Sueyoshi Mizuno

Development of a totally enclosed fan cooled traction motor

The intake of dust and dirt contained outside the air into the motor while driving causes the maintenance of dismantling and clean-up operation once every three years. Moreover, excessive acoustic noise during high-speed operation is produced by the cooling fan on the rotor. Totally enclosed airtight motor was developed not only to deal with the dust-intake problem but also to reduce acoustic noise. This motor eliminates the requirement of periodical dismantling and clean-up operation. Excessive noise of internal cooling fan was decreased by newly developed uneven pitch blade fan. Further, traction motor without external fan was developed by thermofluid simulation. Acoustic noise and temperature rise of these motor were measured and compared.

Bridge and rotor inductances of closed slots induction motor

In this paper, the bridge inductance of closed slot was investigated by a search coil, FEM analysis and conventional equations. The bridge flux density and the bridge linkage flux were measured with removed a closed-slot rotor of 4P-0.75 kW motor. The inductance was also calculated using magnetic energy and magnetic co-energy obtained by FEM.