| 摘要 |
PURPOSE:To reduce power loss during axle rotation and elongate the life of a brake mechanism by improving the operative method of a brake band in a device which brakes a cam with the brake mechanism during the axle rotation in four wheel drive to turn on a clutch with the action of the cam surface. CONSTITUTION:When an axle 1 is rotated during four-wheel drive, a cam follower 21 rotated integrally with the axle 1 abuts against a slant surface 19b2 of a cam ring 19 to rotate the cam ring 19 so that either one of a claw 19a1-19a3 engages a wedge surface S1 to press a brake band 27 against a brake drum 26. Thus, a clutch 18 is moved right through a spring 24 by moving right the cam follower 21 along the slant surface 19b2 so that an inner sleeve 11 is connected to a main body 10 to rotate a wheel hub 5 integrally with the axle 1. Next, when the cam follower 21 rides over a flat surface 19b3, the claw of the cam ring 19 is disengaged from the wedge surface S1 so that the braking torque acting on both rings 19, 20 is reduced. |
