Measuring vertical shaft pump shaft bending and adjustment

In this paper, Li Jia pump finishing. The main content of this paper is to analyze and measure the bending degree of the pump shaft of the vertical shaft pump and how to adjust the bent shaft. In the article, the expression can not be applied to every type of pump, the specific problems have to be analyzed.

1. vertical long axis pump shaft bending:

Vertical long axis pump structure is precise, the gap between the moving and static parts is small, the rotor speed is high, the shaft is negative

Load. Therefore, the requirements of the axis is more stringent. Axis of curvature generally does not allow more than 0.02mm, more than 0.04mm should be straight shaft, shaft bending trend will increase the pump rotor flutter, flutter bound to increase the sealing ring and the guide vane bushing clearance, if the gap is too large, will form a vortex, causing water pump vibration. Reducing water pump efficiency.

2. vertical long axis pump impeller and pump shaft assembly gap:

Impeller and shaft assembly vertical long shaft pump is clearance fit, the gap in 0.00mm 0.04 mm, which is decided by the water pump shaft and impeller machining tolerances, clearance or interference on the one hand to increase the difficulty of assembly, also affect the thermal expansion of the rotor components to increase the swaying of the rotor acquired the rotor caused by quality the unbalanced, the gap is too large to increase pump rotor swaying, causing pump rotor balance is not stable, and shaft with the hole location within the impeller, due to the long-term use and repeated disassembly, the gap increases, then you can be with the shaft or impeller for inner hole spray repair method.

3. adjustment of pump shaft key and key gap:

Water pump impeller and pump shaft by key transfer rotation. The key and pump shaft key slot shall be interference fit, the tightening force is 0 mm - 0.03 mm, the key and impeller keyway shall be clearance fit, and the value is 0 mm - 0.03mm.

4. vertical long axis pump rotor small installation:

A) small packs. Also called pre installed or installed small rotor test equipment, is the key to determining the assembly quality, its purpose: to measure and eliminate the rotor tight state rock, in order to avoid internal friction, reduce vibration and improve the seal condition; adjust the axial distance between the impeller and the impeller outlet at all levels to ensure alignment; determine adjust the set size.

(b) determination of the axial expansion clearance of the rotor package, since the rotor package is not the same as the pump shaft material. In addition, the two ends of the pump shaft in the pump body, so hot, the pump shaft and the rotor set expansion is larger than the pump shaft, so the expansion of the rotor gap values are determined according to the length of the rotor and the temperature, generally about 10 impeller rotor about its expansion gap around 1 mm, the expansion gap too large, can not tighten the rotor set, the expansion gap is too small, it may cause the rotor thermal bending under. Cause static and dynamic friction, damage to equipment.

(c) inspection before small installation, check the size of each part on the rotor and eliminate the obvious deviation. Generally, the shaft assembly shall not exceed 0.02 mm, and all the packages on the shaft, such as impeller, balance plate, shaft sleeve and so on, shall be carried out on the special tools facing the verticality of the center of the shaft. False axis and set pieces to keep 0 mm - 0.04 mm gap with the hand rotating set pieces, rotate the dial indicator after a week of beating value should be less than 0.015 mm, with the same method, check the other end verticality, can not leave the shaft, the measuring equipment pieces on the plate, so the measurement method can not come to face with the center line of the vertical axis error, the error is on the lower end of the parallel.