Method for determining a torsional structure in the surface roughness of a finished shaft journal

US6067720A · kind A · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Robert Heilbronner · Backnang, DE
• Norbert Rau · Ober-Ramstadt, DE
• Michael Seibold · Schwäbisch Gmünd, DE

Key dates

• Filing date: Sep 14, 1998
• Grant date: May 30, 2000
• Expiry date: Sep 14, 2018

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B5/285
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for determining a torsional structure in the surface roughness of a finished shaft journal includes making a plurality of axial scores on a circumferential strip of the shaft journal, with a high axial measurement point density at different but exactly known circumferential positions as well as with exactly known axial positions. The individual local roughness profiles are printed out in a close sequence with respect to one another corresponding to their positions. The measurement charts are raised or elongated in the radial and axial directions and upset in the circumferential direction. Thus, a topography with multidimensional affinity showing the microstructure of the surface in three dimensions in a diagonal view is obtained. An autocorrelation function is formed from this topography, stochastic elements are eliminated, and a surface topography is obtained that essentially contains only the periodic elements. From this surface topography, the characteristics of the torsional structure such as the angle of twist, period length, pitch, torsional slope, and the like can be determined.