Patents by Inventor Takashi Tsujimoto
Takashi Tsujimoto 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).
-
Publication number: 20040047528Abstract: A tapered roller bearing and an automotive gear shaft support device can ensure a long endurance life even in the state in which debris is mixed. On the surfaces of an outer ring, inner ring, and tapered rollers formed from carburized bearing steel having an oxygen content of 9 ppm or less, carbo-nitrided layers having a carbon content of 0.80 wt % or over, a Rockwell hardness HRC of 58 or over, and a residual austenite content of 25-35 vol % are formed to increase mechanical properties and fatigue characteristics of the parts and to stably maintain the carbo-nitrided layers on the surfaces of the parts to a quality having suitable toughness, thereby markedly improving the endurance life of the tapered roller bearing in a state in which debris is mixed.Type: ApplicationFiled: August 28, 2003Publication date: March 11, 2004Inventors: Takashi Tsujimoto, Yuji Okamoto, Kikuo Maeda
-
Publication number: 20030185477Abstract: Fretting wear at the locations of contact between rolling elements and an inner ring is prevented even in the case where the outer ring and the inner ring of a roller bearing are rotating in synchronization. In a roller bearing oil feed device in which a plurality of rolling elements are arranged in a plurality of rows in the axial direction between this outer ring and inner ring, the inner ring being divided for each row of the rolling elements and a ring-shaped spacer being interposed at the position of this division, the inner rings and spacer being fitted onto a rotary shaft, a circumferential groove is provided in the inner peripheral section of the spacer and oil feed holes communicating with the circumferential groove are provided in the rotary shaft and an oil feed passage having an inlet opening into the circumferential groove and an outlet opening to a corner on at least one side in the axial direction of the spacer is provided in the spacer.Type: ApplicationFiled: March 26, 2003Publication date: October 2, 2003Applicants: Isuzu Motors Limited, NTN CorporationInventors: Masafumi Taki, Takashi Ito, Takashi Tsujimoto
-
Patent number: 6547443Abstract: A tapered roller bearing comprises inner and outer and outer rings having raceways, a large flange surface and a small flange surface, tapered rollers between the raceways and each having large and small end faces at the ends, and a retainer for the tapered rollers. The average roughness of the large end faces and the large flange surface is 0.14 &mgr;m Ra or less. The radius of curvature of the large end faces is 75 to 85% of the roller reference radius, and the central angle of the contact positions between the tapered rollers and the large flange surface is {fraction (1/15)} to {fraction (1/10)} of the roller angle. The center of the contact surface between the tapered rollers and the raceways is offset toward the large end faces from the center of the rolling surfaces of the tapered rollers by 10% or less of the effective length of the tapered rollers.Type: GrantFiled: October 16, 2001Date of Patent: April 15, 2003Assignee: NTN CorporationInventors: Kimihiro Hanai, Takashi Tsujimoto, Tsukasa Yamakawa, Yasuhiro Shimizu, Shiro Ishikawa
-
Publication number: 20020186908Abstract: A tapered roller bearing and an automotive gear shaft support device can ensure a long endurance life even in the state in which debris is mixed. On the surfaces of an outer ring, inner ring, and tapered rollers formed from carburized bearing steel having an oxygen content of 9 ppm or less, carbo-nitrided layers having a carbon content of 0.80 wt % or over, a Rockwell hardness HRC of 58 or over, and a residual austenite content of 25-35 vol % are formed to increase mechanical properties and fatigue characteristics of the parts and to stably maintain the carbo-nitrided layers on the surfaces of the parts to a quality having suitable toughness, thereby markedly improving the endurance life of the tapered roller bearing in a state in which debris is mixed.Type: ApplicationFiled: July 24, 2002Publication date: December 12, 2002Inventors: Takashi Tsujimoto, Yuji Okamoto, Kikuo Maeda
-
Patent number: 6447168Abstract: A tapered roller bearing and an automotive gear shaft support device can ensure a long endurance life even in the state in which debris is mixed. On the surfaces of an outer ring, inner ring, and tapered rollers formed from carburized bearing steel having an oxygen content of 9 ppm or less, carbo-nitrided layers having a carbon content of 0.80 wt % or over, a Rockwell hardness HRC of 58 or over, and a residual austenite content of 25-35 vol % are formed to increase mechanical properties and fatigue characteristics of the parts and to stably maintain the carbo-nitrided layers on the surfaces of the parts to a quality having suitable toughness, thereby markedly improving the endurance life of the tapered roller bearing in a state in which debris is mixed.Type: GrantFiled: June 22, 2001Date of Patent: September 10, 2002Assignee: NTN CorporationInventors: Takashi Tsujimoto, Yuji Okamoto, Kikuo Maeda
-
Publication number: 20020044707Abstract: A tapered roller bearing is proposed which comprises an inner ring having a raceway on its outer peripheral surface, an outer ring having a raceway on its inner peripheral surface, a large flange surface and a small flange surface, tapered rollers rollably mounted between the raceway of the inner ring and the raceway of the outer ring and having a large end face at one end thereof and a small end face at the other end thereof, and a retainer for retaining the tapered rollers at regular spacings, wherein the average roughness R[=(Rr2+Rb2){fraction (1/2)}] of the roughness Rr of the large end faces of the tapered rollers and the roughness Rb of the large flange surface of the inner ring is 0.Type: ApplicationFiled: October 16, 2001Publication date: April 18, 2002Inventors: Kimihiro Hanai, Takashi Tsujimoto, Tsukasa Yamakawa, Yasuhiro Shimizu, Shiro Ishikawa
-
Patent number: 6328477Abstract: A tapered roller bearing and an automotive gear shaft support device which can ensure a long endurance life even in the state in which debris is mixed. On the surfaces of an outer ring, inner ring, and tapered rollers formed from carburized bearing steel having an oxygen content of 9 ppm or less, carbo-nitrided layers having a carbon content of 0.80 wt % or over, a Rockwell hardness HRC of 58 or over, and a residual austenite content of 25-35 vol % are formed to increase mechanical properties and fatigue characteristics of the parts and to stably maintain the carbo-nitrided layers on the surfaces of the parts to a quality having suitable toughness, thereby markedly improving the endurance life of the tapered roller bearing in a state in which debris mixed.Type: GrantFiled: November 24, 1999Date of Patent: December 11, 2001Assignee: NTN CorporationInventors: Takashi Tsujimoto, Yuji Okamoto, Kikuo Maeda
-
Publication number: 20010031105Abstract: A tapered roller bearing and an automotive gear shaft support device can ensure a long endurance life even in the state in which debris is mixed. On the surfaces of an outer ring, inner ring, and tapered rollers formed from carburized bearing steel having an oxygen content of 9 ppm or less, carbo-nitrided layers having a carbon content of 0.80 wt % or over, a Rockwell hardness HRC of 58 or over, and a residual austenite content of 25-35 vol % are formed to increase mechanical properties and fatigue characteristics of the parts and to stably maintain the carbo-nitrided layers on the surfaces of the parts to a quality having suitable toughness, thereby markedly improving the endurance life of the tapered roller bearing in a state in which debris is mixed.Type: ApplicationFiled: June 22, 2001Publication date: October 18, 2001Inventors: Takashi Tsujimoto, Yuji Okamoto, Kikuo Maeda
-
Patent number: 6261004Abstract: An object is to exert the intended fretting-preventive effect without being influenced by the size of variation in rotation (variation in speed) or the size of vibration. An arrangement comprising a main shaft gear 1 having a raceway surface 1c on its inner peripheral surface, a bearing inner ring 2 having a raceway surface 2a on the outer periphery, tapered rollers 3 disposed between the raceway surface 1c of the main shaft gear 1 and the raceway surface 2a of the bearing inner ring 2 and held at predetermined circumferential intervals by a cage 4, an imbalance means which produces a circumferential weight imbalance in the assembly of the tapered rollers 3 and cage 4, wherein the roughness of the cone back face 2b of the bearing inner ring 2 is 0.01-0.04 &mgr;mRa, and the roughness of the large end faces 3b of the tapered rollers 3 is 0.01-0.Type: GrantFiled: December 13, 1999Date of Patent: July 17, 2001Assignee: NTN CorporationInventors: Takashi Tsujimoto, Mamoru Mizutani
-
Patent number: 6217225Abstract: A wheel support device which is easy to assemble and compact in size. A pair of tapered roller bearings are mounted on the outer periphery of an axle. The pair of tapered roller bearings rotatably support an axle hub that rotates together with a wheel. A seal assembly is mounted between the outer and inner rings of one of the tapered roller bearings. The seal assembly prevents leakage of grease sealed in the axle hub and entry of muddy water from outside, and makes it unnecessary to provide a separate seal member, thus making it possible to assemble the wheel support device easily and to reduce its size.Type: GrantFiled: May 27, 1999Date of Patent: April 17, 2001Assignee: NTN CorporationInventors: Yasuhiko Shimizu, Junichi Hattori, Hiroyuki Ichikawa, Takashi Tsujimoto
-
Patent number: 6086261Abstract: The raceway groove width (W) of the inner ring 2 and the length (L) of the tapered roller 3 are finished within predetermined dimensional tolerances. The retaining rib face 2b of the inner ring 2 is machined such that it is a surface parallel to the small end faces 3b of the tapered rollers 3. The clearances .delta. which are defined when the tapered rollers 3 are disposed on the raceway surface 2a of the inner ring 2 and are contacted at the large end faces 3a thereof with the cone back face rib face 2c is secured to be within the dimensional range, .delta..ltoreq.0.4 mm.Type: GrantFiled: January 11, 1999Date of Patent: July 11, 2000Assignee: NTN CorporationInventors: Kazufumi Nakagawa, Kazumi Adachi, Kazunori Urakami, Kouji Masuoka, Takashi Tsujimoto
-
Patent number: 5852947Abstract: A bearing unit A comprises a main shaft gear 1 integrally having a tooth section 1a always meshed with a sub shaft gear 6 at the outer circumference, a pair of inner rings 2 fitted in the outer circumference of the main shaft 5, double-row tapered rollers 3 disposed between the raceway surface of the main shaft gear 1 and that of the inner ring 2, and a pair of cages 4 for respectively retaining each row of tapered rollers 3. The pockets 4a of the cage 4 are unequally pitched, wherein the tapered rollers 3 housed in the pockets 4a are unequally disposed at the circumference.Type: GrantFiled: February 24, 1997Date of Patent: December 29, 1998Assignee: NTN CorporationInventors: Takashi Tsujimoto, Mamoru Mizutani
-
Patent number: 4757681Abstract: This invention relates to a chain link plate which is constructed by a high tensile strength fiber which is wound around between two pivot points and which is fixed to each other by adhesive material. The link plate is improved in strength and decreased in weight.Type: GrantFiled: June 18, 1987Date of Patent: July 19, 1988Assignee: Tsubakimoto Chain Co.Inventors: Kazumasa Matsuno, Takashi Tsujimoto, Takerou Nakagawa, Yasumasa Tubakimoto, Makoto Kanehira
-
Patent number: 4724669Abstract: A conveyor or chain having a tubular filament-wound cylindrical element used as the pins interconnecting the link plates and/or as rollers or bushings in the chain assembly. The element is formed from a length of tubular material which is wound on a mandrel having an outside diameter equal to the inside diameter of the tubular element. The filament of the winding is a long aramid fiber which is integrated in the tubular material by an adhesive agent.Type: GrantFiled: April 30, 1986Date of Patent: February 16, 1988Assignee: Tsubakimoto Chain Co.Inventors: Makoto Kanehira, Takashi Koizumi, Takerou Nakagawa, Kazumasa Matsuno, Yasumasa Tsubakimoto, Fumio Ochiai, Takashi Tsujimoto