JP2016200211A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing capable of flexibly corresponding to diameter change, and having versatility at low cost.SOLUTION: A rolling bearing 10 includes a plurality of rolling bodies arranged in an annular raceway space 11 formed between a roller 66 as an outside member and a shaft part 65 as an inside member, and a holder 13 holding the rolling bodies in a rollable manner. The holder 13 has an extension part 14 extending in an alignment direction of the rolling bodies in a state of storing the rolling bodies, arranged into an ended annular shape along the circumferential direction of the raceway space 11, and capable of enlarging/contracting the diameter.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a rolling bearing.

  A rolling bearing disclosed in Patent Document 1 includes a plurality of needles (rolling elements) disposed between an inner peripheral surface of an outer shell (outer member) and an outer peripheral surface of a journal (inner member), and rolls the needle. And a retainer (cage) for holding it. The retainer is closed in a ring shape along the orbital circle of the needle, and holds the needle in a pocket formed at intervals in the circumferential direction.

JP 2009-91974 A

  In the above case, if the diameter of the orbital circle of the needle is changed according to the outer diameter of the journal, a retainer having a diameter corresponding to the changed diameter has to be prepared. For this reason, it is necessary to prepare a retainer for each diameter for a plurality of types of journals having different diameters, and there is a problem that the mold cost increases and the versatility is inferior.

  The present invention has been completed based on the above circumstances, and an object thereof is to provide a low-cost and versatile rolling bearing that can flexibly cope with a diameter change.

  The present invention is a rolling bearing comprising a plurality of rolling elements arranged in an annular raceway space formed between an outer member and an inner member, and a cage that holds the rolling elements in a rollable manner. The retainer extends in the direction in which the rolling elements are arranged in a state in which the rolling elements are accommodated, and is disposed in an end ring shape along the circumferential direction of the orbital space so that the diameter can be expanded and contracted. It is characterized by having a part.

  When the diameter of the orbital space is changed, the extension portion is reduced or expanded to have a diameter corresponding to the changed diameter, so that the diameter change can be flexibly dealt with, and the versatility is excellent. Moreover, it is not necessary to prepare a dedicated cage for each diameter for a plurality of types of structures having different diameters of the orbital space, and the cost can be kept low.

It is sectional drawing of the rocker arm incorporating the rolling bearing which concerns on the Example of this invention. It is a principal part enlarged view of FIG. It is an enlarged view of the extension part of a linear state. FIG. 5 is an enlarged view showing a state in which the locking portion of the rolling bearing is arranged to be locked to the locking receiving portion of the rocker arm, and the rolling bearing is restricted from being detached from the rocker arm.

Preferred embodiments of the present invention are shown below.
The extending portion is displaced from a linear state extending linearly to an arc state bent in an arc shape along the circumferential direction of the orbit space. According to this, since the extension part can be formed as a linear state extending linearly at the time of manufacture, the manufacture becomes easier than making an annular shape or an arc shape.

  A plurality of notches that are the triggers for bending from the linear state to the circular arc state are provided at intervals in the portion of the extending portion that becomes the inner peripheral surface in the circular arc state. According to this, since the extension portion is bent with the notch as a trigger, the extension portion is smoothly guided to the circular arc state, and the assembling property of the extension portion to the track space is improved.

  The extending portions are arranged to face each other in pairs in the axial direction of the rolling elements via a plurality of connecting portions, and a pocket for accommodating the rolling elements is defined by the extending portions and the connecting portions, The notch part communicates with the pocket, and the adjacent connecting part is provided with an inner restricting part that restricts the rolling element from coming out in the inner diameter direction at a position close to the inner diameter facing the pocket. When the extending portion is displaced in the arc shape, the opening near the inner diameter between the adjacent connecting portions is narrowed, and the inner regulating portion is brought to a position where the rolling element can be prevented from coming out in the inner diameter direction.

  Both ends of the extension part are set to the formation position of the notch part. According to this, the extended part of a linear state can be manufactured more easily by cut | disconnecting the elongate member extended linearly in the suitable location corresponding to a notch part.

  The adjacent connecting portion is provided with an outer restricting portion for restricting the rolling element from coming out in the outer diameter direction at a position near the outer diameter facing the pocket, and the center of the pocket where the notch portion is communicated Serves as a fulcrum for bending into the arc state, and in the arc state, the rolling element is held between the outer restricting portion and the inner restricting portion so as to be capable of rolling with a clearance. According to this, it is possible to adjust the clearance to a constant clearance only by displacing the extending portion into the circular arc state, and to ensure smooth rolling of the rolling elements.

<Example>
Examples will be described below with reference to FIGS. The rolling bearing 10 which concerns on an Example illustrates the case where it incorporates in the rocker arm 60 which comprises the valve operating apparatus of the internal combustion engine of a motor vehicle.

First, the structure of the rocker arm 60 and the valve mechanism will be described.
As shown in FIG. 1, the rocker arm 60 has an arm body 61 extending in the front-rear direction (left-right direction in FIG. 1). The arm main body 61 has a pair of side wall portions 62 (only one is shown in FIG. 1) facing each other in the width direction (the thickness direction in FIG. 1). The front end portion of the arm body 61 is a receiving portion 63 that is connected to both side wall portions 62 and supported by a support member 70 such as a lash adjuster. The rear end portion of the arm body 61 is a pressing portion 64 that connects the side wall portions 62 to each other and presses the top portion 81 of the valve stem 80. A cylindrical shaft portion 65 (corresponding to an inner member) is fixed to the middle portion of the side wall portions 62 so as to penetrate in the width direction.

  In the middle part of the arm main body 61, the space SP surrounded by the side wall parts 62, the receiving part 63 and the pressing part 64 can be rotated via the rolling bearing 10 to the shaft part 65 horizontally mounted on the space SP. A cylindrical roller 66 (corresponding to the outer member) supported by the housing is accommodated. The outer peripheral surface of the roller 66 is in contact with the cam 50. The cam 50 is provided on a camshaft 51 that is arranged in parallel with the shaft portion 65 in the axial direction (width direction).

  Here, the support member 70 and the valve stem 80 are incorporated in a cylinder head (not shown). The rocker arm 60 is tilted with the support member 70 as a fulcrum by being pressed downward through the roller 66 by the rotation of the cam 50 while being supported from below by the top 81 of the valve stem 80 and the support member 70. . As the rocker arm 60 tilts, the pressing portion 64 presses the top 81 of the valve stem 80, and the valve stem 80 descends against the biasing force of a coil spring (not shown). Thereby, a valve (not shown) provided at the lower end of the valve stem 80 opens an intake or exhaust port (not shown). When the pressing force is further reduced by the rotation of the cam 50, the valve stem 80 is raised by the biasing force of the coil spring, and the valve closes the intake or exhaust port. Therefore, when the rocker arm 60 swings according to the rotation of the cam 50, the valve is repeatedly opened and closed.

Next, the structure of the rolling bearing 10 will be described.
As shown in FIG. 2, an annular orbit space 11 is formed between the outer peripheral surface of the shaft portion 65 and the inner peripheral surface of the roller 66. A plurality of cylindrical needles 12 (which are needle rollers and correspond to rolling elements) elongated in the axial direction are arranged in the track space 11. The width dimension (diameter dimension) of the orbit space 11 corresponds to the diameter of the needle 12 and is set to be constant over the entire circumference in the circumferential direction. The needles 12 arranged in the orbital space 11 are arranged in parallel in the circumferential direction with a predetermined interval while being held by the cage 13. The outer peripheral surface of the shaft portion 65 constitutes the inner peripheral raceway surface of the needle 12, and the inner peripheral surface of the roller 66 constitutes the outer peripheral raceway surface of the needle 12.

  The cage 13 is made of synthetic resin, and extends in a pair of extending portions 14 extending in a direction orthogonal to the width direction while facing in parallel in the width direction, and at a plurality of positions spaced in the extending direction. It consists of the connection part 15 along the width direction constructed between the protrusion parts 14. FIG. Both extending portions 14 are maintained at regular intervals in the width direction by the connecting portions 15. As shown in FIG. 3, the retainer 13 is provided with a pocket 16 that is elongated in the width direction between the extending portion 14 and the connecting portion 15. A plurality of pockets 16 are provided at intervals in the extending direction of the extending portion 14 by being partitioned by the connecting portion 15, and the needle 12 is accommodated therein so that it can roll (roll freely). The needle 12 is accommodated in the pocket 16 with its axis oriented in the width direction.

  The extending portion 14 has a strip-like shape extending from one end to the other end, and is linearly arranged at the time of molding (see FIG. 3), and inserted into the orbital space 11 to surround the orbital space 11. It is displaced to an arc state (see FIGS. 1 and 2) arranged in an arc shape along the direction.

  In the extended portion 14, U-shaped notch portions 17 are opened and provided at a plurality of positions spaced in the extending direction at a portion that becomes an inner peripheral surface in an arc state. Each notch portion 17 is arranged at a certain interval in the extending direction of the extending portion 14 at a position communicating with the pocket 16 corresponding to between the adjacent connecting portions 15. Specifically, the notch 17 is disposed at a position facing the radial center of both ends of the needle 12 accommodated in the pocket 16. As shown in FIG. 3 to FIG. 2, when the extending portion 14 changes from the straight state to the circular arc state, the opening of each notch portion 17 is narrowed, and accordingly, the extending portion 14 is bent inwardly to form the circular arc. Guided to the state. That is, each notch part 17 becomes a trigger of bending to an arc state. In addition, the extension part 14 is elastically urged | biased in the diameter expansion direction in the circular arc state, and it is possible to maintain the circular arc shape by the elastic force.

  At both ends in the width direction of the connecting portion 15, rib-shaped inner restricting portions 18 are provided to project at positions facing the inner diameter of the surface facing the pocket 16, and rib-shaped outer restricting portions are disposed at facing positions near the outer diameter. 19 protrudes. The inner restricting portion 18 and the outer restricting portion 19 are disposed at substantially point-symmetrical positions around the center of the pocket 16. As shown in FIG. 2, the needle 12 accommodated in the pocket 16 is held so as to be able to roll with a clearance (play) between the inner diameter restricting portion 18 and the outer diameter restricting portion 19 in the circular arc state. Escape from is regulated. In this case, the cut depth of the notch 17 is set so that the center of the pocket 16 becomes a fulcrum of bending, and the clearance is adjusted to be constant.

  As shown in FIG. 2, a pair of locking portions 21 projecting radially outward are provided at both ends of the extending portion 14 in the extending direction. As shown in FIG. 4, the locking portion 21 has a claw shape that gradually increases the amount of protrusion toward the inner side in the width direction, and has a locking surface 22 along the radial direction at the inner end in the width direction. Yes. When the extending portion 14 is inserted into the track space 11, the locking portion 21 elastically enters the stepped locking receiving portion 68 that is recessed at both axial ends of the inner peripheral surface of the roller 66. The locking surface 22 of the locking portion 21 faces the stepped surface 69 of the locking receiving portion 68 so as to be in contact with the stepped surface 69. As a result, the retainer 13 is held in a state in which the retainer 13 is restricted by the roller 66.

  By the way, when the rocker arm 60 is assembled to the cylinder head, as shown in FIG. 4, both sides in the width direction of the shaft portion 65 are blocked by the blocking walls 95, and the shaft portion 65 is reliably prevented from coming out of the rocker arm 60. Therefore, it is sufficient that the above-described retaining action by the locking portion 21 functions until the assembly of the rocker arm 60 is completed. In view of this point, in the case of the present embodiment, the locking portions 21 are provided at two places on both ends of the extending portion 14 in the extending direction. It is also possible to simply provide the locking portion 21 at one arbitrary position of 14. Of course, it does not deny that three or more locking portions 21 are provided in the extending portion 14.

  The molding resin for the cage 13 includes polyamides such as aromatic polyamide, polyamide 46, polyamide 6 and polyamide 66, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyacetal (POM), polytetrafluoro. A fluororesin such as ethylene (PTFE) can be suitably used. Moreover, what mixed reinforcing materials, such as glass fiber and carbon fiber, with these resin can be used, More preferably, 5-30 weight% of glass fiber or carbon fiber is mixed with a polyamide resin, and a bending elastic modulus. Is preferably 2000 to 5000 MPa. If it is this range, the softness | flexibility which the extension part 14 can deform | transform from a linear state to a circular arc state is ensured, and predetermined | prescribed elasticity and rigidity can be obtained.

  The cage 13 is formed by cutting a long member L (see FIG. 3) extending linearly at an appropriate position in the middle of the extension. At this time, the long member L is cut at a position corresponding to the notch 17 so as to cross the pocket 16, and both ends of the extended portion 14 of the formed cage 13 are configured to divide the notch 17. (See FIG. 2).

Next, a procedure for assembling the rolling bearing 10 of this embodiment will be described.
When holding the needle 12 in the cage 13, when the extending portion 14 is in a straight line state, the needle 12 is inserted into the pocket 16 of the cage 13, and then the roller 66 is placed in an end circular arc state. When the extension portion 14 is in an arcuate state, the needle 12 is inserted into the pocket 16 of the retainer 13, and thereafter or prior to that, the retainer 13 is annularly end-ended. There is a method of incorporating into the orbit space 11 as it is, and any method may be adopted.

  In the process in which the extended portion 14 is displaced from the linear state to the circular arc state, the opening size of the notch portion 17 and the pocket 16 (the opening size in the extending direction of the extended portion 14) is gradually narrowed on the inner diameter side which is the inner side of the bending. At the same time, the inner restricting portions 18 facing the pockets 16 approach each other so that the needle 12 can be pulled out in the inner diameter direction to a position where it can be restricted. Therefore, when the extending portion 14 is in a straight line state, the wrap allowance between the needle 12 accommodated in the pocket 16 and the inner restricting portion 18 can be reduced or eliminated, and the protruding amount of the inner restricting portion 18 can be suppressed to be small. it can.

  When the cage 13 is incorporated in the orbital space 11, the extending portion 14 is arranged in an arc shape, and both ends of the extending portion 14 are spaced in the circumferential direction (hereinafter referred to as a divided space DS (see FIG. 2)). They are arranged facing each other. Thus, the total length of the extending portion 14 (the length in the extending direction from one end to the other end) is set to be shorter than the entire circumferential length of the orbital space 11 by the circumferential length of the divided space DS. Yes. For this reason, it is not necessary to make the extension part 14, the full length, and the entire circumference of the orbit space 11 coincide with each other, and the dimension management of the extension part 14 can be performed roughly.

  Each needle 12 is accommodated in the pocket 16 and arranged side by side in the orbital space 11 with a certain interval except for the position corresponding to the dividing space DS. When the roller 66 rotates, each needle 12 rolls between the inner peripheral surface of the roller 66 and the outer peripheral surface of the shaft portion 65, thereby exhibiting a bearing function. In the case of the present embodiment, as shown in FIG. 2, the structure is such that one needle 12 is missing in the circumferential direction in the divided space DS. However, as long as the bearing function is not hindered, the divided space DS is used. The structure may be such that two or more needles 12 are missing in the circumferential direction.

  In the case of the present embodiment, the cage 13 can be used as it is for a bearing device (not limited to the rocker arm) different from the above. For example, when the inner diameter of the roller of the rocker arm is larger than the above and the entire circumference of the track space is longer than the above, the dividing space DS formed between both ends of the extending portion 14 is more circumferential than the above. The cage 13 is incorporated into the orbital space in a state expanded in the direction. On the other hand, for example, when the inner diameter of the roller of the rocker arm is smaller than the above and the entire circumference of the track space is shorter than the above, the dividing space DS formed between both ends of the extending portion 14 is as described above. Also, the cage 13 is incorporated in the orbital space in a state of being reduced in the circumferential direction.

  Thus, according to the present embodiment, even if the diameter of the orbital circle of the needle 12 is changed to any state of expansion or contraction, the extending portion 14 is expanded or contracted to a diameter corresponding to the changed diameter. Thus, since the cage 13 is deformed to a size that can be accommodated in the orbital space 11, it is possible to flexibly cope with a change in the diameter dimension. Therefore, it is possible to cover a plurality of types of bearing devices with a single cage 13, and there is no need to prepare a dedicated cage for each bearing device. As a result, the versatility is excellent and the productivity can be improved. In particular, in the case of the present embodiment, the retainer 13 is easily adjusted to a desired length by cutting the elongated member L extending in a straight line, so that the productivity can be further improved.

<Other embodiments>
Other embodiments will be briefly described below.
(1) The inner member may be configured as an annular inner ring, and the outer member may be configured as an annular outer ring. For example, when this is applied to the above-described embodiment, the outer ring can be fitted on the inner circumference side of the roller, and the inner ring can be fitted on the outer circumference side of the shaft portion.
(2) The extending portion may be brazed in advance so as to maintain an annular shape.
(3) The extending portion may be substantially inelastic.
(4) The outer restricting portion may be omitted from the cage.
(5) The cage may be made of metal as long as it does not interfere.
(6) The present invention is not limited to a rocker arm, and can be applied, for example, as a rolling bearing for an oil pump or a balance shaft, and can be widely applied to other bearing devices.

DESCRIPTION OF SYMBOLS 10 ... Rolling bearing 11 ... Orbit space 12 ... Needle (rolling element)
DESCRIPTION OF SYMBOLS 13 ... Cage 14 ... Extension part 15 ... Connection part 16 ... Pocket 17 ... Notch part 18 ... Inner side control part 60 ... Rocker arm 65 ... Shaft part (inner member)
66. Roller (outer member)

Claims (6)

A rolling bearing comprising a plurality of rolling elements arranged in an annular raceway space formed between an outer member and an inner member, and a cage that holds the rolling elements in a rollable manner,
The retainer extends in the direction in which the rolling elements are arranged in a state in which the rolling elements are accommodated, and is arranged in an end ring shape so as to extend along the circumferential direction of the orbital space, and has an extending portion that can expand and contract the diameter. A rolling bearing characterized by having.   The rolling bearing according to claim 1, wherein the extending portion is displaced from a linear state extending linearly into an arc state bent in an arc shape along a circumferential direction of the orbital space.   The part which becomes an inner peripheral surface in the circular arc state of the extending portion is provided with a plurality of notches that are the cause of bending from the linear state to the circular arc state with an interval. Item 2. A rolling bearing according to Item 2.   The extending portions are arranged to face each other in pairs in the axial direction of the rolling elements via a plurality of connecting portions, and a pocket for accommodating the rolling elements is defined by the extending portions and the connecting portions, The notch portion communicates with the pocket, and the adjacent connecting portion is provided with an inner restricting portion for restricting the rolling element from coming out in the inner diameter direction at a position near the inner diameter facing the pocket. 4. The rolling bearing according to claim 3, wherein   The rolling bearing according to claim 3 or 4, wherein both ends of the extension part are set at the formation part of the notch part. The adjacent connecting portion is provided with an outer restricting portion that restricts the rolling element from coming off in the outer diameter direction at a position near the outer diameter facing the pocket,
The center of the pocket communicating with the notch serves as a fulcrum for bending into the arc state, and in the arc state, the rolling element can roll with a clearance between the outer restricting portion and the inner restricting portion. The rolling bearing according to claim 4 or 5, wherein the rolling bearing is held.

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