Patent GB-463543-A (GB)
Title: Improvements in or relating to hydraulic power transmission gears
IPC: F16H39/10
Filed: 1935-06-27
Abstract: 463,543. Hydraulic transmission of power. GOLZ, E. June 27, 1935, No. 18455. [A Specification was laid open to inspection under Sect. 91 of the Acts, Dec. 28, 1935.] [Class 69 (ii)] [Also in Group II] In a hydraulic transmission gear having fixed and adjustable swashplates, the latter is adjusted by opposite pistons rotating with it ; the cylinders of the pistons are connected one to the pressure in the gear and the other to discharge or vice versa according to the movement of a loaded valve to one or the other of two end positions, so that the swashplate is adjusted in accordance with 'the load on the gear. In the form shown in Fig. 1, the pump casing 3 is carried by the driving shaft 1 and its pistons co-operate with a fixed swashplate 18. The motor casing 20a is supported by the fixed casing 2, and its pistons co-operate with the adjustable swashplate 23 carried by the driven shaft 12. Cylinders 26, 26a carried by the driven shaft have pistons 25 acting on the swashplate 23. Liquid collecting in the casing 2 is conveyed by an auxiliary pump 7 to a centrifuge 4 rotating with the main pump, where air is separated and returns to the casing through apertures 9, the purified liquid passing through pipes 10, 10a provided with non-return valves 11 to passages 17 connecting the cylinders of the pump and motor, and communicating through non-return valves 40 with a bore 29 in the driven shaft. In the outer end of the bore is a piston valve 27 loaded by an adjustable spring 28, and provided with ports and passages so that in the position shown, pressure liquid from the bore 29 can enter the cylinder 26a, while the cylinder 26 is connected to the interior of the casing 2, to cause clockwise adjustment of the swashplate 23. In the outer end position of the valve, the cylinder 26a is connected to the casing, and the cylinder 26 to the bore 29. The spring 28 is adjusted to balance a given liquid pressure in the bore and hold the valve in a position intermediate its end positions. When the pressure in the bore on account of variations in load departs from this value, the valve is moved into an end position, and the swashplate thereby adjusted in the manner requisite to bring the pressure again to the determined value. The spring 28 can be so greatly compressed, that the valve is thereby permanently held in that end position, which causes the swashplate to be moved into position for obtaining reverse drive. During forward drive, the vertical position of the swashplate corresponds to direct drive, and adjustment to one side enables gear ratios less than unity to be obtained, while adjustment to the other side secures gear ratios greater than unity. In another form, the spring 28 acts on the valve 27 through a lever 274, Fig. 2, the passages 17 are formed in an intermediate disc 170 carried by the driven shaft, the non- adjustable swashplate 180 is carried by a hollow shaft 120, and both swashplates comprise rings 35a and sector-shaped grooves 36a, 37a, supplied with liquid through passages 172 or 38. In a further form, the centrifuge is separate from the pump 3 and driven by gearing from the shaft of the pump 7. It may consist of a onepiece body 140, Fig. 4, mounted in a forked bearing 210<1>, and provided with a radial partition 141.