JPH11218158A - Roller clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of a slip even under long-term use by forming a carburized layer or a carbonitrided layer with specified hardness and depth on at least one of the inner peripheral surface of an outer ring equivalent member and the outer peripheral surface of an inner ring equivalent member. SOLUTION: A plurality of rollers 3, cages 5 and springs 4 for pressing the rollers 3 in the same circumferential direction are provided in a cylindrical clearance 12 between the cylindrical surface of a shaft 6 and a cam face 7 with unevenness in the circumferential direction of the inner peripheral surface of an outer ring 2. A carburized layer or a carbonitrided layer with a hardness of Hv550 or more and a depth of 0.20 mm or more is formed at least at one surface layer part of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6. Accordingly, when the roller 3 bites in wedge shape into the clearance 12, the depth of the layer is deeper than the arrival position of shearing stress or the like applied from the rolling surface of the roller 3 so as to suppress the formation of impression on at least one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6. The roller 3 is therefore put in a normal mesh state in the clearance 12 so as to suppress the slip of the outer ring 2 and shaft 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION A roller clutch according to the present invention comprises two members concentrically combined with each other.
When one member makes a bidirectional rotational movement, it is used when only one of the rotational movements is transmitted to the other member. In particular, the present invention relates to a fully automatic washing machine, a fishing gear reel, a lawnmower, an auxiliary machine for an automobile, and the like, in which the clutch is instantaneously engaged (connected state) from a state in which the clutch is overrun at high speed (disconnected state). It is intended to improve the durability of a roller clutch incorporated in such a mechanical portion or a mechanical portion in which the overrun state and the meshing state are repeated many times in a short time even at a low speed.

[0002]

2. Description of the Related Art Facsimile machines, paper feed mechanisms for copiers, etc.
Roller clutches that transmit only rotational motion in a specific direction are incorporated in various mechanical devices. 1 to 3 show an example of a conventionally known roller clutch 1. The roller clutch 1 includes an outer ring 2 corresponding to an outer ring, a plurality of rollers 3,
And the same number of springs 4, 4, a retainer 5, and a shaft 6 as an inner ring equivalent member. The outer ring 2 is formed into a cylindrical shape from a cold-rolled steel plate or a strip steel or a special steel plate or a strip steel. When used, the inner peripheral surface of the outer ring 2 is a cylindrical surface such as a bearing housing provided at the center of the paper feed roller. Is fixed inside the holding member (not shown). The inner peripheral surface of the outer ring 2 is a cam surface 7 which is uneven in the circumferential direction. That is, at a plurality of locations on the inner peripheral surface of the outer ring 2, concave portions 8, called ramp portions, are formed at equal intervals along the axial direction of the outer ring 2 and in the circumferential direction. Further, flange portions 9 are formed at both axial ends of the outer ring 2 by bending a metal plate constituting the outer ring 2 inward in the diameter direction. The plurality of rollers 3,3, the same number of springs 4,4 as the respective rollers 3,3, the retainer 5, and the shaft 6
Is provided inside the outer ring 2 in the diameter direction as described above.

The cage 5 is cage-shaped and formed into a cylindrical shape by injection molding synthetic resin. The retainer 5 is mounted inside the outer ring 2 so as to be unable to rotate relative to the outer ring 2. For this reason, the cage 5
Projections are formed at a plurality of positions on the outer peripheral surface of each of the above, and these projections are engaged with the recesses 8. The plurality of rollers 3, 3 are provided with pockets 10 formed in such a retainer 5,
Roller 10 and a small amount of displacement in the circumferential direction are held inside 10. The springs 4, 4 are provided between the pillars 11, 11, which constitute the retainer 5 as described above, and the rollers 3, 3, and the rollers 3, 3 are arranged in the circumferential direction. They are elastically pressed in the same direction. FIG.
In FIGS. 3 to 3, each of the springs 4 and 4 is illustrated as a coil spring in order to schematically show the springs. However, in actual cases, these springs 4 and 4 are strip-shaped spring plates as shown in FIG. U
It is a stainless steel leaf spring which is folded in a letter shape or a letter shape, or a synthetic resin spring formed integrally with the retainer 5.

When the roller clutch is used, the outer ring 2
And the shaft 6 is inserted through the inside of the plurality of rollers 3. In this state, a cylindrical gap 12 is formed between the outer peripheral surface of the shaft 6 and the inner peripheral surface of the outer ring 2. With the dimensions of this cylindrical gap 12,
The width dimension of the outer ring 2 in the diametrical direction (the vertical direction in FIGS. 1 to 3) is larger than the outer diameter of each of the rollers 3, 3 at a portion corresponding to each of the concave portions 8, 8, and from these concave portions 8, 8, The outside diameter of each of the rollers 3, 3 is smaller than the outer diameter of each roller.

[0005] The roller clutch 1 constructed as described above is
Only the relative rotation of the shaft 6 in the predetermined direction between the holding member in which the outer ring 2 is fixedly fitted and the shaft 6 is transmitted. For example, in FIG.
Is fixed and only the shaft 6 rotates, and if the shaft 6 rotates clockwise in FIG.
Based on the force that the shaft 3 receives from the outer peripheral surface of the shaft 6, the spring 3 tends to be displaced toward the openings of the recesses 8 and 8 against the elasticity of the springs 4 and 4 respectively. And each of the rollers 3,
3 becomes movable within the cylindrical gap 12, and a so-called overrun state occurs in which the transmission of rotational force between the outer ring 2 and the shaft 6 is stopped. Conversely, when the shaft 6 rotates in the counterclockwise direction in FIG. 2, the rollers 3, 3 receive the force received from the outer peripheral surface of the shaft 6 and the elasticity of the springs 4, 4 based on: The outer ring 2 and the shaft 6 are integrally coupled with each other by wedge-like biting into a part of the closing portion of each of the recesses 8, 8 so that the rotational force can be freely transmitted between the outer ring 2 and the shaft 6. In a so-called locked state.

In the roller clutch 1 described above, the cam surface 7 is formed on the inner peripheral surface of the outer ring 2, and the outer peripheral surface of the shaft 6 is a cylindrical surface. However, the peripheral surface forming the cam surface may be reversed. .
That is, as shown in FIG. 4, concave portions 8a, 8a are formed on the outer peripheral surface of an inner ring 13 which is an inner ring equivalent member, the outer peripheral surface of the inner ring 13 is used as a cam surface 7a, and the inner peripheral surface of the outer ring 2a is formed. It is simply a cylindrical surface. Roller clutch 1a having such a structure
In use, the outer ring 2a is internally fitted and fixed to the holding member, and the inner ring 13 is externally fitted and fixed to the shaft.

In either case of the roller clutch 1 shown in FIGS. 1 to 3 or the roller clutch 1a shown in FIG. 4, the inner peripheral surfaces of the outer races 2 and 2a and the outer peripheral surface of the shaft 6 or the inner race 13 are formed. It is hardened by carburizing or carbonitriding. That is, the steel plate is subjected to deep drawing, or the inner peripheral surfaces of the outer races 2 and 2a and the outer peripheral surfaces of the shaft 6 and the inner race 13 made of a drawn material are hardened by carburizing treatment or carbonitriding treatment. These peripheral surfaces are prevented from being damaged by the load applied from the rolling surfaces of the rollers 3 and 3. However, the outer rings 2 and 2 constituting the conventional roller clutch
The depth of the hardened layer formed by carburizing or carbonitriding on the inner peripheral surface of a and the outer peripheral surface of the shaft 6 or the inner ring 13 was extremely shallow.

[0008]

For example, in the case of a roller clutch incorporated in a paper feed mechanism, the required torque capacity is small, and the cycle in which the clutch is overrun and engaged is repeated at 150 cp.
m (150 times per minute).
Even if the thickness of the hardened layer formed on the inner peripheral surface of a and the outer peripheral surface of the shaft 6 or the inner ring 13 is small, sufficient durability can be obtained.

[0009] On the other hand, a mechanical unit such as a fully automatic washing machine, a reel of fishing gear, a lawnmower, an auxiliary machine for an automobile, etc., in which the clutch is instantaneously engaged from a state in which the clutch is overrunning at high speed. In the case of a roller clutch incorporated in a mechanism in which the overrun state and the meshing state are repeated many times in a short time even at a low speed, sufficient durability may not be obtained. That is, in the case of a roller clutch used for such an application, the inner peripheral surfaces of the outer rings 2 and 2a and the shaft 6
Alternatively, the outer peripheral surface of the inner ring 13 is plastically deformed based on an impact load repeatedly applied from the rolling surfaces of the rollers 3, and indentations are formed on these peripheral surfaces. Then, based on the presence of the indentation, the contact state between the peripheral surface and the rolling surface of each of the rollers 3 and 3 becomes irregular. Without becoming a regular meshing state,
There is a possibility that the outer ring 2, 2a and the shaft 6 or the inner ring 13 may slip. In view of such circumstances, the present invention is not limited to the inner peripheral surface of the outer ring 2, 2a and the outer peripheral surface of the shaft 6 or the inner ring 13 regardless of the impact load repeatedly applied from the rolling surfaces of the rollers 3, 3. By making it difficult for indentations to be formed on one or both of the peripheral surfaces, the outer ring 2,
The present invention has been invented to prevent the occurrence of slip between the shaft 2a and the shaft 6 or the inner ring 13.

[0010]

A roller clutch according to the present invention is similar to the conventional roller clutch described above, for example, as shown in FIG.
3 or FIG. 4, the outer ring 2 which is an outer ring equivalent member.
And an inner ring-equivalent member disposed concentrically with the outer ring 2 inside the outer ring 2. The inner ring-equivalent member is the same as the inner ring 13 itself as shown in FIG.
Also, the case of the shaft 6 as shown in FIGS. Also, the outer ring 2
Cam surfaces 7 and 7a formed on one of the inner peripheral surface of the shaft 6 and the outer peripheral surface of the inner ring 13 and having irregularities in the circumferential direction, and the inner peripheral surface of the outer ring 2 and the shaft. 6 or a cylindrical surface formed on the other outer peripheral surface of the inner ring 13. Further, a plurality of rollers 3 provided in a cylindrical gap 12 between the cylindrical surface and the cam surfaces 7 and 7a, and a member provided with the cam surfaces 7 and 7a, that is, FIG. 4, the outer ring 2 cannot be rotated with respect to the inner ring 13 in the structure shown in FIG.
A holder 5 for holding the plurality of rollers 3 is provided. Further, springs 4 and 4 are provided between the retainer 5 and the rollers 3 and press the rollers 3 and 3 in the same direction with respect to the circumferential direction.

In particular, in the roller clutch of the present invention, the hardness of the surface layer of at least one of the inner peripheral surface of the outer race 2 and the outer peripheral surface of the shaft 6 or the inner race 13 is increased.
A carburized layer or a carbonitrided layer having an Hv of 550 or more and a depth of 0.20 mm or more is formed. Such a condition is effective when applied to a roller clutch in which the outer ring 2 or the inner ring 13 forming the carburized layer or the carbonitrided layer has a plate thickness of 0.5 mm or more. Providing a carburized layer or a carbonitrided layer that satisfies the above-described conditions is effective to some extent even on one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13. Can be obtained. However, on both sides,
If the above-mentioned carburized layer or carbonitrided layer is provided, more excellent functions and effects can be obtained.

Further, satisfying one or more of the following conditions is also effective for solving the above-mentioned problem. A carburized layer or a carbonitrided layer having a hardness of Hv 550 or more and a depth of 0.20 mm or more is formed on at least one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13. In addition, the hardness of the core of the member having the peripheral surface is Hv
300 or more. A carburized layer or a carbonitrided layer having a hardness of Hv 550 or more and a depth of 0.20 mm or more is formed on at least one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13. In addition, at least one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13 and the rolling surface of each of the rollers 3 and 3 is subjected to hard shot peening, barrel, sand blast, and tumbler. The surface is work-hardened by performing any one of the processes selected from among them, and the hardness of the surface layer in a range of 0 to 50 μm from the surface of this surface is set to Hv.
830 to 960, compressive residual stress of -50 to -110 kgf /
mm ² and the average wavelength is 25 μm. A carburized layer or a carbonitrided layer having a hardness of Hv 550 or more and a depth of 0.20 mm or more is formed on at least one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13, In addition to the hardness of the core of the member having the peripheral surface being Hv300 or more, at least one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13 and the rolling surface of each roller. By subjecting the surface to any processing selected from hard shot peening, barrel, sand blast, and tumbler, the surface is work-hardened, and the surface layer portion within a range of 0 to 50 μm from the surface of this surface Hv83 hardness
0 to 960, compressive residual stress of -50 to -110 kgf / mm
^{2. The} average wavelength is 25 μm.

[0013]

The function of the roller clutch 1, 1a of the present invention having the above-described structure to transmit only one-way rotational motion between the outer ring 2 and the shaft 6 or the inner ring 13 is the same as that of the above-described conventional roller clutch. Same as in the case. In particular, in the case of the roller clutches 1 and 1a of the present invention, carburization having a hardness of Hv 550 or more is formed on at least one of the inner peripheral surface of the outer race 2 and the outer peripheral surface of the shaft 6 or the inner race 13. Layer or carbonitrided layer having a depth of 0.20 mm or more and a roller clutch 1,
In order to bring 1a into a connected state, each roller 3, 3 is a cylindrical gap 1 between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13.
When the wedges bite into the narrowed portion of the roller 2, the depth is deeper than the position where the stress such as the shear stress applied from the rolling surface of each of the rollers 3, 3 reaches. Therefore, at the moment when the roller clutches 1 and 1a shift from the overrun state to the connected state,
Irrespective of the large surface pressure applied from the rolling surfaces of the rollers 3, indentations are not easily formed on at least one of the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 or the inner ring 13. Become. As a result, the contact state between the peripheral surface and the rolling surface of each of the rollers 3, 3 is less likely to be irregular, and the rollers 3, 3 are in a normal meshing state in the cylindrical gap 12. The outer ring 2 and the shaft 6 or the inner ring 13 are less likely to slip.

Further, even when the hardness of the outer ring 2 or the shaft 6 or the core of the inner ring 13 is set to Hv300 or more, indentations are hardly formed on the inner peripheral surface of the outer ring 2 or the outer peripheral surface of the shaft 6 or the inner ring 13. Thus, the occurrence of the slip can be suppressed. Further, at least one of the inner peripheral surface of the outer race 2 and the outer peripheral surface of the shaft 6 or the inner race 13 and the rolling surface of each of the rollers 3 is within a range of 0 to 50 μm from the surface of the surface. The hardness of the surface layer is Hv 830 to 960, and the compressive residual stress is -50 to-
When 110 kgf / mm ² and the average wavelength are 25 μm,
By increasing the surface hardness, not only the indentation resistance (the difficulty of forming indentations) can be improved, but also the lubricity associated with retaining the lubricating oil in the fine concave portions present on the surface can be improved. Moreover, at the moment when the roller clutches 1 and 1a shift from the overrun state to the connected state due to the relaxation of the stress concentration due to the fine projections existing on the surface and the compressive residual stress,
Regardless of the large surface pressure applied from the rolling surfaces of the rollers 3, 3, the occurrence of fretting wear on the surfaces can be prevented, and the occurrence of the slip can also be suppressed.

[0015]

EXAMPLES The results of experiments conducted to confirm the effects of the present invention will be described. In the experiments, a roller clutch 1 as shown in FIGS. 1 to 3 was used, and carbonitriding was performed on the inner peripheral surface of an outer ring 2 formed of a special polished steel band (chromium molybdenum steel), which constitutes the roller clutch 1. Among the hardened layers formed as treatment layers, the depth of the hardened layer (effective hardened layer) having a hardness of Hv 550 or more and the maximum value of the surface pressure applied from the rolling surface of each of the rollers 3 and 3 to each of the peripheral surfaces are described. Various changes were made. Then, the influence of the depth of the effective hardened layer and the maximum value of the surface pressure on the formation of the indentation on both the peripheral surfaces was examined. Incidentally, the axial dimension L ₂ of the outer ring 2 constituting the roller clutch 1 used in the experiment 16 mm, an outer diameter D ₀ is 26m
m, the material of the outer ring 2 is a cold-rolled special use steel strip, the maximum thickness is 1 mm, the number of the rollers 3, 3 is 17, and the axial length of each of the rollers 3, 3 is 10.9 mm. The outer diameter of the shaft 6 inserted inside the outer ring 2 was 20 mm.

The results of the experiment conducted under the above conditions are as follows:
As shown in FIG. In FIG. 5, white circles indicate the cases in which the occurrence of indentations leading to the slippage of the roller clutch 1 was observed, and black circles indicate the cases in which such indentations were not observed. As is apparent from FIG. 5, the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the shaft 6 constituting the roller clutch 1 are formed as carbonitrided layers having a depth of 0.20 mm. By forming the hardened layer, it is possible to prevent the formation of indentations on each of these peripheral surfaces which may lead to slippage of the roller clutch, and to realize a roller clutch having excellent durability.

[0017]

Since the present invention is constructed and operates as described above, a highly reliable and durable roller clutch can be realized, and the performance of various devices incorporating the roller clutch can be stabilized. From the opposite side, by reducing the size of each component of the roller clutch while maintaining reliability and durability, the size of the roller clutch as a whole is reduced, and various types of mechanical devices incorporating the roller clutch. Can be made easier.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first example of a roller clutch to which the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view of a portion B in FIG. 2;

FIG. 4 is a sectional view showing a second example of the roller clutch to which the present invention is applied.

FIG. 5 is a graph showing the results of an experiment performed to confirm the effects of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 1a Roller clutch 2, 2a Outer ring 3 Roller 4 Spring 5 Cage 6 Shaft 7, 7a Cam surface 8, 8a Depression 9 Flange part 10 Pocket 11 Column part 12 Cylindrical gap 13 Inner ring

Claims (4)

[Claims] 1. An outer ring-equivalent member, an inner ring-equivalent member disposed concentrically with the outer ring-equivalent member inside the outer ring-equivalent member, and an inner peripheral surface of the outer ring-equivalent member and an outer peripheral surface of the inner ring-equivalent member. And a cylinder formed on the other of the inner peripheral surface of the outer ring equivalent member and the outer peripheral surface of the inner ring equivalent member. Surface, a plurality of rollers provided in a cylindrical gap between the cylindrical surface and the cam surface, and is supported in the cylindrical gap so that rotation with respect to a member on which the cam surface is formed is disabled, In a roller clutch including a retainer that holds the plurality of rollers and a spring that is provided between the retainer and each of the rollers and presses each of the rollers in the same direction with respect to a circumferential direction, Between the inner peripheral surface of the outer ring equivalent member and the inner ring equivalent member. At least one of the outer peripheral surfaces has a hardness of Hv550 or more and a depth of 0.20 mm.
A roller clutch comprising the above-described carburized layer or carbonitrided layer. 2. The hardness of at least one of the inner peripheral surface of the outer ring equivalent member and the outer peripheral surface of the inner ring equivalent member is Hv5.
2. The roller clutch according to claim 1, wherein, in addition to forming a carburized layer or a carbonitrided layer having a depth of at least 50 and a depth of at least 0.20 mm, the hardness of the core of the member having the peripheral surface is Hv300 or more. . 3. The hardness of at least one of the inner peripheral surface of the outer ring member and the outer peripheral surface of the inner ring member is Hv5.
In addition to forming a carburized layer or a carbonitrided layer having a depth of 50 mm or more and a depth of 0.20 mm or more, the inner peripheral surface of the outer ring-equivalent member, the outer peripheral surface of the inner ring-equivalent member, and the rolling surface of each roller are formed. At least one of the surfaces is hard-shot-peened, barrel, sandblasted, or tumbler, and the surface is work-hardened by 0 to 50 μm from the surface of the surface. The hardness of the surface layer, which is the range, is Hv 830 to 960, and the compressive residual stress is -5.
The roller clutch according to claim 1, wherein the roller clutch has an average wavelength of 0 to −110 kgf / mm ² and an average wavelength of 25 μm. 4. The hardness of at least one of the inner peripheral surface of the outer ring equivalent member and the outer peripheral surface of the inner ring equivalent member is Hv5.
Forming a carburized layer or a carbonitrided layer having a depth of 50 or more and a depth of 0.20 mm or more, and determining the hardness of the core of the member having the peripheral surface.
In addition to Hv300 or more, at least one of the inner peripheral surface of the outer ring equivalent member, the outer peripheral surface of the inner ring equivalent member, and the rolling surface of each roller is hard shot peened,
The surface is work-hardened by performing any processing selected from barrel, sand blast, and tumbler, and the hardness of the surface layer in a range of 0 to 50 μm from the surface of this surface is Hv 830 to 960, and the compression residual Stress from -50 to-
2. The method according to claim 1, wherein the weight is 110 kgf / mm ² and the average wavelength is 25 μm.
3. The roller clutch according to any one of claims 1 to 3.