locking protrusion 39 is slightly smaller than the diameter of the circumscribed circle of the locking protrusions 34, 34, and each of the locking protrusions 34 is within the outer peripheral edge of the separation preventing plate 37. , 34 is larger than the outer diameter of the portion deviated from. In addition, the width dimension of the locking groove 40 existing between the inner side surface of the locking protrusion 39 and the outer surface portion of the annular recess 38 is determined by the width of the locking protrusions 34, 34. It is sufficiently larger than the thickness dimension.

  The second member 25 and the cage 3 a are configured to elastically deform the separation preventing plate portion 37 inward in the radial direction, and to fix the locking protrusions 34, 34 to the inner diameter of the locking protrusion 39. The engagement protrusions 34, 34 and the engagement concave groove 40 are combined with each other through the side. In this state, the cage 3a and the rollers 2 and the second member 25 are combined in a non-separable manner and capable of relative rotation. Therefore, the first and second thrust raceways 26 and 27 are provided on the surfaces of the first and second members 24 and 25 that do not have a thrust trace and rotate relative to each other. The member 25 and the cage 3a and the roller 2 can be combined in a non-separable manner. Then, by omitting the thrust trace, it is possible to reduce the size and weight of a mechanical device such as a transmission incorporating the thrust roller bearing 1a and to facilitate the assembly work of the thrust roller bearing 1a.

[Second Example of Embodiment]
FIG. 3 shows a second example of the embodiment of the present invention. In the case of this example, in addition to the portion closer to the inner diameter of the retainer 3b, the locking protrusions 34a are formed at a plurality of locations in the circumferential direction of the outer peripheral edge. A locking protrusion 39a formed in a state of protruding radially inward is engaged with a radially outer end portion of one side of the shaft. The inner diameter of the locking protrusion 39a is smaller than the diameter of the circumscribed circle of the locking protrusions 34a, and the portion of the retainer 3b that is separated from the locking protrusions 34a in the circumferential direction. It is larger than the outer diameter. Further, the inner diameter of the locking groove 40a existing on the back side of the locking protrusion 39a is larger than the diameter of the circumscribed circle of each locking protrusion 34a. Therefore, in the case of the structure of this example, the first and second members 24a and 25 are combined with each other in a state in which separation is prevented and relative rotation is freely possible via the cage 3b.
Since the configuration and operation of the other parts are the same as in the first example of the above-described embodiment, the same parts are denoted by the same reference numerals, and redundant description is omitted.

[Third example of embodiment]
FIG. 4 shows a third example of the embodiment of the present invention. In the case of this example, the extension part 35 and the separation preventing plate part 37 (see FIG. 1) as in the first example of the above-described embodiment are not provided on the inner diameter side of the cage 3c, but the cage 3c. A plurality of circumferential portions of the tip edge portion of the cylindrical portion 36a formed so as to be overlapped with the inner peripheral surface portion are slightly bent radially inward to form a locking protrusion 34b. Further, a locking protrusion 39b is formed in a radially outwardly protruding tip portion of the cylindrical surface 41 formed in a portion closer to the inner diameter of the axial end surface of the first member 24b in a state of protruding radially outward. . And this latching protrusion 39b and each said latching protrusion 34b are engaged. The outer diameter of the locking protrusion 39b is larger than the diameter of the inscribed circle of each of the locking protrusions 34b, and is out of the cylindrical protrusion 36b in the circumferential direction within the cylindrical portion 36a. It is smaller than the outer diameter of the part. Further, the outer diameter of the cylindrical surface 41 is smaller than the diameter of the inscribed circle of each of the locking protrusions 34b. Therefore, in the case of the structure of this example, the first member 24b, the retainer 3c and the roller 2 are combined in a state where separation is prevented and relative rotation is freely possible.
Since the configuration and operation of the other parts are substantially the same as those of the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted.

[Fourth Example of Embodiment]
FIG. 5 shows a fourth example of the embodiment of the present invention. In the case of this example, in the cage 3d, the inner peripheral edge portion of the radially inner flat plate portion 30b is extended as it is in the radial direction without being bent to be an extension portion 35a, and the inner peripheral edge of the extension portion 35a The locking protrusions 34c are formed at a plurality of locations in the circumferential direction. Each locking protrusion 34c is engaged with a locking protrusion 39b provided on the first member 24b side.
Since the configuration and operation of the other parts are the same as in the third example of the above-described embodiment, the description regarding the equivalent parts is omitted.

[Fifth Example of Embodiment]
FIG. 6 shows a fifth example of the embodiment of the present invention. In the case of this example, as the retainer 3e, a combination of the first and second retainer elements 31a and 32a in a hollow annular shape is used. Then, a plurality of portions in the circumferential direction of the tip edge portion of the cylindrical portion 42 existing on the outer peripheral surface portion of the cage 3e are bent slightly outward in the radial direction to form a locking projection piece 34d. In addition, a locking protrusion 39c is formed in a state of projecting inward in the radial direction at the distal end portion of the radially inward cylindrical surface 41a formed at a portion near the outer diameter of the axial end surface of the second member 25a. . And this latching protrusion 39c and each said latching protrusion piece 34d are engaged. The inner diameter of the locking protrusion 39c is smaller than the diameter of the circumscribed circle of each of the locking protrusions 34d, and the portion of the cylindrical portion 42 that is separated from the locking protrusions 34d in the circumferential direction. It is larger than the outer diameter. Further, the inner diameter of the cylindrical surface 41a is larger than the diameter of the circumscribed circle of each locking projection piece 34b. Therefore, in the case of the structure of this example, the second member 25a, the retainer 3e, and the roller 2 are combined in a state where separation is prevented and relative rotation can be freely performed.
Since the configuration and operation of the other parts are substantially the same as those of the first example of the above-described embodiment, illustration and description regarding the equivalent parts are omitted.

  Each example shown in the figure shows a case where the present invention is applied to a thrust cylindrical roller bearing in which a plurality of cylindrical rollers are arranged on a pair of thrust raceway surfaces parallel to each other. However, the present invention can also be applied to a thrust tapered roller bearing. When applied to a thrust tapered roller bearing, the distance between a pair of thrust raceway surfaces is narrowed toward the inner side in the radial direction, and a plurality of tapered rollers are disposed between these thrust raceway surfaces. By adopting such a structure, the differential slip of the rolling contact portion between the rolling surface of each tapered roller and the thrust raceway surfaces is reduced or eliminated, and the dynamic torque (rotational resistance) of the thrust roller bearing is reduced. ) Can be reduced.

DESCRIPTION OF SYMBOLS 1, 1a Thrust roller bearing 2 Roller bearing 3, 3a, 3b, 3c, 3d, 3e Cage 4 Thrust trace 5, 5a Thrust trace 6, 6a Flange 7 Flange 8 Locking protrusion 9 Locking protrusion 10 Prevention of reverse assembly Protrusion 11, 11a Casing 12 Holding recess 13 Back surface 14 Mating member 15 End face 16 Retaining piece 17 Cylindrical surface 18 Locking recess 19, 19a Radial roller bearing 20 Cage 21 Bending portion 22, 22a Rotating shaft 23 Locking groove 24, 24a, 24b First member 25, 25a Second member 26 First thrust raceway surface 27 Second thrust raceway surface 28 Cage main part 29 Central plate part 30a, 30b Both side plate parts 31, 31a First cage element 32, 32a Second cage element 33, 33a Pocket 34, 34a, 34b, 34c, 34d Locking protrusion 35, 5a extensions 36,36a cylindrical portion 37 separated prevention plate part 38 annular recess 39,39a, 39b, 39c engaging protrusions 40,40a shield groove 41,41a cylindrical surface 42 cylindrical portion

Claims (2)

  A first member directly provided with a first thrust raceway surface concentric with the central axis, and a second member directly provided with a second thrust raceway surface opposed to the first thrust raceway surface and rotating relative to the first member; , The whole is formed in an annular shape, and each includes a cage provided with a plurality of radially extending pockets at a plurality of locations in the circumferential direction, and a plurality of rollers provided rotatably in each of these pockets, In the thrust roller bearing in which the rollers are prevented from falling off from the pockets based on the engagement between the opening edge portions of the pockets and the rolling surfaces of the rollers, both the first and second members are provided. A locking ridge formed on a part of at least one of the members in a state of projecting in a radial direction from a portion adjacent to the central side in the axial direction, and a peripheral edge of the cage in a radial direction The locking protrusion provided in the protruding state The retainer and the rollers and the at least one member are engaged with each other in a state in which the engagement protrusion is positioned closer to the central side than the engagement protrusion in the axial direction. A thrust roller bearing characterized in that these are combined in a non-separable manner so that the cage and at least one member can be relatively rotated.   The cage is formed by bending a metal plate, and the locking protrusions are formed at a plurality of locations in the circumferential direction of the cage so as to protrude in a radial direction from portions adjacent to each other in the circumferential direction. 2. The thrust roller bearing according to claim 1, wherein a diameter of a portion adjacent to the circumferential direction is a size capable of loosely passing through the locking protrusion.

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