Conference: 2020 한국자기학회 동계학술대회
Authors: 위성혁, 이수경, 유준열, 황성우, 박수환, 임명섭
DOI:
Recently, turbo chargers have been used to improved efficiency and power of the powertrain. The turbo chargers increase the charging efficiency of the mixed gas by driving the turbine using exhaust energy. However, turbo lag can occur due to small exhaust energy when engine speed is low. To reduce the turbo lag, ultra-high-speed motor is necessary to drive the turbine at low speed of the engine. As a result, research on ultra-high-speed motors for turbochargers has been studied. As the ultra-high-speed motor is driving at much high speed than the other motors, the rotor is affected by high centrifugal force due to its high speed. Therefore, to analyze which part of the rotor is fragile at high speed is important. For this purpose, the stress on each part of the rotor should be analyzed when designing the ultra-high-speed motor. The stress can be calculated by finite element method but it is inefficient because it requires much time to compute the partial differential equations. Thus, it is better to use the analtic method for calculating the stress of the rotor. Since the rotor shape of the ultra-high-speed motor has a simple shape, such as Fig. 1., the stress analysis is carried out using an analytical method.
In this paper, we designed the ultra-high-speed motor that satisfy mechanical stiffness and electromagnetic performance in consideration of design specifications. Analytical methods are used to select the rotor outer diameter range. The design process is as shown Fig. 2. Finally, proceed with verification of the mechanical stiffness and electromagnetic performance. Fig. 3. shows the results of the verification of mechanical stiffness by using FEM. The torque that satisfies the target is shown in the Fig. 4.