汽车起重机采用的75泵(ZB型,下同)是通过7个柱塞在缸体孔中不断地改变位置(直线运动)来吸油和压缩排油的。当柱塞磨损严重时,其与缸体孔的配合间隙就会增大,且孔径变得很不规则,使泵的压力下降,效率降低,甚至不能使用。在维修中发现,很多旧的75泵还是可以修复的。经过修复的75泵,一般都能再用2-3年。修复的方法可以避繁就 The 75 pump (type ZB) used in truck cranes absorbs and compresses the oil by constantly changing positions (rectilinear motion) of the seven plungers in the cylinder bore. When the plunger wear serious, its cylinder bore with the gap will increase, and the aperture becomes very irregular, so that the pump pressure drop, reduce efficiency, or even can not be used. Found in the repair, many of the old 75 pump can still be repaired. After the repair of 75 pumps, generally can reuse 2-3 years. Repair method can be avoided