Working principle of continuously variable transmission mechanism of grain combine harvester

Author:guanjie Time:2024-04-25 10:05:08

The continuously variable transmission mechanism of the grain combine harvester consists of a driving wheel, a driven wheel, a belt, a continuously variable transmission cylinder head and a hydraulic pipeline. The specific working principle is as follows:

(1) Principle of reducing the speed of the driving wheel transmission shaft
    When the speed reduction button is pressed in the cab, the pressure is increased under the action of the solenoid valve to push the hydraulic oil through the continuously variable transmission cylinder head, from the oil outlet A of the transmission shaft into the oil chamber B, and then through the oil cylinder plunger. The oil outlet B enters the oil chamber C. After the hydraulic oil enters the oil chamber C, it will push the driving wheel plate to move in the direction of the driving wheel fixed plate, so that the effective diameter of the driving wheel gradually becomes larger, while the length of the speed change belt is fixed. , when the diameter of the driving wheel becomes larger under the action of hydraulic oil, the moving plate of the driven wheel will slide on the sliding sleeve and gradually move away from the fixed plate of the driven wheel through the pulling force of the speed change belt. When the pulling force of the compression spring is greater than the elastic force, Shortened by pressure, the effective diameter gradually decreases, and the rotation speed of the drive shaft gradually decreases.

(2) Principle of increasing the speed of driving wheel drive shaft
    When the speed change button with increased speed is pressed in the cab again, the pressure is released under the action of the solenoid valve. At this time, the active wheel disc is under the pulling force of the speed change belt, and the hydraulic oil in the oil chamber C is lower than the speed of the speed change belt. Under the condition of tension, the flow backflows, the active rotating disc moves away from the fixed plate, and the effective diameter gradually becomes smaller, while the passive rotating disc has been affected by the elastic force of the compression spring before. At this time, the pulling force of the passive rotating disc by the speed change belt is less than the elastic force of the spring, and the passive rotating disc Under the elastic force of the compression spring, the moving plate of the driven wheel moves toward the fixed plate. The effective diameter of the driven wheel gradually becomes larger, and the speed of the driving wheel transmission shaft will gradually increase. At this time, the driving wheel transmission plate reaches Continuously variable transmission.