JP2001208086A - Roller follower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller follower wherein a synthetic resin is used for seal materials, thereby not only a development of degradation by radiation of ultraviolet rays is prevented, but also a torque fluctuation becomes low and a grease leakage is lowered. SOLUTION: In the roller follower wherein a plurality of rolling elements 13 are interposed between a outer ring 11 with an outer periphery being made a cam-driven surface and an inner ring 12 or a shaft, a pair of collars 15 are aced in axial direction against stepped flanges 14 of larger diameter on both end of the outer ring 11 and seals 16 for hermeticity of the annular space are arranged on the collars 15, the degradation by radiation of ultraviolet of the seal 16 is suppressed and the sealing effect of low grease leakage is attained by the use of thermoplastic synthetic resin for the seal 16 and by shaping the surface of outer diameter which slidably contacts with the outer ring 11 as a circular section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller follower or cam follower for bringing the outer peripheral surface of an outer ring into contact with a cam to extract a motion corresponding to the cam shape, and more particularly, to an annular ring between an outer ring and an inner ring or a shaft. The present invention relates to a structure of a resin seal for sealing a space.

[0002]

2. Description of the Related Art The structure of a general roller follower is shown in FIG.
As shown in the figure, the inner ring 2 is incorporated into the outer ring 1 having the outer peripheral surface as a cam driven surface, and the retainer 3 is arranged at a fixed interval between the inner diameter surface of the outer ring 1 and the outer diameter surface of the inner ring 2. The outer ring 1 is rotatably held with respect to the inner ring 2 with a plurality of rolling elements 4 interposed, and is fitted and fixed to the end of the inner ring 2 inside the large-diameter step portions 5 provided on both sides of the outer ring 1. The pair of flanges 6 are arranged so as to face each other in the axial direction.

[0003] The cam follower is a roller follower using a shaft as an inner member instead of the inner ring 2.

[0004] Grease as a lubricant is injected into an annular space formed between the inner ring 2 and the outer ring 1. Therefore, a flange is provided on the inner periphery of the large-diameter step portion 5 provided on both sides of the outer ring 1. 6,
A seal 7 is provided for slidingly contacting the outer peripheral surface of 6 to seal grease.

Conventionally, the seal 7 in the roller follower described above is formed by using synthetic rubber such as NBR or ACM (acrylic rubber), and is press-fitted into an annular groove 8 provided on the inner periphery of the large-diameter step portion 5. And a lip portion formed on the inner periphery of the seal 7 is slidably contacted with the outer peripheral surface of the flange 6.

[0006]

However, the rubber seal 7 described above deteriorates in a short period of time when used in an atmosphere where ultraviolet rays are irradiated, and impairs the function as a seal. There is fear.

Accordingly, an object of the present invention is to use a synthetic resin as a sealing material, not only to suppress the occurrence of deterioration due to irradiation with ultraviolet rays, but also to devise the selection of the sealing material, the shape and the fixing structure, so that the torque fluctuation is improved. And to provide a roller follower with small grease leakage.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a plurality of rolling elements are interposed between an outer ring having an outer peripheral surface as a cam driven surface and an inner ring or a shaft.
In a roller follower in which a pair of flanges are axially opposed to the large-diameter step portions on both sides of the outer ring and a seal for sealing the annular space is formed on the flange, the seal is made of a thermoplastic synthetic resin, and the outer ring and This adopts a configuration in which the outer diameter of the sliding contact is formed in an arc-shaped cross section.

According to a second aspect of the present invention, in the first aspect of the present invention, the outer diameter of the seal is formed of a two-peaked arc surface, and a lubricant is interposed in a central concave portion thereof. .

[0010] In a third aspect of the present invention, in the second aspect of the present invention, a slit extending in the axial direction is formed on the arcuate surface of the two ridges so that the inside and outside of the bearing communicate with each other.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the phase of the slit is shifted.

According to a fifth aspect of the present invention, in the first to fourth aspects, the seal is attached to the flange by elastic deformation.

According to a sixth aspect of the present invention, in the invention of the fifth aspect, a projection is provided on the inner diameter of the seal, and the seal is engaged with an annular groove formed on the outer diameter of the flange.

According to a seventh aspect of the present invention, in the first to fourth aspects of the present invention, the flange is formed of a resin seal integrally formed with a cored bar.

According to an eighth aspect of the present invention, in the first to sixth aspects, a resin washer is interposed between the stepped wall surface of the outer ring and the side surface of the flange.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

The roller follower of the example shown in FIG.
An inner ring 12 is incorporated as an inner member inside an outer ring 11 having an outer peripheral surface as a cam driven surface, and an inner diameter surface of the outer ring
A plurality of rolling elements 13 are interposed between the outer ring 11 and the outer ring 11 to hold the outer ring 11 rotatably with respect to the inner ring 12, and inside a large-diameter step portion 14 provided on both sides of the outer ring 11. A pair of flanges 15 fitted and fixed to the end of the inner ring 12 are arranged to face each other in the axial direction.

As another example of the roller follower, although not shown, a shaft is used instead of the inner ring 12 and the outer ring 11 is used.
One flange is formed integrally with the tip of this shaft to be inserted into,
A cam follower structure in which the other flange is fitted in the middle of the shaft may be adopted.

Grease as a lubricant is injected into an annular space formed between the inner ring 12 and the outer ring 11, and a seal 1 is formed on an outer peripheral surface of a flange 15 to seal the grease.
The outer peripheral surface of the seal 16 is in sliding contact with the inner peripheral surface of the large-diameter step portion 14 provided on both sides of the outer ring 11.

The flange 15 is made of metal and is formed on an annular side plate, and has an outer diameter that forms a gap between the inner peripheral surface of the large-diameter step portion 14 and the seal 16. The seal 16 mounted on the outer periphery is formed using a thermoplastic synthetic resin.

The roller follower of the example shown in FIG.
A resin washer 17 is interposed between the wall surface of the large-diameter step portion 14 of the outer ring 11 and the side surface of the flange 15 so as to reduce the generation of resistance due to friction.

As the thermoplastic synthetic resin used for the material of the seal 16, a resin material filled with a sliding material may be selected so as not to increase the friction coefficient (μ). , PPS, PBT,
A thermoplastic synthetic resin such as PA can be exemplified.

The sectional shape of the seal 16 is the large-diameter step portion 1.
4 has a shape that reduces the friction torque while maintaining the sealing effect against the sliding contact with the inner peripheral surface of FIG.
In the example shown in (1), the outer diameter of the seal 16 is a single arcuate surface 18 that bulges outward, thereby reducing the sliding contact resistance with the inner peripheral surface of the large-diameter step portion 14.

The example shown in FIG. 1 and FIG.
2 has an advantage that the outer diameter of the arcuate surface is composed of two arcuate surfaces 19, 19, and that the sliding contact between the two places on both sides has less leakage than the arcuate surface 18 with one seal.
As shown in (C), the lubricant A can always be interposed in the central recess 20 between the two arcuate surfaces 19, and lubrication of the sliding contact portion with the inner peripheral surface of the large-diameter step portion 14 can be achieved. Performance can be improved.

In the example shown in FIG. 4, the outer diameter of the seal 16 is formed by two ridged arc surfaces 19, 19, and a slit extending in the axial direction is formed on the two ridged arc surfaces 19, 19 in order to release the internal pressure of the bearing. 21 are formed in a plurality at regular intervals in the circumferential direction,
The slit 21 allows the inside and outside of the bearing to communicate with each other.
May be arranged in the axial direction, but as shown in the figure, the phase may be shifted in the circumferential direction. If the phase is shifted, there is an advantage that water can be prevented from entering. is there.

FIGS. 3A to 3D show different examples of the method of connecting the seal 16 to the outer diameter of the flange 15. FIG.

The example of FIG. 3A shows a resin seal in which a seal 16 is integrally formed with a core metal 22 having an L-shaped cross section. The core metal 22 itself serves as a flange 15 and is pressed into the inner ring 12 and the shaft. It is intended to be fixed by this.

In the example shown in FIG. 3B, a ridge 23 is provided on the inner diameter of the seal 16, an annular groove 24 for engaging the ridge 23 on the outer diameter of the flange 15, and the seal 16 is In the case where the seal 16 is connected to the outer diameter, the seal 16 is expanded by heating to expand the diameter. In this expanded state, the seal 16 is inserted outside the flange 15, and the seal 16 contracts by returning to normal temperature.
The seal 16 is connected to the outer diameter of the flange 15 without any gap.

FIG. 3C shows the ridge 23 of the seal 16.
The inner diameter surfaces on both sides sandwiching the taper surface 25 are left and right asymmetric taper surfaces 25, and the outer diameter surfaces on both sides sandwiching the annular groove 24 of the flange 15 also correspond to the inner diameter surface of the seal 16.
6, when the seal 16 is coupled to the outer diameter of the flange 15, the seal 16 is elastically deformed so as to expand the diameter.
It is designed to be attached to 5, as in this example,
By providing the tapered surfaces 25 and 26, when the seal 16 is inserted into the outer diameter of the flange 15,
26 guides the expansion of the seal 16, whereby the seal 16 can be attached to the outer diameter of the flange 15 with, for example, an elasticity of 40% or less of the elastic characteristic of the resin.

In the example shown in FIG. 3D, a gap H is formed between the inner diameter surface of the seal 16 and the outer diameter surface of the flange 15 in a state where the seal 16 is mounted on the outer diameter of the flange 15. Fifteen
Is free in the rotation direction to reduce the torque. The method of mounting the seal 16 on the outer diameter of the flange 15 is as described in the example of FIG. Or a method of attaching using elastic deformation.

The roller follower of the present invention has the above-described structure, and has a seal 16 formed of a thermoplastic synthetic resin.
Is in sliding contact with the outer ring 11 so that the outer ring 11 and the inner ring 12
Can be sealed, and the grease in the annular space can be sealed. Even when the roller follower is used in an atmosphere where ultraviolet rays are irradiated, deterioration of the seal 16 can be suppressed. And the durability can be improved.

If the outer diameter of the seal 16 which is in sliding contact with the outer ring 11 has an arc-shaped cross section, and a resin material filled with a sliding material is selected, a sealing effect with less grease leakage can be obtained and a frictional resistance can be reduced. The generation can be reduced and the increase in torque can be suppressed.

[0033]

As described above, according to the present invention, ultraviolet rays are radiated by forming a seal for sealing the annular space between the outer ring and the inner ring with the outer peripheral surface being the cam driven surface by the thermoplastic synthetic resin. Even when used under such conditions, the deterioration of the seal can be suppressed, the durability of the roller follower or the cam follower can be greatly improved, and the outer diameter that is in sliding contact with the outer ring has a circular cross section. With the arc shape, the contact area with the outer ring can be reduced, the occurrence of sliding contact resistance can be reduced, and an increase in torque can be suppressed.

[Brief description of the drawings]

1A is a longitudinal sectional view showing a roller follower of the present invention, FIG. 1B is a front view showing a structure of a flange and a seal, and FIG.
Is an enlarged vertical section showing the structure of the collar and seal

FIG. 2 shows an example in which the cross-sectional shape of the seal is different, and FIG.
Is a cross-sectional view of a seal having a single-peaked arc surface, (B) is a cross-sectional view of a seal having a double-peaked arc surface, and (C) is a cross-sectional view of a seal having a double-peaked arc surface in a state where lubricant is held. Figure

3A and 3B show different examples of a mounting structure of a seal to a flange, and FIG.
(B) is a cross-sectional view of an example of attaching a seal to a flange using expansion by heating, (C) is a cross-sectional view of an example of attaching a seal to a flange using a taper, and (D) is a section between the seal and the flange. Sectional view of an example of mounting with a gap

FIG. 4 is a perspective view of a seal in which a slit is provided on an arc surface of two peaks.

FIG. 5 is a longitudinal sectional view showing a conventional roller follower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Outer ring 12 Inner ring 13 Rolling element 14 Large diameter step part 15 Flange 16 Seal 17 Resin washer 18 Arc surface 19 Arc surface 20 Depression 21 Slit 22 Core metal 23 Protrusion 24 Annular groove 25 Tapered surface 26 Tapered surface

Claims (8)

[Claims] A plurality of rolling elements are interposed between an outer ring having an outer peripheral surface as a cam driven surface and an inner ring or a shaft, and a pair of flanges are axially opposed to large diameter steps on both sides of the outer ring. A roller follower in which a seal for sealing the annular space is formed on the flange, wherein the seal is made of a thermoplastic synthetic resin, and an outer diameter in sliding contact with an outer ring is formed in an arc-shaped cross section. 2. The roller follower according to claim 1, wherein the outer diameter of the seal is a two-sided arcuate surface, and a lubricant is interposed in a central concave portion. 3. The roller follower according to claim 2, wherein a slit extending in the axial direction is formed in the arcuate surface of the two peaks, and the inside and the outside of the bearing communicate with each other. 4. The roller follower according to claim 3, wherein a phase of said slit is shifted. 5. The roller follower according to claim 1, wherein the seal is attached to the flange by elastic deformation. 6. The roller follower according to claim 5, wherein a ridge is provided on an inner diameter of the seal, and is engaged with an annular groove formed on an outer diameter of the flange. 7. The roller follower according to claim 1, wherein the flange is made of a resin seal integrally formed with a cored bar. 8. A resin washer is interposed between a stepped wall surface of the outer ring and a side surface of the flange.
7. A roller follower according to any one of claims 1 to 6.