| 摘要 |
1,235,097. Hydrostatic transmission control. SPERRY RAND CORP. 27 Oct., 1969 [14 Nov., 1968], No. 52463/69. Heading F2D. A control for sharing the load between two hydrostatic transmissions A, B driving a common output shaft 18 comprises a servo 54 which adjusts the displacement of the pump 34 of the transmission B in response to the pressure differential in the high pressure lines 22, 36 of the transmissions. As shown a first hydrostatic transmission A has an electric motor 30 driving a variable displacement pump 20 in closed circuit with a fixed displacement motor 26 geared to the output shaft 18. The second transmission B has an electric motor 46 driving a variable displacement pump 34 in closed circuit with a fixed displacement motor 40 which is geared to the output shaft 18. The displacement of the pump 20 is controlled by a hand lever 28. The displacement of the pump 34 is controlled by a servo piston 54 axially slidable in a cylinder 50 supplied with pressure liquid from the high pressure lines 22, 36 through ducts 62, 64. If one transmission transmits more than its share of the load the pressure in its high pressure line (e.g. 22) rises. This increase in pressure is transmitted to the chamber 58 of the servo motor to move the piston 42 which increases the displacement of the pump 34, the pressure in the line 36 and thus the load transmitted by the second hydrostatic transmission. The servo 54 thus adjusts the displacement of the pump 34 to maintain the loads transmitted through the two transmissions equal. |
