Product Description

A hydraulic coupler is a mechanical device that transfers rotational speed using a liquid medium. Its active input shaft end is connected to the original driving machine, and the passive output shaft end is connected to the load shaft end. By adjusting the pressure of the liquid medium, the rotational speed of the output shaft can be changed. In an ideal state, when the pressure approaches infinity, the output rotational speed is equal to the input rotational speed, which is equivalent to a rigid coupling. As the pressure decreases, the output rotational speed decreases accordingly. 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 for a hydraulic coupler, as well as its efficiency, is based on the aforementioned characteristics. A hydraulic coupler is a power-consuming type of mechanical speed regulating 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 unchanged, 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, so the speed regulation efficiency is still very low. The speed regulation efficiency curve of a hydraulic coupler has an average efficiency of around 50%. A non-rigid coupling that uses liquid as the working medium, also known as a hydraulic coupling.

Product Real Photos

Product Features

The pump wheel and turbine of a hydraulic coupling form a sealed working chamber that allows for circulating liquid flow. The pump wheel is mounted on the input shaft, while the turbine is mounted on the output shaft. As the prime mover (internal combustion engine, electric motor, etc.) rotates the input shaft, the liquid is ejected by the centrifugal pump wheel. This high-speed liquid, upon entering the turbine, drives it to rotate and transfers the energy obtained from the pump wheel to the output shaft. The liquid then returns to the pump wheel, creating a continuous flow. The hydraulic coupling transmits torque by the change in momentum caused by the interaction of the liquid with the pump wheel and turbine blades. Its output torque is equal to the input torque minus the friction torque, hence it is always less than the input torque. The input and output shafts of the hydraulic coupling are connected by the liquid, with no rigid connection between the working components. The hydraulic coupling's features include: it can eliminate shocks and vibrations; the output speed is lower than the input speed, and the speed difference between the two shafts increases with the load; it has good overload protection and starting performance; when the load is too high and the shaft stops, the input shaft can still rotate without damaging the prime mover; and as the load decreases, the output shaft speed increases until it approaches the input shaft speed. The transmission efficiency of the hydraulic coupling is the ratio of the product of the output shaft speed and output torque (output power) to the product of the input shaft speed and 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 the different shapes of the working chamber and the pump wheel and turbine. If the oil in the hydraulic coupling is drained, the coupling is disengaged and can act as a clutch.