Patent GB-973055-A (GB)
IPC: F16D48/04
Filed: 1962-10-16
Abstract: 973,055. Clutch control; friction clutches. TWIN DISC CLUTCH CO. Oct. 16, 1962 [April 16, 1962], No. 39177/62. Headings F2C, F2D and F2L. A power transmission comprises a constant speed power source, such as an electric motor, turbine or I.C. engine, driving a bladed member operating in a fluid medium through a controllable-slip friction disc clutch which is supplied with cooling fluid. Numerous arrangements are described for driving the impeller of an hydraulic torque converter or centrifugal pump through an hydraulically actuated friction clutch provided with separate pumps or a common pump for supplying the operating and cooling liquids. Control of the clutch may be manual or automatic, and the clutch may be mounted externally of or within the torque converter housing, which may be stationary or rotatable. The clutch and torque converter may have separate or common liquid supply. As applied to a drive for an electric rail vehicle the torque converter output shaft is connected to a clutch-controlled bevel pinion type reversing gear. The embodiments include:- (a) Fig. 1.-The power source 10 drives the impeller 30 of a stationary-housing torque converter 31 through an hydraulic multi-disc clutch 16, the fixed piston-moving cylinder actuator 19 of which is supplied with pressure liquid by a pump 39, the flow to the pressure chamber 22 through ducts 46, 47 being regulated by a manual control valve 43, 44. The torque converter liquid is supplied by a pump 36 and the coolant for the clutch by a pump 24 through ducts 25, 26. Part of the coolant passes through a port 28 to a balance chamber 23. Modifications, Figs. 2 and 3 (not shown), applicable to torque converters with rotatable housings are also described, the latter incorporating a single pump for supplying the clutch and torque converter liquid. (b) Fig. 5.-An arrangement similar to that of Fig. 1 includes a disc brake 117 between the clutch and impeller to prevent torque application to the latter when inoperative due to coolant drag on the clutch discs. In the clutchdisengaged condition shown the brake is held engaged by springs 118 which are over-ridden by liquid supplied to a pressure chamber 115 when valve 43 is operated for clutch engagement. (c) Fig. 4.-In this arrangement the clutch is normally held engaged, slip being introduced automatically at a predetermined converter output torque or speed. For this purpose pitot tubes 105, 106 in the converter reactor element are arranged so that the pressure difference at or near stall (for torque control) or racing (for speed control) operates a spring-loaded piston 98 connected to the control valve 96, which moves to the right to open an exhaust port 103 and allow the clutch to slip. (d) Fig. 6.-In this case the clutch 132 is disposed within the converter, between the impeller and turbine elements 134, 136. The actuator piston 139 is normally held disengaged by release springs 141, over-ridden by pressure liquid supplied from a pump 148 through an axial port 147 in the cylinder end wall 143. The pump 148 supplies common operating liquid to the clutch and converter, so that the basic pressure in the converter toroidal circuit varies with that in the clutch actuator. This arrangement may be modified by omitting the clutch-release springs, the piston 139 being held in the disengaged condition by pressure liquid from a second pump (206), Fig. 8 (not shown), or by providing a brake element (238), Fig. 9 (not shown), to prevent undesired rotation of the converter impeller as described with reference to Fig. 5 above. (e) Fig. 10.-In a drive for an electric rail vehicle a pump 299 supplies pressure liquid to the converter 272 and clutch 263, a valve 311 controlling the flow through pipes 316, 319 to the clutch pressure and balance chambers 269, 270, and through the clutch coolant supply pipe 315. The converter output shaft 275 is connected to the final drive-shaft 282 through a bevel pinion reversing gear 281, controlled by conjointly operated clutches 289, 293 through a selector valve 327. In a modified arrangement, Fig. 11 (not shown), the clutches 289, 293 are controllable separately so that they may be used for vehicle braking, and in a second modification, Fig. 12 (not shown), the main clutch 263 is combined with a brake (498) with a common actuator, while in a third modification, Fig. 13 (not shown), a separate hydraulic brake or retarder (551) is provided on the converter output shaft. (f) Fig. 14.-In this arrangement the construction according to Fig. 10 is additionally provided with a spur gear 586 between the main clutch 569 and an auxiliary clutch 579, so that by releasing the former and engaging the latter the power source 260 may drive the converter impeller at a higher speed if desired. (g) Fig. 15 (not shown).-Comprises an arrangement similar to that of Fig. 1 for driving the impeller of a centrifugal pump.