PURPOSE: To obtain a tank which does not occur deformation by welding ribs for heat sink placed at the outside of vertical slits which are made by cutting a sheet metal plate in vertical way at an intervals wherein spot welding is made for reinforcement bars placed at the inside of the plate and running in horizontal way and the position of spot weld is the middle point of each vertical slit.
CONSTITUTION: Plural slits are provided for a sheet metal plate in vertical direction at predetermined interval and ribs 5 for heat sink are welded by coating each slit with the plate and by protruding the ribs 5 at the outside of the slit. Then, the plate is bent in wavy shape by placing the ribs 5 outward to serve as a tank for oil-filled electrical machine. At that time, plural reinforcement bars 6 provided in the tank are not placed at the upper end 5a of normally installed ribs 5 but provided at the inside of the tank so that the bars may meet at right angles with the slits and the bars are adhered to the plate by spot weld 10. In this way, the strength becomes strong and oil leakage, etc. will be eliminated. Furthermore, easy workability will remarkably be facilitated.
NAKAMURA KOUICHI
HATSUTORI MASASHI
KONDOU TAKESHI
