The performance obtainable from a hydrostatic transmission is compared with current conventional tractor transmissions. Having shown that the present-day hydrostatic unit meets all vehicle requirements with the obvious advantages of true stepless transmission, the reasons for selection of a gearbox replacement unit are considered and, further, the use of a variable displacement motor with variable displacement pump.
The limitations of maximum pressure, speed, and displacement of both swash plate and tilting head units are discussed along with the specific design features of the Taurodyne. The latter represents a low cost reliable unit with wide performance characteristics.
Alternative forms of control which have been developed to suit various vehicle duties are described, and some details of typical installations and the exhaustive reliability trials conducted on both test rigs and vehicles under extreme operating conditions are mentioned.