Gear, Threaded Article, Drill Or Serrated Work Surface (e.g., Saw Blade, Etc.) Patents (Class 148/573)
  • Patent number: 11317481
    Abstract: Provided is a supporting structure for an induction heating coil and an induction heating device in which a surface of an induction heating coil is not formed of a coating film for insulation that generates a gas, and movement of the induction heating coil when the induction heating coil is energized can be suppressed. A supporting structure 4 of an induction heating device 1 includes a supporting column 20 and a plurality of restricting members 21. The supporting column 20 is disposed at an outer side in a radial direction of winding portions 13 of the induction heating coil 3, and extends in an axial direction S1. The restricting members 21 receive the induction heating coil 3 to restrict movement of the induction heating coil 3 in the axial direction S1 in an insulated state, and are supported by the supporting column 20.
    Type: Grant
    Filed: November 29, 2017
    Date of Patent: April 26, 2022
    Assignee: Koyo Thermo Systems Co., Ltd.
    Inventor: Ryosuke Yamamoto
  • Patent number: 11090742
    Abstract: The invention relates to a method for machining a rack and to a rack (1) machined according to said method, for example a steering rack. In said method, the stress pattern that is present after hardening and/or straightening the rack and that has a chaotic internal stress distribution of tensile and compressive stresses is converted into a stress pattern that optimizes the strength and the use of the material and also the diameter of the rack, such that, without altering the structure, at least the region of the gear teeth (2) is pre-stressed, in a functionally combined series of steps of a machining pass, with a deliberately introduced internal compressive stress without tensile stress and with a predominantly uniform stress distribution or stress plane.
    Type: Grant
    Filed: September 23, 2017
    Date of Patent: August 17, 2021
    Assignee: MVO GMBH METALLVERARBEITUNG OSTALB
    Inventor: Niels Vieweg
  • Patent number: 10876191
    Abstract: The present disclosure relates to an induction annealing apparatus adapted to anneal cartridge cases to improve their reusability. In one implementation, the apparatus includes a power supply unit and a plurality of annealing units, each including a magnetic core having ends separated by an air gap. An induction coil is wound around the magnetic core to generate a magnetic field in the air gap. A cartridge case holder holds the cartridge case such that the neck of the cartridge case is positioned in one of the air gaps. The power supply unit selectively connects to the annealing units to supply power for a predetermined length of time, and the size of the air gap of the magnetic cores of each of the annealing units may differ. In other implementations, the size of the air gap may be adjustable, and a temperature sensor or a ferrite stake may be included.
    Type: Grant
    Filed: March 24, 2017
    Date of Patent: December 29, 2020
    Assignee: AMP Annealing Limited
    Inventors: Alexander Findlay, Matthew A. Findlay
  • Patent number: 10662993
    Abstract: A high-strength screw (1) includes a head (2) and a threaded portion (5) including a thread (6) and a thread end (9) facing away from the head (2) in an axial direction. The threaded portion (5) includes an unhardened portion (12) starting at the thread end (9) and extending in an axial direction. The unhardened portion (12) has a hardness being reduced compared to an axial middle portion (11) of the threaded portion (5).
    Type: Grant
    Filed: February 1, 2018
    Date of Patent: May 26, 2020
    Assignee: KAMAX HOLDING GMBH & CO. KG
    Inventors: Frank Wagner, Harald Frischkorn
  • Patent number: 10179940
    Abstract: A method and apparatus are present for manufacturing a part. The part is comprised of a metal alloy and is positioned to form a positioned part. An electromagnetic field is generated that heats the positioned part. A surface of the positioned part is exposed to an inert gas, while the electromagnetic field is generated to create an inverse thermal gradient between an exterior of the positioned part and an interior section of the positioned part to form a heat treated part.
    Type: Grant
    Filed: November 16, 2015
    Date of Patent: January 15, 2019
    Assignee: The Boeing Company
    Inventors: Brad L. Kirkwood, Marc R. Matsen, Tony Shen, Wesley B. Crow
  • Patent number: 9790583
    Abstract: A method and apparatus for manufacturing a part. The part may be positioned in a chamber. The part may be comprised of a metal and may be a positioned part. A gas containing nitrogen may be sent into the chamber. An electromagnetic field may be generated in the chamber with the gas. The electromagnetic field may heat a portion of the metal in the positioned part to a temperature from about 60 percent to about 99 percent of the melting point of the metal such that the portion of the metal has a desired hardness. The portion of the metal may extend from a surface of the positioned part to a selected depth from the surface.
    Type: Grant
    Filed: July 8, 2013
    Date of Patent: October 17, 2017
    Assignee: THE BOEING COMPANY
    Inventors: Dale J. Weires, Scott M. Holder, Julia H. Grogan
  • Patent number: 9693397
    Abstract: Apparatus is provided for inductively heat treating a circular surface of annular workpieces where at least one inductor pair is used to perform a scan induction heat treatment of the circular surface. Controlled movement of the inductors and application of quenchant is provided particularly at the initial and final heat treatment locations on the circular surface to enhance metallurgical uniformity of the annular workpiece at these locations. In combination with controlled movement of the inductors, a simultaneous power-frequency control scheme can be applied to the inductors during the heat treatment process with the apparatus.
    Type: Grant
    Filed: July 13, 2015
    Date of Patent: June 27, 2017
    Assignee: INDUCTOHEAT, INC.
    Inventors: Gary A. Doyon, Frank Andrä, Douglas R. Brown, Don L. Loveless, Valery I. Rudnev
  • Patent number: 9328811
    Abstract: A drive plate includes a disk-shaped plate portion; and a tooth-shaped portion formed at an outer peripheral end of the plate portion. The plate portion and the tooth-shaped portion are integrally shaped from a single steel plate material. The plate portion and the tooth-shaped portion include a carburized layer provided over an entire surface layer of the plate portion and the tooth-shaped portion, the carburized layer having a carbon concentration higher than that of a center portion of the plate portion and the tooth-shaped portion in a thickness direction. The carburized layer of the plate portion is higher in hardness than the center portion of the plate portion in the thickness direction. The carburized layer of the tooth-shaped portion has been subjected to a quenching process, and is further higher in hardness than the carburized layer of the plate portion.
    Type: Grant
    Filed: April 16, 2012
    Date of Patent: May 3, 2016
    Assignee: AISIN AW CO., LTD.
    Inventors: Daisuke Iwata, Tomoyuki Hori, Naoki Yokoyama, Koji Obayashi, Keita Taguchi, Hiroshi Shibata
  • Patent number: 9084297
    Abstract: Apparatus and method are provided for inductively heat treating a circular surface of annular workpieces where at least one inductor pair is used to perform a scan induction heat treatment of the circular surface. Controlled movement of the inductors and application of quenchant is provided particularly at the initial and final heat treatment locations on the circular surface to enhance metallurgical uniformity of the annular workpiece at these locations. In combination with controlled movement of the inductors, a simultaneous power-frequency control scheme can be applied to the inductors during the heat treatment process.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: July 14, 2015
    Assignee: INDUCTOHEAT, INC.
    Inventors: Gary A. Doyon, Frank Andrä, Douglas R. Brown, Don L. Loveless, Valery I. Rudnev
  • Patent number: 8829399
    Abstract: A method and device for heating or hardening at least an axial segment of a rotationally-symmetric surface of a work piece includes rotating the work piece about its rotational axis and moving a peripheral portion of an inductor along a longitudinal profile of the axial segment of the rotating work piece with a constant spacing between the peripheral portion and the axial segment. At least a portion of the movement of the peripheral portion is composed of a first vector component in the direction of the rotational axis and a second component extending perpendicularly to the first vector component. The peripheral portion has a length in the rotational axis direction that is less the length of the axial segment in the rotational axis direction.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: September 9, 2014
    Assignee: Aktiebolaget SKF
    Inventors: Marco Burtchen, Michael Jung
  • Publication number: 20130327451
    Abstract: A method for heat treating a gear having gear teeth includes removably mounting the gear on a work-piece holder, moving one of either a magnet assembly or the work-piece holder to bring the gear and the magnet assembly into heating proximity, rotating the magnet assembly for a desired amount of time while said magnet assembly and gear are in heating proximity to each other to heat treat surfaces of the gear teeth, moving one of either the magnet assembly or the work-piece holder relative to the other to bring different surfaces of the gear into heating proximity with said magnet assembly, and repeating for each opposed pair of gear teeth surfaces until all said gear teeth surfaces are heat treated.
    Type: Application
    Filed: August 12, 2013
    Publication date: December 12, 2013
    Applicant: The Timken Company
    Inventors: Stephen Johnson, Xiaolan Ai, Stephen B. Fitch
  • Patent number: 8529711
    Abstract: An induction heat treatment method with which temperature control is enabled, condition setting is easy, and the quality of a treatment object can be stabilized includes: a data acquiring step of heating and quench-hardening a sample of the treatment object to thereby acquire process data; a storing step of storing the process data; a checking step of checking the power supply output transition data and the quenching timing data as to validity based on the temperature transition data stored in the storing step; and a mass production step of performing heat treatment of the treatment object in accordance with the power supply output transition data and the quenching timing data stored in the storing step and checked as to validity in the checking step.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: September 10, 2013
    Assignee: NTN Corporation
    Inventors: Takumi Fujita, Nobuyuki Suzuki
  • Patent number: 8475610
    Abstract: A system and method of induction heat treating a gear includes a workstation. The workstation has a power source, an inductor coil, and a rotational mechanism. The gear is induction heat treated at a first portion of the gear and a second portion of the gear remains untreated by induction hardening. The gear has an inner surface. The inner surface includes the first portion and the second portion. The first portion has a first width. The second portion has a second width. The inductor coil includes at least one heating loop and at least one non-heating loop. The inductor coil is energized to a predetermined frequency to create an alternating magnetic field, where the alternating magnetic field developed in the heating loop induces an eddy current in the first portion of the gear.
    Type: Grant
    Filed: October 5, 2010
    Date of Patent: July 2, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Madhu Sudan Chatterjee, William Irwin Stuehr
  • Patent number: 8091239
    Abstract: A method is provided for producing a bearing ring (1) for large-size rolling bearings including at least one track (3) that is provided with a hardened peripheral layer. With the method the peripheral layer that is to be hardened is exposed to the electric field of an inductor in order to be heated and is then quenched. At least two inductors (2) are disposed above a common zone (a) of the annular track (3) that is to be hardened at the beginning of the hardening process. These inductors (2) heat the opposite peripheral layer to a hardening temperature at this location. The inductors (2) are moved in the opposite direction along the annular track in order to heat the adjacent central zones (b). Sprinklers (5) that are directed onto the heated peripheral layers are turned on following a short distance, and the peripheral layers are quenched starting from the center of the zone (a) that was heated at the beginning.
    Type: Grant
    Filed: February 11, 2006
    Date of Patent: January 10, 2012
    Assignees: Rothe Erde GmbH, EFD Induction GmbH
    Inventors: Joerg Rollmann, Wilfried Spintig, Bernd Stakemeier, Kristian Berggren
  • Publication number: 20110247732
    Abstract: A system and method of induction heat treating a gear includes a workstation. The workstation has a power source, an inductor coil, and a rotational mechanism. The gear is induction heat treated at a first portion of the gear and a second portion of the gear remains untreated by induction hardening. The gear has an inner surface. The inner surface includes the first portion and the second portion. The first portion has a first width. The second portion has a second width. The inductor coil includes at least one heating loop and at least one non-heating loop. The inductor coil is energized to a predetermined frequency to create an alternating magnetic field, where the alternating magnetic field developed in the heating loop induces an eddy current in the first portion of the gear.
    Type: Application
    Filed: October 5, 2010
    Publication date: October 13, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Madu Sudan Chatterjee, William Irwin Stuehr
  • Patent number: 7721617
    Abstract: A method of heat-treating a rack bar includes a step of continuously conveying a rack bar provided with a rack teeth portion and a ball screw portion by a quenching means, and a step of sequentially applying a quenching treatment to each circumferential surface of the rack teeth portion and the ball screw portion. The quenching treatment is preferably and sequentially applied to each entire circumferential surface of the rack teeth portion and the ball screw portion.
    Type: Grant
    Filed: June 6, 2003
    Date of Patent: May 25, 2010
    Assignee: JTEKT Corporation
    Inventor: Kenichi Fukumura
  • Patent number: 7691213
    Abstract: There is provided an inexpensive rolling element used under high interface pressure such as induction hardened gears, the rolling element being improved in the seizure resistance of its tooth flanks and having a temper hardness of HRC 50 or more at 300° C. To this end, the rolling element is made from a steel material containing at least 0.45 to 1.5 wt % C and one or more alloy elements selected from 0.1 to 0.5 wt % V and 0.3 to 1.5 wt % Cr, and has a rolling contact surface layer having a structure tempered at low temperature in which 2 to 18% by volume cementite disperses in a martensite parent phase formed by induction heating and cooling and containing 0.25 to 0.8 wt % carbon solid-dissolving therein.
    Type: Grant
    Filed: March 1, 2004
    Date of Patent: April 6, 2010
    Assignee: Komatsu Ltd.
    Inventors: Takemori Takayama, Masanari Furumoto, Chikara Nakao, Noriko Morioka
  • Patent number: 7641850
    Abstract: A technique for net shaping gear teeth of a high performance power transmission gear from a powder metal workpiece includes heating a powder metal workpiece in the form of a near net shaped gear blank having gear teeth surfaces above its critical temperature to obtain an austenitic structure throughout its surfaces, isothermally quenching the workpiece at a rate greater than the critical cooling rate of its surfaces to a uniform metastable austenitic temperature just above the martensitic transformation temperature, rolling the gear teeth surfaces of the workpiece to a desired outer peripheral profiled shape between opposed dies, each die having an outer peripheral profiled surface, while holding the workpiece at the uniform metastable austenitic temperature, the gear teeth surfaces undergoing densification, plastic deformation, and strengthening as a result of the rolling operation, and cooling the workpiece through the martensitic range to thereby harden the surfaces of the gear teeth.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: January 5, 2010
    Assignee: The Penn State Research Foundation
    Inventors: Nagesh Sontti, Maurice F. Amateau, Suren B. Rao
  • Patent number: 7591912
    Abstract: An induction heat treatment method with which temperature control is enabled, condition setting is easy, and the quality of a treatment object can be stabilized includes: a data acquiring step of heating and quench-hardening a sample of the treatment object to thereby acquire process data; a storing step of storing the process data; a checking step of checking the power supply output transition data and the quenching timing data as to validity based on the temperature transition data stored in the storing step; and a mass production step of performing heat treatment of the treatment object in accordance with the power supply output transition data and the quenching timing data stored in the storing step and checked as to validity in the checking step.
    Type: Grant
    Filed: March 21, 2006
    Date of Patent: September 22, 2009
    Assignee: NTN Corporation
    Inventors: Takumi Fujita, Nobuyuki Suzuki
  • Publication number: 20090101246
    Abstract: The present invention provides a method for induction hardening of a steel member having an outer ring portion and, more specifically, for induction hardening of an outer circumferential surface of the outer ring portion. The method uses two pressing members, each of which includes a flat basal surface and a projecting portion projecting therefrom. Each of the projecting portions has a cross-section in the shape of a perfect circle. Also, the projecting portions have, on the outer circumferences thereof, respective pressing surfaces. While gaps are maintained between axial end faces of the outer ring portion and the basal surfaces of the pressing members, the pressing members are pressed against the outer ring portion so that the pressing surfaces each abut against the inner circumference side of the outer ring portion. While a biasing force is applied to the pressing members, the induction hardening process is applied to the outer circumferential surface.
    Type: Application
    Filed: October 21, 2005
    Publication date: April 23, 2009
    Applicant: AISIN AW CO., LTD.
    Inventors: Kouji Ohbayashi, Kazuaki Okada
  • Patent number: 7500310
    Abstract: In making a component part of a reclining device that is used to adjust an inclination of a seat back with respect to a seat cushion, after the component part has been prepared, a predetermined portion of the component part is selectively heated up to a temperature greater than a transformation point of a material of the component part, and the component part is then cooled. During this heat treatment, portions of the component part other than the predetermined portion are left as a base material to thereby selectively increase the strength or the wear and abrasion resistance of the component part.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: March 10, 2009
    Assignee: Delta Kogyo Co., Ltd.
    Inventors: Yasukazu Oki, Shigeki Teraoka
  • Publication number: 20090050622
    Abstract: The invention relates to a process for the continuous heat treatment of steel strip material whose thickness d1, d2 periodically varies along its length, more particularly of strip flexibly rolled with a roll gap varying as a function of time, wherein the continuous heat treatment of the strip material takes place while the strip material passes through an induction furnace in which the strip material is induction heated at a constant frequency which can be selected to be such that the mathematical induction depth ? of the induced current up to which the magnetic field has been reduced to 63% of the field strength of the outer field is greater than half the thickness of the strip portions with the smallest thickness d2.
    Type: Application
    Filed: August 5, 2008
    Publication date: February 26, 2009
    Inventors: Stefan Pohl, Andreas Hauger
  • Patent number: 7438773
    Abstract: A method of manufacturing a blind threaded insert from metal which method comprises the steps of at least partially forming the insert, by a cold-forming process, other than the internal thread; forming the internal thread; and annealing the appropriate part of the insert to promote later deformation during installation.
    Type: Grant
    Filed: October 11, 2001
    Date of Patent: October 21, 2008
    Assignee: Avdel UK Limited
    Inventors: Keith Denham, Matthias Jokisch
  • Patent number: 7422643
    Abstract: There is provided an inexpensive rolling element used under high interface pressure such as induction hardened gears, the rolling element being improved in the seizure resistance of its tooth flanks and having a temper hardness of HRC 50 or more at 300° C. To this end, the rolling element is made from a steel material containing at least 0.45 to 1.5 wt % C and one or more alloy elements selected from 0.1 to 0.5 wt % V and 0.3 to 1.5 wt % Cr, and has a rolling contact surface layer having a structure tempered at low temperature in which 2 to 18% by volume cementite disperses in a martensite parent phase formed by induction heating and cooling and containing 0.25 to 0.8 wt % carbon solid-dissolving therein.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: September 9, 2008
    Assignee: Komatsu Ltd.
    Inventors: Takemori Takayama, Masanari Furumoto, Chikara Nakao, Noriko Morioka
  • Patent number: 6734406
    Abstract: The invention relates to a method for improving the mechanical properties, especially the hardness, of journal crosses for use in articulated shafts. According to the invention, a superficial area which is defined by the transition surfaces between two journals that are adjacent to each other in the peripheral direction and the superficial areas of the peripheral surfaces of the adjacent journals that point in the peripheral direction is induction-hardened in one method step and then quenched with cooling agents.
    Type: Grant
    Filed: August 19, 2002
    Date of Patent: May 11, 2004
    Assignee: Voith Turbo GmbH Co. KG
    Inventors: Hans Lindenthal, Andreas Asch
  • Patent number: 6706127
    Abstract: A method of making a ball-screw rack bar for use in a power steering mechanism of an automotive vehicle. Transverse rack teeth are cut in an exterior surface of a first end portion of a length of a bar stock. A ball-screw thread is cut in an exterior surface of a second end portion of the length of bar stock. The first end portion is heat-treated to a first hardness and the second end portion is heat-treated to a second hardness by passing an induction coil scanner lengthwise over the length of bar stock from one end to the other. The ball-screw thread is cut by whirling. Preferably the heat-treating is carried out after the cutting of the transverse rack teeth and before the cutting of the ball-screw thread. The rack bar produced by this method may be solid or hollow. The rack bar may be made by separately forming two lengths of bar stock and butt-welding them together, or they may be made from a solid length of bar stock.
    Type: Grant
    Filed: December 19, 2002
    Date of Patent: March 16, 2004
    Assignee: Delphi Technologies, Inc.
    Inventors: Ravikiran Duggirala, Craig B. Chritz, Christopher J. Lehti
  • Publication number: 20040035506
    Abstract: A method of manufacturing a blind threaded insert from metal which method comprises the steps of at least partially forming the insert, by a cold-forming process, other than the internal thread; forming the internal thread; and annealing the appropriate part of the insert to promote later deformation during installation.
    Type: Application
    Filed: July 29, 2003
    Publication date: February 26, 2004
    Inventors: Keith Denham, Matthias Jokisch
  • Patent number: 6685596
    Abstract: A blank for disc is heat treated for adjusting a surface hardness thereof to not less than Hv700. The blank has a spline hole thereof heated by high frequency heating while cooling a race thereof. Subsequently, the spline hole is subjected to slow cooling. Thus is obtained a disc having a surface hardness of not less than Hv700 at the race, and a surface hardness of not more than Hv600 at the spline hole, the disc wherein at least a thin portion is varied in hardness between a hardened layer of a bottom of the spline hole and a hardened layer of the race by an amount of not less than Hv20 per 1-mm depth.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: February 3, 2004
    Assignee: Koyo Seiko Company, Ltd.
    Inventors: Masao Goto, Kiichiro Yamashita, Shinji Yasuhara
  • Patent number: 6602358
    Abstract: Disclosed are an outer race for a constant velocity joint, having improved anti-flaking properties and shaft strength, and a process for producing the same. The outer race for a constant velocity joint includes a cup and a serration and comprises by weight carbon: 0.45 to 0.59%, silicon: 0.15 to 0.4%, manganese: 0.15 to 0.45%, sulfur: 0.005 to 0.15%, molybdenum: 0.1 to 0.35%, boron: 0.0005 to 0.005%, aluminum: 0.015 to 0.05%, and titanium: 0.015 to 0.03%, the proportion of the effective case depth in track grooves of the cup being 0.25 to 0.45 in terms of the ratio of the effective case depth t to the wall thickness of the cup w, t/w, the proportion of the effective case depth of the involute serration in its end being 0.20 to 0.50 in terms of the ratio of the effective case depth t to the radius r, t/r. The involute serration in its end preferably has a former austenite grain size of not less than 8 in terms of the grain size number specified in JIS (Japanese Industrial Standards).
    Type: Grant
    Filed: November 18, 1999
    Date of Patent: August 5, 2003
    Assignees: Nippon Steel Corporation, Honda Motor Co., Ltd.
    Inventors: Tatsuro Ochi, Hideo Kanisawa, Kenichiro Naito, Joji Tamura, Masayoshi Saga
  • Patent number: 6548793
    Abstract: An apparatus and method to inductively heat beveled gear teeth. An inductor has an annular body with a plurality of projections for meshingly engaging beveled of the gear. An inductor coil or loop is associated with each of the projections and is at least partially disposed between successive gear teeth to induce a magnetic flux directly there through when engaging the beveled gear. By simply rotating the inductor relative to the beveled gear while simultaneously sending a current through the coil, successive gear teeth are treated. Preferably, the number of gear teeth differs from the number of projections, and the beveled gear is rotated sufficiently to ensure that each of the projections and associated coil engages each of the beveled gear teeth to facilitate a more uniform treatment.
    Type: Grant
    Filed: June 29, 2001
    Date of Patent: April 15, 2003
    Assignee: Torque-Traction Technologies, Inc.
    Inventor: Todd A. Smith
  • Patent number: 6502473
    Abstract: A rack bar of a power steering unit for a vehicle has improved bending strength. The rack bar includes a rod portion which fits slidably into an oil seal attached to a cylinder portion of a power cylinder, and a rack portion which is formed with the rod portion through a connecting portion and which meshes with a pinion. Quenching is applied the rod portion and to the rack portion, preferably under different conditions. The quenching applied to the rack portion also is applied to at least a portion of the connecting portion.
    Type: Grant
    Filed: September 21, 2000
    Date of Patent: January 7, 2003
    Assignees: Toyota Jidosha Kabushiki Kaisha, TRW Automotive Japan Co., Ltd.
    Inventors: Kazuhiro Akiyama, Tomomi Fujii, Takashi Yamawaki
  • Patent number: 6315841
    Abstract: Bevel gears having a carbon content of at least about 0.4% by weight, preferably 0.5% by weight are manufactured by a process which includes forging a steel blank having a carbon content of at least 0.4% by weight until a bevel gear precursor having essentially the tooth configuration and dimensions of the desired product gear is obtained, and hardening the teeth of the gear precursor by induction heating without machining of the teeth. The initial forging is precise enough so that no further machining of the teeth is required. This requires forging to a tolerance specified in AGMA class 6. The gear is then induction hardened, first by preheating at a lower frequency, say 10 KHz, then induction heating at a higher frequency, say 50 KHz, in order to obtain a desired hardness profile. The desired hardness profile includes the surface hardness of at least 50, preferably 60, on the Rockwell C scale and a core hardness not over Rockwell C 45, preferably from Rockwell 25 to Rockwell 40.
    Type: Grant
    Filed: December 31, 1999
    Date of Patent: November 13, 2001
    Assignee: Dana Corporation
    Inventors: James S. Fisher, Roland C. Smith
  • Patent number: 6264768
    Abstract: A method and apparatus disclosed for cost-effective net shape precision ausform finishing the engagement surfaces of ball and roller bearings, for enhancing the surface strength and durability of bearing inner and outer races. The method consists of induction heating to austenitize the contacting surface layers of rolling element bearing races, followed by martempering (or marquenching), and then net shape roll finishing of the induction heated contacting surface layers in the metastable austenitic condition to finished dimensional accuracy requirements, and finally cooling to martensite. The apparatus utilizes a fixed vertical through-feed axis for the workpiece bearing race with capability for rotation and linear up and down positioning motion, and two coordinated and controlled laterally-moving infeed axes for roll finishing tooling dies.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: July 24, 2001
    Assignee: The Penn State Research Foundation
    Inventors: Nagesh Sonti, Suren B. Rao
  • Patent number: 6259076
    Abstract: A method for simultaneously hardening a group of cams on a camshaft comprises first heating the group of cams at low power for at least one heating interval, then pausing the heating for a pause interval during which no power is applied to the group of cams, and then subsequently heating the group of cams at high power for one heating interval. The pause intervals, during which no power is applied to the group of cams, are sufficient as to allow heat stored in the cams to distribute uniformly throughout the cams. Each group of cams is hardened by a linear inductor and the regions of the camshafts that are not to be hardened are shielded by a cooling device.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: July 10, 2001
    Assignee: Elotherm GmbH
    Inventors: Waldemar Gezarzick, Hans-JĂ¼rgen Leisner, Peter Schulte
  • Patent number: 6129794
    Abstract: A method of manufacturing a gear wheel including a shaft and a tooth system. The method includes the steps of hardening and annealing the gear wheel, heating the gear wheel to an annealing temperature, spinning the gear wheel when the annealing temperature is reached, spinning the gear wheel while cooling the gear wheel and grinding the gear wheel to a final size. The method allows the manufacture of gear wheels having an increased service life.
    Type: Grant
    Filed: August 28, 1998
    Date of Patent: October 10, 2000
    Assignee: Asea Brown Boveri AG
    Inventor: Hans Wettstein
  • Patent number: 6129793
    Abstract: A face-gear forging die which can be used to near-net forge face gears is disclosed. The face-gear forging die is constructed from a blank, and is cut to specification using a wire electrical discharge machining (EDM) process. The wire electrical discharge machining process is computer controlled, according to pre-specified instructions. Accordingly, a variety of different-shaped face-gear forging die may be constructed by merely changing the specification's input to the wire Electric Discharge Machining apparatus. The wire Electric Discharge Machining process can also be used to cut the face gear tooth directly, to thereby circumvent the forging procedure. The complex, curved surfaces of the face gear teeth are mathematically approximated with a ruled surface, and the mathematical approximation is input to the wire Electric Discharge Machining apparatus for subsequent execution and forming of the die.
    Type: Grant
    Filed: August 11, 1997
    Date of Patent: October 10, 2000
    Inventors: Jie Tan, Terrell W. Hansen
  • Patent number: 6019857
    Abstract: Power transmission member such as gears with high breaking strength of the edge portion (A) of the root and high spalling resistance of the tooth side (B) is obtained. The work such as gears, etc. is cooled after carburization by plasma carburizing, etc. and the work surface is high-frequency hardened, and for heating at the time of high-frequency hardening, the heating conditions are set in such a manner that the heating temperature at the root becomes higher than that at the tooth side and time for holding to high temperature becomes long. This promotes solid solution of carbonate at the root and increases the remaining austenite volume after hardening (25-35% for a good-rule-of-thumb) as well as improves toughness at the edge. On the other hand, on the tooth side, the remaining austenite volume decreases (5-15% for a good-rule-of-thumb) and spalling resistance improves.
    Type: Grant
    Filed: June 24, 1997
    Date of Patent: February 1, 2000
    Assignee: Mazda Motor Corporation
    Inventor: Akira Mutagami
  • Patent number: 6011246
    Abstract: An induction heating device for surface treating the teeth (11) of a mechanical part on which each tooth (111) has a projecting tip (111s) and a tooth root linking the tooth to an adjacent tooth, wherein an in duction coil (12, 12') is spaced from the tooth tips and powered by at least one high-frequency current source. The coil consists of a set of conductive segments (24, 24') individually orthogonal to the generatrix (d, d') of the teeth, located above respective tooth tips and interconnected via connecting segments (25, 25').
    Type: Grant
    Filed: December 11, 1998
    Date of Patent: January 4, 2000
    Assignees: Renault, Ensam Bordeaux, Saet
    Inventors: Giorgio Bonzano, Bernard Criqui, Maria Dias De Sousa, Olivier Longeot
  • Patent number: 5824168
    Abstract: According to the present invention, in a heating step, an outer circumferential portion of a workpiece having a disk shape is heated to high temperatures. In a hot rough-rolling step, the outer circumferential portion of the heated workpiece is formed by use of a roller die to generate a rolled-gear having teeth. In a warm finish-rolling step, the teeth of the rolled-gear are finish-rolled by use of the finishing roller die. The starting temperature T.sub.1 of the hot rough-rolling step is set in the range of from 850.degree. through 1100.degree. C., the terminating temperature of the hot rough-rolling step T.sub.2 is set in the range of from 500.degree. through 700.degree. C. The starting temperature T.sub.3 of the warm finish-rolling step is set in the range of from 400.degree. through 700.degree. C., and the terminating temperature of the warm finish-rolling step T.sub.4 is set in the range of from 200.degree. through 650.degree. C.
    Type: Grant
    Filed: September 4, 1996
    Date of Patent: October 20, 1998
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Noritaka Miyamoto, Masazumi Onishi, Yasuyuki Fujiwara, Toshiaki Tanaka, Masatoshi Sawamura, Atsushi Danno
  • Patent number: 5803993
    Abstract: The present invention provides an outer ring for a high strength constant velocity joint which has an excellent torsional strength and torsional fatigue strength and can provide an improved processability, and a process for producing the same. An outer ring used for a high strength constant velocity joint having an involute serration part and a screw part, the outer ring made of a steel containing:C: 0.45 to 0.53%, Si: 0.05 to 0.25%, Mn: 0.7 to 1.0%, Al: 0.01 to 0.05%, Mo: 0.2 to 0.4%, N: 0.003 to 0.012%, the remainder being Fe and inevitable impurities, the inevitable impurities including:Cr: 0.05% or less than 0.05%, P: 0.015% or less than0.015%, S: 0.01% or less than 0.01%, and O: 0.002% orless than 0.002%,wherein an old austenite crystal grain at the involute serration end is 8 or more in JIS grain size classification; a surface hardness at the end is 720 or more in Hv; and a ratio (CD/R) is 0.35 to 0.
    Type: Grant
    Filed: October 17, 1996
    Date of Patent: September 8, 1998
    Assignee: NTN Corporation
    Inventors: Kazuhiko Yoshida, Tatsuhiro Goto, Akira Wakita, Toshio Kawasaki, Toyofumi Hasegawa, Hideo Takeshita, Toshiki Suwa
  • Patent number: 5562785
    Abstract: A disc-shaped material is prepared by punching a high carbon steel plate or soft steel plate, and the disc-shaped material is fixed in position. An outer peripheral portion of the disc-shaped material is heated to a temperature of 400.degree.-500.degree. C. y means of a high frequency heater. The outer peripheral portion of the disc-shaped material is swaged to form a thickened portion by a swaging die and the thickened portion is then spun to plastically form a toothed gear to the outer peripheral portion of the disc-shaped material in two steps of coarse working and finish working by spinning dies. The thus formed toothed gear is further heated as occasion demands to a temperature of about 900.degree. C. for quenching.
    Type: Grant
    Filed: April 18, 1995
    Date of Patent: October 8, 1996
    Assignee: Kubota Iron Works Co., Ltd.
    Inventor: Shigeaki Yamanaka
  • Patent number: 5473960
    Abstract: A steering rack shaft having a shaft body and rack teeth formed in a predetermined axial region of the shaft body. This steering rack shaft is formed such that a workpiece is quenched, and is then heated for a predetermined time at a temperature exceeding 400.degree. C. so as to be thermally refined, and the rack teeth are subsequently formed. After the formation of the rack teeth, high-frequency induction hardening is provided to form a teeth-hardened layer. Hence, the machining of the rack teeth is facilitated while reducing strain, and the rigidity and toughness of the overall steering rack shaft are improved.
    Type: Grant
    Filed: March 10, 1994
    Date of Patent: December 12, 1995
    Assignee: Kabushiki Kaisha Yamada Seisakusho
    Inventors: Hideji Sakamoto, Masayoshi Ozawa, Seiji Kanuki, Kenji Hoshino, Toshiaki Tanaka
  • Patent number: 5451275
    Abstract: An apparatus and method are provided for the thermomechanical net shape finishing of precision gear tooth surfaces by controlled deformation into metastable austenitic condition. To this end, an arrangement of a fixed axis through-feed motion of workpiece and moving axes in-feed motion of two opposed rolling dies are utilized. By means of process control methods and architecture for accomplishing precision mechanical motions, thermal and environmental control and timely and automatic transfer of workpiece, high strength and high accuracy gear tooth contact surfaces are produced.
    Type: Grant
    Filed: August 4, 1994
    Date of Patent: September 19, 1995
    Assignee: The Penn State Research Foundation
    Inventors: Maurice F. Amateau, Nagesh Sonti
  • Patent number: 5428208
    Abstract: A method of case hardening a steering gear rack bar having a plain cylindrical barrel portion and an integral toothed portion on which are formed a plurality of rack gear teeth each having a predetermined helix angle relative to a longitudinal centerline of the rack bar. The method includes forming an induction coil having a linear section and a spiral section with a helix angle equal to the helix angle of the rack gear teeth, locating the rack bar inside the induction coil with the barrel portion thereof juxtaposed the linear section of the induction coil and with the spiral section of the induction coil surrounding the toothed portion, rotating the rack bar about its longitudinal centerline while passing alternating electric current through the coil to concurrently induction heat both the barrel portion and the toothed portion, and quenching the rack bar after the alternating current is turned off.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: June 27, 1995
    Assignee: General Motors Corporation
    Inventors: Madhu S. Chatterjee, William I. Stuehr
  • Patent number: 5411612
    Abstract: A method and apparatus for carrying out scaleless inductive heating of ferrous parts comprising (i) using an integrated manifold-inductor quenchant device, and while gradually flowing a diluted combustible gas into the spacing between the inductor and part surface to be heated, inductively heating such surface as part of a heat treating cycle; and (ii) concurrently stopping such flow and injecting a fluid quenchant through the spacing to rapidly lower the temperature of the part surface to complete the heat treating cycle. Advantageously such method may further comprise flushing the spacing between the inductor and heated part surface, and then repeating the steps of the prior method to treat more parts with the same inductor.
    Type: Grant
    Filed: December 27, 1993
    Date of Patent: May 2, 1995
    Assignee: Ford Motor Company
    Inventor: Mark G. Shapona
  • Patent number: 5374809
    Abstract: An induction heating device includes a handle having a hollow interior and two opposite ends, a wrist connected to one end of the handle, a U-shaped pole piece having two spaced apart ends, a tank circuit including an induction coil wrapped around the pole piece and a capacitor connected to the induction coil, a head connected to the wrist and including a housing for receiving the U-shaped pole piece, the two spaced apart ends of the pole piece extending outwardly beyond the housing, and a power source connected to the tank circuit. When the tank circuit is energized and a susceptor is placed in juxtaposition to the ends of the U-shaped pole piece, the susceptor is heated by induction heating due to a magnetic flux passing between the two ends of the pole piece.
    Type: Grant
    Filed: May 12, 1993
    Date of Patent: December 20, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Robert L. Fox, Samuel D. Johnson, Carl E. Copeland, Robert H. Coultrip, W. Morris Phillips, David F. Johnston, Robert J. Swaim, James R. Dinkins
  • Patent number: 5373143
    Abstract: A method and apparatus for measuring the temperature and heating rate of a workpiece during the induction heating cycle by inducing and detecting a plurality of eddy current pulses at varying frequencies during a short power interruption to the induction coil and correlating the pulses to generate a workpiece profile which is compared to a reference profile to determine whether to reject the inductively heated workpiece.
    Type: Grant
    Filed: July 6, 1993
    Date of Patent: December 13, 1994
    Assignee: Tocco, Inc.
    Inventor: George D. Pfaffmann
  • Patent number: 5360963
    Abstract: An induction-hardening machine for the contour hardening of cross-axis, intersecting-axis and nonintersecting-axis gears such as hypoid gears includes a programmable logic control unit, a source of quench liquid and a high-frequency induction generator which are operably connected to a high-frequency induction coil which, in one embodiment, is disposed at an inclined angle above the horizontally disposed workpiece (hypoid gear). Fluid connections are made between the source of quench liquid and the induction coil for the rapid delivery of quench liquid. The support platform for the hypoid gear is connected to a rotary drive motor and with the hypoid gear rotating at approximately 900 to 1800 RPM the induction coil is energized with four low energy pulses of relatively short duration. The final heating step is a high energy pulse followed immediately by the quenching step.
    Type: Grant
    Filed: February 8, 1993
    Date of Patent: November 1, 1994
    Assignee: Contour Hardening, Inc.
    Inventors: John M. Storm, Michael R. Chaplin
  • Patent number: 5282910
    Abstract: A metal alloy workpiece is heated convectively in a first step by heat conduction, heat radiation or further non-inductive heat transfer to a temperature lying just below the solidus temperature of the alloy and is heated inductively in a subsequent second step to the final temperature lying between solidus and liquidus temperature. The process is particularly suitable for producing workpieces having thixotropic properties intended for further processing, in particular for further processing bolts or bars in die-casting, forging, rolling and pressing plants.
    Type: Grant
    Filed: May 26, 1992
    Date of Patent: February 1, 1994
    Assignee: Alusuisse-Lonza Services Ltd.
    Inventors: Jean-Pierre Gabathuler, Yves Krahenbuhl
  • Patent number: 5242514
    Abstract: A method for the production of a hardened guide shaft for linear guide is disclosed, in which teeth are formed in a shaft, which is then passed through a circular inductor without rotation. The magnetic flux of the circular inductor is controlled to reduce the flux in the area of the teeth, thereby hardening the teeth without overheating them. The remainder of the shaft is hardened through a magnetic flux greater than that supplied to the teeth area.
    Type: Grant
    Filed: February 13, 1991
    Date of Patent: September 7, 1993
    Inventors: Richard Wiener, Rolf Merz