Patent ID: 8272487

Claim:
A rotation transmission device comprising: a cylindrical housing having a first end closed with a wall formed with a shaft hole, and a second end constituting an open end; a torque transmission shaft inserted through said shaft hole into said housing; an inner ring coupled to an end of said torque transmission shaft; an outer ring provided around said inner ring; a first bearing fitted to an inner-diameter surface of said housing and rotatably supporting said outer ring; a second bearing fitted to an outer-diameter surface of said inner ring at the open end of said housing, and supporting said inner ring and said outer ring so as to be rotatable relative to each other; a two-way clutch provided between said inner ring and said outer ring for transmitting and blocking rotation torque therebetween; an electromagnetic clutch provided adjacent to said two-way clutch for controlling engagement and disengagement of said two-way clutch; a first seal member sealing a clearance between an inner-diameter surface of said shaft hole and an outer-diameter surface of said torque transmission shaft; and a second seal member sealing a clearance between an inner-diameter surface of said open end of said housing and an outer-diameter surface of said outer ring; wherein lubricating grease of the same quality is used for said second bearing and said two-way clutch, and wherein said second bearing has first and second sides and includes a seal member on said first side and includes no seal member on said second side, said second bearing being mounted with said second side facing said two-way clutch; and wherein said first bearing is an open type bearing having no seals, and including a labyrinth provided on one side thereof facing the open end of said housing to prevent lubricating grease from leaking out; and wherein a pair of snap rings with different diameters are attached, respectively, to the inner-diameter surface of said housing and to the outer-diameter surface of said outer ring so that said snap rings radially face each other, defining a clearance between said snap rings as said labyrinth.