Abstract: A canned motor pump has a rotor 130 rotatably provided in the first tube cup 270. The rotor 130 further includes the second tube cup 190 and the cap 170, and the raindropshaped protrusion is provided on each bottom surface of the second tube cup and exterior surface of the cap. The motor end cover 110 having a louvered lip, further, is provided between the pump 30 and the motor 100.

Abstract: Apparatus and method for manufacturing an impeller consisting of a body with many vanes and a shroud joined with the body. The apparatus comprises a die for chucking the body, a horn for supporting the shroud to be in contact with the vanes while the body is chucked by the die, a torque motor for applying vibration to the horn, and a pneumatic cylinder for giving pressure to the torque motor so that the shroud and the body are pushed in a contacting direction with each other. The torque motor is driven by half-wave rectified alternating current, and generates twisting vibration of the frequency between 10 Hz and 1 kHz. The shroud and the body are firmly joined by the twisting vibration. Thus little burr is generated. Further, the present invention can be adopted for manufacturing the impeller elements of diverse materials.