Patents by Inventor Kazuto Sakai
Kazuto Sakai 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: 11050373Abstract: A rotary electric system includes a rotary electric device that includes: a stator including a stator winding; and a rotor. The stator winding includes: a first coil group that generates a rotating magnetic field to rotate the rotor; and a second coil group that generates power with induced electromotive force due to rotation of the rotor.Type: GrantFiled: March 1, 2018Date of Patent: June 29, 2021Assignee: Toshiba Industrial Products and Systems CorporationInventor: Kazuto Sakai
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Publication number: 20190379312Abstract: A rotary electric system includes a rotary electric device that includes: a stator including a stator winding; and a rotor. The stator winding includes: a first coil group that generates a rotating magnetic field to rotate the rotor; and a second coil group that generates power with induced electromotive force due to rotation of the rotor.Type: ApplicationFiled: March 1, 2018Publication date: December 12, 2019Applicant: Toshiba Industrial Products and Systems CorporationInventor: Kazuto SAKAI
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Patent number: 9680406Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.Type: GrantFiled: March 5, 2014Date of Patent: June 13, 2017Assignee: Kabushiki Kaisha ToshibaInventors: Kazuaki Yuuki, Kazuto Sakai, Hiroshi Mochikawa
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Patent number: 9496774Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.Type: GrantFiled: June 4, 2014Date of Patent: November 15, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yutaka Hashiba, Kazuto Sakai, Norio Takahashi, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Motoyasu Mochizuki, Tadashi Tokumasu
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Patent number: 9490684Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.Type: GrantFiled: June 4, 2014Date of Patent: November 8, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yutaka Hashiba, Kazuto Sakai, Norio Takahashi, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Motoyasu Mochizuki, Tadashi Tokumasu
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Patent number: 9373992Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.Type: GrantFiled: June 4, 2014Date of Patent: June 21, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yutaka Hashiba, Kazuto Sakai, Norio Takahashi, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Motoyasu Mochizuki, Tadashi Tokumasu
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Patent number: 8884576Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.Type: GrantFiled: August 20, 2013Date of Patent: November 11, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Kazuaki Yuuki, Kazuto Sakai, Hiroshi Mochikawa
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Patent number: 8860356Abstract: A variable magnetic flux motor drive system includes: a variable magnetic flux motor having a variable magnet which is a low-coercive permanent magnet; an inverter that drives the variable magnetic flux motor 1; an inverter as a magnetization unit which supplies a magnetization current for controlling a magnetic flux of the variable magnet; and a boosting unit boosting an input DC voltage to a predetermined target value to output it to the inverter. The variable magnetic flux motor drive system makes it possible to achieve size reduction and high efficiency, while securing a voltage required for supplying a magnetization current when controlling the magnetic flux of the variable magnet.Type: GrantFiled: September 16, 2008Date of Patent: October 14, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Kazuaki Yuuki, Kazuto Sakai, Hiroshi Mochikawa
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Publication number: 20140285051Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.Type: ApplicationFiled: June 4, 2014Publication date: September 25, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yutaka Hashiba, Kazuto Sakai, Norio Takahashi, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Motoyasu Mochizuki, Tadashi Tokumasu
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Publication number: 20140283372Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.Type: ApplicationFiled: June 4, 2014Publication date: September 25, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yutaka HASHIBA, Kazuto SAKAI, Norio TAKAHASHI, Kazuaki YUUKI, Masanori ARATA, Yusuke MATSUOKA, Motoyasu MOCHIZUKI, Tadashi TOKUMASU
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Publication number: 20140283374Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.Type: ApplicationFiled: June 4, 2014Publication date: September 25, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yutaka HASHIBA, Kazuto Sakai, Norio Takahashi, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Motoyasu Mochizuki, Tadashi Tokumasu
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Patent number: 8796898Abstract: According to one embodiment, a rotor is configured by a rotor core and magnetic poles. Two or more types of permanent magnets are used such that each product of coercivity and thickness in the magnetization direction becomes different. A stator is located outside the rotor with air gap therebetween and configured by an armature core winding. At least one permanent magnet is magnetized by a magnetic field by a current of the armature winding to change a magnetic flux content thereof irreversibly. A short circuited coil is provided to surround a magnetic path portion of the other permanent magnet excluding the magnet changed irreversibly and a portion adjacent to the other permanent magnet where the magnetic flux leaks. A short-circuit current is generated in the short circuited coil by the magnetic flux generated by conducting a magnetization current to the winding. A magnetic field is generated by the short-circuit current.Type: GrantFiled: December 15, 2009Date of Patent: August 5, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Yutaka Hashiba, Kazuto Sakai, Norio Takahashi, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Motoyasu Mochizuki, Tadashi Tokumasu
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Publication number: 20140184133Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.Type: ApplicationFiled: March 5, 2014Publication date: July 3, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Kazuaki Yuuki, Kazuto Sakai, Hiroshi Mochikawa
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Patent number: 8674575Abstract: An increase of the magnetization current can be restrained during demagnetization and magnetization, and a variable speed operation can be achieved at a high power output over a wide range of from a low speed to a high speed. A rotor 1 is configured by a rotor core 2, permanent magnets 3 having a small value as the product of the coercivity and the thickness in the magnetization direction thereof, and permanent magnets 4 having a large value as the product. When reducing a flux linkage of the permanent magnets 3, a magnetic field directed to the reverse direction of the magnetization direction of the permanent magnets 3 due to a current of an armature coil is caused to act on them. When increasing a flux linkage of the permanent magnets 3, a magnetic field directed to the same direction as the magnetization direction of the permanent magnets 3 due to a current of an armature coil is caused to act on them.Type: GrantFiled: June 19, 2009Date of Patent: March 18, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Kazuto Sakai, Yutaka Hashiba, Yosuke Otsubo, Yusuke Matsuoka, Norio Takahashi, Tadashi Tokumasu
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Patent number: 8653710Abstract: A rotor has rotor cores divided in the axial direction. A permanent magnet is mounted at the position of each of the magnetic poles of cores. The permanent magnet of each magnetic pole is configured by a single tabular member that penetrates the two divided cores in the axial direction. Convex parts are respectively provided on the outer peripheries of the respective magnetic poles of the rotor cores along the axial direction of the rotor. The convex parts are provided to positions that are displaced for each of the two divided cores. The magnetic flux density increases in the convex parts, which becomes the magnetic pole center. Since the convex parts positions are displaced to each other, a skew function can be exhibited even if the permanent magnet is mounted at the same position.Type: GrantFiled: December 16, 2009Date of Patent: February 18, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Norio Takahashi, Kazuto Sakai, Yutaka Hashiba, Kazuaki Yuuki, Masanori Arata, Yusuke Matsuoka, Tadashi Tokumasu
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Patent number: 8624457Abstract: An increase of the magnetization current can be prevented during demagnetization and magnetization, and a variable speed operation can be achieved at a high power output over a wide range of from a low speed to a high speed. A rotor (1) is configured by a rotor core (2), a variable magnetic force magnet (3) and a fixed magnetic force magnet (4). A variable magnetic force magnet (3) and a fixed magnetic force magnet (4a) are overlapped in the magnetization direction thereof to form a series of magnets. The series of magnets is located within the rotor core at a position where the magnetization direction is in the direction of a d-axis. On either side of the series of magnets of the variable magnetic force magnet (3) and the fixed magnetic force magnet (4a), fixed magnetic force magnets (4b, 4b) are located at a position where the magnetization direction is in the direction of the d-axis.Type: GrantFiled: November 19, 2009Date of Patent: January 7, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Kazuto Sakai, Yutaka Hashiba, Norio Takahashi, Kazuaki Yuuki
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Publication number: 20130334991Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.Type: ApplicationFiled: August 20, 2013Publication date: December 19, 2013Applicant: Kabushiki Kaisha ToshibaInventors: Kazuaki YUUKI, Kazuto Sakai, Hiroshi Mochikawa
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Patent number: 8569921Abstract: According to one embodiment, a permanent-magnet type electric rotating machine has a stator, a magnetizing coil, a rotor and a case. The stator has an armature coil configured to form a magnetic circuit for driving. The magnetizing coil is configured to form a magnetic circuit for magnetizing. The rotor has a constant magnetized magnet, a rotor core and a variable magnetized magnet. The rotor core holds the constant magnetized magnet. The constant magnetized magnet is arranged closer to the magnetic circuit for driving than the variable magnetized magnet. The variable magnetized magnet is arranged closer to the magnetic circuit for magnetizing than the constant magnetized magnet.Type: GrantFiled: February 23, 2012Date of Patent: October 29, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Kazuto Sakai, Yutaka Hashiba, Norio Takahashi, Kazuaki Yuuki, Makoto Matsushita, Daisuke Misu, Masanori Arata, Tadashi Tokumasu, Motoyasu Mochizuki, Kuniyuki Araki
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Patent number: 8552678Abstract: A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.Type: GrantFiled: March 20, 2012Date of Patent: October 8, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Kazuaki Yuuki, Kazuto Sakai, Hiroshi Mochikawa
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Patent number: 8362668Abstract: A rotor for a rotating electrical machine suppresses demagnetization of permanent magnets without deteriorating motor characteristics, is low-cost, and is highly reliable. The rotor has a plurality of rotor cores that are stacked together, a plurality of permanent magnets axially divided by the rotor cores and circumferentially arranged on each of the rotor cores, to circumferentially form magnetic irregularities, and a rotor blank made of nonmagnetic material arranged between those of the rotor cores that are adjacent to each other.Type: GrantFiled: November 25, 2008Date of Patent: January 29, 2013Assignees: Kabushiki Kaisha Toshiba, Toshiba Industrial Products Manufacturing CorporationInventors: Norio Takahashi, Mikio Takabatake, Masanori Arata, Kazuto Sakai, Yutaka Hashiba, Wataru Ito, Tadashi Tokumasu, Masakatsu Matsubara