Influence of the DIN 3962 Quality Class on the Efficiency in Honed Powder Metal and Wrought Steel Gears

Abstract

To increase the efficiency of a gearbox, research on gear mesh loss is of importance. Britton et al. concluded that the surface finishing method affects the gear mesh efficiency. The efficiency benefits of superfinishing a surface and reducing the surface roughness have been reported by Kahraman. A novel method for calculating the bearing loss torque was proposed by Tu et al. Andersson et al. found that the efficiency can vary between 2 and 5% during repeated efficiency tests due to variations in the assembly process. This work investigates how the honing surface finishing process and DIN 3962 quality class affect the gear mesh efficiency by performing tests in an FZG back-to-back test rig. Two materials, a powder metal and a wrought steel, were tested. All gears were finished using a honing process and sorted according the measured quality class. Powder metal gears of class 6, 7, 8, and !9 and wrought steel gears of class 6, 7, and !9 were tested. The efficiency were calculated from measuring the torque required to maintain a constant velocity of the FZG test rig. The results from the efficiency tests showed no significant difference in efficiency between the wrought steel and powder metal steel gears. In addition, no obvious correlation between the DIN 3962 quality class and the gear mesh efficiency could be found. When examining the wrought steel material it was found that the reproducibility of the efficiency was comparable to the assembly error of the test rig, despite the variation in quality class.

The investigation of the effect of operating conditions in gearboxes on efficiency

“…Apart from this test rig, specially designed test setups have also been encountered. 3,17,25,[27][28][29][30] In the view of these information, the experimental setup used in this study was designed and constructed.…”

Reducing scrapping of gears by assessment of tip contact threshold torque

“…Gear set power loss is yet another aspect to consider. This was done by Bergstedt et al 18 , where the efficiency was studied for FZG C belonging to different tolerance classes. Measurements were made on both wrought steel and powder metal.…”