Patents by Inventor Takashi Tokizawa
Takashi Tokizawa 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: 11218037Abstract: A rotating electrical machine having holding surfaces on a pair of housings which firmly holds a stator core made of a core stack. The holding surfaces have a small-diameter first annular surface and a large-diameter second annular surface arranged at different locations in the axial direction. The surfaces in contact with inner and outer circumferential regions of a yoke hold the core. Two contacts between the housing and core are in different locations on a radial and axial direction. An outer peripheral side of the yoke where plate thickness is smaller and an inner peripheral side where plate thickness is larger are pressed individually in the axial direction. A firm holding feature suitable for configuration of the yoke is ensured to setting a difference in level between the contacts Eliminating problems about gaps created between layers of the core stack without any changes to the structure of the core stack.Type: GrantFiled: November 7, 2016Date of Patent: January 4, 2022Assignee: DENSO CORPORATIONInventor: Takashi Tokizawa
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Patent number: 10181776Abstract: There is provided a winding to be wound at a stator of a rotary electric machine. The winding is produced from a flat wire having a rectangular cross section along a plane perpendicular to a length-wise direction. The flat wire is coated with an electric insulating layer and is bent to have curves at given portions of the flat wire in the length-wise direction. The curves are located on an axial outer side of the stator. The cross section of the flat wire has four corners, among which mutually-adjacent two corners are lager in curvatures than remaining mutually-adjacent two corners. The mutually-adjacent two corners whose curvatures are smaller are positioned on a circumferential outer side of each of the curves and the mutually-adjacent two corners whose curvatures are larger are positioned on a circumferential inner side of each of the curves.Type: GrantFiled: March 15, 2017Date of Patent: January 15, 2019Assignee: DENSO CORPORATIONInventor: Takashi Tokizawa
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Publication number: 20180331587Abstract: A rotating electrical machine having holding surfaces on a pair of housings which firmly holds a stator core made of a core stack. The holding surfaces have a small-diameter first annular surface and a large-diameter second annular surface arranged at different locations in the axial direction. The surfaces in contact with inner and outer circumferential regions of a yoke hold the core. Two contacts between the housing and core are in different locations on a radial and axial direction. An outer peripheral side of the yoke where plate thickness is smaller and an inner peripheral side where plate thickness is larger are pressed individually in the axial direction. A firm holding feature suitable for configuration of the yoke is ensured to setting a difference in level between the contacts Eliminating problems about gaps created between layers of the core stack without any changes to the structure of the core stack.Type: ApplicationFiled: November 7, 2016Publication date: November 15, 2018Applicant: DENSO CORPORATIONInventor: Takashi TOKIZAWA
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Patent number: 9899887Abstract: A stator includes a multi-phase stator coil comprised of phase windings. Each of the phase windings is formed of a continuous electric conductor and includes in-slot portions and coil end portions. Each of the in-slot portions is received in one of slots of a stator core. Each of the coil end portions is located outside the slots so as to connect one adjacent pair of the in-slot portions. Each of the coil end portions includes at least one oblique part that extends obliquely at an oblique angle with respect to either an axial direction or a circumferential direction of the stator core. The oblique angles of the oblique parts of the coil end portions in at least one of the phase windings of the stator coil are set to be different from the oblique angles of the oblique parts of the coil end portions in the other phase windings.Type: GrantFiled: January 21, 2015Date of Patent: February 20, 2018Assignee: DENSO CORPORATIONInventor: Takashi Tokizawa
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Publication number: 20170187270Abstract: There is provided a winding to be wound at a stator of a rotary electric machine. The winding is produced from a flat wire having a rectangular cross section along a plane perpendicular to a length-wise direction. The flat wire is coated with an electric insulating layer and is bent to have curves at given portions of the flat wire in the length-wise direction. The curves are located on an axial outer side of the stator. The cross section of the flat wire has four corners, among which mutually-adjacent two corners are lager in curvatures than remaining mutually-adjacent two corners. The mutually-adjacent two corners whose curvatures are smaller are positioned on a circumferential outer side of each of the curves and the mutually-adjacent two corners whose curvatures are larger are positioned on a circumferential inner side of each of the curves.Type: ApplicationFiled: March 15, 2017Publication date: June 29, 2017Applicant: DENSO CORPORATIONInventor: Takashi TOKIZAWA
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Patent number: 9419484Abstract: A stator includes an annular stator core and a stator coil. The stator coil is formed of electric conductor segments each of which is bent in its thickness direction to include, at least, an in-slot portion and an oblique portion. The in-slot portion is received in a corresponding slot of the stator core with its width direction coinciding with a radial direction of the stator core. The oblique portion protrudes from the in-slot portion outside the corresponding slot and extends, over its entire length, along the circumferential direction of the stator core obliquely with respect to an axial end face of the stator core. The oblique portion includes a thick section on the proximal side and a thin section on the distal side. Each corresponding pair of the oblique portions of the electric conductor segments are connected by joining the thin sections of the oblique portions.Type: GrantFiled: March 31, 2014Date of Patent: August 16, 2016Assignee: DENSO CORPORATIONInventor: Takashi Tokizawa
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Publication number: 20150229174Abstract: A stator includes a multi-phase stator coil comprised of phase windings. Each of the phase windings is formed of a continuous electric conductor and includes in-slot portions and coil end portions. Each of the in-slot portions is received in one of slots of a stator core. Each of the coil end portions is located outside the slots so as to connect one adjacent pair of the in-slot portions. Each of the coil end portions includes at least one oblique part that extends obliquely at an oblique angle with respect to either an axial direction or a circumferential direction of the stator core. The oblique angles of the oblique parts of the coil end portions in at least one of the phase windings of the stator coil are set to be different from the oblique angles of the oblique parts of the coil end portions in the other phase windings.Type: ApplicationFiled: January 21, 2015Publication date: August 13, 2015Inventor: Takashi TOKIZAWA
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Publication number: 20140300237Abstract: A stator includes an annular stator core and a stator coil. The stator coil is formed of electric conductor segments each of which is bent in its thickness direction to include, at least, an in-slot portion and an oblique portion. The in-slot portion is received in a corresponding slot of the stator core with its width direction coinciding with a radial direction of the stator core. The oblique portion protrudes from the in-slot portion outside the corresponding slot and extends, over its entire length, along the circumferential direction of the stator core obliquely with respect to an axial end face of the stator core. The oblique portion includes a thick section on the proximal side and a thin section on the distal side. Each corresponding pair of the oblique portions of the electric conductor segments are connected by joining the thin sections of the oblique portions.Type: ApplicationFiled: March 31, 2014Publication date: October 9, 2014Applicant: DENSO CORPORATIONInventor: Takashi TOKIZAWA
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Publication number: 20140132104Abstract: There is provided a winding to be wound at a stator of a rotary electric machine. The winding is produced from a flat wire having a rectangular cross section along a plane perpendicular to a length-wise direction. The flat wire is coated with an electric insulating layer and is bent to have curves at given portions of the flat wire in the length-wise direction. The curves are located on an axial outer side of the stator. The cross section of the flat wire has four corners, among which mutually-adjacent two corners are lager in curvatures than remaining mutually-adjacent two corners. The mutually-adjacent two corners whose curvatures are smaller are positioned on a circumferential outer side of each of the curves and the mutually-adjacent two corners whose curvatures are larger are positioned on a circumferential inner side of each of the curves.Type: ApplicationFiled: November 15, 2013Publication date: May 15, 2014Inventor: Takashi TOKIZAWA
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Patent number: 8624459Abstract: A rotor of alternator has core layer units serially located along axial direction. Each unit has a field coil generating magnetic flux and two rotor cores receiving the flux on respective sides of the coil in axial direction. Each core has a first yoke portion located on inner side of the coil, a second yoke portion extending from the first yoke portion toward the outer side and magnetic poles extending from the second yoke portion in the axial direction. The poles of one core and the poles of the other core in each unit extend toward different axial sides and are alternately arranged in circumferential direction on the outer side of the coil. A ratio of the outer circumferential diameter of the first yoke portions to the rotational diameter of the poles is lower than 0.54.Type: GrantFiled: March 3, 2011Date of Patent: January 7, 2014Assignee: Denso CorporationInventor: Takashi Tokizawa
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Patent number: 8427026Abstract: A stator core manufacturing method has a winding process including an L-bending process in which an outer edge of a strip of steel sheet is bent at an angle to a general plane of the strip, an edgewise-bending process in which the outer edge of the strip is bent edgewise into an arc, and a roll-bending process in which the outer edge of the strip is bent into a curve warping in a thickness direction of the strip, wherein the L-bending process, the edgewise-bending process and the roll-bending process are performed successively in a predetermined sequence before the strip is wound in a spiral fashion so as to form a generally cylindrical core.Type: GrantFiled: September 29, 2008Date of Patent: April 23, 2013Assignee: Denso CorporationInventor: Takashi Tokizawa
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Patent number: 8302286Abstract: A stator winding is manufactured by a forming step, a winding step, and a expanding step. In the forming step, an S-shaped offset shape is formed on a conductor part corresponding to a coil end part. Thereby, in a coil end part, it is possible to provide an expected shape stably at the coil end part. The conductor is wound around a bobbin in the winding step. In the winding step, a twisted shape is given to the conductor parts to be the inclined part of the coil end and the conductor part to be accommodated in a slot. In the expanding step, a preform product removed from the bobbin is expanded into a shape of the stator winding.Type: GrantFiled: September 29, 2009Date of Patent: November 6, 2012Assignee: Denso CorporationInventor: Takashi Tokizawa
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Patent number: 8291573Abstract: A stator has conductor segments serially wound on a core. Each segment inserted in one of slots of the core has a slanting portion protruding from the slot and inclined toward circumferential and axial directions of the core. Each slanting portion has an oblique portion with a film removal surface and a film removal portion with a film removed surface to have a slanting removal area covered with no insulation film and extending on the oblique portion. Each film removal portion has a connection portion on an end thereof. The connection portions are aligned along a radial direction of the core to form a plurality of end pairs. The connection portions of each end pair are connected with each other so as to serially connect the segments with one another.Type: GrantFiled: October 26, 2010Date of Patent: October 23, 2012Assignee: Denso CorporationInventor: Takashi Tokizawa
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Patent number: 8061015Abstract: In a method of manufacturing a stator core of an electric rotating machine, a cylindrical laminated core is formed by thinning a side portion of a steel plate with magnetic pole teeth and helically winding the steel sheet, and the stator core is manufactured by performing ironing for the laminated core. This laminated core has steel sheets aligned along the axial direction thereof, and the sheets have respective thinned outer end portions spaced apart from one another on the outer side of the laminated core. In the ironing, the thinned outer end portions of the steel sheets are brought into contact with one another in a forming apparatus, and an ironing load is given to the thinned outer end portions to shorten lengths of the thinned outer end portions in the radial direction of the laminated core at a predetermined value.Type: GrantFiled: September 22, 2008Date of Patent: November 22, 2011Assignee: Denso CorporationInventor: Takashi Tokizawa
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Publication number: 20110241471Abstract: A rotor of alternator has core layer units serially located along axial direction. Each unit has a field coil generating magnetic flux and two rotor cores receiving the flux on respective sides of the coil in axial direction. Each core has a first yoke portion located on inner side of the coil, a second yoke portion extending from the first yoke portion toward the outer side and magnetic poles extending from the second yoke portion in the axial direction. The poles of one core and the poles of the other core in each unit extend toward different axial sides and are alternately arranged in circumferential direction on the outer side of the coil. A ratio of the outer circumferential diameter of the first yoke portions to the rotational diameter of the poles is lower than 0.54.Type: ApplicationFiled: March 3, 2011Publication date: October 6, 2011Applicant: DENSO CORPORATIONInventor: Takashi TOKIZAWA
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Patent number: 7986072Abstract: A stator core of an electric rotating machine has steel sheets formed of a steel plate wound in the cylindrical shape. Each sheet has teeth disposed along the circumferential direction of the core on the inner side of the sheet, divided end portions disposed along the circumferential direction on the outer side of the sheet, slits alternately disposed with the divided end portions along the circumferential direction, and a boundary portion disposed between the group of teeth and the group of divided end portions. The teeth and the divided end portions substantially have the same constant thickness. The boundary portion has a changing thickness decreased toward the outer side.Type: GrantFiled: September 29, 2008Date of Patent: July 26, 2011Assignee: Denso CorporationInventor: Takashi Tokizawa
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Patent number: 7958621Abstract: A method of manufacturing a rotor for a rotating electrical machine includes the steps of: preparing a first and a second pole core, a rotary shaft, and a field coil; press-fitting the rotary shaft into a through-hole of the first pole core so that the axes of the rotary shaft and the through-hole coincide with each other; mounting the field coil on one of the first and second pole cores; opposing the first and second pole cores to each other so that the axes of the through-holes thereof are in alignment with each other and contact surfaces thereof face each other with a maximum parallelism therebetween; press-fitting the second pole core onto the rotary shaft so that the contact surfaces of the first and second pole cores maximally contact with each other and the axis of the rotary shaft coincides with the axes of the through-holes of the pole cores.Type: GrantFiled: June 12, 2007Date of Patent: June 14, 2011Assignee: Denso CorporationInventor: Takashi Tokizawa
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Patent number: 7956507Abstract: In a rotor for a rotating electrical machine, a flange of an insulating bobbin is formed with a first hook portion and a second hook portion. The first hook portion directs a lead of a field coil both against the winding direction of the field coil and radially inward. The first hook portion has a first groove in which is hooked a proximal portion of the lead. The second hook portion directs the lead axially outward. The second hook portion has a second groove which has an open end on a radially inner periphery of the second hook portion, a closed end positioned radially outward of the open end, and a neck between the open and closed ends. The second hook portion has an intermediate portion of the lead hooked in the second groove between the neck and closed end of the second groove.Type: GrantFiled: March 19, 2009Date of Patent: June 7, 2011Assignee: Denso CorporationInventor: Takashi Tokizawa
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Publication number: 20110041320Abstract: A stator has conductor segments serially wound on a core. Each segment inserted in one of slots of the core has a slanting portion protruding from the slot and inclined toward circumferential and axial directions of the core. Each slanting portion has an oblique portion with a film removal surface and a film removal portion with a film removed surface to have a slanting removal area covered with no insulation film and extending on the oblique portion. Each film removal portion has a connection portion on an end thereof. The connection portions are aligned along a radial direction of the core to form a plurality of end pairs. The connection portions of each end pair are connected with each other so as to serially connect the segments with one another.Type: ApplicationFiled: October 26, 2010Publication date: February 24, 2011Applicant: DENSO CORPORATIONInventor: Takashi Tokizawa
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Patent number: 7847465Abstract: A stator has conductor segments serially wound on a core. Each segment inserted in one of slots of the core has a slanting portion protruding from the slot and inclined toward circumferential and axial directions of the core. Each slanting portion has an oblique portion with a film removal surface and a film removal portion with a film removed surface to have a slanting removal area covered with no insulation film and extending on the oblique portion. Each film removal portion has a connection portion on an end thereof. The connection portions are aligned along a radial direction of the core to form a plurality of end pairs. The connection portions of each end pair are connected with each other so as to serially connect the segments with one another.Type: GrantFiled: February 8, 2008Date of Patent: December 7, 2010Assignee: Denso CorporationInventor: Takashi Tokizawa