Patent GB-1022799-A (GB)
Title: Drive transmission systems
IPC: F16D25/10
Filed: 1965-02-05
Abstract: 1,022,799. Combinations of friction clutches and control thereof. GENERAL MOTORS CORPORATION. Feb. 5, 1965 [Feb. 27, 1964], No. 5075/65. Headings F2C, F2L and F2U. A transmission comprises a clutch 10 operable to transmit drive to a clutch 11 of a larger rated power capacity, the driving and driven members 36, 39 of clutch 10 being locked together by splines 41, 42 subsequent to slipping engagement of the clutch, the clutch 11 being automatically engaged subsequent to locking of the clutch 10. The driving member 36 is connected to an aircraft turbo-prop engine through shaft 12 and herring-bone toothed gears 19, 18 and the driven member 109 of clutch 11 is connected at 111 to shaft 14 of a compressor. The driven member 39 of clutch 10 is connected by splines 49, 52, Fig. 2, coupling member 44, splines 101, member 92 and splines 80 to the driving member 81, 82 of clutch 11. Pumps 143, 151 driven from the turbo-prop engine and from member 81 through gears 94, 159, 158, 162, respectively supply pressure fluid for controlling the clutches. When no drive is transmitted but with the engine operating pump 143 supplies fluid via line &c. 148, 174, 176, 172, 184, 182 to chamber 78 to move, with the aid of springs 78, members 44, 39 to the right to disengage clutch 10. To drive the shaft 14 and compressor. Clutch 10.-A valve 168 is moved by lever 192 to connect bore 172 with chamber 74 via ports 184, 181 to move member 44 to an apply position wherein inclined portions ofsplines 49, 52, Fig. 2, engage, springs 58 urging member 39 into engagement with member 36, the splines 49, 51 driving member 44; the clutch 10 is cooled by fluid passing through ports 189, 188. Pressure in chamber 74 is sufficient for clutch 10 to drive pump 151 and member 81, 82. As member 39 accelerates centrifugal action increases the fluid pressure in chamber 74 to increase the torque capacity of clutch 10 until the speeds of members 36, 39 are synchronized when splines 49, 52 fully mate whereby member 44 moves to the left wherein splines 41, 42 engage to lock the clutch 10, drive being transmitted directly to members 44 and 81, 82. In this position coolant passages 189 are blocked. Clutch 11.-Prior to lock-up of clutch 10 pump 151 supplies pressure to chamber 213 which passes fluid to chamber 248 and exhaust passages 276 so that springs 271 keep a valve element 199 in a limited flow position in which some fluid passes from chamber 213 via grooves 258 and passages 264 in spokes 251 fixed to sleeve 209 for lubricating and cooling clutch 11. When member 44 is moved to its lock-up position a member 61 moves to connect chamber 213 with bore 202 via passages 216, 215 and hence to clutch apply chambers 136, 138 via ports 229, 236, 239 and 231, 238, 241 to move pistons 126, 128 to apply the clutch 11 sufficient to effect initial rotation of member 109 and the compressor blades. As member 109 accelerates centrifugal fluid pressure in chambers 136, 138 increases the power capacity of clutch 11 to accelerate the output shaft 14. Initially fluid is also supplied to a chamber 277 to move valve 199 to the left to fully open the coolant passages 264; however, when member 109 and sleeve 209 begin accelerating centrifugal fluid pressure builds up in chamber 248 radially outward of exhaust passages 244 and with springs 271 the valve 199 is moved to the right to the limited flow position as shown in Fig. 1. For disengagement valve 168 is moved to connect bore 172 to release chamber 76 to move member 44 to the right; eventually ports 188 align with passages 189 and 181 to completely vent chamber 74. As member 44 moves spline 41, 42 disengage and passages 215 are closed by member 61. Clutch 11 slows down reducing the speed of pump 151 and hence the pressure in chambers 213, 136, 138, centrifugal pressure in chamber 136, 138 also dropping until springs 139, 141 move pistons 126, 128 to the clutchdisengaged position; bleed slots 140, 142 in pistons 126, 128 allow fluid in chambers 136, 138 to drain. All members are then in the disengaged position.