Bending deformation of motor shaft is one of the common mechanical failures, which may lead to increased equipment vibration, bearing wear, and even damage to the entire machine. To accurately determine whether the motor shaft is bent, multiple methods such as visual inspection, precision measurement, and operational status analysis need to be combined. The following is a systematic detection process and judgment criteria to help you quickly identify problems and take corresponding measures.
1. Appearance inspection and preliminary judgment
·Visual inspection: Observe whether there are obvious scratches, wear or local deformation on the surface of the motor shaft, especially in areas with high load or frequent start stop.
·Manual rotation test: After power off, manually rotate the motor shaft to feel for any jamming, vibration, or imbalance. If the rotation is not smooth or accompanied by abnormal noise, it may indicate that the shaft is bent or the bearing is damaged.
2. Tool measurement and testing
·Dial gauge measurement (commonly used): Install a dial gauge at the bearing positions at both ends and in the middle of the shaft, rotate the shaft once, and observe the radial runout value. The normal motor shaft runout should be ≤ 0.03-0.05mm (depending on the model), and exceeding the tolerance indicates bending.
·Straightedge assisted inspection: Use a ruler to tightly adhere to the surface of the shaft. If the gap changes significantly (larger on one side and smaller on the other) when rotating the shaft, it can be roughly judged as bent.
3. Professional testing methods
·Vibration analysis: By monitoring the vibration spectrum of the motor during operation through vibration sensors, abnormal high-frequency vibrations may be caused by shaft bending or dynamic balance failure.
·Temperature monitoring: Local overheating of bearings or shaft necks may be a signal of increased friction caused by shaft bending.
4. Repair and correction standards
·Slight bending (≤ 0.2mm): can be repaired by polishing or cold correction with a press.
·Severe bending or cracking: If the bending exceeds 0.2mm or there are cracks (crack depth>15% of shaft diameter), a new shaft needs to be replaced or repaired by welding and machining.
5. Precautions
·Environmental factors: Wet or corrosive environments may accelerate shaft deformation, and regular inspection of rust prevention measures is necessary.
·Dynamic verification: After repair, it is necessary to retest the performance of no-load and load operation to ensure no residual vibration or noise.
The comprehensive use of appearance inspection, tool measurement, and professional analysis can accurately determine the degree of motor shaft bending. For critical equipment, it is recommended to conduct standardized testing in accordance with national standards such as GB/T 21205-2022. If unable to handle it on your own, you should contact a professional maintenance unit to avoid secondary damage.
Hengda Electric has always been dedicated to the research and development, production, and service of various types of motors. With advanced technology and equipment, lean manufacturing processes, reliable product quality, and satisfactory after-sales service, the company provides customers with the most suitable motor professional solutions and creates greater social value.
