Mechanical seals use mechanical means to transmit power and motion. Mechanical transmission is widely used in mechanical engineering, with various forms, mainly including belt transmission, gear transmission, chain transmission, worm and worm gear transmission, rack and pinion transmission, and screw transmission. Gear transmission can be used in high-power applications with accurate transmission ratios, but generally requires higher manufacturing and installation accuracy. There is also a type of friction transmission that relies on friction between components to transmit power and motion, including belt transmission, rope transmission, and friction wheel transmission.

There are many forms of transmission, but the replacement of mechanical seals is very similar. Before disassembly, it is necessary to confirm that the motor is in maintenance status, unscrew the oil filler plug, and use a suction tube to suck out the lubricating oil in the seal seat cavity. Prepare a workbench and disassembly tools for placing pump parts. Do not randomly place and use them to avoid damaging pump parts.

Disassembling the split coupling: First unscrew the fixed socket head cap screw of the coupling, then gently pull the half of the coupling off the shaft, taking care not to drop it. Then, use a ring wrench to unscrew the pump shaft lifting bolts and blocks, allowing the impeller to slowly sink to the pump body, and then remove the other half of the coupling and remove the pump shaft retaining ring.

Disassembling the mechanical seal: Grasp the seal spring and lift it up along the pump shaft to remove it.

Disassembling and cleaning the bearing seat: First loosen the bearing seat slightly, then use the removal bolts to jack up the bearing seat, and lift it up along the pump shaft to remove it. Then use jet fuel to clean the bearing and seat. Before installation, dry it and apply a small amount of No. 20 mechanical oil for lubrication and protection.

Disassembling the sealing seat: Unscrew the sealing seat compression nut, gently remove the sealing seat and clean it.

Mechanical seal assembly: Apply a layer of clean No. 20 lubricating oil to the mirror surfaces of the moving and stationary rings, and apply lubricating oil to the guide bearing seat. First, gently position the stationary ring and install it into the guide bearing seat, and then apply lubricating oil to the pump shaft. Gently install the moving ring onto the pump shaft. Gently push the sealing ring by hand to ensure that it can expand and contract freely. Note that the anti rotation parts of the moving and stationary rings must be assembled in place.

Coupling installation: Install a retaining ring on the motor shaft head, install half of the coupling, install a stopper on the pump shaft end and in the coupling groove, and tighten the bolts with a ring wrench; Install the other half of the coupling and screw in the socket head cap screw. Inspection requirements for correct installation of the coupling: The upper and lower clearances of the split coupling should be uniform, and the coupling should be manually rotated for a few revolutions to check the flexibility of rotation.