Nidec Machine Tool Corporation, a subsidiary of Nidec Corporation, has unveiled the pioneering achievement of creating a high-precision polishing technique. This innovative method, designed for mass production, is capable of machining internal gears utilized in automotive drive units, transmissions, and robotic joints, marking a significant advancement in the industry.
Established in Kyoto, Japan in 1973 under the leadership of Chairman Shigenobu Nagamori, Nidec made history in 1979 by pioneering the commercialization of a direct drive spindle motor for HDDs, leveraging brushless DC motor technology. With annual sales surpassing $13B, the company’s extensive portfolio spans motors, drives, generators, and associated products, catering to a wide array of industries including computing, telecommunications, household appliances, automotive, industrial automation, and robotics.
While existing methods excel in accurately machining external gears for mass production, the internal gear machining domain has lacked similar precision until now. Through dedicated research, the company has achieved breakthroughs, surpassing the accuracy and efficiency of conventional grinding, honing, or skiving methods for internal gears. The significance lies in the fact that even minor distortions in gears, as integral components of planetary gear mechanisms, can profoundly impact durability, transmission efficiency, and mitigate noise and vibration.
With the burgeoning electrification and automation of products, the demand for high-precision gears is escalating. Recognizing this imperative, the company swiftly developed and introduced this innovative machining technique to enhance gears’ durability, transmission efficiency, and NVH (noise, vibration, and harshness) performance, thereby contributing to industry advancement.
The most recent research and development endeavor have pinpointed and formulated machining parameters tailored to Nidec Machine Tool’s cutting-edge processing machinery and techniques. This initiative constitutes a collaborative investigation alongside Germany’s RWTH Aachen University. For additional insights into this project, kindly refer to the accompanying document.
Utilizing its proprietary technology, the Company employed the ZI20A grinding machine, introduced in 2009, for the mass production of internal gears. This machinery boasts the capability to achieve exceptionally precise internal gear processing, meeting the productivity demands of large-scale manufacturing. In selecting grinding stones, deemed consumables, the Company conducted a preliminary evaluation considering factors such as availability, cost-effectiveness, and suitability for autonomous operation.
By aiming for surface roughness indices of Ra0.1μm and Rz1.0μm or below (standard measures for polished machining), the Company identified optimal machining parameters to uphold post-polish gear accuracy within ISO levels 3 – 5 while mitigating the risk of grinding burn. Nidec Machine Tool, equipped with cutting-edge gear-machining technology, offers a range of machines, tools, and machining solutions aimed at steadfastly addressing societal challenges and making meaningful contributions towards their resolution.
