Patents by Inventor Masaki Ohfuji
Masaki Ohfuji 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).
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Patent number: 10352327Abstract: A vacuum pump includes: a rotor that is rotated to perform evacuation; a pump disassembly detection circuit that detects a disassembled state in which the vacuum pump is disassembled; and a pump operation prohibition circuit that prohibits rotary drive of the rotor when the pump operation prohibition circuit determines that the pump disassembly detection circuit has detected the disassembled state.Type: GrantFiled: December 19, 2011Date of Patent: July 16, 2019Assignee: SHIMADZU CORPORATIONInventors: Masaki Ohfuji, Toshifumi Hashimoto, Shingo Tanaka
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Patent number: 9353755Abstract: A turbomolecular pump device includes: a turbomolecular pump main body; a power unit that drives the turbomolecular pump main body; and a water cooling unit that is provided between the turbomolecular pump main body and the power unit, wherein components provided in a casing of the power unit are classified into an intensive cooling required component that requires intensive cooling, a moderate cooling required component that requires moderate cooling, and a no cooling required component that requires substantially no cooling, the intensive cooling required component is mounted on a first high-conductivity substrate contacting to the water cooling unit, the moderate cooling required component is mounted on a second high heat-conductive substrate contacting to an inner surface of the casing, and the no cooling required component is mounted on a substrate arranged in a space between the first high heat-conductive substrate and the second high heat-conductive substrate.Type: GrantFiled: March 11, 2010Date of Patent: May 31, 2016Assignee: SHIMADZU CORPORATIONInventors: Yoshihiro Nagano, Masaki Ohfuji, Junichiro Kozaki
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Patent number: 8613604Abstract: The provision of the components requiring cooling on top of the cooling mechanism enables the cooling efficiency to be increased. Furthermore, a case of a control device is attached to the cooling mechanism whereon the components requiring cooling are disposed. The cooling mechanism fulfills the role of the contact surface of the case of the control device with the turbomolecular pump main unit, where the case does not have a case panel on the contact surface with the turbomolecular pump main unit. The cooling mechanism fulfills the role of one surface of the case for the control device, where the cooling mechanism is structured integrally with the control device. Additionally, the turbomolecular pump main unit, the cooling mechanism, and the control device are structured integrally by the turbomolecular pump main unit and the cooling mechanism being in contact.Type: GrantFiled: March 18, 2010Date of Patent: December 24, 2013Assignee: Shimadzu CorporationInventors: Yoshihiro Nagano, Toshiki Yamaguchi, Takuto Onishi, Masaki Ohfuji, Junichiro Kozaki
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Publication number: 20130224042Abstract: A vacuum pump includes: a rotor that is rotated to perform evacuation; a pump disassembly detection circuit that detects a disassembled state in which the vacuum pump is disassembled; and a pump operation prohibition circuit that prohibits rotary drive of the rotor when the pump operation prohibition circuit determines that the pump disassembly detection circuit has detected the disassembled state.Type: ApplicationFiled: December 19, 2011Publication date: August 29, 2013Applicant: SHIMADZU CORPORATIONInventors: Masaki Ohfuji, Toshifumi Hashimoto, Shingo Tanaka
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Publication number: 20120321442Abstract: A turbomolecular pump device includes: a turbomolecular pump main body; a power unit that drives the turbomolecular pump main body; and a water cooling unit that is provided between the turbomolecular pump main body and the power unit, wherein components provided in a casing of the power unit are classified into an intensive cooling required component that requires intensive cooling, a moderate cooling required component that requires moderate cooling, and a no cooling required component that requires substantially no cooling, the intensive cooling required component is mounted on a first high-conductivity substrate contacting to the water cooling unit, the moderate cooling required component is mounted on a second high heat-conductive substrate contacting to an inner surface of the casing, and the no cooling required component is mounted on a substrate arranged in a space between the first high heat-conductive substrate and the second high heat-conductive substrate.Type: ApplicationFiled: March 11, 2010Publication date: December 20, 2012Applicant: SHIMADZU CORPORATIONInventors: Yoshihiro Nagano, Masaki Ohfuji, Junichiro Kozaki
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Patent number: 7965054Abstract: A vacuum pump capable of accurately detecting a rotor temperature based on a change in permeability of a magnetic material. Two targets are fixed to a nut opposed to a gap sensor. The nut is made of pure iron, and a surface of the nut opposed to the gap sensor serves as a target. The target has a Curie temperature greater than a temperature monitoring range, and each of the targets has a Curie temperature falling within the temperature monitoring range. When the targets become opposed to the gap sensor in turn according to rotation of a rotor, three types of signals are output from the gap sensor. The difference-signal generation means generates a difference signal of each the targets, on the basis of a signal of the target. The difference signal is compared with a reference signal V0 for detecting the Curie temperatures to detect a rotor temperature.Type: GrantFiled: July 26, 2007Date of Patent: June 21, 2011Assignee: Shimadzu CorporationInventors: Yoshio Tsunazawa, Akira Arakawa, Junichiro Kozaki, Masaki Ohfuji
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Publication number: 20100247336Abstract: The provision of the components requiring cooling on top of the cooling mechanism enables the cooling efficiency to be increased. Furthermore, a case of a control device is attached to the cooling mechanism whereon the components requiring cooling are disposed. The cooling mechanism fulfills the role of the contact surface of the case of the control device with the turbomolecular pump main unit, where the case does not have a case panel on the contact surface with the turbomolecular pump main unit. The cooling mechanism fulfills the role of one surface of the case for the control device, where the cooling mechanism is structured integrally with the control device. Additionally, the turbomolecular pump main unit, the cooling mechanism, and the control device are structured integrally by the turbomolecular pump main unit and the cooling mechanism being in contact.Type: ApplicationFiled: March 18, 2010Publication date: September 30, 2010Applicant: SHIMADZU CORPORATIONInventors: Yoshihiro Nagano, Toshiki Yamaguchi, Takuto Onishi, Masaki Ohfuji, Junichiro Kozaki
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Patent number: 7679248Abstract: Disclosed is a magnetic bearing system capable of simplifying a demodulation operation and reducing a processing load associated with a magnetic levitation control. A carrier signal having a frequency fc is apply to a sensor through a filter. The sensor operates to modulate the carrier signal, and a difference amplifier operates to calculate a difference between the amplitude-modulated signal FAM (t) and a sensor reference signal Fstd (t). An A/D converter operates to A/D convert a difference signal Fsub (t) output from the difference amplifier to a discretized sensor signal. In the A/D conversion, a sampling frequency fs is set to satisfy the following relation: fc: fc=n·fs or fc=fs/2 (n is a natural number). Thus, the discretized sensor signal includes no carrier wave, and therefore a demodulation operation which has been previously essential can be simplified.Type: GrantFiled: November 7, 2007Date of Patent: March 16, 2010Assignee: Shimadzu CorporationInventors: Junichiro Kozaki, Masaki Ohfuji
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Patent number: 7564670Abstract: A magnetic bearing system for use in a vacuum pump including a motor provided with a rotary blade. The magnetic bearing system including a rotary shaft rotationally holding said rotor, a motor for rotationally driving said rotary shaft, a magnetic levitation section for supporting said rotor relative to a stator through said rotary shaft in a non-contact manner, a rotation detection section for detecting a rotational speed of said rotor, a rotor-temperature detection section for detecting a temperature of said rotor; a carrier-wave generation section for supplying a common carrier wave to each of a plurality of sensors provided in said magnetic levitation section, said rotation detection section and said rotor-temperature detection section, and an A/D conversion section for sampling a sensor signal output from each of said sensors, in synchronization with said carrier wave.Type: GrantFiled: April 30, 2007Date of Patent: July 21, 2009Assignee: Shimadzu CorporationInventors: Junichiro Kozaki, Masaki Ohfuji, Nobuhiko Moriyama
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Publication number: 20090028720Abstract: A vacuum pump capable of accurately detecting a rotor temperature based on a change in permeability of a magnetic material. Two targets are fixed to a nut opposed to a gap sensor. The nut is made of pure iron, and a surface of the nut opposed to the gap sensor serves as a target. The target has a Curie temperature greater than a temperature monitoring range, and each of the targets has a Curie temperature falling within the temperature monitoring range. When the targets become opposed to the gap sensor in turn according to rotation of a rotor, three types of signals are output from the gap sensor. The difference-signal generation means generates a difference signal of each the targets, on the basis of a signal of the target. The difference signal is compared with a reference signal V0 for detecting the Curie temperatures to detect a rotor temperature.Type: ApplicationFiled: July 26, 2007Publication date: January 29, 2009Applicant: SHIMADZU CORPORATIONInventors: Yoshio Tsunazawa, Akira Arakawa, Junichiro Kozaki, Masaki Ohfuji
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Patent number: 7417398Abstract: A vacuum pump includes at least one magnetic body located on a circle about a rotor rotational axis and having a Curie temperature within a rotor temperature monitoring range; an inductance detecting portion facing the circle so as to establish a gap between the circle and the inductance detecting portion, for detecting a change of magnetic permeability of the magnetic body as an inductance change when the magnetic body rotates; and a carrier generation device generating a carrier signal for providing in the inductance detecting portion. An A/D conversion device samples a detection signal of the inductance detecting portion synchronously with a carrier generation by the carrier generation device, and converts the detection signal to a digital signal. A determination device determines whether or not a temperature of the rotor exceeds a predetermined temperature, based on the change of the magnetic permeability of the magnetic body.Type: GrantFiled: November 30, 2006Date of Patent: August 26, 2008Assignee: Shimadzu CorporationInventors: Junichiro Kozaki, Yoshio Tsunazawa, Akira Arakawa, Masaki Ohfuji
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Publication number: 20080088398Abstract: Disclosed is a magnetic bearing system capable of simplifying a demodulation operation and reducing a processing load associated with a magnetic levitation control. A carrier signal having a frequency fc is apply to a sensor through a filter. The sensor operates to modulate the carrier signal, and a difference amplifier operates to calculate a difference between the amplitude-modulated signal FAM (t) and a sensor reference signal Fstd (t). An A/D converter operates to A/D convert a difference signal Fsub (t) output from the difference amplifier to a discretized sensor signal. In the A/D conversion, a sampling frequency fs is set to satisfy the following relation: fc: fc=n·fs or fc=fs/2 (n is a natural number). Thus, the discretized sensor signal includes no carrier wave, and therefore a demodulation operation which has been previously essential can be simplified.Type: ApplicationFiled: November 7, 2007Publication date: April 17, 2008Applicant: SHIMADZU CORPORATIONInventors: Junichiro KOZAKI, Masaki OHFUJI
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Publication number: 20070278884Abstract: Disclosed is a magnetic bearing system for use in a vacuum pump including a rotor provided with a rotary blade. The magnetic bearing system comprises a rotary shaft rotationally holding the rotor, a motor for rotationally driving the rotary shaft, a magnetic levitation section for supporting the rotor relative to a stator through the rotary shaft in a non-contact manner, a rotation detection section for detecting a magnetic pole position of the motor, a rotor-temperature detection section for detecting a temperature of the rotor, a carrier-wave generation section for supplying a common carrier wave to each of a plurality of sensors provided in the magnetic levitation section, the rotation detection section and the rotor-temperature detection section, and an A/D conversion section for sampling a sensor signal output from each of the sensors, in synchronization with the carrier wave.Type: ApplicationFiled: April 30, 2007Publication date: December 6, 2007Applicant: SHIMADZU CORPORATIONInventors: Junichiro Kozaki, Masaki Ohfuji, Nobuhiko Moriyama
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Publication number: 20070145929Abstract: A vacuum pump includes at least one magnetic body located on a circle about a rotor rotational axis and having a Curie temperature within a rotor temperature monitoring range; an inductance detecting portion facing the circle so as to establish a gap between the circle and the inductance detecting portion, for detecting a change of magnetic permeability of the magnetic body as an inductance change when the magnetic body rotates; and a carrier generation device generating a carrier signal for providing in the inductance detecting portion. An A/D conversion device samples a detection signal of the inductance detecting portion synchronously with a carrier generation by the carrier generation device, and converts the detection signal to a digital signal. A determination device determines whether or not a temperature of the rotor exceeds a predetermined temperature, based on the change of the magnetic permeability of the magnetic body.Type: ApplicationFiled: November 30, 2006Publication date: June 28, 2007Applicant: SHIMADZU CORPORATIONInventors: Junichiro Kozaki, Yoshio Tsunazawa, Akira Arakawa, Masaki Ohfuji