Hydro-thoma Limited

George Duncan MacRae Arnold

Christian Thoma

An improved hydrostatic transmission useful as a speed changing device having a single output shaft or a pair of outwardly extending shafts for use, for example, in small vehicles such as lawn and garden tractors. The hydrostatic transmission output may be mechanically coupled to the wheel driving axle by a gear or chain drive, or alternatively may have such means included in the same housing package containing the hydrostatic transmission. When a differential action is needed between the drive wheels of the vehicle, the differential may then also be included in the same housing package. In whichever of such configurations, the hydrostatic transmission comprises a radial piston pump fluidly coupled to a single or twin larger displacement axial piston motor of the swash-plate type by means of a fluid coupling valve supported by the housing. The pump is superimposed on the motor for compactness and the respective operational advantages that each type has is optimised for overall improved performance of the hydrostatic transmission.

Growing community of inventors

Jersey, United Kingdom

George Duncan MacRae Arnold