Maintenance of combine -- disassembly and assembly of double gear pump

Maintenance of combine -- disassembly and assembly of double gear pump

Double gear pump is used in the hydraulic system of a 1605 grain combine. Attention should be paid to the following items during disassembly.

(1) Precautions for disassembly

① After the hydraulic pump is removed from the body, the plastic cover or plug should be used to plug the oil pipe joint and the opening of the pump immediately to prevent dirt from entering the hydraulic system. Then, clean the outside of the pump with clean diesel or gasoline.

② In order to ensure the correct assembly after disassembly, mark "X" or "V" on the front cover, central pump body, pump shell and rear cover with waste saw blade or similar tools along the axial direction of the pump before disassembly.

③ Hydraulic pump is a precision component, to ensure that the whole pump in the disassembly process without dust and impurities, can not use rags, cotton yarn to wipe parts, parts after cleaning with compressed air blow dry or air dry.

④ When the shaft pump needs to be clamped on the vise, pay attention not to clamp on the central pump body to prevent deformation.

⑤ When disassembling the hydraulic pump, first remove 8 bolts with special tools, and then knock the head of the rotating shaft with a wooden stick to disassemble the gear pump. Pay attention not to use too much force when hitting the driving shaft. Tap gently and knock several times more. The disassembly sequence is shown in Figure E.

(2) Installation precautions

① Check the wear condition of all parts, and pay attention to that the lubrication groove of the shaft sleeve must be on one side of the high-pressure chamber, and the shaft sleeve cannot escape from the seat hole. Use high-quality emery cloth to wipe off all scratches and burrs, and pay attention to cleaning after treatment.

② During installation, all vulnerable parts must be renewed, including copper side plate, phenolic gasket, protective gasket, V-shaped rubber gasket, O-ring and shaft end oil seal.

③ Lubricate all parts with engine oil or hydraulic oil before assembly.

④ Install the V-shaped rubber gasket in the concave part of the front cover and pump housing, and make the lip downward. When installing, be careful and patient, and ensure that the lip is not reversed. All the lips should be placed in the groove, and no flanging is allowed.

⑤ Assemble the parts according to the original marking, and the installation sequence is opposite to the disassembly sequence. The half moon cavity of the center pump body should not face the front cover, but should face the pump shell. The O-ring installed in the pump housing groove must be flat without distortion.

⑥ After installing all parts, tighten them with bolts, and the tightening torque is 37 ~ 40n · M.

⑦ Coat the oil seal of the rotating shaft with engine oil or hydraulic oil, and carefully install it on the driving gear shaft with the sealing lip facing inward. Use a wooden hammer shaft to knock to position the oil seal. Pay attention not to install the sealing lip reversely or damage the oil seal.

⑧ After the hydraulic pump is assembled, install the drive pulley. There will be some resistance when the pulley is rotated by hand, but it should be able to rotate freely after a few turns.

⑨ Install the hydraulic pump on the body, oil pipe and hose on the pump, add clean hydraulic oil to the pump, connect the oil pipe flange, and ensure no air entering before installing the flange. Start the engine and rotate at medium speed for 3 min without operating the hydraulic control handle; At the same speed, operate the control handle for about 3 minutes to build up the pressure; Then increase the throttle to the maximum speed, operate the control handle for 3min, shut down the engine, and check the gear pump for oil leakage.