WO2018164014A1

WO2018164014A1 - Needle roller with retainer and planetary gear mechanism support structure provided with same

Info

Publication number: WO2018164014A1
Application number: PCT/JP2018/008151
Authority: WO
Inventors: 理之冨加見; 将土屋
Original assignee: Ntn株式会社
Priority date: 2017-03-06
Filing date: 2018-03-02
Publication date: 2018-09-13
Also published as: CN110382891B; KR20190119052A; KR102508641B1; CN110382891A

Abstract

In the present invention, a retainer has outer-diameter-side roller stoppers provided farther diametrically outward than a roller pitch circle to both axial ends, and an inner-diameter-side roller stopper provided farther diametrically inward than the roller pitch circle to the axial center. The outer-diameter-side roller stoppers and the inner-diameter-side roller stopper are placed so as to not overlap in the axial direction. In the present invention, a needle roller is a crowning roller, which has in the center area a cylindrical surface part of fixed diameter, and which has inclined surface parts on both sides of the cylindrical surface part. The border regions between the cylindrical surface part and the inclined surface parts of the needle roller are disposed between the outer-diameter-side roller stoppers and the inner-diameter-side roller stopper of the retainer. The border regions between the cylindrical surface part and the inclined surface parts of the needle roller do not come into contact with the retainer.

Description

Needle roller with cage and planetary gear mechanism support structure having the same

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

The needle roller with a cage includes a plurality of needle rollers and a cage, and the cage includes a pair of annular portions spaced in the axial direction and a plurality of axial portions that extend in the axial direction and connect the annular portions to each other. It has a pillar part. And a needle roller is hold | maintained at the pocket formed between pillar parts adjacent along the circumferential direction. Also, the needle roller has a cylindrical surface part with a constant diameter in the center area in order to avoid edge loading with the mating member (excessive pressure generated at the end of the contact area when the roller and the raceway contact) And there are cases where a crowning roller having inclined surface portions provided on both sides of the cylindrical surface portion is used.

Conventionally, as described in Patent Document 1, the length from the roller end surface to the boundary portion between the cylindrical surface portion and the inclined surface portion is Dp, and the axial direction from the wall surface of the pocket facing the roller end surface to the cage guide surface Was set so as to satisfy Dp <A.

By setting in this way, 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, and an attempt is made to provide a roller with a long life. Is.

Further, conventionally, as described in Patent Document 2, in the cage, an inner protrusion and an outer protrusion that prevent the rollers from falling off are provided on the inner diameter side and the outer diameter side on both sides in the axial direction of the column portion. There is something. Also in this case, a crowning roller including a central straight portion (cylindrical surface portion) and crowning portions (inclined surface portions) on both sides thereof is used as the roller. And the inner side protrusion part and the outer side protrusion part of the pillar part are provided in the crowning part side rather than the joint (boundary part) of a straight part (cylindrical surface part) and the crowning part (inclined surface part) of the both sides.

With this configuration, the gap between the roller outer peripheral surface and the inner and outer projections of the column portion is widened. Therefore, the inner protrusion and the outer protrusion do not scrape the lubricant on the outer surface of the roller, and dust such as metal wear powder mixed in the lubricant does not stay in the inner protrusion and the outer protrusion. Therefore, the lubricating oil flows smoothly through the gap between the roller and the pocket.

Furthermore, conventionally, as described in Patent Document 3, in the cage, in the radial direction inside and outside, at three positions of the middle in the axial direction and the both ends in the axial direction in each of the pillar portions between the pockets adjacent in the circumferential direction. Some have extended oil grooves. Also in this case, a crowning roller comprising a cylindrical region (cylindrical surface portion) and crowning regions (inclined surface portions) on both sides thereof is used as the roller. The axially central edge of the oil groove provided at both axial ends coincides with or is connected to the connecting portion between the cylindrical region and the crowning region on the outer peripheral surface of the roller in a state of being accommodated in the pocket. It is arranged closer to the center in the axial direction than the roller.

¡By setting in this way, it is possible to prevent oil film breakage at the roller guide surface and to stabilize the rolling operation of the roller.

JP 2008-215475 A JP 2013-87886 A JP 2001-41250 A

ころ For rollers with cages (needle rollers with cages), it is desirable that the rollers have a structure that does not drop off from the cage so that they can be easily assembled to the shaft or housing. In the thing of the said patent document 1, the roller stopper part which hold | maintains a roller is comprised by the 1st linear part located in the radial direction outer side in a pillar part. In this case, it is necessary to make it smaller than the roller diameter so that the roller does not fall off. However, with this setting, the clearance between the roller stopper portion and the roller becomes small, so that it is difficult for the lubricating oil to enter, and wear and peeling due to poor lubrication are likely to occur.

Moreover, in this patent document 1, Dp (length from the roller end surface to the boundary portion between the cylindrical surface portion and the inclined surface portion) <A (axial direction from the wall surface of the pocket facing the roller end surface to the cage guide surface. Therefore, the boundary portion between the cylindrical surface portion and the inclined surface portion of the roller overlaps with the roller stopper portion and the axial position. For this reason, when the mounted shaft or housing is inclined, the boundary between the roller cylindrical surface portion and the inclined surface portion where the edge surface pressure is generated is more likely to be worn or peeled off due to poor lubrication.

In the thing of patent document 2, since both the inner side protrusion part and outer side protrusion part which are roller stoppers are in the axial direction both sides of a pillar part, and it exists in the substantially the same position in an axial direction, there exists a concern that the inflow property of lubricating oil may worsen There is.

In the case of the one described in Patent Document 3, if the contact surface pressure between the roller and the raceway is to be reduced in a case where the inclination of the shaft is large, the crowning length may be increased. However, if the crowning length is increased, the roller stopper moves to the axial center side. For this reason, a roller will be hold | maintained at the axial direction center side, and the inclination amount of a roller will become large with respect to a holder | retainer. When the inclination of the roller increases, when the needle roller with a cage is assembled to the shaft or the housing, there is a problem that the roller easily interferes with the shaft or the housing inner diameter and is difficult to assemble. Also in Patent Document 3, as in Patent Document 2, both the inner protrusion and the outer protrusion, which are roller stoppers, are on both sides in the axial direction of the column part, and are substantially at the same position in the axial direction. There is a concern that the influx of water will worsen.

Therefore, in view of the above-mentioned problems, the present invention prevents the roller from falling off without the occurrence of poor lubrication at the high edge surface pressure portion, suppressing the occurrence of wear and peeling, and without impairing the inflow of lubricating oil. The present invention provides a needle roller with a retainer and a planetary gear mechanism support structure including the same.

The needle roller with cage of the present invention is a needle roller with cage comprising a plurality of needle rollers and a cage, wherein the cage has a pair of annular portions spaced in the axial direction and an axial direction. A plurality of column portions that connect the annular portions to each other, and the retainer includes an outer diameter side roller stopper provided at an outer diameter side of the roller pitch circle diameter at both axial ends, and a shaft An inner diameter side roller stopper provided at an inner diameter side of the roller pitch circle diameter at a central portion in the direction, and the outer diameter side roller stopper and the inner diameter side roller stopper are disposed so as not to overlap in the axial direction. The tapered 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, and a boundary portion between the cylindrical surface portion and the inclined surface portion of the needle roller is disposed outside the cage. It is arranged between the diameter side roller stopper and the inner diameter side roller stopper, and the needle roller cylinder Boundary portion between the parts and the inclined surface portion in which is said retainer and non-contact.

According to the needle roller with a cage of the present invention, the cage has an outer diameter side roller stopper and an inner diameter side roller stopper, so that the needle roller can be effectively prevented from falling off. In addition, the boundary portion between the cylindrical surface portion and the inclined surface portion of the roller is more than the roller stop portion on the outer diameter side so that it does not overlap in the axial direction with the roller stop portion for preventing the roller from dropping off from the cage to the outer diameter. Since it is arranged so as to be on the axial center side, the high edge surface pressure portion is unlikely to be poorly lubricated. Moreover, even if the crowning length is long, it is not difficult to assemble when assembling to the mounted shaft or housing inner diameter.

Also, do not place the inner diameter side roller stopper on the inner diameter side of the outer diameter side roller stopper, and provide a space for the cage, so that both the roller stoppers (inner diameter side outer diameter side) axial direction It can reduce that the inflow property of lubricating oil becomes bad by being a position. Furthermore, the boundary portion between the cylindrical portion and the inclined portion of the roller is disposed so as to be on both ends in the axial direction with respect to the inner diameter side roller stopper, so that the high edge surface pressure portion is unlikely to be poorly lubricated. The axial position of the boundary part between the cylindrical part and the inclined part of the roller is the connection part (inclined part) between the outer diameter side roller stopper and the inner diameter side roller stopper of the cage. This part is in contact with the cage. It has a configuration that does not. This makes it difficult for the high edge surface pressure portion to be poorly lubricated.

It is preferable that the cage has an inclined connecting portion for connecting the outer diameter side roller stopper and the inner diameter side roller stopper, and the inclined connecting portion has a thin shape that avoids interference with the needle rollers.

It is preferable that a pocket in which needle rollers are arranged is formed between the column portions adjacent to each other in the circumferential direction of the cage, and the pocket is radially expanded from the inner diameter side to the outer diameter side. The cage may be a welded joint of steel plates with punched pockets.

Incidentally, the roller bearing has an advantage that the load capacity is high because the roller as the rolling element and the raceway surface are in line contact. On the other hand, it is known that contact pressure concentration called edge load is likely to occur at the end of the effective contact portion between the roller and the raceway surface, and if this is excessive, the bearing life is reduced. In order to avoid the occurrence of edge load, when designing roller bearings, a crowning with a non-linear busbar shape is formed on at least one of the outer circumferential surface (rolling surface), outer ring raceway surface, or inner ring raceway surface of the roller. It is common to do. In addition, as a crowning that suppresses the edge load and makes the contact surface pressure uniform, it is preferable that the shape of the busbar of the crowning is represented by a logarithmic curve. For this reason, it is preferable that the said needle roller is the logarithmic crowning shape of the shape approximated by a logarithmic function, for example.

The needle roller is a needle roller of a crowning roller having a logarithmic crowning shape approximated by a logarithmic function. One of the generatrixes of the surface is the y-axis, and the z-axis is taken in the direction perpendicular to the generatrix, and is expressed by Equation 1, and the axial length of the cylindrical surface portion is 40% of the total roller length. It is preferable to set it to 70%.

However, in Equation 1, A is expressed by the following Equation 2, and a is the length from the origin taken on any of the inner ring raceway surface, outer ring raceway surface or roller rolling surface to the end of the effective contact portion. That's it.

The needle roller configured in this way does not have an excessive contact surface pressure even when the bearing tilt is small, and edge load hardly occurs even when the bearing tilt is large.

The cage may be M-type having an inward flange at the outer end of the annular part or V-type not having an inward flange at the outer end of the annular part.

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 planetary gears meshed with the internal gear and the sun gear, and the planetary gear. A support structure for supporting a planetary gear mechanism including a carrier for supporting a gear, wherein the planetary gear is rotatably supported on a pinion shaft provided on the carrier via a rolling bearing, and the rolling bearing is provided. Is constituted by the needle roller with a cage.

Since the planetary gear mechanism support structure of the present invention uses the needle roller with a cage for the rolling bearing, the needle roller can be effectively prevented from falling off. Moreover, even if the crowning length is long, it is not difficult to assemble when assembling to the shaft or the housing inner diameter. Moreover, it can reduce that the inflow property of lubricating oil worsens. Furthermore, the high edge surface pressure portion is less likely to be poorly lubricated.

The outer diameter surface of the pinion shaft is the inner raceway surface, the inner diameter surface of the planetary gear is the outer ring raceway surface, and the cage used for the needle roller with cage is an inner diameter of the planetary gear at both ends in the axial direction. An oil passage hole that is in contact with the outer ring raceway surface constituted by a surface and that opens in the inner raceway surface constituted by the outer diameter surface of the pinion shaft can be provided inside the pinion shaft.

Thus, by providing the oil passage hole, the needle roller for the cage can be lubricated. As the cage guide type, the raceway guide is preferable to the roller guide from the viewpoint of the safety of the cage motion under high speed motion, and the outer ring guide is more preferable than the inner ring guide from the viewpoint of lubricating oil behavior due to centrifugal force. preferable.

The planetary gear mechanism support structure can be used for automobile transmissions. When the automobile transmission is used in this way, the amount of lubricating oil is small because of the structure that enters the oil passage hole of the pinion shaft (support shaft) by splashing. Therefore, it is optimal to use this planetary gear mechanism support structure for an automobile transmission.

In the present invention, the high edge surface pressure portion is unlikely to be poorly lubricated, the occurrence of wear and peeling can be suppressed, and the deterioration of the inflow property of the lubricating oil can be effectively prevented. For this reason, the suitable needle roller with a retainer excellent in durability can be provided. In addition, it is possible to effectively prevent the rollers from falling off. Moreover, even when the crowning length of the roller is increased, the assemblability is excellent when assembling to the shaft or the housing inner diameter.

It is sectional drawing of the needle roller with a holder | retainer of this invention. It is a principal part expanded sectional view of the retainer of the needle roller with a retainer shown in FIG. It is an enlarged view of the pocket of a holder | retainer. FIG. 3 is an enlarged sectional view taken along line AA in FIG. 2. It is a side view of the needle roller of the needle roller with a cage of the present invention. It is a principal part expanded sectional view of other embodiment of a holder | retainer. It is a simplified diagram of a planetary gear mechanism. It is sectional drawing of the support structure of a planetary gear mechanism. It is principal part sectional drawing of the transmission for motor vehicles.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 shows a needle roller 30 with a cage. The needle roller 30 with a cage is configured by assembling a plurality of needle rollers 1 to a cage 2. In the following description, the direction along the central axis of the needle roller 30 with cage is “axial direction”, the direction orthogonal to the central axis is “radial direction”, and the direction along the arc centered on the central axis is This is called “circumferential direction”.

The cage 2 includes a pair of

annular portions

3 and 3 that are spaced apart in the axial direction, and a plurality of column portions 4 that extend in the axial direction and connect the

annular portions

3 and 3 to each other. A plurality of pockets 5 having a shape as shown in FIG. 3 is formed between the

column parts

4 and 4 adjacent to each other along the circumferential direction, and the needle rollers 1 are disposed in the pockets 5. As shown in FIG. 2, the cage 2 has a substantially M-shaped cross section. Since the cage 2 has such a cross sectional shape, the cage 2 of this embodiment is called an M-type cage. The M-type cage has an inward flange 3 a 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 4 a extends inward in the axial direction from each outer diameter portion of the pair of annular portions 3. The inner diameter portion 4b is disposed between the pair of

annular portions

3 and 3 and on the inner diameter side with respect to the outer diameter portion 4a. The inclined portion 4c connects the outer diameter portion 4a and the inner diameter portion 4b.

As shown in FIGS. 2 and 4, an outer diameter side retainer (hereinafter also referred to as an outer diameter side roller stopper) 6 is formed on the outer diameter portion 4a, and an inner diameter side retainer (hereinafter referred to as an inner diameter side roller) is formed on the inner diameter portion 4b. 7 is also formed. The outer diameter side stopper 6 includes an inner diameter side taper portion 6a that protrudes from the inner diameter side toward the outer diameter side into the pocket 5, and an outer diameter side taper portion that protrudes from the outer diameter side toward the inner diameter side into the pocket 5. 6b. The needle roller 1 disposed in the pocket 5 is received by the inner diameter side taper portion 6a. Further, the inner diameter side stopper 7 includes an outer diameter side taper portion 7a protruding into the pocket 5 from the outer diameter side toward the inner diameter side, and an end surface portion extending radially inward from the inner diameter end of the outer diameter side taper portion 7a. 7b. The needle 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. If the amount of movement of the roller 1 relative to the cage 5 can be ensured, the inner diameter side taper portion 6a and the outer diameter side taper portion 7a may not be provided.

Further, as shown in FIG. 5, the needle roller 1 includes a cylindrical surface portion 10 having a constant diameter in a central region, and inclined surface portions (hereinafter also referred to as crowning portions) 11 provided on both sides of the cylindrical surface portion 10. It is a crowning roller.

Generally, a roller bearing has an advantage that a load capacity is high because a roller as a rolling element is in line contact with a raceway surface. On the other hand, surface pressure concentration called edge load is likely to occur at the end of the effective contact portion between the roller and the raceway surface. If this is excessive, attention should be paid to shortening the bearing life. In order to avoid the occurrence of edge load, when designing roller bearings, a crowning with a non-linear busbar shape is formed on at least one of the outer circumferential surface (rolling surface), outer ring raceway surface, or inner ring raceway surface of the roller. It is common to do. It is preferable that the crowning shape of the crowning is represented by a logarithmic curve as the crowning that suppresses the edge load and makes the contact surface pressure uniform. For this reason, it is preferable that the needle roller 1 of the needle roller 30 with a retainer according to the present embodiment has, for example, a logarithmic crowning shape having a shape approximated by a logarithmic function.

Here, the logarithmic crowning applied to the needle roller 1 will be described. The buses of the crowning portions 11b and 11b of the rolling surface 1a of the needle roller 1 are obtained based on a logarithmic curve of logarithmic crowning expressed by the following equation (Equation 1). As the logarithmic crowning equation, the one described in Japanese Patent No. 4429842 of the present applicant is cited. In this case, the contour line of the crowning in the axial cross section of the roller bearing is defined as y-axis where the generatrix of any of the inner ring raceway surface, the outer ring raceway surface or the roller rolling surface is the y-axis, and the z-axis is perpendicular to the generatrix. This is expressed by Equation 1 using the z coordinate system.

In Equation 3, A is expressed by the following Equation 4, and a is the length from the origin on any of the inner ring raceway surface, outer ring raceway surface or roller rolling surface to the end of the effective contact portion. is there.

Design parameters K ₁ , K _2, and z _{m in the} above logarithmic crowning equation are designed. A mathematical optimization method for logarithmic crowning is described. An optimal logarithmic crowning can be designed by appropriately selecting K ₁ and z _m in a functional expression representing logarithmic crowning after defining the design parameter K ₂ . Crowning is generally designed to reduce the maximum surface pressure or stress at the contact. Here, it is considered that the rolling fatigue life occurs according to the yield condition of Mises, and K ₁ and z _m are selected so as to minimize the maximum value of the equivalent stress of Mises. K ₁ and z _m can be selected using an appropriate mathematical optimization method. Various algorithms for mathematical optimization methods have been proposed. One of the direct search methods is that optimization can be performed without using the derivative of the function. Useful when functions and variables cannot be directly represented by mathematical expressions. Here, K ₁ and z _m are obtained by using Rosenblock method which is one of direct search methods.

The shape of the crowning

portions

11, 11 of the needle 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 kept small even when the shaft on which the needle roller 30 with cage is mounted has an inclination or the like, and the life can be extended. However, the logarithmic shape is not limited to the above mathematical 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 machining. Here, the barrel processing is a process in which needle rollers and an abrasive are put in a basket and crowning portions are formed at both ends of the needle rollers. When the crowning portion 11 of the needle roller 1 is crowned by barrel machining, the drop amount from the outer peripheral surface of the cylindrical surface portion 10 (the radially outermost end of the cylindrical surface portion 10) is, for example, 0.5 μm. The boundary portion 12 is preferable. In addition, when forming a crowning part by barrel processing, the linear part (cylindrical surface part 10) of the needle roller 1 will also drop in a trace amount on a process, and the definition of a linear part will become difficult. For this reason, it is preferable to define the position which dropped 0.5 micrometer from the outermost diameter part of the needle roller 1 as a crowning start point (boundary part of the cylindrical surface part 10 and the inclined surface part 11).

As shown in FIG. 5, in the needle roller 1, the axial length L1 of the cylindrical surface portion 10 in the center region is set to 40 to 70% of the total length (roller axial length) L of the needle roller 1. When the crowning shape of the needle roller 1 is a logarithmic shape, the amount of drop is small at the beginning of crowning, and the drop amount increases markedly as it approaches the end. Therefore, if the straight portion (cylindrical surface portion) 10 is too short, that is, the crowning length is too long, the drop amount increases on the side closer to the end portion. For this reason, processing takes time and becomes expensive. On the other hand, when the straight portion (cylindrical surface portion) 10 is too long, that is, when the crowning length is too short, the drop amount becomes small. For this reason, when the bearing is inclined, an edge load is likely to occur. Here, the drop amount is a reduction amount in the radial direction caused by crowning.

Therefore, by setting the axial length L1 of the cylindrical surface portion 10 in the central region to 40 to 70% of the total length (roller axial length) L of the needle roller 1, even when the bearing inclination is small, the contact surface pressure is reduced. Is not excessive, and even when the inclination of the bearing is large, edge load is less likely to occur.

That is, as shown in the following Table 1, 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 bearing tilt is small, but the bearing tilt is small. If it is large, edge loading tends to occur. In addition, if the straight length of the straight portion (cylindrical surface portion) 10 exceeds 70%, the contact surface pressure does not become excessive when the bearing tilt is large, but when the bearing tilt is small, the contact surface pressure is small. It tends to be excessive.

By the way, in the needle roller bearing 30 with a cage, a welded cage is employed as the cage 2 in order to increase the load capacity (in order to increase the roller length and the number of rollers as much as possible). The manufacturing process of the welded cage is roughly as follows.
(A) A strip-shaped steel material obtained by shearing a cold-rolled steel plate such as SPC having good formability to a predetermined width with a slitter or the like is used as a material.
(B) The strip-shaped steel material is pressed to form a basic cross-sectional shape (M-shaped or V-shaped) of the cage.
(C) A pocket is punched and formed at a predetermined pitch in the length direction of the strip steel material. Thereafter, the strip steel material is cut into a predetermined length in consideration of the welding allowance at both ends.
(D) The strip steel material is bent into an annular shape.
(E) Both ends are butt welded.
Thereafter, heat treatment such as nitrocarburizing or carburizing and quenching is performed to remove strain generated by welding, and a hardened layer is formed on the surface of the cage.

The welded cage manufactured in this way uses a thin strip steel material to bend in an annular shape. For this reason, it is possible to make the width dimension of the punching remaining portion, which becomes a column part formed between adjacent pockets, relatively small, and to make the pocket length dimension corresponding to the roller length relatively large Is possible. Therefore, if a welded cage is used, the roller length can be increased and the number of rollers can be increased. Further, by making the cage 2 a welded cage, the pocket 5 is radially expanded from the inner diameter side toward the outer diameter side, and it is effective that the needle roller 1 contacts the connecting portion of the pocket 5. 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 disposed so as not to overlap in the axial direction, and the boundary portion between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1. 12 is arranged so as not to overlap with the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 at the axial position. For this reason, an oil film near the crowning start point (boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) where the contact stress is maximum when the bearing is tilted can be secured, and the occurrence of wear or peeling at the crowning start point It can be suppressed and has a long life.

The crowning start point of the needle roller 1 (the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) was made not to contact the cage 2. By doing so, an oil film at the crowning start point can be secured, and the occurrence of wear or peeling at the crowning start point can be suppressed, resulting in a long life.

By preventing the crowning start point (boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) of the needle roller 1 from contacting the cage 2, the roundness of the crowning portion (inclined surface portion 11) is excessively reduced. There is no need to do so, and wear of the starting point (the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) can be prevented. Specifically, the roundness of the crowning portion (inclined surface portion 11) of the needle roller 1 may be set to 0.6 to 2.0 μm.

Also, by using a logarithmic shape for the crowning shape of the needle roller 1, the contact surface pressure can be kept small even when there is an inclination of the shaft, etc., resulting in a longer life.

Incidentally, as shown in FIG. 1, 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 is disposed on the outer side of the pitch circle diameter PCD. It is arranged on the inner diameter side. Thus, the outer diameter side retaining stopper 6 and the inner diameter side retaining stopper 7 are set so as not to overlap in the axial direction. That is, the outer diameter side retaining stopper 6 is offset to the outer side in the axial direction with respect to the inner diameter side retaining stopper 7.

Further, as shown in FIG. 1, in the state where the needle roller 1 is disposed in the pocket 5 of the cage 2, the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller 1 is an outer diameter portion. This corresponds to the inclined portion 4c that connects 4a and the inner diameter portion 4b. For this reason, the boundary portion 12 of the needle roller 1 is in a state where it does not overlap the outer diameter side retaining stopper 6 and the inner diameter side retaining stopper 7 in the axial direction. That is, the boundary portion 12 is offset with respect to the outer diameter side retaining member 6 and the inner diameter side retaining member 7.

In this case, the inclined portion 4c that connects the outer diameter portion 4a and the inner diameter portion 4b constitutes a connection portion 8 that connects the outer diameter side retaining member 6 and the inner diameter side retaining member 7, and this connecting portion 8 is shown in FIG. It is set as the thin shape shown in FIG. In other words, the inclined portion 4c is provided with a notched portion (soaking portion) 9 having an unequal side triangle shape. The boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the needle roller is disposed between the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 of the cage 2, that is, at a position corresponding to the connection portion 8. Further, the boundary portion 12 is set so as not to contact the connecting portion 8.

Incidentally, the cage 2 of the needle roller 30 with the cage shown in FIG. 2 was called the M-type cage as described above, but as shown in FIG. 6, the cage 2 was called the V-type cage. It may be. The M-type cage shown in FIG. 2 has an inward flange 3a at the outer end of the annular portion 3, whereas what is called a V-type cage as shown in FIG. It is something that does not have. For this reason, in this embodiment, the M-type cage shown in FIG. 2 or the V-type cage shown in FIG. 6 may be used.

By the way, the needle roller 30 with a retainer of the present embodiment can be used in a support structure for supporting a planetary gear mechanism S as shown in FIG. 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, and a plurality of planets meshing with the internal gear 15 and the sun gear 16. A gear (pinion) 17 is provided.

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. Each planetary gear 17 is rotatably supported on a pinion shaft 18a of a carrier 18, as shown in FIG.

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 the cage supports the planetary gear 17 on the pinion shaft 18a so as to be rotatable. A support structure for supporting the planetary gear mechanism S can be configured.

The retainer 2 of the needle roller 30 with a retainer has an outer diameter surface of the pinion shaft 18a as an inner raceway surface and an inner diameter surface of the planetary gear 17 as an outer raceway surface. The cage 2 constitutes an outer diameter guide surface 20 (see FIG. 1) that comes into contact with the outer raceway surface constituted by the inner diameter surface of the planetary gear 17 at both axial ends thereof. Here, the outer diameter guide surface 20 is a range H starting from the annular portion 3 and extending to a part of the column portion of the outer peripheral surface of the cage 2, as shown in FIG. At the time of rotation, the retainer 2 is in guiding contact with the inner peripheral surface (inner diameter surface) of the pinion (planetary gear) 17 at the outer diameter guide surface 20. For this reason, this cage 2 is of a so-called outer ring guide type.

By the way, as a cage guide type, a raceway guide is preferable to a roller guide from the viewpoint of safety of cage motion under a high speed motion, and further, an outer ring than an inner ring guide from the viewpoint of lubricating oil behavior due to centrifugal force. A guidance format is preferred.

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 second oil passage hole 18bb extending from the first oil passage hole 18a in the radial direction of the pinion shaft 18a. The second oil passage hole 18bb communicates the first oil passage hole 18ba and the outer peripheral surface of the pinion shaft 18a. The second oil passage hole 18bb is provided at a position that overlaps the needle roller 30 with a cage in the axial direction. Lubricating oil is drawn in through an oil passage hole 18b formed inside the pinion shaft 18a and guided to the outer peripheral surface of the pinion shaft 18a, whereby the needle roller 30 with a cage is lubricated.

Since the retainer 2 has the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7, it is possible to effectively prevent the needle roller 1 from falling off. Further, the outer diameter of the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11 of the roller 1 does not overlap with the roller stopper for preventing the roller 1 from dropping out of the cage 2 to the outer diameter in the axial direction. Since it arrange | positions so that it may become the axial direction center side rather than the side roller stopper part 6, a high edge surface pressure part cannot become a lubricous defect easily. In addition, since the boundary part between the cylindrical surface part and the inclined surface part of the roller is arranged so as not to overlap the outer diameter side roller stopper and the inner diameter side roller stopper at the axial position, the contact stress becomes maximum when the bearing is inclined. An oil film can be secured in the vicinity of the crowning start point (near the boundary portion between the cylindrical surface portion and the inclined surface portion), and the occurrence of wear and peeling at the crowning start point can be suppressed, thereby extending the life. Moreover, even if the crowning length is long, it is not difficult to assemble when assembling to the shaft or the housing inner diameter.

Further, the inner diameter side roller stopper 7 is not disposed on the inner diameter side of the outer diameter side roller stopper 6, and a space for the retainer 2 is provided, so that both the roller stoppers 6 and 7 (both inner diameter sides) are provided. The axial position on the outer diameter side can reduce the inflow of lubricating oil. In particular, in the planetary gear mechanism support structure, when the cage 2 is an outer ring guide type, the area of the contact guide portion between the outer diameter guide surface of the cage 2 and the inner peripheral surface of the pinion shaft 18 is large. The oil permeability to the end of 1 and the oil permeability of the lubricating oil between the outer diameter guide surface of the cage 2 and the inner peripheral surface of the pinion shaft 18 are important. Therefore, it is effective to use the needle roller 30 with a cage. Moreover, in the above-described 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 needle roller 1 are arranged so as not to overlap at the axial position. Even with this setting, when the bearing is tilted, it is possible to secure an oil film in the vicinity of the crowning start point where the contact stress is maximum (near the boundary portion between the cylindrical surface part and the inclined surface part). Generation | occurrence | production of peeling etc. can be suppressed and lifetime improvement can be aimed at.

Furthermore, the boundary portion 12 between the cylindrical portion 10 and the inclined portion 11 of the roller 1 is arranged so as to be on both ends in the axial direction with respect to the inner diameter side roller stopper portion 7, and the high edge surface pressure portion causes poor lubrication. It becomes difficult to become. The axial position of the boundary portion 12 between the cylindrical portion 10 and the inclined portion 11 of the roller 1 is a connecting portion (inclined portion) 8 between the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 of the cage 2. The portion 8 is configured not to contact the cage 2. As a result, an oil film at the crowning start point can be secured and the occurrence of wear or peeling at the crowning start point can be suppressed, thereby extending the life. Further, it is not necessary to excessively reduce the roundness of the crowning portion (inclined surface portion), and the wear at the crowning start point can be blocked. By preventing the crowning start point (boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) of the needle roller 1 from contacting the cage 2, the roundness of the crowning portion (inclined surface portion 11) is excessively reduced. There is no need to do so, and wear of the starting point (the boundary portion 12 between the cylindrical surface portion 10 and the inclined surface portion 11) can be prevented. Specifically, the roundness of the crowning portion (inclined surface portion 11) of the needle roller 1 may be set to 0.6 to 2.0 μm.

For this reason, in this embodiment, the high edge surface pressure portion is unlikely to be poorly lubricated, the occurrence of wear and peeling can be suppressed, and the deterioration of the inflow property of the lubricating oil can be effectively prevented. For this reason, the suitable needle roller 30 with a retainer excellent in durability can be provided. Moreover, even when the crowning length of the roller 1 is increased, the assembly is excellent when assembled to the shaft or the housing inner diameter.

Further, since the thinning portion 9 is provided in the cage 2, the lubricating oil is guided between the outer diameter guide surface 20 and the inner peripheral surface of the planetary gear 17 through the thinning 9. Thereby, an oil film can be formed between the outer peripheral surface (outer diameter guide surface 20) of the cage 2 and the inner peripheral surface of the planetary gear 17, and the friction can be reduced. This contributes to the improvement of the service life.

By the way, the cage 2 is formed by rounding a steel plate from which a hole to be the pocket 5 is punched, and integrating the joined portions by welding. That is, the cage 2 is formed of a welded joint of steel plates from which the pockets 5 are punched. If formed in this way, the pockets 5 radially expand from the inner diameter side toward the outer diameter side, and it is possible to effectively prevent the rollers 1 from coming into contact with the connecting portions of the pockets 5 of the cage 2.

Further, as shown in FIG. 9, the needle roller 30 with the cage of the present embodiment may be used as a support bearing for the transmission T. That is, the needle roller 30 with a cage is a needle roller with a cage for automobiles. This transmission T is provided with two planetary gear mechanisms S, S so that rotation is sequentially transmitted. In each planetary gear mechanism S, S, a planetary gear 26 is provided on the support shaft 25 via a needle roller 30 with a cage. In this case, the outer diameter surface of the support shaft 25 is the inner raceway surface, and the inner diameter surface of the planetary gear 26 is the outer raceway surface. The cage 2 constitutes an outer diameter guide surface 20 (see FIG. 1) that contacts an outer raceway surface constituted by the inner diameter surface of the planetary gear 26 at both axial ends thereof.

When the planetary gear mechanism is used in an automobile transmission, the amount of lubricating oil is small because of the structure that enters the oil passage hole 27 of the support shaft (pinion shaft) 25 by splashing. Moreover, in the needle roller with a cage used for the transmission, it becomes a severe use environment such as an edge stress due to a centrifugal force or an uneven load. Therefore, it is optimal to use the needle roller 30 with a retainer according to the present embodiment for an automobile transmission.

Although the present embodiment has been described above, various modifications are possible without being limited to the above embodiment, and the shapes of the outer diameter side roller stopper 6 and the inner diameter side roller stopper 7 are not shown in FIG. However, it is only necessary that a part of the roller diameter is larger than the

roller stoppers

6, 6, 7 and 7 adjacent in the circumferential direction. Further, the outer diameter side roller stopper 6 may be provided on the entire outer diameter portion 4 a of the column portion 4 or may be provided on a part of the outer diameter portion 4 a of the column portion 4. . Further, the inner diameter side roller stopper 7 may be provided on the entire inner diameter portion 4b of the column portion 4 or may be provided on a part of the inner diameter portion of the column portion. The needle roller 30 with a cage may be a single row or a double row.

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

DESCRIPTION OF SYMBOLS 1 Needle roller 2 Cage 3 Annular part 3a Flange 4 Column part 5 Pocket 6 Outer diameter side roller stopper 7 Inner diameter side roller stopper 8 Connection part 10 Cylindrical surface part 11 Inclined surface part 12 Boundary part 15 Internal gear 16 Sun gear 17 Planetary gear 18 Carrier 18a Pinion shaft 20 Outer diameter guide surface 30 Needle roller S with cage S Planetary gear mechanism PCD Pitch circle diameter

Claims

In a needle roller with a cage comprising a plurality of needle rollers and a cage,
The retainer has a pair of annular portions spaced apart in the axial direction, and a plurality of pillars extending in the axial direction and connecting the annular portions,
The cage includes an outer diameter side roller stopper provided at both ends in the axial direction on the outer diameter side of the roller pitch circle diameter, and an inner diameter side provided on the inner diameter side of the roller pitch circle diameter in the central part in the axial direction. The outer diameter side roller stopper and the inner diameter side roller stopper are arranged so as not to overlap in the axial direction.
The needle roller is a crowning roller having a cylindrical surface portion having a constant diameter in the center region and inclined surface portions on both sides of the cylindrical surface portion,
The boundary portion between the cylindrical surface portion and the inclined surface portion is disposed between the outer diameter side roller stopper and the inner diameter side roller stopper, and the boundary portion between the cylindrical surface portion and the inclined surface portion is the retainer. Needle roller with cage, characterized by non-contact.
The retainer further includes an inclined connection portion that connects the outer diameter side roller stopper and the inner diameter side roller stopper,
The needle roller with a retainer according to claim 1, wherein the inclined connecting portion has a thin shape that avoids interference with the needle roller.
Between the column portions adjacent to each other in the circumferential direction of the cage, a pocket in which the needle rollers are arranged is formed,
The needle roller with retainer according to claim 1 or 2, wherein the pocket is radially expanded from the inner diameter side to the outer diameter side.
The needle roller with a cage according to claim 3, wherein the cage is a welded joint of a steel plate with the pocket punched out.
The needle roller with a cage according to any one of claims 1 to 4, wherein the needle roller has a logarithmic crowning shape approximated by a logarithmic function.
The needle roller is a needle roller of a crowning roller having a logarithmic crowning shape approximated by a logarithmic function. One of the generatrixes of the surface is the y-axis, and the z-axis is taken in the direction perpendicular to the generatrix, and is expressed by Equation 1, and the axial length of the cylindrical surface portion is 40% of the total roller length. The needle roller with a retainer according to claim 5, characterized by being -70%.

However, in Equation 1, A is expressed by the following Equation 2, and a is the length from the origin taken on any of the inner ring raceway surface, outer ring raceway surface or roller rolling surface to the end of the effective contact portion. That's it.
7. The cage according to claim 1, wherein the retainer is an M-type having an inward flange at an outer end of the annular portion or a V-type having no inward flange at an outer end of the annular portion. A needle roller with a cage according to claim 1.
A planetary gear provided with an internal gear, a sun gear disposed at the center of the internal gear, a plurality of planetary gears meshed with the internal gear and the sun gear, and a carrier that supports the planetary gear A planetary gear mechanism support structure for supporting a gear mechanism,
The planetary gear is rotatably supported by a pinion shaft provided on the carrier via a rolling bearing, and the rolling bearing is provided on the needle roller with a cage according to any one of claims 1 to 7. A planetary gear mechanism support structure characterized in that it is configured as described above.
The outer diameter surface of the pinion shaft is the inner raceway surface, the inner diameter surface of the planetary gear is the outer ring raceway surface, and the cage used for the needle roller with cage is an inner diameter of the planetary gear at both ends in the axial direction. An oil passage hole that is in contact with an outer ring raceway surface constituted by a surface and opens in an inner raceway surface constituted by an outer diameter surface of the pinion shaft is provided inside the pinion shaft. 9. The planetary gear mechanism support structure according to 8.
The planetary gear mechanism support structure according to claim 8 or 9, wherein the planetary gear mechanism support structure is used for an automobile transmission.