How do hydraulic motor manufacturers conduct diagnostics for marine hydraulic motors?

Marine vessels have employed hydraulic control systems for hatch industrial equipment for nearly a century. With advancements in key hydraulic press technologies, hydraulic control systems have been further applied to other aspects of naval weaponry, such as automatic mooring trials, ship stabilizing fins, and adjustable-pitch marine propeller drive system adjustment mechanisms. If these hydraulic drive systems fail, they will severely impact maritime transportation operations and increase operational costs for waterway transport enterprises. According to incomplete data, nearly 30% of hydraulic control system failures are caused by faults in double-shaft hydraulic motors. Therefore, understanding the types and patterns of hydraulic motor failures is of critical importance for diagnosing and repairing faults in marine hydraulic control systems. The following discusses common failures in marine hydraulic motors.

Common Failures in Marine Hydraulic Motors

Different operational conditions require hydraulic control systems to utilize distinct types of hydraulic motors. Among them, single-acting radial piston marine crane hydraulic motors have a simpler structure and are suitable for applications with lower requirements for low-speed stability. Double-swashplate radial piston hydraulic motors offer a wider efficiency range and maintain good low-speed stability. When large torque output and excellent low-speed stability are required, internal curve multi-acting radial piston hydraulic motors are generally selected.

Under normal operating conditions, the hydraulic motor in a hydraulic control system should operate smoothly without abnormal noises. Otherwise, it indicates improper installation or defects in components such as the motor's rotor, vanes, or torsion springs. Due to the harsh working environment and heavy loads, marine hydraulic motors are prone to various failures after a period of use. These failures manifest in diverse ways, with degraded low-speed stability (wear) being the most common issue in marine hydraulic motors. This typically occurs due to oil contamination. The working conditions of marine hydraulic control systems are extremely severe, making it easy for various contaminants to mix into the oil, causing premature wear of marine radial piston hydraulic motor components and irregular increases in oil leakage, ultimately resulting in a sharp decline in the motor's low-speed stability. Oil contamination poses significant harm to the entire hydraulic control system, damaging hydraulic pumps and causing irregular pulses in oil supply volume and pressure, which similarly degrade the low-speed stability of hydraulic motors. Effective oil pollution control and purification are crucial tasks for marine hydraulic control systems. Additionally, after a period of use, a decrease in the original operating pump discharge pressure may also affect the motor's low-speed stability. In such cases, adjusting the pump discharge pressure and adopting appropriate pump discharge backpressure can be effective solutions.