Method for producing gears

• US 4,709,569 A
• Filed: 05/02/1983
• Issued: 12/01/1987
• Est. Priority Date: 02/25/1981
• Status: Expired due to Fees

• Current Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Sabroff, Alvin M., Ream, James C., Chambers, Samuel C.
• Primary Examiner(s): Larson, Lowell A.
• Application Number:
  US06/484,800
• Time in Patent Office: 1,674 Days
• Field of Search: 72/38, 72/39, 72/340, 72/342, 72/364, 72/377, 148/12 F
• US Class Current: 72/340
• CPC Class Codes: B21J 1/06 Heating or cooling methods or arrangements specially adapted for performing forging or pressing operations B21J5/063 takes precedence
• CPC Class Codes: B21J 5/00 Methods for forging, hammering, or pressing for working sheet-metal or metal tubes, rods, or profiles B21D; for working wire B21F; Special equipment or accessories therefor
• CPC Class Codes: C21D 7/13 by hot working

Abstract

A method for precision forging of low to medium carbon level carbon and/or alloy steels is provided. The method include the steps of heating the properly prepared billets (20), preferably in a minimum oxidizing environment (36), to a preselected temperature falling in the range of 0.68-0.74, preferably 0.69-0.73, of the homologous temperature ratio (HTR) of the billet material and then precision forging the heated billets while at the preselected temperature.

Claims

1. A method of producing a spur or bevel gear of low to medium carbon level carbon or allow steel comprising the steps of:

(a) providing a properly sized, shaped and cleaned billet of a given low to medium carbon level carbond or ally steel having a carbon content of not more than 0.30%;

(b) heating the billet in a minimum oxidizing environment to a preselected temperature falling in the range of 0.069-0.71 for the homologous temperature ratio of the billet material;

(c) locating the heated billet in a first die member on a forging machine;

(d) precision forging the billet while substantially at said preselected temerature by engaging the heated billet with a second die member complementary with the first die member in a single forge flow to form a gear precision preform;

(e) removing the preform and allowing the preform to cool in air to substantially ambient temperature; and

(f) machining less than 0.060 inch of material from the exterior functional surfaces of the cooled preform without subjecting the cooled preform to any heat treating operation prior to said machining.

2. The process of claim 1, wherein the machining of step f) comprises machining less than 0.030 inch of material from the exterior functional surfaces of the cooled preform.

3. A method of producing a spur or bevel gear of low to medium carbon level carbon or alloy steel comprising the steps of:

(a) providing a properly sized, shaped and cleaned billet of a given low to medium carbon level carbon or alloy steel having a carbon content of not more than 0.30%;

(b) heating the billet in a minimum oxidizing environment to a preselected temperature falling in the range of 0.71-0.74 for the homologous temperature ratio of the billet material;

(c) locating the heated billet in a first preform die member on a forging machine;

(d) forging the billet while substantially at said preselected temperature by engaging the heated billet with a second preform ide member complementary with the first preform die member to form a gear close tolerance preform;

(e) immediately locating the gear close tolerance preform in a first finish die member on a forging mahcine;

(f) forging the gear close tolerance preform by engaging the gear preform with a second finish die member complementary with the first finish die member to form a precision forging;

(g) removing the precision forging and allowing the precision forging to cool in air to substantially ambient temperature; and

(h) machining less than 0.030 inch of material from the exterior functional surfaces of the cooled precision forging without subjecting the cooled precision forgoing to any heat treating operation prior to said machining.