Coast-Down Time as a Mechanical Condition Indicator.

Abstract

This initial report presents the development of a theoretical expression, and input for that expression, to predict the behavior of vertically mounted electric motors during coast-down. The coast-down behavior of four motors, equipped with grease-lubricated deep-groove ball bearings and operated at steady state under design conditions, is studied. The coast-down time (speed/time curve) is predictable by expression the torque (M) on the rotor as a function of the speed (N) of the rotor in a quadratic of the form M = A + BN + CN2. It is demonstrated that the predictive capability developed herein can be used effectively to determine whether a motor is being operated under the desired design conditions. More experimental data will be obtained to confirm or refine the predictive technique. Mechanical problems will be introduced into the motor in an attempt to determine the effect on the coast-down curve. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1976
Accession Number
ADA020154

Entities

People

  • Robert J. Craig
  • Thomas L. Daugherty

Tags

DTIC Thesaurus Topics

  • Ball Bearings
  • Bearings
  • Electric Motors
  • Experimental Data
  • Motors
  • Steady State

Readers

  • Computational Modeling and Simulation
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).