摘要 |
INDEPENDENTLY ACTUATED PRESSURE RELIEF SYSTEM A pressure relief system for the primary hydraulic system of a large industrial machine wherein the biasing force biasing one of the pressure relief valves is supplied by the pilot hydraulic control system of the machine. A two-position valve is used to selectively change the biasing force in response to a temperature indicator. The two-position valve couples and decouples the pressure relief valve to and from the pilot control system hydraulic pump and the pilot hydraulic system sump. If the pressure relief valve is in communication through the two-position valve with the pilot hydraulic fluid sump, the biasing force is reduced against the pressure relief valve and the pressure in the primary hydraulic system opens the pressure relief valve and directs hydraulic fluid to the primary hydraulic fluid sump. |