Hypoid ring/pinion. Is there a generally optimal rotation?

[fieldrator]

Taking the following image for example..

http://www.roymech.co.uk/images9/gear_bevel_5.gif

A low pinion hypoid drive. Most examples listed as "reversible".

If the primary rotation is intended for the ring gear to turn clockwise (facing the image above), does it make a difference if the pinion is "high" (intersecting the ring gear above center axis) or "low" (below the center axis as above).

Or does the geometry of hypoid gearing make such consideration irrelevant?

 

[MikeHalloran]

The transverse cross section of a hypoid gear tooth resembles that of a Buttress thread. Hypoids are 'reversible' enough to allow use of a reversing transmission, but not enough to allow use at full power for full life in the 'reverse' direction.

WRT to the set shown, if you were to rotate/reposition the pinion 180 degrees around the ring gear center, so the pinion enters from the left, above the ring gear, and retain the usual, proper rotation, the set might work for a while. ... but ... These gearsets are normally run with the pinion submerged in lubricant, and the pinion housing casting often has channels shaped to help lubricate the pinion bearings, redirecting the circumferential flow induced by the ring gear.

If you operate with the pinion 'high', and don't provide a substantial flow of lubricant for the pinion bearings, they will die young, destroying the gearset in turn.


Mike Halloran
Pembroke Pines, FL, USA

 

[fieldrator]

Thank you very much for that. Just to clarify, if I might...
May I assume then that the ring above is intended primarily to run counterclockwise... and the lower clockwise?

 

[MikeHalloran]

That's how I would classify them.


Mike Halloran
Pembroke Pines, FL, USA