Studies on the Hydrostatic Transmission of Tractors (I)
Static Characteristics of Closed Circuit
1972 Volume 34 Issue 2 Pages 114-123
Details
1972 Volume 34 Issue 2 Pages 114-123
Static characteristics of closed circuit hydrostatic transmission in bench test set-up were scrutinized quantitatively.
Unlike fixed-displacement axial-plunger motor, pump used varies continuously its displacement from zero to 30cc/rev.
Analyses reveal following findings;
1) Resonant phenomena within fluid lines might appear at 1000rpm in input shaft, and almost identical with output shaft due to inherent periodic variations of flow rate and torque.
2) Maximum overall transmission efficiency can be obtained at allowable maximum line pressure under constant speed ratio.
Torque ratio draws nearly linear relationship with speed ratio.
3) P/μn and T/nμD, both are dimensionless terms, show disobedience to wilson's expression. It is of greatly interest to recognize that kinematic viscosity of hydraulic oil plays significant roles for the transmission efficiency.
4) Leakage of pump increases linearly up to 1800rpm in input shaft, after that increases more rapidly. It indicates the failure of application of the theory of laminar flow.
