Assembly of gear pump
Assembly of gear pump
Pay attention to the following items when assembling the repaired gear pump.
(1) Remove burrs on all parts by deburring. The sharp edge of the gear shall be blunt with natural oilstone, but it shall not be rounded. The flat ground parts shall be demagnetized. All parts can be put into assembly after being cleaned with kerosene.
(2) The axial clearance of CB-B type is directly controlled by the gear and the pump body. The thickness of the pump body is generally 0.02 ~ 0.03mm wider than the tooth width. It is generally not allowed to add paper pads between the pump body and the front and rear covers during installation, otherwise the axial clearance will be too large and the volumetric efficiency will be reduced. Too small axial clearance is easy to generate heat and reduce mechanical efficiency.
(3) For the oil seal installed on the long shaft on the front cover of CB-B gear pump, its outer end face shall be flush with the flange and shall not be driven too deep to avoid blocking the oil drain channel (see Figure d), resulting in oil trap and oil leakage at the oil seal.
(4) Two locating pin holes of CB-B gear pump are generally used by the manufacturer as the processing process benchmark. During the maintenance and assembly of the gear pump, if the user first hits the locating pin on the three parts of the front and rear covers of the pump body, and then tightens the six compression screws, the problem that the gear can not rotate often occurs. The correct method is to tighten the six compression screws diagonally and crosswise, and turn the long shaft by hand. If there is no difference in weight and the rotation is flexible, then hinge two pin holes and drive in the locating pin.
(5) The pump body of CB-B gear pump is easy to be installed reversely, so special attention must be paid, otherwise it can not absorb oil, and it is easy to flush the framework oil seal over.
(6) The allowable deviation of needle diameter of needle roller bearing shall not exceed 0.003mm, and the allowable deviation of length shall be 0.1mm. The needle roller must be fully filled with the bearing race. It is best to buy a complete set of purchased parts or bearings processed with copper sleeves.
(7) After the gear pump is assembled, if possible, it can be tested on the bench according to the specified technical standards. If not, it must be tested on the main engine before it can be put into use.