Electric rotating machine

An electric rotating machine comprising:

• a generally tubular yoke having a tubular portion;
• permanent magnets attached to an inner circumference of said tubular portion;
• a pair of lid portions laid on both axial ends of said tubular portion of said yoke;
• through bolts press-fitting said pair of lid portions from said both axial ends to tighten and fix the pair of lid portions to said yoke;
• and
• concave portions formed radially inwardly on said tubular portion and extending axially, wherein an axial center of said through bolts is set on said concave portion inside of a hypothetical extension outer diameter of said tubular portion at said concave portion, and wherein concave end portion of said tubular portion and each of said lid portions are tightened and fixed to directly contact each other.

An electric rotatig machine comprising:

• a yoke shaped generally in a tubular form and having a plurality of concave portions which extend axially and radially inwardly;
• a pair of lids shaped generally in a disk form to cover axial ends of said yoke, at least one of said lids having a plurality of holes at positions where said concave portions face;
• and
• a plurality of through bolts passing through said holes and received on said concave portions, said through bolts tightening said lids axially toward said yoke, an axial center of said bolts being positioned inside an outer diameter of said tubular yoke.