Product Introduction

A hydraulic coupler is a mechanical device that transmits rotational speed using a liquid medium. It connects the driven input shaft to the original driving machine and the driven output shaft to the load shaft. By adjusting the pressure of the liquid medium, the rotational speed of the output shaft can be changed. In an ideal state, as the pressure approaches infinity, the output speed equals the input speed, akin to a rigid coupling. As the pressure decreases, the output speed correspondingly drops. Continuously changing the medium pressure allows for a stepless adjustment of the output speed below the input speed. The principle of power control and speed regulation, as well as the efficiency of the hydraulic coupler, are based on its aforementioned characteristics. The hydraulic coupler is a power-consuming mechanical speed regulation device; the deeper the speed regulation (the lower the speed), the greater the loss, especially for constant torque loads. Since the original driving input power remains constant, the loss power increases proportionally with the speed loss. For loads like fans and pumps, where the load torque varies with the square of the speed, the original driving input power decreases with the square of the speed, resulting in relatively smaller loss power. However, the output power decreases with the cube of the speed, and the speed regulation efficiency remains low. The speed regulation efficiency curve of the hydraulic coupler shows an average efficiency of around 50%. A non-rigid coupling that uses liquid as the working medium, also known as a hydraulic coupling.

Product Actual Photos

Product Features

The pump wheel and turbine of a hydraulic coupler form a sealed working chamber that allows for the cyclic flow of fluid. The pump wheel is mounted on the input shaft, while the turbine is mounted on the output shaft. As the power unit (such as an internal combustion engine or electric motor) drives the input shaft to rotate, the fluid is ejected by the centrifugal pump wheel. This high-speed fluid, upon entering the turbine, imparts rotation and transfers the energy obtained from the pump wheel to the output shaft. The fluid then returns to the pump wheel, creating a continuous flow. The hydraulic coupler transmits torque by changing the momentum of the fluid interacting with the blades of the pump wheel and turbine. Its output torque is equal to the input torque minus the frictional torque, hence it is always less than the input torque. The input and output shafts of the hydraulic coupler are connected by the fluid, with no rigid connections between the working components. The hydraulic coupler features the ability to eliminate shocks and vibrations; an output speed lower than the input speed, with the speed difference between the two shafts increasing with load; good overload protection and starting performance, allowing the input shaft to continue rotating even when the load is too great and the power unit stops, thus preventing damage to the power unit; and as the load decreases, the output shaft speed increases until it approaches the input shaft speed. The transmission efficiency of the hydraulic coupler is the ratio of the output shaft speed multiplied by the output torque (output power) to the input shaft speed multiplied by the input torque (input power). Generally, a hydraulic coupler can achieve high efficiency when the rotational speed ratio is above 0.95 under normal operating conditions. The characteristics of the hydraulic coupler vary due to differences in the shape of the working chamber and the pump wheel and turbine. If the fluid in the hydraulic coupler is drained, the coupler is disengaged and can act as a clutch.