JPH0654135B2 - One way clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is mainly used for a portion transmitting a relatively low torque, such as a drive mechanism of an audiovisual device such as a video tape recorder or an audio tape recorder. Regarding a small one-way clutch.

(Prior Art) Conventionally, in this type of one-way clutch, as shown in FIG. 4, a cam surface 22 is formed on the inner peripheral surface of the outer ring 21, and a space formed between the cam surface 22 and the inner ring 26. The mainstream structure is one in which a roller 24 and a metal spring 23 are disposed and supported by a holder made of metal or plastic in the portion 25, and the roller 24 is biased and supported in one direction by the force of the metal spring 23. Then, when the driving force is transmitted, the roller 24 is pushed by the metal spring 23 and advances to the engagement position of the cam surface 22, the outer ring 21 and the inner ring 26 rotate together, and the roller 2 rotates when idling.
4 overcomes the urging force of the metal spring 23 and moves away from the engagement position of the cam surface 22, so that the outer ring 21 idles with respect to the inner ring 26.

(Problems to be Solved by the Invention) In recent years, with the widespread use of home video tape recorders, car-mounted audio tape recorders, and the like, the demand for one-way clutches used as drive mechanisms for these audiovisual devices has increased sharply. Of course, low cost products are required.

However, since the one-way clutch used for the drive mechanism of the audiovisual equipment is relatively small, the conventional product using the metal spring, including the retainer, has become difficult to manufacture.

Further, a physical resistance of the metal spring is an unavoidable drawback in its structure. Various shapes and structures of the retainer and the metal spring have been proposed in order to reduce the physical resistance of the metal spring, but none of them have a remarkable effect and the structure is complicated. However, because it uses a special material, it is a high-cost product that does not match the effect.

That is, due to the complicated assembly process and processing process, the product is inevitably high cost.

The present applicant has proposed a technique similar to the present invention as Japanese Patent Application No. 61-71950 (Japanese Patent Application Laid-Open No. 62-22872) in order to address the above-mentioned problems. By further developing this, it is not to provide a one-way clutch that has a small physical resistance and is easy to assemble, which is optimal for parts that transmit low torque, such as the drive mechanism of audiovisual equipment. .

(Means for Solving Problems) Therefore, the one-way clutch of the present invention includes an inner ring rotatably provided in the circumferential direction, rollers arranged at a predetermined interval on the outer circumference of the inner ring, and an outer circumference of the inner ring. A one-way clutch that is rotatably provided and that includes an outer ring that meshes with the roller and rotates integrally with the inner ring when the inner ring rotates in one direction. The protrusions formed of a magnetic material that extend radially inward and are arranged between the rollers that are adjacent to each other in the circumferential direction are integrally formed, and the rollers are located at the meshing position on one end surface of the protrusions in the outer ring circumferential direction. A suction surface for sucking is formed, and a relief surface is formed at the other end surface of the convex portion in the outer ring circumferential direction, which is inclined in the space direction of the inner ring as it goes radially outward of the outer ring.

In other words, the convex portion integrally formed on the inner circumference of the outer ring is magnetized to cause the convex portion to function as the metal spring in the conventional product, and the magnetic force of the convex portion is effective only in one direction of the roller. It is characterized in that it is adapted to act on.

(Operation) According to the one-way clutch of the present invention, when the driving force of the inner ring is transmitted, the roller is attracted to the suction surface of the convex portion of the outer ring and instantly meshes with the outer ring by the technical means as described above. Rotate together.

During idling, the reverse rotation torque of the inner ring causes the roller to overcome the magnetic attraction of the attraction surface, move away from the meshing position of the outer ring to the relief surface side, and the inner ring idles with respect to the outer ring.

(Example) Hereinafter, the Example of this invention is described based on drawing.

A first embodiment of the present invention will be described with reference to FIG. 1 and FIG. 2. Reference numeral 1 is an outer ring, and a plurality of cam surfaces 2 are formed on the inner peripheral surface thereof, and between the cam surfaces 2. Has a convex portion 3 extending inward in the radial direction. The cam surface 2 and the convex portion 3 are integrally molded alternately at equal intervals in the circumferential direction of the outer ring 1.

Reference numeral 4 denotes a roller, which is inserted and supported in a space portion 5 formed by the cam surface 2 and the convex portion 3.

An inner ring 6 is slidably supported on the circular arc surface of the convex portion 3 and is rotatable in the circumferential direction.

The outer ring 1, the cam surface 2 and the convex portion 3 are integrally formed by a plastic magnet, and only the convex portion 3 is magnetized.
Therefore, a suction surface 3A by magnetic force is formed on one end surface in the circumferential direction of the convex portion 3 in FIG.

On the other hand, on the other end surface of the convex portion 3 in the circumferential direction, a relief surface 3B is formed which is inclined in the idling direction of the inner ring 6 (the direction opposite to the arrow A in FIG. 2) as it goes radially outward of the outer ring 1. Relief surface 3B
Is a convex portion 3 that acts on the roller 4 from the side opposite to the suction surface 3A.
Plays a role of reducing the influence of the magnetism and increasing the responsiveness when the outer ring 1 is driven. Further, the protrusion 3C formed at the tip of the relief surface 3B makes it difficult for the roller 4 to fall out of the cavity 5 during the assembly of the one-way clutch, and improves the workability during assembly.

When the convex portion 3 is magnetized, for example, the tip of the magnetizing yoke may be inserted into the hollow portion 5 and the convex portion 3 may be sandwiched to perform the magnetization. This is because the magnetized portion of the magnetized yoke can be inserted into the cavity 5 relatively easily even if the outer ring 1 is relatively small.

Then, when the inner ring 6 tries to rotate in the direction of arrow A in FIG. 2 with the outer ring 1 as the driven side and the inner ring 6 as the driving side, the roller 4 already attracted by the convex portion 3 becomes the solid line in FIG. At the meshing position shown, the roller 4 instantly meshes with the peripheral surface of the inner ring 6 and the cam surface 2, and the outer ring 1, the inner ring 6 and the roller 4 rotate integrally.

When the inner ring 6 rotates in the direction opposite to the arrow A, the roller 4 overcomes the biasing force of the suction surface 3A by the reverse rotation torque of the inner ring 6 and moves to the position shown by the chain double-dashed line in FIG. The inner ring 6 runs idle with respect to the outer ring 1.

Here, when the roller 4 moves to the position shown by the alternate long and two short dashes line in FIG. 2, the clearance surface 3B keeps a predetermined distance from the peripheral surface of the roller 4 and is unlikely to exert a magnetic influence on the roller 4.
Therefore, even if the inner ring 6 rotates in the direction of arrow A in FIG. 2 from this state, the roller 4 can move to the meshing position shown by the solid line in FIG. 2 with good responsiveness without being attracted to the relief surface 3B. .

Next, FIG. 3 shows a one-way clutch according to a second embodiment of the present invention.

The second embodiment is one in which the present invention is applied to a drive mechanism of an audiovisual device.

Reference numeral 8 denotes a casing, which is axially supported by the inner ring 6 via a bearing 7, and the rubber roller 9 is attached to the outer peripheral surface of the casing 8.
I am wearing. By joining and fixing the casing 8 and the outer ring 1, the rubber roller 9 and the outer ring 1 are configured to rotate integrally.

Although not shown, convex portions having a suction surface and a relief surface are formed at equal intervals on the inner circumference of the outer ring 1.

Since the other construction is substantially the same as that of the first embodiment, the same components are designated by the same reference numerals and the description thereof will be omitted.

When the inner ring 6 rotates in a predetermined direction, the roller 4 meshes with the outer ring 1 to rotate the casing 8 and the rubber roller 9. When the inner ring 6 rotates in the opposite direction, the rollers 4 are disengaged from each other, and the inner ring 6 idles with respect to the outer ring 1, the casing 8 and the rubber roller 9.

According to the second embodiment, since the physical resistance of the inner ring 6 and the outer ring 1 during rotation is small, it is possible to realize a high-performance drive mechanism. Also, the number of parts is relatively small,
Assembly is also easy.

In the first embodiment, the case where the number of rollers is 4 has been described, but the load during rotation may be further reduced by increasing the number of rollers and plating the cam surface.
Further, in the second embodiment, the rubber roller is a pulley,
It may be adapted to various places by changing to a sprocket or the like.

(Effects of the Invention) As described above, according to the one-way clutch of the present invention, since the convex portion made of a magnetic material is integrally provided on the inner circumference of the outer ring, the roller is effectively biased by the magnetic force.
When the roller moves in that position, its movement is not hindered by physical resistance, and it can be reliably moved to the meshing position.

Therefore, when shifting from the idling state to the meshing state, the conventional product using the metal spring has a relatively large backlash due to variation in the movement of the roller due to the strength of the contact state between the roller and the metal spring. In the case of a one-way clutch, the roller is surely moved to the meshing position, so the backlash is extremely small.

Also, in manufacturing, not only the number of parts is reduced to 2 points compared with the conventional product, but the number of assembling steps is reduced, and since no metal spring is used, physical resistance is eliminated and the diameter of the cam surface is reduced. Some dimensional error in the direction is well tolerated.

As described above, the present invention is a useful invention that has various functions superior to those of conventional products and can achieve various excellent effects such as cost reduction.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a one-way clutch according to the present invention, FIG. 2 is a front view thereof, FIG. 3 is a longitudinal sectional view showing a one-way clutch according to a second embodiment of the present invention, and FIG. 4 shows a conventional example. It is a front view. Code table 1 ... Outer ring, 2 ... Cam surface 3 ... Convex portion, 3A ... Suction surface 3B ... Relief surface, 4 ... Roller 5 ... Space portion, 6 ... Inner ring 7 ... Bearing, 8 ... … Casing 9 …… Rubber roller

Continuation of the front page (56) Bibliographic references Sho 53-61559 (JP, U) Japanese patent 52-28240 (JP, B2) Japanese public 37-26991 (JP, Y1)

Claims (1)

[Claims] 1. An inner ring rotatably provided in the circumferential direction, rollers arranged at a predetermined interval on the outer circumference of the inner ring, and rotatably provided on the outer circumference of the inner ring so that the inner ring rotates in one direction. A one-way clutch that includes an outer ring that meshes with the roller and rotates integrally with the inner ring, wherein the inner ring of the outer ring extends radially inward of the outer ring and is adjacent to the rollers in the circumferential direction. A convex portion made of a magnetic material disposed between the convex portions is integrally formed, and at one end surface of the convex portion in the outer ring circumferential direction, a suction surface for sucking the roller to the meshing position is formed. A one-way clutch, characterized in that a relief surface is formed on the other end surface in the direction of the outer ring that is inclined in the spatial direction of the inner ring as it goes radially outward of the outer ring.