Effects of the cross angle on output characteristics and tilting behaviour for 750 mL/r axial piston pumps

Abstract

Large displacement axial piston pumps (>500 mL/r) are the core power components of large construction machineries' hydraulic system. The demand for higher power in large construction machinery is increasing. High pressure and large displacement are the primary areas of focus for enhancing the power of piston pumps. However, this may exacerbate issues with the pumps' output characteristics, such as flow or pressure pulsation and leakage. This paper uses a cross angle of the swash plate to optimize the pulsation and leakage for the 750 mL/r axial piston pumps. Piston and cylinder dynamics affect flow and pressure pulsations, and leakage is related to cylinder tilting behaviour. The pumps’ flow distribution, kinematics and dynamics of the piston and cylinder, output flow and pressure are analysed. A virtual prototype is built based on the rigid-flexible-hydraulic coupling model. The oil film flexible body of the valve plate pair is added. The maximum principal stress and strain of the oil film flexible body are used as indicators of tilting behaviour. Effects of the cross angle on output characteristics and tilting behaviour are investigated through the numerical solution. Results show that the cross angle of −0.5° can effectively reduce the pressure pulsation rate by 0.89% and the flow pulsation rate by 3.77% while optimizing the tilting behaviour of the cylinder. In addition, the cylinder’s tilting behaviour is verified by the wear detection on the valve plate surface.

Keywords

• Large displacement axial piston pump
• Cross angle
• Valve plate pair
• Flow pulsation
• Cylinder tilting behaviour