Hydrostatic system failure cause analysis and judgment method

Dongfeng 'locomotive cooling fan (hereinafter referred to as "fan") using hydrostatic transmission, two fan drive exactly the same. Each system by hydrostatic pumps, temperature control valve (hereinafter referred to as "control valve"), safety valves, hydrostatic motors, heat exchangers, tanks and other pipe fittings components (Figure 1). Hydrostatic system in the event of failure can not be guaranteed in the best diesel oil, Hydraulic adapters water temperature range of work, serious and even endanger the safe operation of the locomotive. Hydrostatic system failures are ultimately reflected in the common fan does not turn or speed is not normal, resulting in oil, water temperature is too high influence on the engine to work properly. (Water temperature 74 ± 2 ℃, oil temperature 65 ± 2 ℃) can not be fully closed valve port cover. (4) initiating thermostatic temperature higher than the temperature required the initiating. Thus, when oil, water temperature is a temperature within a predetermined range value, the fan speed can not achieve appropriate rated speed. LZ safety valve failure will lead to the failure of the safety valve opening pressure is lower than the high pressure of work pressure. Should open when the oil return passages open, so can not afford to establish normal oil pressure, and thus the fan speed to reach its rated speed .