Typical structure of axial piston motor
Typical structure of axial piston motor
Because the working principle of axial piston motor and axial piston pump is reversible and the structure is basically the same, most products can be used as pumps or motors (for example, cy series swash plate axial piston pump, which is widely used in China, can generally be used as hydraulic motors). Therefore, only one example of the straight axis and oblique axis axial piston motors is introduced here.
(1) Figure t shows the typical structure of straight shaft double swash plate rotary cylinder quantitative motor. The motor has double swash plate 2, the number of plunger is doubled, and the diameter of plunger 1 is increased at the same time, so the displacement is increased, the diameter of plunger distribution circle is increased, and the speed is forced to decrease, so it belongs to low speed motor. The cylinder block is integrated with the shaft. The pressure oil enters into the piston cylinder hole through the end cover 6, flow channel B, floating valve plate 4-side window, and the flow channel of cylinder shaft 3, and pushes a pair of plunger groups to both ends along the axial direction at the same time. Because the slipper at the head of the plunger is tightly pressed on the inclined plane of the swash plate 2, the pressure oil generates a tangential component force on the plunger thrust, which pushes the slipper to slide along the inclined plane of the swash plate and makes the cylinder block rotate to output torque. When the plunger group slides over the top dead center, the liquid that has finished the work will be discharged along the channel a by the plunger group that is pressed back by the inclined plane of the swashplate. Because the cylinder block is integrated with the transmission shaft, the cylinder block has no motion freedom of axial compensation, and the floating port plate 4 is used to realize the axial floating. In order to make the hydraulic thrust equal to constant (because the pressing force of core tube 5 is constant), and the cylinder size is large, the plunger is generally taken as even number 10. The double swash plate 2 counteracts the axial force, so that the bearing load is not too large. Because of the low speed, the valve plate can be made smaller, so the axial thrust on the cylinder block is also smaller. The domestic SXM series double swash plate axial piston motor is of this structure. The maximum pressure range is 12.5 ~ 32Mpa, the displacement range is 0.25 ~ 1.60ml/r, the rated speed range is 5 ~ 250r / min, and the rated output torque range is 740 ~ 3700n · M.
(2) The typical structure of oblique axial piston motor is shown in Fig. u. it is a hingeless axial hydraulic motor. Heavy duty roller bearing 6 allows the motor to withstand considerable external axial and radial loads. The connecting rod of the motor is made into a cone and rotates with the cylinder block by the contact between the cone of the connecting rod and the inner wall of the plunger. Timing gear 5 ensures that the rotation of transmission shaft 9 and cylinder block 3 is fully synchronized. The angle between the connecting rod axis and the cylinder bore axis can be designed to be very small, which greatly reduces the lateral force on the plunger and the cylinder block, so that the friction loss between the plunger and the cylinder bore is very small, and the piston ring on the plunger reduces the internal leakage of the pump. Therefore, compared with swash plate axial piston motor, swash plate motor can have a larger cylinder body swing angle. The maximum swash plate angle of swash plate motor is about 20 ° while the maximum swash plate angle of swash shaft motor is 25 ° to 28 ° and the maximum swash angle of new tapered piston motor can reach 40 ° (for example, Parker F1L / FL2 series bent shaft piston motor). Therefore, the swash shaft motor with the same cylinder hole diameter has a compact structure The new type motor will have a larger displacement. The efficiency of swash shaft motor is slightly higher than that of swash plate motor, and higher speed is allowed. But the variable of swash shaft motor depends on the swing cylinder, so the volume of swash shaft motor is large. It needs to overcome the larger inertia moment when it changes quickly, and the dynamic response is slower than that of swash plate motor. The internal structure and shape of the inclined shaft type hydraulic motor are the same as those of the same series of inclined shaft type hydraulic pumps, such as the physical shape of a2fm series inclined shaft type quantitative axial piston motor and a2fo series inclined shaft type quantitative axial piston pump.