JPH11141655A - Cam mechanism and roller follower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope with heavy load without being influenced by the parallelism of a driven shaft to a camshaft by forming at least one of the inner surfaces of a shaft through hole and the driven shaft inserted through the shaft through hole, into a curved surface protruded to an axial direction. SOLUTION: A cam 2 is fastened to a camshaft 1, and the camshaft l is supported in such a way as to be rotated integrally with the cam 2. A driven shaft 3 is energized in the cam face direction of the cam 2 while keeping a parallel state to the camshaft 1, and a roller follower 4 is fittingly fixed in a rotatable state to a part corresponding to the cam face of the cam 2. In the roller follower 4, the inner peripheral surface of an inner ring 4a, that is, the inner surface of a shaft through hole, and the outer peripheral surface of an outer ring 4b, that is, the contact face with the cam 2, are respectively made flat in relation to an axial direction. Even in the case of the parallelism of the driven shaft 3 to the camshaft 1 being deviated, there is no part assembled in the state of keeping the point contact relation in all directions, between the driven shaft 3 and the camshaft 1, so that heavy load can be coped with.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cam mechanism using a roller follower and a roller follower used for the cam mechanism.

[0002]

2. Description of the Related Art One of followers used in a cam mechanism includes an inner ring having a shaft insertion hole, and a roller follower having a rotating member interposed between the outer ring and a contact surface provided with a cam. However, in this roller follower, a driven shaft inserted into the shaft insertion hole is arranged in parallel with the cam shaft, and the cam follower and the peripheral surface of the outer ring are assembled in line contact with each other in the axial direction. In this case, if there is any deviation in the parallelism between the driven shaft and the cam shaft, as shown in FIG. 3A, the cam 2 and the roller follower 4 come into point contact only at the outer edge, and are added to the roller follower. Since the stress is biased toward the contact point, the durability is reduced. Therefore, conventionally, as shown in FIG. 3 (b), the outer peripheral surface (contact surface with the cam) of the roller follower 4 is formed as a curved surface in the axial direction, and even if the parallelism is lost, the cam 2 and the roller follower are lost. Attempts have been made to bring the point of contact with No. 4 as close as possible to the center.

[0003]

When the contact point is closer to the center, the bias of the stress is reduced, but the cam surface and the follower are still in point contact, and there is no deviation in the parallelism. Even point contact will occur, and this can only cope with light loads.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a cam mechanism and a roller follower capable of coping with a heavy load without being affected by the parallelism of a driven shaft with respect to a cam shaft. A cam mechanism in which at least one of the inner surfaces of the driven shaft and the shaft insertion hole inserted into the cam mechanism is formed as a curved surface in the axial direction, and the inner surface of the insertion hole is formed as a curved surface in the axial direction. And roller followers formed. It is desirable that the roller follower has a contact surface with the cam formed flat in parallel with the axis.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cam mechanism and a roller follower according to the present invention will be described with reference to the drawings. FIG. 1 shows a cross section of a cam mechanism, wherein 1 is a camshaft.
, A cam 2 is fixed, and the cam shaft 1 is supported so as to rotate integrally with the cam 2. 3 is the camshaft 1
And a driven shaft that is urged to contact the cam surface of the cam 2 using a link or a spring (not shown) while maintaining a parallel state with the cam surface of the cam 2 in the driven shaft 3. A roller follower 4 is rotatably fitted to the corresponding portion.

The roller follower 4 includes an inner ring 4a and an outer ring 4b.
The rollers 4c, 4c,... As rotating members are interposed between the inner and outer wheels 4a, 4b so that the inner and outer wheels 4a, 4b are relatively rotatably assembled with little friction. The inner surface of the hole and the outer peripheral surface of the outer ring 4b, that is, the contact surface with the cam are each formed flat in the axial direction.

In the cam mechanism thus formed, if the camshaft 1 and the driven shaft 3 are parallel, the driven shaft 3 and the roller follower 4 make point contact at the center in the axial direction. It's just However, since the roller follower 4 is assembled in a state where the driven shaft 3 is inserted, the relationship of the line contact perpendicular to the shaft is maintained in the circumferential direction as shown in FIG. It is. If the driven shaft 3 is inclined with respect to the camshaft 1, the camshaft 1 and the roller follower move relative to each other in the circumferential direction as shown in FIG.
However, the line contact does not change, only the line contact along the slope according to the relationship. Therefore, regardless of the parallelism of the driven shaft, it is always assembled in line contact, and the cam 2 and the cam follower 4 are in point contact with each other in the axial direction. You can.

In the above embodiment, the roller follower fitting surface of the driven shaft is formed to be a curved surface in the axial direction, whereby the driven shaft and the roller follower are assembled in a line contact relationship. As shown in FIG. 2, even if the inner peripheral surface of the inner ring 4a in the roller follower 4 is formed to be a curved surface in the axial direction, if the cam shaft 1 and the driven shaft 3 are parallel, the driven shaft 3 and the roller follower 2, the relationship of line contact perpendicular to the axis is maintained in the circumferential direction as shown in FIG. If the driven shaft 3 is inclined with respect to the cam shaft 1, as shown in FIG. 2B, the cam shaft 1 and the roller follower 4 move relative to each other in the circumferential direction. It is assembled in a line contact state along the inclination according to the above, in other words, by using the roller follower, the existing cam mechanism can be modified into the cam mechanism of the present invention without processing the support shaft. It is. In addition, not only one of the driven shaft and the inner peripheral surface of the inner ring of the roller follower may be formed into a curved surface, but also both surfaces may be formed into a curved surface, so that line contact can be achieved, and heavy load can be obtained. Can correspond.

In a special case where the degree of parallelism between the camshaft and the driven shaft is extremely deviated and the contact point in the axial direction hangs on the side edge, the outer circumference of the outer ring on the cam surface or the roller follower is also required. Although it is possible to use it only for light load by making it a curved surface in the axial direction, it is ideal that the outer circumference of the outer ring is formed flat and the roller follower and the cam are in line contact with the axial direction. is there.

[0010] The basic structure of the roller follower is not limited to the embodiment, but may be applied to, for example, a model in which steel balls and needles are employed in addition to a roller as a rotating member.
The present invention is a roller follower in which a rotating member is interposed between the inner ring and the outer ring, but the rotating member is not interposed,
Even when applied to a roller follower consisting of a single ring,
Similar effects can be expected.

[0011]

According to the cam mechanism of the present invention, even if the parallelism of the driven shaft with respect to the camshaft is incorrect, the camshaft is not provided between the driven shaft and the camshaft.
Since there is no part assembled while maintaining the point contact relationship in all directions, it can cope with heavy loads.
Further, according to the roller follower of the present invention, it is possible to provide a cam mechanism capable of coping with a heavy load without processing the driven shaft and without being affected by the parallelism of the driven shaft.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a structure of a cam mechanism according to the present invention.

FIG. 2 is an explanatory diagram of a modified example.

FIGS. 3A and 3B are explanatory diagrams of a conventional example.

[Explanation of symbols]

1 cam shaft, 2 cam, 3 driven shaft, 4 roller follower, 4a inner ring, 4b outer ring, 4c roller.

Claims (3)

[Claims] 1. A cam mechanism using a roller follower in which a rotating member is interposed between an inner ring having a shaft insertion hole and an outer ring provided with a contact surface with a cam, and is inserted through the insertion hole. A cam mechanism in which at least one surface of the driven shaft and the shaft insertion hole in a contact portion between the driven shaft and the shaft insertion hole is formed to be a curved surface in the axial direction. 2. A roller follower having a rotating member interposed between an inner ring having a shaft insertion hole and an outer ring provided with a contact surface with a cam, wherein the inner surface of the shaft insertion hole is A roller follower formed on a curved surface in the direction. 3. The roller follower according to claim 2, wherein the contact surface with the cam is formed parallel to the axis.