JP2009299819A - Cam follower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cam follower simplified in the shape of a shaft, reduced in manufacturing cost, and having an excellent function coping with a generated thrust load. <P>SOLUTION: This cam follower includes: a shaft 1; a shell-shaped inner ring 2 pressed into a tip of the shaft 1; an outer ring 3 having the outer peripheral surface formed into a driven surface 3; and a roller 4 with a cage interposed between the outer ring 3 and the shell-shaped inner ring 2. The shell-shaped inner ring 2 has flanges 2b extending to the outer diameter at both ends, and the outer ring 3 and the roller 4 with a cage are assembled between both the flanges 2b and 2b. The outer ring 3 is formed into a solid shape by grinding a steel material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cam follower incorporated in a cam mechanism or a slide guide mechanism of a slide member.

  As a conventional cam follower, a standard cam follower shown in FIG. 5 and a structure shown in FIG. 6 (Patent Document 1) are known. The cam follower of FIG. 5 is configured by incorporating a roller 14 with a retainer and a solid outer ring 13 into a shaft 11 having a flange 11a extending to the outer diameter side at one end, and finally press-fitting a side plate 12 into the shaft 11. The The roller 14 with cage and the outer ring 13 are assembled between the flange 11 a of the shaft 11 and the side plate 12. The side plate 12 is fixed in the axial direction by a step 11 b provided on the outer periphery of the shaft 11.

The cam follower (FIG. 6) disclosed in Patent Document 1 is configured by assembling a shell-type roller bearing 20 with an inner ring to one end portion of a shaft 21. The shell-type roller bearing 20 includes a shell-type inner ring 22 with a single flange that is press-fitted into a shaft 21, a shell-type outer ring 23 whose outer peripheral surface is a driven surface, and a cage interposed between the inner and outer rings 22, 23. It becomes with roller 24. The outer peripheral shape of the longitudinal section of the shaft 21 is a straight shape without a step.
JP 2000-320646 A

  In the case of the cam follower having the standard structure shown in FIG. 5, the movement of the outer ring 13 in the axial direction is restricted by the side plate 12 and the flange 11a of the shaft 11, and it is necessary to increase the outer diameter of the flange 11a of the shaft 11 to some extent. is there. For this reason, when the shaft 11 is turned by, for example, turning from a bar material, the amount of turning becomes very large and the machining cost becomes high. Moreover, since it is necessary to provide the roller rolling surface, the level | step difference used as the press-fit part of the side plate 12, etc. in the outer periphery of the axis | shaft 11, the cost of turning and grinding becomes high. Further, since the roller rolling surface of the shaft 11 receives a load from the roller 16, it needs to be heat-treated and hardened. The end of the shaft 11 opposite to the flange forming side is generally machined with a male threaded portion 11c for attachment to the support member. Since this male threaded portion 11c cannot be cured, it rolls in advance at a high frequency. It is necessary to go through a complicated procedure such as heat-treating only the surface portion or subjecting the male screw portion 11c to a carburizing treatment and then performing a heat treatment such as carburizing, which further increases the cost.

In the case of the cam follower disclosed in Patent Document 1 (FIG. 6), the shaft 21 has no flange, the outer peripheral shape of the longitudinal section thereof is a straight shape without a step, and the shell-shaped roller bearing 20 with an inner ring is assembled. The shape of the shaft 21 is simple and no heat treatment is required, so that the cost can be reduced.
However, the response to the induced thrust force is not sufficient. That is, when using the cam follower, an induced thrust load may be generated on the outer ring due to an attachment error between the cam and the outer ring. In the cam follower of Patent Document 1, when an induced thrust load is generated as indicated by an arrow P in FIG. 6, the cage 25 is sandwiched inside the shell roller bearing 20, or the end surface of the cage 25 and the flange surface of the outer ring 23. In addition, wear or the like may occur at the contact portion of the inner ring 22 on the flange surface. This wear is more likely to occur due to the small contact area of the end face of the cage 25.
Furthermore, since the outer ring 23 has a shell shape and is thin, there is a concern about damage or the like when receiving a heavy load or impact load from the cam. In addition, when the shaft 21 is incorporated in the support member 27 as shown in FIG. 7, an appropriate gap is secured between the support member 27 and the outer ring 23 to make contact between the width surface of the support member 27 and the width surface of the outer ring 23. It is necessary to avoid and avoid wear and torque increase. However, since the outer peripheral shape of the shaft 21 is a straight shape, positioning in the axial direction is difficult, and it is difficult to ensure an appropriate gap between the support member 27 and the outer ring 23.

  An object of the present invention is to provide a cam follower capable of simplifying the shaft shape, reducing the manufacturing cost, and excellent in the function to cope with the induced thrust load.

The cam follower according to the present invention includes a shaft whose one end is supported by a support member, a shell-shaped inner ring press-fitted to the other end of the shaft, an outer ring whose outer peripheral surface is a driven surface, the outer ring, A roller with a cage interposed between the inner ring and the shell type inner ring, the shell type inner ring having flanges extending to the outer diameter side at both ends, and the outer ring and the roller with a cage are incorporated between the two flanges. It is characterized by that.
According to this configuration, since the inner ring is fitted with both flanges and is press-fitted and fixed to the shaft as a shell shape, there is no need to provide a flange or a step for fixing the flange on the shaft. Processing costs such as grinding are reduced, and the cost can be reduced. Further, since the inner ring is provided and the outer diameter surface of the shaft does not directly become a roller rolling surface, it is not necessary to be cured by heat treatment, the heat treatment cost can be reduced, and the cost can be further reduced. In addition, since the inner ring has both flanges, and the outer ring and the roller with cage are incorporated between the flanges, the cage is not pinched between the flanges of the inner and outer rings even if induced thrust force acts on the outer ring. . The contact area between the flange of the inner ring and the side surface of the outer ring can be secured to the same level as the conventional standard cam follower, and the above-mentioned conventional shell type inner ring with a single flange is used for wear resistance against induced thrust load. It will be superior to the cam followers.

  In the present invention, the outer ring may be made of a machined steel product, and may have annular recesses in which the flanges of the inner ring are fitted on the inner diameter portions on both side surfaces. When the outer ring is made of steel material, unlike the shell type outer ring, there is no risk of damage even when subjected to heavy load or impact load from the cam. If the outer ring has annular recesses on both sides to fit the inner ring flange, the inner ring flange will not protrude, and the overall width of the cam follower roller will be larger than the required width of the outer ring driven surface. it can.

  In the present invention, the outer peripheral shape of the shaft may be a stepless shape having no step, that is, a so-called straight shape. By adopting the step-less shape, the processing costs such as turning and grinding when forming the shaft can be further reduced.

In the present invention, a step for positioning in the axial direction with respect to a support member supporting the base end portion of the shaft may be provided on the outer periphery of the shaft.
In this configuration, for example, even when the shell type inner ring is fixed to the shaft only by press fitting, when the shaft is fastened to the support member, the axial force by the support member does not act on the shell type inner ring, and the shell type inner ring is not It can be prevented from falling off in the axial direction. In the case of this configuration, it is preferable that the shaft has a stepless shape having no step other than the positioning step.

  In the present invention, the shell-shaped inner ring may be fixed in the axial direction by a caulking portion formed at the other end of the shaft. As a result, the inner ring can be fixed more firmly than the fixing by press-fitting alone. Because it is caulked, it can be fixed easily.

  In this invention, the shell-shaped inner ring may be fixed in the axial direction by a retaining ring fitted to the shaft or by welding. In this case as well, the inner ring can be fixed more firmly than the fixing by press-fitting alone.

  In the present invention, one or both of the flanges at both ends of the shell-shaped inner ring may be configured as separate side plates with respect to the shell-shaped inner ring main body having a rolling surface. When a separate side plate is used, the operation of incorporating the outer ring and the roller with the cage between both flanges of the inner ring is simplified.

In this invention, you may provide the washer which regulates the axial direction movement of the said outer ring | wheel in the inner side of one or both of the both flanges of the said shell type inner ring | wheel.
Thus, when the washer for restricting the axial movement of the outer ring is provided inside the flange, the outward height of the flange can be lowered. Therefore, after the roller with a cage and the outer ring are incorporated into the shell-type inner ring, cracking when the flange is bent can be prevented, and the shell-type inner ring can be easily manufactured.

  The cam follower according to the present invention includes a shaft, a shell-shaped inner ring fitted in a press-fit state at a tip portion of the shaft, an outer ring having an outer peripheral surface as a driven surface, and an intermediate between the outer ring and the shell-shaped inner ring. And the shell-shaped inner ring has flanges extending to the outer diameter side at both ends, and the outer ring and the roller with cage are incorporated between the two flanges, so that the shaft shape can be simplified. In addition, the manufacturing cost can be reduced, and the support function such as avoidance of holding the cage with respect to the induced thrust load and reduction of wear is excellent.

  A first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1A, the cam follower includes a shaft 1, a shell-shaped inner ring 2 press-fitted to the tip of the shaft 1, a solid outer ring 3, the solid outer ring 3, And a roller with a cage 4 interposed between the inner shell 2 and the shell-shaped inner ring 2. The solid outer ring 3 is made of a machined steel material. The shell-shaped inner ring 2 is formed from a steel plate by press working such as deep drawing, has flanges 2b extending to the outer diameter side at both ends, and an outer peripheral surface is a roller rolling surface 2a. The solid outer ring 3 and the roller 4 with cage are incorporated between the flanges 2b, 2b of the shell type inner ring 2. The inner peripheral surface of the solid outer ring 3 is a roller rolling surface 3a, and the outer peripheral surface is a driven surface 3b. An annular recess 3c into which the flanges 2b, 2b of the shell-shaped inner ring 2 are fitted is formed on the inner diameter portions on both side surfaces of the solid outer ring 3. The roller with cage 4 is configured such that rollers 6 are rotatably accommodated in pockets 5a at a plurality of circumferential positions provided in a cylindrical cage 5.

  A male screw portion 1 a is formed at the base end portion of the shaft 1. The male screw portion 1a is inserted into an attachment hole of a support member (not shown) and tightened with a nut, whereby the shaft 1 is supported by the support member at the base end portion. The outer peripheral shape of the shaft 1 is a so-called straight shape, which is a stepless shape formed of a cylindrical surface having no steps except for the male screw portion 1a and an oil hole (not shown).

  As shown in FIG. 1B, the shell-shaped inner ring 2 is pressed in a shape in which one flange 2b of both flanges 2b extends in the axial direction to form a straight portion 2b '. After assembling the roller 4 with a cage and the solid outer ring 3 from the straight portion 2b ′ extending in the axial direction into the shell-shaped inner ring 2 processed in this way, as shown in FIG. By bending the straight portion 2b ′ to the outer diameter side by roll forming or the like, the shell-shaped inner ring 2 having flanges 2b extending to the outer diameter side at both ends is formed. As described above, the shell-shaped inner ring 2 is an assembly in which the roller 4 with cage and the solid outer ring 3 are assembled, and the shell-shaped inner ring 2 is press-fitted to the tip of the shaft 1 in this assembled state. The shell-shaped inner ring 2 is subjected to a heat treatment such as quenching, but the straight portion 2b 'to be bent is an unheat-treated portion (or the hardness is reduced by annealing after quenching).

  After the press fitting of the shell-shaped inner ring 2, the tip end portion of the shaft 1 is crimped to the outer diameter side to form a crimped portion 1b, and the shell-shaped inner ring 2 is fixed in the axial direction by the crimped portion 1b. The axial fixing for preventing the shell-shaped inner ring 2 from coming off may be performed by a retaining ring fitted to the shaft 1 or welding (not shown), not depending on the caulking portion 1b. May be just press fit.

According to the cam follower having this configuration, since the inner ring 2 is provided with both flanges and is press-fitted and fixed to the shaft 1 as a shell shape, it is not necessary to provide the shaft 1 with a flange or a step for fixing the flange, and the shaft 1 has a simple shape. Thus, processing costs such as turning and grinding are reduced, and costs can be reduced. In addition, since the inner ring 2 is provided and the outer diameter surface of the shaft 1 does not directly become a roller rolling surface, it is not necessary to harden by heat treatment, and the cost of heat treatment of the shaft 1 can be reduced, further reducing the cost. It becomes. In addition, since the inner ring 2 has flanges 2b, 2b on both sides, and the outer ring 3 and the roller 4 with cage are incorporated between the flanges 2b, 2b, the cage 5 is not affected even if an induced thrust force acts on the outer ring 3. Is not pinched between the flanges of the inner and outer rings. The contact area between the flanges 2b, 2b of the inner ring 2 and the side surface of the outer ring 3 can be secured to the same level as the conventional standard cam follower, and the wear resistance against the induced thrust load is the same as that of the conventional one with flange. This is superior to a cam follower using a shell type inner ring.
Since the outer ring 3 is made of a steel material, unlike the shell-type outer ring, there is no risk of damage even when a heavy load or impact load is applied from the cam. Since the outer ring 3 has annular recesses 2c and 2c into which the flanges 2b and 2b of the shell-shaped inner ring 2 are fitted on both side surfaces, the flanges 2b and 2b of the shell inner ring 2 do not protrude greatly in the axial direction than the outer ring 3, It can be avoided that the entire width of the roller portion of the cam follower becomes wider than the required width of the driven surface of the outer ring 3.

FIG. 2 shows another embodiment of the present invention. This embodiment is such that, in the cam follower of the embodiment of FIG. 1, one of the flanges 2b of the shell-shaped inner ring 2 is constituted by a separate side plate. That is, in this embodiment, the inner ring body 2A of the shell-shaped inner ring 2 is pressed into an L-shaped cross section having only one flange 2b. After the roller 4 with cage and the solid outer ring 2 are assembled in the inner ring main body 2A, a separate flange 2b 'made of a side plate is pressed or welded to the end face opposite to the end face having the flange 2b. Fixed. Other configurations are the same as those in the embodiment of FIG.
In this embodiment, the case where only one flange 2b 'is configured as a separate side plate is shown, but both flanges 2b may be configured as separate side plates.

FIG. 3 shows still another embodiment of the present invention. In this embodiment, in the cam follower of the embodiment of FIG. 1, a step 1 c for positioning in the axial direction with respect to the support member 7 that supports the base end portion of the shaft 1 is provided on the outer periphery of the shaft 1. The shell-shaped inner ring 2 is simply press-fitted to the shaft 1 and is not fixed in the axial direction by the caulking portion 1b. Other configurations are the same as those in the embodiment of FIG.
The step 1 c is provided at a position closer to the base end supported by the support member 7 than the press-fitted range of the shell-shaped inner ring 2. In the illustrated example, the step 1c is substantially the same axial position as the outer surface of the flange 2b of the shell-shaped inner ring 2, and is slightly closer to the base end than the flange 2b. The step 1c is such that the base end side supported by the support member 7 has a smaller diameter than the other end side where the shell inner ring 2 is press-fitted.

  When the shaft 1 is thus provided with the step 1c, even when the shell-shaped inner ring 2 is fixed to the shaft 1 only by press-fitting, the shaft 1 is inserted into the support member 7 and the male screw portion 1a is tightened with a nut. The axial force due to the support member 7 only acts on the step 1c of the shaft 1 and does not act on the shell-shaped inner ring 2, so that the shell-shaped inner ring 2 can be reliably prevented from falling off in the axial direction.

  FIG. 4 shows still another embodiment of the present invention. In this embodiment, in the cam follower of FIG. 1, a washer 8 for restricting the axial movement of the solid outer ring 3 is provided inside one flange 2b of the two flanges 2b of the shell inner ring 2. The protruding height of one flange 2b toward the outer diameter side is made lower than that of the other flange 2b. In this case, the flange 2b provided with the washer 8 on the inner side is the flange 2b on the side that bends the edge after incorporating the solid outer ring 3 and the roller 4 with cage, and the protruding height is a problem such as cracking at the time of edge bending. Therefore, it can be applied when the height required for the design cannot be secured sufficiently. Other configurations are the same as those in the embodiment of FIG.

  Thus, by providing the washer 8 for restricting the axial movement of the solid outer ring 3 on the inner side of the flange 2b, if the protrusion height of the flange 2b toward the outer diameter side is lowered, the roller 4 with cage and the solid outer ring After the 3 is incorporated into the shell-shaped inner ring 2, it is possible to prevent cracking when the flange 2b is bent, and the shell-shaped inner ring 2 can be manufactured more easily. In this embodiment, the case where the washer 8 is provided on the inner side of the flange 2b near the base end supported by the support member is shown. However, even if the washer 8 is provided on the inner side of the flange 2b on the distal end side, both flanges 2b are provided. You may provide inside.

(A) is a half sectional view of the cam follower according to the first embodiment of the present invention, and (B) and (C) are explanatory views of the procedure for assembling the roller with a cage and the outer ring into the inner ring of the cam follower. It is a half part sectional view of the cam follower concerning other embodiments of this invention. FIG. 6 is a half sectional view of a cam follower according to still another embodiment of the present invention. FIG. 6 is a half sectional view of a cam follower according to still another embodiment of the present invention. It is half sectional drawing of a prior art example. It is sectional drawing of another prior art example. It is explanatory drawing which shows the state supported with the supporting member of the same prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Shaft 1b ... Clamping part 1c ... Level difference 2 ... Shell type inner ring 2b ... Flange 3 ... Solid type outer ring 3b ... Follower surface 4 ... Roller 5 with a cage ... Cage 6 ... Roller 7 ... Support member 8 ... Washer

Claims (8)

  A shaft, a shell-type inner ring fitted into the tip of the shaft in a press-fitted state, an outer ring whose outer peripheral surface is a driven surface, and a roller with a cage interposed between the outer ring and the shell-shaped inner ring And the shell-shaped inner ring has flanges extending to the outer diameter side at both ends, and the outer ring and a roller with a cage are incorporated between both flanges.   The cam follower according to claim 1, wherein the outer ring is made of a cut-out product of a steel material, and has an annular recess into which an inner ring flange fits in an inner diameter portion on each side surface.   The cam follower according to claim 1 or 2, wherein the outer peripheral shape of the shaft is a stepless shape having no step.   3. The cam follower according to claim 1, wherein a step for positioning in the axial direction with respect to a support member that supports a base end portion of the shaft is provided on an outer periphery of the shaft.   The cam follower according to any one of claims 1 to 4, wherein the shell-shaped inner ring is fixed in an axial direction by a caulking portion formed at a tip portion of the shaft.   The cam follower according to any one of claims 1 to 4, wherein the shell-shaped inner ring is fixed in the axial direction by a retaining ring fitted to the shaft or by welding.   The cam follower according to any one of claims 1 to 6, wherein one or both of the flanges at both ends of the shell-shaped inner ring are configured as separate side plates with respect to the shell-shaped inner ring body having a rolling surface. .   The cam follower according to any one of claims 1 to 7, wherein a washer for restricting axial movement of the outer ring is provided on one or both inner sides of both flanges of the shell-shaped inner ring.

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