Design and Analysis of Electric bike Hub-Motor using Motor-CAD

Abstract

Inner rotor and outer rotor brushless dc motors are in vogue nowadays as they are currently being used in designing electric bikes. BLDC motors have a wide range of advantages (like higher efficiency smaller size). The E-Magnetic analysis and Lab model analysis are an important part of designing an outer rotor BLDC Hub motor because the motor is attached to the wheels of the bike. It is significantly different from a petrol engine motorbike as in a petrol engine motorbike, the engine and the wheel are separate. So, any heating of the engine would not heat the wheel but for the case of an electric bike, since the hub motor and the bike wheel are not separated from each other, heating of the hub motor would produce a similar type of heating in the wheels. If the temperatures and the total magnetic flux density of the hub motor go beyond normal values, then there would be a chance that the electric motorbike would not start at all. In this work, both the E Magnetic analysis and the Lab model analysis are done on a 36 slot, 24 poles outer rotor BLDC motor which was also designed in Ansys Motor-CAD. All the E Magnetic plots and Lab plots obtained from the analysis are clearly shown in this paper. The different views of the model in terms of axial, radial, and schematic are also shown clearly. This research work provides a clear-cut idea of how correctly analyze a motor E-magnetically which is the first very important step in further analysis of the thermal model in Ansys Motor-CAD.