Abstract: With the advancement of new energy vehicle technology and the continuous increase in motor speeds, the noise, vibration, harshness (NVH) issues of reducer gear pairs under different motor speeds and torque conditions have become increasingly prominent. To address the whining noise encountered by battery electric vehicles under acceleration and coasting conditions, this study conducted testing and analysis based on common speed and torque operating conditions, followed by gear modification. Finally, the modification parameters were validated through real-vehicle noise testing and comparative experiments. The results show that by adjusting the tooth width and helix angle, the contact ratio was increased from 4.140 to 4.449. Through optimization of three key parameters–profile crowning amount, lead crowning amount, and lead slope–the noise in the problematic speed range under acceleration and coasting conditions was reduced by 5~10 dB(A),significantly improving the overall vehicle NVH performance.

Key words: motor; reducer; gear modification; noise; NVH performance; crowning amount

摘要： 随着新能源汽车技术的发展，电机转速的不断提高，减速器齿轮副在电机不同转速及 转矩工况下的噪声、振动与声振粗糙度（NVH）问题越发突出。为此，针对纯电动汽车在加 速、滑行工况遇到的啸叫问题，结合常用转速和转矩工况，进行测试分析，并对齿轮进行修 形；最后通过实车噪音测试及对比试验，确认修形参数。结果表明，通过调整齿宽和螺旋角， 将重合度从 4.140 提升到 4.449；通过对齿形鼓形量、齿向鼓形量、齿向斜率三个重要因素的 调整，对加速、滑行工况在问题转速段的噪音优化 5～10 dB(A)，明显改善整车 NVH 性能。

关键词: 电机；减速器；齿轮修形；噪音；NVH 性能；鼓形量