Chapter 2, Continued
In the previous sections, development of conjugate, face milled as well as face hobbed bevel gearsets - including the application of profile and length crowning - was demonstrated. It was mentioned during that demonstration that in order to optimize the common surface area, where pinion and gear flanks have meshing contact (common flank working area), a profile shift must be introduced. This concluding section of chapter 2 explains the principle of profile shift; i.e. - how it is applied to bevel and hypoid
gears and then expands on profile side shift, and the frequently used root angle correction which - from its gear theoretical
understanding - is a variable profile shift that changes the shift factor along the face width. The end of this section elaborates on
five different possibilities to tilt the face cutter head relative to the generating gear, in order to achieve interesting effects on the
bevel gear flank form. This installment concludes chapter 2 of the Bevel Gear Technology book that lays the foundation of the following
chapters, some of which also will be covered in this series.
In order to properly select a grease for a particular application, a sound knowledge of the influence of different grease components and operating conditions on the lubrication supply mechanism and on different failure modes is of great benefit.
I would appreciate if you could assist with a gear failure (occurring)
after just seven weeks in service, post installation. This driving gear
wheel has been installed in a medium-speed engine with backlash
present at four different positions; with additional backlash checked on
the mating surfaces. All backlash was found within (OEM)-recommended values. Please note included photos - it seems that the crack has started at the root fillet. Any comments would be appreciated.