Patent GB-1009481-A (GB)
Title: Improvements in torque transmitting apparatus
IPC: F16H47/12
Filed: 1962-06-20
Abstract: 1,009,481. Hydro-mechanical transmissions. INPOWER WORKS (PROPRIETARY) Ltd. June 20, 1962 [July 3, 1961], No. 23828/62. Headings F2C and F2D. A transmission comprises an hydraulic coupling having a carrier coaxial or integral with a drum which retains a layer of hydraulic fluid formed during rotation of the carrier, and a vaned wheel passing through the layer of liquid and being mounted on the carrier about an axis spaced from the carrier axis, the vaned wheel driving a sun wheel fast with an output shaft coaxial with the carrier axis. Several wheels at different radial distances from the carrier axis may be provided and drive individual output suns, the depth of the layer being controlled to determine which of the wheels are driven. As shown in Fig. 3, a driving drum 4 has a vaned wheel 18 rotatably mounted therein, the wheel 18 driving an output sun 14 through gears 20, 16. The wheel 18 is balanced by a similar wheel (not shown) similarly geared to the sun 14, and a pair of vaned wheels 6 are geared to an output sun 44, another pair of vaned wheels (not shown) driving an output sun 46. The suns 14, 46, 44 drive gears 110, 106, 104, which mesh gears 130, 128, 126, mounted on an output shaft 122, the gears 130, 128 being mounted by way of overrunning clutches 120, 124. Gear 110 is slidably splined on a shaft 112 fast with the sun 14 and is slidable to the dotted line position in which it meshes a reverse idler 116 meshing a gear 118 on the output shaft to give reverse drive. The pairs of vaned wheels are disposed at different radial distances from the axis of the drum, and the depth of the centrifugal ring of fluid is variable by a scoop 32 which is pivotable from the position shown in which the entrance 30 is adjacent the drum periphery so that all the vaned wheels are clear of the fluid ring to positions in which the pairs of vaned wheels are successively brought into the fluid layer. Thus as the scoop 32 is moved inwardly the pair of wheels 18 is first brought into play driving the output shaft 122 at a first ratio through gears 20, 16, 14, 110, 130; then the second pair of wheels drives the output shaft through the sun 46 and gears 106, 128 to give second gear as permitted by the overrunning clutch 120; and in its inmost position the wheels 6 are driven and drive the output shaft at third ratio the second and first trains overrunning. In a modification, Fig. 6, two pairs of vaned wheels 8, 18 are disposed in separate compartments of a driving drum 4, the wheels 8 being disposed in chambers 242 communicating through passages 240 with an annular chamber 238 having a scoop tube 228 determining the depth of fluid in the chambers 242; the wheels 18 being disposed in chambers 224 communicating through ports 230 with an annular chamber 236 having a scoop 226 to determine the filling of the chambers 224. The wheel 18 is connected by a planet 222 through an idler 220 to a sun 204 which is fast with a sun 254 of an output epicyclic train which has a ring gear 256 drivable from the wheels 8. A one-way brake 276 is provided between the ring gear 246 and a stationary housing, and the driven carrier of the output train is clutchable by a double-dog clutch sleeve 258 directly to an output shaft 262, or is connectable thereto through a reverse train 256, 274, 268, 266, 264. For first gear liquid is introduced into compartments 224 with compartments 242 empty, so that the sun 254 is driven and the ring 246 is stationed by the brake 276; second gear is obtained by introducing liquid to compartments 242 and emptying compartments 224, thus driving the ring 246, the sun 254 being stationed by a one-way brake 208, and direct drive is given by filling both sets of compartments so that the output train is locked solid. In order to give engine braking an overrunning clutch 206 is provided between the output shaft 262 and the input drum 4. In another modification, Fig. 8, vaned wheels 8, 18 are disposed in separate compartments, and the wheels 18 drive a sun 300 fast with a gear 344 which can be clutched to an output shaft 338 by a clutch sleeve 342, the gear 344 meshing a gear 326 on a countershaft 332 which can be clutched to output gear pairs 334, 340 and 328, 336. The vaned wheels 8 drive a countershaft 354 clutchable to output gear pairs 352, 340 and 348, 336. An overrunning clutch 302 is provided between the output shaft 338 and the driving drum to provide for an engine braking. In a modification of this arrangement the vaned wheels drive the input gears of a simple constant-mesh forward and reverse gear. Instead of the driving drums forming the carrier for the vaned wheels and planet gears, a freely rotatable fluid retaining drum may be disposed coaxially about a driving carrier. Instead of the planet wheels fast with the vaned wheels driving their respective sun gears through idle planet gears, the planets may be connected to the sun gears through idle planet gears, the planets may be connected to the sun gears by means of chains. The vanes of the wheels may be curved to retain liquid therein, alternatively the vanes may be straight as shown in Fig. 12, in which case a shroud 454 is provided on the carrier in order to retain liquid between the vanes. The hydraulic coupling instead of driving the input shafts of a following mechanical change-speed gear, may drive separate output shafts. Reference has been directed by the Comptroller to Specification 949,175.