Single Piston Test Bench for Measuring Piston-Bushing-Contacts

  Image of the Single Piston Test Bench

The piston-bush contact is one of the most highly loaded contacts in swash plate machines. The complex friction condition in this contact can be measured at ifas with the single-piston test rig. The kinematic chain in the test rig corresponds to a swash plate machine. The piston is guided in a stationary bushing and driven by the swash plate. This setup allows various sensors to be mounted on the bushing. At the same time, this arrangement with interchangeable bushing carriers allows rapid changeover between different design parameter or material variants.

The piston forces (axial friction force and transverse forces) are supported in a bushing carrier. These forces are transmitted through the force plate to piezoelectric load cells. To avoid a force shunt, the fluid conveyed by the piston is directed to the rotary valve without reaction force by means of a compensation piston. In the piston chamber, the pressure build-up that occurs in hydrostatic displacement units can be realistically simulated. This is achieved with the aid of a synchronized rotary slide valve, which switches between preloaded low pressure and high pressure. The pressure levels are set on the valve block by means of pressure control valves. Thus, the operating modes pump or motor operation can be realized.

  • Pressure: 100-325 bar
  • Speed: 0.1-300 min-1; 500-2750 min-1
  • Fluid temperature: 30-50°C
  • Swashplate angle: 0-20
  • Swivel angle: 0-7,5°.