| 摘要 |
1437610 Valves G M SOMMER CO Inc 24 Sept 1973 [22 Sept 1972] 44736/73 Heading F2V [Also in Division G3] A combined control and pressure relief valve is used to alter the pressure of the hydraulic fluid applied to a torque coupling operating on the viscous shear principle in an automatic speed control system (see Division G3). The valve includes a supply port 124 connected to a pump and to the coupling and a venting connection 24 and has a coil 140 which is energized by a speed error signal to move flapper plate 130 relative to shoulder 132 and thus charge the system pressure to change the output speed of the coupling. The plate 130 is held away from shoulder 132 by a spring and is provided with a bleed hole 156. In an alternative construction, Fig. 4 (not shown), where a large flow of hydraulic fluid is needed for cooling purposes the electrically controlled valve is used as a pilot valve for changing the operating pressure on the operating piston of a main pressure relief valve. |
