Damper valve for hydraulic steering-gear servo motor

摘要

The servo motor is hydrostatic, or forms a hydraulic positive-displacement unit, and also acts as a steering damper, the damper valve being incorporated in the piping between motor and servo valve. A first passage through the damper valve is controlled by a lifting plug forming a non-return valve. A second passage with damping action is controlled by a plug functioning dependent on temperature. The first plug (31) lifts, and also turns dependent on temperature. On turning, it opens and shuts the first passage (25) or a bypass passage (34), which is controlled by the second plug (30) to give the damping effect, in the reverse-flow direction. The first plug can consist of a lifting ring working with drillings to form a non-return valve, and containing apertures or recesses (33). When the ring turns under the effect of temperature, these are brought to a varying degree into line with bypass passages or those controlled by the ring.