ANALYSIS OF FRICTION TORQUE IN SIMPLE AND PRELOADED SPUR GEAR TRAINS
Abstract
The first part of this study develops the relation between the required drive torque and the load torque in a lightly loaded, single gear mesh, considering Coulomb friction between the sliding tooth surfaces. Bearing and windage losses are not considered. All of the load is assumed to be carried on a single pair of teeth, since for lightly loaded gears elastic deflections will be smaller than tooth-to-tooth errors, so that a single pair of teeth may carry the load regardless of the theoretical contact ratio. The use of 'efficiency' formulas given in the literature usually gives low values for starting torque requirements. The second part of the study extends the equations to a four- square gear train as representative of preloaded split gear trains, where friction losses are relatively greater than in simple trains. It is demonstrated that the maximum possible friction loss for a given foursquare gear train would occur when and if the two gear meshes simultaneously begin approach action. It is also demonstrated that the friction loss for a gear train using spring-loaded split gears cannot exceed values calculated on the assumption that one mesh begins approach action while the other mesh terminates recess action.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 22, 1965
- Accession Number
- AD0624591
Entities
People
- James W. Titus
Organizations
- United States Naval Research Laboratory