| 摘要 |
<p>A fraction control arrangement for a variator (10) with a pair of races (12, 14, 26) and at least one roller (28) which transfers drive from one to the other. The roller is movably mounted. Its motion enables the speed of one race to be varied relative to the speed of the other race. The variator has a hydraulic traction load actuator (117) which receives a hydraulic traction load pressure and in response urges the races and the rollers into engagement in order to provide traction between them. At least one hydraulic roller control actuator (32) receives opposed first and second reaction pressures and in response to apply a reaction force to the roller. A traction control valve (119, 119a) controls the traction load pressure and is operable in at least two modes. The relationship between traction load pressure and reaction force is different in the two modes.</p> |
