| 摘要 |
1,135,512. Toothed gearing; hydraulic drive transmission. J. BINNS. 16 Nov., 1966 [21 July, 1966], No. 51264/66. Headings F2C and F2Q. [Also in Division B3] To eliminate backlash from a saddle or carriage feed mechanism for a machine tool such as a lathe, including a fixed rack 8 meshed by two spaced apart pinions A, B rotatably mounted on the carriage 16 and connected by separate gear trains 36, 38, 40 and 42, 44, 46 to oppositely handed helical gears 34, 32 secured on an axially floating drive shaft 30, an axial force proportional to the torque loading on the mechanism is applied to the shaft 30 by an hydraulic ram 60. This tends to rotate the pinions A, B in opposite senses to take up backlash. The shaft 30 is driven through gears 26, 28 by a reversible hydraulic motor 22 connected by lines 84, 86, a stop valve 102, and lines 106, 104 to a variable displacement pump 94 driven by an electric motor 96. Lines 76, 78 branching from the lines 84, 86 supply the twin piston single-acting ram 60 with fluid at drive circuit pressures, the latter being proportional to the torque load on the gearing. A control unit 100 monitors motor 22 speed or position. Pressure relief valves 122, 124, 126, 128 give overload protection for the gearing and hydraulic system. A variable displacement pump 110 driven by an electric motor 114 pressurizes and tops up the main hydraulic drive circuit via a restrictor 116, a heat exchanger 112 and a line 134, and also provides servo pressure to the stop valve 102 and to the displacement control 136 of the pump 94, and counterpressure, through a line 138, to the ram 60. |
