Multi-frequency heat treatment of a workpiece by induction heating
AssigneeInductoheat, Inc.
InventorsDon L. Loveless, Valery I. Rudnev
Life of this patent
Estimating the term…
Abstract
An apparatus and process are provided for multi-frequency induction heat treatment of workpieces including gears. High frequency power is applied to an induction coil that surrounds the workpiece so that a high frequency magnetic field couples with the workpiece to inductively heat the workpiece. A C-core inductor is coupled to a coil that has low frequency power applied to it. The workpiece is inserted in a gap in the C-core inductor magnetic circuit so that it experiences low frequency Joule effect heating when the low frequency current is applied to the coil coupled with the C-core inductor. Alternatively the workpiece may be inserted around the C-core inductor when the workpiece has an opening.
Claims13
A method of heating a workpiece comprising the steps of:
- placing the workpiece at least partially within an induction coil to magnetically couple the workpiece with a first ac magnetic field generated by the flow of a first ac current in the induction coil to inductively heat the workpiece;
- forming at least one magnetic circuit from the workpiece and at least one generally C-shaped inductor;
- and
- supplying a second ac current in at least one solenoidal coil wound around a section of the at least one generally C-shaped inductor to magnetically couple the at least one magnetic circuit with a second ac magnetic field generated by the flow of a second ac current in the solenoidal coil to heat the workpiece, the frequency of the first ac current greater than the frequency of the second ac current.
A method of heating a rotatable workpiece comprising the steps of:
- placing the workpiece at least partially within an induction coil to magnetically couple the workpiece with a first ac magnetic field generated by the flow of a first ac current in the induction coil to inductively heat the workpiece;
- forming at least one magnetic circuit from the workpiece and a generally C-shaped inductor;
- rotating the workpiece while the workpiece is at least partially within the induction coil;
- and
- supplying a second ac current in at least one solenoidal coil wound around a section of the generally C-shaped inductor to magnetically couple the at least one magnetic circuit with a second ac magnetic field generated by the flow of a second ac current in the solenoidal coil to heat the workpiece, the frequency of the first ac current greater than the frequency of the second ac current.
A method of heating a rotatable workpiece comprising the steps of:
- placing the workpiece at least partially within an induction coil to magnetically couple the workpiece with a first ac magnetic field generated by the flow of a first ac current in the induction coil to inductively heat the workpiece;
- forming at least one magnetic circuit from the workpiece and at least one generally C-shaped inductor,
- rotating the workpiece while the workpiece is at least partially within the induction coil;
- and
- supplying a second ac current in at least one solenoidal coil wound around a section of the at least one generally C-shaped inductor to magnetically couple the at least one magnetic circuit with a second ac magnetic field generated by the flow of a second ac current in the solenoidal coil to heat the workpiece, the frequency of the first ac current greater than the frequency of the second ac current.
A method of heating a rotatable workpiece comprising the steps of:
- placing the workpiece at least partially within an induction coil to magnetically couple the workpiece with a first ac magnetic field generated by the flow of a first ac current in the induction coil to inductively heat the workpiece;
- forming at least one magnetic circuit from the workpiece and a generally C-shaped inductor;
- rotating the workpiece while the workpiece is at least partially within the induction coil;
- supplying a second ac current in at least one solenoidal coil wound around a section of the generally C-shaped inductor to magnetically couple the at least one magnetic circuit with a second ac magnetic field generated by the flow of a second ac current in the solenoidal coil to heat the workpiece, the frequency of the first ac current greater than the frequency of the second ac current;
- and
- moving a segment of the generally C-shaped inductor to replace the workpiece.
Dependencies are inferred from the claim text.