Gimbaled spinmotor, gyro assembly, and gyro test results for gas bearing gyroscopes with high G and sterilization capabilit

Erickson, G. J.

English

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J E T  P R O P U L S I O N  L A B O R A T O R Y  
C A L I F O R N I A  I N S T I T U T E  O F  T E C H N O L O G Y  
P A  S A D  E N  A ,  C A L I  F O R  N I A 
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. : i 
THE DESIGN AND BUILD OF A G A S  BEARING GYROSCOPE POSSESSING 
HIGH G AND STERILIZATION CAPABILITY AND UTILIZING A LOW 
POWER GAS BEARING SPINMOTOR AND HIGH FREQUENCY PUMP 
- 
20660 -QR5 
Fifth Quarterly P r o g r e s s  Report 
for period 
1 January 1968 - 31 March 1968 
Prepared  for 
J e t  Propulsion Laboratory 
California Institute of Technology 
Contract No. 951559 
S po ns o red by 
The National Aeronautics and Space Agency 
. under Contract No. NAS7-100 
Honeywell Inc. . 
Aeroepace Division 
Minneapolis, Minnefiot a 
. 
THE DESIGN AND BUILD OF A GAS BEARING GYROSCOPE POSSESSING 
HIGH G AND STERILIZATION CAPABILITY AND UTILIZING A LOW 
POWER GAS BEARING SPINMOTOR AND HIGH FREQUENCY P U M P  
Contract No. 951559 
Fifth Quarterly P rogres s  Report 
for period 
1 January 1968 - 3 1  March 1968 
This work w a s  performed for the Je t  Propulsion Laboratory, 
California Institute of Technology, sponsored by the National 
Aeronautics and Space Agency under Contract NAS7- 100. 
P repa red  by: 4,- 
E r i ck s on 
Pr inyipal Development 
Engineer 
Approved by:. , , 
S. J. Korzknowski 
Project  Engineer 
R.G.  Baldwin 
Section Head 
T . W .  Garvey I 
P r o g r a m  Administrator 
Honeywell Tnc. 
Aerospace Division 
. Minneapolis, Minnesota 
a 
This repor t  was prepared as an  account of Government-sponsored work. 
Neither the United States, nor the National Aeronautics and Space Admin- 
. is t ra t ion (NASA), nor any person acting on behalf of NASA: 
a. Makes warranty of representation, expressed or implied with 
respec t  to the accuracy, completeness, or usefulness of the 
information contained in  this  report ,  o r  that the use of any 
information, apparatus, method o r  process  disclosed in this 
repor t  may not infringe privately owned rights;  o r  
b. Assumed any liabilities with respect  to  the use of, o r  for 
damages result ing f rom the use of any disclosed in  this  repor t .  
1 1  A s  used above, 
o r  contractor of NASA, o r  employee of such contractor,  to  the extent 
that such employees o r  contractor of NASA, or  employee of such con- 
person acting on behalf of NASA" includes any employee 
b t r ac to r  prepares ,  disseminates, or provides access  to, any information 
pursuant to  his employment with such contractor. 
, 
Seques ts  for copies of this report  should be re fer red  to: 
National Aeronautics and Space Administration 
Office of Scientific and Technical Information 
Washington, D. D. 
Attention: AFSS-A 
, 
2066 0-QR5 
3 
- .  iii .- 
I 
ABSTRACT 
The fi€th quar te r  work on the design, build, and tes t  of a gas  bearing 
. gyroscope possessing high g and steri l ization capability and utilizing 
a low-power gas  bearing spinmotor and high-frequency pump, has  
produced a gimbaled spinmotor, gyro assembly and f i r s t  gyro tes t  
resu l t s .  In parallel ,  a concentrated investigation into moisture, 
organic vapor, and particulate contahination is in process .  
20660-QR5 
- iv - 
SECTION I 
. SECTION11 
SECTION 111 
CONTENTS 
Page 
SUMMARY 
P r o g r e s s  (Fifth Quarter)  
Problems (Fifth Quarter)  
Future Work  (Sixth Quar te r )  
DISCUSSION 
Lockup Investigation 
Moisture Lockup 
Organic Vapor and Particulate Contami- 
nation Lockup 
Infrared Analysis 
Ultraviolet - Fluorescence Analysis 
Mass Spectrometer Analysis 
Gas Chromatograph Analysis 
Thermal  Analysis T e s t s  
Stat o r  Canning 
Spinmotor Shock and Vibration Testing 
Gyro Build and Test 
Gimbal Assembly 
Gyro Build 
Gyro Tes t  
SCHEDULE 
1 
1 
1 
. 2  
3 
3 
3 
5 
5 
6 
6 
6 
1 0  
1 0  
12  
12  
1 2  
1 3  
1 3  
1 4  
2066C-QR5 
Figure 
1 
2 
3 
- v -  
ILLUSTRATIONS 
Sample Infrared Map 
GG159E/GG334S Gimbal G a s  Sampling Fixture 
GG159E G a s  Bearing Spinmotor 
TABLES 
Moisture Lockup Sensitivity of Optimized 
As sym et r ic a1 Journal De sign 
Ultraviolet - Fluorescence of Materials Used i n  
the GG159E/GG334S 
Summary of Gyro Test  Results 
. 
206 6 0 -QR5 
Page 
7 
9 
11 
4 
8 
13  
‘ 0  
- 1 -  
SECTION I 
SUMMA RY 
The purpose of this contract  i s  to build a gas  bearing gyroscope pos- 
sessing high g- and sterilization capability utilizing a low -power gas 
bearing spinmotor and a high-frequency piezoelectric pump. 
PROGRESS (FIFTH QUARTER) 
0 Coordination meeting at JPL and implementation of bi-weekly pro-  
g r e s s  reports  
0 
0 Gimbal assembly 
Test  of moisture anti-lockup motor geometry 
0 Pretesting of high-frequency pump 
0 Prel iminary gyro testing 
e Detailed investigation of moisture, organic vapor, and particulate 
contamination 
PROBLEMS (FIFTH QUARTER) 
0 The spinmotor start ing voltage has increased to  a marginal 
value 
20660-QR5 
7 
@ FUTURE WORK (SIXTH QUARTER) 
- 2 -  
0 Continuing gyro test 
0 Gyro teardown and motor  repa i r  (high s tar t ing voltage) 
. 0 Gyro rebuild and start of final gyro testing 
0 Completion of contamination investigation 
. 
20660-QR5 
lo 
- 3 -  
SECTION I1 
DISCUSSION 
LOCKUP INVESTIGATION 
The lockup problem is being investigated. 
moisture-induced lockup but a lso organic vapor and particulate con- 
tamination-induced lockup. 
This effort includes not only 
Moisture Lockup 
The moisture  lockup problem was f i r s t  discussed in the fourth quarter ly  
p r o g r e s s  report  on contract 951529 (GG334S) which uses  the same  motor as 
the GG159E developed here  under contract 951559. 
ability to  r e s t a r t  the motor when it has  been stopped after continuous running 
for periods between 10 and 100 hours. 
into the gimbal atmosphere and then is pumped into the gas bearing where it 
condenses.  
motor slows down and the pa r t s  approach each other .  
in is indicated by an abrupt stopping of the rotor  on rundown. 
be r e s t a r t ed  i f  sufficient t ime (several  days) is allowed for the water  to 
evaporate;  and the s tar t ing voltages quickly r e tu rn  to original values with a 
few quick s t a r t s  and stops.  
the >ycle. 
The problem is an in- 
Moisture in the gimbal pa r t s  evaporates 
This  condensation allows the rotor  to wring to the shaft when the 
The point of wringing 
The motor can 
Running the motor for a few hours will repeat 
Drying the gas  with a molecular sieve-type drying agent, combined with piece 
p a r t  drying before assembly, extends the life of this motor but will riot p re-  
vent the lockup f r o m  eventually occurring. 
bear ing patterning is nccessary  to accomplish the required life. 
It has been shown that revised 
f 
- 4 -  
. Moisture lockup can be prevented by using patterns which pump gas  through 
t h e  bearing assembly as opposed to the usual configuration where each 
thrust  bearing develops equal pressure at the ends of the journal bearing 
and crea tes  a high-pressure,  z e r o  flow condition. 
the assembly of thrust  and journal bearings, the moisture can be car r ied  
away faster  than i t  can condense. 
By pumping gas  through 
Testing has  shown the optimum pattern for preventing moisture locku'p is 
. the assymetr ical  journal pattern. In this  approach, one of the two journal 
patterns is made longer than the other. 
differential along the axial length of the journal bearing resulting in axial 
gas  flow. 
This assymetry  creates  a p re s su re  
The assymetr ical  journal motor was tested under adverse moisture con- 
ditions with excellent resul ts .  After cleaning and assembly, the motor was 
mounted in a smal l  air tight chamber and i t s  performance monitored at the 
ambient relative humidity (RH) condition of 40 percent.  Then, successive 
incremental  amounts of water  were added to bring the RH to 90 percent. 
moisture  lockup was  observed. 
No 
Table 1 summar izes  the resu l t s .  
Table 1. Moisture Lockup Sensitivity of Optimized 
Assymetrical Journal Design 
Relative Humidity $ Running Hours Motor Per for rn ance 
40 1. 0 No Lockup 
50 3 . 0  No Lockup 
60 2.0 No Lockup 
70 2.0 No Lockup 
80 2 . 0  No Lockup 
90 2. 0 No Lockup 
2066 0-QR5 
1 - 5 -  
This testing verifies that the assymetrical  journal pattern wi l l  successfully 
~ .a 
solve the moisture lockup problem, However, experience on another gas  
bearing program shows there  is also a possibility of organic vapor o r  par-  
ticulate contamination causing lockup. Obviously, these mechanisms differ 
f rom the moisture mechanism, but the resul t  is the same.  
paral le l  investigation program has been launched to pinpoint and remove any 
possible sources  o€ contamination. 
Accordingly a 
Organic Vapor and Particulate Contamination Lockup 
A s e r i e s  of analytical tools have been and a r e  being developed to aid in pin- 
pointing sources  of contamination. With the source identified, design 
changes can be implemented to prevent the possibility of contamination 
occurring. These analytical tools a r e  discussed below. 
0 Inf ra red  Analysis. - -  A total of 14 organic mater ia ls  a r e  being u s e d  (or could 
be used )  in the GG159EIGG334S gimbal assernb)y. These a r e  listed below. 
6020Q, CaC03 filled amine hardened 
6020Q, fluorescent dye 792 1 
6293 F natural  CaCog f i l led amine hardened 
6293 F black dye 
6293 G unfilled, amine, with diisocyanate and tetrasulfide 
6293 H, unfilled, amine 
6293 J, anhydride, Ti02 fi l ler  
6293 N natural  7274 ckramic fill, amine hardened 
6293 N black dye 
738 1 Bondmaster. Amine with isocyanate 
7556 Eccobond aliphatic amine s i lver  epoxy 
7 2 0 0 He r e s it e ,  phe no 1 i c 
7553 Epoxolite 293- 11. Anhydride 
7997-01 DK-4. Anhydride 
I 
- 6 -  
Infra  red maps ( see  Figure 1 for  sample) have been prepared for all 14 
mater ia ls .  With these maps, it should be a simple matter ,  should con- 
tamination occur,  to compare appropriate finger prints and identify the 
contaminant. 
Ultraviolet  - FluDrescence Analysis - - Since gas  bearing contamination is 
sometimes found in  too smal l  a quantity for infrared analysis, ultraviolet 
fluroescence samples  were also prepared to  form a standard for comparative 
checks. 
powder, have been assembled into a compact visual aid comparison system. 
This system will permit  visual correlation of the contaminant with the pre-  
viously assembled standard. 
The previously mentioned 14 materials ,  plus "Sepkol' cleaning 
Table 2 l i s t s  the resu l t s .  
Mass Spectrometer Analysis - -  Mass spectrometer  analysis will be used to 
sample gimbal f i l l  gas  for moisture content and organic vapor constituents. 
A fixture has been designed a n d  built to permit direct  gimbal gas sampling 
a s  shown in Figure 2 .  
with an "0" ring pr imary sea l .  A wheel puller device is  used to extract  the 
fill plug permitting the gimbal gas  to enter  the mass spectrometer chamber.  
The same  fixture can also be used for gas  chromatography cross  checks. 
The gimbal is  solidly clamped between the end nests 
Gas Chromatograph Analysis - -  Five mater ia ls  have been selected on the 
basis of quantity and proximity to the motors for outgassing and dewpoint 
t e s t s .  These mater ia ls  a r e  listed below. 
MS6293F natural color, CaC03 filled, amine hardened 
(Stator Impregnant) 
MS6293G unfilled amine hardened with Diisocyanate and t e t r a -  
sulfide (Epoxy Adhesive) 
MS6293N black dyed, ceramic filled, amine hardened (Stator 
Coating) 
MS738 1A Bondmaster, amine hardened epoxy (Stator Lamination 
MS7556A Eccobond Aliphatic amine hardened silver filled epoxy 
Adhesive) 
(Electrically conductive adhesive) 
20660-QR5 * 
- 7 -  
70 
60 
z 
cn 0 
L" 5 0 .  
z 
cn z 
k 
5 40 w 
0 
p: 
w a 
30 
20 
10 
r 
. 
' 
. 
I 
I 
I 
I 
I 
I 
I 
I 
I 
I 
I 
I 
I 
I 
1 
28 24 20 20 18 16 
RECIPRICAL OF WAVELENGTH (Ch4-l x 100) 
Figure 1, Sample Infrared Map 
20660-QR5 
I 3 
- 8 -  
Table 2 .  Ultraviolet - Fluorescence of Mater ia ls  
Used in the GG159E/GG334S 
Mat e r ial * Samples in Solid 
or Bar Form 
Sample s Ground 
Into Powder 
6020Q (CAC03 Filled) 
6020Q, Fluorsecent Dye 
6243F Natural (CAC03 
6293F Black Dye 
62 93G (Unfilled) 
62  93H (Unfilled) 
62  93 J (Ti02 Fi l led) .  
62 93N Natural  (Silicate 
Filled) 
Fil led) 
6293N Black Dye 
73 81 * Bondmaster 
7556 Eccoborid 
7200 Heresi te  
7553 Epoxilite 293-11 
7997-01 DK 4 
Sepko Powder 
Mildly Fluor  e scent  
F lu  or e s c e nt 
Mildly Fluorescent  
Nonfluore s cent 
Mildly Fluorescent 
Mildly Fluorescent  
Nonfluorescent 
Mildly Fluorescent 
Nonfluorescent 
Fluorescent 
Nonf luo r e s cent 
Nonfluor e s cent 
Nonfluore s cent 
Nonfluor e s cent 
- ~. 
Mildly Fluorescent 
Fluore scent 
Mildly Fluorescent 
Nonfluorescent 
Mildly Fluorescent 
Mildly Fluorescent 
Nonfluore scent 
Mildly Fluorescent 
Nonfluore scent 
F1 u o r  e s cent 
Nonfluor e scent 
Nonfluore s cent 
Nonfluorcscent 
Nonf luore s cent 
Mildly Fluorescent 
2 0660 -QR5 
- 9 -  
COMPRESSION SEAL BOLSTER 
PLATE 
GIMBAL COMPRESSION SEAL 
PLATE 
GIMBAL NESl-UPPER 
GIMBAL NEST-LOWER 
Figure 2. GG159EIGG334S Gimba l  G a s  Sampl ing  Fixture 
20660-QR5 
- 10 - 
Thermal  Analysis Tests - -  Thermal behavior of the 14 organic materials 
used for the above UV-fluorescence tests will a lso be studied under a hot 
stage microscope capable of 350°C. 
m o r e  rapid future identification of contaminant mater ia ls .  
Data from this analysis will enable 
STATOR CANNING 
Design layout work on the canned s ta tor  w a s  completed and experimental  
Units built and tested.  
formed t o  the exact contour of the s ta tor  end turns .  
bonded t o  the slot bridge and stator hub to totally enclose the s ta tor  in metal 
except for  the bondlines. 
moisture  contamination exuding from the s ta tor .  Also, consideration was 
given to a solid l iner for the laminated P-6 hysteresis  r ing as also shown in  
F igure  3 .  
binations as shown below. 
Figure 3 shows the basic concept. Two end cans a r e  
These cans a r e  then 
This approach should minimize organic vapor o r  
A series of magnetics t e s t s  were  conducted with various com- 
1. Canned s ta tor  - standard H-ring ro tor  
air gap = 0.002" Power 3 .  0 watts 
Sync Margin 7 . 0  volts 
Start Margin 6 .  0 volts 
air gap = 0.004" Power 
Sync Margin 
Start Margin 
2. Canned s ta tor  and lined H-ring 
air gap = .o. 001.'' Power 
Sync Margin 
Start Margin 
air gap = 0.002" Power 
Sync Margin 
Start  Margin 
air gap = 0.004" Power 
Sync Margin 
Start Margin 
4 .  2 watts 
6 . 0  volts 
6 . 0  volts 
3.  6 watts 
2 . 0  volts 
4 .  5 volts 
3 . 9  watts 
3 .  0 volts 
5 .0  volts 
4 . 0  watts 
4 . 0  volts 
6 . 0  volts 
206 6 0 - QR 5 
- 11 - 
SLOT RING BRIDGE 
(HYPE R N I K) STERESIS RING LINER 
HY STE RE SI S RING, LAM I NATE D 
THRUST PLATE (2) 
HY D R 0 DY MA MI C 
THRUST BEARING (2) 
HYDRODYNAMIC 
JOURNAL BEARING 
MOMENTUM RING 1 
(TUNGSTEN) 
* 
Figure 3. GG159E Gas Bearing Spinmotor 
2osso-QR 5 
TEE L) 
- 1 2 -  
It is evident f r o m  t h e s e  t e s t s  tha t  adding the s lo t  b r idge  and s t a t o r  c a n s  and 
rcclucing the  a i r  g a p  t o  0 .  002 inch p roduces  a m o t o r  with r e a s o n a b l e  s y n c  
and s t a r t  m a r g i n s  with accep tab le  power consumpt ion .  
r i n g  is not d e s i r a b l e  f r o m  a power  standpoint.  
be fab r i ca t ed  with a s lo t  bi'idge and s t a t o r  c a n s .  
Lining the  h y s t e r e s i s  
' 0  
T h e  GG159E sp inmoto r  wi l l  
SPINMOTOR SHOCK AND VIBRATION TESTING 
Shock t e s t i n g  of t h e  u n s y m m e t r i c a l  journa l  p a t t e r n  m o t o r  w a s  success fu l ly  
comple ted  with t h e  appl ica t ion  of five 200 g, 1. 5 mi l l i second s h o c k s  i n  each  
a x i s .  
greater than  200 g's. 
T h e  t h r e e  - p a t t e r n  t h r u s t  p la tes  i n c r e a s e d  t h e  t h r u s t  capabili ty to 
8 
S u c c e s s f u l  v ibra t ion  t e s t i n g  w a s  also accompl i shed  wi th  t h e  m o t o r  withstanding 
t h e  r a n d o m  no i se  a n d ' r a n d o m  noise  plus s i n e  wave p e r  JPL s p e c  N 30250B 
a m e n d m e n t  2 .  
a 
GYRO BUILD AND TEST 
G i m b a l  A s s e m b l v  
Y 
A f t e r  t h e  s u c c e s s f u l  shock  and v ibra t ion  tes t ing ,  t h e  s p i n m o t o r  w a s  s e a l e d  
into a g imba l  and p laced  o n  extended run in .  
vo l tage  w a s  noted and s o m e  out of s p e c  s t a r t i n g  vol tage  r e a d i n g s  w e r e  
ob ta ined .  
ind ica t ion  of t he  c l a s s i c  m o i s t u r e  lockup w a s  ev ident .  
v a r i a b i l i t y  i s  a t t r i bu ted  to o r g a p i c  vapor  o r  pa r t i cu la t e  contaminat ion .  
It w a s  dec ided  to  p r o c e e d  with t h e  g y r o  build to d e t e r m i n e  whe the r  any 
p r o b l e m s  would r e s u l t  from the  in tegra t ion  of the  p i ezo  pump to  the  g y r o .  
Some  va r i ab i l i t y  in  s t a r t i n g  
However ,  t h e  m o t o r  w a s  still o p e r a b l e  after 480 h o u r s  and no  
S ta r t ing  voltage 
2066 0-QR5 
- 1 3  - 
Gyro Build'? 
High-frequency pump operation was pre-tested p r io r  to final sealoff. 
levels due to pump on - pump off were l e s s  than the threshold of the tes t  of 
Torque 
~ 0. l " /hr .  
Gyro Tes t  
After functional tes t s  on the unsealed version were  conipleted, the gyro w a s  
sealed and preliminary t e s t s  were  performed. Initial t e s t s  verify the piezo 
pump reaction torques to  be l e s s  th'an 0. l " /hr  as was  suggested by the qn- 
sealed unit testing. Random drift was good. P rope r  suspension operation 
has been verified by good null repeatability performance ( l e s s  than 0. O l o / h r ) .  
Pre l iminary  testjng on the bellows capacity indicates a l a rge r  bellows w i l l  
be required.  Table 
3 summar izes  gyro tes t  data to  date. Vibration, shock, and steri l ization t e s t s  
t e s t s  a r e  planned for the mar  future. 
cipated t o  cor rec t  the marginal spinmotor start ing voltage and incorporate the 
canned s t a to r .  
Additional data is required to  put this in  perspective. 
A complete rebuild of the gyro is anti- 
Table 3 .  Summary of Gyro Test Results 
I tem Value Contract Req . 
High freq.  pump < 0. l o / h r  0. 25"/hr 
. .  reaction torque 
Random drift OAV < 0.008"/hr 0.008"/hr 
I A V  < 0.015"/hr 0 . 0  15"/hr 
Null Repeatability < O.Ol"/hr - 
c 
*: 
Gyro build proceeded with no difficulty. 
20660-QR5 
- 14 - 
20660-QR5 
SECTION I11 
S C HE DU LE 
The present  gyro tes t  will continue until mid April.  
rebuild will be accomplished by ea r ly  June. 
and shipped by 9 September 1968. 
Teardown and 
The gyro will be tested 
. 
1 
\ 


The design and build of a gas bearing gyroscope possessing high G and sterilization capability and utilizing a low power gas bearing spinmotor and high frequency pump Quarterly progress report, 1 Jan. - 31 Mar. 1968

The design and build of a gas bearing gyroscope possessing high G and sterilization capability and utilizing a low power gas bearing spinmotor and high frequency pump Quarterly progress report, 1 Jan. - 31 Mar. 1968

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