| 摘要 |
1515200 Starting engines; turning gear TWIN DISC Inc 30 Dec 1975 [8 Jan 1975] 53235/75 Heading F1K In order to prevent overspeed and mechanical shock in the drive 15-25 and over-run clutch 14 of the auxiliary drive of a starting mechanism of the type having an auxiliary drive to provide break away and a main drive 2, 5, 5', 6 to 12 to accelerate the load, when turning, to an appropriate speed, an hydraulic retarder 40 is arranged to limit the initial r.p.m. of the auxiliary drive input shaft 24 until backlash and load are taken up, the hydraulic fluid then being dumped via lines 80, 53 on a signal to solenoid 46 of valve 48 which causes dump line 53 to open and a reduced pressure signal via line 55 to open dump valve 60, to allow the auxiliary drive to reach its full speed. The torque converter TC is 'dumped' initially to reduce 'drag' on the auxiliary system. The hydraulic retarder comprises an hydraulically coupled device having one of the associated vane portions fixed with respect to the starter mechanism housing. The valve 48, Fig. 3, is maintained in the non-dump mode by fluidpressure from by-pass 49 acting through orifice 47, on the end of piston 50a. Solenoid plunger 46a closes the orifice 47 to allow the control pressure to decay via a bleed in the piston 50, the piston moving under the action of spring 70 to the dump position. Valve 60 is arranged to bleed fluid at all times from the coupling for cooling purposes, a further discharge port being opened when the fluidpressure at outlet 54 of valve 48 is reduced when piston 50 moves to the dump position. The retarder may be used as a safety device or a speed-controller by refilling with fluid when appropriate. The auxiliary drive produces a load running speed of 6 r.p.m. The power sources may be electric motors 3 and 28 and the load a turbine GT and generator G. |
