Patents by Inventor Minoru Ishijima
Minoru Ishijima 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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Publication number: 20080248884Abstract: The pocket 4a of the retainer 4 comprises a pair of axial walls 4a1 opposed in the axial direction of the retainer 4, a pair of circumferential walls 4a2 opposed in the circumferential direction, and corner round sections 4a3 connecting the axial wall 4a1 and the circumferential wall 4a2. The ratio (R/d) of the radius of curvature R of the corner round section 4a3 to the diameter d of the torque transmission ball 3 is set in a range of 0.45?R/d?0.62. Also, the circumferential wall 4a2 and the corner round sections 4a3 are drawn in a single arc with the radius of curvature R. Furthermore, as to the axial walls 4a1, grinding, cutting by quenched steel, or the like is carried out after the heat treatment (carburizing and quenching) of the retainer 4 in order to reduce variations in a processing margin.Type: ApplicationFiled: December 17, 2004Publication date: October 9, 2008Inventors: Minoru Ishijima, Kenta Yamazaki
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Publication number: 20080194341Abstract: A tripod type constant velocity universal joint that includes an outer joint member having three track grooves axially extending on an inner circumferential surface thereof; an inner joint member having three radially projecting trunnions; a boot fitted to an outer periphery of the outer joint member at an end portion and to a shaft extended from the inner joint member at another end portion to seal an inner region of the joint; wherein the outer joint member includes a first reduced-thickness portion on an outer periphery thereof in a region corresponding to the region between the track grooves, and a second reduced-thickness portion on an outer periphery thereof in a region corresponding to the region where the track grooves are located; and wherein the second reduced-thickness portion is of a groove shape axially extending with respect to the outer joint member.Type: ApplicationFiled: April 11, 2008Publication date: August 14, 2008Applicant: NTN CORPORATIONInventors: Junichi Izumino, Minoru Ishijima
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Publication number: 20080161116Abstract: A tripod type constant velocity joint comprising a hollow cylindrical housing fixed to the end of a first rotary shaft and formed at the inner peripheral surface thereof with axially extending recessed grooves opened at one axial end and located at circumferentially trisectional positions on the inner peripheral surface, a tripod consisting of a boss fixed to the end of a second rotary shaft, and end-spherical trunnion journals radially projecting from circumferentially trisectional positions on the boss, a roller assemblies each consisting of an inner roller swingably fitted at the inner peripheral surface thereof on the spherical outer peripheral surface of the trunnion journal, and an outer roller supported for rotation and axial movement on the outer peripheral surface of the inner roller through needle rollers, wherein the outer rollers are received in the recessed grooves in the housing and are rollable axially of the housing, each recessed groove consists of guide surfaces contacting the outer peripherType: ApplicationFiled: March 14, 2008Publication date: July 3, 2008Inventors: Minoru Ishijima, Kenta Yamazaki, Junichi Izumino
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Publication number: 20080096678Abstract: A fixed type constant velocity joint comprising an outer ring (1), an inner ring (2), torque transmitting balls (3), a cage (4), and a preloading mechanism in which either a pressing section for axially applying an elastic pressing force or a receiving section for receiving the pressing force from the pressing section is disposed in the cage (4), the other being disposed in the inner ring (2). The axial clearance between the inner ring (2) and the cage (4) is greater than the axial clearance which is due to the radial clearance of the track, and the axial clearance which is produced by the radial clearance of the track is 2.5-6.5 times as large as the radial clearance of the track. Further, the center of the outer spherical surface (2b) of the inner ring (2) is shifted to the spread side of the ball tracks (1a, 2a) over the center of the inner spherical surface (4b) of the cage, thereby improving the cross operation.Type: ApplicationFiled: September 27, 2004Publication date: April 24, 2008Inventors: Kenta Yamazaki, Minoru Ishijima
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Patent number: 7357723Abstract: A tripod type constant velocity joint comprising a hollow cylindrical housing fixed to the end of a first rotary shaft and formed at the inner peripheral surface thereof with axially extending recessed grooves opened at one axial end and located at circumferentially trisectional positions on the inner peripheral surface, a tripod consisting of a boss fixed to the end of a second rotary shaft, and end-spherical trunnion journals radially projecting from circumferentially trisectional positions on the boss, a roller assemblies each consisting of an inner roller swingably fitted at the inner peripheral surface thereof on the spherical outer peripheral surface of the trunnion journal, and an outer roller supported for rotation and axial movement on the outer peripheral surface of the inner roller through needle rollers, wherein the outer rollers are received in the recessed grooves in the housing and are rollable axially of the housing, each recessed groove consists of guide surfaces contacting the outer peripherType: GrantFiled: September 5, 2006Date of Patent: April 15, 2008Assignee: NTN CorporationInventors: Minoru Ishijima, Kenta Yamazaki, Junichi Izumino
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Publication number: 20080051203Abstract: It is arranged that in a fixed type constant velocity joint 1 having a plurality of torque transmitting ball tacks 30, the torsional angle at the input torque 0 Nm in a torque-torsional angle diagram be approximately 0. Further, the torsional rigidity in the vicinity of input torque 0 Nm in the torque-torsional angle diagram is placed in a range of 1.5 Nm/deg to 6 Nm/deg.Type: ApplicationFiled: December 28, 2004Publication date: February 28, 2008Inventors: Minoru Ishijima, Kenta Yamazaki
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Publication number: 20070293327Abstract: The present invention aims to achieve the high rigidity and light weight of a connecting shaft of a constant velocity universal joint, and to reduce manufacturing costs. A hollow connecting shaft 5 is provided with an axial end section 5c having teeth 5c which are engaged with an engagement section 2d of an inner member 2, and a middle section 5d continued from the axial end section 5c. To mold the connecting shaft 5, both end sections of a pipe material with an outside diameter dm are drawn, and then the teeth (splines or serrations) 5c are molded in the outer periphery of the drawing-molded axial end section 5c on an axial end side by form rolling or the like. The outside diameter of the axial end section 5c is ds, and the outside diameter of the middle section 5d is dm as with that of the pipe material (ds<dm).Type: ApplicationFiled: December 17, 2004Publication date: December 20, 2007Inventors: Minoru Ishijima, Kenta Yamazaki
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Publication number: 20070280778Abstract: The present invention provides a fixed type constant velocity universal joint suitable for applications where vibration is harmful. A fixed-type constant velocity universal joint (1) includes an inner member (20) fitted in an outer member (10) with a retainer (40) therebetween, and balls (30) provided between track grooves (14, 24) of the outer member (10) and the inner member (20) as well as retained by the retainer (40). The outer member (10) is constructed as a multilayer structure of three or more layers formed of an outside member (15), one or a plurality of intermediate members (16), and an inside member (17), and at least one of the intermediate members (16) is constructed of an elastic material. Cushioning action of the intermediate members (16) can reliably absorb vibration transmitted from either of the outer member (10) and the inner members (20) with the members (10, 20) set to a predetermined operation angle.Type: ApplicationFiled: December 8, 2004Publication date: December 6, 2007Inventors: Kenta Yamazaki, Minoru Ishijima
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Publication number: 20070099801Abstract: The present invention provides a grease composition for use in constant velocity joints, which comprises the following components (a) to (g) and a constant velocity joint comprising the grease composition sealed or encapsulated therein: (a) a base oil; (b) a diurea thickener represented by the following general formula: R1NH—CO—NH—C6H4-p-CH2—C6H4-p-NH—CO—NHR2 wherein R1 and R2 each independently represents an alkyl group having 8 to 20 carbon atoms, an aryl group having 6 to 12 carbon atoms or a cycloalkyl group having 6 to 12 carbon atoms; (c) a molybdenum dialkyl dithiocarbamate insoluble in the base oil; (d) a molybdenum dialkyl dithiocarbamate soluble in the base oil; (e) molybdenum disulfide; (f) at least one member selected from the group consisting of calcium phenate and calcium sulfonate; and (g) a sulfur-containing extreme-pressure agent free of phosphorus.Type: ApplicationFiled: December 21, 2006Publication date: May 3, 2007Applicants: Kyodo Yushi Co., Ltd., NTN CorporationInventors: Mitsuhiro Kakizaki, Takashi Okaniwa, Minoru Ishijima, Shinichi Takabe
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Publication number: 20070049382Abstract: A constant velocity universal joint shaft, capable of suppressing a rotational backlash when incorporated in the constant velocity universal joint, and improving the assembly efficiency as well as reducing the manufacturing cost, is to be provided. The present invention relates to the constant velocity universal joint shaft having a spline that fits an inner race of the constant velocity universal joint. The shaft includes a shaft body with a spline formed thereon, and a yoke portion with a ring-shaped fitting portion. The shaft body and the yoke portion are integrally formed of medium carbon steel. By a pressing force of a pressing member the fitting portion of the yoke portion is tightened, so that such fitting portion fits a shaft external to the joint. In the constant velocity universal joint, the pressing member and an abutment member are elastically butted via an elastic member, so that a ball constantly remains in contact with a raceway of an outer member and a raceway of an inner member.Type: ApplicationFiled: August 9, 2006Publication date: March 1, 2007Inventors: Minoru Ishijima, Kenta Yamazaki
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Publication number: 20070004522Abstract: A tripod type constant velocity joint comprising a hollow cylindrical housing fixed to the end of a first rotary shaft and formed at the inner peripheral surface thereof with axially extending recessed grooves opened at one axial end and located at circumferentially trisectional positions on the inner peripheral surface, a tripod consisting of a boss fixed to the end of a second rotary shaft, and end-spherical trunnion journals radially projecting from circumferentially trisectional positions on the boss, a roller assemblies each consisting of an inner roller swingably fitted at the inner peripheral surface thereof on the spherical outer peripheral surface of the trunnion journal, and an outer roller supported for rotation and axial movement on the outer peripheral surface of the inner roller through needle rollers, wherein the outer rollers are received in the recessed grooves in the housing and are rollable axially of the housing, each recessed groove consists of guide surfaces contacting the outer peripherType: ApplicationFiled: September 5, 2006Publication date: January 4, 2007Inventors: Minoru Ishijima, Kenta Yamazaki, Junichi Izumino
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Patent number: 7137895Abstract: Tripod type constant velocity joint has a hollow cylindrical housing fixed to the end of a first shaft and has axially extending recessed grooves opened at one axial end and located at circumferentially trisectional positions on an inner peripheral surface. A tripod has a boss fixed to the end of a second shaft with end-spherical trunnion journals radially projecting from circumferentially trisectional positions on the boss. Roller assemblies each have an inner roller fitted on the spherical surface of the trunnion journal and an outer roller supported for rotation and axial movement on the inner roller. The outer rollers are received in the recessed grooves and rollable axially of the housing. Each recessed groove has guide surfaces contacting the outer surface of the outer roller. Guide shoulder surfaces guide the outer roller axially of the housing. A relief is locally formed along a forged parting line of the trunnion journal.Type: GrantFiled: October 21, 2003Date of Patent: November 21, 2006Assignee: NTN CorporationInventors: Minoru Ishijima, Kenta Yamazaki, Junichi Izumino
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Patent number: 7121950Abstract: A tripod type constant velocity universal joint that can suppress generation of shudder by reducing the 3rd order cyclic axial force and has high rotation durability. In a double-roller tripod type constant velocity universal joint, a track gap ?1 between one of the roller guiding surfaces formed on both sides of a track groove, which is on the no-load applied side, and an outer circumferential surface of an outer roller is set to satisfy ?1>0.03/A. Also, a shoulder gap ?2 between a guide shoulder surface formed at the bottom of the track groove and a side surface of the outer roller is set to satisfy ?2>0.15×A. In both the expressions, a degree of torus A is defined as a ratio of a radius of curvature r of a generatrix of the outer circumferential surface to a radius R of an outer circumference of the outer roller (A=r/R).Type: GrantFiled: November 4, 2004Date of Patent: October 17, 2006Assignee: NTN CorporationInventors: Junichi Izumino, Minoru Ishijima, Kenta Yamazaki
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Publication number: 20060223642Abstract: The present invention provides a lightweight, compact, and low-cost tripod type constant velocity universal joint while maintaining strength of overall tripod type constant velocity universal joint. The dimensional ratio of each component of the tripod type constant velocity universal joint is set as follows: 0.80<Dor<0.90, 0.105<Tor<0.115, 0.025<t1r<0.045, 0.025<t2r<0.075, 0.53<Dir<0.63, 0.065<Tir<0.085, 0.32<Dj1r<0.42, and 0.32<Dj2r<0.35. In this event, the subscript “r” means that each dimension is divided by the trunnion journal pitch circle diameter D (=PCD) of the joint.Type: ApplicationFiled: March 17, 2006Publication date: October 5, 2006Inventors: Junichi Izumino, Minoru Ishijima
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Publication number: 20060217205Abstract: A tripod constant velocity universal joint comprises among others an inner joint member having a boss 22 and journals 24 radially protruding from the boss, a radius of curvature R1 as viewed in a cross section of a journal bottom part 23 connecting the boss 22 to the journal 24 and as measured at locations opposing circumferentially of the joint is larger than a radius of curvature R2 of the journal bottom part as viewed in its cross section and as measured at locations opposing axially of the joint and R1 gradually decreases down to R2.Type: ApplicationFiled: March 9, 2006Publication date: September 28, 2006Inventors: Junichi Izumino, Minoru Ishijima
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Publication number: 20060040752Abstract: A constant velocity joint boot includes a first part attached to an outer joint member of a constant velocity joint, a second part attached to a shaft connected to an inner joint member, and abutment surfaces provided inside an operating part of the joint such that they make contact with each other when the shaft takes a predetermined operating angle.Type: ApplicationFiled: August 1, 2005Publication date: February 23, 2006Inventors: Minoru Ishijima, Kenta Yamazaki
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Publication number: 20060030413Abstract: The invention provides a tripod type constant velocity universal joint that can restrain generation of an excessive frictional force inside the joint because of the rotation phase angle of the inner joint member, thereby suppressing vibration and achieving higher rotation durability. The tripod type constant velocity universal joint includes an outer roller rotatably located inside the roller guide section of the outer joint member, and an inner roller spherically fitted to the trunnion of the inner joint member so as to be pivotally rotatable, and to support the outer roller permitting relative rotation and relative axial movement, so that when a torque is applied with the outer joint member and the inner joint member oriented with an operating angle ?, a facet of the outer roller inclined along with the rotation of the inner joint member is sustained by the track groove bottom portion formed in a flat plane.Type: ApplicationFiled: July 26, 2005Publication date: February 9, 2006Inventors: Junichi Izumino, Minoru Ishijima
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Publication number: 20050107168Abstract: A tripod type constant velocity universal joint that can suppress generation of shudder by reducing the 3rd order cyclic axial force and has high rotation durability. In a double-roller tripod type constant velocity universal joint, a track gap ?1 between one of the roller guiding surfaces formed on both sides of a track groove, which is on the no-load applied side, and an outer circumferential surface of an outer roller is set to satisfy ?1>0.03/A. Also, a shoulder gap ?2 between a guide shoulder surface formed at the bottom of the track groove and a side surface of the outer roller is set to satisfy ?2>0.15×A. In both the expressions, a degree of torus A is defined as a ratio of a radius of curvature r of a generatrix of the outer circumferential surface to a radius R of an outer circumference of the outer roller (A=r/R).Type: ApplicationFiled: November 4, 2004Publication date: May 19, 2005Inventors: Junichi Izumino, Minoru Ishijima, Kenta Yamazaki
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Publication number: 20040157667Abstract: A tripod type constant velocity joint comprising a hollow cylindrical housing fixed to the end of a first rotary shaft and formed at the inner peripheral surface thereof with axially extending recessed grooves opened at one axial end and located at circumferentially trisectional positions on the inner peripheral surface, a tripod consisting of a boss fixed to the end of a second rotary shaft, and end-spherical trunnion journals radially projecting from circumferentially trisectional positions on the boss, a roller assemblies each consisting of an inner roller swingably fitted at the inner peripheral surface thereof on the spherical outer peripheral surface of the trunnion journal, and an outer roller supported for rotation and axial movement on the outer peripheral surface of the inner roller through needle rollers, wherein the outer rollers are received in the recessed grooves in the housing and are rollable axially of the housing, each recessed groove consists of guide surfaces contacting the outer peripherType: ApplicationFiled: October 21, 2003Publication date: August 12, 2004Inventors: Minoru Ishijima, Kenta Yamazaki, Junichi Izumino
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Patent number: 6764406Abstract: A constant velocity joint of tripod type which is both highly strong and durable, and which can maintain a low axial force and low shudder when transmitting torque at a joint angle. The constant velocity joint of tripod type comprises a roller assembly including an outer roller, an inner roller and a needle bearing located therebetween. The outer roller is provided with needle bearing retaining rings and needle bearing stop rings, at each of its upper and lower ends, respectively. The inner roller moves relative to the outer roller in the axial direction. The outer face of the inner roller and the inner face of the outer roller have generally spherical shapes of dimensions similar to each other to freely engage, respectively. The outer face of the trunnion is provided with a partially cylindrical portion with inclined relative to a trunnion centerline.Type: GrantFiled: October 12, 2001Date of Patent: July 20, 2004Assignee: Delphi Technologies, Inc.Inventors: Yasumasa Mizukoshi, Minoru Ishijima, Toshihiro Ikeda