POWER STEERING FAILURE STUDY. VOLUME I. EXECUTIVE SUMMARY

This report describes the feasibility of modifying power steering systems to prevent excessive steering effort resulting from a power steering failure. Field test data are presented which provide the basis for requirements for maximum steering forces, minimum flow rates, and horsepower as a function of vehicle size, maximum allowable delay time (transient time prior to forces exceeding limits), and minimum operation time. These tests were made using an instrumented, variable power steering test car driven by three naive subjects on a closed test course. A power steering pump bypass was tested as one possible means of reducing steering forces due to a failed system, but this method proved totally unsuccessful for all conditions. A tradeoff table describing other candidate implementation schemes versus their estimated cost and capability (elimination of specific power steering failure modes) is presented in conclusion. This shows the most cost effective solution to be an auxiliary electric motor coupled to the existing power steering pump through two one-way clutches.

• Supplemental Notes:
  • See also Volume 2, PB-275 627.
• Corporate Authors:

  Systems Technology, Incorporated

  13766 South Hawthorne Boulevard
  Hawthorne, CA  United States  90250

  National Highway Traffic Safety Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Klein, R H
  • Szostak, H T
  • Ashkenas, I L
• Publication Date: 1978-1

Media Info

• Pagination: 28 p.

Subject/Index Terms

• TRT Terms: Automobiles; Clutches; Cost effectiveness; Failure; Field tests; Flow; Force; Horsepower; Hydraulic equipment; Mechanical failure; Motors; Power steering; Pumps; Servomechanisms; Size; Steering; Traffic delays; Vehicle characteristics
• Uncontrolled Terms: Flow rate
• Old TRIS Terms: Hydraulic power pumps; Hydraulic servomechanisms; Modification kits
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00169749
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: DOT-HS-803-032 Final Rpt., STI-TR-1083-1-Vol-1
• Contract Numbers: DOT-HS-6-01428
• Files: NTIS, TRIS, USDOT
• Created Date: Mar 14 1978 12:00AM