KR102546430B1 - Needle rollers with cages and planetary gear mechanism support structure provided therewith - Google Patents

Abstract

The cage 2 is an outer ring guide type cage in which the outer diameter guide surface 20 contacts the outer ring raceway surface. The needle-shaped roller 1 is a crowning roller having a cylindrical surface portion 10 having a constant diameter in a central region and inclined surface portions 11 on both sides of the cylindrical surface portion 10. The outer diameter guide surface 20 of the retainer 2 and the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the acicular roller 1 are disposed at different positions in the axial direction. The boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 comes into contact with the retainer 2.

Description

Needle rollers with cages and planetary gear mechanism support structure provided therewith

The present invention relates to a needle-like roller with a cage and a planetary gear mechanism support structure having the same.

A needle roller with a cage is composed of a plurality of needle rollers and a cage, and the cage has a pair of annular portions spaced apart in the axial direction and a plurality of pillar portions extending in the axial direction and connecting the annular portions to each other. Then, the needle rollers are held in pockets formed between adjacent pillars along the circumferential direction. In addition, the needle-shaped roller has a cylindrical surface portion with a constant diameter in the central region in order to avoid an edge rod (excessive pressure generated at the end of the contact area when the roller and the raceway surface are in contact) with the mating member, and the cylindrical surface portion There is a case of using a crowning roller having inclined surface portions formed on both sides.

Conventionally, as described in Patent Literature 1, the length from the end surface of the roller to the boundary between the cylindrical surface portion and the inclined surface portion is Dp, and the shortest distance in the axial direction from the wall surface of the pocket facing the end surface of the roller to the cage guide surface is When A, it was set so that Dp<A was satisfied.

In the patent document 1 described above, an object is to provide a cage-attached roller having a long lifespan in which the length of the inclined surface portion can be adjusted so that the boundary portion between the cylindrical surface portion and the inclined surface portion does not contact the guide surface.

In addition, conventionally, as described in Patent Literature 2, an oil supply groove in the circumferential direction connecting between the pockets on both sides of the pillar part is formed on the outer diameter surface of the pillar part, and the axial position of the oil supply groove is determined by the roller accommodated in the pocket. There is one that is set to a position corresponding to the crowning joint.

In the case described in Patent Literature 2, by forming an oil supply groove on the outer diameter surface of the column portion to face the crowning joint of the roller, oil can be intensively supplied to the crowning joint, and oil film breakage in the same portion can be prevented, thereby improving bearing performance. It helps to promote longevity.

Japanese Unexamined Patent Publication No. 2008-215475 Japanese Unexamined Patent Publication No. 2013-53698

In Patent Literature 1, Dp (the length from the end surface of the roller to the boundary between the cylindrical surface portion and the inclined surface portion) < A (the shortest distance in the axial direction from the wall surface of the pocket facing the end surface of the roller to the guide surface of the cage), The boundary between the cylindrical surface portion and the inclined surface portion overlaps with the roller stopper portion in the axial direction. For this reason, when there is an inclination of the mounted shaft or housing, the boundary between the cylindrical surface portion and the inclined surface portion of the roller where edge surface pressure is generated is more prone to wear and peeling due to poor lubrication.

In Patent Literature 2, the boundary between the cylindrical surface portion and the inclined surface portion of the roller is in contact with the pillar portion of the retainer. If they contact in this way, there is a fear that the lubricating oil will be scraped off the roller by this contact, resulting in poor lubrication.

In view of the above problems, the present invention provides a caged needle roller and a planetary gear mechanism supporting structure provided therewith, in which a portion with high edge surface pressure is less prone to lubrication failure and wear and peeling are suppressed.

The caged needle roller of the present invention is a caged needle roller comprising a plurality of needle rollers and a retainer, wherein the cage extends in the axial direction with a pair of annular portions spaced apart in the axial direction to connect the annular portions to each other. It is an outer ring guide type retainer having a plurality of pillar portions having an outer diameter guide surface contacting an outer ring raceway surface, wherein the needle roller is a crowning roller having a cylindrical surface portion having a constant diameter in a central region and inclined surface portions on both sides of the cylindrical surface portion, wherein the The outer diameter guide surface of the retainer and the boundary between the cylindrical surface and the inclined surface of the needle roller are provided at different positions in the axial direction, and the boundary between the cylindrical and inclined surface of the needle roller does not come into contact with the cage.

According to the cage-equipped needle roller of the present invention, the boundary between the cylindrical surface portion and the inclined surface portion of the needle roller is centered in the axial direction rather than the cage guide surface so that it does not overlap in the axial direction with the outer ring raceway surface (contact surface with the housing inner diameter) serving as the cage guide surface. It will be placed to the side. Therefore, it becomes difficult for a high edge surface pressure part to become lubrication failure. Further, the boundary between the cylindrical surface portion and the inclined surface portion of the needle-shaped roller is prevented from contacting the retainer. For this reason, even when the mounted shaft or housing is tilted, the boundary between the cylindrical surface portion and the inclined surface portion of the needle roller, where edge surface pressure is generated, is unlikely to become lubricated.

By the way, as a cage guide type, raceway guide is more preferable than roller guide from the viewpoint of cage movement stability under high-speed motion, and outer ring guide is more preferable than inner ring guide from the viewpoint of lubricating oil behavior by centrifugal force.

It is preferable that the cylindrical surface portion of the needle roller is in contact with the retainer. With this configuration, it is possible to effectively prevent the needle roller from falling off, and also to stabilize the rotation of the needle roller. Further, it is preferable that the outer diameter guide surfaces of the cage contacting the outer ring raceway surface are formed at both ends in the axial direction. Thereby, the function as a bearing can be exhibited stably.

The retainer has an outer diameter side roller stopper provided at both ends in the axial direction on an outer diameter side than a roller pitch circle diameter, and an inner diameter side roller stopper provided at an inner diameter side than a roller pitch circle diameter at a center portion in the axial direction. It is preferable to arrange a boundary between the cylindrical surface portion and the inclined surface portion at a position where they do not overlap in the axial direction by the outer diameter side roller stopper and the inner diameter side roller stopper of the cage.

With this configuration, since the retainer has the outer diameter side roller stopper and the inner diameter side roller stopper, dropping of the needle roller can be effectively prevented. In addition, since the boundary between the cylindrical surface portion and the inclined surface portion of the roller is arranged so as to be closer to the center in the axial direction than the roller stopper portion on the outer diameter side so as not to overlap in the axial direction with the roller stopper portion for preventing the roller from falling off to the outer diameter from the retainer, It is difficult for the surface pressure part to become poorly lubricated.

It is preferable that the retainer has an inclined connection portion connecting the outer diameter side roller stopper and the inner diameter side roller stopper, and the inclined connection portion has a concave shape to avoid interference with the needle roller.

It is preferable that pockets in which needle-like rollers are disposed are formed between pillars adjacent to each other in the circumferential direction of the retainer, and these pockets radially extend from the inner diameter side to the outer diameter side. The retainer can be said to be a welded joint product of steel sheets into which pockets have been punched.

By the way, roller bearings have an advantage of high load capacity because rollers as rolling elements and raceways are in linear contact. On the other hand, it is known that surface pressure concentration called edge load tends to occur at the end of the effective contact portion between the roller and the raceway, and when this becomes excessive, it causes a decrease in bearing life. In order to avoid the occurrence of edge load, when designing a roller bearing, it is common to form a crowning in which the generatrix shape is non-linear on at least one of the outer circumferential surface (rolling surface), outer ring raceway surface, or inner ring raceway surface of the roller. Further, as the crowning that suppresses the edge load and makes the contact surface pressure uniform, it is preferable that the generatrix shape of the crowning is represented by a logarithmic curve. For this reason, it is preferable that the needle-shaped roller has a logarithmic crowning shape approximated by a logarithmic function, for example.

The needle roller has a logarithmic crowning shape approximated by a logarithmic function, and the outline of the crowning in the axial cross section is the y-axis of any one of the inner ring raceway surface, the outer ring raceway surface, and the roller raceway surface, It is represented by Equation 1 using a y-z coordinate system in which the z-axis is taken in the direction orthogonal to the generatrix, and the axial length of the cylindrical surface portion is preferably 40 to 70% of the total length of the roller.

[Formula 1]

However, in Equation 1, A is represented by Equation 2 below, and a is the length from the origin taken on the generatrix of any one of the inner ring raceway surface, the outer ring raceway surface, and the roller raceway to the end of the effective contact portion.

[Equation 2]

In the needle-shaped roller set in this way, the contact surface pressure does not become excessive even when the bearing has a small inclination, and edge load is hardly generated even when the bearing has a large inclination.

The retainer may be M-shaped with an inward flange at the outer end of the annular portion or V-shaped without an inward-facing flange at the outer end of the annular portion.

The planetary gear mechanism support structure of the present invention includes an internal gear, a sun gear disposed at the center of the internal gear, a plurality of planet gears engaged with the internal gear and the sun gear, and a carrier supporting the planet gears. As a support structure for supporting a planetary gear mechanism, the planetary gear is rotatably supported by a pinion shaft installed in the carrier through a rolling bearing, and the rolling bearing is composed of the needle roller attached to the cage.

Since the planetary gear mechanism support structure of the present invention uses the cage-attached needle roller as a rolling bearing, it is possible to effectively prevent the needle roller from falling off. In addition, even if the length of the crowning is long, it will not become difficult to attach when attaching to the shaft or the inner diameter of the housing. In addition, it is possible to reduce the deterioration of the inflow possibility of the lubricating oil. In addition, it becomes difficult for a high edge surface pressure part to become lubrication failure.

The outer diameter surface of the pinion shaft is the inner raceway surface and the inner diameter surface of the planetary gear is the outer ring raceway surface, and the retainer used for the needle roller with the cage is composed of the inner diameter surface of the planetary gear at both ends in the axial direction. An oil passage hole may be formed in contact with the outer raceway surface and open to the inner raceway surface constituted by the outer diameter surface of the pinion shaft inside the pinion shaft.

In this way, the needle roller for cage can be lubricated by forming the oil passage hole. As a cage guide type, raceway guide is more preferable than roller guide from the viewpoint of cage movement safety under high-speed motion, and outer ring guide is more preferable than inner ring guide from the viewpoint of lubricating oil behavior by centrifugal force.

The planetary gear mechanism support structure can be used in transmissions for automobiles. In the case of using an automobile transmission as described above, the amount of lubricating oil is small because of the structure in which the oil enters the through hole of the pinion shaft (support shaft) by scattering. Therefore, it is optimal to use this planetary gear mechanism support structure for an automobile transmission.

According to the present invention, it is possible to suppress the occurrence of abrasion or peeling in a portion with high edge surface pressure, which is unlikely to result in poor lubrication. For this reason, it is possible to provide a suitable needle-like roller with a retainer having excellent durability.

1 is a sectional view of a needle roller with a cage according to a first embodiment of the present invention.
Fig. 2 is an enlarged cross-sectional view of a principal part of a cage of needle rollers with a cage shown in Fig. 1;
3 is an enlarged view of a pocket of the retainer.
4 is an enlarged cross-sectional view taken along line AA of FIG. 2 .
Fig. 5 is a side view of the needle roller of the needle roller with cage of the present invention.
Fig. 6 is a cross-sectional view of a needle roller with a cage according to a second embodiment.
Fig. 7 is an enlarged cross-sectional view of a principal part of a cage of needle rollers with a cage shown in Fig. 6;
Fig. 8 is an enlarged view of pockets of cages of the needle rollers with cages shown in Fig. 6;
9 is an enlarged cross-sectional view along line BB of FIG. 6 .
Fig. 10 is an enlarged cross-sectional view of principal parts of a cage of needle rollers with cages according to a second embodiment.
11 is a simplified diagram of a planetary gear mechanism.
Fig. 12 is a sectional view of the support structure of the planetary gear mechanism.
13 is a cross-sectional view of a main part of an automobile transmission.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on FIGS. 1-13. 1 shows a cage attached needle roller 30, which is configured by attaching a plurality of needle rollers 1 to a cage 2. In the following description, the direction along the central axis of the cage-equipped needle roller 30 is referred to as "axial direction", the direction orthogonal to the central axis is referred to as "radial direction", and the direction along an arc centered on the central axis is referred to as "axis direction". circumferential direction”.

The retainer 2 has a pair of annular portions 3 and 3 spaced apart in the axial direction, and a plurality of pillar portions 4 extending in the axial direction and connecting the annular portions 3 and 3 to each other. Then, a plurality of pockets 5 having a shape as shown in FIG. 3 are formed between the pillar portions 4 and 4 adjacent to each other along the circumferential direction, and needle rollers 1 are arranged in the pockets 5. Further, this retainer 2 has an inward flange 3a at the outer end of the annular portion 3. In Fig. 1, PCD represents the pitch circle diameter (pitch circle diameter) of the acicular roller 1.

In this case, a concave portion 19 is formed in the central portion of the outer circumferential surface of the pillar portion 4, and outer diameter guide surfaces 20 and 20 are provided at both ends of the acicular roller 1 in the axial direction to form a bulge on the outer diameter side. . As will be described later, the outer diameter guide surface 20 contacts the outer ring raceway surface constituted by the inner diameter surface of the planetary gear 17 (see Fig. 11). As shown in FIG. 1 , the outer diameter guide surface 20 has a range H extending from the annular portion 3 of the outer circumferential surface of the retainer 2 to a part of the starting pillar portion 4. During rotation, the cage 2 comes into guiding contact with the inner peripheral surface (inner diameter surface) of the pinion (planetary gear) 17 on this outer diameter guide surface 20 .

As shown in Fig. 5, the needle-shaped roller 1 has a crown having a cylindrical surface portion 10 having a constant diameter in a central region and inclined surface portions 11 formed on both sides of the cylindrical surface portion 10 (hereinafter also referred to as a crowning portion). It's a Ning Roller.

In general, roller bearings have an advantage of large load capacity because rollers as rolling elements and raceways are in line contact. On the other hand, concentration of surface pressure called edge load tends to occur at the end of the effective contact portion between the roller and the raceway, and if this becomes excessive, care must be taken in lowering the life of the bearing. In order to avoid the occurrence of edge load, when designing a roller bearing, it is common to form a crowning in which the generatrix shape is non-linear on at least one of the outer circumferential surface (rolling surface), outer ring raceway surface, or inner ring raceway surface of the roller. As the crowning that suppresses the edge load to make the contact surface pressure uniform, it is preferable to make the generatrix shape of the crowning represented by a logarithmic curve. For this reason, it is preferable that the needle roller 1 of the caged needle roller 30 according to the present invention has a logarithmic crowning shape approximated by a logarithmic function, for example.

Here, log crowning applied to the needle roller 1 will be described. The generatrix lines of the crowning portions 11b and 11b of the rolling surface 1a of the needle roller 1 are obtained based on the logarithmic curve of logarithmic crowning represented by the following equation (Equation 1). This logarithmic crowning formula is cited as described in Patent No. 4429842 of the present applicant. In this case, the outline of the crowning in the axial cross section of the roller bearing is set to the y-axis of either the inner ring raceway surface, the outer ring raceway surface, or the roller raceway surface, and the z-axis is taken in the orthogonal direction of the generatrix. Using a y-z coordinate system, It is represented by Equation 1.

[Formula 3]

In Equation 1, A is represented by Equation 2 below, and a is the length from the origin taken on the generatrix of any one of the inner ring raceway surface, the outer ring raceway surface, and the roller raceway to the end of the effective contact portion.

[Formula 4]

The design parameters K ₁ , K ₂ , and z _m in the logarithmic crowning equation are subject to design. The mathematical optimization method of log crowning is described. After determining the design parameter K ₂ , optimal logarithmic crowning can be designed by appropriately selecting K ₁ and z _m in the functional expression representing logarithmic crowning. Crowning is generally designed to reduce the maximum value of the surface pressure or stress of the contact area. Here, the rolling fatigue life is considered to be generated according to Mises' yield condition, and K ₁ , z _m is selected so as to minimize the maximum value of Mises' equivalent stress. K ₁ , z _m can be selected using an appropriate mathematical optimization method. Various algorithms for mathematical optimization methods have been proposed, but one of them, the direct search method, is capable of performing optimization without using differential coefficients of a function, and the objective function and variables cannot be directly expressed by expressions. useful in case Here, K ₁ , z _m is obtained using the Rosenbrock method, one of the direct search methods.

The shape of the crowning portions 11, 11 of the acicular roller 1 in the present embodiment is a logarithmic curve crowning obtained by the above formula. By setting in this way, the contact surface pressure can be suppressed to a low level even when the shaft on which the cage-equipped needle roller 30 is mounted has an inclination or the like, and a longer service life can be achieved. However, the logarithmic shape is not limited to the above formula, and a logarithmic curve may be obtained using another logarithmic crowning formula.

The crowning portion 11 of the needle roller 1 is crowned by machining or barrel processing. Here, barrel processing is a process of putting a needle roller and an abrasive into a barrel, and forming crowning portions at both ends of the needle roller. In the case of crowning the crowning portion 11 of the acicular roller 1 by barrel processing, the drop amount from the outer circumferential surface of the cylindrical surface portion 10 (the outermost end of the cylindrical surface portion 10 in the radial direction) is, for example, 0.5 μm. It is preferable to set the position as the border region 12 . Further, in the case of forming the crowning portion by barrel processing, a very small amount of the straight portion (cylindrical surface portion 10) of the needle-like roller 1 is also dropped during processing, making it difficult to define the straight portion. For this reason, it is preferable to define a crowning starting point (a boundary between the cylindrical surface portion 10 and the inclined surface portion 11) at a position 0.5 μm away from the outermost diameter of the needle-shaped roller 1.

As shown in FIG. 5 , the acicular roller 1 has an axial length L1 of the cylindrical surface portion 10 in the center region of 40 to 70% of the total length of the acicular roller 1 (length in the axial direction of the roller) L. is doing When the shape of the crowning of the acicular roller 1 is log-shaped, there is a feature that the drop amount is small at the start of the crowning and the drop amount increases remarkably as it approaches the end. Therefore, if the straight portion (cylindrical surface portion) 10 is too short, that is, if the crowning length is too long, the drop amount becomes large on the side closer to the end. For this reason, processing takes time and becomes expensive. Conversely, if the straight portion (cylindrical surface portion) 10 is too long, that is, if the crowning length is too short, the drop amount becomes small. For this reason, when the bearing is inclined, edge rods tend to occur. In addition, the drop amount here is the amount of reduction in the radial direction generated by crowning.

Therefore, by setting the axial length L1 of the cylindrical surface portion 10 in the center region to 40 to 70% of the total length (roller axial length) L of the acicular roller 1, the contact surface pressure is small even when the inclination of the bearing is small. This does not become excessive, and even when the inclination of the bearing is large, it becomes difficult to generate edge rods.

That is, as shown in Table 1 below, when the straight length of the straight portion (cylindrical surface portion) 10 is less than 40%, the contact surface pressure does not become excessive when the inclination of the bearing is small, but when the inclination of the bearing is large, Edge load is likely to occur. In addition, when the straight length of the straight part (cylindrical surface part) 10 exceeds 70%, the contact surface pressure does not become excessive when the bearing has a large inclination, but the contact surface pressure tends to become excessive when the bearing has a small inclination.

By the way, in the caged needle roller bearing 30, a welded cage is employed as the cage 2 in order to increase the load capacity (to make the roller length as long as possible and the number of rollers to be increased). The manufacturing process of the welding retainer is approximately as follows.

(a) As a raw material, a belt-shaped steel material obtained by shearing a cold-rolled steel sheet such as SPC with good formability to a predetermined width by a slitter or the like is used.

(b) A basic cross-sectional shape (M-shape or V-shape) of the cage is formed by performing press working on the strip-shaped steel material.

(c) Pockets are formed by punching at a predetermined pitch in the longitudinal direction of the belt-shaped steel material. After that, the belt-shaped steel material is cut into a predetermined length considering the welding table at both ends.

(d) The belt-shaped steel materials are annularly bent.

(e) Butt both ends and weld.

After that, heat treatment such as nitriding treatment or carburizing quenching is performed to remove deformation caused by welding and to form a hardened layer on the surface of the retainer.

For the welding retainer manufactured in this way, thin strip steel materials are used in order to be annularly bent. For this reason, it is possible to make the width dimension of the punched-out remaining part to be a columnar part formed between adjacent pockets relatively small, and also to make the length dimension of the pocket corresponding to the roller length relatively large. Therefore, by using the welding retainer, the length of the rollers can be increased and the number of rollers can be increased. Further, by making the retainer 2 a welded retainer, the pocket 5 radially spreads from the inner diameter side toward the outer diameter side, and the contact of the needle-shaped roller 1 to the connecting portion of the pocket 5 is effectively made possible. It can be prevented.

Further, in the cage in the embodiment, the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 are arranged so as not to overlap in the axial direction, and the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 ) is arranged so that the boundary portion 12 of ) does not overlap the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 in the axial direction. For this reason, when the bearing is inclined, it is possible to secure an oil film in the vicinity of the crowning starting point (the boundary 12 between the cylindrical surface portion 10 and the inclined surface portion 11) where the contact stress is maximized, and the crowning opening It is possible to suppress occurrence of abrasion, peeling, etc. of the viewing point, resulting in a longer life.

The starting point of the crowning of the needle roller 1 (the interface 12 between the cylindrical surface portion 10 and the inclined surface portion 11) is not allowed to contact the retainer 2. By doing this, it is possible to secure an oil film at the crowning start point, suppress wear and peeling at the crowning start point, and achieve a long life.

The crowning starting point of the needle roller 1 (the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) is not brought into contact with the retainer 2, so that the crowning portion (inclined surface portion 11) It is not necessary to make the roundness too small, and it is possible to prevent abrasion or the like of the starting point (the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11). Specifically, the roundness of the crowning portion (inclined surface portion 11) of the acicular roller 1 may be 0.6 to 2.0 μm.

In addition, by using a log shape for the crowning shape of the needle roller 1, the contact surface pressure can be suppressed to a low level even when there is an inclination of the shaft and the like, resulting in a longer service life.

By the way, in the pillar part 4, a rectangular notch part (concave part) 9 is formed at the position corresponding to the boundary part 12 of the cylindrical surface part 10 and the inclined surface part 11. That is, each pocket 5 has four notch portions (concave portions) 9 . For this reason, as shown in Figs. 1 to 3, in a state where the needle-shaped roller 1 is fitted to the pocket 5, the boundary 12 between the cylindrical surface portion 10 and the inclined surface portion 11 forms a retainer 2. It is in a non-contact state that does not come into contact with (pillar part 4 of).

In addition, the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 is arranged axially inside the outer diameter guide surface 20, so that the outer diameter guide surface 20 of the retainer 2 and the boundary portion 12 is placed at a different position in the axial direction.

That is, the cage guide surface is such that the interface 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 does not overlap in the axial direction with the outer ring raceway surface serving as the cage guide surface (contact surface with the housing inner diameter). It is arrange|positioned so that it may become more axial direction center side. For this reason, it becomes difficult for a high edge surface pressure part to become lubrication failure. In addition, the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 is prevented from contacting the retainer 2 by forming a notch portion 9 in the pocket 5. (The border region 12 and the retainer 2 become non-contact). Therefore, even when the mounted shaft or housing is tilted, the interface 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the acicular roller 1 where edge surface pressure is generated is unlikely to become lubricated.

In this way, in the caged acicular roller 30 shown in FIG. 1, the portion with high edge surface pressure is unlikely to result in poor lubrication, and wear and peeling can be suppressed. For this reason, it is possible to provide a high-quality needle-shaped roller with a retainer having excellent durability. In addition, since the cage guide type is an outer ring guide type, the safety of the cage motion under high-speed motion is excellent, and it is also a preferred configuration from the viewpoint of lubricating oil behavior by centrifugal force.

By the way, in the caged needle roller 30 shown in Fig. 1, it is preferable that the cylindrical surface portion 10 of the needle roller 1 comes into contact with the cage 2 (the inner diameter side roller stopper 7). Such contact can effectively prevent the needle roller 1 from falling off, and also stabilize the rotation of the needle roller 1. Further, the outer diameter guide surfaces 20 of the cage 2 that come into contact with the outer ring raceway surface are formed at both ends in the axial direction. For this reason, the needle roller 30 with cage shown in Fig. 1 can stably exhibit its function as a bearing.

Next, the cage 2 of the needle-shaped roller 30 with cage shown in FIG. 6 has a substantially M-shaped cross section, and since it has such a cross-sectional shape, the cage 2 shown in FIG. 6 is M-shaped. is called a retainer. The M-shaped retainer has an inward flange 3a at the outer end of the annular portion 3.

The pillar portion 4 includes a pair of outer diameter portions 4a and 4a, an inner diameter portion 4b, and an inclined portion 4c. The outer diameter portion 4a extends inwardly in the axial direction from each outer diameter portion of the pair of annular portions 3 . The inner diameter portion 4b is between the pair of annular portions 3 and 3 and is disposed closer to the inner diameter than the outer diameter portion 4a. The inclined portion 4c connects the outer diameter portion 4a and the inner diameter portion 4b.

7 and 9, an outer diameter side retainer (hereinafter also referred to as an outer diameter side roller stopper) 6 is formed in the outer diameter portion 4a, and an inner diameter side retainer (hereinafter, referred to as an inner diameter side roller stopper) 6 is formed in the inner diameter portion 4b. Also called a roller stopper) 7 is formed. The outer diameter side retainer 6 includes an inner diameter side taper portion 6a protruding into the pocket 5 from the inner diameter side toward the outer diameter side and an outer diameter side taper portion protruding into the pocket 5 from the outer diameter side toward the inner diameter side. (6b). The acicular roller 1 disposed in the pocket 5 is received by the inner diameter side taper portion 6a. In addition, the inner diameter side retainer 7 includes an outer diameter side taper portion 7a protruding into the inside of the pocket 5 from the outer diameter side toward the inner diameter side, and an outer diameter side taper portion 7a extending radially inward from the inner diameter end of the outer diameter side taper portion 7a. It has an end face part 7b. The acicular roller 1 disposed in the pocket 5 is received by the inner diameter side taper portion 6a and the outer diameter side taper portion 7a. Further, as long as the amount of movement of the roller 1 relative to the retainer 5 can be secured, the inner diameter side taper portion 6a and the outer diameter side taper portion 7a may not be provided.

By the way, as shown in Fig. 6, in the retainer 2, the outer diameter side retainer 6 is disposed on the outer diameter side of the roller pitch circle diameter PCD, and the inner diameter side retainer 7 has the pitch circle diameter PCD. ) is arranged on the inner diameter side. By this, the outer diameter side retainer 6 and the inner diameter side retainer 7 are set so as not to overlap in the axial direction. That is, the outer diameter side retainer 6 is offset axially outward with respect to the inner diameter side retainer 7 .

6 and 10, in a state where the needle roller 1 is disposed in the pocket 5 of the retainer 2, the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 The boundary portion 12 of corresponds to the inclined portion 4c connecting the outer diameter portion 4a and the inner diameter portion 4b. For this reason, the boundary portion 12 of the acicular roller 1 is in a state where it does not overlap the outer diameter side retainer 6 and the inner diameter side retainer 7 in the axial direction. That is, the boundary portion 12 is offset with respect to the outer diameter side retainer 6 and the inner diameter side retainer 7 .

In this case, the inclined portion 4c connecting the outer diameter portion 4a and the inner diameter portion 4b constitutes a connection portion 8 connecting the outer diameter side retainer 6 and the inner diameter side retainer 7, and this connection portion ( 8) has a concave shape shown in FIG. 8 . That is, the notch portion 9 in the shape of a trapezoid triangle is formed in the inclined portion 4c. The boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller is between the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 of the retainer 2, that is, at the connection portion 8 It is set so as to be disposed at the corresponding position, and it is set so that the border region 12 does not come into contact with the connecting portion 8.

By the way, although the retainer 2 of the needle roller 30 with cage shown in FIG. 6 is called an M-type cage as described above, it may be called a V-type cage as shown in FIG. 10 . . The M-shaped retainer shown in FIG. 7 has an inward flange 3a at the outer end of the annular portion 3, whereas the one called a V-shaped cage as shown in FIG. 10 does not have such a flange. For this reason, in this embodiment, the M type cage shown in FIG. 6 may be used or the V type cage shown in FIG. 10 may be used.

In the caged needle roller 30 shown in Figs. 6 and 10, the retainer 2 has an outer diameter side roller stopper 6 and an inner diameter side roller stopper 7, so that the needle roller 1 is effectively removed. It can be prevented. In addition, the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the roller 1 is axially with the roller stopper portion for preventing the roller 1 from falling off from the retainer 2 to the outer diameter. Since it is arranged so as to be closer to the center side in the axial direction than the roller stopper portion 6 on the outer diameter side so as not to overlap, it is difficult for the portion with high edge surface pressure to become poorly lubricated. In addition, since the boundary between the cylindrical surface and the inclined surface of the roller is arranged so that it does not overlap with the outer diameter side roller stopper and the inner diameter side roller stopper in the axial direction, when the bearing is inclined, it is near the crowning start point where the contact stress is maximum (tubular surface part It is possible to secure an oil film in the vicinity of the boundary between the and the inclined surface portion), and suppress the occurrence of abrasion or peeling at the crowning start point, so that a longer life can be achieved. In addition, even if the length of the crowning is long, it will not become difficult to mount when attaching to the shaft or the inner diameter of the housing.

In addition, the inner diameter side roller stopper part 7 is not disposed on the inner diameter side of the outer diameter side roller stopper part 6 to form a space between the retainer 2 and the needle roller 1, so that the roller stopper part 6, 7) is positioned in the axial direction on both sides (inner diameter side and outer diameter side), so that deterioration in the inflow of lubricating oil can be reduced. In particular, in the planetary gear mechanism support structure, when the cage 2 is of the outer ring guide type, the outer guide surface of the cage 2 and the inner circumferential surface of the pinion shaft 18a (see Figs. 11 and 12) as will be described later. Since the area of the contact guide portion is large, oil passage through the end of the acicular roller 1 and between the outer diameter guide surface of the retainer 2 and the inner circumferential surface of the pinion shaft 18 are important. Therefore, it is effective to use the needle roller 30 with cage. Further, in the above embodiment, the outer diameter guide surface and the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the acicular roller 1 are arranged so as not to overlap each other in the axial direction. Even with this setting, when the bearing is inclined, it is possible to secure an oil film near the crowning starting point (near the boundary between the cylindrical surface portion and the inclined surface portion) where the contact stress is maximized, and to prevent wear and tear at the crowning starting point. Occurrence of peeling or the like can be suppressed, and lifetime improvement can be achieved.

In addition, the boundary portion 12 of the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 is arranged so as to be at both ends in the axial direction than the inner roller stopper portion 7, so that the high edge surface pressure portion is poor in lubrication. it becomes difficult to become The axial position of the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 is the outer diameter side roller stopper portion 6 and the inner diameter side roller stopper portion 7 of the retainer 2 ), but this connection portion 8 has a structure that does not come into contact with the retainer 2. In this way, it is possible to secure an oil film at the crowning starting point, suppress abrasion or peeling at the crowning starting point, and achieve a longer life. In addition, there is no need to excessively reduce the roundness of the crowning portion (inclined surface portion), and wear and the like at the starting point of crowning can be prevented. The crowning starting point of the needle roller 1 (the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) is not brought into contact with the retainer 2, so that the crowning portion (inclined surface portion 11) It is not necessary to make the roundness too small, and it is possible to prevent abrasion or the like of the starting point (the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11). Specifically, the roundness of the crowning portion (inclined surface portion 11) of the needle-shaped roller 1 may be 0.6 to 2.0 μm.

In addition, by using a log shape for the crowning shape of the needle-like roller 1, the contact surface pressure can be suppressed to a low level even when there is an inclination of the shaft and the like, resulting in a longer service life.

For this reason, in the caged needle roller 30 shown in FIGS. 6 and 10, the portion with high edge surface pressure is unlikely to become defective in lubrication, so that wear and peeling can be suppressed, and deterioration in the inflow of lubricating oil is effectively prevented. can do. For this reason, it is possible to provide a high-quality needle roller 30 with cage suitable for durability. In addition, even when the crowning length of the roller 1 is increased, it is excellent in attachability when attached to a shaft or an inner diameter of a housing.

In addition, since the concave portion 9 is formed in the retainer 2, the outer diameter guide surface 20 and the outer ring raceway surface (for example, a planetary gear 17 described later (see FIG. 11)) are formed through the concave portion 9. The lubricating oil is guided between the inner circumferential surfaces of the This makes it possible to form an oil film between the outer circumferential surface (outer diameter guide surface 20) of the cage 2 and the inner circumferential surface of the planetary gear 17 to reduce friction, and also to reduce the life of the needle roller 30 with the cage. contribute to improvement

As the retainer 2, even when an M-type retainer 2 having an inward flange 3a at the outer end of the annular portion 3 or a V-type one having no inward flange at the outer end of the annular portion is used, the needle roller 1 as shown in FIG. A roller having a logarithmic crowning shape approximated by a logarithmic function as shown in Fig. 5 is used. For this reason, even when there is an inclination or the like on the shaft on which the needle roller 30 with the cage is attached, the contact surface pressure can be suppressed to a low level, and the life span can be improved.

In the retainer 2 shown in Figs. 2, 7 and 10, a steel plate obtained by punching holes to be pockets 5 is rounded, and the junctions thereof are integrally formed by welding. That is, the retainer 2 is made of a welded joint of steel plates into which the pockets 5 are punched. If formed in this way, the pocket 5 widens radially from the inner diameter side toward the outer diameter side, and it is possible to effectively prevent the roller 1 from coming into contact with the connecting portion of the pocket 5 of the retainer 2. there is.

By the way, the caged needle roller 30 of the present embodiment can be used for a supporting structure for supporting the planetary gear mechanism S as shown in FIG. 11 . The planetary gear mechanism S includes an internal gear (ring gear) 15, a sun gear (sun gear) 16 disposed at the center of the internal gear 15, an internal gear 15 and a sun gear 16 ) is provided with a plurality of planetary gears (pinions) 17 meshed with.

That is, the sun gear 16 is located at the center of the large internal gear 15, and a plurality of planetary gears 17 are interposed between the internal gear 15 and the sun gear 16. As shown in FIG. 8 , each planetary gear 17 is rotatably supported by the pinion shaft 18a of the carrier 18 .

In this case, a needle roller 30 with a cage is disposed between the pinion shaft 18a and the planetary gear 17, and the needle roller 30 with a cage drives the planetary gear 17 on the pinion shaft 18a. By rotatably supporting it, it is possible to constitute a support structure for supporting the planetary gear mechanism S.

In the cage 2 of the needle roller 30 with cage, the outer diameter surface of the pinion shaft 18a is the inner raceway surface and the inner diameter surface of the planetary gear 17 is the outer ring raceway surface. The retainer 2 constitutes an outer diameter guide surface 20 (see Fig. 1) that contacts the outer ring raceway surface constituted by the inner diameter surface of the planetary gear 17 at both ends in the axial direction thereof. Here, the outer diameter guide surface 20 is a range H extending from the annular portion 3 of the outer circumferential surface of the retainer 2 to a part of the base pillar portion, as shown in FIG. 1 and the like. During rotation, the cage 2 comes into guiding contact with the inner peripheral surface (inner diameter surface) of the pinion (planetary gear) 17 on this outer diameter guide surface 20 . For this reason, the retainer 2 is of the outer ring guide type.

By the way, as a cage guide type, raceway guide is more preferable than roller guide from the viewpoint of cage movement safety under high-speed motion, and outer ring guide is more preferable than inner ring guide from the viewpoint of lubricating oil behavior by centrifugal force.

Further, an oil passage hole 18b for supplying lubricating oil is formed inside the pinion shaft 18a. The oil passage hole 18b includes a first oil passage hole 18ba extending in the axial direction of the pinion shaft 18a and a first oil passage hole 18ba extending in the radial direction of the pinion shaft 18a from the first oil passage hole 18a. It has 2 oil passage holes 18bb. The 2nd oil passage hole 18bb communicates the 1st oil passage hole 18ba and the outer peripheral surface of the pinion shaft 18. Further, the second oil passage hole 18bb is formed at a position overlapping the cage attached needle roller 30 in the axial direction. The structure is such that the needle roller 30 with a cage is lubricated by introducing lubricating oil through an oil passing hole 18b formed inside the pinion shaft 18a and guiding it to the outer circumferential surface of the pinion shaft 18a. there is.

Further, as shown in Fig. 13, the needle roller 30 with a cage of this embodiment may be used as a support bearing for the transmission T. That is, the needle roller 30 with cage is a needle roller with cage for automobiles. This transmission (T) is provided with two planetary gear mechanisms (S, S) so that rotation is sequentially transmitted. In each of the planetary gear mechanisms S and S, a planetary gear 26 is attached to the support shaft 25 via a cage-attached needle roller 30. In this case, the outer diameter surface of the support shaft 25 is taken as the inner raceway surface, and the inner diameter surface of the planetary gear 26 is taken as the outer raceway surface. The retainer 2 constitutes an outer diameter guide surface 20 (see Fig. 1) that contacts an outer raceway surface constituted by an inner diameter surface of the planetary gear 26 at both ends thereof in the axial direction.

When the planetary gear mechanism is used in an automobile transmission, the amount of lubricating oil is small because of the structure in which the oil enters the through hole 27 of the support shaft (pinion shaft) 25 by scattering. In addition, needle rollers with cages used in transmissions are subjected to harsh environments such as centrifugal force or edge stress caused by unbalanced loads. Therefore, it is optimal to use the caged needle roller 30 of the present embodiment in an automobile transmission.

As mentioned above, although this embodiment was demonstrated, it is not limited to the said embodiment, and various modifications are possible, and the shape of the notch part 9 is a rectangular shape as shown in FIG. 3 or a triangular shape as shown in FIG. 8 It is not limited, and it is only necessary that the interface 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 does not contact the retainer 2. In addition, the shapes of the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 are not limited to those shown in FIG. It is good if there is a range that becomes a dimension between them in part. Further, as the outer diameter-side roller stopper 6, it may be provided on the entire outer diameter portion 4a of the pillar portion 4 or may be provided on a part of the outer diameter portion 4a of the pillar portion 4. Also, as the inner diameter side roller stopper 7, it may be installed on the entire inner diameter portion 4b of the pillar portion 4 or may be provided on a part of the inner diameter portion of the pillar portion 5.

(industrial applicability)

As the cage-equipped needle-shaped roller, a crowning roller having a cylindrical surface portion having a constant diameter in a central region and inclined surface portions provided on both sides of the cylindrical surface portion is used, and may be either single row or double row.

1: needle roller 2: retainer
3: annular part 3a: flange
4: pillar part 5: pocket
6: outer diameter side retainer part 7: inner diameter side retainer part
8: connection part 10: cylindrical surface part
11: slope portion 12: boundary portion
15: internal gear 16: sun gear
17: planetary gear 18: carrier
18a: pinion shaft 20: outer diameter guide surface
S: planetary gear mechanism T: transmission

Claims (12)

A needle roller with a cage comprising a plurality of needle rollers and a cage,
The retainer is an outer ring guide type retainer having a pair of annular portions spaced apart in the axial direction and a plurality of pillar portions extending in the axial direction and connecting the annular portions to each other, the outer diameter guide surfaces of which are in contact with the outer ring raceway surface,
In the retainer, a pocket in which the needle roller is disposed is formed between the pillar portions adjacent in the circumferential direction thereof, and
The needle roller is a crowning roller having a cylindrical surface portion having a constant diameter in a central region and a pair of inclined surface portions on both sides of the cylindrical surface portion;
The outer diameter guide surface of the cage and the boundary between the cylindrical surface portion and the inclined surface portion are disposed at different positions in the axial direction,
A notch portion for avoiding contact between the boundary portion and the pillar portion is installed only at a portion corresponding to the boundary portion of the cylindrical surface portion and the inclined portion portion of the pocket, and thus, even when an inclination occurs, the boundary, which is a portion where edge surface pressure occurs A needle roller with a cage characterized in that a portion does not contact the pillar portion. According to claim 1,
The needle roller with a cage, characterized in that the outer diameter guide surfaces of the cage contacting the outer ring raceway are formed at both ends in the axial direction. According to claim 1 or 2,
The retainer has an outer diameter side roller stopper provided at both ends in the axial direction on an outer diameter side than a roller pitch circle diameter, and an inner diameter side roller stopper provided at an inner diameter side than a roller pitch circle diameter at a central portion in the axial direction thereof,
A needle roller with a cage, characterized in that a boundary between the cylindrical surface portion and the inclined surface portion of the needle roller is disposed at a position that does not overlap in an axial direction by an outer diameter side roller stopper and an inner diameter side roller stopper of the cage. According to claim 3,
The retainer further has an inclined connection portion connecting the outer diameter side roller stopper and the inner diameter side roller stopper,
The needle roller with a cage, characterized in that the inclined connecting portion has a concave shape to avoid interference with the needle roller. According to claim 1 or 2,
Pockets in which the needle-like rollers are disposed are formed between the pillars adjacent to each other in the circumferential direction of the retainer,
The needle roller with a cage, characterized in that the pockets radially widen from the inner diameter side to the outer diameter side. According to claim 1 or 2,
The cage is a needle roller with a cage, characterized in that the cage is a welded joint product of steel sheets in which pockets are punched. According to claim 1 or 2,
The needle roller with a cage, characterized in that the needle roller has a logarithmic crowning shape approximated by a logarithmic function. According to claim 7,
The needle roller has a logarithmic crowning shape approximated by a logarithmic function, and the outline of the crowning in the axial cross section is the y-axis of any one of the inner ring raceway surface, the outer ring raceway surface, and the roller raceway surface, A needle roller with a cage, characterized in that it is represented by Equation 1 using a yz coordinate system in which the z-axis is taken in the direction orthogonal to the generatrix, and the length of the cylindrical surface in the axial direction is 40 to 70% of the total length of the roller.
[Equation 1]

[However, in Equation 1, A is represented by the following Equation 2, and a is the length from the origin taken on the generatrix of any one of the inner ring raceway surface, the outer ring raceway surface, and the roller raceway to the end of the effective contact portion]
[Equation 2]

According to claim 1 or 2,
The retainer is a needle roller with a cage, characterized in that the retainer is M-shaped having an inward flange at the outer end of the annular portion or V-shaped having no inward flange at the outer end of the annular portion. A planetary gear supporting a planetary gear mechanism comprising an internal gear, a sun gear disposed at the center of the internal gear, a plurality of planetary gears engaged with the internal gear and the sun gear, and a carrier supporting the planetary gear. As an instrument support structure,
The planetary gear mechanism characterized in that the planetary gear is rotatably supported by a pinion shaft installed in the carrier through a rolling bearing, and the rolling bearing is constituted by the caged needle roller according to claim 1 or 2. support structure. According to claim 10,
The outer diameter surface of the pinion shaft is the inner raceway surface and the inner diameter surface of the planetary gear is the outer ring raceway surface, and the retainer used for the needle roller with the cage is composed of the inner diameter surface of the planetary gear at both ends in the axial direction. A planetary gear mechanism support structure characterized in that an oil passage hole is formed in contact with the outer raceway surface and opens to an inner raceway surface constituted by an outer diameter surface of the pinion shaft inside the pinion shaft. According to claim 10,
A planetary gear mechanism support structure, characterized in that it is used in an automobile transmission.

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