JP2007192267A

JP2007192267A - Retainer for radial needle bearing and radial needle bearing

Info

Publication number: JP2007192267A
Application number: JP2006009493A
Authority: JP
Inventors: Kenichi Shibazaki; 健一柴崎
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 2006-01-18
Filing date: 2006-01-18
Publication date: 2007-08-02

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure capable of reducing the wear of the rolling surface of each needle and the wear of the inner surface of each pocket 11 even when the axial displacement of a radial needle bearing 1a is restricted by using the outer faces 12a, 12a of rim parts 9a, 9a forming a retainer 6a. <P>SOLUTION: The outer surfaces 12a, 12a of the rim parts 9a, 9a are formed in a partially tapered projecting inclined surface inclined in the direction that the axial thickness of each rim part 9a is increased toward the inner diameter side. Only the inner peripheral edge portion 14 of the outer surface 12a is brought into slidable contact with a step surface 13 formed in a rotating shaft to restrict the axial displacement of the radial needle bearing 1a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、各種回転支持装置に組み込んで、ハウジング等の固定部分の内側に回転軸を支承する為のラジアルニードル軸受及びこのラジアルニードル軸受に組み込むラジアルニードル軸受用保持器の改良に関する。 The present invention relates to an improvement in a radial needle bearing that is incorporated in various rotation support devices and supports a rotation shaft inside a fixed portion such as a housing, and a radial needle bearing retainer that is incorporated in the radial needle bearing.

自動車用変速機や各種機械装置の回転支持部のうち、大きなラジアル荷重が加わる部分にはラジアルニードル軸受が組み込まれている（例えば特許文献１、２等参照）。図４〜５は、従来から広く知られた従来構造のラジアルニードル軸受１を組み込んで構成する、回転支持部の１例を示している。例えば自動車用変速機用の歯車伝達機構を構成する伝達軸、或は、工作機械の主軸等の様に、駆動源により回転駆動される回転軸２と、この回転軸２の周囲に配置されたハウジング３（或は歯車）との間の環状空間４内には、ラジアルニードル軸受１を配置して、上記回転軸２をこのハウジング３の内側に回転自在に（或は回転軸と歯車との相対回転を自在に）支持している。このラジアルニードル軸受１は、複数本のニードル５を、保持器６により転動自在に保持すると共に、上記回転軸２の外周面を円筒状の内輪軌道７とし、上記ハウジング３の内周面を円筒状の外輪軌道８として、上記各ニードル５の転動面を、これら内輪軌道７及び外輪軌道８に転がり接触させている。 A radial needle bearing is incorporated in a portion to which a large radial load is applied among rotation support portions of an automobile transmission or various mechanical devices (see, for example, Patent Documents 1 and 2). FIGS. 4 to 5 show an example of a rotation support portion that is configured by incorporating a conventional radial needle bearing 1 having a well-known structure. For example, a transmission shaft constituting a gear transmission mechanism for an automobile transmission or a main shaft of a machine tool, etc., and a rotary shaft 2 driven to rotate by a driving source, and arranged around the rotary shaft 2 A radial needle bearing 1 is arranged in an annular space 4 between the housing 3 (or gear) and the rotary shaft 2 can be rotated inside the housing 3 (or between the rotary shaft and the gear). Supports relative rotation freely. The radial needle bearing 1 holds a plurality of needles 5 by a cage 6 so as to be freely rotatable, and the outer peripheral surface of the rotary shaft 2 is a cylindrical inner ring raceway 7, and the inner peripheral surface of the housing 3 is As the cylindrical outer ring raceway 8, the rolling surface of each needle 5 is brought into rolling contact with the inner ring raceway 7 and the outer ring raceway 8.

上記ラジアルニードル軸受１を構成する上記保持器６は、例えば特許文献３等に記載され、図６に示す様に、合成樹脂を射出成形する事により、或は銅系合金等の金属材料に削り加工を施す事により構成し、軸方向（図６の左右方向）に間隔をあけて配置した、それぞれが円環状である１対のリム部９、９と、複数本の柱部１０、１０とを備える。これら各柱部１０、１０は、円周方向に亙って間欠的に配置され、それぞれの両端部を上記両リム部９、９の互いに対向する内側面に連続させている。そして、円周方向に隣り合う上記各柱部１０、１０の円周方向両側面と、上記両リム部９、９の互いに対向する内側面とにより四周を囲まれた部分を、それぞれ上記各ニードル５を転動自在に保持する為のポケット１１、１１としている。 The cage 6 constituting the radial needle bearing 1 is described in, for example, Patent Document 3 and the like, and is cut into a metal material such as a copper alloy or the like by injection molding a synthetic resin as shown in FIG. A pair of rim portions 9 and 9 each having an annular shape, and a plurality of column portions 10 and 10, which are configured by machining and arranged at intervals in the axial direction (left and right direction in FIG. 6) Is provided. These column portions 10 and 10 are intermittently arranged in the circumferential direction, and both end portions thereof are made to be continuous with the mutually opposing inner side surfaces of the rim portions 9 and 9. Then, the portions surrounded by the four circumferences by both circumferential side surfaces of the column parts 10 and 10 adjacent to each other in the circumferential direction and the inner side surfaces of the rim parts 9 and 9 facing each other are respectively connected to the needles. 5 and 11 are pockets 11 and 11 for holding the roll 5 freely.

又、上記ラジアルニードル軸受１を上記環状空間４内に組み込む際には、上記保持器６を構成する一方（図４の右側）のリム部９の外側面１２を、上記回転軸２の外周面に設けた段差面１３に全周に亙り近接対向させる。この為、回転支持部にアキシアル方向の荷重が加わり、図４に示す様に、上記ラジアルニードル軸受１が上記回転軸２に対して矢印イ方向に相対変位した状態では、上記外側面１２を上記段差面１３に摺接（滑り接触）させて、上記ラジアルニードル軸受１がそれ以上軸方向に変位する事を阻止する。又、他方の（図４の左側）のリム部９の外側面１２に就いても同様に、図示しない他の部材（例えば回転軸２に外嵌した部材或いはハウジング３の一部等）に近接対向させて、上記ラジアルニードル軸受１が上記回転軸２に対して上記矢印イとは反対方向に過大に変位する事を阻止する様にしている。 Further, when the radial needle bearing 1 is incorporated into the annular space 4, the outer surface 12 of the rim portion 9 that constitutes the cage 6 (the right side in FIG. 4) is connected to the outer peripheral surface of the rotating shaft 2. The entire surface of the step surface 13 is set to face the step surface 13. For this reason, a load in the axial direction is applied to the rotation support portion, and when the radial needle bearing 1 is relatively displaced in the direction of the arrow A with respect to the rotation shaft 2 as shown in FIG. The radial needle bearing 1 is prevented from being displaced further in the axial direction by sliding contact (sliding contact) with the step surface 13. Similarly, the outer surface 12 of the other rim portion 9 (left side in FIG. 4) is also close to another member (not shown) (for example, a member externally fitted to the rotating shaft 2 or a part of the housing 3). The radial needle bearing 1 is opposed to the rotary shaft 2 from being excessively displaced in the direction opposite to the arrow A.

但し、上述の様に、保持器６を構成する各リム部９、９の外側面１２、１２を利用して、ラジアルニードル軸受１（を構成する各ニードル５及び保持器６）の軸方向に関する変位規制を図る場合には、以下の様な問題を生じる可能性がある。即ち、運転時に於ける上記保持器６の回転速度と、上記回転軸２の回転速度（或いは外側面１２をハウジング３の一部に摺接させる場合には、このハウジング３の回転速度）とは通常一致しない。この為、上記外側面１２を上記段差面１３（或いはハウジング３の一部等）に摺接させる際には、上記保持器６に、この保持器６の回転方向に関する（正若しくは負の）摩擦力が加わる。又、従来構造の保持器６の外側面１２は、上記段差面１３に対しほぼ平行な平坦面としている為、これら両面１２、１３が摺接する際には、上記外側面１２のうちの外径側部分にも摩擦力が加わる（図５の矢印ロ参照）。この為、上記保持器６の回転中心Ｏから摩擦力の作用点（摺接部の径方向位置）Ｐ₀ までの距離Ｌ₀ は大きくなり、上記保持器６には大きな摩擦トルク（＝摩擦力×保持器の回転中心から摩擦力の作用点までの距離）が作用する。この為、本来ほぼ同程度の速度になる、上記保持器６の回転速度と上記各ニードル５の公転速度との間に速度差を生じさせる。この結果、これら各ニードル５の転動面と前記各ポケット１１内面（主に前記各柱部１０、１０の円周方向側面）とが強く摺接し合う様になり、これら各面を早期に摩耗させる可能性がある。そして、上記ラジアルニードル軸受１の動トルクが著しく大きくなったり、回転支持部の動力損失が大きくなると言った問題を引き起こす可能性がある。 However, as described above, the outer side surfaces 12 and 12 of the rim portions 9 and 9 constituting the cage 6 are used to relate to the axial direction of the radial needle bearing 1 (the needles 5 and the cage 6 constituting the radial needle bearing 1). When the displacement is controlled, the following problems may occur. That is, the rotational speed of the cage 6 during operation and the rotational speed of the rotary shaft 2 (or the rotational speed of the housing 3 when the outer surface 12 is brought into sliding contact with a part of the housing 3). Usually does not match. For this reason, when the outer surface 12 is brought into sliding contact with the stepped surface 13 (or a part of the housing 3 or the like), the cage 6 is subjected to friction (positive or negative) in the rotational direction of the cage 6. Power is added. Further, since the outer surface 12 of the cage 6 having a conventional structure is a flat surface substantially parallel to the step surface 13, when the both surfaces 12, 13 are in sliding contact with each other, the outer diameter of the outer surface 12 is increased. A frictional force is also applied to the side portion (see arrow B in FIG. 5). For this reason, the distance L ₀ from the rotation center O of the cage 6 to the point of application of frictional force (the radial position of the sliding contact portion) P ₀ becomes large, and the cage 6 has a large friction torque (= frictional force). X Distance from the center of rotation of the cage to the point of application of the frictional force). For this reason, a speed difference is generated between the rotational speed of the cage 6 and the revolution speed of the needles 5 which are essentially the same speed. As a result, the rolling surfaces of the needles 5 and the inner surfaces of the pockets 11 (mainly the circumferential side surfaces of the column parts 10 and 10) come into slidable contact with each other, and these surfaces are worn quickly. There is a possibility to make it. And the dynamic torque of the said radial needle bearing 1 may become remarkably large, and the problem that the power loss of a rotation support part becomes large may be caused.

特開平６−２１３２３０号公報JP-A-6-213230 特開平６−２９４４１８号公報JP-A-6-294418 特開平１０−１４１３７６号公報Japanese Patent Laid-Open No. 10-141376

本発明は、上述の様な事情に鑑み、ラジアルニードル軸受の軸方向に関する変位規制を、保持器を構成するリム部の外側面を利用して図る場合にも、各ニードルの転動面や各ポケット内面に生じる摩耗を低減できる構造を実現すべく発明したものである。 In view of the circumstances as described above, the present invention also provides a rolling surface for each needle and each of the rolling surfaces of the needles, even when the displacement control in the axial direction of the radial needle bearing is intended using the outer surface of the rim part constituting the cage. The invention was invented to realize a structure capable of reducing wear generated on the pocket inner surface.

本発明のラジアルニードル軸受用保持器及びラジアルニードル軸受のうち、請求項１に記載したラジアルニードル軸受用保持器は、軸方向に間隔をあけて互いに同心に配置された、それぞれが円環状である１対のリム部と、これら両リム部同士の間に掛け渡された複数本の柱部とを備える。又、これら両リム部と円周方向に隣り合う柱部とにより四周を囲まれた部分を、それぞれニードルを転動自在に保持する為のポケットとしている。そして、上記リム部の外側面を、この外側面に隣接して配置された他の部材に摺接させる事により、軸方向に関する変位規制を図る状態で使用する。
特に、本発明のラジアルニードル軸受用保持器に於いては、上記リム部の外側面を、内径側部分を外径側部分に対して軸方向に突出させた形状とする事により、このリム部の外側面のうち上記内径側部分のみを、上記他の部材に摺接可能としている。 Of the radial needle bearing retainer and the radial needle bearing according to the present invention, the radial needle bearing retainer described in claim 1 is arranged concentrically with an interval in the axial direction, and each is annular. A pair of rim portions and a plurality of pillar portions spanned between the two rim portions are provided. Further, the portions surrounded by the four rims by both the rim portions and the column portions adjacent to each other in the circumferential direction serve as pockets for holding the needles in a freely rollable manner. And it uses in the state which aims at the displacement control regarding an axial direction by making the outer side surface of the said rim | limb part slide-contact with the other member arrange | positioned adjacent to this outer side surface.
In particular, in the radial needle bearing retainer of the present invention, the outer surface of the rim portion is shaped so that the inner diameter side portion projects in the axial direction with respect to the outer diameter side portion. Of the outer surface, only the inner diameter side portion can be slidably contacted with the other member.

又、請求項２に記載したラジアルニードル軸受は、互いに同心に配置された、それぞれが円筒状である内輪軌道及び外輪軌道と、これら内輪軌道と外輪軌道との間に転動自在に設けられた複数本のニードルと、これら各ニードルを保持する保持器とを備える。
特に、本発明のラジアルニードル軸受に於いては、上記保持器が、請求項１に記載したラジアルニードル軸受用保持器である。 Further, the radial needle bearing described in claim 2 is arranged concentrically with each other, and is provided with a cylindrical inner ring raceway and an outer ring raceway, and between the inner ring raceway and the outer ring raceway so as to be capable of rolling. A plurality of needles and a holder for holding each needle are provided.
In particular, in the radial needle bearing of the present invention, the cage is a radial needle bearing cage according to claim 1.

上述の様に構成する本発明によれば、ラジアルニードル軸受の軸方向に関する変位規制を、保持器を構成するリム部の外側面を利用して図る構造を採用した場合にも、各ニードルの転動面や各ポケット内面に生じる摩耗を低減する事ができる。即ち、本発明の場合には、ラジアルニードル軸受（を構成する各ニードル及び保持器）の軸方向に関する変位規制を、保持器を構成するリム部の外側面のうち、内径側部分のみを用いて行なう。この為、上記ラジアルニードル軸受の軸方向に関する変位規制を図る際に、上記保持器に加わる摩擦力の作用点（摺接部の径方向位置）を、この保持器の回転中心に近づける事ができる。この為、この保持器に作用する摩擦トルクを小さく抑える事ができて、この保持器の回転速度と各ニードルの公転速度との間に大きな速度差が生じる事を防止できる。この結果、各ニードルの転動面や各ポケット内面に生じる摩耗を低減できて、ラジアルニードル軸受の動トルクが著しく大きくなったり、回転支持部の動力損失が大きくなると言った問題が生じる事を防止できる。 According to the present invention configured as described above, even when a structure is adopted in which the displacement control in the axial direction of the radial needle bearing is performed using the outer surface of the rim portion that constitutes the cage, the rotation of each needle is performed. It is possible to reduce wear generated on the moving surface and the inner surface of each pocket. That is, in the case of the present invention, the displacement restriction in the axial direction of the radial needle bearing (each needle and the cage constituting the radial needle bearing) is restricted using only the inner diameter side portion of the outer surface of the rim portion constituting the cage. Do. For this reason, when aiming at displacement control in the axial direction of the radial needle bearing, the point of action of the frictional force applied to the cage (the radial position of the sliding contact portion) can be brought close to the rotation center of the cage. . For this reason, the friction torque acting on the cage can be kept small, and a large speed difference between the rotational speed of the cage and the revolution speed of each needle can be prevented. As a result, wear generated on the rolling surface of each needle and the inner surface of each pocket can be reduced, preventing problems such as the dynamic torque of the radial needle bearing being significantly increased and the power loss of the rotation support portion being increased. it can.

［実施の形態の第１例］
図１〜２は、請求項１、２に対応する、本発明の実施の形態の第１例を示している。尚、本例の特徴は、ラジアルニードル軸受１ａ（を構成する各ニードル５及び保持器６ａ）の軸方向に関する変位規制を図る為に利用する、この保持器６ａの軸方向端面（各リム部９ａの外側面１２ａ）の形状を工夫した点にある。上記ラジアルニードル軸受１ａの全体構造等、その他の部分の構造及び作用は、前述の図４〜６に示した従来構造の場合と同様である。この為、重複する図示並びに説明は省略若しくは簡略にして、以下、本例の特徴部分を中心に説明する。 [First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. The feature of this example is that the axial end face (each rim portion 9a) of the retainer 6a is used for restricting displacement in the axial direction of the radial needle bearing 1a (each needle 5 and retainer 6a). The shape of the outer surface 12a) is devised. The structure and operation of other parts such as the overall structure of the radial needle bearing 1a are the same as those of the conventional structure shown in FIGS. For this reason, overlapping illustrations and descriptions will be omitted or simplified, and the following description will focus on the features of this example.

本例の保持器６ａは、前述の図６に示した従来構造の場合と同様に、合成樹脂を射出成形する事により形成し、全体を円筒状としている。本例の場合には、この様な保持器６ａを構成する各リム部９ａ、９ａの外側面１２ａ、１２ａを、内径側に向かう程これら各リム部９ａの軸方向に関する厚さを大きくする方向に傾斜させた、部分円すい凸面状の傾斜面としている。そして、上記外側面１２ａの内周縁部分１４を、この外側面１２ａのうちの残部（径方向中間部分乃至外径側部分）に比べて軸方向に突出させた構成としている。 As in the case of the conventional structure shown in FIG. 6, the retainer 6a of this example is formed by injection molding synthetic resin, and has a cylindrical shape as a whole. In the case of this example, the outer surfaces 12a, 12a of the rim portions 9a, 9a constituting such a retainer 6a are increased in thickness in the axial direction of the rim portions 9a toward the inner diameter side. The inclined surface is a convex surface with a partial conical shape. And the inner peripheral edge part 14 of the said outer surface 12a is set as the structure protruded in the axial direction compared with the remainder (radial direction intermediate | middle part thru | or outer diameter side part) of this outer side surface 12a.

この様な保持器６ａは、ポケット１１内にそれぞれニードル５を保持してラジアルニードル軸受１ａを構成し、回転軸２とハウジング３との間の環状空間４内に組み込んで、この回転軸２をこのハウジング３の内側に回転自在に支持する。又、上記ラジアルニードル軸受１ａを上記環状空間４内に組み込む際には、上記保持器６ａを構成する一方（図１の右側）のリム部９ａの外側面１２ａのうち、その内周縁部分１４を、上記回転軸２に設けた段差面１３に全周に亙り近接対向させる。この為、回転支持部にアキシアル方向の荷重が加わり、図１に示す様に、上記ラジアルニードル軸受１ａが上記回転軸２に対して矢印ハ方向に相対変位した状態では、上記外側面１２ａのうちの内周縁部分１４を上記段差面１３に摺接させる。そして、上記ラジアルニードル軸受１ａ（を構成する各ニードル５及び保持器６ａ）がそれ以上軸方向に変位する事を阻止する。又、他方の（図１の左側）のリム部９ａに就いても同様に、外側面１２ａの内周縁部分１４を、図示しない他の部材（例えば回転軸２に外嵌した部材或いはハウジング３の一部等）に近接対向させて、上記ラジアルニードル軸受１ａが上記回転軸２に対して上記矢印ハとは反対方向に過大に変位する事を阻止している。従って、本例の場合にも、前述した従来構造の場合と同様に、ラジアルニードル軸受１ａの軸方向に関する変位規制を、保持器６ａを構成する各リム部９ａ、９ａの外側面１２ａ、１２ａを利用して行なう事ができる。 Such a retainer 6a forms a radial needle bearing 1a by holding the needles 5 in the pockets 11, and is incorporated in an annular space 4 between the rotating shaft 2 and the housing 3, so that the rotating shaft 2 is The housing 3 is rotatably supported. When the radial needle bearing 1a is incorporated into the annular space 4, the inner peripheral edge portion 14 of the outer surface 12a of one rim portion 9a (the right side in FIG. 1) constituting the retainer 6a is formed. The stepped surface 13 provided on the rotating shaft 2 is made to face and face the entire circumference. For this reason, an axial load is applied to the rotation support portion, and as shown in FIG. 1, the radial needle bearing 1a is displaced relative to the rotation shaft 2 in the direction of the arrow C. The inner peripheral edge portion 14 is brought into sliding contact with the stepped surface 13. The radial needle bearing 1a (each needle 5 and the cage 6a constituting the radial needle bearing 1a) is prevented from being displaced further in the axial direction. Similarly, with respect to the other rim portion 9a (left side in FIG. 1), the inner peripheral edge portion 14 of the outer surface 12a may be connected to another member (not shown) (for example, a member externally fitted to the rotary shaft 2 or the housing 3). The radial needle bearing 1a is prevented from being excessively displaced in the direction opposite to the arrow C with respect to the rotary shaft 2 in close proximity to each other. Therefore, also in the case of this example, as in the case of the above-described conventional structure, the displacement control in the axial direction of the radial needle bearing 1a is performed on the outer side surfaces 12a and 12a of the rim portions 9a and 9a constituting the cage 6a. You can use it.

特に本例の場合には、上記ラジアルニードル軸受１ａの軸方向に関する変位規制を、上記外側面１２ａのうちの内周縁部分１４のみを用いて行なう為、この外側面１２ａのうちの外径側部分には、前記図５に矢印ロで示した様な摩擦力が加わる事はない。即ち、上記外側面１２ａのうちで摺接部となる部分を、上記内周縁部分１４に限定できる。この為、上記保持器６ａの回転中心Ｏから摩擦力の作用点（摺接部の径方向位置）Ｐ₁ までの距離Ｌ₁ を、前述した従来構造の場合（Ｌ₀ ）に比べて短くする事ができる（Ｌ₁ ＜Ｌ₀ ）。従って、上記保持器６ａに作用する摩擦トルクを小さくする事ができて、この保持器６ａの回転速度と前記各ニードル５の公転速度との間に、大きな速度差が生じる事を防止できる。この結果、これら各ニードル５の転動面や前記各ポケット１１内面（主に前記各柱部１０、１０の円周方向側面）に生じる摩耗を低減できる。そして、上記ラジアルニードル軸受１ａの動トルクが著しく大きくなったり、回転支持部の動力損失が大きくなると言った問題が生じる事を防止できる。又、上記外側面１２ａと前記段差面１３との間に介在する油膜の面積も小さく抑えられるので、この油膜の剪断抵抗に基づく、上記保持器６ａの回転抵抗の増大も抑えられる。 Particularly in the case of this example, since the displacement restriction in the axial direction of the radial needle bearing 1a is performed using only the inner peripheral edge portion 14 of the outer surface 12a, the outer diameter side portion of the outer surface 12a. No frictional force as shown by the arrow B in FIG. 5 is applied. That is, the part which becomes a slidable contact part in the said outer side surface 12a can be limited to the said inner peripheral part 14. For this reason, the distance L ₁ from the rotation center O of the cage 6a to the point of application of the frictional force (the radial position of the sliding contact portion) P ₁ is made shorter than that in the case of the above-described conventional structure (L ₀ ). (L ₁ <L ₀ ). Therefore, the friction torque acting on the cage 6a can be reduced, and a large speed difference can be prevented from occurring between the rotational speed of the cage 6a and the revolution speed of each needle 5. As a result, it is possible to reduce wear generated on the rolling surfaces of the needles 5 and the inner surfaces of the pockets 11 (mainly the circumferential side surfaces of the column parts 10 and 10). And it can prevent that the dynamic torque of the said radial needle bearing 1a becomes large remarkably, or the problem that the power loss of a rotation support part becomes large arises. Further, since the area of the oil film interposed between the outer surface 12a and the stepped surface 13 is also suppressed, an increase in the rotational resistance of the cage 6a based on the shear resistance of the oil film can be suppressed.

尚、本例の構造によれば、上記段差面１３と上記外側面１２ａのうちの外径寄り部分との間には、軸方向に関する比較的大きな隙間が存在する。この為、上記内周縁部分１４と上記段差面１３との摺接部に多くの潤滑油を取り込む事が可能になり、互いに摺接するこれら内周縁部分１４と段差面１３が早期に摩耗する事を防止できる。又、上記保持器６ａを構成する合成樹脂としては、例えば自己潤滑性を有するポリアセタール又はポリアミド６６の他、耐熱性能に優れたポリアミド４６又はポリフェニレンサルファイド（ＰＰＳ）等を使用できる。但し、本例に使用する保持器６ａは、合成樹脂製に限定されず、銅、銅系合金、アルミニウム系合金等の金属材料製のものを使用する事もできる。
［実施の形態の第２例］ According to the structure of this example, there is a relatively large gap in the axial direction between the step surface 13 and the outer diameter portion of the outer surface 12a. For this reason, it becomes possible to take in a lot of lubricating oil into the sliding contact portion between the inner peripheral edge portion 14 and the stepped surface 13, and the inner peripheral edge portion 14 and the stepped surface 13 that are in sliding contact with each other can be worn at an early stage. Can be prevented. As the synthetic resin constituting the cage 6a, for example, polyacetal or polyamide 66 having self-lubricating property, polyamide 46 or polyphenylene sulfide (PPS) having excellent heat resistance can be used. However, the cage 6a used in this example is not limited to a synthetic resin, and a cage made of a metal material such as copper, a copper-based alloy, and an aluminum-based alloy can also be used.
[Second Example of Embodiment]

図３は、やはり請求項１、２に対応する、本発明の実施の形態の第２例を示している。本例の場合には、保持器６ｂを構成する各リム部９ｂの外側面１２ｂのうち、その内径側部分に環状凸部１５を形成して、この環状凸部１５を、この外側面１２ｂのうちの残部（径方向中間部分乃至外径側部分）よりも軸方向に突出させている。この様に構成する本例の場合も、上記外側面１２ｂのうちの上記環状凸部１５のみを用いて、ラジアルニードル軸受１ａ（図１、２参照）の軸方向に関する変位規制を図る事ができる。この為、上記保持器６ｂに加わる摩擦力の作用点を、この保持器６ｂの回転中心に近づけて、この保持器６ｂに作用する摩擦トルクを小さく抑える事ができる。この結果、本例の構造の場合も、各ニードル５の転動面や各ポケット１１内面（図１、２参照）に生じる摩耗を低減できる。そして、上記ラジアルニードル軸受１ａの動トルクが著しく大きくなったり、回転支持部の動力損失が大きくなると言った問題が生じる事を防止できる。その他の構成及び作用は、上述した実施の形態の第１例、及び、前述した従来構造の場合と同様である。 FIG. 3 shows a second example of the embodiment of the present invention, which also corresponds to claims 1 and 2. In the case of this example, an annular convex portion 15 is formed on the inner diameter side portion of the outer surface 12b of each rim portion 9b constituting the cage 6b, and the annular convex portion 15 is formed on the outer surface 12b. It protrudes in the axial direction from the remaining part (radial direction intermediate part or outer diameter side part). Also in the case of this example configured as described above, it is possible to restrict displacement in the axial direction of the radial needle bearing 1a (see FIGS. 1 and 2) using only the annular convex portion 15 of the outer surface 12b. . For this reason, the action point of the frictional force applied to the cage 6b can be brought close to the center of rotation of the cage 6b, so that the friction torque acting on the cage 6b can be kept small. As a result, also in the case of the structure of this example, the wear that occurs on the rolling surface of each needle 5 and the inner surface of each pocket 11 (see FIGS. 1 and 2) can be reduced. And it can prevent that the dynamic torque of the said radial needle bearing 1a becomes large remarkably, or the problem that the power loss of a rotation support part becomes large arises. Other configurations and operations are the same as those of the first example of the embodiment described above and the conventional structure described above.

本発明の実施の形態の第１例を示す、図４と同様の図。The figure similar to FIG. 4 which shows the 1st example of embodiment of this invention. 同じく、図５に対応する、図１のＡ−Ａ断面図。Similarly, AA sectional view of FIG. 1 corresponding to FIG. 同第２例を示す、図１のＢ部に相当する図。The figure which shows the 2nd example and corresponds to the B section of FIG. 従来構造のラジアルニードル軸受を組み込んだ回転支持部の１例を示す略断面図。The schematic sectional drawing which shows an example of the rotation support part incorporating the radial needle bearing of the conventional structure. 同じく、図４のＣ−Ｃ断面図。Similarly, CC sectional drawing of FIG. 同じく、従来構造の保持器の１例を示す略断面図。Similarly, it is a schematic sectional view showing an example of a cage having a conventional structure.

Explanation of symbols

１、１ａラジアルニードル軸受
２回転軸
３ハウジング
４環状空間
５ニードル
６、６ａ、６ｂ保持器
７内輪軌道
８外輪軌道
９、９ａ、９ｂリム部
１０柱部
１１ポケット
１２、１２ａ、１２ｂ外側面
１３段差面
１４内周縁部分
１５環状凸部 DESCRIPTION OF SYMBOLS 1, 1a Radial needle bearing 2 Rotating shaft 3 Housing 4 Annular space 5 Needle 6, 6a, 6b Cage 7 Inner ring raceway 8 Outer ring raceway 9, 9a, 9b Rim part 10 Column part 11 Pocket 12, 12a, 12b Outer side face 13 Step Surface 14 Inner peripheral edge 15 Annular convex

Claims

A pair of rim portions arranged in a concentric manner with an interval in the axial direction, each having an annular shape, and a plurality of pillar portions spanned between the two rim portions, A portion surrounded by the rim portion and a column portion adjacent in the circumferential direction is used as a pocket for holding the needle in a freely rollable manner, and the outer surface of at least one rim portion of the both rim portions. In the radial needle bearing retainer used in a state in which displacement is restricted in the axial direction by sliding contact with another member disposed adjacent to the outer surface, the at least one rim portion By forming the outer surface of the outer surface of the outer diameter side of the at least one rim portion into the shape of the other outer surface, The feature is that it can slide on the member. Cage for a radial needle bearing that.

An inner ring raceway and an outer ring raceway that are arranged concentrically with each other, a plurality of needles that are provided between the inner ring raceway and the outer ring raceway so as to be able to roll, and a holder that holds the needles. A radial needle bearing comprising: a radial needle bearing, wherein the cage is a radial needle bearing cage according to claim 1.