Three major methods of controlling hydraulic clearance in axial piston pumps

In axial piston pumps, hydraulic clearance is a problem that requires special attention. When the flow direction or load conditions change, unexpected clearance or movement may occur between pump components, which may cause system efficiency to decrease, vibration to increase, or even damage. Therefore, controlling hydraulic clearance is essential to maintain smooth operation and precise control of the pump. Here are some common methods of controlling hydraulic clearance:
Preload mechanism: Preload mechanism eliminates or reduces clearance by applying a preload force on the pump components. This can involve the use of springs, hydraulic accumulators, or mechanical elements to generate a constant force to keep the components engaged. By eliminating free clearance, clearance is minimized, thereby improving control and reducing vibration.
Control algorithm: Advanced control algorithms can actively compensate for hydraulic clearance. These algorithms compensate for clearance by monitoring the operating conditions of the pump, including flow, pressure, and load, and adjusting the control signal accordingly. By continuously adjusting the control input, the algorithm can minimize the impact of clearance on pump performance and improve overall control accuracy.
Feedback control: Feedback control systems measure the actual position or pressure of pump components by incorporating position or pressure sensors into the pump system and compare it with the expected value. The feedback signal is then used to adjust the control input, compensating for any detected backlash and maintaining desired performance.