SOCIETY OFAUTOMOTIVE ENGINEERSJack T.Stevenson u.S.ArmyEngineerResearch &DevelopmentLaboratori esRequirements 650672IMilitaryHydraulic System Farm,Construction and IndustrialMachinery Meeting Milwaukee, Wis. September 13-16,1965Downloaded from SAE International by University of Wisconsin - Madison , Monday, September 10, 2018650672 Military Hydraulic System Requirements Jack T. Stevenson U. S. Army Engineer Research & Development Laboratories HYDRAULIC SYSTEMS applications on military construction equipment ar e not essentially different from commercial applications, but the manner in which they are purchased, used, maintained, and supported, and the fact that the re­ sponsibility of each is under a separate organization, requires a well planned program to make possible procurement of hydraulic systems with adequate performance, reliability, endurance, standardization, maintainability, and logistical support. In response, the hydraulic program overall objec­ tive is to standardize systems and components, establish minimum standards for acceptance, and coordinate with the user, maintenance, and supply organizations in an effort to meet the military hydraulic system requirements in the simplest, most practical and economic manner possible.This paper presents the overall hydraulic program being conducted at the Engineering Research and Development Laboratories. APPLICATION For purposes of this paper, only the open-center type, 2000psi syste m will be discussed, but the standardization theory herein is applicable to all systems. Military procurements of hydraulically controlled equip­ ment i n the past three years has inidcated that an open-cen­ ter, 2000 psi hydraulic system is well within the commercial state-of-the-art. To illustrate, in Fig. 1 is shown a rubber tired tractor connected to a scraper. In this application the NOTE: The views contained herein represent only those of th e author and have not been approved by the Dept. of the Army nor do they necessarily represent current Dept. of the Army policy. Fig. 1 - Rubber tired tractor connected to scraper ABSTRACT To meet the military hydraulic system requirements for construction equipment , the Engineer Research and Develop­ ment Laboratories has initiated a hydraulic program to de­ velop minimum standards of system and component accept­ ance through the media of performance specifications. The program will also establish a standardization of system types and o f component mounting and port configuration. Such standardization, including hoses, tubing, and couplings, is intended to simplify maintenance and logistical support of hydraulic systems. Downloaded from SAE International by University of Wisconsin - Madison , Monday, September 10, 20182 tractor dozer and scraper functions are all hydraulically ac - tuated, and actuation rates of each permit the use of a com­ mon pump. The steering on the tractor is powered by a double pump to provide satisfactory steering at both high and low speeds. In Fig. 2 the rough terrain fork lift truck has a more complex application of hydraulics. The fork raise and lower, tilt, extend and retract is actuated by one pump, the forks side-shift and the vehicle oscillation is ac­ tuated by another pump, and the steering system has two separate flow controlled pumps which independently power their related steering axles. The function dictates the application, but permits selec­ tion o f the system type. In both applications performance was the major influencing factor in the selection of the sys­ tem. PERFORMANCE Performance of the hydraulic system is based upon the user en d item requirements. Performance is usually the pre­ dominant factor in specifying minimum system requirements and, therefore, must be given due consideration. The most satisfactory method of defining performance in a system spe­ cification is to place practical limitations on the system in terms of fluid temperature, p