| 摘要 |
<p>A housing for a disc brake incorporates an expander mechanism formed by two pressure plates and, a stack of friction discs between one plate and a braking surface, and a single friction disc between the other plate and another braking surface. The one plate is formed by separate inner and outer concentric rings, and the inner ring and the other plate are slidably coupled against relative angular movement. In normal braking an annular piston works in an annular hydraulic cylinder in the other plate to urge the inner ring and the plate axially apart so that the single friction disc engages with the braking surface and the inner ring engages with a corresponding inner ring of friction lining material on the adjacent disc of the stack, thus urging the stack into engagement with the braking surface. The brake can also be applied mechanically through a transmission member or by an hydraulic actuator by moving the outer ring angularly with respect to the other plate causing balls to ride out of inclined recesses in adjacent faces of the outer ring and plate so that the outer ring engages with a corresponding outer ring of friction lining material on the adjacent disc of the stack. In this manner of operation a servo effect is obtained and helical movement of the annular piston is eliminated.</p> |
