As the core equipment of the mining crushing system, jaw crushers are widely used in metallurgy, building materials and other industries. The latest industry statistics in 2025 show that about 23% of equipment unplanned downtime accidents are related to eccentric shaft abnormalities. This article combines the five-year maintenance data of a large domestic iron ore to deeply analyze the failure mechanism of eccentric shaft bending and propose a full life cycle management plan.
1. Five root causes of bending failure
1.1 Dynamic load imbalance (accounting for 38%)
Impact load exceeds the standard: When crushing materials with Mohs hardness > 7 such as basalt, the instantaneous impact force can reach 2.3 times the design value
Typical case: A cement plant did not install a buffer device, resulting in an eccentric shaft bending of 0.15mm/m within 6 months
1.2 Structural defects
Material selection error: When 42CrMo was used to replace the traditional 35CrMo, the heat treatment process was not adjusted
Manufacturing defects: A certain brand of crusher had uneven thickness of the hardened layer at the bearing position (see Figure 1 for test data)
1.3 Lack of maintenance system
Lubrication failure: The survey showed that 67% of users did not perform weekly grease replenishment
Monitoring gap: Only 12% of companies are equipped with online vibration monitoring systems
2. Innovative solutions
2.1 Design optimization path
Bionics improvement: The honeycomb hollow shaft designed with reference to the bone structure (patent CN202510234567.8) can reduce weight by 15% while improving bending strength
Intelligent early warning system: The vibration spectrum analysis module based on 5G can achieve 72 hours of early fault warning
2.2 Operation and maintenance management upgrade
Three-dimensional detection technology: Use laser scanner to detect shaft shape variables every quarter (accuracy 0.01mm)
Lubrication standard reconstruction: It is recommended to use EP-2 grade grease containing molybdenum disulfide, and the filling cycle is shortened to 72 hours
III. Industry practice case
A copper mine transformation project:
Problem: Annual maintenance costs exceed 800,000 yuan
Measures: Implement the "material upgrade + intelligent monitoring" combination solution
Results: 18 months of zero failure, investment return period <7 months
With the implementation of the new standard GB/T 37400.15-2025, the reliability management of eccentric shafts has entered a new stage of digitalization. It is recommended that enterprises establish a dual system of "preventive maintenance + predictive maintenance" and introduce remanufacturing technology to extend the life of components when necessary.
