Item 1149
OTHER: Mechanical -
Gear - PlanetaryArticles on Planetary Gears from Gear Technology on Internet
847 437 6604 Fax Jennefer(These can be ordered - see Internet page)
"KHV Planetary Gearing --Part I." Yu, Nov/Dec 1987. ORDERED - Of no value
"KHV Planetary Gearing -- Part II." Yu, Jan/Feb 1988. ORDERED - Of no value
"Synthesis of Compound Planetary Gear Trains." Bagci, July/Aug 1990.
"Tooth Strength Study of Spur Planet Gears." Drago & Uppaluri, Sept/Oct 1986.
AGMA standard 6023-A88 is a complete design guide for planetary and epicyclic gear drives, including a good method for calculation ratios of complex arrangements. Highly recommended for this and the discussion of load sharing between planets, sizing components and thermal capacity.
Generally 14 1/2 degree compared to 20 deg pressure angles
14 1/2 degree PAs will have:
Higher contact ratio
Lower Bending Strength
Higher Shear Strength
More undercut
Lower bearing stresses and separation loads
20 degree PA will have:
Lower contact ratios
Higher Bending Strenth
Lower Shear Strenght
Less Undercut
Higher Bearing stress and separation loads
Most people are worried about Bending Strength in their designs - hence use 20 deg PA as a starting point.
Where are 14 1/2 deg PA an advantage?
- worm drives where the primary failure mode is augering of the worm thru the gear - esp if the gear is plastic
- designs that are challenging to achieve a contact ratio of greater than 1
- designs where bearing life is marginal
Outside Helicopter
See:
SynchroLite & UniCopter
xxx
xxx
FORM: PT - Secondary
Web Pages:
http://www.hexagon.de/zar1_e.htm
GearCad ~ Free demo download of GearSoft Design
SE/Examine Planetary Gear Equations
Introduction Page | SynchroLite Home Page | Electrotor Home Page | UniCopter Home Page | Nemesis Home Page | AeroVantage Home Page:
Last Revised: November 28, 2009