Product Description

A hydraulic coupler is a mechanical device that uses a liquid medium to transmit rotational speed. Its driving input shaft is connected to the original driving mechanism, while the driven output shaft is connected 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, similar to a rigid coupling. As the pressure decreases, the output speed correspondingly decreases. By continuously changing the medium pressure, the output speed can be infinitely adjusted below the input speed. The principle of power control and speed regulation of the hydraulic coupler, as well as its efficiency, is based on the aforementioned characteristics. A hydraulic coupler is a type of mechanical speed regulating device that consumes energy. 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, as 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 less loss power. However, the output power decreases with the cube of the speed, and the speed regulation efficiency is still very low. The speed regulation efficiency curve of the hydraulic coupler 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.

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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 source (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, transferring 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 the change in momentum due to 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 hydraulic coupling is characterized by its 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; it has good overload protection and starting performance, allowing the input shaft to continue rotating even when the load is too high and the shaft stops, preventing damage to the power source; 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 the different shapes 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.