Research Of Equal Contact Stress Inner Curve Based On Radial Piston Motor

Hydrostatic transmission is widely used in construction machine. The research of one of its hard cores, low speed high torque radial piston motor, is very important. To directly estimate the life of this kind of motor, and to design a orbit curve with the longest life at same condition, this paper gives theoretic research of the equal contact stress inner curve of radial piston motor. The research is divided into four parts:1) Taken all forces the piston endured into consideration when radial piston motor working, the force between roller (or ball) and orbit is deduced. The simple style of the press expression can be confirmed by ignoring minor influence factors after analysis all factors that will influence this press.2) Applied Hertz theory and the force between roller (or ball) and orbit, the equation groups for calculating equal contact stress curve are listed. The answer of the equation groups is calculated by utilizing the software MATLAB. The result of the simulation to this answer proved that theanswer is reasonable and the design rule also be discussed from the analysis result.3) Based on the analysis result of equal contact stress curve and the theory of elasto-hydrodynamic lubrication, the expression of the oil film thickness between roller (or ball) and orbit are calculated. The simulation result proved that the thickness of oil film is enough for bearing and lubricating.4) Based on the theory analysis of the equal contact stress inner curve, the experiment research is discussed, and the project of experiment is also designed.