Evaluation of Electric Vehicle (EV) Motor Shafts Produced by Radial Forging

User Benefits

- By using the combined axial force and torsion tester, the axial and torsional loads can be applied simultaneously to the test specimen. - Static torsion tests can be performed on hollow shafts. - Torsional fatigue tests can be performed on hollow shafts.

Introduction

In recent years, the trend toward decarbonization has accelerated to reduce greenhouse gas emissions. The shift to electric vehicles (EVs) in the automotive industry plays a major role in realizing a low-carbon society. In order to promote the use of EVs, there is a need to improve the range of the vehicle, so a development theme is to reduce the weight of the vehicle body. In particular, reduction of shaft weight is an important development theme because it is expected to improve not only the driving range but also the responsiveness of the motor by reducing the inertia force. Radial forging is a new forging technology for hollow shafts. While applying force from the radial direction of a hollow shaft or shaft with a hammer (mold), the inner and outer diameters can be formed simultaneously by inserting a core metal and transferring the inner diameter shape. Hollow shafts manufactured by the radial forging method are attracting attention as a manufacturing method for next-generation shafts because they can achieve both strength and weight reduction. Since hollow shafts are used for motor shafts and cranks, they are often subjected to torsional loads. In addition to simple tension and compression, evaluation using torsional fatigue tests are also important. In the previous report, in order to evaluate the change in mechanical properties during radial forging, specimens were cut from actual products and a multi-faceted evaluation was conducted. As a result, it became clear that the product exhibits excellent characteristics in the radial forging processed area. In this study, torsional fatigue tests were conducted on three types of real products (hollow shaft shapes), radial forging, forging, and blank, and their fatigue characteristics were evaluated.

October 31, 2023 GMT