Patent GB-407510-A (GB)
Title: Change speed gearing for vehicles
IPC: F16H47/07
Filed: 1933-01-31
Abstract: 407,510. Hydraulic transmission of power. FOTTINGER, H., 65, Berlinerstrasse, Wilmersdorf, Berlin, KRUCKENBERG, F., and STEDEFELD, C., 16B, Ellernstrasse, Hanover, both in Germany. Jan. 31, 1933, No. 3017. Convention date, Feb. 1, 1932. [Class 69 (ii).] Variable-speed gearing, particularly for railway vehicles, comprises Fottinger hydraulic turbo-gearing in series in advance of non- epicyclic toothed variablespeed gearing and the rotating parts of the gear include the secondary part of a F÷ttinger stationary-vane torque - increasing transformer at all speeds. The transformer comprises a driving pump-wheel 27, a driven turbine-wheel 29, and a stationary wheel of vanes 31, and by virtue of its selfregulating torque feature it serves to bridge the gaps between the ratios of the mechanical gearing and give a smoothly-variable torque change. In the form shown in Fig. 1 two transformers 31, 32 are geared up to a driving-shaft 21 and either transformer is supplied with oil or water from a manually-controlled pump, the other being emptied according to which of two speed trams 37, 38 or 35, 36 is to drive a driven-shaft 39. In a modification of this arrangement, Fig. 3 not shown, both transformers are arranged on a common single countershaft and in a three-speed arrangement, Fig. 4 not shown, three such transformers are arranged on a common driving-shaft and there are two parallel countershafts geared to an aligned driven-shaft. A further modification, Fig. 5, not shown, uses only a single countershaft carrying two of the transformers, the third being on the driving-shaft. The modification shown in Fig. 6 uses an auxiliary two-speed gear operated by a dog-clutch 64 to obtain lower ratios for use when a trailer is to be attached to the vehicle. In the gear shown in Fig. 7 the two speeds are brought in by ordinary hydraulic couplings 67, 72 not of the stationary-vane type. The first gear wheel 65 of the gear is driven from the shaft 21 by a stationary-vane transformer 31 and to increase the efficiency at high speeds this transformer can be emptied, drive being taken through an ordinary parallel hydraulic coupling 77. Instead of providing a separate coupling 77 the stationary vanes of the transformer 31 may be axially movable out of the liquid-circuit. This form of gear may have a single countershaft with both couplings 67, 72 mounted on it and the low-speed coupling 67 may be replaced by a free-wheel clutch. In Fig. 10 a stationary-vane transformer 31 is used in series with an ordinary change-speed gear of the sliding wheel or constant-mesh type, the latter being operated by friction, dog, or synchronized-dog clutches. Friction clutches 87, 88, 91 are used in Fig. 10, the lowest two speeds being connected to the driving-shaft 21 through a free-wheel 85 so that all the clutches may be in engagement simultaneously Fig. 11 shows a combined two-speed gear and bevel reversing-gear for use in a vehicle. A driving- shaft 21 drives through oppositely-rotating bevels 97, 98, the pump-vanes 101 of two transformers, the turbine-vanes 105, 106 of which are secured to an inner shaft 107 which drives a parallel shaft 119 through two-speed gearing actuated by a friction clutch 117. Either transformer drives to give forward or reversed drive. The shaft 119 may, as shown, drive the vehicle axle-shaft through coupling- rods 120, or it may be the axle-shaft, or it may surround the axle-shaft and be yieldingly connected to it. In order to prevent the driven vanes of the transformers from racing during a speed change they are provided with centrifugal brakes or are connected to the driving vanes through free-wheel clutches 122, 123, Figs. 12 and 13 show an arrangement in which two twospeed counter-shaft gears are each adapted to drive an axle but in reverse directions, either gear being used as driver according to which transformer is supplied with fluid. The driving- shaft 21 is geared up at 22 to a shaft 124 which drives bevels 127, 158 which drive the changespeed gears through pairs of transformers 147, 152, 141, 144. The frames 130 of the changespeed gears, which carry the countershafts 129, are semi-sprung, being journalled on the axles 125, 126 and connected through springs 133 to the sprung frame 134 of the vehicle.