Diaphragm Pump Inspection 1. Disassembly and Assembly 1. Disassembly of Diaphragm Metering Pump Cylinder Components Move the plunger to the mid-stroke position and unscrew the plunger from the crosshead. After removing the suction pipe flange and the nut connected between the pump bracket and the cylinder part, remove the diaphragm cylinder part from the base and remove all the parts in the pump in the following order. Figure 1 Mesh position of worm gear and worm (2) There should be no scratches or bumps on the journal when reinstalling the worm and plunger seals. And apply a layer of silicon grease on the sealing surface. Use 0.3~0.5mm insulation paper roll to guide on the journal. Push the oil seal into the insulation paper after pulling it in. Do not use a metal block with sharp corners to avoid damaging the oil seal. Lips affect the effectiveness of the seal. On-Line Film Thickness Measurement Systems Film Thickness Measurement Systems,On-line Thickness Measurement ,Thickness Measurement System,film Thickness gauge CHANGLONGXING SCIENCE & TECHNOLOGY (SHENZHEN) CO.,LTD , https://www.clxmachinery.com
(1) Remove the safety valve or safety valve, pull out the plunger, unscrew the packing gland bolts, remove the packing gland, and remove the packing and plunger sleeve.
(2) Remove the suction pipe pressure plate, remove the valve sleeve, the limiting piece, the valve ball or the spring and the valve in turn.
(3) Remove the cylinder head, remove the diaphragm, pressure ring, positioning pin and so on.
2. Disassembly of the gear box (1) The lubricant in the gear box is drained from the rear and side plugs, and the cover at the rear end of the box is removed.
(2) Remove the motor, remove the coupling, unscrew the worm bearing compression nut, and remove the bearing cover, bearing, worm, and oil pump from the transmission case.
(3) Open the adjustment box cover, remove the compression nut of the adjustment box, turn the adjustment dial counterclockwise to make the adjustment screw rod withdraw from the adjustment nut, remove the adjustment box, and then take the adjustment screw rod part from the upper sleeve , Then remove the upper sleeve from the transmission case.
(4) Remove the pump bracket compression nut, remove the pump bracket from the transmission case, open the upper cover of the transmission case, and remove the crosshead pin from the case.
(5) Take the N-axis and the eccentric block, connecting rod, eccentric block, etc. on the N-axis and take it out of the transmission box. The basic components are removed in the following order: Remove the adjustment nut, and then from the N-axis Remove the eccentric block upper ring, bearings and washers; pull out the eccentric block sleeve on the eccentric block, remove the needle roller and the eccentric block; turn the transmission box body, remove the transmission box body bearing cap, the worm gear, under The sleeve, the bearing, etc. are taken out from the transmission case at the same time, and the lower sleeve can be taken out one by one.
3, the assembly sequence Before the gearbox assembly cleaning and inspection of all parts, for those who have worn and can not be repaired should be replaced with new parts. According to the order of disassembly, when counterclockwise is used to install the multiple transmission section, the following points should be noted.
(1) When reassembling or replacing the new worm and worm gear, pay attention to re-adjust the meshing position of the worm gear and the worm (Fig. 1). The adjustment method is to apply a thin layer of red dan on the worm wheel working tooth surface, rotate the worm shaft by hand and observe the position of the meshing point. By increasing or decreasing the number of shims, the meshing point can reach the correct position. 
(3) The adjustment of the gap between the worm and the worm wheel can be properly adjusted by adding or subtracting the number of spacers. If the clearance is too large, the pump operation has impact noise; and if the clearance is too small, turning the adjustment handwheel during operation is more difficult.
(4) The gearbox shall be reassembled in the counterclockwise sequence, and then the coupling shall be checked for rotation. The rotation shall be freely and without any jamming. Rotate the adjusting dial and the rotor motor coupling to adjust the stroke to the zero position, install the adjustment table pointing to the zero position; turn the adjustment dial to adjust the stroke to the specified maximum stroke, and move the crosshead to the forward dead point position.
(5) Because the metering pump is a single pulsating load, the load on the worm gear wear is a drain stroke greater than the suction stroke. Therefore, after the pump has run for 6000 hours, according to the worm gear wear condition, the position of the worm wheel relative to the original assembly can be rotated 180[deg.] around the axis and then mounted back, which can prolong the working life of the worm gear.
(6) Press the piston cylinder component removal procedure and install it counterclockwise on the transmission case, and adjust the tightness of the packing gland bolts. Rotate the coupling to make a trial run. It shall be able to rotate freely without any jamming.
(7) When the multiple pumps are in the rotary centering coupling, pay attention to the even distribution of the phase angles of each pump plunger, especially the same carrier code and the same transmission ratio, the plunger phase angle must be evenly staggered, so as not to over-concentrate the load Stage worms and motors run unfavorably.
Second, parts quality standards and maintenance 1, into the discharge valve Valve seat and valve head should have a good line of fit, the width of the line of 0.25 ~ 2.00mm, and the above can not have rust, pits and other defects. If it does not meet the requirements, a combination of machining and centering can be used to repair. If the corrosion is serious, replace the valve seat.
2, diaphragm Diaphragm should be smooth, no scratches, elasticity meets the requirements.
3, control valve Adjust the pressure valve spool and valve seat tightly matched, kerosene leakage test 5min, leakage does not exceed a drop. According to the damage, it can be processed, centered, or ground. If it cannot be repaired, replace it.
The quality standard and repair method of the oil fill valve are the same as those of the pressure valve.
(4) Pump body The plunger and the guide tube have a dimensional tolerance of H8/g8, a roundness of 0.02 mm, a straightness of 0.02 mm, a surface roughness of not more than Ra0.8 μm, and a surface hardness of 45 to 55 HRC.
Matching shaft diameter and positioning shaft diameter coaxiality is 0.02mm. The maximum grinding amount of the plunger is 0.01D (D is the diameter).
5, guide sleeve Concentricity of the inner diameter and outer diameter of 0.02mm. With the plunger fit dimension tolerance surface is H8/g8. The seal ring should have good elasticity, no aging, cracking, and no scratches on the mating surface of the plunger.
(6) Crankshaft The fitting tolerance of the main journal, crank neck and bearing shell is G7/h6, the roundness is 0.02mm, the straightness is 0.02mm, and the surface roughness is not more than Ra0.8μm. The maximum grinding allowance for the main journal and crank is 0.04 times the diameter.
(7) Crankshaft bush shell No friction and fluffing on the mating surface of the bearing shell. The surface roughness is not more than Ra0.8μm. The guide hole perpendicular to the bearing mating surface is 0.02 mm.
After the combination of the two shaft shells, the coaxiality of the guide holes at both ends is 0.02mm.
(8) Crankshaft watts Dimensional tolerance for fit with bush shell is H7/g6. Dimensional tolerance with crank neck fit is H7/g6, and mating surface roughness is not greater than Ra1.6 um. Bearing shell keyway and positioning key fit size tolerance is H7/g7.
(9) Crankshaft sleeve with the main shaft with the dimensional tolerance of H7/g6, the surface roughness is not greater than Ra1.6μm. The inner diameter and outer diameter are 0.02mm.
(10) The fitting tolerance of the center shaft and sleeve is H7/g6. The roundness is 0.02mm, the straightness is 0.02mm, and the surface roughness is not more than Ra0.8μm. With the journal and positioning journal coaxial coaxiality of 0.01mm. The maximum grinding amount is 0.04 times the diameter.
(11) The surface roughness of the shaft sleeve is not more than Ra1.6μm. The inner diameter and outer diameter are 0.02mm coaxial.