Abstract: [Object] A unidirectional clutch can reduce a backlash without increasing the number of components, and also can improve silence and durability. [Means of Solving Problem] In a planet gear member 4 including a planet gear 4a which meshes an internal gear 2b of an outer member 2, locking teeth 4b are provided coaxially and integrally relative to the planet gear through a flange 4c. In an inner member 3, U-shaped wall portions 3b receiving the locking teeth 4b are provided. In the U-shaped wall portion, an engaging portion 5 is provided so that teeth of one portion of the locking teeth can engage. A locked state is attained by the locking teeth, so that even if the planet gear receives a restriction of the number of teeth, the number of the teeth (pitch) of the locking teeth can be finely set arbitrarily.

Abstract: A one-way clutch of an inscribed gear type has a cylindrical outer member having an inner gear at an inner circumference thereof; an inner member rotatably disposed in an inside space of the inner gear, and having gear receivers and a lock edge on one side in a circumferential direction of the gear receiver; and a planetary gear received rollably in each of the gear receivers to mesh with the inner gear. Shafts are projecting from both ends of the planetary gear, and bearing recesses are formed on the gear receiver to receive the shaft. By the engagement between the shafts and the bearing recesses, the planetary gear allows a circumferential displacement within a predetermined range with respect to the inner member required for engaging to or disengaging from the lock edge, and the planetary gear is prohibited from being displaced inward in a radial direction of the inner member.

Abstract: A one-way clutch includes shafts 56 and 58 projecting from both ends in the axial direction of a planetary gear 44 or 46; and bearing recesses 60 and 62 formed on both end walls in the axial direction of a gear receiver 40 or 42 in such a manner as to be released on the outer peripheral side of an inner member 20 so as to receive the shafts 56 and 58. The fitting between the shafts 56 and 58 and the bearing recesses 60 and 62 allows a circumferential displacement of the planetary gear 44 or 46 within a predetermined range with respect to the inner member 20, the displacement being required for fitting to or releasing from a lock edge 52 or 54, so as to prohibit the planetary gear 44 or 46 from being displaced inward in the radial direction of the inner member 20.

Abstract: [Object] A unidirectional clutch can reduce a backlash without increasing the number of components, and also can improve silence and durability. [Means of Solving Problem] In a planet gear member 4 including a planet gear 4a which meshes an internal gear 2b of an outer member 2,locking teeth 4b are provided coaxially and integrally relative to the planet gear through a flange 4c. In an inner member 3, U-shaped wall portions 3b receiving the locking teeth 4b are provided. In the U-shaped wall portion, an engaging portion 5 is provided so that teeth of one portion of the locking teeth can engage. A locked state is attained by the locking teeth, so that even if the planet gear receives a restriction of the number of teeth, the number of the teeth (pitch) of the locking teeth can be finely set arbitrarily.