The fascination of the automotive differential has led to the idea to build a second differential unit around a first center unit. Both units have the same axes around which they rotate with different speeds. The potential of double differentials as ultrahigh reduction speed reducers is significant. Only the tooth-count of the gears in the outer differential unit must be changed in order to achieve ratios between 5 and 80 without a noticeable change of the transmission size.
Gear noise is a common evil any gear manufacturer must live with. It is often low enough not to be a major problem but, at times, gear whining may appear and then, tracking the source and, especially, curing the ill can be tricky at best.
This article is the fourth installment in Gear Technology's series of excerpts from
Dr. Hermann J. Stadtfeld's book, Gleason Bevel Gear Technology. The first three
excerpts can be found in our June, July and August 2015 issues.
In the previous chapter, we demonstrated the development of a face-milled spiral bevel gearset. In this section, an analogue face-hobbed bevel gearset is derived.
