1、 connected with the 4pump;b. Remove the nut of pump cover and lift the pump;c. Remove the cover plate of diffuser, check and clean the diffuser and every part of the pump body;d. Remove the impeller nuts, the setting nuts of inducer and seal box, check the impeller, inducer and drive shaft for any d
2、amage and deformation.3.2.2 Speed-up gearboxa. Disassemble the speed-up gearbox, remove the low-speed shaft, intermediate shaft and bearing, and remove the gear oil pump and limit spring, clean and check them;b. Remove the high-speed shaft and the upper and lower bearing bushes, check the journal an
3、d bearing bush for wear and the correct fitting clearance (refer to Table 2);Table 2 mmClearanceType and bearing bushNormal clearance Maximum allowable wear clearanceUpper end bearing bush 0.070.11 0.15LMV-311LMV-331BMP-311 Lower end bearing bush 0.070.11 0.15Upper end bearing bush 0.0550.09 0.13LMV
4、-322Lower end bearing bush 0.070.11 0.15c. The bearing bush shall be free of defects such as ablation, sticking and abrasion damage, The surface roughness of the journal shall not be greater than Ra 0.20 and the depth of groove mark shall not exceed 0.01mm, otherwise it shall be ground or replaced;d
5、. Check the wear of the thrust disc and bearing. The run-out of the end face and radial circle of the thrust disc shall be 0.02mm. For the seriously eroded or defective thrust pad, it shall be replaced;e. The error of linearity of the low, medium and high-speed shaft axes shall be less than 0.01mm;f
6、. K7/h6 shall be adopted for the fitting of high-speed shaft and impeller. The clearance after worn shall not be greater than 0.03mm. Torque wrench shall be used for tightening the fastening bolts of the bearing of high-speed shaft;g. The journal shall be precooled and the gear and rolling bearing s
7、hall be warmed up when assembling shaft, gear and rolling bearing, the temperatures shall be controlled within those specified in Table 3;Table 3 0C5Type of pumpPartLMV/BMP-311LMV-322 LMV-311Gear 190-205 (shall be lower than the tempering temperature)Journal -18Rolling bearing 120h. H7/h6 shall be a
8、dopted for the fitting of the outer diameter of bearing with the bushing, the inner diameter of the bushing after worn shall not be greater than 90.065mm, the radial clearance of the rolling bearing shall not be greater than 0.06mm and the bearing shall rotate smoothly and be free of spots, scars an
9、d burrs;i. The rolling bearings of the low-speed shaft and intermediate shaft shall be installed in position;j. Thoroughly clean the inner oil path and nozzle of the speed-up gearbox, however, it is not allowed to enlarge the bore of the oil nozzle;k. Check that the oil pump is assembled properly af
10、ter completing the assembling of the speed-up gearbox, the correct method is: when pressed down with hand the low-speed shaft shall be elastic, otherwise the pins are not aligned; also, the low-speed shaft can be turned at the coupling to check that the oil pump is running properly. l. The displacem
11、ent of the high-speed shaft is 0.33-0.42mm;m. The surface of the gear shall be free of obvious defects such as pitting, scar and ablation; the engaging of the gear surface shall be greater than 80% and 55% in the direction of width and height respectively. The clearance between gears on the top of e
12、ngagement is 0.20-0.30m (m is the module of gear), the tolerance of parallelism between the two gear shafts shall be less than 0.025mm. n. The rolling bearing, gear and gasket ring shall be installed securely in position;o. Grease shall be applied to the lip of shaft seal when the shaft seal on the motor
