JP6818494B2 - Cam follower - Google Patents

Description

The present invention relates to a cam follower.

Conventionally, in various industrial machines and the like, a cam follower that rolls and moves on a cam trajectory formed in an arbitrary shape is known in order to move a movable portion at a desired timing and trajectory. The cam follower has an outer ring rotatably attached to one end of a cam follower stud via a rolling element. In the cam follower, the other end of the cam follower stud is fixed to the movable portion, and the outer ring is cantilevered.

In such a cam follower, an outer rolling surface is formed on the inner peripheral surface of the outer ring. On the outer peripheral surface of the cam follower stud, an inner rolling surface is formed at a position facing the outer raceway surface of the outer ring. A plurality of rolling elements are arranged between the outer rolling surface of the outer ring and the inner rolling surface of the cam follower stud. A collar portion is formed so as to be adjacent to one side end of the inner rolling surface of the cam follower stud. A mounting shaft is formed at the other end of the inner rolling surface of the cam follower stud. Further, a side plate press-fitting portion having an outer diameter larger than the outer diameter of the mounting shaft portion is formed on the mounting shaft portion adjacent to the inner rolling surface. A side plate is press-fitted and fixed to the side plate press-fitting portion so as to face the flange portion. For example, as described in Patent Document 1.

In the side plate of the cam follower described in Patent Document 1, the cam follower stud is press-fitted and a sealing member is provided on the outer periphery to prevent internal grease leakage, and the flange portion and the side plate form an outer ring and a plurality of rolling elements in the axial direction. The movement of is restricted. However, in the configuration described in Patent Document 1, if the tightening margin at the time of press-fitting is large, burrs may occur on the side plate press-fitting portion and the side plate, or the side plate may crack. In addition, a step for providing a side plate press-fitting portion on the cam follower stud is required. On the other hand, in the configuration in which the side plate is not press-fitted into the cam follower stud, a gap may occur between the cam follower stud and the side plate, and the sealing performance may be deteriorated.

Japanese Unexamined Patent Publication No. 2011-027154

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cam follower capable of fixing a side plate to a cam follower stud without damaging the cam follower stud and the side plate.

That is, an outer ring having an outer rolling surface integrally formed on the inner circumference and an inner rolling surface facing the outer rolling surface are integrally formed on the outer circumference at one end in the axial direction of the inner rolling surface. A cam follower stud provided with a flange portion and a support portion having a diameter smaller than the outer diameter of the inner rolling surface at the other end in the axial direction of the inner rolling surface, and the outer rolling surface and the inner rolling surface. A plurality of rolling elements that are rollably accommodated between the surfaces and a side plate that has a hole into which the support portion is inserted and is arranged at the other end in the axial direction of the inner rolling surface. In the cam follower, the inner diameter of the hole in the side plate is larger than the outer diameter of the support portion, and the side plate is fixed to the cam follower stud via an annular elastic body.

The support portion of the cam follower stud is press-fitted into the annular elastic body, and the annular elastic body is press-fitted into the hole of the side plate.

In the cam follower, a diameter-expanded portion into which the annular elastic body is press-fitted is formed in the hole of the side plate.

The cam follower is arranged so that the annular elastic body projects from the side surface of the side plate on the support portion side.

In the cam follower, the annular elastic body is composed of an O-ring.

As the effect of the present invention, the following effects are exhibited.

That is, according to the cam follower, the cam follower stud is not press-fitted into the hole of the side plate. Further, the cam follower is supported by the cam follower stud without the side plate contacting the cam follower stud. As a result, the side plate can be fixed to the cam follower stud without damaging the cam follower stud and the side plate.

According to the cam follower, the axial position of the side plate with respect to the cam follower stud and the axial position of the side plate with respect to the axial center of the cam follower stud are determined without the side plate contacting the cam follower stud. As a result, the side plate can be fixed to the cam follower stud without damaging the cam follower stud and the side plate.

According to the cam follower, the position of the annular elastic body with respect to the side plate is determined, and the annular elastic body is held by the side plate. As a result, the side plate can be fixed to the cam follower stud without damaging the cam follower stud and the side plate.

According to the cam follower, when the cam follower is fixed to the support member, the annular elastic body is compressionally deformed and the frictional force between the annular elastic body and the side plate and the frictional force between the annular elastic body and the cam follower stud. Increases. As a result, the side plate can be fixed to the cam follower stud without damaging the cam follower stud and the side plate.

According to the cam follower, the side plate is fixed to the cam follower stud by the O-ring, and the space between the side plate and the cam floor stud is sealed by the O-ring. As a result, the side plate can be fixed to the cam follower stud while maintaining the sealing performance without damaging the cam follower stud and the side plate.

The perspective view which shows the whole structure in 1st Embodiment of a cam follower. The cross-sectional view which shows the whole structure in 1st Embodiment of a cam follower. An enlarged cross-sectional view showing the dimensions of a side plate and an O-ring in the first embodiment of a cam follower. The enlarged sectional view which shows the press-fitting state of the O-ring in 1st Embodiment of a cam follower. (A) An enlarged cross-sectional view showing a press-fitting state of the O-ring in the second embodiment of the cam follower, and (b) an enlarged cross-sectional view showing a press-fitting state of the O-ring when it is also attached to the mounting member.

Hereinafter, the cam follower 1 which is the first embodiment of the cam follower will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the cam follower 1 rolls on a cam orbit in a cam mechanism used in an automatic machine or the like to guide a movable portion, or guides a transported object as a guide roller. The cam follower 1 includes an outer ring 2, a cam follower stud 3, a rolling element 4 (see FIG. 2) composed of a plurality of needle rollers, a side plate 5, an O-ring 6, and a sealing member 7.

As shown in FIG. 2, the outer ring 2 rolls on a cam orbit (not shown). The outer ring 2 is formed in a substantially cylindrical shape. The outer ring 2 is formed of, for example, a high carbon chrome bearing steel such as SUJ2. Further, the outer ring 2 is hardened in the range of 58 to 64 HRC up to its core portion by quenching (for example, sub-quenching) at the time of manufacture. As a result, the outer ring 2 has sufficient mechanical strength against a load, and the durability is improved.

An annular outer rolling surface 2a is formed on the inner peripheral surface of the outer ring 2 in the circumferential direction. Outer ring enlarged diameter portions 2b having an inner diameter larger than the inner diameter of the portion where the outer rolling surface 2a is formed are formed at both ends in the axial direction of the outer ring 2. As a result, outer ring stepped surfaces 2c having an enlarged inner peripheral surface are formed at both side ends of the outer rolling surface 2a. Further, each outer ring enlarged diameter portion 2b is formed with an annular sealing groove 2d into which the sealing member 7 can be fitted. A contact surface 2e that rolls on the raceway surface of a cam (not shown) is formed on the outer peripheral surface of the outer ring 2.

The cam follower stud 3 rotatably supports the outer ring 2. The cam follower stud 3 is formed in a shaft shape having different shaft diameter portions. The cam follower stud 3 is formed of, for example, a high carbon chrome bearing steel such as SUJ2. Further, the cam follower stud 3 is hardened in the range of 58 to 64 HRC up to its core portion by quenching (for example, sub-quenching) at the time of manufacture. As a result, the cam follower stud 3 has sufficient mechanical strength against a bending load, and the durability is improved.

An annular inner rolling surface 3a is formed on the outer peripheral surface of one side end of the cam follower stud 3. A collar portion 3b is formed at one side end of the inner rolling surface 3a, which is one side end of the cam follower stud 3. The outer diameter of the flange portion 3b is smaller than the inner diameter of the outer ring enlarged diameter portion 2b of the outer ring 2 and larger than the inner diameter of the portion of the outer ring 2 on which the outer rolling surface 2a is formed. At the other end of the inner rolling surface 3a, a support portion 3c having an outer diameter D1 smaller than the outer diameter of the portion where the inner rolling surface 3a is formed is formed. As a result, a shaft step surface 3d is formed at the other end of the inner rolling surface 3a. At the other end of the support 3c, a screw portion 3e for attaching to a mounting member 100 such as a cam lever of a cam mechanism is formed. A refueling passage 3f that communicates from the other end of the screw portion 3e to the inner rolling surface 3a is formed in the axial center portion of the cam follower stud 3. The cam follower stud 3 is arranged so that the inner rolling surface 3a faces the outer rolling surface 2a of the outer ring 2. Further, the cam follower stud 3 is arranged inside the outer ring enlarged diameter portion 2b of the outer ring 2 in a state where the shaft side surface of the flange portion 3b faces the outer ring stepped surface 2c of the outer ring 2.

The rolling element 4 composed of a plurality of needle roller bearings rotatably supports the outer ring 2. The rolling element 4 is held in an annular shape by a cage. The rolling element 4 is formed of, for example, a high carbon chrome bearing steel such as SUJ2. Further, the rolling element 4 is hardened in the range of 58 to 64 HRC up to its core portion by quenching (for example, sub-quenching) at the time of manufacture. The rolling element 4 is rotatably sandwiched between the outer rolling surface 2a formed on the outer ring 2 and the inner rolling surface 3a of the cam follower stud 3 facing the outer rolling surface 2a. That is, the rolling element 4 is housed between the outer rolling surface 2a and the inner rolling surface 3a, and rotatably supports the outer ring 2 with respect to the cam follower stud 3.

The side plate 5 regulates the axial movement of the outer ring 2 and the rolling element 4. The side plate 5 is formed in a disk shape having a hole 5a in the center. The side plate 5 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C. The side plate 5 is hardened in the range of 58 to 64 HRC up to its core portion by quenching (for example, sub-quenching) at the time of manufacture. The outer diameter of the side plate 5 is smaller than the inner diameter of the outer ring enlarged diameter portion 2b of the outer ring 2 and larger than the inner diameter of the portion of the outer ring 2 on which the outer rolling surface 2a is formed. Further, a side plate enlarged diameter portion 5b having an inner diameter d2 that is larger than the inner diameter d1 of the hole 5a is formed at one side end portion of the hole 5a (see FIG. 3). As a result, the hole 5a is formed with a side plate stepped surface 5c having an enlarged inner peripheral surface.

The support portion 3c of the cam follower stud 3 is inserted into the hole 5a of the side plate 5. The side plate 5 is arranged at a position where the plate surface on the side where the side plate enlarged diameter portion 5b is not formed comes into contact with the shaft stepped surface 3d of the cam follower stud 3. As a result, the side plate 5 is arranged inside the outer ring enlarged diameter portion 2b of the outer ring 2 in a state where the plate surface on the side where the side plate enlarged diameter portion 5b is not formed faces the outer ring stepped surface 2c of the outer ring 2.

The O-ring 6 (thin ink portion), which is an annular elastic body, fixes the side plate 5 and seals the gap between the hole 5a of the side plate 5 and the support portion 3c of the cam follower stud 3. The O-ring 6 is formed of, for example, a synthetic rubber such as NBR (acrylonitrile-butadiene rubber). The support portion 3c of the cam follower stud 3 is press-fitted into the O-ring 6. At the same time, the O-ring 6 is press-fitted into the side plate enlarged diameter portion 5b of the side plate 5.

A sealing member 7 is provided in a gap between the outer ring 2 and the flange portion 3b of the cam follower stud 3 and a gap between the outer ring 2 and the side plate 5. The seal member 7 is formed in an annular shape having a seal lip on the inner peripheral surface. The sealing member 7 is formed of, for example, a synthetic rubber such as NBR (acrylonitrile-butadiene rubber). The seal member 7 is press-fitted into each seal groove 2d of the outer ring 2. The seal lip of the seal member 7 press-fitted into the seal groove 2d on one side is in contact with the outer peripheral surface of the flange portion 3b of the cam follower stud 3. The seal lip of the seal member 7 press-fitted into the seal groove 2d on the other side is in contact with the outer peripheral surface of the side plate 5. As a result, the sealing member 7 seals the gap between the outer ring 2 and the flange portion 3b and the gap between the outer ring 2 and the side plate 5.

Next, the fitting of the cam follower stud 3, the side plate 5, and the O-ring 6 will be described with reference to FIGS. 3 and 4.

As shown in FIG. 3, the inner diameter d1 of the hole 5a is larger than the outer diameter D1 of the support portion 3c of the cam follower stud 3. Further, the inner diameter d2 of the side plate enlarged diameter portion 5b of the holes 5a is larger than the inner diameter d1 of the holes 5a. The outer diameter D2 of the O-ring 6 is smaller than the outer diameter D1 of the support portion 3c of the cam follower stud 3, and is larger than the inner diameter d2 of the side plate enlarged diameter portion 5b of the side plate 5.

As shown in FIG. 4, by interposing the O-ring 6 between the side plate enlarged diameter portion 5b and the support portion 3c, the side plate 5 is formed between the inner peripheral surface of the hole 5a and the outer peripheral surface of the support portion 3c. It is arranged so that a gap Δd1 = (d1-D1) / 2 is generated.

The support portion 3c of the cam follower stud 3 is press-fitted into the O-ring 6. The inner diameter of the O-ring 6 is increased by the tightening allowance Δd3 = d3-D1 with respect to the support portion 3c, and the inner peripheral surface of the O-ring 6 presses the outer peripheral surface of the support portion 3c by the reaction force (see the black arrow). ). As a result, a frictional force is generated between the inner peripheral surface of the O-ring 6 and the outer peripheral surface of the support portion 3c due to the pressing force.

At the same time, the O-ring 6 is press-fitted into the side plate enlarged diameter portion 5b of the side plate 5. The outer diameter of the O-ring 6 is reduced by the tightening allowance ΔD2 = d2-D2 with respect to the side plate enlarged diameter portion 5b, and the outer peripheral surface of the O-ring 6 presses the inner peripheral surface of the side plate enlarged diameter portion 5b by the reaction force. (See black arrow). As a result, a frictional force is generated between the outer peripheral surface of the O-ring 6 and the inner peripheral surface of the side plate enlarged diameter portion 5b due to the pressing force. That is, the O-ring 6 fixes the side plate 5 at a position where the side plate 5 comes into contact with the shaft stepped surface 3d of the cam follower stud 3 by a frictional force in a state where the side plate 5 is separated from the cam follower stud 3 by a gap Δd1.

In the cam follower 1 configured in this way, the outer ring 2 is rotatably supported by the cam follower stud 3 via the rolling element 4. Further, the cam follower 1 is restricted from moving in the axial direction of the outer ring 2 and the rolling element 4 by the flange portion 3b and the side plate 5 of the cam follower stud 3 arranged so as to face the outer ring step surface 2c of the outer ring 2 in the axial direction. Has been done. The support portion 3c of the cam follower stud 3 is inserted into the hole 5a of the side plate 5 with a gap Δd1, and the side plate 5 is supported by the O-ring 6. That is, the side plate 5 is fixed to the cam follower stud 3 via the O-ring 6 without contacting the cam follower stud 3. Therefore, in the cam follower 1, it is not necessary to press-fit the cam follower stud 3 into the hole 5a of the side plate 5. Further, in the cam follower 1, the cam follower stud 3 is press-fitted into the O-ring 6, and the O-ring 6 is press-fitted into the side plate enlarged diameter portion 5b of the side plate 5, so that the position of the O-ring 6 with respect to the side plate 5 and the side plate with respect to the cam follower stud 3 are formed. The axial position of 5 and the position of the axial center of the side plate 5 with respect to the axial center of the cam follower stud 3 are determined. As a result, the side plate 5 can be fixed at an arbitrary position of the cam follower stud 3 without damaging the cam follower stud 3 and the side plate 5.

The cam follower 8 which is the second embodiment of the cam follower will be described below with reference to FIG. It should be noted that the cam follower 8 according to the following embodiment is applied in place of the cam follower 1 in the cam follower 1 shown in FIGS. 1 to 4, by using the names, drawing numbers, and symbols used in the description thereof. In the following embodiments, the same points will be referred to, and the same points as those in the embodiments already described will be omitted, and the differences will be mainly described.

As shown in FIG. 5A, the side plate 9 regulates the axial movement of the outer ring 2 and the rolling element 4. The side plate 9 is formed in a disk shape having a hole 9a in the center. At one side end of the hole 9a, a side plate diameter-expanded portion 9b having an inner diameter d2 larger than the inner diameter d1 of the hole 9a and an axial length L is formed. As a result, the hole 9a is formed with a side plate stepped surface 9c having an enlarged inner peripheral surface at a position of an axial length L from the plate surface of the side plate 9.

The O-ring 10, which is an annular elastic body, fixes the side plate 9 and seals the gap between the hole 9a of the side plate 9 and the cam follower stud 3. The wire diameter D3 of the O-ring 10 is larger than the axial length L of the side plate enlarged diameter portion 9b of the side plate 9.

The support portion 3c of the cam follower stud 3 is press-fitted into the O-ring 10. At the same time, the O-ring 10 is press-fitted into the side plate enlarged diameter portion 9b of the side plate 9. At this time, the O-ring 10 protrudes from the plate surface of the side plate 9 (the end surface of the side plate 9 on the support portion 3 side) by ΔD3 = D3-L.

As shown in FIG. 5B, in the cam follower 8, the cam follower stud 3 is fixed to the mounting member 100 including the cam lever of the cam mechanism by screwing. In the cam follower 8, axial tension is generated in the cam follower stud 3 by fastening the nut of the screw portion 3e (see FIG. 2). That is, in the cam follower 8, the side plate 9 is pressed against the side surface of the mounting member 100 by the tension. At this time, in the cam follower 8, the O-ring 10 is sandwiched between the side plate stepped surface 9c of the side plate 9 and the side surface of the mounting member 100 and crushed (pressed). As a result, the O-ring 10 is deformed so as to expand toward the outer peripheral surface of the support portion 3c of the cam follower stud 3, the inner peripheral surface of the side plate enlarged diameter portion 9b of the side plate 9, and the side plate stepped surface 9c. Then, in the cam follower 8, the frictional force generated between the inner peripheral surface of the O-ring 10 and the outer peripheral surface of the support portion 3c, and between the outer peripheral surface of the O-ring 10 and the inner peripheral surface of the side plate enlarged diameter portion 9b. The frictional force generated in the O-ring 10 and the frictional force generated between the axial side surface of the O-ring 10 and the side plate stepped surface 9c increase. As a result, the cam follower 8 can firmly fix the side plate 9 to the cam follower stud 3 without damaging the cam follower stud 3 and the side plate 9.

As described above, the cam followers 1 and 8 according to the present embodiment use the O-rings 6 and 10 as the annular elastic member, but the cam followers 1 and 8 may be other than the O-ring 10 as long as they are the annular elastic members. Further, the cam followers 1 and 8 have been described as having the collar portion 3b integrally formed on the cam follower stud 3, but the present invention is not limited to this, and the cam followers 1 and 8 may be configured separately from the cam follower stud 3. The above-described embodiment merely shows a typical embodiment of the present invention, and various modifications such as materials and heat treatment methods can be carried out within a range that does not deviate from the gist of the present invention.

1,8 Cam follower 2 Outer ring 2a Outer rolling surface 3 Cam follower stud 3a Inner rolling surface 3b Collar 3c Support 4 Roller 5,9 Side plate 5a, 9a Hole 6,10 O-ring

Claims (4)

An outer ring with an outer rolling surface integrally formed on the inner circumference,
An inner rolling surface facing the outer rolling surface is integrally formed on the outer periphery, a flange portion is provided on one side end of the inner rolling surface in the axial direction, and the other side end of the inner rolling surface in the axial direction. A cam follower stud provided with a support portion whose diameter is smaller than the outer diameter of the inner rolling surface, and
A plurality of rolling elements that are rotatably accommodated between the outer rolling surface and the inner rolling surface,
In a cam follower having a hole into which the support portion is inserted and having a side plate arranged at the other side end in the axial direction of the inner rolling surface.
The inner diameter of the hole in the side plate is larger than the outer diameter of the support portion.
The side plate is fixed to the cam follower stud via an annular elastic body, and the side plate is fixed to the cam follower stud .
A cam follower in which the annular elastic body is arranged so as to project from the side surface of the side plate on the support portion side . The cam follower according to claim 1, wherein the support portion of the cam follower stud is press-fitted into the annular elastic body, and the annular elastic body is press-fitted into the hole of the side plate. The cam follower according to claim 1 or 2, wherein a diameter-expanded portion into which the annular elastic body is press-fitted is formed in the hole of the side plate. The cam follower according to any one of claims 1 to 3 , wherein the annular elastic body is formed of an O-ring.

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