Development of a High-Performance Spindle for Multitasking Machine Tools
Taku Yamazaki1, Toshiyuki Muraki2, Atsushi Matsubara2,
Mitsuho Aoki3, Kenji Iwawaki4, and Kazuyuki Kawashima4
1Development and Design Department, Yamazaki Mazak Corporation, Oguchi-cho, Aichi 480-0197, Japan
2Department of Micro Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-0024, Japan
3Precision Bearing Technology Department, NSK Corporation, 1-5-50, Kugenuma Shinmei, Fujisawa-shi, Kanagawa 251-8501, Japan
4Servo Motor Manufacturing Department, Mitsubishi Electric Corporation, 1-14, Yada-minami 5-chome, Higashi-ku, Nagoya-shi, Aichi 461-8670, Japan
In recent years, high-performance spindles are required for multi-tasking machine tools to enhance the productivity. Such spindles enable efficient rough cutting and fine finishing of a workpiece on one machine. In order to meet this requirement, a spindle unit must be highly stiff and operate at high rotational. Spindle specifications require a rotational number of 50,000min-1 and dN value of 3,000,000, a smaller motor was downsized and an electric loss restrained by reducing the thickness of laminate sheets composing the rotor core. A direct-injection type of ultra trace quantity lubrication and a preload switching system were used for ball bearings for high rotational speed and high stiffness. We discuss how these technical requirements were met and the results of basic experiments.
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