Typical structure of vane motor
Figure I shows a double acting vane motor structure. The motor is mainly composed of stator 1, rotor 2, blade 3, port plate 11, housing 7, transmission shaft 6 and other parts. Compared with double acting vane pump, double acting vane motor has the following characteristics in structure.
① The inner surface curve of stator consists of four working sections and four transition sections.
② The number of blades is usually even (the number of blades in the motor shown in Fig. I is 12). The blades are symmetrically arranged in the rotor, and the radial hydraulic pressure on the rotor is balanced during operation, so the bearing force is small.
③ The blade in the motor is placed radially with an inclination angle of 0 ° and the blade tip is symmetrically chamfered to meet the requirements of forward and reverse rotation.
④ The swallow spring 5 fixed by the pin 4 is installed at the bottom of the blade to ensure that the blade can cling to the inner surface of the stator to form a closed volume when the motor is started, so as to prevent the high and low pressure cavities from colluding.
⑤ The bottom of the blade is filled with high-pressure oil to make the blade and stator contact reliably. In order to ensure that the bottom of the blade can be filled with high-pressure oil during the forward and reverse rotation of the motor, a group of check valves with special structure need to be installed in the motor shell 7. In figure I, 8 and 10 are the seats, and 9 is the steel ball spool of the check valve. The lower right figure is the schematic diagram of the working principle of the valve.
In order to improve the working pressure and speed of vane motor, the pressing force between vane and stator should be reduced to reduce the contact wear. Like vane pump, the methods of reducing the thickness of vane, double vane structure, spring vane structure, daughter vane structure and stepped vane structure are usually adopted to reduce the contact stress between vane and stator, reduce wear and improve the service life of motor.
In order to improve the volumetric efficiency of vane motor, the floating valve plate can be used. Under the action of pressure oil, the valve plate is pressed to the rotor end face. When the end face is worn, the axial clearance can be automatically compensated.