1) The filter of the hydraulic oil cylinder is blocked by dirt and cannot play the role of filtering oil: use a clean cleaning oil to remove the dirt from the filter.
2) The oil level is insufficient, the oil suction position is too high, and the oil suction pipe is exposed to the oil surface: add oil to the oil standard position and lower the oil suction position.
3) There are no paper pads on both sides of the pump body and the pump cover; the pump body and the pump cover are not vertically sealed: air is sucked during rotation: the paper pad is added between the pump body and the pump cover; The verticality error of the body and the pump cover does not exceed 0.005mm. Tighten the connection between the pump body and the pump cover without leakage.
4) The active shaft of the hydraulic cylinder is not concentric with the motor coupling, and there is twist friction: adjust the concentricity of the pump and motor coupling so that the error does not exceed 0.2mm.
5) The meshing precision of the hydraulic cylinder gear is not enough: the gear grind precision of the grind gear.
6) The oil seal skeleton of the hydraulic cylinder shaft falls off and the pump body is not sealed: replace the qualified pump shaft oil seal.