JP2000145791A - Needle roller bearings and cam followers - Google Patents

Abstract

(57) [Problem] To provide a needle roller bearing capable of supplying a sufficient amount of lubricating oil, enabling maintenance-free operation, and having a low torque and a small temperature rise. SOLUTION: A stud 1 provided with a bearing surface 7a,
An outer ring 3 rotatably fitted to the bearing surface 7a via a needle roller 4, and a stud 1 fitted on one side of the outer ring 3 in the axial direction to restrict the axial movement of the outer ring 3. And a side plate 2 for preventing the needle rollers 4 from coming off.
At 00, a separator 101 made of a molded article of a lubricant-containing polymer is disposed between needle rollers 4 adjacent to each other in a circumferential direction.
Characterized by intervening.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a needle roller bearing and a cam follower.

[0002]

2. Description of the Related Art A cam follower will be described as an example of a conventional needle roller bearing. As shown in FIG. 15, the cam follower includes a stud 1, a side plate 2, an outer ring 3, a needle roller 4, and a cage. 5 is provided. The stud 1 has a flange-shaped head portion 6, a large-diameter shaft portion 7, a medium-diameter shaft portion 8, a small-diameter shaft portion 9, and a screw shaft portion 10 formed in order from one end to the other end. The outer peripheral surface of the radial shaft portion 7 is a bearing outer diameter surface 7a.

An outer ring 3 is rotatably fitted to the bearing outer diameter surface 7a via a needle roller 4, and the needle rollers 4 are held at regular intervals in a circumferential direction by a retainer 5. The annular side plate 2 having the same diameter as the head portion 6 is fitted and fixed to the outer peripheral surface of the middle diameter shaft portion 8. Steps 12 are provided at both ends of the inner diameter of the outer ring 3.
The head portion 6 and the side plate 2 are inserted into the step portions 12 and 13 via a labyrinth 14 having a predetermined gap.

A central greasing hole 15 is provided in the axis of the stud 1, and a branch greasing hole 16 is formed from the center greasing hole 15.
Are provided on the outer peripheral surface of the bearing surface 7a and the small-diameter shaft portion 9, respectively. Grease nipples and plugs (both not shown) are attached to both ends of the center greasing hole 15, and grease supplied from the grease nipple passes through the center greasing hole 15 and the branch greasing hole 16 to the outer ring. 3 to be filled.

[0005] The conventional cam follower is a needle roller 4.
Is held by the cage 5, but a full-roller type cam follower that does not use the cage is conventionally known. In the above-mentioned conventional cam followers, the grease filled as a lubricant in the inner space of the bearing is semi-solid, so that water or the like enters and grease flows out, or dust easily enters the grease. As a result, the cam follower may be insufficiently lubricated and may be seized.

Further, in order to prevent this seizure, maintenance for supplying new grease from the grease nipple is required, and furthermore, it is conceivable that old grease is discharged outside by this grease replenishment, thereby contaminating the surrounding environment. . In order to eliminate various disadvantages caused by the fact that the lubricant is semi-solid grease, Japanese Utility Model Laid-Open Publication No. Hei 6-32809 discloses an ultra-high molecular weight polyolefin instead of grease in the internal space. A cam follower which is made maintenance-free by filling a solid plastic grease consisting of oil and lubricating grease is disclosed. Also, JP-A-10-267031, Utility Model Registration Publication No. 2581636 and Utility Model Registration Publication No. 2
No. 822508 discloses a conventional needle roller bearing in which the internal space (space excluding the needle rollers and the retainer) is filled with the same solid plastic grease.

[0007]

However, cam followers and needle roller bearings in which the solid space is filled with solid plastic grease instead of grease as described above have the following problems. Since the distance between the bearing outer diameter surface (inner ring, shaft, stud, etc.) and the inner ring surface of the outer ring is small, the space for filling plastic grease excluding the needle rollers and the cage becomes even smaller, and as a result, the space is filled. As the absolute amount of lubricant becomes small, it is not possible to expect a life improvement that enables maintenance-free operation. In addition, since the space filled with the plastic grease is small, there are many thin portions of the plastic grease, and therefore, there is a high possibility that the thin portion is damaged due to rotation, and debris generated by the damage is a needle. By inhibiting the movement of the roller and increasing the temperature of the needle roller bearing itself, it is conceivable that the plastic grease softens and causes a further increase in temperature to cause breakage. Since the interior space is completely filled with plastic grease, the movement of the needle rollers during rotation is hindered, resulting in an increase in torque. In the case of cam followers, there are side plates and protruding studs.
It is difficult to fill and fire plastic grease without gaps.

The present invention has been made in view of such a problem, and it is possible to supply a sufficient amount of lubricating oil to enable maintenance-free operation, and to reduce the temperature rise at a low torque. An object is to provide a small number of needle roller bearings and cam followers.

[0009]

In order to achieve the above object, a needle roller bearing according to claim 1 is provided with a bearing outer diameter surface,
In a needle roller bearing including an outer ring fitted to the bearing outer diameter surface via a needle roller, a separator made of a lubricant-containing polymer is interposed between the needle rollers adjacent to each other in a circumferential direction. It is characterized by having.

According to a second aspect of the present invention, there is provided a cam follower having a stud provided with a bearing outer diameter surface, an outer ring rotatably fitted to the bearing outer diameter surface of the stud via a rolling element, and a shaft of the outer ring. A side plate that is fitted to the stud on one side in the direction, and that restricts the axial movement of the outer ring and that prevents the rolling element from falling off, between the rolling elements adjacent to each other in the circumferential direction. And a separator made of a lubricant-containing polymer.

Here, the material of the lubricant-containing polymer of the present invention is obtained by lubricating a synthetic resin selected from the group of polyolefin resins having basically the same chemical structure, such as polyethylene, polypropylene, polybutylene, and polymethylpentene. Any of paraffinic hydrocarbon oils such as poly-α-olefin oils, naphthenic hydrocarbon oils, mineral oils, liquid paraffins, ether oils such as dialkyldiphenyl ether oils, ester oils such as phthalic acid esters, etc. Alternatively, the raw material mixed and adjusted in the form of a mixed oil is plasticized by heating it above the melting point of the resin and then solidified by cooling.The antioxidant and rust inhibitor in the lubricant beforehand And various additives such as an anti-wear agent, a defoaming agent, and an extreme pressure agent.

The composition ratio of the lubricant-containing polymer is 20 to 70% by weight of the polyolefin resin and 80 to 30% by weight of the lubricant based on the total weight. 2 polyolefin resin
If the content is less than 0% by weight, a certain level of hardness and strength cannot be obtained, and it becomes difficult to maintain the initial shape when a load is applied due to rotation of the bearing, and there are problems such as breakage inside the bearing. Is more likely to occur.

The polyolefin resin is 70% by weight.
(That is, when the lubricant is less than 30% by weight).
), The amount of lubricant supplied to the bearing decreases,
The basic structure of the above synthetic resin group, which shortens the life, is the same
Have different average molecular weights, 700 to 5 × 10⁶
Range. Average molecular weight 700-1 × 10^FourWhen
(Eg, polyethylene wax)
And an average molecular weight of 1 × 10 ^Four~ 1 × 10⁶That
Relatively low molecular weight, average molecular weight 1 × 10⁶~ 5x
10⁶Of ultra high molecular weight
Mix and use according to. Lubricant with relatively low molecular weight
Some mechanical strength and lubrication depending on the combination with the agent
Lubricant-containing polymer with agent supply capacity and oil retention
You.

Some of those having a relatively low molecular weight are
When replaced with wax, the difference in molecular weight between the wax and the lubricating oil is small, so that the affinity with the lubricating oil is increased, and as a result, the oil retaining property of the lubricant-containing polymer is improved. Thus, the lubricant can be supplied for a long period of time. However, on the other hand, the mechanical strength decreases.

As the wax, besides a polyolefin resin such as polyethylene wax, a melting point of 100 to 1 is used.
Any hydrocarbon-based material (for example, paraffin-based synthetic wax) in the range of 30 ° C. or more can be used. On the other hand, if it is replaced with ultra-high molecular weight one, the difference in molecular weight between the ultra-high molecular weight one and the lubricating oil will be large, and the affinity with the lubricating oil will be low. The bleeding of the lubricant from the contained polymer is accelerated. This shortens the time to reach the amount of lubricant that can be supplied from the lubricant-containing polymer, and shortens the bearing life. However,
The mechanical strength is improved.

Considering the balance of moldability, mechanical strength, oil retention and lubricant supply, the composition ratio of the lubricant-containing polymer is 0 to 5% by weight classified as wax and relatively low molecular weight. 8 to 50% by weight, ultra high molecular weight 2
It is preferable that the total amount of the three resin components is 15 to 70% by weight (the remaining amount is 80 to 30% by weight of the lubricant). As one of the mechanical strengths, the hardness [HD _A ] of the lubricant-containing polymer is preferably 65 or more, more preferably 70 or more. If [HD _A ] is less than 65, the strength becomes weak, and the bearing may be damaged by rotation.

Further, in order to improve the mechanical strength of the lubricant-containing polymer, a thermoplastic resin and a thermosetting resin as described below may be added to the above-mentioned polyolefin resin. As the thermoplastic resin, polyamide, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, polyether sulfone, polyether ether ketone, polyamide imide, polystyrene, A
Each resin such as a BS resin can be used.

As the thermosetting resin, resins such as unsaturated polyester resin, urea resin, melanin resin, phenol resin, polyimide resin and epoxy resin can be used. These resins may be used alone or as a mixture. Further, in order to disperse the polyolefin resin and the other resin in a more uniform state, a suitable compatibilizer may be added as needed.

Further, a filler may be added to improve the mechanical strength. For example, calcium carbonate, magnesium carbonate, inorganic whiskers such as potassium titanate whiskers and aluminum borate whiskers, or inorganic fibers such as glass fibers and metal fibers and those obtained by braiding them in a cloth form, and in the case of organic compounds, Carbon black, graphite powder, carbon fiber, aramid fiber, polyester fiber and the like may be added. Further, in order to improve self-lubricating properties, molybdenum disulfide, boron nitride (h-B
A solid lubricant such as N) may be contained.

Further, in order to prevent deterioration of the polyolefin resin due to heat, N, N'-diphenyl-P-phenyldiamine, 2,2'-methylenebis (4-ethyl-
Antioxidants such as 6-t-butylphenol), and 2-hydroxy-4-n-
Octoxybenzophenone, 2- (2'-hydroxy-
An ultraviolet absorber such as 3'-t-butyl-5'-methyl-phenyl) -5-chlorobenzotriazole may be added.

The additive amount of all of the above additives (other than the polyolefin resin and the lubricant) should be 20% by weight or less of the total amount of the molding raw material as a whole of the additives so as to maintain the lubricant supply capacity. Preferred above. As the polymer material that can be used in the present invention, in addition to those based on the polyolefin resin described above, steel equipment such as continuous casting, engine accessories such as superchargers and superchargers, and the like. Needle bearings used include:
Further, heat resistance is required, and specifically, a polyester-based elastomer or the like, which is a thermoplastic resin that can be injection-molded, is preferable because the oil content can be increased. Similarly, thermosetting resins such as polyurethane and polyurea elastomers can be used for heat-resistant applications.

In the case of polyurethane, a grease is used as a lubricant, a urethane prepolymer containing an isocyanate group, which is a reaction raw material, and an amine-based curing agent are uniformly mixed with the grease, and then the two mixtures are further mixed. Then, the mixture is filled in a mold having a desired shape, heated and reacted as needed, and cured with grease contained.

In the case of a polyurea elastomer, an amine component comprising a mixture of an aromatic polyamine compound containing a soft segment in the molecular chain and an aromatic diamine is used as a lubricant compatible with the amine component or a grease using the lubricant as a base oil. The polyisocyanate component is further added to the uniformly mixed mixture, and the mixture is mixed and filled into a mold having a desired shape, and if necessary, heated and reacted to be cured in a state in which the lubricant is contained. .

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory sectional view for explaining a cam follower according to a first embodiment of the present invention.
3 is an overall perspective view of a separator, FIG. 3 is an explanatory sectional view for explaining a cam follower according to a second embodiment of the present invention, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, and FIG. FIG. 6 is an explanatory sectional view for explaining a cam follower according to a third embodiment of the present invention, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, and FIG.
Is an explanatory sectional view for explaining a roller follower according to a fourth embodiment of the present invention, FIG. 8 is an overall perspective view of a separator, and FIG. 9 is a solid needle according to a fifth embodiment of the present invention. Explanatory sectional view for explaining a roller bearing, FIG.
FIG. 3 is an overall perspective view of a separator. The basic structure of the cam follower according to each of the first to third embodiments is shown in FIG.
Is the same as that of the conventional cam follower shown in FIG. 2 except that the greasing holes 15 and 17 and the retainer 5 are not provided.

A cam follower 100 shown in FIG. 1 is a separator made of a molded article of a lubricant-containing polymer having substantially the same shape as that of a conventional cage, between needle rollers 4 adjacent to each other in the circumferential direction. 101 is interposed.
The separator 101 is in non-contact with the outer race 3 and the bearing outer diameter surface 7a of the stud 1, and as shown in FIG. 2, is formed in a cylindrical shape and has a rectangular hole 102 in which a needle roller 4 is accommodated in its peripheral wall. Are formed at equal intervals in the circumferential direction corresponding to the number of the needle rollers 4. The thickness of the separator 101 is thicker than that of the conventional cage, slightly smaller than the diameter of the needle roller 4, and the outer diameter is slightly smaller than the inner diameter surface of the outer ring 3, and the inner diameter is the outer diameter surface of the bearing. The diameter is slightly larger than 7a.

Specifically, the thickness of the separator 101 is
When the diameter of the needle rollers 4 is 100%, 70 to 85%
Is suitable. If less than 70%, the separator 10
It becomes difficult to contain a sufficient amount of lubricant in 1,
On the other hand, if it exceeds 85%, the gap between the bearing 101 and the separator 101 and the inner surface of the outer ring and the separator 101 cannot be provided to some extent or more.

The gap between the bearing outer diameter surface 7a and the outer ring inner diameter surface and the separator 101 is such that the diameter of the needle roller 4 is 1
If it is 00%, the range of 7.5 to 20% is preferable.
If it is less than 7.5%, the gap between the bearing outer diameter surface 7a and the outer ring inner diameter surface and the separator 101 cannot be provided to some extent or more.
It becomes difficult to make 1 contain a sufficient amount of lubricant.

The rectangular hole 102 is formed to be slightly larger than the needle roller 4 so as to prevent the stored needle roller 4 from being restrained.
It is only necessary that a pocket gap be secured. Due to the above dimensional relationship, the movement of the needle rollers 4 is not restricted and the separator 10
Since the surface 1 is not in contact with the outer ring 3 and the stud 1, and the surface is wet with the lubricant, a bearing having a low friction coefficient and a very low torque can be obtained.

The lubricant-containing polymer constituting the separator 101 is different from a normal oil-containing plastic in which oil is independently dispersed and solidified from a state in which the lubricant and the polymer are microscopically compatible. Communicates with the interior. Since the lubricant and the polymer are in a mutually compatible combination, the speed at which phase separation occurs is slow,
As a result, the lubricant released to the outside is also gradually supplied. Further, since the lubricant exists in the continuous phase, the lubricant is constantly replenished from the inside, and the lubricant can be stably supplied for a long period of time.

As described above, in this embodiment, between the needle rollers 4 adjacent to each other in the circumferential direction, a molded product of the lubricant-containing polymer that gradually supplies a sufficient volume of lubricant to the internal space of the bearing. Since the separator 101 is interposed, the lubricant can be stably supplied to the internal space of the bearing for a long period of time, and a good lubrication state can be maintained. As a result, maintenance-free operation is possible. Can be

In addition, since a sufficient thickness of the separator 101 can be ensured in terms of strength, as in the conventional case, fragments generated due to breakage hinder the movement of the needle rollers and raise the temperature of the cam follower itself. Can be eliminated. Further, the separator 101 is molded in advance as a separate body, and when the base resin is a thermoplastic resin, injection molding is also possible, so that the internal space is filled with solid plastic grease as compared with the conventional one. It can be manufactured stably at low cost.

Next, referring to FIGS. 3 to 6, cam followers 200 and 3 according to second and third embodiments of the present invention.
00 will be described. Since the operation and effect are the same as those of the above-described cam follower 100, the description thereof will be omitted. First, a cam follower 200 according to a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. This cam follower 200 has a conventional retainer removed.
A separator 201 made of a molded article of a lubricant-containing polymer having substantially the same shape as the needle rollers 4 is interposed between the needle rollers 4 adjacent to each other in the circumferential direction.

The separator 201 is, as shown in FIG.
It is formed in a substantially columnar shape and is in non-contact with the outer diameter surface 7a of the outer ring 3 and the bearing 1 of the stud 1, and its diameter is slightly smaller than the diameter of the needle roller 4, so that it is not directly loaded. I have. Specifically, when the diameter of the needle rollers 4 is 100%, the diameter of the separator 201 is preferably in the range of 80 to 95%. If less than 80%, the separator 201
It is difficult to contain a sufficient amount of the lubricant, while if it exceeds 95%, the possibility of receiving a load is undesirably increased. The length of the separator 201 is substantially the same as that of the needle roller 4.

In a cam follower 300 according to a third embodiment of the present invention, a conventional retainer is removed, and FIGS.
As shown in FIG. 5, a columnar separator 301 made of a molded body of a lubricant-containing polymer is interposed between needle rollers 4 adjacent to each other in the circumferential direction. Separator 301
As shown in FIG. 6, the outer diameter of the outer ring 3 and the bearing outer diameter surface 7 of the stud 1 is slightly thinner than the diameter of the needle roller 4.
a is not in contact with both sides in the width direction (the needle rollers 4).
A curved concave portion 302 corresponding to the outer peripheral surface of the needle roller 4 is formed on the side portion sandwiched between the rollers.

Next, a roller follower 400 according to a fourth embodiment of the present invention will be described with reference to FIGS.
A solid needle roller bearing 500 according to a fifth embodiment of the present invention will be described with reference to FIG. Since the operation and effect are the same as those of the above-described cam follower 100, the description thereof will be omitted. First, the fourth of the present invention
The roller follower 400 according to the embodiment of the present invention will be described. As shown in FIG.
Inner ring 411, side plate 412, outer ring 413, needle roller 414
And a sealing material 416 between the needle rollers 414 adjacent to each other in the circumferential direction inside the bearing.
15 (see FIG. 11), in which a separator 401 made of a molded article of a lubricant-containing polymer is interposed.

The outer peripheral surface at the center in the axial direction of the inner ring 411 is a bearing outer diameter surface 407a, and both ends are formed on the bearing outer peripheral surface 40a.
The diameter is smaller than 7a. Side plates 412 are forcibly fitted to both ends of the inner ring 411, respectively.
An outer ring 413 is rotatably fitted to 7a via a needle roller 414. The needle rollers 414 are connected to the separator 40.
1 is held at a constant interval in the circumferential direction. Outer ring 4
Steps 422 and 423 are provided at both ends of the inner diameter of the thirteen, and a side plate 412 is inserted into each of the steps 422 and 423 via a sealant 416. Note that the inner ring 411 is not provided with a greasing hole 425 like the conventional roller follower shown in FIG.

The separator 401 includes the outer ring 413 and the inner ring 4
8 is in non-contact with the bearing outer diameter surface 407a of FIG.
As shown in the figure, a rectangular hole 402 formed in a cylindrical shape and accommodating a needle roller 414 in a peripheral wall portion thereof is formed in the needle roller 41.
Four are formed at equal intervals in the circumferential direction corresponding to the number of the four. The thickness of the separator 401 is slightly smaller than the diameter of the needle rollers 414, and the outer diameter is slightly smaller than the inner diameter surface of the outer ring 413, and the inner diameter is slightly larger than the bearing outer diameter surface 407a. I have.

Specifically, the thickness of the separator 401 is
When the diameter of the needle rollers 414 is 100%, 70 to 8
A range of 5% is preferred. If it is less than 70%, it becomes difficult to make the separator 401 contain a sufficient amount of lubricant. On the other hand, if it exceeds 85%, a gap between the bearing 401 and the inner surface of the outer ring and the separator 401 must be provided to a certain degree or more. Can not be done.

The gap between the bearing outer diameter surface 407a and the outer ring inner diameter surface and the separator 401 is preferably in the range of 7.5 to 20% when the diameter of the needle rollers 414 is 100%. If it is less than 7.5%, a gap between the bearing outer diameter surface 407a and the outer ring inner diameter surface and the separator 401 cannot be provided to some extent or more, while if it exceeds 20%, the separator 401 contains a sufficient amount of lubricant. It becomes difficult to make it.

The rectangular hole 402 is formed to be slightly larger than the needle roller 414 so that the accommodated needle roller 414 is not restrained.
What is necessary is to secure a pocket gap of 0.2 mm. next,
A solid needle roller bearing 500 according to a fifth embodiment of the present invention will be described.
9, an inner ring 511, an outer ring 513 and a needle roller 514 are provided, and a conventional retainer 51 is provided between needle rollers 514 adjacent to each other in the circumferential direction inside the bearing.
5 (see FIG. 12), in which a separator 501 made of a molded article of a lubricant-containing polymer is interposed.

The outer peripheral surface of the inner ring 511 is a bearing outer diameter surface 507a.
An outer ring 513 having flanges at both ends is rotatably fitted to the bearing outer diameter surface 507a via needle rollers 514. The needle rollers 514 are held at regular intervals in the circumferential direction by the separator 501. The outer ring 51
3 is not provided with a greasing hole 525 as in the conventional solid needle roller bearing shown in FIG.

The separator 501 includes the outer ring 513 and the inner ring 5
11 is in non-contact with the bearing outer diameter surface 507a.
As shown in FIG. 0, a small-diameter portion 501a corresponding to the flange portion 513a of the outer ring 513 is formed at both ends in the axial direction in a substantially cylindrical shape. Rectangular holes 502 for accommodating the needle rollers 514 are formed at equal intervals in the circumferential direction on the peripheral wall of the center part of the separator 501 in the axial direction, the number corresponding to the number of the needle rollers 514. The thickness of the central portion of the separator 501 in the axial direction is slightly smaller than the diameter of the needle roller 514, the outer diameter is slightly smaller than the inner diameter surface of the outer ring 513, and the inner diameter is slightly smaller than the bearing outer diameter surface 507a. It has a large diameter.

Specifically, the thickness of the central portion of the separator 501 in the axial direction is preferably in the range of 70 to 85% when the diameter of the needle rollers 514 is 100%. If it is less than 70%, it becomes difficult to make the separator 501 contain a sufficient amount of lubricant. On the other hand, if it exceeds 85%, it is necessary to provide a gap between the bearing 501 and the inner surface of the outer ring and the separator 501 to some extent or more. Can not be done.

Further, the bearing outer diameter surface 507a and the outer ring 513
The gap between the inner diameter surface of the separator 501 and the central portion in the axial direction of the separator 501, and the gap between the outer diameter surface 507a of the bearing and the flange portion 513a of the outer ring 513 and the small diameter portion 501a of the separator 501 have the needle roller 514 having a diameter of 100%. Then, 7.5
A range of -20% is preferred. If it is less than 7.5%, the above-mentioned gaps cannot be provided to some extent or more, while if it exceeds 20%, it becomes difficult to make the separator 501 contain a sufficient amount of lubricant.

The rectangular hole 502 is formed to be slightly larger than the needle roller 514 so that the accommodated needle roller 514 is not restrained.
What is necessary is to secure a pocket gap of 0.2 mm. In addition,
In each of the above-described embodiments, in addition to the provision of the separator made of the molded body of the lubricant-containing polymer as the lubricant supply means, the remaining space may be filled with grease.

[0046]

EXAMPLES (Example 1: Applied to cam followers) Lubricant-containing polymer composition of separator High-density polyethylene (classified into relatively low molecular weight): 40 w
t% Ultra high molecular weight polyethylene (classified as ultra high molecular weight): 8 wt
% Polyethylene wax (classified as wax): 2 wt% Mineral oil: 50 wt% Structure: FIGS. 1 and 2 Molding method: injection molding Details: The outer diameter of this separator is 0.5 m from the inner diameter of the outer ring
m and the inner diameter is 0.5 mm larger than the outer diameter of the stud. The thickness is 1 mm smaller than the diameter of the needle roller, and the width of the rectangular hole (corner R) is 0.5 mm from the diameter of the needle roller.
large. (Example 2: Applied to cam follower) Lubricant-containing polymer composition of separator High-density polyethylene (classified into relatively low molecular weight): 35 w
t% Ultra high molecular weight polyethylene (classified as ultra high molecular weight): 13w
t% Polyethylene wax (classified as wax): 2 wt% Mineral oil: 50 wt% Structure: FIGS. 3 and 4 Molding method: injection molding Details: This separator is 0.5 mm smaller in diameter than the needle rollers. However, the length is the same. Apparently the same as the full roller type. (Example 3: Applied to cam follower) Polymer composition containing lubricant in separator High-density polyethylene (classified into relatively low molecular weight): 45 w
t% Ultra high molecular weight polyethylene (classified as ultra high molecular weight): 13w
t% Polyethylene wax (classified as wax): 2 wt% Mineral oil: 40 wt% Structure: FIGS. 5 and 6 Molding method: injection molding Details: This separator is 0.5 mm thinner than the needle roller diameter and has a length Is the same as a needle roller. (Example 4: Applied to roller follower) Lubricant-containing polymer composition of separator High-density polyethylene (classified into relatively low molecular weight): 40 w
t% Ultra high molecular weight polyethylene (classified as ultra high molecular weight): 8 wt
% Polyethylene wax (classified as wax): 2 wt% Mineral oil: 50 wt% Structure: FIGS. 7 and 8 Molding method: injection molding Details: The outer diameter of this separator is 0.5 m from the inner diameter of the outer ring
m and the inner diameter is 0.5 mm larger than the outer diameter of the inner ring. The wall thickness is 1 mm smaller than the diameter of the needle rollers, and the width of the rectangular hole (corner R) is 0.5 mm larger than the diameter of the needle rollers. (Example 5: Applicable to solid needle roller bearings) Polymer composition containing lubricant for separator High-density polyethylene (classified into relatively low molecular weight): 40 w
t% Ultra high molecular weight polyethylene (classified as ultra high molecular weight): 8 wt
% Polyethylene wax (classified as wax): 2 wt% Mineral oil: 50 wt% Structure: FIGS. 9 and 10 Molding method: injection molding Details: The outer diameter of this separator is 0.5 m from the inner diameter of the outer ring
m and the inner diameter is 0.5 mm larger than the outer diameter of the inner ring. The wall thickness is 1 mm smaller than the diameter of the needle rollers, and the width of the rectangular hole (corner R) is 0.5 mm larger than the diameter of the needle rollers. (Example 6: Applicable to cam followers) Test size Outer diameter 40 mm x width 20 mm x shaft diameter 20 mm
Experimental conditions: Radial load Fr: 50 kgf, number of revolutions N: 200 rpm Lubrication conditions As a comparative example, as shown in FIG. 13, a conventional cam follower with a retainer was used in which a lubricant-containing polymer was sealed in the bearing internal space. As an embodiment, as shown in FIG. 1, a separator 1 is provided in the internal space of the bearing instead of the retainer.
The dynamic torque ratio of the cam follower of the present invention with the 01 interposed was compared. FIG. 14 shows the results.

As is apparent from FIG. 14, the dynamic torque ratio of the embodiment is much smaller than that of the comparative example.

[0048]

As is clear from the above description, according to the present invention, it is possible to supply a sufficient amount of lubricating oil to enable maintenance-free operation, and at the same time, to obtain a needle-shaped needle having a low torque and a small temperature rise. The effect that a roller bearing and a cam follower can be provided is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view illustrating a cam follower according to a first embodiment of the present invention.

FIG. 2 is an overall perspective view of a separator.

FIG. 3 is an explanatory sectional view for explaining a cam follower according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is an explanatory sectional view for explaining a cam follower according to a third embodiment of the present invention.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is an explanatory cross-sectional view illustrating a roller follower according to a fourth embodiment of the present invention.

FIG. 8 is an overall perspective view of a separator.

FIG. 9 is an explanatory cross-sectional view for explaining a solid needle roller bearing according to a fifth embodiment of the present invention.

FIG. 10 is an overall perspective view of a separator.

FIG. 11 is an explanatory sectional view for explaining a roller follower as an example of a conventional needle roller bearing.

FIG. 12 is an explanatory cross-sectional view illustrating a solid needle roller bearing as an example of a conventional needle roller bearing.

FIG. 13 is a sectional view showing a cam follower as a comparative example.

FIG. 14 is a graph showing a comparison between dynamic torque ratios in a comparative example and an example.

FIG. 15 is an explanatory sectional view for explaining a cam follower as an example of a conventional needle roller bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stud 2 ... Side plate 3 ... Outer ring 4 ... Needle roller 7a ... Bearing outer diameter surface 100 ... Cam follower 101 ... Separator 102 ... Rectangular hole 200 ... Cam follower 201 ... Separator 300 ... Cam follower 301 ... Separator 400 ... Roller follower 401 ... Separator 402 ... Rectangular hole 407a ... Bearing outer diameter surface 411 ... Inner ring 413 ... Outer ring 414 ... Needle roller 500 ... Solid needle roller bearing 501 ... Separator 502 ... Rectangular hole 507a ... Bearing outer diameter surface 511 ... Inner ring 513 ... Outer ring 514 ... Needle Roller

Claims (2)

[Claims] 1. A needle roller bearing having a bearing outer diameter surface and an outer ring fitted to the bearing outer diameter surface via a needle roller, between the needle rollers adjacent to each other in a circumferential direction. A needle roller bearing comprising a separator made of a polymer containing a lubricant interposed therebetween. 2. A stud provided with a bearing outer diameter surface, an outer ring rotatably fitted to the bearing outer diameter surface of the stud via a rolling element, and a stud on one side in the axial direction of the outer ring. A cam follower fitted to a stud and having a side plate that regulates the axial movement of the outer race and prevents the rolling element from falling off, wherein a lubricant-containing polymer is disposed between the rolling elements adjacent to each other in the circumferential direction. A cam follower characterized by having a separator interposed therebetween.