Porous tungsten plugs provide even airflow for frictionless bearings used in air bearing supported gyros. The plugs have their outer cylindrical surface sealed by an electron beam process to ensure unidirectional airflow through their exit ends

Herz, W. H.

Kurtz, A. D.

Kurtz, R. A.

English

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,t1rs-/36 
February 1966	 Brief 66-10033 
NASA TECH BRIEF	
-I& 
	
c- . -	 ..	 .....	 ..- -..... 
NASA Tech Briefs are issued to summarize specific innovations derived from the U. S. space 
program and to encourage their commercial application. Copies are available to the public from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
	
IIT I.
	
IITITITI1T	 .IT IT:.TITTITIII------------ 	 ITTfTIT TTITTII 
Electron Beam Seals Outer Surfaces of Porous Bodies 
Electron Beam Gun
Porous 
Material
Optical	 - -  
Viewing 
System tiOn 
 
To	
________J	
Magnetic Lens 
Deflec 
oill
Electron Beam 
Welding 
Chamber  
Workpiece 
Controls to 
To	 move Workpiece 
Vacuum 
System
	
I
ensure unidirectional air flow through their exit ends. 
The plugs are used as the air passages in the air 
bearing seat body. 
How it's done: 
Tungsten powder is compacted into rod form by the 
application of pressure, cut into plugs and then sin-
tered and machined. Each plug is then placed in an 
electron beam welder and the beam is oscillated at an 
appropriate frequency as the workpiece is rotated and 
passed beneath the beam. The electron beam causes 
the high points of the tungsten surface to melt and 
(continued overleaf) 
The problem: 
To provide an even air flow for frictionless bearings 
used in air bearing supported gyros. Multiple passages 
in the bearing seat must be designed to precisely dif-
fuse the entering air and restrict its rate of flow. Any 
lateral flow rather than direct flow through the passage 
exits results in a nonuniform layer of air between 
bearing and seat and cannot be tolerated. - 
The solution: 
Porous tungsten plugs having their outer cylindri-
cal surface sealed by an electron beam process to 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19660000033 2020-03-11T17:33:48+00:00Z
	the movement of the workpiece is such that a solid
	 Patent status: 
	
skin surface approximately 0.001 inch thick is
	 Title to this invention has been waived under the 
achieved.	 provisions of the National Aeronautics and Space 
Notes:	 Act (42 U.S.C. 2457 (f)), to the Kulite Tungsten Corn-
	
I. In the process outlined, voltages of about 105 to 	 pany, 1040 Hoyt Avenue, Ridgefield, New Jersey. 
	
110 k and currents of about' 1.5 ma are used. 	 Source: Ronald A. Kurtz, Anthony D. Kurtz, and 
	
Workpieces are rotated at 20 rpm and linear move- 	 William H. Herz of Kulite Tungsten Company 
	
ment is at 1 inch per minute. Source to specimen	 under contract to Marshall Space 
distance of from 5 to 8 inches is satisfactory.	 Flight Center 
	
2. This invention would be useful in the areas of fluid 	 (MF5562)
and gas filters and metering devices. 
Brief 66-10033	 Category 03


Electron beam seals outer surfaces of porous bodies

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