The influence of the perpendicularity between the motor casing and the end cover flange on the motor air gap

Thread Content

The motor air gap size is an important technical parameter in electromagnetic design and motor operation, and its value directly affects the performance of the motor. The air gap is a dimension that is determined indirectly after the motor has been assembled; its size is influenced by the assembly relationship of the components, as well as the dimensional tolerances of various parts and related areas on those parts. In some conventional calculations of the air gap dimension chain, many engineers overlook the dimensional tolerances of certain components that affect the air gap, such as the perpendicularity between the housing and the end cover flanges. This paper will quantitatively analyze the impact of the perpendicularity between the computer chassis and end cap shoulders on the air gap through a practical case study. Analysis approach to the impact of the perpendicularity between the casing and the end cover flange on the air gap: 1. The radial deviation caused at the bearing center by the perpendicularity between the computer casing and the end cover flange ； 2. Calculate the degree of influence of this radial deviation on the air gap, that is, calculate the contribution of this radial deviation. I. The radial deviation caused at the bearing center due to the perpendicularity of the casing and end cover shoulders; establishment of the dimension chain, input of data for the constituent rings, calculation results. II. The impact of radial deviation on the air gap: calculation of the air gap dimension chain and input of tolerances for the constituent rings, calculation results for the air gap. It can be seen from the calculation results for the air gap that the contributions of the tolerances of each constituent ring in this dimension chain to the final value are relatively similar, with the largest contribution being only 14.8%. The contribution of the perpendicularity between the casing and the end cover flange to the air gap tolerance is approximately 7.5%, indicating that the perpendicularity between them has a significant impact on the air gap tolerance. III. Conclusions 1. The radial deviation caused at the bearing center by the perpendicularity between the casing and the end cover flange is 0.0204 ； 2. As can be seen from the calculation results of the air gap, the perpendicularity between the casing and the end cover flange contributes approximately 7.5% to the tolerance of the air gap. Analysis shows that the perpendicularity between the casing and the end cover has a significant impact on the air gap tolerance, and it cannot be ignored in calculations.