摘要 |
<p>A hydraulic transmission unit comprises at least one pressure regulation valve (1) and a pilot control valve (2) which is connected to the pressure regulation valve (1) by a pilot control line (35). A pre-filling valve (3, 303) sets a pre-filling pressure (p—3) to avoid draining of a clutch (20) and the lines (231, 331) connected to the clutch (20) in an operating condition in which the clutch (20) is not actuated. To avoid draining when the clutch when in the operating condition, the pilot control line (35) is also connected to at least one line (236, 238, 336, 338) which is pressurized with a second pre-filling pressure (p—3).</p> |