JP2008175278A - One-way clutch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve creep resistance force while utilizing advantages of a shell type outer ring, in a one-way clutch using a shell type outer ring. <P>SOLUTION: In the one-way clutch, cam faces forming a certain wedge angle with a shaft 12 are provided at predetermined intervals in a circumferential direction on a shell type outer ring 11 inner diameter face, a retainer 15 having a pocket corresponding to each cam face is positioned and fit on the outer ring 11 inner diameter face, and a roller 16 and a spring 17 energizing the roller 16 in a narrowing direction of the wedge angle are housed in the pocket. Detent protruding parts 19 are formed by bending a required number of protruding pieces axially protruding from one end of the outer ring 11 back onto an outer ring 11 outer diameter face. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a one-way clutch used in an office machine or the like.

  An outer ring of a one-way clutch that is formed into a cylindrical shape by deep drawing a sheet of steel is called a shell-type outer ring. A one-way clutch that uses a shell-shaped outer ring has a cross-sectional height that is equal to the torque capacity. Since it has advantages such as low cost and low cost, it has been conventionally used in the field of office machines and the like (see FIG. 6 of Patent Document 1 and its description).

  The one-way clutch using a shell-shaped outer ring is attached to the mating part (usually the housing of various devices) by press-fitting into the mounting hole provided in the mating part. When the mating part is made of resin, the tightening force is insufficient, and there is a possibility of slipping between the outer ring and the mating part due to the transmission torque at the time of locking. For this reason, in the one-way clutch disclosed in Patent Document 1, means for forming an axial detent ridge on the outer diameter surface of the outer ring corresponding to the cam surface of the inner diameter surface is employed. Yes.

  However, in this case, in order to increase the effect of detent (that is, to increase the creep resistance), if the height of the ridge is increased, the cam surface becomes deeper, and the diameter of the roller accordingly increases. There is a disadvantage that the number of rollers needs to be increased and the number of rollers decreases.

In order to solve this problem, in the invention of Patent Document 1, in order to increase the creep resistance without reducing the number of rollers, a protrusion for preventing rotation is formed on the outer diameter surface by drawing the steel pipe. The outer ring is made. The outer ring manufactured in this way can prevent the occurrence of slippage due to the presence of the protrusion having a high outer diameter surface even if the counterpart part is made of resin.
JP 2000-213566 (paragraphs 0003 to 0005, FIG. 6)

  However, as described above, the outer ring made by processing the metal tube requires man-hours such as drawing and cutting the metal tube in the production of the outer ring. In comparison, there is a problem of high cost.

  Accordingly, an object of the present invention is to provide a one-way clutch having a reliable detent function while taking advantage of the shell-type outer ring.

  In order to solve the above problems, the one-way clutch according to the present invention forms a constant wedge angle θ between the shaft 12 and the inner surface of the shell-shaped outer ring 11 as shown in FIGS. Cam surfaces 13 are provided at predetermined intervals in the circumferential direction, and cages 15 having pockets 14 corresponding to the respective cam surfaces 13 are positioned and fitted on the inner diameter surface of the outer ring 11, and are fitted into the pockets 14. A one-way clutch in which a roller 16 and a presser spring 17 that energizes the roller 16 in the narrow direction of the wedge angle θ is housed is a basic configuration.

  In the one-way clutch, when a required number of protruding pieces 22 protruding in the axial direction at one end of the outer ring 11 are folded back to the outer diameter surface of the outer ring 11, a rotation-preventing protrusion is formed on the outer diameter surface. 19 is formed.

  The one-way clutch configured as described above is fitted to the outer diameter surface of the shaft 12 of the apparatus, and the outer ring 11 is press-fitted into the mounting hole 29 (see FIG. 2) of the counterpart component 20 such as the housing. The attachment hole 29 is formed with a recess 33 corresponding to the detent projection 19. As shown by the arrow a, the shaft 12 idles with respect to the outer ring 11 when the shaft 12 rotates relative to the enlargement direction of the wedge angle θ and is locked when the shaft 12 rotates in the opposite direction.

  Since the one-way clutch according to the present invention is as described above, the anti-rotation projection 19 having the thickness of the material steel plate that forms the outer ring is formed on the outer diameter surface of the shell-shaped outer ring in the mounting hole 29 of the mating part. Since they are meshed in the rotational direction, slipping between the outer ring 11 and the counterpart component is prevented even when torque at the time of locking is transmitted. Further, since the shell-shaped outer ring 11 manufactured by press working is used, compared with the case using the outer ring manufactured by drawing a metal tube, there is an advantage that the cost is low.

  Hereinafter, embodiments of the one-way clutch according to the present invention will be described.

  The one-way clutch of the embodiment shown in the accompanying drawings corresponds to the shell-shaped outer ring 11, the required number of rollers 16, the cage 15 of each roller 16, and each roller 16, as shown in FIGS. 1 and 2. It consists of a holding spring 17 and is fitted into the outer diameter surface of the shaft 12 for use.

  The outer ring 11 is formed by deep drawing a single steel plate 21 (see FIG. 4A). The processing procedure will be described next.

    The material steel plate 21 is formed by forming a required number of protruding pieces 22 of the same length radially on the periphery of the disc. Deep drawing is applied around the center O of the material steel plate 21 to produce a cup-shaped molded product 23 (see FIG. 4B). The protruding pieces 22 are arranged so as to protrude outward over the entire circumference of the open end of the molded product 23. Next, the shaft hole 24 is formed by punching in the center of the closed surface of the molded product 23, thereby forming an inward collar-shaped retaining portion 25 around the shaft hole 24 (FIG. 4C). reference).

  Next, a required number of arc-shaped cam surfaces 13 including a circumferentially inclined portion on the inner diameter surface of the molded product 23 are formed in a range of a required length in the axial direction, and the cam surface 13 is further formed. A retaining groove 26 is formed over the entire circumference near the open end of the molded product 23 in the range. Thereafter, the outer ring 11 in which the anti-rotation protrusion 19 having a height equal to the thickness of the raw steel plate 21 is formed on the outer diameter surface by folding the protruding piece 22 back to the outer diameter surface of the body 23 of the molded product 23. Is obtained (see FIG. 4D). The folding length of the protruding piece 22 is shown to the extent that the tip reaches the end of the cam surface 13 in the illustrated case, but is appropriately selected so as to be longer or shorter than that.

  The cage 15 inserted into the outer ring 11 has a cage shape as shown in FIG. 3, and a column portion 28 is provided between the pair of left and right ring portions 27, 27 ′ at a constant interval in the circumferential direction. It is a resin molded product provided integrally, and the pocket 14 is formed between the pillar portions 28. In addition, a gentle convex portion 31 is engaged with the outer diameter surface of each of the ring portions 27 and 27 ′ for each pocket 14. This convex part 31 is formed in the shape fitted to the circular arc surface of the front cam surface 13, and when each convex part 31 fits to the cam surface 13, the positioning of the holder | retainer 15 in the circumferential direction is made. Further, a circumferential rib 32 is formed on the outer diameter surface of the one ring portion 27, and the rib 32 is fitted into the retaining groove 26, whereby the cage 15 is positioned in the axial direction.

  Rollers 16 are accommodated in the pockets 14 of the cage 15, and the rollers 16 fit into the cam surface 13. A pressing spring 17 is attached to each column portion 28, and its elastic portion contacts the roller 16, and the roller 16 is urged in the narrow direction of the wedge angle θ to stabilize its posture.

  The one-way clutch of the embodiment is as described above, and is press-fitted into the mounting hole 29 (see FIG. 2) of the counterpart component 20 when used. A concave portion 33 corresponding to the anti-rotation protrusion 19 of the outer ring 11 is formed on the inner diameter surface of the mounting hole 29, and the anti-rotation protrusion 19 is fitted into the concave portion 33 to be engaged in the circumferential direction.

  As in the normal case, when the shaft 12 rotates in the direction of expansion of the wedge angle θ (see arrow a in FIG. 2), the one-way clutch moves as the roller 16 moves in the direction of expansion of the wedge angle θ. The shaft 12 idles and the transmission of torque to the counterpart component 20 is interrupted. When the roller 16 rotates in the opposite direction, the roller 16 is engaged with the narrow portion of the wedge angle θ, and is locked to transmit torque. At the time of torque transmission, the non-rotating projection 19 of the outer ring 11 meshes with the recess 33 of the counterpart component 20 to exert a large creep resistance and prevent the occurrence of slipping.

Sectional drawing in the use condition of the one way clutch of an Example FIG. 1 is an enlarged sectional view taken along line AA in FIG. Partial perspective view of the cage of the embodiment (A) Plan view of material steel plate of outer ring, (b) Cross section of molded product, (c) Cross section during processing of molded product, (d) Cross section of outer ring

Explanation of symbols

11 Outer ring 12 Shaft 13 Cam surface 14 Pot 15 Cage 16 Roller 17 Pressing spring 19 Non-rotating projection 20 Counterpart 21 Material steel plate 22 Extruding piece 23 Molded product 24 Shaft hole 25 Retaining portion 26 Retaining groove 27, 27 'Ring Part 28 column part 29 mounting hole 31 convex part 32 rib 33 concave part

Claims (1)

  Cam surfaces (13) that form a constant wedge angle θ between the inner diameter surface of the shell-shaped outer ring (11) and the shaft (12) are provided at predetermined intervals in the circumferential direction, and each cam surface (13) A cage (15) having a pocket (14) corresponding to the outer ring (11) is positioned and fitted on the inner surface of the outer ring (11), and the roller (16) and the roller (16) are inserted into the pocket (14) with the wedge angle. In the one-way clutch in which a holding spring (17) urging in the direction of narrowing θ is housed, a required number of protruding pieces (22) provided protruding in the axial direction at one end of the outer ring (11) are provided on the outer ring. (11) A one-way clutch characterized in that an anti-rotation protrusion (19) is formed on the outer diameter surface of the outer ring (11) by folding back to the outer diameter surface.

Images