Patents Assigned to NTN Technical Center
  • Patent number: 5602946
    Abstract: An improved fiber optic sensor system and integrated sensor bearing assembly for detecting movement or position of a rotating wheel bearing having a multi-pole tone ring which produces an alternating magnetic field indicative of movement and position of the rotating member. A magneto-optical material, such as a bismuth garnet iron (B.I.G.) crystal, having discrete magnetic domains is positioned in the vicinity of the tone ring so that the domains align themselves to the magnetic field generated by the tone ring. A single fiber optic cable, preferably single mode fiber, carries light generated by a source of light to the B.I.G. crystal. The light passes through the B.I.G. crystal and is refracted at domain boundaries in the crystal. The intensity of the refracted light is indicative of the amount of alignment of the domains and therefore the strength of the magnetic field.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: February 11, 1997
    Assignee: NTN Technical Center (USA)
    Inventors: Lynn R. Veeser, Patrick J. Rodriguez, Peter R. Forman, Russell E. Monahan, Jonathan M. Adler
  • Patent number: 5496646
    Abstract: Iron and steel interference fit assemblies with increased retention forces comprised of a purposely formed iron oxide layer of limited thickness on one or both of the mutually engaging surfaces. The new methods to create the new interference fit assemblies comprise heating of iron and steel parts intended for press fit assembly to temperatures substantially between 500.degree. F. (260.degree. C.) and 1050.degree. F. (566.degree. C.) for periods of time in air between ten hours and ten minutes to create an iron oxide surface layer of optimum thickness on at least one of the mutually engaging surfaces prior to assembly. Other methods to generate the optimum thickness of iron oxide layer may also be used. The iron oxide surface layer substantially increases the frictional retention force in the assembly. The retention force effectively doubles with heating at 700.degree. F. (371.degree. C.) to 800.degree. F. (427.degree. C.
    Type: Grant
    Filed: December 2, 1993
    Date of Patent: March 5, 1996
    Assignee: NTN Technical Center (U.S.A.), Inc.
    Inventor: Nelson A. Bacigalupo
  • Patent number: 5381090
    Abstract: A bearing assembly incorporating a speed and/or temperature sensor particularly adapted for motor vehicle wheel applications. The sensor incorporates a magnetized tone ring defining a radial or cylindrical face which interacts with an annular transducer. The transducer has a plurality of teeth facing the magnetized tone ring with separate first and second rows of teeth extending from the transducer frame. The first set of teeth engage one area of the tone ring defining one magnetic pole whereas the second series of teeth interact with regions of the tone ring defining the opposite magnetic pole. Relative rotation between the transducer and tone ring induces an alternating magnetic field through the transducer case which induces an alternating voltage in the winding coil. The transducer is efficiently packaged within the enclosed cavity of a bearing assembly. This invention further contemplates a means to allow transducer temperature to be evaluated by monitoring the DC resistance of the transducer winding.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: January 10, 1995
    Assignee: NTN Technical Center
    Inventors: Jonathan M. Adler, Kevin J. Fontenot
  • Patent number: 5184069
    Abstract: A hub and bearing assembly particularly adapted for motor vehicle application having anti-lock braking system (ABS). Wheel speed sensors are provided in accordance with this invention having a tone wheel configured from a support substrate having a layer of magnetic ink coated thereon. The magnetic ink is magnetized after coating and can be used in conjunction with passive sensors such as variable reluctance types, or active sensors including semi-conductor Hall effect types. The wheel speed sensors of this invention can be adapted for driven or non-driven wheel applications and are sufficiently compact to enable the device to be integrated into the bearing structure and protected from environmental exposure.
    Type: Grant
    Filed: December 3, 1991
    Date of Patent: February 2, 1993
    Assignee: NTN Technical Center, (U.S.A.) Inc.
    Inventors: Jonathan M. Adler, Russell E. Monahan, Robert W. Frayer, Jr.
  • Patent number: 5099884
    Abstract: A fluid control valve of "Wheatstone Bridge" arrangement for use with electrorheological fluids comprises a plurality of channel plates and printed circuit board plates alternatingly stacked together. Electrodes are printed on the printed circuit board plates to form walls on sides of channels formed in the channel plates. Holes piercing the printed circuit board plates are so located as to permit the flow of fluid through the printed circuit board plates from channel plate to channel plate at specific locations thereby causing the flow of fluid through a "Wheatstone Bridge" arrangement. Electric activation of selected electrodes cause the flow of fluid in channels between the selected electrodes to become exceedingly viscous or "freeze" and thereby close selected portions of the "Wheatstone Bridge". In the most common arrangement closure of parallel valves cause flow through the cross arm of the "Wheatstone Bridge" and actuation of an hydraulic device connected into the cross arm.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: March 31, 1992
    Assignee: NTN Technical Center (U.S.A.), Inc.
    Inventor: Russell E. Monahan