Hydraulic motor is also known as the oil motor, mainly used in injection molding machinery, ships, helicoid hydraulic motor, engineering machinery, construction machinery, coal mine machinery, mining machinery, metallurgical machinery, ship machinery, petrochemical industry, port machinery.
High speed motor gear motor has small volume, light weight, simple structure, good manufacturability, is not sensitive to oil pollution, impact resistance and inertia small. Faults are large torque ripple, low efficiency, small starting torque and poor stability of low speed.
From the point of view of energy conversion, reversible hydraulic pump and hydraulic motor works of hydraulic components, to any kind of hydraulic pump liquid input work, can make the working condition of hydraulic motor. Conversely, when the spindle driven by external torque hydraulic motor rotates, also can become the working condition of hydraulic pump. Because they have the same basic structure elements, airtight and can cycle change volume and corresponding oil distribution agencies.
However, because of the hydraulic motor and pump working condition is different, their performance is different also, so the same type of hydraulic motor and hydraulic pump, there are still many hydraulic power tong. First hydraulic motor should be able to positive and reverse, and thus requires its internal structure symmetry; Hydraulic motor speed range need enough, especially for its minimum steady speed has certain requirements.
As a result, it usually adopts rolling bearing or static pressure sliding bearing. Second hydraulic motor due to the input pressure oil under the condition of work, so don't need to have self priming capacity, but needs certain initial sealing, can provide the necessary starting torque. Because of these differences, makes the hydraulic motor and hydraulic pumps are similar in the structure, work but can not be reversible.
Hydraulic motor according to its structure type of education can be divided into gear, vane, plunger, and other types. According to the rated speed of hydraulic motor divided into two categories: high speed and low speed. Rated speed higher than 500 r/min belongs to high speed hydraulic motor, rated speed below 500 r/min belongs to low speed hydraulic motor. High speed basic type of hydraulic motor with gear, screw, vane and axial plunger type, etc. They are the main characteristics of high speed, moment of inertia of small, easy to start and brake and regulating speed regulation and directional sensitivity.
Usually high speed hydraulic motor output torque is so called high speed small torque hydraulic motor. Low speed hydraulic motor is the basic pattern of the radial plunger, moreover in axial plunger, vane, and also has a low speed in the gear stuffing box, the main characteristics of hydraulic motor at low speed are large displacement, large volume low speed sometimes up to a few turn even zero several revolutions per minute and therefore can be directly connected to the working mechanism; Don't need a speed reducer, transmission mechanism was simplified, usually at low speed hydraulic motor output torque is bigger, so is also known as low speed high torque hydraulic motor.
Due to the pressure oil, unbalanced force make the rotor torque is produced. Vane hydraulic motor output torque and displacement of hydraulic motor and hydraulic motor oil in and out of the mouth, the pressure difference between the speed determined by the input to the flow of hydraulic motor size. Due to the hydraulic motor to generally positive negative, so vane hydraulic motor blade radial placed. In order to make the blade root pressure on oil, always in the back, pressure oil cavity ordinary check valve shall be set up on the path of blade root, in order to ensure the vane hydraulic motor can normal boot after pressure oil factory, must make the top and the stator blade surface close contact, to ensure a good seal, therefore the preloaded spring shall be set up at the blade root. Vane hydraulic motor moment of inertia of small volume, small, and can be applied to the occasion of the reversing frequency. But larger leakage and instability while working at low speed. So rotary table hydraulic motor is generally used in high speed, small torque and motion sensitivity required.
The radial plunger
Working principle of the radial piston hydraulic motor, when the oil in the pressure of oil distribution of fixed axis 4 window into the bottom of the piston within the cylinder block, piston, protruding from the tightly against the stator lining, because of the stator and cylinder body is eccentricity. In the plunger contact with the stator, the stator of reaction for the plunger. Force can be decomposed into and two component. Role when the oil pressure in the bottom of the plunger is p, plunger diameter d, the Angle between the force and for X, produce a torque force on cylinder block, cylinder body rotation. Cylinder body travel through the end of the connection shaft to the output torque and rotational speed.
The single acting type connecting rod radial piston motor
As shown in figure , connecting rod motor figure, axial thrust hydraulic motor as shown in figure, the pentagon radial motor assembly animation for single acting type connecting rod radial piston motor working principle diagram, its exterior five-pointed star shaped. The motor by the shell valve shaft, crankshaft connecting rod, piston and parts such as eccentric.
Advantages: simple structure, drill pipe joint.
Disadvantages: big volume, weight, and torque pulsation, poor stability at low speed.
The more curve in piston motor
The motor by the valve shaft of the beam, and plunger cylinder body roller output shaft of the stator. This kind of motor displacement is relatively single stroke motor increases times. The equivalent of plunger. Because of increased equivalent number of plunger, under the same working pressure, output torque increase, decrease the torque pulsation rate. Sometimes the motor to make more plunger, plunger several more, further increases in output torque, torque pulsation rate further reduced. So the motor can make large displacement, and can be under the low speed into smooth operation. Since motors need two-way rotating, so the blade groove is radial layout. The plunger type high speed hydraulic motor
Plunger type axial type high speed hydraulic motors are generally.