單項(xiàng)選擇題
A.decreased clearances between rotating parts B.decreased slippage to the suction side of the pump C.air binding in the discharge ports D.erosion and excessive wear
A.a shortage of refrigerant in the system B.air in the system C.an accumulation of liquid refrigerant in the crankcase D.a shortage of oil in the crankcase
A.ram relief valves bypass oil to stop rudder movement B.six-way valve shifts to the neutral flow position C.steering pump electric motor is de - energized by the transfer switch D.follow-up gear takes the hydraulic pump off stroke
A.maintain a preset pressure on the line B.closely regulate the amount of flow C.relieve excessive pressure on the line D.allow flow in one direction only
A.insufficient load B.excessively high oil viscosity C.relief-valve pressure setting too high D.reservoir level being maintained two inches above normal
A.a defective or broken high pressure un-loader B.a loose valve plate C.excessive overload D.no compression
A.regulating the oil flow with the six-way valve B.moving the automatic differential valve C.moving the receiving tele-motor which regulates the two-way valve D.varying the angle of a tilting box or eccentricity of a floating ring
A.Pour point B.Cloud point C.Vacuum D.Pressure
A.set for maximum torque B.on the purge and vent stroke C.in the neutral position D.rotating backwards
A.frames B.joiners C.longitudinals D.knees
A.pump bearings in poor condition B.excessively worn actuator-piston packing C.broken directional control valve centering springs D.low hydraulic oil viscosity
微信掃一掃關(guān)注公眾號(hào)后聯(lián)系客服
微信掃碼免費(fèi)搜題
