| 摘要 |
<p>The ball-screw lift device for a variable compression-ratio engine comprising a double-acting hydraulic control actuator (8) comprising an upper chamber (121) and a lower chamber (122) and at least one actuator piston (13) connected to a control rack (7), comprises: at least two balls (401, 402) or shutters each resting on a seat (403, 404) and respectively closing off each end of a transfer port (405) connecting the upper chamber (121) of the control actuator (8) to the lower chamber (122), said balls (401, 402) acting like a non-return valve when held on their seat (403, 404) by a spring (408, 409) in order to allow the hydraulic fluid to pass in just one direction; and lift means (410) comprising at least one electric motor (480) designed to turn at least one screw (481, 482) allowing at least one ball (401, 402) to be lifted off or set down on its seat (403, 404).</p> |
