A rotary motor includes bearing frames fixedly secured with a main round frame. The stator unit is secured directly to the round frame. The bearing frames are shallow cup-shaped metal members having an outer cylindrical flange extending as a continuous member about the circumference of a flat end wall structure. The flange is specially constructed to have a maximum diameter slightly greater than the internal diameter of the round frame, and is pressed into the round frame with the frame located on a precise radial plane through the round frame. A rotary bearing is secured within the end frame for rotatably supporting a rotor unit. The bearing frame is preferably a stamped steel member with the flange having a plurality of small radial projections. The bearing frame is pressed into the round frame using a suitable hydraulic press. The end edge of the round frame is formed as a reference for locating of the bearing frame in the round frame. The pressed frame is welded to the main frame at the projections by resistance welding.