Patents by Inventor Hirokazu Yashiro
Hirokazu Yashiro has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 6815855Abstract: A compact turbo-molecular pump having a high depressurizing capability. A motor for rotating a rotor vane includes an air bearing. The air bearing has a rotary cylinder and a fixed surface surrounding the rotary cylinder. The material of the rotary cylinder has a coefficient of thermal expansion that is smaller than that of the material of the fixed surface. Thus, change in the dimensions of the rotary cylinder is smaller than that of the fixed surface even if the temperature of the air bearing rises during operation of the pump. Thus, the rotary cylinder avoids contact with the fixed surface.Type: GrantFiled: August 6, 2003Date of Patent: November 9, 2004Assignee: Ibiden Co., Ltd.Inventors: Hirokazu Yashiro, Youichi Kuwayama
-
Patent number: 6784580Abstract: A compact turbo-molecular pump having a high depressurizing capability. A motor driving the pump includes a rotary shaft, the distal and basal ends of which are supported by magnetic bearings. Each magnetic bearing has a rotated magnet, which is rotated integrally with the rotary shaft, and a fixed magnet, which is opposed to the rotated magnet. The rotated and fixed magnets repel each other. The diameter of the magnetic bearing at the distal end of the rotary shaft is greater than that of the magnetic bearing at the basal end. This decreases movement of the rotary shaft toward its distal end when the pump operates.Type: GrantFiled: November 5, 2002Date of Patent: August 31, 2004Assignee: Ibiden Co., Ltd.Inventors: Hirokazu Yashiro, Youichi Kuwayama
-
Publication number: 20040027019Abstract: A compact turbo-molecular pump having a high depressurizing capability. A motor for rotating a rotor vane includes an air bearing. The air bearing has a rotary cylinder and a fixed surface surrounding the rotary cylinder. The material of the rotary cylinder has a coefficient of thermal expansion that is smaller than that of the material of the fixed surface. Thus, change in the dimensions of the rotary cylinder is smaller than that of the fixed surface even if the temperature of the air bearing rises during operation of the pump. Thus, the rotary cylinder avoids contact with the fixed surface.Type: ApplicationFiled: August 6, 2003Publication date: February 12, 2004Applicant: Ibiden Co., Ltd.Inventors: Hirokazu Yashiro, Youichi Kuwayama
-
Patent number: 6664683Abstract: A compact turbo-molecular pump having a high depressurizing capability. A motor for rotating a rotor vane includes an air bearing. The air bearing has a rotary cylinder and a fixed surface surrounding the rotary cylinder. The material of the rotary cylinder has a coefficient of thermal expansion that is smaller than that of the material of the fixed surface. Thus, change in the dimensions of the rotary cylinder is smaller than that of the fixed surface even if the temperature of the air bearing rises during operation of the pump. Thus, the rotary cylinder avoids contact with the fixed surface.Type: GrantFiled: January 28, 2000Date of Patent: December 16, 2003Assignee: Ibiden Co., LTDInventors: Hirokazu Yashiro, Youichi Kuwayama
-
Publication number: 20030102748Abstract: A compact turbo-molecular pump having a high depressurizing capability. A motor driving the pump includes a rotary shaft, the distal and basal ends of which are supported by magnetic bearings. Each magnetic bearing has a rotated magnet, which is rotated integrally with the rotary shaft, and a fixed magnet, which is opposed to the rotated magnet. The rotated and fixed magnets repel each other. The diameter of the magnetic bearing at the distal end of the rotary shaft is greater than that of the magnetic bearing at the basal end. This decreases movement of the rotary shaft toward its distal end when the pump operates.Type: ApplicationFiled: November 5, 2002Publication date: June 5, 2003Applicant: Ibiden Co., Ltd.Inventors: Hirokazu Yashiro, Youichi Kuwayama
-
Patent number: 6498410Abstract: A compact turbo-molecular pump having a high depressurizing capability. A motor driving the pump includes a rotary shaft, the distal and basal ends of which are supported by magnetic bearings. Each magnetic bearing has a rotated magnet, which is rotated integrally with the rotary shaft, and a fixed magnet, which is opposed to the rotated magnet. The rotated and fixed magnets repel each other. The diameter of the magnetic bearing at the distal end of the rotary shaft is greater than that of the magnetic bearing at the basal end. This decreases movement of the rotary shaft toward its distal end when the pump operates.Type: GrantFiled: March 28, 2000Date of Patent: December 24, 2002Assignee: Ibiden Co., Ltd.Inventors: Hirokazu Yashiro, Youichi Kuwayama
-
Patent number: 6091216Abstract: When a brushless motor is rotated at low speeds (the answer of a step S12 is YES), the brushless motor is driven by exciting a first phase coil, a second phase coil and a third phase coil by a sine wave PWM system having a phase difference of 120.degree. from each other to perform a torque control. Since the crest value of the sine wave is controlled in response to torque greatly fluctuated by a load, an out-of-phase phenomenon which is apt to occur at low rotational speeds can be previously prevented. When the brushless motor is rotated at high speeds (the answer of the step S12 is NO), the brushless motor is driven by a square wave PWM system based on a three-phase 120.degree. conduction type. Since the out-of-phase phenomenon is apt to occur as a frequency is increased when the brushless motor is driven by the sine wave PWM system, the control system is switched to a square wave PWM system to prevent the out-of-phase phenomenon.Type: GrantFiled: June 19, 1998Date of Patent: July 18, 2000Assignee: Ibiden Co., Ltd.Inventors: Hisashi Takahashi, Hirokazu Yashiro, Takashi Kenjo, Koichiro Shoji
-
Patent number: 5168186Abstract: A spindle motor for high speed hand tools includes a rotor and a sleeve that is journaled about the rotor. A pressure generating mechanism creates sufficient air pressure in a clearance between the rotor and the sleeve to form a pressurized air film in the clearance when the spindle motor is in normal operation. A plurality of armature coils and a plurality of magnetic sensors for detecting magnetism of magnetic poles in the rotor are provided on the outer surface of the sleeve. The rotor has a field magnet with multiple magnetic poles. The sleeve is formed of a ceramic material whose dielectric constant is 10 or lower. The pressurized air film created by the pressure generating mechanism is sufficient to radially support the rotor so that the rotor does not significantly contact the sleeve during normal operation of the spindle motor.Type: GrantFiled: September 10, 1991Date of Patent: December 1, 1992Assignee: Ibiden Co., Ltd.Inventor: Hirokazu Yashiro