GB689139A - Continuously regulatable hydraulic change speed transmission drive - Google Patents

Abstract

689,139. Hydraulic transmission. TRUDEL & CO. AKT.-GES. Jan. 24, 1951 [Oct. 20, 1950], No. 1873/51. Class 69 (ii). A continuously regulatable hydraulic change' speed drive comprising in a housing 1 an oil pump 10 and an oil motor 7 with the shaft 5 of the pump extending at right angles to the motor shaft 4, has a control plane 51 between the pump and the motor and oil flow control means through the wall forming said control plane permitting direct flow from the pump to the motor and vice-versa over separate oil flow passages for inflow and outflow of the actuating oil. A cover 8 forms the base plate for the primary motor (not shown) which is keyed to the shaft 5 to drive the pump 10 which has bores 54 housing ball-pistons 11, 20 spring urged against a ring 32a in a swash plate 9, the inclination of which is governed by a spring-loaded push-rod 16 actuated by a cam 14 secured to a spindle 14a attached to a control knob 12. The cam 14 can be continuously rotated if desired. The pump 10 has ports 53 and rotates over the control plane 51 which contains control slots or ports 52 and 52a. The motor 7 is housed in sleeve inserts 2 and 3 formed with annular channels 55 and 55a respectively and carrying discs 15 having cam tracks 15a. The motor has cylinders 58 with ports 57 and 57a and two ballpistons 19 spring urged against the track 15a. Oil from the pump flows from the central slots 52 into the annular channel 55 and through the port 57 into the cylinder 58, the pressure causing the ball-pistons 19 to ride up on the curved tracks 15a and thereby rotate the motor 7. Communicating slots 56 and 56a are relatively offset so that the port 57 is closed when the port 57a is open, and vice-versa. Oil from the pump circulates through the motor via port 57a, slot 56a, channel 55a, control slot 52a and into the pump port 53. The discs 15 may be exchanged for discs having tracks 15a of multiple curvilinear shape to change the number of motor piston strokes per revolution, the inserts 2 and 3 also being exchanged for inserts having the appropriate arrangement of control slots 56 and 56a. The housing has an oil filler 22 and all free spaces in the housing below the oil level 50 are in communication with the oil reservoir via ducts 60 and 61, the latter communicating with the channel 55a through an opening 62.