目的 为确定步进电机驱动器和EPE衬垫的配合间隙与振动的关系。方法 选取步进电机驱动器为研究对象，以密度为20，28，32 kg/m³的EPE衬垫为隔振包装，研究对象与衬垫在垂直方向的配合间隙为−4，−2，0，2，4 mm。定制木质夹具的密度为32 kg/m³，配合间隙为−4 mm的EPE衬垫模型，参照ASTM-D4169随机振动试验部分的PSD功率谱密度曲线，进行随机振动试验分析。依据试验结果，修正该包装件的仿真模型、接触方式、网格划分等，仿真结果与试验结果的RPSD曲线吻合程度良好。依据该包装件的仿真设置，对密度为20，28 kg/m³的系列配合包装件进行仿真分析。结果 同一密度EPE衬垫，间隙配合比过盈配合振动强度低，0 mm配合的RMS值最小，振动强度最低。同一配合间隙，过盈配合时，EPE衬垫密度越低，RMS值越小，振动强度越低;间隙配合时，EPE衬垫密度越高，RMS值越低，振动强度越低。结论 采用EPE衬垫包装步进电机驱动器时，在同密度衬垫和同量级的外界激励下，0 mm配合隔振性能最佳，间隙配合隔振性能优于过盈配合。

The work aims to determine the relationship between vibration and fit clearance of stepper motor driver and EPE cushion foam. The stepper motor drivers were selected as the research product and EPE cushion foam with densities of 20, 28 and 32 kg/m3 were used as vibration isolation packaging. The fit clearance between the product and the EPE cushion foam in the vertical direction was −4, −2, 0, 2 and 4 mm. Customized wooden fixture and EPE cushion foam model with the density of 32 kg/m3 and the fit clearance of −4 mm were used for random vibration test analysis according to the PSD power spectral density curve of American ASTM-D4169. According to the test results, the simulation model, contact, mesh generation, etc. of the corresponding type of package were modified until the simulation results were in good agreement with the RPSD curve of the test results. According to the simulation setting of the package, the series of fit packages with densities of 20 and 28 kg/m3 were simulated and analyzed. For the EPE cushion foam with the same density, the vibration intensity of clearance fit was lower than that of interference fit. The RMS value and vibration intensity were the lowest at 0 mm fit. For the same fit, the lower the EPE cushion foam density was, the smaller the RMS value was and the lower the vibration intensity was at interference fit. The higher the EPE cushion foam density was, the smaller the RMS value was and the lower the vibration intensity was at clearance fit. When EPE cushion foam is used to pack the stepper motor driver, the vibration isolation performance of 0 mm fit is the best and the vibration isolation performance of clearance fit is better than that of interference fit under the same density of EPE cushion foam and level of external excitation.