| 摘要 |
<p>A belt tensioning device (18) includes a resilient coupling (34, 54, 42) which interconnects an idler pulley hub (62) and a stationary mounting member (20). A ratchet and pawl mechanism (102, 114) interconnects the hub (62) and the stationary mounting member (20) to prevent the belt (10) from overcoming the biasing force of the tensioning device (18) during high belt loads. A resilient biasing element such as an elastomeric element (54, 56) is located between the ratchet and pawl mechanism (102, 114) and the stationary mounting member (20) to allow limited movement of the idler pulley hub (62) away from a belt (10) in order to relieve belt tension such as caused during thermal expansion of an engine block (24).</p> |
