JP2019039557A - bearing - Google Patents

Abstract

To attain further performance improvement of a bearing.SOLUTION: A bearing comprises a plurality of columnar needle rollers 13, and a holder 14 holding the needle rollers 13 so as to align them cylindrically in parallel with an axis direction, wherein on an inner periphery of a cylinder formed by the needle rollers 13, a pin roller is supported. The holder 14 has two rings 17, and a plurality of bridge parts 18 bridging an interval between the two rings 17, wherein between two adjacent bridge parts 18, some needle rollers 13 are housed and held. Consequently, a bearing 1 can attain further performance improvement.SELECTED DRAWING: Figure 4

Description

  The present disclosure relates to bearings.

2. Description of the Related Art Conventionally, for example, a bearing that supports a pin roller in a pin roller type pinion includes a plurality of needle rollers described below and a cage that holds these needle rollers.
That is, the needle roller is, for example, a metal cylindrical body, and the cage holds the plurality of needle rollers so as to be aligned in the axial direction and in a cylindrical shape. And a pin roller is supported from the outer peripheral side by the inner periphery of the cylinder formed of a plurality of needle rollers.

JP 2013-36488 A

  In such a bearing, further improvement in performance is an issue, and countermeasures are required.

The bearing according to the present disclosure supports a target component that rotates and reciprocates, and holds a plurality of columnar needle rollers and a plurality of needle rollers so as to be aligned in a cylinder and parallel to the axial direction of the target component. And a pin roller is supported by an inner periphery of a cylinder formed by a plurality of needle rollers. The cage includes two rings and a plurality of bridging portions that bridge between the two rings, and holds and holds a plurality of needle rollers between two adjacent bridging portions.
Thereby, the bearing of this indication has the effect that the further performance improvement can be achieved potentially.

(Example 1) which is a perspective view of a drive device. (Example 1) which is a disassembled perspective view of a pinion. It is a disassembled perspective view which shows a bearing with a pin roller (Example 1). (A) is a disassembled perspective view which shows a holder | retainer and a needle roller, (b) is a perspective view which shows the holder | retainer equipped with the needle roller (Example 1). (Example 1) which is sectional drawing of a bearing. (Example 1) which is VI-VI sectional drawing of FIG. (Example 1) which is the elements on larger scale of FIG. (Example 2) which is the elements on larger scale which show the principal part of a bearing. (Example 2) which is a perspective view of a retainer.

  The mode for carrying out the present disclosure will be described in detail with reference to the following examples.

[Configuration of Example 1]
The bearing 1 according to the first embodiment is incorporated in a pinion 3 of a rack and pinion type driving device 2.
First, the overall configuration of the driving device 2 will be described with reference to FIG.
The drive device 2 moves various articles | goods by moving the housing 4 which accommodates the pinion 3 along two rails 5A and 5B, for example. The rack 6 is provided between the rails 5 </ b> A and 5 </ b> B, and the pinion 3 is accommodated in the housing 4 so that the axial direction R of its rotation is perpendicular to the longitudinal direction M of the rack 6.

  Here, the housing 4 has, for example, a ceiling portion 4a that covers the pinion 3 from above, and outer wall portions 4A and 4B that are slidably fitted to the rails 5A and 5B, respectively, and are formed in a gate shape. Yes. The rails 5A and 5B each have a T-shaped cross section, and the outer wall portions 4A and 4B are fitted to the rails 5A and 5B from the outside on the base end side opposite to the ceiling portion 4a. Of the rotating shaft 7 of the pinion 3, one end portion 7A on one end side in the axial direction R and the other end portion 7B on the other end side in the axial direction R are rotatably supported by the outer wall portions 4A and 4B, respectively. Yes. The rotating shaft 7 is rotationally driven by a predetermined electric motor (not shown).

  Then, for example, when the pinion 3 receives torque in the rotation direction F shown in FIG. 1, the pinion 3 advances in the longitudinal direction M while rotating in the rotation direction F while meshing its teeth with the teeth 6 a of the rack 6. The tooth portion 6a has a profile that follows a predetermined cycloid curve.

Next, the whole structure of the pinion 3 is demonstrated using FIG. 2 and FIG.
The pinion 3 includes a plurality of cylindrical and metal pin rollers 9 and two supports 10A and 10B that support the plurality of pin rollers 9 at both ends in the axial direction R so as to be arranged in parallel and in a cylindrical shape with the axial direction R. With. The bearing 1 is incorporated in the supports 10A and 10B. And the drive device 2 advances the pinion 3 to the longitudinal direction M by rotationally driving the pinion 3 while fitting each pin roller 9 on the tooth bottom of the tooth part 6a.

Here, the support bodies 10A and 10B are provided in an annular shape, for example, and circular holes 11A and 11B for receiving the bearings 1 are provided at equal angular intervals as the pin rollers 9, respectively. The circular holes 11A and 11B are both provided on the outer peripheral sides of the supports 10A and 10B.
Then, the support bodies 10A and 10B are arranged so that the circular holes 11A and 11B face each other, and the pin roller 9 is assembled so as to be bridged between the support bodies 10A and 10B.

  That is, one end portion 9A on the one end side in the axial direction R of the pin roller 9 is rotatably supported in the circular hole 11A via the bearing 1, and the other end portion 9B on the other end side is a circular hole via the bearing 1. 11B is rotatably supported in 11B.

Next, the bearing 1 will be described with reference to FIGS.
The bearing 1 is held in the circular holes 11A and 11B and supports the one end 9A and the other end 9B of the pin roller 9 from the outer peripheral side. The bearing 1 has a plurality of needle rollers 13, a retainer 14, and a housing 15 described below (see FIG. 3).

First, the needle roller 13 is a metal cylinder.
Next, the retainer 14 retains the plurality of needle rollers 13 so as to be aligned in the axial direction and in a cylindrical shape. The pin roller 9 is supported on the inner periphery of a cylinder formed by the plurality of needle rollers 13.

  The cage 14 has two rings 17 and a plurality of bridging portions 18 that bridge between the two rings 17, and the needle roller 13 is disposed between two bridging portions 18 adjacent in the circumferential direction. Multiple pieces are accommodated and held rotatably. Note that the number of needle rollers 13 held between the bridging portions 18 is preferably 2 or 3.

  Moreover, the both ends of the axial direction among the bridge | crosslinking parts 18 are the overhang | projection parts 19 projecting to the outer peripheral side. Further, the overhanging portion 19 has a cylindrical surface 20 having a diameter equivalent to the diameter of the needle roller 13 on both sides in the circumferential direction of the overhanging portion 19, and the cylindrical surface 20 supports the end portion of the needle roller 13 to be rotatable. . The end surface of the needle roller 13 in the axial direction R is in contact with the ring 17. The cage 14 is made of resin.

The housing 15 includes a cylindrical portion 26 and a closing portion 27 that closes one end side of the cylindrical portion 26, and is provided as a metal bottomed cylindrical body. The housing 15 accommodates the retainer 14 that is firmly fitted in the circular holes 11A and 11B and holds the needle roller 13 on its inner peripheral side. The retainer 14 holding the needle roller 13 is rotatable as a whole on the inner periphery of the cylindrical portion 26, and each needle roller 13 includes an inner peripheral wall of the cylindrical portion 26 and an outer peripheral surface of the pin roller 9. It comes to slidably contact with.
An oil seal 28 is attached to the inner periphery near the opening of the housing 15.

[Effect of Example 1]
The bearing 1 according to the first embodiment includes a plurality of columnar needle rollers 13 and a retainer 14 that holds the plurality of needle rollers 13 so as to be parallel to the axial direction and arranged in a cylindrical shape. The pin roller 9 is supported by the inner periphery of the formed cylinder. The retainer 14 includes two rings 17 and a plurality of bridging portions 18 that bridge between the two rings 17, and a plurality of needle rollers 13 between two adjacent bridging portions 18. Hold and hold.

Thereby, the bearing 1 becomes a structure close to a “full roller” that does not have the cage 14, and further performance improvement can be achieved.
That is, it can withstand a greater radial load with a smaller physique.
Furthermore, since it is possible to suppress the inclination of the individual needle rollers 13 without arranging the bridging portions 18 between all the needle rollers 13, it is possible to eliminate the problems that occur when the needle rollers 13 are inclined. it can.

  For example, it is possible to suppress the temperature from rising due to the friction caused by the contact between the needle rollers 13, and the needle roller 13 itself from being worn out or the lubricating grease from being deteriorated. Moreover, the vibration and noise accompanying the contact between the needle rollers 13 can be suppressed. Further, it is possible to suppress a decrease in efficiency due to the inclination of the needle roller 13.

Moreover, the both ends of the axial direction R among the bridge | crosslinking parts 18 are the overhang | projection parts 19 which protrude on the outer peripheral side.
As a result, a grease filling region can be ensured between the two overhanging portions 19 and on the outer peripheral side of the bridging portion 18.
The end surface of the needle roller 13 in the axial direction R is in contact with the ring 17.
Thereby, the inclination of the needle roller 13 can be further suppressed.

The cage 14 is made of resin.
Thereby, the freedom degree of shaping | molding can be raised compared with the case where the holder | retainer 14 is made from metal. For this reason, for example, the clearance between the needle rollers 13 can be narrowed by making the bridging portion 18 as thin as possible. Moreover, compared with the case where the cage 14 is made of metal, wear and grease deterioration due to contact between the needle roller 13 and the cage 14 can be suppressed.

[Example 2]
According to the bearing 1 of the second embodiment, as shown in FIG. 8, a resin retainer 30 is sandwiched between needle rollers 13 adjacent to each other in the circumferential direction between two adjacent bridging portions 18.
For example, as illustrated in FIG. 9, the retainer 30 is provided as a pillar, and the retainer 30 is provided so that two side surfaces 30 a that are recessed in a cylindrical shape are back to back. The retainer 30 is incorporated in the bearing 1 so that its own axial direction is parallel to the axial direction of the bearing 1. Further, the two side surfaces 30a have substantially the same radius of curvature as the radius of the needle roller 13, and the needle roller 13 is accommodated in a recess formed by each side surface 30a. The minimum value t of the distance between the two side surfaces 30a is set to 0.1 mm or more and 0.5 mm or less.

Thereby, according to the bearing 1 of Example 2, since the needle rollers 13 are not in direct contact with each other, sliding contact between metal surfaces having high friction can be avoided. For this reason, according to the bearing 1 of Example 2, even if the pin roller 9 rotates at high speed, it can endure a large radial load and can exhibit high performance.
Note that the resin material of the retainer 30 may be the same resin material as that of the cage 14, or may be an oil lubricant-containing resin. When an oil lubricant-containing resin is employed, the use of grease can be stopped.

[Modification]
Various modifications of the present invention can be considered without departing from the gist thereof.
For example, the drive device 2 of the embodiment drives the pinion 3 along the rack 6 by rotationally driving the pinion 3. However, the pinion 3 is rotationally driven while the position of the pinion 3 is fixed, and the rack 6 is moved. The drive device may be advanced, and the pinion 3 may be engaged with a gear other than the rack 6 to constitute a drive device other than the rack-and-pinion type.

In addition, the bearing 1 of the embodiment supports the pin roller 9 of the pinion 3, but the parts supported by the bearing 1 are not limited to the pin roller 9, and any parts can be used as long as they rotate or reciprocate. You may support.
Further, according to the bearing 1 of the embodiment, the cage 14 is made of resin, but may be made of metal.

DESCRIPTION OF SYMBOLS 1 Bearing 9 Pin roller (target part) 13 Needle roller 14 Cage 17 Ring 18 Bridging part R Axial direction

Bearing of the present disclosure is intended to support the target part you rotation, a cylindrical plurality of needle rollers, holding for holding to be aligned in parallel and cylindrical multiple needle rollers in the axial direction of the target component And a pin roller is supported by an inner periphery of a cylinder formed by a plurality of needle rollers. The cage includes two rings and a plurality of bridging portions that bridge between the two rings, and holds and holds a plurality of needle rollers between two adjacent bridging portions. Further, both ends in the axial direction of the bridging portion are overhanging portions projecting to the outer peripheral side, and the overhanging portions are provided with cylindrical surfaces having a diameter equivalent to the diameter of the needle roller on both sides in the circumferential direction. The end of the needle roller is rotatably supported by the cylindrical surface.
Thereby, the bearing of this indication has the effect that the further performance improvement can be achieved potentially.

Further, the bearing 1 of the embodiment has been to support the pin roller 9 of the pinion 3, parts for supporting the bearing 1 is not limited to the pin roller 9, if a component you rotation, supporting any component May be.
Further, according to the bearing 1 of the embodiment, the cage 14 is made of resin, but may be made of metal.

DESCRIPTION OF SYMBOLS 1 Bearing 9 Pin roller (target part) 13 Needle roller 14 Cage 17 Ring 18 Bridging part 19 Overhang part 20 Cylindrical surface R Axial direction

Claims (5)

A bearing (1) for supporting a rotating or reciprocating target part (9),
A plurality of cylindrical needle rollers (13);
A holder (14) for holding the plurality of needle rollers so as to be aligned in parallel and in a cylindrical shape in the axial direction of the target part;
Supporting the target part on the inner periphery of a cylinder formed by the plurality of needle rollers,
The cage is
It has two rings (17) and a plurality of bridging portions (18) bridging between the two rings, and holds and holds a plurality of needle rollers between two adjacent bridging portions. A bearing characterized by. The bearing according to claim 1,
Of the bridging portion, both ends in the axial direction are projecting portions (19) projecting to the outer peripheral side. The bearing according to claim 1 or claim 2,
The bearing according to claim 1, wherein an end surface of the needle roller in the axial direction is in contact with the ring. The bearing according to any one of claims 1 to 3,
The bearing is made of resin. In the bearing according to any one of claims 1 to 4,
A bearing comprising a resin retainer (30) sandwiched between needle rollers adjacent to each other between two adjacent bridging portions.

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