Nagesh Sonti

US Patent:

6779270, Aug 24, 2004

Filed:

Jan 24, 2002

Appl. No.:

10/056928

Inventors:

Nagesh Sonti - State College PA
Suren B. Rao - State College PA
James V. Caldwell - Warren MI

Assignee:

The Penn States Research Foundation - University Park PA

International Classification:

B21D 5328

US Classification:

2989332, 298933, 2989334, 72108

Abstract:

A full form net shape roll finished contacting machine element such as a gear or sprocket is produced from a near net shape workpiece of wrought or forged steel including teeth with an initial outer peripheral contoured surface, each having a tooth flank with a nominally involute surface and a root/fillet region with a trochoidal surface. A rolling die is rotatably supported on a first axis. With the workpiece rotatably supported on a parallel distant second axis, the rolling die is advanced in an in-feed direction to meshingly engage with the workpiece. The involute surface of each tooth of the rolling die engages the involute surface of a mating tooth of the workpiece and the tooth tip of the rolling die engaging the trochoidal root/fillet surface between adjacent mating teeth of the workpiece to effect material flow along the outer peripheral contoured surface. This process continues for all of the teeth of the workpiece.

US Patent:

20040219051, Nov 4, 2004

Filed:

Mar 17, 2004

Appl. No.:

10/802141

Inventors:

Nagesh Sonti - State College PA, US
Maurice Amateau - State College PA, US
Suren Rao - Boalsburg PA, US

International Classification:

B22F005/08

US Classification:

419/031000

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.

US Patent:

61268925, Oct 3, 2000

Filed:

Nov 12, 1999

Appl. No.:

9/439540

Inventors:

Maurice F. Amateau - State College PA
Nagesh Sonti - State College PA

Assignee:

The Penn State Research Foundation - University Park PA

International Classification:

C21D 932

US Classification:

266118

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.

US Patent:

62647687, Jul 24, 2001

Filed:

Apr 23, 1999

Appl. No.:

9/298375

Inventors:

Nagesh Sonti - State College PA
Suren B. Rao - State College PA

Assignee:

The Penn State Research Foundation - University Park PA

International Classification:

C21D 110

US Classification:

148567

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. For finishing of the outer contacting surfaces of the bearing inner races, two suitably contoured power-driven dies are arranged symmetrically on diametrically opposing sides of the workpiece. A dual but asymmetric tooling arrangement employs a suitably contoured power-driven finish tooling die is positioned for the internal roll finishing operation, while a plane cylindrically shaped idling support tooling die is located on the opposing side of the work region.

US Patent:

52215130, Jun 22, 1993

Filed:

Jan 31, 1992

Appl. No.:

7/829187

Inventors:

Maurice F. Amateau - State College PA
G. Dwayne Kidwell - State College PA
Nagesh Sonti - State College PA

Assignee:

The Penn State Research Foundation - University Park PA

International Classification:

C21D 932

US Classification:

266 81

Abstract:

An apparatus is disclosed for performing thermomechanical processing of gears in which precise control of the thermal, metallurgical and mechanical action during the forming process is maintained. The apparatus comprises an induction heating system which reaustenitizes the surface of the gear with minimum decarburization, a material transfer system which provides timely operations on the work piece, tooling and fixture adjustments which provide accurate initial conditions for forming, and a process control architecture that provides the precise sequence and timing necessary to achieve metallurgically sound and dimensionally accurate gears. Using this invention the induction heating cycle can be controlled from the peak, average or minimum gear surface temperature detected with a high response optical pyrometer. An inert environment is maintained around the workpiece during the induction heating and transfer to quenching above the M. sub. s temperature.

US Patent:

6007762, Dec 28, 1999

Filed:

Nov 18, 1997

Appl. No.:

8/972938

Inventors:

Maurice F. Amateau - State College PA
Nagesh Sonti - State College PA

Assignee:

The Penn State Research Foundation - University Park PA

International Classification:

C21D 932

US Classification:

266118

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.

US Patent:

56561067, Aug 12, 1997

Filed:

Dec 21, 1994

Appl. No.:

8/360506

Inventors:

Maurice F. Amateau - State College PA
G. Dwayne Kidwell - State College PA
Nagesh Sonti - State College PA

Assignee:

The Penn State Research Foundation - University Park PA

International Classification:

C21D 932

US Classification:

148586

Abstract:

An apparatus is disclosed for performing thermomechanical processing of gears in which precise control of the thermal, metallurgical and mechanical action during the forming process is maintained. The apparatus comprises an induction heating system which reaustenitizes the surface of the gear with minimum decarburization, a material transfer system which provides timely operations on the work piece, tooling and fixture adjustments which provide accurate initial conditions for forming, and a process control architecture that provides the precise sequence and timing necessary to achieve metallurgically sound and dimensionally accurate gears. The induction heating cycle can be controlled from the peak, average or minimum gear surface temperature detected with a high response optical pyrometer. An inert environment is maintained around the workpiece during the induction heating and transfer to quenching above the M. sub. s temperature.

US Patent:

57993980, Sep 1, 1998

Filed:

Sep 18, 1995

Appl. No.:

8/529774

Inventors:

Maurice F. Amateau - State College PA
Nagesh Sonti - State College PA

Assignee:

The Penn State Research Foundation - University Park PA

International Classification:

B21D 5328

US Classification:

2989332

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.