Ultrasonic motor

An ultrasonic motor comprising:

• an annular stator including an elastic member and piezo-electric elements secured to said elastic member which generates a travelling wave on [the] a surface of the elastic member by being applied with high frequency voltages;
• and
• a rotor which is in pressure-contact with the elastic member and is driven to be rotated with respect to said stator by virtue of the travelling wave,
• said rotor including a cylindrical main body and a thin flange integrally secured to [the] a periphery of the rotor main body at one end of the main body facing the stator, and a cylindrical vibration portion secured to an end face of the flange and having a diameter different from that of the rotor main body, said vibration portion extending in a direction which is the same as the vibration direction of the travelling wave, said rotor satisfying the following relation, 1.ltoreq.(b/t).ltoreq.3.5 wherein t designates [the] a thickness of the flange in a direction of the rotational axis and b designates [the] a width of the vibration portion in a radial direction.

An ultrasonic motor comprising;

• an annular stator including an elastic member and piezo-electric elements secured to said elastic member which generates a travelling wave on [the] a surface of the elastic member by being applied with high frequency voltages;
• and
• a rotor which is in pressure-contact with the elastic member and is driven to be rotated with respect to said stator by virtue of the travelling wave,
• said rotor including a cylindrical main body and a flange integrally secured to [the] a periphery of the rotor main body at one end of the main body opposing the stator, and a cylindrical vibration portion secured to an end face of the flange and having a diameter different from that of the rotor main body, said vibration portion extending in a direction which is the same as the vibration direction of the travelling wave, said rotor satisfying the following relation:
• 5<(h/t)<15 wherein t designates [the] a thickness of the flange and h designates [the] a height of the vibration portion in a direction of the vibration of the travelling wave.

An ultrasonic motor comprising:

• a stator consisting of an elastic member and an electromechanical energy transducing element which generates a vibration on a surface of said elastic member;
• a rotor which is in pressure-contact with the surface of said elastic member and is rotated about an axis relative to said stator responsive to said vibration;
• and
• said rotor being a cylindrical main body and a flange integrally joined to a periphery of the rotor main body at one end of the main body opposing said stator, and a cylindrical vibration portion secured to an end face of said flange and having a diameter different from that of the rotor main body, said vibration portion extending in the direction of said axis of rotation, said rotor satisfying a relation:
• <
• (h/t)<15 wherein t designates the thickness of the flange measured in the axial direction, and h designates the height of the vibration portion measured in the axial direction.

An ultrasonic motor comprising:

• a stator formed of an elastic member and an electromechanical energy transducing element which generates a vibration on a surface of said elastic member;
• a rotor which is in pressure-contact with the surface of said elastic member and is rotated about an axis relatively to said stator responsive to said vibration;
• and
• said rotor being a cylindrical main body and a flange integrally secured to a periphery of the rotor main body at one end of the main body opposing said stator, and a cylindrical vibration portion secured to an end face of said flange and having a diameter different from that of the rotor main body, said vibration portion extending in a direction of said axis of rotation, said rotor satisfying a relation;
• .ltoreq. (b/t).ltoreq.3.5 wherein t designates a thickness of the flange measured in the direction of the axis of rotation, and b designates a width of the vibration portion measured in a radial direction.

An ultrasonic motor comprising:

• a stator formed of an elastic member and an electromechanical energy transducing element which generates a vibration on a surface of said elastic member;
• and
• a rotor which is in pressure-contact with said elastic member and is rotated relative to said stator responsive to said vibration, said rotor comprising a cylindrical main body, a flange integrally secured to a periphery of the main body at an end face thereof facing the stator and a cylindrical vibration portion secured to an end face of the flange and having a diameter different from that of the rotor main body, said vibration portion extending in a direction of an axis of rotation of said rotor, said rotor satisfying the following relation;
• 5<(h/t)<15 wherein 5 designates a thickness of the flange in an axial direction, and h designates a height of the vibration portion in an axial direction.