Title: Hardening process for crankshafts

Abstract: A hardening process for a crankshaft which includes subjecting the crankshaft to a first induction hardening process to produce a hardened layer of a substantial thickness at all bearing locations and at all transitional points between the crank pins, journal pins and crank webs. Subsequently tempering the hardened zones of the crankshaft at the transitional points to a hardness value permitting a subsequent alignment of the crankshaft. Subjecting the crankshaft to a further induction hardening process to provide a second hardened layer only at the bearing locations which second layer has a depth which is less than the depth of the first hardened layer. The thus processed crankshaft is then subject to an expansion process to eliminate internal stresses therein.

Do you think this is a good invention? Vote now:

Votes so far: For:(0) Against:(0)
Other info:

Inventors: Just, Karl (Immenstaad, DT)

Application Number: 634775
Filing Date: 1975-11-24
Publication_date: 1977-08-23
Assignee: Motoren- und Turbinen-Union Friedrichshafen GmbH (DT)
Primary Class(es): 148/572 148/639, 148/904
Other Classes:
US Patent Ref:

2213241	Sep, 1940	Denneen et al.	148/146.
3377214	Apr, 1968	Woodbridge et al.	148/146.

Other Refs:
Primary Examiner: Dean, R.
Assistant Examiner:
Attorney: Craig & Antonelli