Created on:2021-06-15 15:20

Working principle of gear motor

(2) Working principle of multi gear involute external gear motor multi gear motor can increase the output torque. This kind of motor is usually composed of several idling gears and a torque output gear. The idling gears are evenly distributed around the torque output gear, and the torque output gear is larger than the idling gear [but the three gear motor generally makes the gear the same size, as shown in Figure B (a)]. Figure B (b) shows a four gear hydraulic motor. The torque output gear is connected with the output shaft to amplify the torque generated by the hydraulic pressure of the idle gear. At this time, the motor shell (or front and back cover) is provided with corresponding oil inlet and oil return ports, which are respectively connected with the high-pressure oil pipe and the oil return pipe. Some motors have as many as 11 gears. When the working pressure difference △ P = 1ompa and the speed is 2 ≤ 100r / min, the output torque can reach 21000n · M.


(3) The working principle of cycloid internal gear motor cycloid internal gear motor is a multi-point contact gear motor, also known as cycloid rotor motor (referred to as cycloid motor). Cycloid internal gear motor is divided into two types: internal and external rotor type and planetary rotor type. The latter can also be classified in more detail according to the given structural form and distribution mode.

① The inner and outer rotor cycloid motor is almost the same as the inner and outer rotor cycloid pump, but has the following differences.

a. In order to ensure higher starting torque, floating compensation side plate structure is often not used in medium and high pressure, but the method of improving machining accuracy and reducing axial clearance (generally 0.012mm, some even 0.005mm) is used to obtain higher volumetric efficiency.

b. There are higher requirements for the size and precision of parts.

c. In addition to making the structure of the side plate completely symmetrical, two one-way leakage valves are also used to ensure that the leakage oil can be led to the oil return port in both forward and reverse directions.


② The working principle of this kind of motor is based on cycloid pin tooth internal meshing planetary gear transmission, and its working principle is shown in Figure C. The tooth profile of internal gear (i.e. stator) 2 (i.e. pin tooth) is composed of arc with diameter D; the tooth profile of pinion (i.e. rotor) 1 is the conjugate curve of arc, i.e. the equidistant curve of arc center track a (the whole short epicycloid). There is eccentricity e between rotor center O1 and stator center O2. When the tooth number difference between the two wheels is 1, all the teeth of the two wheels can mesh and form Z2 (number of stator pin teeth) independent sealing cavities with variable volume. When used as motors, the larger volume of these sealing cavities is filled with high pressure oil through the oil distribution mechanism (such as the distribution shaft, whose external shape is shown in Fig. d) to make the motor rotor rotate. Other sealing cavities with smaller volume discharge low pressure oil through oil distribution mechanism. This cycle, hydraulic motor continuous work, output torque and speed. The cycloid motor usually adopts 6-7 or 8-9 teeth meshing. This paper takes 6 ~ 7 teeth meshing (the number of rotor teeth is Z1 = 6, the number of stator teeth is Z2 = 7) as an example to illustrate its flow distribution principle. As shown in Figure e, the teeth of two phases are meshed to form 22 sealed cavities. Under the action of pressure oil, when the rotor rotates around its own axis O1, the rotor center O1 also revolves around the stator center O2 at high speed in reverse direction (when the rotor revolves, that is, when the rotor rolls along the stator, its oil suction and pressure chambers change constantly, but always take the connecting line O1O2 as the boundary), which is divided into two chambers. The oil suction chamber is when the volume between teeth on one side increases, and the oil discharge chamber is when the volume between teeth on the other side decreases. Rotate one revolution (at this time, the volume between the teeth completes one oil inlet and return cycle), rotate one tooth in reverse direction, that is, the rotor rotates one revolution only when it rotates Z1 revolution. The speed ratio of revolution and rotation is I = - z1:1. The rotation motion of the rotor is transmitted to the output shaft through the spline coupling (not shown in the figure) and rotates synchronously with the rotation of the connecting line 0102 (when the rotor rotates 1 / Z1 counterclockwise, that is, rotates one tooth, the high-pressure chamber rotates clockwise in the revolution direction for one circle), that is, the high-pressure chamber rotates (5, 6, 7) → (6, 7, 1) → (7, 1, 2) → (1, 2, 3) → (5,6,7). The continuous rotation of the high pressure cavity makes the rotor and the output axis rotate continuously. If you change the direction of oil in and out of the motor, the rotation direction of the motor output shaft will also change.


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