关键词: 高速永磁电机, 碳纤维护套, 疲劳试验, 应力仿真, 疲劳寿命预测

Abstract: To investigate the fatigue performance of carbon fiber retaining sleeves for high-speed permanent magnet motors under ambient temperatures of 20 ℃ and 90 ℃ , NOL rings with identical material and process parameters as the sleeves were fabricated. Fatigue tests were conducted at different stress levels corresponding to 30%, 40%, 50%, 60%, 70%, and 80% of the static tensile strength. At the same temperature, results showed that fatigue life gradually decreased with increasing stress levels, while NOL rings at 90 ℃ exhibited lower fatigue life compared to those at 20 ℃ . Higher stress levels led to larger coefficient of variation in fatigue life and greater data dispersion. A finite element simulation model
of the rotor was established to analyze stress distribution and deformation. Under maximum rotational speed, the sleeve′ s peak stress reached 1 052. 5 MPa ( significantly below its static tensile strength of 2 270 MPa) , with maximum deformation of 0. 38 mm, indicating safe operational limits. Using Miner′ s linear cumulative damage theory, a fatigue life prediction model was developed. The model was used to predict fatigue life under a load spectrum complied from three operating conditions and convert in into maximum driving mileage. Comparison with the actual maximum driving mileage showed a prediction error of 7. 402 4%.

Key words: high-speed permanent magnet motor, carbon fiber retaining sleeve, fatigue test, stress simulation, fatigue life predition