Design and development of double flank roll tester for cylindrical gears

Abstract

Gears are one of the most commonly used devices for both engineering and nonengineering applications offering an elegant solution to the problem of effective power and/or motion transmission. Modern gear drive design must provide quiet and reliable performance at high power, which can only be achieved by using gears which have accurate geometry like of Involute helicoid system. Metrology or inspection of gears can be divided into two subareas functional testing and analytical testing. Analytical testing of a gear determines different parameters describing its microgeometry such parameters describing form of its teeth (i.e. profile and lead), parameters describing location of its teeth (i.e. pitch and runout), and parameters describing topology of its teeth. It does not use any master or reference gear. Functional testing of gears is qualitative test which determines whether the manufactured gear will have functional performance as intended or not i.e. it can be considered as an inspection by attributes When two gears are in mesh with each other, any errors in tooth form, pitch and concentricity of pitch line causes variation in their center distance. According to method of contact between the rolling gears, functional testing can either be performed as single flank roll testing or double flank roll testing. Accordingly they provide different information. Single flank roll testing provides information about tooth-to-tooth transmission error, profile conjugacy (in terms of total transmission error), cumulative pitch error (or variation), adjacent pitch error, and effective profile error. Double flank roll testing provides information about tooth-to-tooth composite error, total composite error, radial runout and variation in the centre distance.. In the present work, analysis and comparison between total composite error and radial runout of the spur gear pairs finished by abrasive flow finishing (AFF) and pulsed electrochemical honing (PECH) processes and the near net-shape manufactured gear pairs by wire electric discharge machining (WEDM) process. It has been observed from the results that the Abrasive Flow Finishing of gears is more effective than Pulsed electrochemical honing of gears.