SEAL

PROBLEM TO BE SOLVED: To provide a stabilized sealing capability of a seal and reduce its cost. SOLUTION: A seal 6 has an annular chamber 10 formed under a combination of an inner annular member 7 and an outer annular amber 8. A seal air 9 is arranged in the annular chamber 10 and an opposing section A1 at the inner annular member 7 and the outer annular member 8 is closed by the seal member 9. In addition, the other opposing section A, is made such that an end surface 8c of a cylindrical section 8a of the outer annular member 8 is covered by a relief part 7d of an outer flange 7b of the inner annular member 7. Then, a clearance α between the outer flange 7b and a side surface 4a of an oil seal retainer and a clearance β at the opposing section A2 can be set upon completion of their press fitting. These clearances α and β may become a labyrinth so as to enable a sealing capability to be increased. Thus, it does not becomes necessary to use another labyrinth seal together with the former one and a desired sealing capability can be attained only with one step of assembling the seal 6.