Induction hardening system and method

Patent metadata

Field	Value
Publication number	US-9631252-B2
Application number	US-201313871721-A
Country	US
Kind code	B2
Filing date	Apr 26, 2013
Priority date	Apr 9, 2010
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

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.

First claim

What is claimed is:

1. An induction heat treatment workstation for hardening a gear, the gear having an inner surface bearing a plurality of groups of splines, the groups of splines being separated by webs, the workstation comprising:
an inductor coil including a plurality of heating loops and a plurality of non-heating loops, wherein the heating loops are adjacent to and alternate with the non-heating loops around a circumference of the gear, the inductor coil being energizable by an alternating current power source, the inductor coil being operable to create an alternating magnetic field when energized to a predetermined frequency, the alternating magnetic field being configured to induce an eddy current in the plurality of groups of splines of the gear to induction harden the gear at the plurality of groups of splines, wherein the non-heating loops comprise first and second portions that are parallel to each other, wherein the first and second portions of the non-heating loops are disposed parallel to an axis of rotation of the rotational mechanism, wherein each of the first and second portions of the non-heating loops creates a portion of the alternating magnetic field, wherein the portion of the alternating magnetic field created by the first portion cancels the portion of the alternating magnetic field created by the second portion; and
a rotational mechanism operable to rotate the gear about an axis of rotation, the rotational mechanism operable to rotate the gear relative to the inductor coil.

2. The workstation of claim 1 further comprising a quench plate, wherein the quench plate includes portions forming a plurality of fluid passageways that are in fluid communication with a fluid source, and wherein the portions forming the plurality of fluid passageways are configured to communicate fluid to the inner surface of the gear.

3. The workstation of claim 2 wherein the inductor coil is secured to the quench plate.

4. The workstation of claim 3 wherein the quench plate includes a flux intensifier formed therein.

5. The workstation of claim 1 wherein the heating loop is oriented in a non-parallel position with respect to the first and second portions of the non-heating loop.

6. The workstation of claim 5 further comprising a power source operable to provide alternating current to the inductor coil.

7. The workstation of claim 6 wherein the at least one heating loop is a plurality of heating loops and the at least one non-heating loop is a plurality of non-heating loops, the heating and non-heating loops being alternatively disposed with one another around the quench plate.

8. An induction heat treatment workstation for hardening a gear, the gear having an inner surface bearing a plurality of groups of splines, the groups of splines being separated by webs, the workstation comprising:
an inductor coil including a plurality of heating loops and a plurality of non-heating loops, the heating loops being adjacent to and alternating with the non-heating loops around a circumference of the gear, each non-heating loop having a first portion and a second portion, the first and second portions being parallel to each other, each of the plurality of heating loops being oriented in a non-parallel position with respect to the first and second portions of each of the plurality of non-heating loops, the inductor coil being energizable by an alternating current power source, the inductor coil being operable to create an alternating magnetic field when energized to a predetermined frequency, the alternating magnetic field being configured to induce an eddy current in the plurality of groups of splines of the gear to induction harden the gear at the plurality of groups of splines;
a rotational mechanism operable to rotate the gear about an axis of rotation, the rotational mechanism operable to rotate the gear relative to the inductor coil, the first and second portions of each of the plurality of non-heating loops being disposed parallel to an axis of rotation of the rotational mechanism; and
a quench plate secured to the inductor coil, wherein the quench plate includes portions forming a plurality of fluid passageways that are in fluid communication with a fluid source, and wherein the portions forming the plurality of fluid passageways are configured to communicate fluid to the inner surface of the gear, the quench plate including a flux intensifier formed therein,
wherein each of the first and second portions of each of the plurality of non-heating loops creates a portion of the alternating magnetic field, wherein for each of the plurality of non-heating loops, the portion of the alternating magnetic field created by the first portion cancels the portion of the alternating magnetic field created by the second portion.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Chatterjee Madhu Sudan
• Stuehr William Irwin

Classifications

• H05B6/405

  for heating gear-wheels · CPC title

• C21D1/62

  Quenching devices · CPC title

• C21D1/42

  Induction heating · CPC title

• C21D1/10

  by electric induction · CPC title

• C21D9/32 Primary

  for gear wheels, worm wheels, or the like · CPC title