Publication Date


Document Type


First Advisor

Gupta, Abhijit

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Mechanical Engineering


Reciprocating pumps; Hydraulic motors; Mechanical wear; Silicon nitride


Axial piston hydraulic pumps and motors can experience wear-related failure modes when operated under extreme conditions, such as with particulate contaminated oil, at high oil temperatures, or during cavitation conditions. A thin, monolithic silicon nitride (Si[sub 3]N[sub 4]) wear plate was developed for the interface between the slippers and wobbler to improve reliability and survivability under such conditions. The concept was applied to the hydraulics in a Sundstrand Integrated Drive Generator. The wear plate material was selected through experimental screening of four different grades of silicon nitride (Si[sub 3]N[sub 4]) and five different grades silicon carbide (SiC). Wear resistance and flexural strength were the two primary criteria used in the selection process. Finite element methods were used to perform stress analysis for both the Si[sub 3]N[sub 4] wear plate and wobbler body. Margins of safety, fatigue life, and critical flaw size of the ceramic are calculated. Application testing verified the structural integrity of the Si[sub 3]N[sub 3] wear plate and wobbler. Tremendous wear and contamination resistance of the Si[sub 3]N[sub 4] insert was also demonstrated under severe test conditions.


Includes bibliographical references (pages [57]-58).


viii, 75 pages




Northern Illinois University

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