Jul 25, 2017
When the pressure oil enters the bottom of the plunger in the cylinder through the window of the fixed oil distribution shaft 4, the plunger protrudes outwardly and tightly against the inner wall of the stator, since the stator and the cylinder have an eccentricity. At the point of contact between the plunger and the stator, the stator has a reaction force against the plunger, the force can be decomposed into two components. When the oil pressure acting on the bottom of the plunger is p, the diameter of the plunger is d, and the angle between the forces is X, the force produces a torque to the cylinder to rotate the cylinder. The cylinder and then through the end of the drive shaft connected to the output torque and speed.
In the case of the above-mentioned analysis of a plunger generating torque, the torque generated on the plungers causes the cylinder to rotate and output the torque due to the fact that there are several plungers in the oil pressure zone. Radial piston hydraulic motors are used for the low speed large torque applications.