Patents by Inventor Naohiko Takahashi
Naohiko Takahashi 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: 11255377Abstract: A tilting-pad-type journal bearing includes a rotary shaft, a plurality of tilting pads, a housing, a fixing structure, an oil inlet, and side plates. The plurality of tilting pads support the rotary shaft in a radial direction. The housing accommodates the plurality of tilting pads inside. The fixing structure fixes a circumferential relative position with respect to the housing while allowing the tilting pads to swing. The oil inlet supplies lubricating oil between the tilting pads and the rotary shaft. The side plates are provided on both sides of the housing in a rotational-axis direction.Type: GrantFiled: October 24, 2017Date of Patent: February 22, 2022Assignee: Hitachi Industrial Products, Ltd.Inventors: Isao Hagiya, Naohiko Takahashi, Jun Ichimura
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Patent number: 11204062Abstract: A tilting pad journal bearing is arranged such that a circumferential relative position of an opening portion of an oil feeding hole to supply lubricant oil to a sliding portion of a bearing pad with respect to the bearing pad differs depending on the position of each bearing pad. For a bearing pad under a rotary shaft which supports the load of the rotary shaft, the circumferential position of an opening portion of an oil feeding hole with respect to the bearing pad is set toward an upstream side of a space between pads in a rotating direction of the rotary shaft. For a bearing pad above the rotary shaft, the circumferential position of an opening portion of an oil feeding hole with respect to the bearing pad is set toward a downstream side of a space between pads in the rotating direction of the rotary shaft.Type: GrantFiled: August 22, 2018Date of Patent: December 21, 2021Assignee: HITACHI INDUSTRIAL PRODUCTS, LTD.Inventors: Makoto Hemmi, Naohiko Takahashi, Jun Ichimura, Motoki Sato
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Publication number: 20210285486Abstract: The purpose of the present invention is to provide a tilting-pad-type journal bearing capable of improving pad cooling performance of lubricating oil and reducing pad temperature. In the tilting-pad-type journal bearing, a tilting pad has a concave part formed to be a down step part from a sliding surface toward the rotational downstream side, and a down step part from the sliding surface from the center of the tilting pad in the rotational-axis direction toward a rotational-axis direction side end, at both side ends of the sliding surface in the rotational-axis direction facing a rotary shaft. Further, in the concave part, the side end side of the tilting pad in the rotational-axis direction is opened toward the inside of a housing.Type: ApplicationFiled: October 24, 2017Publication date: September 16, 2021Inventors: Isao HAGIYA, Naohiko TAKAHASHI, Jun ICHIMURA
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Publication number: 20200355219Abstract: A tilting pad journal bearing is arranged such that a circumferential relative position of an opening portion of an oil feeding hole to supply lubricant oil to a sliding portion of a bearing pad with respect to the bearing pad differs depending on the position of each bearing pad. For a bearing pad under a rotary shaft which supports the load of the rotary shaft, the circumferential position of an opening portion of an oil feeding hole with respect to the bearing pad is set toward an upstream side of a space between pads in a rotating direction of the rotary shaft. For a bearing pad above the rotary shaft, the circumferential position of an opening portion of an oil feeding hole with respect to the bearing pad is set toward a downstream side of a space between pads in the rotating direction of the rotary shaft.Type: ApplicationFiled: August 22, 2018Publication date: November 12, 2020Inventors: Makoto HEMMI, Naohiko TAKAHASHI, Jun ICHIMURA, Motoki SATO
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Publication number: 20200355218Abstract: A tilting pad bearing device of the present invention is as follows: in a tilting pad bearing device including plural tilting pads (2), each of which is swingably disposed on the inside of a bearing housing (4) via a pivot and supports a rotary shaft, a cooling flow path which is a circumferentially communicating path is disposed in a tiling pad and an arrangement is made so that an axial directional position of the cooling flow path inlet is not coincident with an axial directional position of an oil feeding hole (7) for feeding oil to a space between tiling pads. As the cooling flow path, for example, a cooling groove (12) which is a circumferentially communicating groove is disposed in a side face of a tilting pad 2 in an axial direction.Type: ApplicationFiled: August 22, 2018Publication date: November 12, 2020Inventors: Motoki SATO, Makoto HEMMI, Naohiko TAKAHASHI
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Patent number: 9004857Abstract: In a centrifugal compressor, for the purpose of preventing the positions of a diaphragm and a head flange in a radial direction from moving with respect to a casing, preventing the unstable vibration of the rotor and enabling an efficient and stable operation even on high-pressure conditions, there is provided a barrel-shaped centrifugal compressor including a casing, a diaphragm located in the casing to define a flow channel, and a head flange attached to the end of the casing by a shear key, wherein in the inner peripheral surface of the casing and the outer peripheral surface of abutment portions of the diaphragm and the head flange in which they are abutted on the inner peripheral surface of the casing, sliding key grooves which are vertical to the surfaces are provided at least two portions in a peripheral direction, and sliding keys are provided in the key grooves.Type: GrantFiled: June 22, 2011Date of Patent: April 14, 2015Assignee: Hitachi, Ltd.Inventors: Yohei Magara, Kazuyuki Yamaguchi, Mitsuhiro Narita, Haruo Miura, Naohiko Takahashi, Akira Endo
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Patent number: 8960009Abstract: A vibration characteristic measuring apparatus includes a magnetic bearing that generates magnetic force on the rotating body of a multi-stage centrifugal compressor, a displacement sensor that measures the vibration amplitude of the rotating body, a current amplifier that supplies a current to the magnetic bearing, and an excitation controller which outputs an excitation control signal for applying vibration to the rotating body and which measures the response characteristics of the vibration of the rotating body to the excitation control signal. The excitation controller outputs a rotating body control signal obtained by adding a vibration eliminating signal for eliminating unbalance vibration of the rotating body to the excitation control signal when measuring the response characteristics, and the current amplifier supplies a current that generates magnetic force in accordance with the rotating body control signal to the magnetic bearing.Type: GrantFiled: April 26, 2012Date of Patent: February 24, 2015Assignee: Hitachi, Ltd.Inventors: Naohiko Takahashi, Haruo Miura, Kazutoshi Yanagihara
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Publication number: 20120272740Abstract: A vibration characteristic measuring apparatus includes a magnetic bearing that generates magnetic force on the rotating body of a multi-stage centrifugal compressor, a displacement sensor that measures the vibration amplitude of the rotating body, a current amplifier that supplies a current to the magnetic bearing, and an excitation controller which outputs an excitation control signal for applying vibration to the rotating body and which measures the response characteristics of the vibration of the rotating body to the excitation control signal. The excitation controller outputs a rotating body control signal obtained by adding a vibration eliminating signal for eliminating unbalance vibration of the rotating body to the excitation control signal when measuring the response characteristics, and the current amplifier supplies a current that generates magnetic force in accordance with the rotating body control signal to the magnetic bearing.Type: ApplicationFiled: April 26, 2012Publication date: November 1, 2012Inventors: Naohiko TAKAHASHI, Haruo Miura, Kazutoshi Yanagihara
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Publication number: 20110318163Abstract: In a centrifugal compressor, for the purpose of preventing the positions of a diaphragm and a head flange in a radial direction from moving with respect to a casing, suppressing the generation of an unstable fluid force in a seal and the contact of the seal with a rotor to prevent the unstable vibration of the rotor and enabling an efficient and stable operation even on high-pressure conditions, there is provided a barrel-shaped centrifugal compressor including a casing, a diaphragm located in the casing to define a flow channel, and a head flange attached to the end of the casing by a shear key, wherein in the inner peripheral surface of the casing and the outer peripheral surface of abutment portions of the diaphragm and the head flange in which they are abutted on the inner peripheral surface of the casing, sliding key grooves which are vertical to the surfaces are provided at least two portions in a peripheral direction, and sliding keys are provided in the key grooves.Type: ApplicationFiled: June 22, 2011Publication date: December 29, 2011Inventors: Yohei Magara, Kazuyuki Yamaguchi, Mitsuhiro Narita, Haruo Miura, Naohiko Takahashi, Akira Endo
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Publication number: 20100034646Abstract: The present invention provides a centrifugal compressor that inhibits possible leakage while reducing a destabilizing fluid force generated in a seal to prevent the possible instable vibration of a rotor. The centrifugal compressor includes a casing, a rotor rotatably installed in the casing and having an impeller, and seals provided in the clearance between the casing and the rotor to prevent a fluid from leaking through the clearance from a high pressure side to a low pressure side. The rotor rotates to compress gas. For example, the balance piston seal is composed of a damper seal with a plurality of holes and a labyrinth seal with an annular parallel groove; the damper seal and the labyrinth seal are continuously provided. The damper seal is disposed on the high pressure side in a leakage flow direction. The labyrinth seal is disposed on the low pressure side in the leakage flow direction.Type: ApplicationFiled: August 3, 2009Publication date: February 11, 2010Applicant: HITACHI PLANT TECHNOLOGIES, LTD.Inventors: Yohei MAGARA, Kazuyuki YAMAGUCHI, Tetsuya KUWANO, Haruo MIURA, Naohiko TAKAHASHI
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Patent number: 6846845Abstract: A heat shock protein inducer is provided for purposes of preventing or treating ischemic disease or ischemia/reperfusion injury. This heat shock protein inducer has geranylgeranylacetone as an active ingredient and induces heat shock proteins in the heart.Type: GrantFiled: August 29, 2002Date of Patent: January 25, 2005Assignees: Eisai Co., Ltd.Inventors: Naohiko Takahashi, Tatsuhiko Ooie, Toshiie Sakata, Kunitoshi Yamanaka, Tomoko Nawata, Masaya Arikawa, Masahide Hara, Tetsunori Saikawa, Tatsuo Shimada, Hironobu Yoshimatsu
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Patent number: 6692224Abstract: A turbo compressor, comprising two (2) pieces of rotation shafts, being disposed in parallel with each other, wherein impellers are attached on both ends of one of the rotation shafts, thereby to build up a first-stage compressor and a second-stage compressor, while an impeller on one end of the other rotation shaft, thereby to build up a third-stage compressor. In a lower side of each of the compressors, an intercooler and an after-cooler are disposed in alignment with, for cooling down an operation gas compressed in each stage. The operation gas is guided into the first-stage compressor on a side opposing to a motor, into the second-stage compressor on a side of the motor, and into the third-stage compressor on the side opposing to the motor, in the order thereof.Type: GrantFiled: March 15, 2002Date of Patent: February 17, 2004Assignee: Hitachi, Ltd.Inventors: Haruo Miura, Kazuo Takeda, Naohiko Takahashi, Hideo Nishida, Hiromi Kobayashi, Tomoyuki Ishikawa
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Publication number: 20030134907Abstract: A heat shock protein inducer is provided for purposes of preventing or treating ischemic disease or ischemia/reperfusion injury. This heat shock protein inducer has geranylgeranylacetone as an active ingredient and induces heat shock proteins in the heart.Type: ApplicationFiled: August 29, 2002Publication date: July 17, 2003Inventors: Naohiko Takahashi, Tatsuhiko Ooie, Toshiie Sakata, Kunitoshi Yamanaka, Tomoko Nawata, Masaya Arikawa, Masahide Hara, Tetsunori Saikawa, Tatsuo Shimada, Hironobu Yoshimatsu
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Publication number: 20030059299Abstract: A turbo compressor, comprising two (2) pieces of rotation shafts, being disposed in parallel with each other, wherein impellers are attached on both ends of one of the rotation shafts, thereby to build up a first-stage compressor and a second-stage compressor, while an impeller on one end of the other rotation shaft, thereby to build up a third-stage compressor. In a lower side of each of the compressors, an intercooler and an after-cooler are disposed in alignment with, for cooling down an operation gas compressed in each stage. The operation gas is guided into the first-stage compressor on a side opposing to a motor, into the second-stage compressor on a side of the motor, and into the third-stage compressor on the side opposing to the motor, in the order thereof.Type: ApplicationFiled: March 15, 2002Publication date: March 27, 2003Inventors: Haruo Miura, Kazuo Takeda, Naohiko Takahashi, Hideo Nishida, Hiromi Kobayashi, Tomoyuki Ishikawa
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Patent number: 6462492Abstract: There is provided a control method capable of stably rotating a synchronous motor synchronously with an output frequency even when a phase error between a real rotary axis and a control rotary axis is large. In a phase error operating unit, from the magnitude of the motor current, the magnitude of the motor voltage, the phase difference between the motor current and the motor voltage, and the motor constants, the phase difference between the motor current and the real rotary axis is determined as the first phase difference, and the phase difference between the motor current and the virtual rotary axis is determined as the second phase difference. The difference between the first and second phase differences is defined as the phase error, and the estimation position is so modified as to make the phase error zero.Type: GrantFiled: September 5, 2000Date of Patent: October 8, 2002Assignee: Hitachi, Ltd.Inventors: Kiyoshi Sakamoto, Tsunehiro Endou, Naohiko Takahashi, Haruo Miura
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Patent number: 6396229Abstract: In a method of accurately estimating the rotor position of a synchronous motor having saliency from observable quantities, a control system for adjusting an output frequency of an inverter on the basis of a value of axis shift of the synchronous motor to operate the motor synchronously with the output frequency is provided with an induced voltage estimating/axis shift operating unit. Currents resulting from conversion of detection currents on a control axis, voltage commands to be inputted to an inverse converter and a speed command are inputted to the operating unit to estimate an induced voltage of the motor 2 and determine the axis shift from a phase of the estimated induced voltage. By using an electrical constant Lq of inductance, a voltage drop across the inductance is determined by the product of a motor speed command and magnitude of motor current. The voltage drop is a virtual quantity that does not depend on the motor rotor position.Type: GrantFiled: September 1, 2000Date of Patent: May 28, 2002Assignee: Hitachi, Ltd.Inventors: Kiyoshi Sakamoto, Tsunehiro Endou, Naohiko Takahashi, Haruo Miura, Hiroshi Fujii
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Patent number: 6369478Abstract: In an ultra-permanent-magnet-type electric rotating machine including a stator in which a winding of armatures is wound in each of a plurality of slots of a stator core, and a rotor having permanent magnets respectively inserted into permanent-magnet-inserting holes in a magnetic steel sheet ring provided at an outer periphery of a conductive and magnetic shaft, the thickness of the stator core is 0.1 to 0.2 mm, and the magnetic steel sheet ring is made of a high-tensile-strength magnetic steel sheet had tensile strength of 80 kg/mm2 or more.Type: GrantFiled: February 27, 2001Date of Patent: April 9, 2002Assignee: Hitachi, Ltd.Inventors: Haruo Koharagi, Tsukasa Taniguchi, Miyoshi Takahashi, Shinichi Wakui, Yasuo Fukushima, Haruo Miura, Naohiko Takahashi
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Patent number: 6251018Abstract: A clutch disk assembly (1) is provided between an input shaft and an output shaft to selectively transmit rotation therebetween. The clutch disk assembly (1) is provided with a dampening mechanism (4) to provide smooth transition during engagement and disengagement of the clutch disk assembly. The dampening mechanism (4) has a more durable second retaining plate (32) with a rectangular window portion for transmitting torque. This second retaining plate (32) has a second receptacle (36) to support a first spring (16). The second retaining plate (32) includes a disk-like plate main body. The second receptacle (36) is formed from that plate main body. The second receptacle (36) projects in an axial direction from the plate main body. The second receptacle (36) includes an axially supporting part (36a) and a circular supporting part (36b). The axially supporting part (36a) supports an axially outside part of the first spring (16) and continues in a radial direction.Type: GrantFiled: April 15, 1999Date of Patent: June 26, 2001Assignee: Exedy CorporationInventors: Hideki Hashimoto, Takeshi Noguchi, Naohiko Takahashi
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Patent number: 6196809Abstract: A low pressure-side first-stage compressor impeller and a high pressure-side second-stage compressor impeller are mounted respectively on opposite ends of a rotation shaft. A rotor of an electric motor for driving the two impellers is formed at a central portion of the rotation shaft. A stator of the motor is held by a motor casing. The motor casing, a first-stage compressor casing, which cooperates with the first-stage compressor impeller to form a first-stage compressor, and a second-stage compressor casing, which cooperates with the second-stage compressor impeller to form a second-stage compressor, are cast into an integral construction. This integral casing is further formed integrally with an intermediate cooler, disposed downstream of the first-stage compressor, and a discharge cooler disposed downstream of the second-stage compressor.Type: GrantFiled: February 13, 1998Date of Patent: March 6, 2001Assignee: Hitachi, Ltd.Inventors: Kazuki Takahashi, Haruo Miura, Hideo Nishida, Naohiko Takahashi, Yasuo Fukushima
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Patent number: 6138811Abstract: A spline hub 6 is formed with a cylindrical boss (11) configured for engagement with a shaft extending from, for instance, a transmission. Axial spline grooves and circumferential grease grooves (14) are formed on the inner peripheral surface of the boss (11). A first axial end surface (14) of the grease groove (14) is tapered.Type: GrantFiled: May 19, 1999Date of Patent: October 31, 2000Assignee: Exedy CorporationInventors: Hideki Hashimoto, Naohiko Takahashi, Katsutoshi Seino