Roller Bearing Element Patents (Class 148/906)
  • Patent number: 6409846
    Abstract: In a rolling bearing having a fixed race, a rotary race and a plurality of rolling elements disposed between said fixed race and said rotary race, at least said fixed race is made of a steel having 0.35 to 0.55% by weight of C, 11.0 to 17.0% by weight of Cr, 0.05 to less than 0.2% by weight of N and the rest of Fe and unavoidable components. Further, the sum of the content of C and N is from 0.45 to 0.65% by weight or less, and exhibits a surface hardness HRC of 57 or more after heat treatment and the diameter of eutectic carbide produced on said bearing races is 10 &mgr;m or less.
    Type: Grant
    Filed: March 17, 2000
    Date of Patent: June 25, 2002
    Assignee: NSK, Ltd.
    Inventors: Hiromichi Takemura, Susumu Tanaka, Shigeru Okita
  • Patent number: 6403026
    Abstract: Steel for the manufacture of a component for bearings, the chemical composition of which comprises, by weight: 0.6%≦C≦1.5%; 0.4%≦Mn≦1.5%; 0.75%≦Si≦2.5%, 0.2%≦Cr≦2%; 0%≦Ni≦0.5%; 0%≦Mo≦0.2%; 0%≦Al≦0.05%; S≦0.04%; the balance being iron and impurities resulting from smelting and the composition furthermore satisfying the relationships: Mn≦0.75+0.55×Si and Mn≦2.5−0.8×Si. Process for the manufacture of a bearing component.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: June 11, 2002
    Assignees: Ascometal, S.N.R. Roulements, Valti Societe Anonyme pour la Fabrication de Tubes Roulements
    Inventors: Jacques Bellus, Gilles Baudry, Gilles Dudragne, Daniel Girodin, Gérard Jacob, Alain Vincent, Gérard Lormand
  • Patent number: 6398886
    Abstract: A process of finishing outer joint parts formed in a non-cutting way and intended for constant velocity joints, said outer joint parts having a longitudinal axis and an inner recess which extends in the direction of the longitudinal axis and which, in the direction of the longitudinal axis, is substantially undercut-free, with the inner recess being provided with tracks which comprise contact zones for the rolling contact of rolling contact members, characterized by the following sequence of process stages: non-cutting forming of the outer joint part, surface-layer-hardening of the inner recess at least along the length of the contact zones, for the purpose of producing a hardened surface layer, at least in the region of the contact zones above an unhardened matrix, calibrating the contact zones in respect of their radial positions and axial linearity by displacing the hardened surface layer in the region of the contact zones within the unhardened matrix.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: June 4, 2002
    Assignee: GKN Automotive AG
    Inventors: Peter Fuhrmann, Hans-Willi Kinzel
  • Patent number: 6398420
    Abstract: The material of inner ring, outer ring and rolling element is formed by a steel material having a chromium (Cr) content of 5% by weight or more. The material is then subjected to cutting. Thereafter, the material thus cut is subjected to heat treatment so that the surface hardness HRC of the worked material is 58 or more. Subsequently, the worked material is subjected to grinding. A working denatured layer present on the surface of the worked material is then removed. Subsequently, an oxide film comprising chromium atom and iron atom at a ratio (Cr/Fe) of 0.5 or more is formed on the surface of the worked material. Accordingly, it is possible to provide a rolling bearing excellent in corrosion resistance and fretting resistance.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: June 4, 2002
    Assignee: NSK, Ltd.
    Inventors: Susumu Tanaka, Hiroyuki Ito
  • Patent number: 6383317
    Abstract: Steel for the manufacture of a component for bearings, the chemical composition of which comprises, by weight: 0.6%≦C≦1.5%; 0.4%≦Mn≦1.5%; 0.75%≦Si≦2.5%; 0.2%≦Cr≦2%; 0%≦Ni≦0.5%; 0%≦Mo≦0.2%; 0%<Al≦0.05%; S≦0.04%; the balance being iron and impurities resulting from smelting and the composition furthermore satisfying the relationships: Mn≦0.75+0.55×Si and Mn≦2.5−0.8×Si. Process for the manufacture of a bearing component.
    Type: Grant
    Filed: July 13, 2000
    Date of Patent: May 7, 2002
    Assignees: Ascometal, S.N.R. Roulements, Valti Societe Anonyme pour la Fabrication de Tubes Roulements
    Inventors: Jacques Bellus, Gilles Baudry, Gilles Dudragne, Daniel Girodin, Gérard Jacob, Alain Vincent, Gérard Lormand
  • Patent number: 6358333
    Abstract: An inexpensive rolling apparatus improved in resistance to fretting, acoustic performance, resistance to corrosion, life and workability is provided. At least one of an outer member, an inner member and rolling elements of the apparatus is formed of an alloy steel containing 1.5% by weight or less of C, 10% to 20% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si and less than 0.2% by weight of N, particularly, at least one of the outer member, the inner member and the rolling elements is formed of a martensitic stainless steel containing 0.6% by weight or less of C, 10% to 14% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si, less than 0.2% by weight of N, 0.5% by weight or less of Mo, 0.2% by weight or less of V, and Fe and inevitable components as the balance, wherein the relationship between the content of C and that of Cr satisfies C %≦−0.05 Cr %+1.
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: March 19, 2002
    Assignee: NSK Ltd.
    Inventors: Susumu Tanaka, Kenji Yamamura, Manabu Obori
  • Patent number: 6348114
    Abstract: A sliding bearing having improved seizure resistance has the following structure: (a) A bearing layer (2). It comprises a copper alloy containing in a Cu matrix Ag, Sn, Sb, In, Mn, Fe, Bi, Zn, Ni and/or Cr. (b) A first sub-layer (3) of the bearing layer (2). First sub-layer (3) contains concentrated element, hexagonal compound or eutectic of said element(s). (c) A second sub-layer (2a) in which said element in essential solid-solution state. (d) Metal backing (1).
    Type: Grant
    Filed: March 24, 1999
    Date of Patent: February 19, 2002
    Assignee: Taiho Kogyo Co., Ltd.
    Inventors: Haruyuki Oshiro, Takashi Tomikawa, Soji Kamiya, Katuyuki Hashizume
  • Patent number: 6337145
    Abstract: A process for the production of sliding elements in which an overlay of lead-tin-copper is applied by electroplating to the prefabricated semi-finished product, and in which a ternary, fluoroborate-free electroplating bath is used without brighteners and with the addition of non-ionic wetting agents and free alkyl sulfonic acid. After the deposition of the galvanic overlay a heat treatment is carried out in the temperature range of 150° C. to 200° C. for between 1 and 100 hours. The multilayer material for sliding elements comprises at least a backing and an overlay of 12 to 16 wt. % tin and 7 to 11 wt. % copper, the rest being lead. The overlay comprises 15 to 25 wt. % particles of intermetallic compound Cu6Sn5.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: January 8, 2002
    Assignee: Federal-Mogul Wiesbaden GmbH & Co.
    Inventor: George Pratt
  • Patent number: 6333001
    Abstract: A micro-alloyed steel for rolling bearings and especially for HBU/THU forgings with improved yield strength in “as forged condition. The steel has the following composition 0.5-0.7% C, 0-0.6% Si, 0.4-1.2% Mn, 0-0.035% S, 0.05-2.0% V, 80-160 ppm N, the remainder iron and ordinary impurities.
    Type: Grant
    Filed: April 29, 1998
    Date of Patent: December 25, 2001
    Assignee: Ovaka Steel
    Inventors: Rainer R. Leppänen, John Beswick
  • Patent number: 6325867
    Abstract: A rolling bearing contains no more than 0.3 wt % of nitrogen in a grinding allowance portion after carbonitriding and hardening heat treatments, contains from 0.9 wt % (inclusive) up to 1.6 wt % (inclusive) of carbon and from 0.05 wt % (inclusive) up to 0.3 wt % (inclusive) of nitrogen in the surface layer of the finished part and has a nitrogen gradient of no more than 0.5 wt %/mm in the surface layer of the finished part. The rolling bearings are improved in grinding efficiency and which have their rolling life extended significantly.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: December 4, 2001
    Assignee: NSK Ltd.
    Inventors: Shigeru Okita, Yasuo Utsumi, Akihiro Kiuchi
  • Patent number: 6315455
    Abstract: The rolling bearing according to the invention comprises a dense nitride layer formed on the surface layer of the rolling elements and optionally an optimum carbonitride layer formed on the races. In this arrangement, the deterioration of durability due to vibration or impact load during transportation can be prevented, not to mention improvement of stillness. Further, the deterioration of impact resistance required for hybrid bearing can be prevented. The release of pilot pressure and defective of acoustic properties due to electrostatic attraction of dust can be prevented. At the same time, the rolling element of the invention comprises a compound layer having an extremely high hardness formed uniformly, making it possible to finish to a high precision. Moreover, a great effect can be exerted of preventing the change of properties with time at high temperature or the deterioration of acoustic properties under other severe working conditions.
    Type: Grant
    Filed: April 3, 2000
    Date of Patent: November 13, 2001
    Assignee: NSK Ltd.
    Inventors: Susumu Tanaka, Manabu Ohori
  • Patent number: 6309475
    Abstract: For easily producing a toothed material for high-strength gears etc. with a plastic working technique, deformation resistance occurring in plastic working is reduced and stable high precision plastic working is enabled at lower temperatures. One or more types of heat treatment selected from carburization, carbonitriding and nitriding and a hardening process are applied to an alloy steel material containing: iron as a main component; at least 1.0 to 4.5 wt % Si; 0.35 wt % or less C; and balance Fe and unavoidable impurities, whereby a rolling element is obtained which has a surface layer mainly composed of martensite containing no &agr;-Fe phase and of residual austenite and an inner structure cooled from an (&agr;+&ggr;)-Fe two phase region.
    Type: Grant
    Filed: January 26, 1999
    Date of Patent: October 30, 2001
    Assignee: Komatsu Ltd.
    Inventors: Takemori Takayama, Chikara Nakao
  • Patent number: 6306230
    Abstract: A method for producing hardened parts of steel from an air-hardening steel comprising the steps of heating the steel is heated to a temperature above 1,100° C., hot-working the steel parts until they reach the A1 emperature, cooling the steel parts in air to about 280° C. under simultaneous thermo-mechanical sizing treatment, then cooling the steel parts in air to room temperature, stress relief treating the steel parts at 150-250° C., and hard-machining the steel parts.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: October 23, 2001
    Assignee: SKF GmbH
    Inventor: Frank Hengerer
  • Patent number: 6284062
    Abstract: A member used in contact with a hot dip galvanizing bath, such as a sinker roll, a support roll or a bearing, is produced by nitriding stainless steel to form a nitride layer and a nitrogen-diffused layer on the surface thereof. The member used in contact with a hot dip galvanizing bath is formed on its surface with the nitride layer by nitriding it in a salt bath containing a cyanide, a cyanate, a carbonate and the like or by heat-treating it in an atmosphere containing ammonium or nitrogen.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: September 4, 2001
    Assignee: Taiyo Steel Co., Ltd.
    Inventors: Takeo Nagashima, Eizo Sakuma, Katsuaki Takano
  • Patent number: 6280537
    Abstract: A rolling bearing composed of a combination of bearing wings formed with a steel material and rolling elements formed with a ceramic material, wherein the residual austenite amount of the steel material forming the rolling rings is controlled to a specific value. By the construction, at rolling of the rolling elements formed with a relatively hard ceramic material, the occurrence of the surface scratches of the rolling elements can be restrained, which results in restraining the vibrations and noises caused from the rolling bearing.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: August 28, 2001
    Assignee: Koyo Seiko Co., Ltd.
    Inventors: Kiyoshi Tanimoto, Shinji Abe
  • Patent number: 6251197
    Abstract: A rolling or sliding part is produced from a blank of steel material subjected to a heat treatment including carburization and thereby made to contain a spheroidal carbide precipitated and dispersed in a carburized layer matrix. The particle-to-particle distance of the spheroidal carbide is up to 15 &mgr;m in terms of the distance between the most proximate particles. The rolling or sliding part is suitable as antifriction bearing components, such bearing rings and rolling bodies, or as sliding bearing components, for use in soiled oil containing extraneous matter. The antifriction bearing comprising this part serves a lengthened rolling life in soiled oil and clean oil, and the sliding bearing incorporating the part is also given an extended life.
    Type: Grant
    Filed: October 28, 1999
    Date of Patent: June 26, 2001
    Assignee: Koyo Seiko Co., Ltd.
    Inventor: Kazutoshi Toda
  • Patent number: 6248186
    Abstract: A ball-and-roller bearing is disclosed having an inner ring, an outer ring arranged on the axis of the inner ring and rotating around the co-axis relative to the inner ring, and a rolling body interposed between the inner ring and the outer ring and rolling with rotation of the outer ring relative to the inner ring. One of the inner ring, the outer ring, and the rolling body has a core member made from an alloy containing iron, at least one of 0.2 to 1.0% by weight of silicon and 0.2 to 1.5% by weight of manganese, 7.0 to 11.0% by weight of chromium, 1.5 to 6.0% by weight of molybdenum, and 0.5 to 8.0% by weight of cobalt, and a case hardened surface layer. Also disclosed is the method of manufacturing the bearing by forming a core member of the alloy, forming a case hardened layer containing 0.9 to 1.
    Type: Grant
    Filed: July 2, 1999
    Date of Patent: June 19, 2001
    Assignee: NSK Ltd.
    Inventors: Kenji Yamamura, Susumu Tanaka, Manabu Ohori
  • Patent number: 6228184
    Abstract: An inexpensive rolling apparatus improved in resistance to fretting, acoustic performance, resistance to corrosion, life and workability is provided. At least one of an outer member, an inner member and rolling elements of the apparatus is formed of an alloy steel containing 1.5% by weight or less of C, 10% to 20% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si and less than 0.2% by weight of N, particularly, at least one of the outer member, the inner member and the rolling elements is formed of a martensitic stainless steel containing 0.6% by weight or less of C, 10% to 14% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si, less than 0.2% by weight of N, 0.5% by weight or less of Mo, 0.2% by weight or less of V, and Fe and inevitable components as the balance, wherein the relationship between the content of C and that of Cr satisfies C %≦−0.05 Cr %+1.
    Type: Grant
    Filed: May 24, 2000
    Date of Patent: May 8, 2001
    Assignee: NSK Ltd.
    Inventors: Susumu Tanaka, Kenji Yamamura, Manabu Obori
  • Patent number: 6224688
    Abstract: A rolling bearing having a plurality of rolling elements located between a fixed race and a rotating race, wherein at least one of bearing components comprising the fixed race, rotating race and rolling elements is made of a steel which contains from 0.05 to 0.40% by weight of at least one selected from the group consisting of Ti, Nb and Al along with from 0.65 to 1.20% by weight of C, from 0.05 to 0.70% by weight of Si, from 0.2 to 1.5% by weight of Mn, from 0.15 to 2.0% by weight of Cr, not more than 01.01% by weight of N and unavoidable contaminating elements and wherein particles of at least one of Ti carbide, Ti carbonitride, Nb carbide, Nb carbonitride and Al nitride are dispersed and deposited at least in the vicinity of the surface of the at Least one of bearing components.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: May 1, 2001
    Assignee: NSK Ltd.
    Inventors: Hiromichi Takemura, Yasuo Murakami
  • Patent number: 6197128
    Abstract: A rolling bearing including a rolling bearing ring and a rolling element, at least one of the rolling bearing ring and the rolling element consisting of carburized steel containing at least 0.3% and at most 0.6% of C, at least 0.1% and at most 0.35% of Si, at least 1.1% and at most 1.5% of Mn, at least 0.5% and at most 2.0% of Cr, at least 0.2% and at most 0.6% of Ni and at least 0.15% and at most 0.5% of Mo by weight. Thus, an inexpensive and long life carburized steel rolling bearing can be obtained using a combination of chemical components of a relatively low cost.
    Type: Grant
    Filed: September 21, 1998
    Date of Patent: March 6, 2001
    Assignee: NTN Corporation
    Inventor: Kikuo Maeda
  • Patent number: 6176948
    Abstract: A method for the manufacture of components made of steel subject to heavy stress, load and/or wear, such as rolling bearing elements, hot forming components of a steel having an austenite carbon content at a hot forming temperature of about 800-1100° C. of 0.55-0.85 wt %, above the Al temperature of the steel; hardening the components directly from the hot forming temperature in air; hard machining of the components to their final dimensions; and surface finishing the components.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: January 23, 2001
    Assignee: Ovako Steel AB
    Inventors: Thore Lund, Staffan Larsson, Patrik {umlaut over (O)}lund
  • Patent number: 6171411
    Abstract: Disclosed is a rolling bearing comprising an inner race, an outer race, and a plurality of rolling elements, at least one of the inner race and the outer race being formed of an alloy steel which comprises: 0.7≦C≦0.9% by weight; 0.1≦Si≦0.5% by weight; 0.5≦Mn≦1.1% by weight; and 0.1≦Cr≦0.6% by weight; and including, in its surface layer, at least one of 0.8≦C≦1.4% by weight and 0.01≦N≦0.3% by weight. The rolling bearing can be obtained at an extremely low cost and has a long life in a severe environment particularly under contaminated lubrication.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: January 9, 2001
    Assignee: NSK Ltd.
    Inventors: Shigeru Okita, Susumu Tanaka
  • Patent number: 6165289
    Abstract: A water-resistant and long-life rolling bearing used in an environment involving water's seeping in the lubricant thereof, wherein at least one of the inner race, the outer race, and the rolling member is formed of alloy steel containing 0.05 to 0.60% by weight of Cu, 0.10 to 1.10% by weight of C, and 0 to 0.2% by weight of Nb or V. The alloy steel has functions of reducing hydrogen evolution on the surface thereof and of forming a film hardly permeable to hydrogen thereby to retard occurrence of flaking due to hydrogen-induced brittleness.
    Type: Grant
    Filed: April 10, 1997
    Date of Patent: December 26, 2000
    Assignee: NSK Ltd.
    Inventors: Yoichi Matsumoto, Tomonobu Yoshikawa, Takashi Nagato
  • Patent number: 6162390
    Abstract: Steel for the manufacture of a component for bearings, the chemical composition of which comprises, by weight: 0.6%.ltoreq.C.ltoreq.1.5%; 0.4%.ltoreq.Mn.ltoreq.1.5%; 0.75%.ltoreq.Si.ltoreq.2.5%; 0.2%.ltoreq.Cr.ltoreq.2%; 0%.ltoreq.Ni.ltoreq.0.5%; 0%.ltoreq.Mo.ltoreq.0.2%; 0%<Al.ltoreq.0.05%; S.ltoreq.0.04%; the balance being iron and impurities resulting from smelting and the composition furthermore satisfying the relationships: Mn.ltoreq.0.75+0.55.times.Si and Mn.ltoreq.2.5-0.8.times.Si. Process for the manufacture of a bearing component.
    Type: Grant
    Filed: April 6, 1998
    Date of Patent: December 19, 2000
    Assignees: Ascometal, S.N.R. Roulements, Valti Societe Anonyme pour la Frabrication de tubes Roulements
    Inventors: Jacques Bellus, Gilles Baudry, Gilles Dudragne, Daniel Girodin, Gerard Jacob, Alain Vincent, Gerard Lormand
  • Patent number: 6158263
    Abstract: A roll supporting device for a rolling mill arrangement, supporting rolls rotatably to housings by double row roller bearings or multi-row roller bearings. On surfaces of bearing rings and rollers of the roller bearing are provided carbonitrided layers of 0.80% or greater in carbon content and of Rockwell hardness HRC 58 or greater. The carbonitrided layers are formed to contain residual austenite content of 25-30% by volume. By virtue of the carbonitrided layers, the strength against the surface-initiated type damage to the contact surfaces of the bearing rings and the rollers is improved, so that the enhancement of the life of the roll supporting device, especially the lives of the bearing portions thereof, can be achieved to contribute to the prolongation of inspection and maintenance periods and to the reduction of inspection and maintenance costs.
    Type: Grant
    Filed: June 18, 1999
    Date of Patent: December 12, 2000
    Assignee: NTN Corporation
    Inventors: Kikuo Maeda, Shinobu Nasu, Hideshi Nishiwaki
  • Patent number: 6149743
    Abstract: A method of complete bainite hardening of steel for use in bearings and other load carrying components, wherein bainite transformation is performed at a temperature just above the martensite formation temperature, transforming 25%-99% of the austenite into bainite at said temperature, and then increasing the temperature to speed up the transformation of the remaining austenite into bainite.
    Type: Grant
    Filed: July 21, 1998
    Date of Patent: November 21, 2000
    Assignee: Ovako Steel AB
    Inventors: Thore Lund, Staffan Larsson, Patrik Olund
  • Patent number: 6123785
    Abstract: The process for producing a constant velocity joint having improved cold workability, rolling fatigue life, and torsional strength comprises the steps of: rolling or forging an alloy at a heating temperature of Ac.sub.3 to 1000.degree. C. with a reduction in area of not less than 30%, said alloy comprising by weight carbon: 0.52 to 0.60%, silicon: 0.03 to 0.15%, manganese: 0.10 to 0.40%, chromium: 0.05 to 0.30%, molybdenum: 0.10 to 0.30%, sulfur: 0.003 to 0.020%, boron: 0.0005 to 0.005%, titanium: 0.02 to 0.05%, nitrogen: not more than 0.01%, aluminum: 0.005 to 0.05%, and manganese+chromium+molybdenum: 0.35 to 0.80% with the balance consisting of iron and unavoidable impurities; spheroidizing the rolled or forged alloy in such a manner that, after heating to Ac.sub.1 to 770.degree. C., slow cooling is performed from 730.degree. C. to 700.degree. C. at a rate of not more than 15.degree. C.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: September 26, 2000
    Assignees: Sanyo Special Steel Co., Ltd., Honda Motor Co., Ltd.
    Inventors: Makoto Iguchi, Motohiro Nishikawa, Masayoshi Saga
  • Patent number: 6119347
    Abstract: A method of manufacturing steel balls for use in a ball bearing comprising an inner steel race or shaft with an inner raceway formed around its outer peripheral surface, an outer steel race with an outer raceway formed around its inner peripheral surface, and the steel balls freely rotatably disposed between the inner raceway and the outer raceway comprises the steps of providing steel balls, quenching the steel balls, preliminarily tempering the steel balls after quenched, rough-polishing the steel balls after preliminarily tempered, surface-hardening the steel balls after rough-polished, tempering the steel balls after surface-hardened, and finish-polishing the steel balls after tempered.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: September 19, 2000
    Assignee: NSK, Ltd.
    Inventors: Kiyoshi Hirakawa, Akira Suzuki, Jiami Pu, Katsunori Yanase, Minoru Kohari, Eiichi Takahashi, Yasushi Mutch
  • Patent number: 6093268
    Abstract: In a corrective tempering method and apparatus for a rolling element in which the thermal deformation of the rolling element is corrected within an extremely short time by utilizing plasticity exhibited during a metallic structure transforming process brought about by low-temperature tempering of the rolling element made of steel, the hardened rolling element is heated and pressured to a maximum temperature within a range of from 250 to 500.degree. C. by a heating device while set in correcting molds to correct the deformation of the rolling element at a degree of working within a range not exceeding an elastic deformation range of the rolling element at a room temperature. The rolling element can be heated also by an induction heating device in addition to a conduction heating device. A product whose inner/outer diameter correcting degree of deformation is 60% or more, dimension standardizing rate is 30% or more, surface roughness is less than Ra 0.2 .mu.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: July 25, 2000
    Assignee: NSK Ltd.
    Inventors: Kiyoshi Hirakawa, Akitoshi Maeda, Hiroaki Sugiyama, Manabu Ohhori
  • Patent number: 6086686
    Abstract: An inexpensive rolling apparatus improved in resistance to fretting, acoustic performance, resistance to corrosion, life and workability is provided. At least one of an outer member, an inner member and rolling elements of the apparatus is formed of an alloy steel containing 1.5% by weight or less of C, 10% to 20% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si and less than 0.2% by weight of N, particularly, at least one of the outer member, the inner member and the rolling elements is formed of a martensitic stainless steel containing 0.6% by weight or less of C, 10% to 14% by weight of Cr, 0.1% to 0.8% by weight of Mn, 0.1% to 1.0% by weight of Si, less than 0.2% by weight of N, 0.5% by weight or less of Mo, 0.2% by weight or less of V, and Fe and inevitable components as the balance, wherein the relationship between the content of C and that of Cr satisfies C%.ltoreq.-0.05 Cr%+1.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: July 11, 2000
    Assignee: NSK Ltd.
    Inventors: Susumu Tanaka, Kenji Yamamura, Manabu Obori
  • Patent number: 6071358
    Abstract: At least one of the components of a rolling member used in a manner in which it is rolled or slid with a mated member is made of carbon steel containing 0.8%-0.9% by weight of C, 0.1%-0.7% by weight of Si, 0.5%-1.1% by weight of Mn, and 0.1%-0.6% by weight of Cr and Fe substantially in the remaining part, wherein an ideal critical diameter DI value calculated from the compositions is 1.5-4.0, and the retained austenite amount after hardened heat treatment is 8%-22% by volume. The value DI is determined by the following equation:DI=(0.311.times.C %.sup.0.498).times.(0.7.times.Si %+1).times.(3.33.times.Mn %+1).times.(2.16.times.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: June 6, 2000
    Assignee: NSK Ltd.
    Inventors: Shigeru Okita, Susumu Tanaka, Manabu Ohori, Koji Ueda, Akihiro Kiuchi
  • Patent number: 6063218
    Abstract: In a method of manufacturing a bearing, a high-frequency hardened steel essentially containing the following elements in the following percentage by weight is employed as the material of at least one of the outer and inner races of the bearing which is drilled,C; 0.5 to 0.65%, Si; 0.07 to 0.15%,Mn; 0.05 to 0.35%, Cr; 0.25 to 0.55%, andB; 0.0035% or less,a workpiece 10 Hv 230 in maximum hardness is formed with the high-frequency hardened steel subjected to hot forging, a part of the workpiece where a hole 12 is to be formed is drilled, and a part of the workpiece 10 where a track 14 is formed is subjected to high-frequency hardening until it becomes at least Hv 653 in hardness. The workpiece formed with the steel material subjected to hot forging is not larger than Hv 230 in maximum hardness. Hence, the workpiece can be drilled without reduction of the service life of the drilling tool, and the track region of the bearing has a hardness value which is practical in use.
    Type: Grant
    Filed: August 10, 1993
    Date of Patent: May 16, 2000
    Assignee: NSK Ltd.
    Inventors: Tomoki Muraoka, Masayuki Kobayashi
  • Patent number: 6051080
    Abstract: The invention relates to a power roller used for a toroidal-type continuously variable transmission. This power roller has on its first side a groove for receiving a bearing, and the surface of the groove (bearing surface) has a carbon concentration which is not lower than that of the back surface of a second side opposed to the first side. The power roller has a hardened outer layer having first and second portions which are respectively defined by the bearing surface and the back surface. The first portion of the hardened outer layer has an effective depth which is not shallower than that of the second portion thereof. The power roller is prepared by the sequential steps of surface-hardening, quenching, and grinding. The surface-hardening process is one of carburizing and carbonitriding.
    Type: Grant
    Filed: December 19, 1997
    Date of Patent: April 18, 2000
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Nobuo Kino, Toshifumi Hibi
  • Patent number: 6051082
    Abstract: A rolling bearing includes a rolling element made of a steel containing 0.9 to 1.1 wt. % C, 0.1 to 0.5 wt. % Si, 0.2 to 0.8 wt. % Mn, 1.0 to 1.8 wt. % Cr, with the balance being Fe and inevitable impurities. In the rolling bearing at least the surface of the rolling element includes carbides having an area fraction of 5% to 15%; of these carbides, carbides having an averaged particle diameter of 0.5 .mu.m or more share 50% or more of the area fraction of all the carbides; and of the carbides, carbides having an averaged particle diameter of 1 .mu.m or more share 2% or less of the area fraction of all the carbides; and wherein the rolling element has at least a Vickers surface hardness HV of 750 to 900.
    Type: Grant
    Filed: January 20, 1998
    Date of Patent: April 18, 2000
    Assignee: NSK Ltd.
    Inventors: Shigeru Okita, Manabu Ohori, Satoshi Kadokawa, Akihiro Kiuchi, Akira Iida
  • Patent number: 6048414
    Abstract: The present invention is directed to rolling type bearings having an enhanced resistance to acoustic performance degradation that are best suited for incorporation into information systems as well as methods of producing such rolling type bearings. The resistance to acoustic performance degradation is achieved by improving the microstructure of bearing steel to make it possible to prevent the formation of indentations which can result from prolonged exposure to high-temperature conditions, dropping or other impact loads. A rolling type bearing of the invention comprises outer and inner rings and rolling elements disposed therebetween, at least the outer and inner rings being made of a steel material whose microstructure consists essentially of a mixture of ferrite and cementite.
    Type: Grant
    Filed: July 18, 1997
    Date of Patent: April 11, 2000
    Assignee: NTN Corporation
    Inventors: Noriyuki Tsushima, Yasuhiro Yamamoto
  • Patent number: 5997661
    Abstract: A rotating shaft 4 is attached to an inner race 1, and an outer race 2 is fixed to a housing 5 so that the bearing is operated by the rotation of the rotating shaft 4. In this case, the inner race 1 is made to be the race on the rotating side, and the outer race 2 is made to be the race on the non-rotating side. The raw material composing the inner race 1, outer race 2 and rollers 3 is manufactured from alloy steel containing 4.5 weight % or less of Ni, and 0.5 weight % or less of Cu, and the average value of the Cu equivalent of the rollers 3 and the inner race 1 is set at a value higher than the Cu equivalent of the outer race 2. Thus, even in humid environments where water infiltrates into the lubricant, it is possible to make the rolling bearing have the same durable life as with rolling bearings which are used in normal environments.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: December 7, 1999
    Assignee: NSK Ltd.
    Inventors: Yoichi Matsumoto, Takashi Nagato, Kazuo Sekino
  • Patent number: 5989694
    Abstract: Disclosed is a rolling bearing comprising races and rolling elements, in which at least one of the races and the rolling elements has at least one of a carbide and a carbonitride precipitated in a surface layer thereof, inclusive of a cutting allowance, wherein the finished surface of at least one of the races and the rolling elements has a hardness of Hv600 to Hv700 at 300.degree. C. The rolling bearing has reliable wear resistance under severe conditions and thereby having an extended bearing life.
    Type: Grant
    Filed: June 17, 1997
    Date of Patent: November 23, 1999
    Assignee: NSK, Ltd.
    Inventors: Nobuaki Mitamura, Kazuo Sekino, Yasuo Murakami
  • Patent number: 5954894
    Abstract: A bearing steel part for a rolling bearing having a core portion and a high hardness region formed by carburization to cover the core portion is provided in which the composition of at least the core portion contains at least 0.15 wt. % and at most 0.20 wt. % of C, at least 4 wt. % and at most 7 wt. % of Cr, at least 1 wt. % and at most 3 wt. % of Mo, and at least 0.4 wt. % and at most O.9 wt. % of V, with Fe group as base material. Therefore, the bearing steel part for the rolling bearing can be obtained having a better rolling contact fatigue life realized by increasing the core hardness of carburized steel and also having a high fracture toughness value.
    Type: Grant
    Filed: September 23, 1997
    Date of Patent: September 21, 1999
    Assignee: NTN Corporation
    Inventor: Noriyuki Tsushima
  • Patent number: 5878496
    Abstract: A process for manufacturing a component on which in-service stresses are imposed by in-service loading conditions. The process generally entails fabricating the component such that residual stresses are induced in the component that substantially offset one or more primary stresses which would otherwise limit the maximum service life of the component. The residual stresses are induced by creating compressive stresses in the component that extend sufficiently beneath the working surface of the component during fabrication. In order to appropriately attain the necessary residual stresses, the process of this invention includes developing a model of the component, and then applying the in-service loading conditions to the model to determine the in-service stresses on the component. Thereafter, at least one of the in-service stresses is identified as being critical, i.e., a stress that establishes the maximum service life of the component.
    Type: Grant
    Filed: April 9, 1996
    Date of Patent: March 9, 1999
    Assignee: Purdue Research Foundation
    Inventors: Chunghorng R. Liu, Shridhar Mittal
  • Patent number: 5873956
    Abstract: In order to provide rolling bearings of high performance using case hardened stainless steels that are superior to the conventional martensite base stainless steels in terms of corrosion resistance, rolling fatigue strength and wear resistance and which also have high core toughness, at least one member of the rolling bearing selected from among the inner race, the outer race and the rolling elements is made of an alloy steel consisting essentially of less than 0.5 wt % C, 8.0 to 20.0 wt % Cr, 0.1 to 1.5 wt % Mn, 0.1 to 2.0 wt % Si and the balance of Fe and incidental impurity elements; the relationship between the C and Cr contents satisfies 0.04 Cr (wt %)-0.39.ltoreq.C (wt %).ltoreq.-0.05 Cr (wt %)+1.41; the bearing also has a surface layer that is formed by nitriding or carbonitriding at a temperature below Ac.sub.1, subsequent heating at a temperature of 900.degree. to 1,200.degree. C., hardening, a subzero treatment and tempering.
    Type: Grant
    Filed: February 21, 1997
    Date of Patent: February 23, 1999
    Assignee: NSK Ltd.
    Inventors: Susumu Tanaka, Kenji Yamamura, Manabu Ohori
  • Patent number: 5853660
    Abstract: A bearing steel includes 0.70 to 0.93 wt % of C, 0.15 to 0.50 wt % of Si, 0.50 to 1.10 wt % of Mn and 0.3 to 0.65 wt % of Cr, with the balance being Fe and incidental impurities, and it has the ratio Cr/C specified to fall within 0.4 to 0.7. Because of these compositional features, the generation of macro carbides is prevented and the need to perform soaking at high temperature for a prolonged time is eliminated. Further, the bearing steel saves the materials cost and the overall cost of heat treatments in the manufacture of bearings and which yet is capable of satisfying the requirements of various characteristics of bearings, as well as a rolling bearing that employs the bearing steel.
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: December 29, 1998
    Assignee: NSK Ltd.
    Inventors: Yasuo Murakami, Nobuaki Mitamura, Seiji Sato
  • Patent number: 5851313
    Abstract: A stainless steel bearing component containing in excess of 11% chromium and between 0.05% and 0.50% carbon is case-hardened by introducing carbon or nitrogen into the surface of the race using a plasma process. The component is heated in a chamber from which air is evacuated. There it is bombarded with hydrogen ions to clean its surface. Next, while the component remains at an elevated temperature, a gas containing carbon or nitrogen or both is introduced into the chamber where it exists at a relatively low pressure on the order of 2-9 torr. A plasma is produced intermittently, and it causes carbon or nitrogen or both to diffuse intio the surface of the component and create a case containing a greater proportion of carbon or nitrogen than the underlying core. Thereafter, the component is cooled and with most stainless steels this may be acheived by quenching in oil.
    Type: Grant
    Filed: September 18, 1996
    Date of Patent: December 22, 1998
    Assignee: The Timken Company
    Inventor: David L. Milam
  • Patent number: 5843369
    Abstract: To provide a stainless steel for anti-friction bearings, which is obtained by making its eutectic carbide contents finer in particle diameter and suppressing the generation of non-metallic substances to an extremely low level, thus having a homogenious and dense structure and permitting highly accurate machining. The provided stainless steel is composed of 0.60 to 0.75% of carbon, 10.5 to 13.5% of chromium, 1.0% or below of silicon and 0.3 to 0.8% of manganese, % being by weight, the remainder of the composition being iron and inevitably introduced impurities, has a hardness of HRC 58 or above, contains eutectic carbide particles of 10 .mu.m and below in diameter, and has oxygen and titanium concentrations each of 10 ppm or below.
    Type: Grant
    Filed: December 19, 1996
    Date of Patent: December 1, 1998
    Assignee: Minebea Kabushiki-Kaisha
    Inventors: Rikuro Obara, Yutaka Daikuhara
  • Patent number: 5788923
    Abstract: A bearing steel is provided which can satisfy bearing property requirements and, at the same time, is improved in mechanical properties, such as impact, crushing, and transverse properties, while reducing the cost of materials and the cost of heat treatment for the production of a bearing. The bearing steel comprises by weight C: 0.70 to 0.93%, Si: 0.15 to 0.50%, Mn: 0.50 to 1.10%, Cr: 0.30 to 0.65%, and N: 0.005 to 0.02% with the balance consisting of Fe and unavoidable impurities and 0.4.ltoreq.Cr/C.ltoreq.0.7, the steel further comprising at least one of (1) Al: 0.01 to 0.1% with Al.times.N.gtoreq.0.00015 and (2) Nb: 0.02 to 0.1%. A rolling bearing produced from the bearing steel is also provided.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: August 4, 1998
    Assignees: Sanyo Special Steel Co., Ltd., NSK Ltd.
    Inventors: Ryoji Hayashi, Kaneaki Hamada, Yasuo Murakami
  • Patent number: 5733388
    Abstract: Bearing steel materials that are superior in cold workability, machinability, hardenability and rolling contact fatigue life are provided. During the processing of steel materials, the generation of large carbides, that detrimentally affect the rolling contact fatigue life of the steel, is inhibited, thereby obviating the necessity of a heat treatment for dissolving the carbides. The present steel material contains the following alloy elements in percentage by mass: 0.55% to 0.82% of carbon; 0.05% to 0.20% of silicon; 0.50% or less of manganese; 0.90% to 1.30% of chromium; 0.05% to 0.30% of molybdenum; and the remaining percentage substantially of iron. After the spheroidizing annealing of the steel material, the total cross-sectional area rate of carbide is 25% or less.
    Type: Grant
    Filed: March 25, 1996
    Date of Patent: March 31, 1998
    Assignees: Daido Tokiushuko Kabushiki Kaisha, Koyo Seiko Co., Ltd.
    Inventors: Yutaka Kurebayashi, Sadayuki Nakamura, Masao Goto, Atsuhiko Ohta
  • Patent number: 5727317
    Abstract: An outer ring of an axle bearing is heat-treated and a through hole can be formed quickly and reliably. The outer ring has raceways on its inner periphery along which rolling elements roll. A through hole for mounting an antilock brake sensor is formed in the outer ring to extend from its outer periphery to the inner periphery. A plug is inserted into the hole thus formed. After hardening the raceways, the plug is pulled out of the hole. Since the hole is formed before hardening the raceways, it can be formed easily by drilling with an ordinary carbon steel tool. Since the raceways are hardened after inserting the rod-shaped metal plug into the hole 9, the heat produced during hardening will disperse through the plug. It is thus possible to prevent shoulder portions of the raceways from melting due to overheating.
    Type: Grant
    Filed: March 20, 1996
    Date of Patent: March 17, 1998
    Assignee: NTN Corporation
    Inventors: Itsuro Bekku, Eiji Tajima
  • Patent number: 5725690
    Abstract: This invention aims at providing a induction hardened bearing steel which can produce bearing parts at a low cost and can provide excellent rolling fatigue characteristics, the present invention provides a long life high-frequency-hardened bearing steel comprising, in terms of percent by weight, 0.45 to 0.7% of C, 0.05 to 1.7% of Si, 0.35 to 2.0% of Mn, 0.001 to 0.03% of S, 0.01 to 0.07% of Al 0.003 to 0.015% of N, 0.0005 to 0.03% of T.Mg, 0.005 to 1.2% of Mo, a specific amount of at least one member selected from the group consisting of Cr, Ni, V, Nb and B, and more than 0.025% of P, and not more than 0.004% of Ti and not more than 0.002% of T.O, wherein a number ratio of Mg type oxides contained in the steel is at least 0.8.
    Type: Grant
    Filed: July 18, 1996
    Date of Patent: March 10, 1998
    Assignee: Nippon Steel Corporation
    Inventors: Tatsuro Ochi, Yuji Kawauchi
  • Patent number: 5725688
    Abstract: At least one of surfaces including the raceway of an inner ring, the raceway of an outer ring, and at least the rolling surfaces of rolling elements is made of a steel containing nitrogen within the range of from 0.2 to 5.0 wt. % and chromium within the range of from 7.0 to 25 wt. %.
    Type: Grant
    Filed: February 25, 1997
    Date of Patent: March 10, 1998
    Assignee: NSK Ltd.
    Inventors: Hiromi Sugi, Takashi Nagato, Kenji Yamamura
  • Patent number: 5714015
    Abstract: A nitrocarburization treatment for steel components, such as steel balls or ball bearings is disclosed. In the process, the balls are treated in a nitrocarburizing environment and then reoriented, either inside or outside of that environment to form an epsilon iron nitride layer having some thickness over the entire surface of the ball and no bare spots. The reorientation process minimizes superficial metal flow at the surface of the balls and achieves consistent corrosion resistance of at least 96 hours in salt fog tests. Further, components that are cooled in a non-oxidizing environment and then reoriented prior to being returned to the nitrocarburizing environment develop a greater porous layer depth, which provides excellent oil retention for tribological applications.
    Type: Grant
    Filed: April 22, 1996
    Date of Patent: February 3, 1998
    Assignee: Frantz Manufacturing
    Inventor: Paul Lentz
  • Patent number: 5711914
    Abstract: The properties of conventional steels for rails, check rails and railroad rolling components can be improved by small amounts of tellurium. This applies particularly to the wear resistance and the mechanical properties in the transverse direction and at oxygen contents of less than 0.0015% and sulfur contents up to 0.007%.
    Type: Grant
    Filed: November 18, 1994
    Date of Patent: January 27, 1998
    Assignee: NMH Stahwerke GmbH
    Inventor: Wilhelm Heller