A Novel Measurement Standard for Surface Roughness on Involute Gears

Abstract

Although manufacturers of coordinate measurement systems and gear measurement systems already provide instruments that enable an end-of-line-monitoring of the roughness properties of gears, the roughness measurement on gear flanks still lacks traceability with respect to the standardised SI-units. There is still a gap between well standardised roughness measurements on planar surfaces and gear measurements on involutes. This gap is bridged by a novel physical measurement standard (PMS), also referred to as material measure, for roughness measurements on involute gears that has been developed at the Physikalisch-Technische Bundesanstalt (PTB). The necessary transformations between the systems of roughness and gear measurements have been implemented. The measurement standard itself represents calibrated roughness values for the parameters Ra, Rz, Rq, Rk, Rpk and Rvk and Mr1 and Mr2. Furthermore, the PMS can be measured both with classic profilometers as well as gear measurement systems with integrated roughness probes.

Measurement Method for Geometric Parameters of Small Module Gears Based on Machine Vision

“…This step uses a standard block to calibrate the measurement system, then it can make the system K = L⁄L_0, and determine its ratio to 0. L denotes the measured computer image size and L_0 is the standard size of the block [14]. The size of the image is measured in pixels and the measured size of the measurement block is calculated in millimeter units.…”