Hydraulic clutches are equipment drive assemblies that contain hydraulically actuated components for connecting two shafts so that they can either be locked together and spin at the same speed, or decoupled and spin at different speeds. They deliver a higher torque per unit volume than other types of clutches and provide fast response times and smooth engagement. Hydraulic clutches transmit force from one point to another using an incompressible fluid such as oil that powers a piston. Engaging a hydraulic clutch transfers power from an engine to devices such as a transmission and drive wheels. Disengaging a hydraulic clutch stops the power transfer, but allows the engine to continue turning. Hydraulic clutches are self-regulating and require less maintenance than many other systems.