Monitoring the Condition of Loaded Modern Water Hydraulic Axial Piston Motor and Cylinder

Recent advancement in technology has produced materials that can withstand highly corrosive environment and lubrication-free materials for water hydraulic components. With precision machining becoming possible, very close tolerances can now be achieved to reduce internal leakage due to the low viscosity of water. Many industries are slowly but steadily turning to water hydraulic systems to replace their oil hydraulic systems. The use of water hydraulic systems will increase in future as new applications are found for this technology. As with all systems, the increasing use of water hydraulic systems by more industries will result in the need to monitor and maintain the systems. This paper is concerned with the condition monitoring and fault diagnosis of loaded modern water hydraulic cylinder and axial piston motor. LabVIEW software was used for data acquisition and processing. It provides a graphical programming environment that integrates data acquisition, analysis and presentation in one system for effective analysis. Likely real-life faults were simulated on the actuator's internal components. Some results such as the vibration signatures and amplitude spectra of the water hydraulic actuators under different operating conditions of simulated loads and speeds are presented and discussed. The results show that there is a distinctive variation in vibration signals, flow rate and average stroking duration with increase in loads for both actuators. The actuators were also operated to capture their unique vibration signals in their faulty states and the results compared with reference signatures of the same actuators when they were in their new or healthy states. The results imply that LabVIEW software can be written to set warning levels and trigger an alarm when a fault is impending.