Product Introduction

A hydraulic coupling is a mechanical device that transfers rotational speed using a liquid medium. It connects the driven input shaft end to the original driving mechanism and the driven output shaft end to the load shaft end. By adjusting the pressure of the liquid medium, the rotational speed of the output shaft can be altered. In an ideal state, as the pressure approaches infinity, the output speed equals the input speed, similar to a rigid coupling. When 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 power control and speed regulation principle of the hydraulic coupling, as well as its efficiency, are based on its aforementioned characteristics. The hydraulic coupler is an energy-consuming mechanical speed regulating device; the deeper the speed regulation (the lower the speed), the greater the loss. This is especially true for constant torque loads, where the unchanged input power of the original transmission results in a proportional increase in loss power as the speed decreases. For loads like fans and pumps, where the load torque varies with the square of the speed, the input power of the original transmission decreases at a rate proportional to the square of the speed, resulting in slightly less loss power. However, the output power decreases at a cubic rate of the speed, so the speed regulation efficiency is still low. The speed regulation efficiency curve of the hydraulic coupling shows an average efficiency of around 50%. A non-rigid coupling that uses a liquid as the working medium, also known as a hydraulic coupling.

Product Actual Photos

Product Features

The impeller and turbine of a hydraulic coupling form a sealed working chamber that allows for the circulating flow of liquid. The impeller is mounted on the input shaft, while the turbine is mounted on the output shaft. As the power unit (internal combustion engine, electric motor, etc.) rotates the input shaft, the liquid is ejected by the centrifugal impeller. This high-speed liquid, upon entering the turbine, drives it to rotate and transfers the energy obtained from the impeller to the output shaft. The liquid then returns to the impeller, creating a continuous cycle. The hydraulic coupling transmits torque by changing the momentum moment through the interaction between the liquid and the blades of the impeller and turbine. Its output torque is equal to the input torque minus the friction torque, hence its output torque is always less than the input torque. The input and output shafts of the hydraulic coupling are connected by the liquid, with no rigid connections between the working components. The characteristics of the hydraulic coupling include: the ability to eliminate shock and vibration; the output speed is lower than the input speed, and the speed difference between the two shafts increases with the load; good overload protection and starting performance, allowing the input shaft to continue rotating even when the load is too great and the shaft stops, preventing damage to the power unit; when the load decreases, the output shaft speed increases until it approaches the input shaft speed. The transmission efficiency of the hydraulic coupling is equal to 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 coupling can achieve higher efficiency when the normal operating speed ratio is above 0.95. The characteristics of the hydraulic coupling vary due to differences in the shape of the working chamber and the impeller and turbine. If the oil in the hydraulic coupling is drained, the coupling is disengaged, serving as a clutch.