JPH09203414A - Holder for roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve rolling and sliding properties of a roller on the surface such as the sliding contact surface by providing a macromolecular member into which an extreme-pressure additive is impregnated, on the inner wall of a pocket part of a holder, and by adding this extreme-pressure additive to the surface of a roller, to be extruded into lubricating oil. SOLUTION: A needle roller bearing 21 is composed of a holder 22 of a cylindrical body and a needle roller 10 retained within a pocket part of the holder 22. A small recessed depression part 23 in a diffused state is formed on four inner walls 22D constituting the pocket part. A macromolecular member 24 into which an extreme-pressure additive is impregnated, is embedded within the recessed depression part 23. The extreme-pressure additive attaches directly to the surface of the needle roller 10. A molecular absorption film and a reactive lubrication film can be formed by the extreme-pressure additive on the sliding contact surface of the needle roller 10 to thereby prevent abrasion of the sliding contact surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller bearing retainer for rotatably holding a plurality of rollers in a roller bearing using a plurality of rollers as rolling elements.

[0002]

2. Description of the Related Art Generally, among bearings that rotatably support a shaft, a roller bearing that uses a plurality of rollers (cylindrical rollers, needle rollers, etc.) as rolling elements has a substantially cylindrical shape as a whole. And a plurality of rollers rotatably held by the holder.

Therefore, a case where the above-described conventional roller bearing is used in the planetary gear speed reduction mechanism shown in FIG. 16 will be described as an example.

In the drawings, reference numeral 1 denotes a planetary gear speed reduction mechanism. The planetary gear speed reduction mechanism 1 has a cylindrical housing 3 in which an internal gear 2 is formed on the inner peripheral side over the entire circumference, and the housing 3. The sun gear 4 attached to the output shaft (none of them is shown) of an externally arranged motor meshes with the sun gear 4 and the internal gear 2 of the housing 3, and rotates around the sun gear 4. A plurality of planetary gears 5 (only one is shown) revolving while revolving, and a carrier 6 that rotatably supports each planetary gear 5 via needle roller bearings 8 and the like described later.

Here, the carrier 6 comprises an internal tooth 6A formed on the inner peripheral side, and an upper pin support portion 6B and a lower pin support portion 6C which face each other with the planetary gear 5 interposed therebetween. The pin 7 is supported between the support portion 6B and the lower pin support portion 6C.

Reference numeral 8 denotes a needle roller bearing which is provided between the planetary gear 5 and the pin 7 and rotatably supports the planetary gear 5 with respect to the carrier 6. The needle roller bearing 8 has a planetary outer peripheral side. A cylindrical retainer 9 fitted into the bearing hole 5A of the gear 5 and having a pin 7 inserted into the inner peripheral side thereof, and a plurality of needle rollers 1 rotatably retained in the retainer 9 at equal intervals.
It is composed of 0, 10 ,.

Here, the needle roller bearing 8 and the cage 9 will be described with reference to FIGS.

The retainer 9 is formed as a cylindrical body, and is provided with a pair of annular portions 9A, 9A spaced apart in the axial direction and substantially equal intervals between the annular portions 9A,
A plurality of support columns 9B, 9B, ... Which connect the respective annular portions 9A.
, A plurality of pockets 9C, 9C, ... Formed as rectangular openings for accommodating the needle rollers 10 and located between the respective pillars 9B, and rotatably holding the needle rollers 10. Therefore, among the inner walls 9D, 9D, ... Of the pocket portion 9C, from the inner peripheral side and the plurality of protruding portions 9E, 9E ,. Become. Further, oil passages 9F, 9F, ... Are formed between the inner wall 9D of each pocket portion 9C and the needle roller 10. The oil passages 9F form a gap between the pocket 9C and the needle roller 10. By circulating it easily, the lubricity is improved.

Each needle roller 10 held by the cage 9 revolves around the pin 7 while rotating between the planet gear 5 and the pin 7 so that the planet gear 5 moves to the pin 7.
It is designed to rotate smoothly against.

Reference numerals 11 and 11 denote annular slide plates provided between the axial end surface of the needle roller bearing 8 and the upper pin support portion 6B and the lower pin support portion 6C of the carrier 6. The sliding plate 11 improves the slidability of the axial end surface of the needle roller bearing 8 and promotes smooth rotation of each planetary gear 5 with respect to the carrier 6.

Reference numeral 12 denotes an output shaft rotatably supported in the housing 3 via bearings (not shown), and the output shaft 12 is coaxial with the sun gear 4 via a plate 13 as a sliding plate. It is located above. A tooth portion 12A is formed on the outer circumference of the upper end side of the output shaft 12, and the tooth portion 12A meshes with the inner teeth 6A of the carrier 6. In addition, output shaft 1
2 may be a sun gear that constitutes the second stage planetary gear reduction mechanism.

The planetary gear speed reduction mechanism 1 configured as described above
In the above, when the sun gear 4 is rotated by driving the motor, the planet gears 5 are rotated by the sun gear 4 and the housing 3.
The sun gear 4 revolves around the sun gear 4 while rotating with the inner gear 2 and the carrier 6 rotates around the sun gear 4 as the planet gears 5 revolve. This allows carrier 6
Output shaft 12 connected to the internal tooth 6A of the vehicle through a tooth portion 12A
The rotation of the output shaft of the motor is transmitted after being decelerated, and the torque of the output shaft 12 increases according to the reduction ratio.

[0013]

However, in the planetary gear speed reduction mechanism 1 having the needle roller bearing 8 according to the prior art described above, the sliding contact surface between the pin 7 and the needle roller 10 and the needle roller 10 and the planet during operation are in operation. The sliding contact surface of the gear 5 with the bearing hole 5A causes rolling contact and sliding contact under high load. For this reason, in order to obtain a good lubricating state, the lubricating oil used is a base oil mixed with an extreme pressure additive. By using this extreme pressure additive, a molecular adsorption film or a reactive lubrication film is formed on the sliding contact surface to improve the lubricity of the sliding contact surface, resulting in wear of the sliding contact surface, fatigue wear (pitting), peeling, etc. To prevent damage.

However, there are various lubricating oils depending on the type and amount of the extreme pressure additive to be added to the base oil and the manner of blending, and any lubricating oil is mixed with the extreme pressure additive before use. However, there is a problem that the price becomes high.

The present invention has been made in view of the above-mentioned problems of the prior art. Lubrication of the rollers is achieved by impregnating the cage with the extreme pressure additive rather than by blending the lubricant with the extreme pressure additive. It is an object of the present invention to provide a cage for a roller bearing which can improve the rolling property and the sliding property under a high load.

[0016]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a pair of annular portions which are axially separated from each other, and is arranged with a space between each annular portion. Formed as a cylindrical body from a plurality of pillars connecting the respective annular portions and a plurality of pockets respectively provided between the pillars so as to rotatably support the rollers. In the container, a concave portion is formed on the inner wall of the pocket portion, and a polymer member impregnated with an extreme pressure additive is embedded in the concave portion.

With the above construction, the extreme pressure additive impregnated in the polymer member is directly adhered to the surface of the roller at the portion in contact with the polymer member, and the roller is slid by the extreme pressure additive. A molecular adsorption film or a reactive lubricating film is formed on the contact surface to enhance the lubricity on the sliding contact surface.

According to the second aspect of the present invention, the concave portion is formed in a plurality of dimples or long grooves provided on the inner wall of the pocket portion.

With the above structure, it is possible to increase the contact portion between the polymer member and the lubricant member and the contact portion between the polymer member and the lubricating oil, so that the sliding contact and the rolling contact of the rollers can be made good.

According to the third aspect of the present invention, the polymer member embedded in the recess is made of a foamed polymer material in a porous form, and the porous foamed pores are impregnated with the extreme pressure additive. There is something.

With the above structure, the polymer member is formed into a porous sponge so that the extreme pressure additive is easily impregnated into the foamed pores, and the extreme pressure additive allows the molecular adsorption film or the molecular adsorption film on the sliding contact surface of the roller. A reactive lubricating film is formed to improve the lubricity of the sliding contact surface.

According to a fourth aspect of the present invention, a pair of annular portions that are spaced apart from each other in the axial direction, and a plurality of pillar portions that are arranged with a gap between the respective annular portions and that connect the respective annular portions, A roller bearing retainer formed as a cylindrical body from a plurality of pocket portions respectively provided between the support columns to rotatably support the rollers, wherein the pair of annular portions, each support portion, and each The pocket portion is characterized by being integrally formed as a cylindrical body from a polymer material impregnated with an extreme pressure additive.

With the above structure, the extreme pressure additive impregnated in the polymer member of the retainer is directly adhered to the surface of the roller at the portion in contact with the retainer, and the extreme pressure additive is used to A molecular adsorption film or a reactive lubricating film is formed on the sliding contact surface of the to improve the lubricity of the sliding contact surface.

According to a fifth aspect of the present invention, a pair of annular portions that are spaced apart from each other in the axial direction, and a plurality of pillar portions that are arranged with a gap between the respective annular portions and that connect the respective annular portions, A roller bearing retainer formed as a cylindrical body from a plurality of pocket portions respectively provided between the support columns to rotatably support the rollers, wherein the pair of annular portions, each support portion, and each The pocket part is characterized in that it is integrally foam-molded in a porous manner with a foamed polymer material, and the extreme pressure additive is impregnated into the porous foam hole.

With the above-mentioned constitution, the polymeric material can be made into a sponge shape so that the extreme pressure additive can be easily impregnated into the foaming pores, and the extreme pressure additive allows the molecular adsorption film or the reaction on the sliding surface of the roller. A lubricating film is formed to improve the lubricity of the sliding contact surface.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIGS. 1 to 15 show examples according to the present invention. In the embodiment, the same components as those of the conventional technique shown in FIGS. 16 to 19 are designated by the same reference numerals and the description thereof will be omitted.

First, FIGS. 1 to 4 show a first embodiment.

In the figure, reference numeral 21 denotes a needle roller bearing having a retainer according to this embodiment. The needle roller bearing 21 rotates with a cylindrical retainer 22 described later and the retainer 22 at equal intervals. A plurality of needle rollers 10, 10,
….

Reference numeral 22 denotes a retainer according to this embodiment. The retainer 22 has a pair of annular portions 22A, 22A which are spaced apart from each other in the axial direction, and the annular portions 22A have substantially equal intervals. Plural strut portions 22B, 22B, ... Arranged and connecting between the annular portions 22A, and the strut portions 22B.
A plurality of pocket portions 22C, which are formed as opening portions in a rectangular shape for accommodating the needle roller 10,
22C, ..., In order to hold the needle roller 10 rotatably,
In the inner walls 22D, 22D, ... Of the pocket portion 22C, a plurality of protrusions 22E, 22E ,. Also,
An oil passage 22F is formed between the inner wall 22D of each pocket portion 22C and the needle roller 10, and the lubricating oil is circulated in the gap between the pocket 22C and the needle roller 10 by each oil passage 22F. ing.

Denoted by 23, 23, ... are dimples formed dispersively on the four surfaces forming the inner wall 22D of the pocket 22C, and each of the dimples 23 is formed in a small diameter hemisphere.

Reference numerals 24, 24, ... Represent a hemispherical polymer member, and each polymer member 24 is embedded in each recess 23, and its material is, for example, polyethylene, polypropylene, polybutylene, polystyrene, It is made of diallyl phthalate resin, phenol resin, polyurethane, thermoplastic elastomer, etc.

Further, reference numerals 25, 25, ... In FIG. 4 denote extreme pressure additives, and each extreme pressure additive 25 is each polymer member 2 described above.
4 is impregnated. Here, the extreme pressure additive 25 is used to improve the anti-friction load performance (extreme pressure performance) as a boundary lubrication condition, and the extreme pressure additive 25 is, for example, a phosphorus-based extreme pressure additive, sulfur Extreme pressure additives, chlorine extreme pressure additives, organometallic extreme pressure additives and the like are known.

Then, the phosphorus-based extreme pressure additive decomposes on the friction surface and reacts with iron to form iron phosphide, and this iron phosphide and iron become eutectic gold, lowering the melting point, and the friction surface local It melts and becomes smooth. Further, the sulfur-based extreme pressure additive forms an iron sulfide film, and the chlorine-based extreme pressure additive forms an iron chloride film. Furthermore, as the organometallic extreme pressure additive, zinc dialkyldithiophosphate (ZnDTP) is typically known.

The cage 22 according to the present embodiment is as described above, and the needle roller bearing 21 having the cage 22 is different from the prior art in the basic operation of the planetary gear reduction mechanism 1. Absent.

However, according to the present embodiment, a plurality of dimple-shaped recesses 23 are formed in each inner wall 22D of each pocket 22C of the cage 22 which constitutes the needle roller bearing 21, and each recess is formed. Since the polymer member 24 impregnated with the extreme pressure additive 25 is embedded in 23, the needle roller 10 is brought into direct contact with the polymer member 24 of the inner wall 22D by driving the reduction gear mechanism 1, The extreme pressure additive 25 impregnated in the polymer member 24 exudes and locally adheres to the surface of the needle roller 10.

Therefore, the extreme pressure additive 25 adhering to the needle roller 10 causes sliding contact between the needle roller 10 and the bearing hole 5A of the planetary gear 5, and between the needle roller 10 and the pin 7. A molecular adsorption film or a reactive lubricating film can be formed on the surface, the rolling property and the sliding property on each sliding contact surface can be improved, and the abrasion due to pitting, metal peeling, etc. can be reduced.

As a result, due to the action of the extreme pressure additive 25 with which the polymer member 24 is impregnated, the sliding contact surface between the needle roller 10 and the bearing hole 5A of the planetary gear 5, the needle roller 10 and the pin 7 are formed.
It is possible to lubricate the sliding contact surface between the sliding contact surface and the like, prevent wear, pitting (fatigue wear), metal peeling, etc. of each sliding contact surface, and thus extend the life of the planetary gear reduction mechanism 1.

Further, even when the lubricating oil used is one in which the extreme pressure additive 25 is not mixed, the extreme pressure additive 25 impregnated in the polymer member 24 with this lubricating oil as a base oil seeps out, Lubricating oil in which the extreme pressure additive 25 is mixed can be used. As a result, by using the cage 22 according to the present embodiment, it is possible to make the lubricating oil of a grade lower than the usage level have the same properties as those of a higher grade, and to reduce the cost of the lubricating oil. it can.

Further, FIG. 5 shows a second embodiment according to the present invention. The feature of the present embodiment is that the polymer member 24 according to the first embodiment is formed of a foamed polymer material, and the polymer member is formed. Two
4 ', and the extreme pressure additive 25' is impregnated into the foamed pores of the polymer member 24 'which are in the form of porous sponge. In this case, it is preferable that the porous polymer member 24 'is formed of foamed resin with open cells.

With this structure, the extreme pressure additive 25 'can be effectively impregnated into the foaming holes of the polymer member 24', and the extreme pressure additive 25 'can be easily incorporated into the lubricating oil. It can be exuded to form a molecular adsorption film or a reactive lubricating film on the sliding contact surface, and the lubricity on the sliding contact surface can be further enhanced.

Next, a third embodiment of the present invention will be described with reference to FIGS.
The feature of this embodiment is that the concave portion formed on the inner wall of the pocket portion is formed as a long groove having a rectangular cross section.
The polymer member to be embedded in the recess is formed in a rectangular shape.

In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 31 indicates a needle roller bearing having a cage according to the present embodiment, and the needle roller bearing 31 is used instead of the needle roller bearing 21 described in the first embodiment. The retainer 32 according to the present embodiment is different from the retainer 32 in the first embodiment in that the shape of the recessed portion 33 formed in the retainer 32 and the polymer member 34 provided in the recessed portion 33 will be described later. ing.

Here, the retainer 32 is formed in a cylindrical shape, and has a pair of annular portions 32 that are spaced apart from each other in the axial direction.
A, 32A and a plurality of pillar portions 32B, 32B, ..., Which are arranged at substantially equal intervals between the annular portions 32A and connect the annular portions 32A, and between the pillar portions 32B, respectively. A plurality of pocket portions 32C, 32, which are formed as rectangular openings for accommodating the needle rollers 10.
, And a plurality of protrusions 32E projectingly provided on the inner wall 32D of each of the support columns 32B axially opposed to each other in the inner walls 32D, 32D, of the pocket portion 32C in order to rotatably hold the needle roller 10. , 32E ,. An oil passage 32F is formed between the inner wall 32D of each pocket portion 32C and the needle roller 10.

33, 33, ... denote long groove-like recesses,
Each of the concave portions 33 has an inner wall 32D of the pocket portion 32C.
Is formed in a rectangular shape in the middle of the thickness direction of the four surfaces, that is, in the portion where the needle roller 10 is in sliding contact with the pocket portion 32C.

Reference numerals 34, 34, ... Represent a polymer member formed in a rectangular shape, each polymer member 34 is embedded in each recess 33, and each polymer member 34 has a plurality of poles. The pressure additives 35, 35, ... Are impregnated.

Also in the needle roller bearing 31 using the retainer 32 according to this embodiment having the above-mentioned structure,
It is possible to obtain substantially the same effect as the embodiment of
Since the polymer member 34 is embedded in a rectangular shape in a portion where the needle roller 10 and the pocket portion 32C are in contact with each other, the extreme pressure additive 35 in the polymer member 34 is locally attached to the surface of the needle roller 10. It is possible to improve the rolling property and the sliding property of the sliding contact surface of the needle roller 10 more reliably than in the first embodiment, and it is possible to reduce wear such as pitching and metal wear.

Furthermore, FIGS. 9 to 11 show a fourth embodiment of the present invention.
The present embodiment is characterized in that the recessed portion formed on the inner wall of the pocket portion is formed as an annular groove extending to the inner walls of four faces, and the polymer member embedded in the recessed portion is formed in a ring shape. There is something I did.

In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 41 indicates a needle roller bearing having a cage according to the present embodiment. The needle roller bearing 41 is used in place of the needle roller bearing 21 described in the first embodiment. The retainer 42 according to the present embodiment is different from that of the first embodiment in the shape of a recessed portion 43 formed in the retainer 42, which will be described later, and a polymer member 44 provided in the recessed portion 43. ing.

Here, the cage 42 is formed in a cylindrical shape, and has a pair of annular portions 42 which are spaced apart from each other in the axial direction.
A, 42A and a plurality of pillar portions 42B, 42B, ... Which are arranged at substantially equal intervals between the respective annular portions 42A and connect the respective annular portions 42A, and between the respective pillar portions 42B. A plurality of pocket portions 42C, 42, which are formed as rectangular openings for accommodating the needle rollers 10.
, And a plurality of protrusions 42E projectingly provided on the inner wall 42D of each of the support columns 42B axially opposed to each other in the inner walls 42D, 42D, of the pocket portion 42C in order to rotatably hold the needle roller 10. , 42E, ... An oil passage 42F is formed between the inner wall 42D of each pocket portion 42C and the needle roller 10.

Reference numerals 43, 43, ... Denote recessed portions, and each recessed portion 43 is formed as an annular groove over the four surfaces forming the pocket portion 42C.

Reference numerals 44, 44, ... Represent a ring-shaped polymer member, and each polymer member 44 is embedded by being fitted in each of the annular recesses 43.
A plurality of extreme pressure additives 45, 4 are provided in each polymer member 44.
5, ... are impregnated.

Also in the needle roller bearing 41 having the retainer 42 constructed in this way, it is possible to obtain the same effects as the first embodiment described above.

In the third and fourth embodiments described above, the polymer member 3 is also used as in the second embodiment.
It goes without saying that 4,44 may be formed as a foamed polymer material and the extreme pressure additives 35, 45 may be impregnated in the foaming holes of the polymer members 34, 44.

Next, FIGS. 12 to 14 show a fifth embodiment according to the present invention. The characteristic feature of this embodiment is that the cage is made of a polymer material impregnated with an extreme pressure additive. .

In this embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 51 indicates a needle roller bearing having a cage according to this embodiment, and the needle roller bearing 51 is used in place of the needle roller bearing 21 described in the first embodiment. Of.

Reference numeral 52 represents a retainer according to this embodiment. The retainer 52 is formed of a polymer material in a cylindrical shape, and has a pair of annular portions 52A, 52 spaced apart from each other in the axial direction.
A and a plurality of pillar portions 5 which are arranged at substantially equal intervals between the annular portions 52A and connect between the annular portions 52A.
2B, 52B, ..., and a plurality of pockets 52C, 52C, ... Formed as rectangular openings for accommodating the needle rollers 10 and located between the respective column parts 52B.
In order to hold the needle roller 10 rotatably, the pocket portion 52
From the plurality of projections 52E, 52E, ... Protrudingly provided on the inner wall 52D of each strut 52B that axially face each other on the inner walls 52D, 52D, ...
3 is integrally formed of a polymer material impregnated with 3.
In addition, the inner wall 52D of each pocket portion 52C and the needle roller 1
An oil passage 52F is formed between the oil passage 52 and zero.

Also in the needle roller bearing 51 of the present embodiment constructed as described above, it is possible to obtain the same effects as those of the first embodiment described above, and moreover, the entire cage 52 is provided with the extreme pressure additive. Since the needle roller 10 and the polymer material are in contact with each other, the extreme pressure additive 53 is directly attached to the surface of the needle roller 10 because the needle roller 10 and the polymer material are in contact with each other. It is possible to increase the number of parts where the polymer material and the lubricating oil come into contact with each other.

Further, FIG. 15 shows a sixth embodiment according to the present embodiment. The feature of the present embodiment is that the holder 52 according to the fifth embodiment is formed of a foamed polymer material and the holder 52 is formed. ′
That is, the extreme pressure additive 53 'is impregnated into the porous sponge-like portion of the retainer 52'. In this case, it is preferable that the foamed polymeric material is formed by continuous foamed resin molding.

With this structure, the extreme pressure additive 53 'can be effectively impregnated into the foaming holes of the cage 52', and the sliding contact surface of the needle roller 10 can have a molecular adsorption film or a reaction. By forming a lubricating film, it is possible to further improve the lubricity of the sliding contact surface and the like.

Although the materials of the cages 22, 32 and 42 are not specified in the first to fourth embodiments, SUS is used.
It may be formed of a metal material such as a material, polyamide (PA) 46, polyamide (PA) 66, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), etc. (however, PPS and PEEK are for high temperature) The resin material may be formed of any resin, and any material may be used as long as it can ensure the strength of the cage.

Further, in each of the above embodiments, the case where the invention is applied to the cage of the needle roller bearing has been described as an example, but the present invention is not limited to this, and for example, as a rolling element, a cylindrical roller or a tapered roller is used. It can be applied to cages for various roller bearings using the above.

Furthermore, in each of the above-mentioned embodiments, the cage of the needle roller bearing used in the portion supporting the planetary gears of the planetary gear reduction mechanism has been described as an example, but the present invention is not limited to this. For example, it can be widely applied to a roller bearing retainer that rotatably supports a rotating body such as a rotating shaft, a support pin, and a rotating rod.

[0066]

As described in detail above, according to the invention of claim 1, at the portion where the polymer member comes into contact, the extreme pressure additive impregnated in the polymer member is directly adhered to the roller,
By forming a molecular adsorption film and a reactive lubrication film, the sliding contact and rolling contact of the roller are made good, and the lubricity of the sliding contact surface is locally enhanced, and the wear of the sliding contact surface, such as pitting and peeling is reduced. can do. In addition, it is possible to use lubricants that do not contain extreme pressure additives, so that even low grade lubricants can have the same properties as high grade lubricants, thus reducing the cost of lubricants. be able to.

According to the second aspect of the present invention, since the plurality of dimples or the long grooves are provided on the inner wall of the pocket, the portion in contact with the polymer member and the portion in contact with the lubricating oil are in contact with each other. The number of parts can be increased, and the sliding contact and rolling contact of the rollers can be made good, and wear of the sliding contact surface can be reduced.

According to the third aspect of the present invention, the polymer member embedded in the recess is made of a foamed polymer material so as to be porous, thereby forming the polymer member into a porous sponge and adding the extreme pressure additive. It can be easily impregnated, a molecular adsorption film or a reactive lubricating film is formed by the extreme pressure additive, the lubricity of the sliding contact surface is enhanced, and the abrasion of the sliding contact surface can be reduced.

According to the invention of claim 4, the cage is made of a polymer material impregnated with the extreme pressure additive,
At the portion where the cage and the cage are in contact, the extreme pressure additive impregnated in the polymeric material of the cage is directly attached to the roller to make the sliding contact and the sliding contact of the needle roller good, and the sliding contact. It is possible to improve the lubricity of the surface and reduce the wear of the sliding contact surface.

According to the fifth aspect of the present invention, the cage is made of a foamed polymer material in which the extreme pressure additive is impregnated in the foam hole, so that the polymer material is formed into a porous sponge and the inside of the foam hole is formed. Is easily impregnated with an extreme pressure additive, and a molecular adsorption film or a reactive lubricating film is formed on the sliding contact surface by the extreme pressure additive,
It is possible to improve the lubricity of the sliding contact surface and reduce the wear of the sliding contact surface.

[Brief description of drawings]

FIG. 1 is an enlarged side view showing a needle roller bearing according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view as seen from the direction of arrows II-II in FIG.

FIG. 3 is a cross-sectional view showing an enlarged part a in FIG.

FIG. 4 is an enlarged sectional view showing a main part in FIG. 3;

FIG. 5 is a cross-sectional view showing a needle roller bearing according to a second embodiment of the present invention in an enlarged view of a main part at the same position as in FIG.

FIG. 6 is an enlarged side view showing a needle roller bearing according to a third embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view taken along the line VII-VII in FIG.

8 is a cross-sectional view showing an enlarged part b in FIG.

FIG. 9 is an enlarged side view showing a needle roller bearing according to a fourth embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view as seen from the direction of arrow XX in FIG.

FIG. 11 is a cross-sectional view showing an enlarged part c in FIG.

FIG. 12 is an enlarged side view showing a needle roller bearing according to a fifth embodiment of the present invention.

13 is a vertical cross-sectional view as seen from the direction of arrows XIII-XIII in FIG.

14 is a cross-sectional view showing an enlarged main part in FIG.

FIG. 15 is a cross-sectional view showing a needle roller bearing according to a sixth embodiment of the present invention in an enlarged view of a main part at the same position as in FIG.

FIG. 16 is a partially broken vertical sectional view showing a needle roller bearing according to a conventional technique used in a planetary gear reduction mechanism.

FIG. 17 is an enlarged perspective view showing a cage used in the needle roller bearing in FIG. 16.

18 is an enlarged side view showing the needle roller bearing in FIG.

FIG. 19 is a longitudinal sectional view as seen from the direction of arrows XIX-XIX in FIG. 18;

[Explanation of symbols]

 10 Needle roller 21, 31, 41, 51 Needle roller bearing 22, 32, 42, 52, 52 'Retainer 22A, 32A, 42A, 52A Annular portion 22B, 32B, 42B, 52B Strut portion 22C, 32C, 42C , 52C Pocket portion 22D, 32D, 42D, 52D Inner wall 22E, 32E, 42E, 52E Projection portion 22F, 32F, 42F, 52F Oil passage 23, 33, 43 Recessed portion 24, 24 ', 34, 44 Polymer member 25, 25 ', 35,45,53,53' extreme pressure additive

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuji Igawa 650 Kandamachi, Tsuchiura-shi, Ibaraki Prefecture Within Hitachi Construction Machinery Engineering Co., Ltd.

Claims (5)

[Claims] 1. A pair of annular portions that are spaced apart in the axial direction, a plurality of support portions that are arranged with a gap between the respective annular portions, and that connect the respective annular portions, and rollers that can rotate. In a roller bearing retainer formed as a cylindrical body from a plurality of pockets respectively provided between the pillars for supporting, a recess is formed in the inner wall of the pocket, and the recess is formed in the recess. Is a cage for roller bearings, in which a polymer member impregnated with an extreme pressure additive is embedded. 2. The roller bearing cage according to claim 1, wherein the recessed portion is formed in a plurality of dimples or long grooves provided on the inner wall of the pocket portion. 3. The polymer member embedded in the recess is
A porous polymer material is formed into a porous material, and the extreme pressure additive is impregnated into the porous foamed pores.
Or the cage for roller bearings according to 2. 4. A pair of annular portions that are spaced apart in the axial direction, a plurality of support portions that are arranged with a gap between the respective annular portions, and that connect the respective annular portions, and rollers are rotatable. A roller bearing retainer formed as a cylindrical body from a plurality of pockets respectively provided between the supporting columns for supporting, wherein the pair of annular portions, the supporting columns, and the pockets have extreme pressure. A roller bearing cage characterized by being integrally formed as a cylindrical body from a polymer material impregnated with an additive. 5. A pair of annular portions that are spaced apart in the axial direction, a plurality of pillar portions that are arranged with a gap between the annular portions, and that connect the annular portions, and a roller that is rotatable. A roller bearing retainer formed as a cylindrical body from a plurality of pockets provided between the respective strut portions for supporting, wherein the pair of annular portions, each strut portion, and each pocket portion are foamed. A roller bearing cage characterized in that a polymeric material is integrally foam-molded into a porous body, and an extreme pressure additive is impregnated into the porous foamed pores.