One-way clutch

Abstract

Provided is a unidirectional clutch in which the size in the radial direction can be reduced, and which reduces the effort involved in assembly work. In a holder (3), a bonding part (3b) to which a to-be-engaged part (3e) is provided extends, from a base (3c) on the opposite side to the side on which each columnar part (3a) is provided in upright position, in a cylindrical shape surrounding a shaft (7), and the bonding part (3b) is disposed in a housing (2) alongside the outer circumference of an outer sleeve (4). The housing (2) has a storage part (2a) having an inner diameter covering respective outer circumferences of the holder (3) and the outer sleeve (4) at which the two are arranged side by side. An engaging part (2f) that engages with the to-be-engaged part (3e) in a center axial direction to transfer the rotation of the holder (3) to the housing (2), is formed on the inner circumference of the housing. On one end side of the storage part (2a), a restriction wall (2b) that restricts the movement of an inner unit (5) toward the one end side of the storage part (2a) is formed so as to face an end surface (3f) of the bonding part (3b). A cap (6) that restricts the inner unit (5) from coming off is fitted into an insertion opening (2c) that is open on the other end side of the storage part (2a).

Description

[Technical field]

[0001] The present invention relates to a one-way clutch in which rotation of a shaft in one direction is transmitted to a housing. [Background technology]

[0002] A conventional one-way clutch of this type is disclosed in, for example, Patent Document 1. This one-way clutch includes a ring-shaped member and a holding member in which a protruding column is inserted into the ring. The protruding columns are erected on the end face of the body of the holding member, which has an insertion hole into which the rotating shaft is inserted, so as to surround the insertion hole. A needle is held in a holding groove formed in a gap between the protruding columns. When the rotating shaft inserted into the insertion hole of the holding member rotates in a clockwise direction, the tightening state due to the engagement between the inner surface of the ring-shaped member and the outer circumferential surface of the needle is not strong, so the ring-shaped member and the rotating shaft can rotate relatively. When the rotating shaft rotates in a counterclockwise direction, the tightening state becomes strong, so the operating part attached to the ring-shaped member and the rotating shaft cannot rotate relatively, and torque can be transmitted between them.

[0003] The operating parts consist of an outer cylinder into which the one-way clutch is fitted and a torque transmission member formed integrally with the outer cylinder. The outer cylinder is attached to the outer periphery of the ring-shaped member so as to be rotatable integrally with the ring-shaped member by engaging ridges on the inner periphery of the outer cylinder with notches on the outer surface of the ring-shaped member.

[0004] Furthermore, as a conventional one-way clutch of this type, for example, one is disclosed in Patent Document 2. This one-way clutch is composed of a retainer that holds a torque transmission ring, an outer ring, rollers, and a biasing spring, and the retainer is housed inside the outer ring. During use, a shaft is inserted through the torque transmission ring and the outer ring, which are connected in the axial direction, and a pair of retaining rings that prevent the one-way clutch from coming off are fitted onto both ends of the one-way clutch on the outer circumference of the shaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-336797 [Patent Document 2] JP 2010-242889 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional one-way clutch disclosed in Patent Document 1, an engaging protrusion provided on the inner circumference of the outer cylinder engages with a notch provided on the outer circumference of the ring-shaped member in the radial direction of the one-way clutch, so that the outer cylinder is attached to the outer circumference of the ring-shaped member. Therefore, if the radial thickness of the ring-shaped member is reduced to reduce the radial size of the one-way clutch, the ring-shaped member is subjected to a load from the needle, which may cause the ring-shaped member to break, and there is a limit to how much the radial size of the one-way clutch can be reduced.

[0007] Furthermore, the one-way clutch disclosed in the above-mentioned conventional Patent Document 2 can be made compact in the radial direction by connecting the torque transmission ring and the outer ring in the axial direction. However, in the one-way clutch disclosed in the above-mentioned conventional Patent Document 2, a pair of retaining rings must be fitted onto the shaft at both ends of the one-way clutch to prevent the torque transmission ring and the outer ring from coming off the shaft, which makes the assembly process time-consuming. [Means for solving the problem]

[0008] The present invention has been made to solve such problems, A circumferential direction surrounding a shaft inserted into an inner diameter portion formed in a base In The pillars are spaced at regular intervals. On a pedestal A plurality of upright retainers; a hollow cylindrical outer sleeve having an inner periphery surrounding the side periphery of each of the columnar portions erected on the base; a cylindrical rolling element that is rollably held in a pocket that is sandwiched between an inner wall surface of the outer sleeve and an outer periphery of the shaft between adjacent columnar portions; an elastic member that biases the rolling element toward one of the adjacent columnar portions in the pocket; A one-way clutch including a housing that covers an outer periphery of a cage and an outer sleeve and transmits one-way rotation of a shaft depending on a rolling position of a rolling element in a pocket portion, The retainer is formed on a base on the side opposite to the side on which each columnar portion is erected, and a coupling portion provided with an engaged portion is formed in a cylindrical shape surrounding the axis, and the outer periphery of the coupling portion is aligned with the outer periphery of the outer sleeve and is disposed within the housing coaxially with the outer sleeve, The housing has an inner diameter storage section that covers the outer periphery of each of the arranged retainers and outer sleeves, an engaging section is formed on the inner circumference that engages with the engaged section in the axial direction to transmit rotation of the retainer to the housing, a regulating wall is formed on one end of the storage section facing the end face of the connecting section to regulate the movement of the retainer and outer sleeve toward one end of the storage section in the axial direction, and a cap is fitted into an insertion opening for the retainer and outer sleeve into the storage section, which opens to the other end of the storage section in the axial direction, to regulate the deviation of the retainer and outer sleeve from the insertion opening.

[0009] According to this configuration, the retainer and the outer sleeve are stored in a housing storage section having an inner diameter that covers the outer peripheries of the respective arranged retainers. The housing and the retainer are arranged such that an engaging portion formed on the inner periphery of the housing engages with an engaged portion provided on the coupling portion in the axial direction of the housing, thereby transmitting the rotation of the retainer to the housing. Therefore, unlike the conventional one-way clutch disclosed in Patent Document 1 in which the inner periphery of the housing and the outer periphery of the outer sleeve engage in the radial direction of the one-way clutch and there is a limit to reducing the radial thickness of the outer sleeve, there is no need to ensure an engagement space between the engaging portion and the engaged portion in the radial direction of the one-way clutch, and it is possible to reduce the radial size of the one-way clutch.

[0010] In addition, the retainer and outer sleeve stored in the storage section of the housing are restricted from moving toward one end of the storage section in the axial direction by a restricting wall formed on one end of the storage section. In addition, a cap is fitted into an insertion opening for the retainer and outer sleeve into the storage section, which opens on the other end of the storage section in the axial direction, thereby restricting the retainer and outer sleeve from departing from the insertion opening. This eliminates the need for assembly work in which a pair of retaining rings are fitted onto the shaft to prevent the retainer and outer sleeve inserted onto the shaft from coming off, as in the conventional one-way clutch disclosed in Patent Document 2, and reduces the labor required for assembly.

[0011] The present invention is also characterized in that the engaged portions are formed by cutting away a predetermined length from an end face of the coupling portion in the axial direction at a plurality of locations in the cage.

[0012] According to this configuration, the coupling portion is cut out at a predetermined length from the end face of the coupling portion in the axial direction of the housing at multiple locations to form the engaged portion, so that the coupling portion has flexibility in a direction intersecting with the axial direction. Therefore, when bending stress or torsional stress is applied to the housing, the coupling portion elastically deforms due to the stress and absorbs the stress, preventing the rolling elements from skewing or slipping, and preventing poor engagement of the rolling elements when the one-way clutch is locked and poor rolling when the one-way clutch is in an idling operation.

[0013] Furthermore, the present invention is characterized in that in the retainer, the length by which the connecting portion extends from the end face of the base on which the columnar portion is erected is set longer than a specified length of the engaged portion which is formed by being cut out to a specified length in the axial direction.

[0014] According to this configuration, the strength of the joint portion of the cage can be maintained, and the engaged portion formed at the joint portion firmly engages with the engaging portion formed on the inner periphery of the housing, so that the rotation of the cage is reliably transmitted to the housing. Also, the cage can be reliably positioned relative to the housing.

[0015] The present invention is also characterized in that the engaged portion and the engaging portion are set to lengths that generate a gap between the end face of the coupling portion and the regulating wall when they are engaged with each other.

[0016] According to this configuration, when the engaged portion and the engaging portion are engaged, the end face of the coupling portion and the restricting wall do not come into contact with each other, so that damage to each component caused by the contact can be prevented.

[0017] Furthermore, the present invention is characterized in that the retainer is fixed to the outer sleeve by the rectangular inner wall surface of the outer sleeve abutting against the square column-shaped side periphery at the rising portion of each columnar portion from the base and being pressed into the outer sleeve.

[0018] If there is a gap between the fixed parts of the cage and the outer sleeve, and the relative rotational positions of the cage and the outer sleeve are misaligned, and the positional relationship between the columnar parts of the cage and the inner wall surface of the outer sleeve changes, the rolling elements stored in the pockets may be obstructed by the columnar parts of the cage, hindering the locking action in which the rolling elements are engaged between the inner wall surface of the outer sleeve and the outer periphery of the shaft. However, according to this configuration, the periphery of the rectangular columnar riser side of each columnar part of the cage abuts against the rectangular inner wall surface of the outer sleeve and is pressed into the outer sleeve, so that no gap is generated between the fixed parts of the cage and the outer sleeve, and no misalignment occurs between the relative rotational positions of the cage and the outer sleeve. Therefore, the positional relationship between the columnar parts of the cage and the inner wall surface of the outer sleeve is maintained in the initial setting position and does not change, and the locking action in which the rolling elements are engaged between the inner wall surface of the outer sleeve and the outer periphery of the shaft is not hindered by the columnar parts of the cage. As a result, rotation of the shaft in one direction is reliably transmitted to the housing by a locking action in which the rolling elements are engaged between the inner wall surface of the outer sleeve and the outer periphery of the shaft.

[0019] The present invention is also characterized in that the cap has an inner diameter portion through which the shaft is inserted, and the housing has an inner diameter portion through which the shaft is inserted on the side opposite to the side of the storage portion where the cap is fitted.

[0020] According to this configuration, the shaft is inserted through an inner diameter portion formed in the base of the retainer, an inner diameter portion provided in the housing on the side opposite to the side where the cap of the storage portion is provided, and an inner diameter portion provided in the cap, and thus the shaft rotates stably without wobbling.

[0021] The present invention is also characterized in that the outer peripheral surface of the outer sleeve has a shape in which arcuate surfaces and flat surfaces are arranged alternately.

[0022] According to this configuration, the outer sleeve can be easily positioned during automatic assembly of the one-way clutch. Effect of the Invention

[0023] According to the present invention, it is possible to provide a one-way clutch that can be made compact in radial size and reduces the labor required for assembly. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1A is a front view of a one-way clutch according to an embodiment of the present invention, and FIG. 1B is a perspective view of a cutaway cross section of the one-way clutch. [Diagram 2] FIG. 2(a) is a front view of a housing that constitutes the one-way clutch shown in FIG. 1, and FIG. 2(b) is a perspective view of a cross section of the housing cut away. [Diagram 3] FIG. 2(a) is a perspective view of the inner unit taken out of the housing shown in FIG. 1(b), and FIG. 2(b) is a perspective view of the inner unit with an outer sleeve removed. [Figure 4] 3(a) is a perspective view of a retainer constituting the inner unit shown in FIG. 3(a) as viewed from the columnar portion side, and FIG. 3(b) is a perspective view of the retainer as viewed from the joint portion side. [Diagram 5] 4(b) from a different angle, and FIG. 5(b) is a perspective view of a cross section of the retainer shown in FIG. 4(a). [Figure 6]FIG. 4(a) is a perspective view of an outer sleeve that constitutes the inner unit shown in FIG. 3(a), and FIG. [Figure 7] FIG. 4 is a front view of the internal unit shown in FIG. [Figure 8] FIG. 2(a) is a front view of a cap constituting the one-way clutch shown in FIG. 1, and FIG. 2(b) is a perspective view of a cross section of the cap cut away. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Next, an embodiment of a one-way clutch according to the present invention will be described. In the following, the same or corresponding parts in each drawing are denoted by the same reference numerals.

[0026] Fig. 1(a) is a front view of a one-way clutch 1 according to an embodiment of the present invention, and Fig. 1(b) is a perspective view of a cross section of the one-way clutch 1 taken along line Ib-Ib. The one-way clutch 1 is configured such that an inner unit 5 consisting of a retainer 3 and an outer sleeve 4 is housed in a housing 2, and a cap 6 is fitted onto an insertion opening of the inner unit 5 into the housing 2. The one-way clutch 1 transmits unidirectional rotation of a shaft 7 (see Fig. 7), which will be described later, that is inserted into the inner unit 5, to the housing 2. The housing 2 has a rubber roller wound around its outer periphery, or has gears or the like formed on its outer periphery, and only the unidirectional rotation of the shaft 7 is transmitted to these rubber rollers, gears, or the like by the one-way clutch 1.

[0027] FIG. 2(a) shows a front view of the housing 2, and FIG. 2(b) shows a perspective view of a cross section cut along line IIb-IIb. The housing 2 is molded into a hollow cylindrical shape using resin, metal, or the like, and inside the housing 2, spaces with different inner diameters are formed side by side in the axial direction. The space with a large inner diameter in which the internal unit 5 is stored constitutes the storage section 2a of the internal unit 5. The storage section 2a has an inner diameter that covers the outer circumferences of the retainer 3 and the outer sleeve 4, and covers the outer circumferences of the retainer 3 and the outer sleeve 4. At one end side of the storage section 2a in the axial direction of the housing 2, the inner diameter of the housing 2 is reduced to form a regulating wall 2b. At an insertion opening 2c into the storage section 2a of the internal unit 5, which opens at the other end side of the storage section 2a in the axial direction of the housing 2, a fitting groove 2d into which the cap 6 fits is formed in an annular shape along its inner circumference. The restricting wall 2b restricts the inner unit 5 from moving toward one end side (thrust direction) of the storage portion 2a, and the cap 6 fitted into the insertion opening 2c restricts the inner unit 5 from escaping from the insertion opening 2c.

[0028] The housing 2 also has an inner diameter portion 2e, the inner diameter of which is smaller than the inner diameter of the storage portion 2a, on the side opposite to the side where the cap 6 of the storage portion 2a is fitted. The inner diameter of the inner diameter portion 2e is formed to be one step smaller than each space formed on both sides of the inner diameter portion 2e, the inner diameter of which is smaller than the inner diameter of the storage portion 2a. The shaft 7 of the housing 2 is inserted coaxially into the inner diameter portion 2e, and contacts the shaft 7 only at the inner diameter portion 2e. The inner circumference of the housing 2 is also formed with three engagement portions 2f that engage with the retainer 3, extending in the axial direction. In this embodiment, each engagement portion 2f extends from the regulating wall 2b toward the insertion opening 2c on the inner circumference of the storage portion 2a by a length L1.

[0029] Fig. 3(a) is a perspective view of the inner unit 5 removed from the housing 2, and Fig. 3(b) is a perspective view of the inner unit 5 with the outer sleeve 4 removed. Fig. 4(a) is a perspective view of the retainer 3 seen from the columnar portion 3a side, and Fig. 4(b) is a perspective view of the retainer 3 seen from the connecting portion 3b side. Fig. 5(a) is a perspective view of the connecting portion 3b seen from a different angle, and Fig. 5(b) is a perspective view of the retainer 3 cut in the axial direction.

[0030] The retainer 3 is molded from resin, metal, or the like, and the shaft 7 is inserted into the inner diameter portion 3d formed by opening at the center of the seat 3c as shown in FIG. 5(b). A plurality of columnar portions 3a are erected at a predetermined interval in the circumferential direction surrounding the shaft 7 inserted into the inner diameter portion 3d on the seat 3c. In addition, on the seat 3c on the side opposite to the side on which the columnar portions 3a are erected, an engaged portion 3e and three coupling portions 3b are formed to extend in a cylindrical shape surrounding the inserted shaft 7. In this embodiment, the engaged portion 3e is formed by cutting the coupling portion 3b at three points in the axial direction of the housing 2 from the end face 3f of the coupling portion 3b by a predetermined length L2 (see FIG. 4(a)). 5(a), the connecting portion 3b is divided in the circumferential direction by the engaged portions 3e into islands that are formed in a substantially C-shape when the cage 3 is viewed from the connecting portion 3b side, forming buffer portions that buffer the stress applied to the connecting portion 3b. The engaging portions 2f of the housing 2 engage with the engaged portions 3e in the axial direction, and the rotation of the cage 3 is transmitted.

[0031] In the retainer 3, when the engaged portion 3e and the engaging portion 2f are engaged with each other, a gap s (see FIG. 1(b)) is generated between the end face 3f of the connecting portion 3b and the regulating wall 2b, and the length L1 of each engaging portion 2f is set to be equal to or greater than the length L2 of the engaged portion 3e so that the end face 3f of the connecting portion 3b faces the regulating wall 2b (L1≧L2). In addition, the length L3 of the connecting portion 3b extending from the end face 3g (see FIG. 4(a)) of the base 3c on which each columnar portion 3a stands is set to be longer than the predetermined length L2 of the engaged portion 3e (L3>L2). In addition, the length L3 of the connecting portion 3b extending from the end face 3g of the base 3c on which each columnar portion 3a stands is set to be equal to or greater than the length L4 of each columnar portion 3a protruding from the end face 3g (L3≧L4).

[0032] The outer sleeve 4 is shown in a perspective view in FIG. 6(a) and in a front view in FIG. 6(b), and has a hollow cylindrical shape in which the inner periphery surrounds the side periphery of each columnar portion 3a erected on the base 3c of the cage 3. This outer sleeve 4 is molded from resin, metal, or the like. The outer periphery of the outer sleeve 4 has a shape in which arc surfaces 4a and flat surfaces 4b are alternately arranged as shown in FIG. 6(b). In addition, the inner periphery of the outer sleeve 4 is formed with wedge surfaces 4c whose radial position decreases in the clockwise direction in FIG. The outer sleeve 4 is attached to the cage 3 surrounding the side periphery of each columnar portion 3a of the cage 3, and constitutes an inner unit 5 together with the cage 3 as shown in FIG. 3(a). In this embodiment, the retainer 3 is fixed to the outer sleeve 4 by having the rectangular inner wall surface 4d on the inner circumference of the outer sleeve 4, which is attached to the retainer 3, abut against the rectangular column-shaped side periphery of the rising portion 3h of each columnar portion 3a rising from the base 3c, and being pressed into the outer sleeve 4.

[0033] The outer sleeve 4 surrounds the side periphery of each columnar portion 3a of the cage 3, and thus a pocket portion 5a is formed in the inner unit 5 as shown in FIG. 3(a) and FIG. 7. FIG. 7 is a front view of the inner unit 5. The pocket portion 5a is formed between the adjacent columnar portions 3a, 3a, sandwiched between the inner wall surface of the outer sleeve 4 and the outer periphery of the shaft 7 shown by the broken line in the same figure. The pocket portion 5a contains a cylindrical steel needle roller 8 and a steel spring 9 that is substantially S-shaped in side view as shown in FIG. 3(b). The needle roller 8 constitutes a rolling body that is held in the pocket portion 5a so as to be freely rollable, and the spring 9 constitutes an elastic member that biases the needle roller 8 toward one of the adjacent columnar portions 3a, 3a in the pocket portion 5a. Incidentally, this elastic member does not have to be separate from the cage 3, but may be formed integrally with the cage 3 on the side surface of the columnar portion 3a facing the pocket portion 5a of the cage 3.

[0034] The inner unit 5 (see FIG. 3(a)), in which the outer sleeve 4 is attached to the retainer 3 surrounding each columnar portion 3a, is inserted into the storage portion 2a inside the housing 2 through the insertion opening 2c of the housing 2. At this time, the retainer 3 is arranged in the housing 2 coaxially with the outer sleeve 4, with the outer periphery of the joint portion 3b aligned with the outer periphery of the outer sleeve 4, as shown in FIG. 1(b). After that, the insertion opening 2c of the housing 2 is covered with a cap 6 to close the insertion opening 2c. FIG. 8(a) shows a front view of the cap 6, and FIG. 8(b) shows a perspective view of a cross section cut along line VIIIb-VIIIb. The cap 6 is molded from resin, metal, or the like into a hollow cylinder having an inner diameter portion 6a on the inner periphery through which the shaft 7 is inserted, and a fitting protrusion 6b is formed on the outer periphery so as to protrude annularly in the circumferential direction. When the cap 6 is placed on the insertion opening 2c, the fitting protrusion 6b fits into a fitting groove 2d formed in the insertion opening 2c of the housing 2, and the cap 6 is fixed to the insertion opening 2c.

[0035] In the one-way clutch 1 configured as above, the rotation of the shaft 7 is transmitted in one direction to the housing 2 depending on the rolling position of the needle rollers 8 in the pocket portion 5a. That is, when the shaft 7 rotates in the clockwise direction A in which the radial position of the wedge surface 4c shown in Fig. 7 becomes smaller, the needle rollers 8 in contact with the outer periphery of the shaft 7 also roll in the same direction and become engaged between the wedge surface 4c and the outer periphery of the shaft 7. As a result, the needle rollers 8 enter a locked state, and torque is transmitted from the shaft 7 to the housing 2, and the rotation of the shaft 7 in the clockwise direction A is transmitted to the housing 2, causing the housing 2 to rotate in the same direction.

[0036] On the other hand, when the shaft 7 rotates in the counterclockwise direction B, which increases the radial position of the wedge surface 4c, the needle rollers 8 in contact with the outer periphery of the shaft 7 also roll in the same direction, and the needle rollers 8 enter a free state in which they are not constrained by the wedge surface 4c and the outer periphery of the shaft 7. As a result, no torque is transmitted from the shaft 7 to the housing 2, and the rotation of the shaft 7 in the counterclockwise direction B is not transmitted to the housing 2, which does not rotate. As a result, only the rotation of the shaft 7 in the clockwise direction A is transmitted to the housing 2, depending on the rolling position of the needle rollers 8 in the pocket portion 5a.

[0037] According to the one-way clutch 1 of this embodiment, the retainer 3 and the outer sleeve 4 are stored in the storage section 2a of the housing 2, which has an inner diameter covering the outer peripheries of the retainer 3 and the outer sleeve 4 arranged side by side, as described above. The housing 2 and the retainer 3 are arranged such that an engaging section 2f formed on the inner periphery of the housing 2 engages with an engaged section 3e provided on the coupling section 3b in the axial direction of the housing 2, so that the rotation of the retainer 3 is transmitted to the housing 2. Therefore, unlike the conventional one-way clutch disclosed in Patent Document 1, in which the inner periphery of the housing and the outer periphery of the outer sleeve engage in the radial direction of the one-way clutch and there is a limit to reducing the radial thickness of the outer sleeve, there is no need to ensure an engagement space between the engaging section 2f and the engaged section 3e in the radial direction of the one-way clutch 1, and it is possible to reduce the radial size of the one-way clutch 1.

[0038] In addition, the internal unit 5 stored in the storage section 2a of the housing 2 is restricted from moving toward one end of the storage section 2a by a restricting wall 2b formed on one end of the storage section 2a. In addition, a cap 6 is fitted into an insertion opening 2c of the internal unit 5 into the storage section 2a, which opens on the other end of the storage section 2a, thereby restricting the internal unit 5 from escaping from the insertion opening 2c. Therefore, in order to prevent the internal unit 5 inserted into the shaft 7 from coming off, it is no longer necessary to perform an assembly operation of fitting a pair of retaining rings onto the shaft, as in the conventional one-way clutch disclosed in Patent Document 2, and the labor required for assembly is reduced.

[0039] Furthermore, according to the one-way clutch 1 of this embodiment, the coupling portion 3b is cut out at a plurality of locations in the axial direction from the end face 3f of the coupling portion 3b by a predetermined length L2 to form the engaged portion 3e, and the aforementioned buffer portion is configured, so that the coupling portion 3b has flexibility in a direction intersecting with the axial direction of the housing 2. For this reason, when bending stress or torsional stress is applied to the housing 2, the coupling portion 3b elastically deforms due to the stress and absorbs the stress, thereby preventing the needle rollers 8 from skewing or slipping, and preventing poor engagement of the needle rollers 8 during a locking operation of the one-way clutch 1 and poor rolling during an idling operation.

[0040] Furthermore, according to the one-way clutch 1 of this embodiment, the length L3 of the connecting portion 3b is formed longer than the length L2 of the engaged portion 3e (L3>L2), so that the component strength of the connecting portion 3b of the retainer 3 can be maintained. Therefore, the engaged portion 3e formed in the connecting portion 3b firmly engages with the engaging portion 2f formed on the inner periphery of the housing 2, so that the rotation of the retainer 3 is reliably transmitted to the housing 2. Furthermore, the retainer 3 can be reliably positioned relative to the housing 2.

[0041] Furthermore, according to the one-way clutch 1 of this embodiment, when the engaged portion 3e and the engaging portion 2f are engaged with each other, a gap s is generated between the end face 3f of the joining portion 3b and the restricting wall 2b (L1≧L2), so that when the engaged portion 3e and the engaging portion 2f are engaged, the end face 3f of the joining portion 3b does not come into contact with the restricting wall 2b. Therefore, it is possible to prevent damage to each component caused by the end face 3f of the joining portion 3b coming into contact with the restricting wall 2b.

[0042] Furthermore, according to the one-way clutch 1 of this embodiment, the length L3 by which the connecting portion 3b extends from the end face 3g is set to be greater than or equal to the length L4 by which each columnar portion 3a protrudes from the end face 3g (L3≧L4), so that the rotation of the retainer 3 in the storage portion 2a is stabilized and the rotation is transmitted smoothly from the retainer 3 to the housing 2.

[0043] Furthermore, if there is a gap (backlash) between the fixed portions of the cage 3 and the outer sleeve 4, and the relative rotational positions of the cage 3 and the outer sleeve 4 are misaligned by the amount of backlash, the positional relationship between the columnar portion 3a of the cage 3 and the wedge surface 4c on the inner wall surface of the outer sleeve 4 changes. If the positional relationship between the columnar portion 3a and the wedge surface 4c changes, the needle rollers 8 housed in the pocket portion 5a may collide with and come into contact with the columnar portion 3a before coming into contact with the wedge surface 4c when transmitting the one-way rotation of the shaft 7 to the housing 2. In this case, the needle rollers 8 are obstructed by the columnar portion 3a, hindering the locking action of being engaged between the wedge surface 4c and the outer periphery of the shaft 7, and the one-way rotation of the shaft 7 is no longer transmitted to the housing 2.

[0044] However, according to the one-way clutch 1 of this embodiment, the side periphery of the rectangular column-shaped rising portion 3h of each columnar portion 3a abuts against the rectangular inner wall surface 4d of the outer sleeve 4, and the retainer 3 is press-fitted into the outer sleeve 4, so that no gap is generated between the fixed portions of the retainer 3 and the outer sleeve 4, and no deviation occurs in the relative rotational positions of the retainer 3 and the outer sleeve 4. Therefore, the positional relationship between the columnar portion 3a and the wedge surface 4c is maintained at the initial set position and does not change, and the locking action of the needle roller 8 being engaged between the wedge surface 4c and the outer periphery of the shaft 7 is not hindered by the columnar portion 3a. Therefore, the rotation of the shaft 7 in one direction is reliably transmitted to the housing 2 by the locking action of the needle roller 8 being engaged between the wedge surface 4c and the outer periphery of the shaft 7.

[0045] Furthermore, according to the one-way clutch 1 of this embodiment, the shaft 7 is inserted through the inner diameter portion 3d formed in the seat 3c of the retainer 3, the inner diameter portion 2e provided in the housing 2 on the side opposite to the side where the cap 6 of the storage portion 2a is provided, and the inner diameter portion 6a provided in the cap 6, and thus the rotation is supported. Therefore, the shaft 7 rotates stably without wobbling.

[0046] Furthermore, according to the one-way clutch 1 of this embodiment, the outer peripheral surface of the outer sleeve 4 has a shape in which the arc surfaces 4a and the flat surfaces 4b are arranged alternately, so that the positioning of the outer sleeve 4 can be easily performed during automatic assembly of the one-way clutch 1.

[0047] In the above embodiment, the engaging portion 2f is formed on the inner circumference of the storage portion 2a so as to protrude in the axial direction, and the engaged portion 3e is formed on the coupling portion 3b by being notched in the axial direction, so that the engaging portion 2f and the engaged portion 3e engage in the axial direction. However, on the contrary, the engaging portion 2f may be formed on the inner circumference of the housing 2 arranged next to the storage portion 2a so as to be notched in the axial direction of the housing 2, so that the engaged portion 3e extends from the end face 3f of the coupling portion 3b in the axial direction of the housing 2, so that the engaging portion 2f and the engaged portion 3e engage in the axial direction of the housing 2. With such a configuration, the same effects as those of the above embodiment can be achieved.

[0048] In addition, the buffer portion formed by the connecting portion 3b has been described as being formed by dividing the connecting portion 3b into C-shaped islands as shown in Fig. 5(a). However, the cylindrical connecting portion 3b may simply be divided in the circumferential direction by the connected portion 3e, and the arc-shaped walls may be erected on the base 3c at a predetermined interval. Even with such a configuration, the stress applied to the housing 2 is absorbed by the buffer portion, and the same effect as the above embodiment is achieved.

[0049] Further, the outer sleeve 4 has been described as having an outer circumferential surface in a shape in which the arcuate surfaces 4a and the flat surfaces 4b are alternately arranged, but it may simply be in a cylindrical shape. [Explanation of symbols]

[0050] 1...One-way clutch, 2...Housing, 2a...Storage section, 2b...Regulating wall, 2c...Insertion port, 2d...Fitting groove, 2e...Inner diameter portion of housing 2, 2f...Engagement portion, 3...Cage, 3a...Columnar portion, 3b...Connecting portion, 3c...Pedestal, 3d...Inner diameter portion of cage 3, 3e...Engaged portion, 3f...End face of connecting portion 3b, 3g...End face of pedestal 3c, 3h...Rising portion, 4...Outer sleeve, 4a...Circular surface, 4b...Flat surface, 4c...Wedge surface, 4d...Rectangular inner wall surface, 5...Inner unit, 5a...Pocket portion, 6...Cap, 6a...Inner diameter portion of cap 6, 6b...Fitting protrusion, 7...Shaft, 8...Needle roller (rolling body), 9...Spring (elastic member)

Claims

1. a cage having a plurality of columnar portions erected on the base at predetermined intervals in a circumferential direction surrounding a shaft that is inserted into an inner diameter portion formed in the base; a hollow cylindrical outer sleeve having an inner periphery surrounding a side periphery of each of the columnar portions erected on the base; a cylindrical rolling element that is rollably held in a pocket that is formed between the adjacent columnar portions and that is sandwiched between an inner wall surface of the outer sleeve and an outer periphery of the shaft; an elastic member that biases the rolling element toward one of the columnar portions adjacent to each other in the pocket; a housing that covers an outer periphery of the cage and the outer sleeve, and to which unidirectional rotation of the shaft is transmitted in accordance with the rolling positions of the rolling elements in the pocket portions. In a one-way clutch comprising: the retainer is formed on the base on the side opposite to the side on which each of the columnar portions is erected, with a coupling portion having an engaged portion extending cylindrically around the shaft, and the retainer is disposed within the housing so that an outer periphery of the coupling portion is aligned with an outer periphery of the outer sleeve and is coaxial with the outer sleeve; The housing has an inner diameter storage section which covers the outer periphery of each of the retainer and the outer sleeve which are arranged, an engaging section which engages with the engaged section in the axial direction to transmit rotation of the retainer to the housing is formed on the inner circumference, a restricting wall which restricts movement of the retainer and the outer sleeve toward one end side of the storage section in the axial direction is formed on one end side of the storage section facing an end face of the connecting section, and a cap which restricts deviation of the retainer and the outer sleeve from the insertion opening is fitted into an insertion opening of the retainer and the outer sleeve into the storage section which opens to the other end side of the storage section in the axial direction. A one-way clutch characterized by

2. 2. The one-way clutch according to claim 1, wherein the engaged portion is formed by cutting out a predetermined length from an end face of the coupling portion in a plurality of locations of the retainer in the axial direction.

3. 3. The one-way clutch according to claim 2, wherein the length by which the coupling portion extends from the end face of the base on which the columnar portion is erected is set to be longer than a predetermined length of the engaged portion.

4. 4. The one-way clutch according to claim 1, wherein the engaged portion and the engaging portion are set to a length such that a gap is generated between the end face of the connecting portion and the regulating wall when the engaged portion and the engaging portion are engaged with each other.

5. 5. The one-way clutch according to claim 1, wherein the retainer is fixed to the outer sleeve by pressing the retainer into the outer sleeve with a rectangular inner wall surface of the outer sleeve abutting against a prismatic side periphery of each of the columnar portions rising from the base.

6. The cap has an inner diameter portion through which the shaft is inserted, 6. The one-way clutch according to claim 1, wherein the housing has an inner diameter portion through which the shaft is inserted, on a side of the storage portion opposite to a side where the cap is fitted.

7. 7. The one-way clutch according to claim 1, wherein the outer sleeve has an outer circumferential surface in which arcuate surfaces and flat surfaces are alternately arranged.

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