Variable displacement pumps are a type of hydraulic pump that can vary the displacement or flow rate of fluid being pumped. This means that the pump can change the amount of fluid it pumps per revolution or stroke, depending on the demand of the system.
There are two main types of variable displacement pumps: axial piston and bent axis. In an axial piston pump, the displacement is changed by varying the angle of the pistons in relation to the drive shaft. This is achieved through a swash plate mechanism. In a bent axis pump, the displacement is changed by varying the angle of the wobble plate, which is connected to the pistons.