| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wheel-supporting roller-bearing unit with an air compressor that is compact and capable of keeping resistance against the rotation of a hub 4c low, while maintaining good balance, and, when necessary, is capable of obtaining compressed air having sufficient pressure regardless of the travelling speed of an automobile. <P>SOLUTION: A plurality of cylinder holes 53 and 53 are located at a plurality of location evenly spaced around the circumferential direction on the inside of a cylinder block 50 connected and fastened to the inside end section in the axial direction of the hub 4c. Pistons 54 and 54 fit inside these cylinders holes 53 and 53, and are moved back and forth by a piston-drive mechanism 62 as the cylinder block 50 rotates. The air compressor 2c is a reciprocating-piston compressor, so it is possible to obtain the required air pressure regardless of the rotating speed. Also, by placing a plurality of cylinder holes 53, 53 and pistons 54, 54 at uniform intervals around in the circumferential direction, it is possible to suppress the resistance against the rotation of the hub 4c. <P>COPYRIGHT: (C)2008,JPO&INPIT |
