It is said that “The squeaky wheel
gets the grease.” Ok, but what about gear noise? We talked to three experts with
considerable knowledge and experience
in this area.
Design innovation, superior engineering properties, high
end-market visibility and sustainability distinguish the winners
of the 2011 Design Excellence awards, the annual powder metallurgy (PM) design competition sponsored by the Metal Powder Industries Federation.
In the majority of spiral bevel gears, spherical crowning is used. The contact pattern is set to the center of the active tooth flank and the extent of the crowning is determined by experience. Feedback from service, as well as from full-torque bench tests of complete gear drives, has shown that this conventional design practice leads to loaded contact patterns, which are rarely optimal in location and extent. Oversized reliefs lead to small contact area, increased stresses and noise, whereas undersized reliefs result in an overly sensitive tooth contact.
Gears with an asymmetric involute gear tooth form were analyzed to determine their bending and contact stresses
relative to symmetric involute gear tooth designs, which are representative of helicopter main-drive gears.
We talked energy efficiency with some
major players in the lubricants industry—
but with a focus on their products’
impact regarding energy efficiency of
gears and gearboxes in wind turbines.
The objective of this study was to investigate the limits concerning possible reduction of lubricant quantity in gears that could be tolerated without detrimental effects on their load carrying capacity.