Patent ID: 7375446

Claim:
An actuator for use with a fluid channel structure, the actuator comprising: a) a stator assembly including stator yokes, a coil disposed between the stator yokes, and a front plate attached to the stator yokes; and b) a rotor assembly disposed inside the stator assembly, and including a housing including a ring plate portion, a circular hollow-cylinder portion continuous with the ring plate portion, and a flange portion disposed at an outer circumference of the circular hollow-cylinder portion, the housing further including first and second elastic sealing units disposed at the outer circumference of the circular hollow-cylinder portion so as to be located apart from each other, wherein the first elastic sealing unit makes hermetic contact with a wall of a fluid channel of the fluid channel structure, an output shaft inserted through an opening of the ring plate portion of the housing, a sleeve disposed around the output shaft, a magnet fixedly attached to an outer circumference of the sleeve, and a rotor case having a cup-like configuration, wherein the second elastic sealing unit located inside the rotor case makes hermetic contact with an open end portion of the rotor case so as to fit tightly the rotor case with the circular hollow-cylinder portion of the housing.