JP4957571B2 - Thrust rolling bearing - Google Patents

Description

  The present invention relates to an improvement in a thrust rolling bearing that is incorporated between a pair of members that relatively rotate while receiving a large thrust load, such as a component of a tightening device of a steering wheel position adjusting device.

  Some tightening devices for steering wheel position adjusting devices such as tilt-type steering devices, telescopic steering devices, and tilt and telescopic steering devices incorporate thrust rolling bearings. As this thrust rolling bearing, it is possible to use a combination of a cage that holds a plurality of rolling elements and a pair of thrust races in a non-separable manner and a relative rotation that can be freely performed. It is preferable for facilitating the work. In view of such circumstances, it is considered to use a thrust rolling bearing 1 as shown in FIGS.

  The thrust rolling bearing 1 includes two thrust races 2 and 2, a cage 3, and a plurality of rollers 4 and 4 each of which is a rolling element. Thrust traces 2 and 2 are each formed in a ring shape from a hard metal plate such as bearing steel and case-hardened steel, and are formed at the inner end in the axial direction of the inner periphery (ends closer to each other). The thrust protrusions 5 and 5 that are thinner than the main body portions of the two thrust races 2 and 2 are formed over the entire circumference. The cage 3 is made of a synthetic resin such as polyamide resin or polyphenylene sulfide resin by injection molding, and is formed into a ring shape as a whole. A cylindrical portion 7 is formed on the inner peripheral edge of the ring-shaped main body portion 6. In addition, it is formed so as to protrude from the main body portion 6 to both sides in the axial direction over the entire circumference. In addition, a plurality of pockets 8 and 8 are provided at equal intervals in the circumferential direction in the radially intermediate portion of the main body portion 6, and between the pockets 8 and 8 adjacent in the circumferential direction as column portions 9 and 9. Yes. The interval between the column portions 9 adjacent to each other in the circumferential direction (the inner dimensions of the pockets 8 and 8) is larger than the outer diameters of the rollers 4 and 4 at the openings in the axial ends of the pockets 8 and 8. Is slightly smaller and slightly larger than the outer diameter of each of the rollers 4 and 4 in the middle. Accordingly, the rollers 4 and 4 can be inserted into the pockets 8 and 8 while elastically deforming the column portions 9 and 9 in the circumferential direction. Then, after the insertion, the rollers 4, 4 can be rotatably held in the pockets 8, 8. Further, locking concave grooves 10 and 10 are formed over the entire circumference at positions where the main body portion 6 is sandwiched from both axial sides at two axial positions on the outer peripheral surface of the cylindrical portion 7.

  The respective members 2, 3, and 4 each having the shape as described above constitute the thrust rolling bearing 1 in combination as follows. That is, the rollers 4 and 4 are held in the pockets 8 and 8 of the retainer 3, and the locking protrusions 5 and 5 formed on the inner peripheral edges of the thrust races 2 and 2 are The locking grooves 10 and 10 are locked. This locking operation is performed while elastically deforming both ends in the axial direction of the cylindrical portion 7 in the direction of reducing the outer diameter. Then, in the state after the locking, the thrust rolling bearing 1 is obtained by combining the thrust races 2 and 2 with the retainer 3 so as to be relatively rotatable and non-separable. In such a thrust rolling bearing 1, the constituent members 2, 3, 4 are combined in a non-separable manner, so that parts management, assembly work such as the tightening device can be facilitated.

  In the case of the thrust rolling bearing 1 considered above, parts management and assembling work can be facilitated, but there is room for improvement in terms of obtaining stable quality. That is, in order to combine the retainer 3 and the two thrust traces 2 and 2 in a relatively rotatable and non-separable manner, the locking protrusions 5 and 5 at the inner peripheral edge of the two thrust traces 2 and 2 are connected to the cylinder. When locking in the locking grooves 10, 10 on the outer peripheral surface of the portion 7, both axial end portions of the outer peripheral surface of the cylindrical portion 7 are easily damaged. Specifically, since the deformation resistance of both ends of the cylindrical portion 7 in the axial direction is large, the cylindrical portion 7 is pushed when the locking ridges 5 and 5 are pushed into the locking grooves 10 and 10. There is a possibility that the portions strongly pressed by both the locking protrusions 5 and 5 at the both ends in the axial direction are cut off to generate burrs, or in the case of remarkable damage, these portions may be lost. In the case of the thrust rolling bearing 1 incorporated in the tightening device of the steering wheel position adjusting device, the rotational speed of use is slow, so that there is no particular inconvenience, but in order to make the operation of the tightening device smooth. It is not preferable that the above damage occurs.

  On the other hand, if the cage is divided into two as in the structure of the rolling bearing described in Patent Document 1, damage during assembly can be prevented. However, although it is good when the radial rolling bearing as described in the above-mentioned Patent Document 1 is a target, when the thrust rolling bearing retainer as a target of the present invention is divided into two, It is difficult to stably combine the thrust trace with the non-separated state. Further, as shown by chain lines in FIGS. 8 to 13, the cylindrical portion 7 is formed by forming notches 11 and 11 at a plurality of circumferential portions of the cylindrical portion 7 protruding from the main body portion 6. If the rigidity is reduced, the damage can be prevented to some extent, but the effect is limited.

JP 2007-24142 A

  In view of the circumstances as described above, the present invention makes it difficult to damage the retainer when combining a synthetic resin retainer and a hard metal thrust trace, and after combining these retainers. And the thrust trace are invented to realize a structure that can be surely brought into a non-separated state.

The thrust roller bearing according to the present invention includes at least one thrust trace, a cage, and a plurality of rolling elements, similarly to the thrust rolling bearing previously considered.
Of these, the thrust trace is formed in an annular shape from a metal plate.
The cage is made of a synthetic resin in a ring shape, and has pockets at a plurality of locations in the circumferential direction at the radial intermediate portion.
The rolling elements are in rolling contact with the axial side surfaces of the thrust traces in a state in which the rolling elements are slidably held in the pockets of the cage.
Then, the thrust trace and the cage are formed over the entire circumferential length of the cylindrical portion on the outer peripheral surface of the cylindrical portion provided in the axially protruding state on the inner peripheral edge of the cage. By engaging the engaging concave groove and the inner peripheral edge of the thrust trace, they are combined in a non-separable manner.

  In particular, in the case of the thrust rolling bearing according to the present invention, the cage is provided with a single cut continuous from the inner peripheral edge to the outer peripheral edge at one position in the circumferential direction (so-called one-break structure). . Then, in the free state of the cage in which the width of the cut is elastically expanded, the outer diameter of the tip of the cylindrical portion is larger than the inner diameter of the thrust trace, and the bottom of the locking groove is The diameter is less than the inner diameter of this thrust trace.

  In the case of carrying out the thrust rolling bearing of the present invention as described above, more specifically, as in the invention described in claim 2, the cylindrical portion of the inner peripheral portion of the cage is provided with the respective pockets. It is provided in a state protruding from the main body part on both sides in the axial direction. Further, locking concave grooves are respectively formed at positions where the main body portion is sandwiched from both sides in the axial direction at two axial end portions of the cylindrical portion. Then, the inner peripheral edges of a pair of thrust races arranged at positions sandwiching the main body portion from both sides in the axial direction are respectively engaged with the both locking grooves.

According to the present invention configured as described above, when the synthetic resin cage and the hard metal thrust race are combined, the cage can be made less likely to be damaged. A thrust rolling bearing that can ensure that the thrust trace is not separated can be realized.
That is, the diameter of the cage provided with a continuous cut from the inner peripheral edge to the outer peripheral edge at one position in the circumferential direction can be reduced relatively easily. Then, in a state where the diameter of the cage is reduced, if the inner peripheral edge of the thrust trace and the engaging groove formed on the outer peripheral surface of the cylindrical portion of the cage are engaged, this engagement work can be performed. At the same time, the outer peripheral surface of the end of the cylindrical portion is not damaged. For this reason, smooth operation of various mechanical devices incorporating the thrust rolling bearing, such as a tightening device of a steering wheel position adjusting device, can be ensured.
Even if a large-diameter portion exists in the middle portion of the shaft, the large-diameter portion can be passed in the axial direction by elastically expanding the inner diameter of the cage. For this reason, the freedom degree of the installation position of a thrust rolling bearing improves.

  1 to 7 show an example of an embodiment of the present invention. The thrust rolling bearing 1a of this example is characterized by a single continuous ring from the inner peripheral edge to the outer peripheral edge of the retainer 3a at one position in the circumferential direction of the annular body portion 6a constituting the retainer 3a. A cut 12 is provided to make it difficult for the retainer 3a to be damaged when the retainer 3a and the pair of thrust traces 2 and 2 are combined. Since the configuration and operation of the other parts are the same as those of the thrust rolling bearing 1 previously considered with reference to FIGS. 8 to 13, the same parts are denoted by the same reference numerals, and redundant description is omitted. The description will focus on the features of this example.

  The cage 3a is made of a synthetic resin such as polyamide resin or polyphenylene sulfide resin by injection molding as a whole in a ring shape, and the cylindrical portion 13 is formed on the inner peripheral edge of the ring-shaped main body portion 6a. Except for the cut 12 portion, it extends over the entire circumference and protrudes from the main body portion 6a to both sides in the axial direction. And the said cut | interruption 12 is formed in the circumferential direction part of the said holder | retainer 3a in the state which continues from the inner periphery of this holder | retainer 3a to an outer periphery. That is, one end of the cut 12 is opened on the inner peripheral surface of the cylindrical portion 13, and the other end is opened on the outer peripheral edge of the main body portion 6a. The shape of the cut 12 in the free state of the cage 3a is not particularly limited. For example, both side edges of the cut 12 may be parallel to each other, or may be gently inclined toward each other toward the radially outer side of the main body portion 6a. However, with regard to the width dimension in the circumferential direction, a dimension that can easily engage with the locking protrusions 5 and 5 and the locking grooves 10 and 10 described later is secured. Further, the pitch of the pockets 8 and 8 formed in the main body portion 6a is not particularly limited. In the illustrated example, the pitch α of the portion sandwiching the cut 12 is larger than the pitch β of the other portion (α> β). The reason for this is to secure the width dimension of the column portions 9a, 9a existing between the cut 12 and the adjacent pockets 8, 8, and to ensure the strength of both the column portions 9a, 9a.

According to the thrust rolling bearing 1a of the present example configured as described above, when the synthetic resin cage 3a is combined with the pair of thrust races 2, 2 each made of hard metal, this cage 3a can be made harder to damage. Further, after the combination, the cage 3a and the thrust traces 2 and 2 can be surely brought into a non-separated state.
That is, the diameter of the cage 3a provided with a continuous cut 12 from the inner peripheral edge to the outer peripheral edge at one position in the circumferential direction can be obtained by applying a force in a direction (compression direction) approaching each other from the left and right sides in FIG. It can be shrunk relatively easily. Then, in the state where the diameter of the cage 3a is reduced in this way, the locking protrusions 5 and 5 provided on the inner peripheral edge portions of the two thrust traces 2 and 2 are connected to the outer peripheral surface of the cylindrical portion 13. If the force that has shrunk the diameter of the cage 3a is released after being arranged around the locking grooves 10 and 10 formed in the above, the both locking grooves 10 and 10 and the both locking protrusions The parts 5 and 5 can be engaged. In this state, the cage 3a and the thrust traces 2 and 2 are combined in a non-separable and relatively rotatable manner.

  In the engaging operation performed as described above, the locking protrusions 5 and 5 and the outer peripheral surface of the cylindrical portion 13 do not rub against each other. Therefore, the outer peripheral surface of the end portion of the cylindrical portion 13 is not damaged with the engagement operation. Therefore, for example, the operation of various mechanical devices incorporating the thrust rolling bearing 1a, such as a tightening device of a steering wheel position adjusting device, can be reliably achieved.

  Although the illustrated example shows the case where the present invention is applied to a thrust roller bearing, the present invention can also be applied to a thrust ball bearing. Further, the thrust rolling bearing is not limited to the tightening device of the steering wheel position adjusting device, but is also the rotation support portion of other various mechanical devices. However, it is assumed that the cage provided with the cut is used at a low speed so as not to be deformed by centrifugal force.

Sectional drawing regarding the virtual plane containing the central axis which shows an example of embodiment of this invention. Sectional drawing which took out the rolling element and the holder | retainer, and was seen from the same direction as FIG. The figure seen from the upper part of FIG. The exploded perspective view containing all the components. The perspective view which takes out and shows only a holder | retainer. The figure seen from the same axial direction. AA sectional drawing of FIG. Sectional drawing which shows an example of the structure considered previously. The figure which took out the rolling element and the holder | retainer and was seen from the upper direction of FIG. The exploded perspective view containing all the components. The perspective view which takes out and shows only a holder | retainer. The figure seen from the same axial direction. BB sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1a Thrust rolling bearing 2 Thrust trace 3, 3a Cage 4 Roller 5 Locking protrusion 6, 6a Body part 7 Cylindrical part 8 Pocket 9, 9a Pillar part 10 Locking groove 11 Notch 12 Notch 13 Cylindrical shape Part

Claims (2)

  At least one thrust race formed in a ring shape by a metal plate, a cage made of a synthetic resin in a ring shape, and provided with pockets in a plurality of circumferential directions in a radial intermediate portion; A plurality of rolling elements in which the respective rolling surfaces are brought into rolling contact with one side surface in the axial direction of the thrust race while being held in a pocket so as to be freely rollable. And a retaining groove formed on the outer peripheral surface of the cylindrical portion provided in the axially protruding state on the inner peripheral edge of the cage over the entire circumferential length of the cylindrical portion, and the thrust trace A thrust rolling bearing that is non-separably combined by engaging with the peripheral edge, wherein the cage is provided at a single circumferential position from the inner peripheral edge to the outer peripheral edge. And the width of this cut In the free state of the cage that is elastically expanded, the outer diameter of the tip of the cylindrical portion is larger than the inner diameter of the thrust race, and the diameter of the bottom of the locking groove is the inner diameter of the thrust trace. Thrust rolling bearing that is less than.   The cylindrical portion of the inner peripheral edge of the cage is provided in a state of projecting to both sides in the axial direction from the main body portion provided with each pocket, and the main body portion is positioned at two axial end portions of the cylindrical portion. Are formed at the positions sandwiching from both sides in the axial direction, and the inner peripheral edges of a pair of thrust traces disposed at the positions sandwiching the main body portion from both sides in the axial direction are respectively formed in the both retaining grooves. The thrust rolling bearing according to claim 1, which is engaged.

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