Maintenance and Bending Measurement of the Rotor Pump Shaft

The rotor pump features a precise structure with minimal clearance between moving and stationary parts. The rotor operates at high speeds, and the shaft bears heavy loads, imposing stringent requirements on the quality and condition of the pump shaft. In daily maintenance and fault repair, the condition of the pump shaft directly affects the stability and efficiency of equipment operation.

(Bonve Pumps Cam Rotor Pumps)

I. Maintenance of the Pump Shaft

If any of the following conditions occur on the pump shaft, replacement with a new shaft should be considered:

- Cracks on the shaft surface;

- Deep grooves on the shaft surface caused by erosion from high-speed water flow, especially near keyways;

- Severe shaft bending that cannot be restored to straightness after multiple corrections.

Generally, the bending of the shaft should not exceed 0.05mm; otherwise, straightening is required. If only local scoring or minor wear is present, repair methods such as thermal spraying or brush plating can be used to restore its dimensions and surface integrity.

II. Measurement of Shaft Bending

Shaft bending measurement should be conducted at room temperature. For most pump shafts, the shaft necks at both ends can be supported on ball stands or V-blocks placed on a flat plate or level concrete floor for measurement. Heavy shafts, such as turbine rotor shafts, are typically measured on their own bearings. Before measurement, axial float must be controlled within 0.1mm to ensure data accuracy.

Measurement Steps:

1. Divide the shaft axially into several measurement segments, selecting smooth shaft sections free from wear and burrs as measurement points.

2. Mark equal divisions on the shaft end face, typically into eight equal parts. For shafts with couplings, division can be based on coupling bolt holes; for those without, start from the keyway as the reference point for equal division, and make permanent marks.

3. Install a dial indicator, ensuring the measuring rod is perpendicular to the axis and passes through the shaft center. After adjusting the indicator needle position, slowly rotate the shaft one full turn to check if the needle returns to its starting point.

4. Slowly rotate the shaft in the same direction, sequentially record the readings at each measurement point. Each cross-section should be measured twice to ensure consistency, with a reading error of less than 0.005mm.

5. Calculate the bending value for each cross-section based on the records. Take half of the difference between two opposite points on the same cross-section and plot a phase diagram.

6. Plot the bending values of each cross-section in a Cartesian coordinate system, with the vertical axis representing the bending value and the horizontal axis representing the shaft length and the positions of measurement cross-sections. Connect the points to form a bending curve. Use the phase diagram to identify the approximate location of maximum bending, then take additional measurements near this point. Connect the measured points to form a smooth shaft bending curve, facilitating accurate judgment of the bending condition and straightening direction.

III. Maintenance Significance

Regular maintenance and bending measurement of the rotor pump shaft not only enable early detection of potential faults but also prevent issues such as increased vibration and accelerated wear caused by shaft bending. This ensures long-term stable operation and extends the service life of the equipment.

Bonve pump always adheres to the philosophy of "Wholeheartedly Making Good Rotor Pumps," committed to providing global customers with customized conveying and mixing solutions. If you have technical inquiries, selection needs, case references, or other cooperation intentions related to Bonve rotor pumps, please feel free to contact us.  

Service Hotline: 0574-87588986 13586591794  

Official Website: www.bvpumps.com  

Business Email: market@bonvepumps.com  

We look forward to working with you to drive efficiency and innovation in industrial fluid transmission with precision technology.