Abstract

NASA is leading the design and development of a next-generation CO2 removal system, the four bed carbon dioxide scrubber (4BCO2), and intends to use the International Space Station (ISS) as its testbed. A key component of the system is the blower that provides the airflow through the CO2 sorbent beds. To improve performance and reliability, magnetic levitation (magnetic bearings) will be used in lieu of more conventional bearings (e.g., ball bearings or air bearings) to improve resistance to contaminants and enable extensibility with regards to blower speed, pressure rise and mass flow rate. The blower will pull air from the ISS through an adsorbing desiccant bed and push it through a CO2 sorbent bed and desorbing desiccant bed. The 4BCO2 blower features an overhung permanent magnet motor, a centrally located five-axis, active magnetic bearing system, backup bearings, and an overhung centrifugal impeller in a very compact package. Magnetic bearings are a natural choice for this application due to low power consumption, low transmitted vibration and oil free operation. This article describes the design considerations and design selections for the blower system with a focus on the magnetic bearings. Magnetic FEA of the actuator/sensor system, rotordynamics/controls analysis, and backup bearing drop simulations are discussed in detail. It is expected that the successful implementation of magnetic bearings for this space application will encourage the more widespread adoption in other space applications (e.g., fluid pumps, reaction wheels) that challenge conventional bearing technologies.

References

1.
Knox
,
J. C.
,
2000
, “
International Space Station Carbon Dioxide Removal Assembly Testing
,”
SAE
Paper No. 00ICES-234.10.4271/2000-01-2345
2.
Matty
,
C. M.
,
2010
, “
Overview of Carbon Dioxide Control Issues During International Space Station/Space Shuttle Joint Docked Operations
,”
AIAA
Paper No. 2010-6251.10.2514/6.2010-6251
3.
Howard
,
S. A.
,
DellaCorte
,
C.
, and
Dube
,
M. J.
, “
Magnetic Levitation Long-Life Space Mechanisms: Technology Assessment and Remaining Challenges
,” NASA, Cleveland, OH, Report No. NASA/TM-2019-220052.
4.
Filatov
,
A.
, and
Hawkins
,
L.
, April
2016
, “
Comparative Study of Axial/Radial Magnetic Bearing Arrangements for Turbocompressor Applications
,”
Proc. Inst. Mech. Eng., Part I: J. Syst. Control Eng.
,
230
(
4
), pp.
300
310
.10.1177/0959651815593649
5.
Filatov
,
A.
,
2013
, “
Electromagnetic Actuator
,” U.S. Patent No. 8,482,174.
6.
Filatov
,
A.
, and
Hawkins
,
L.
, “
An Axial Position Sensor for Active Magnetic Bearings
,”
ASME
Paper No. GT2010-22524.10.1115/GT2010-22524
7.
Filatov
,
A.
, and
Hawkins
,
L.
,
2012
, “
Constant-Flux Edge Sensor
,”
Proceeding of 13th International Symposium on Magnetic Bearings
, Arlington, VA, Aug. 6–9, Paper No. 84.https://www.calnetix.com/sites/default/files/Constant-Flux%20Edge%20Sensor%20_%202012.pdf
8.
Filatov
,
A.
, and
Bowman
,
J.
,
2017
, “
Homopolar Permanent-Magnet-Biased Active Magnetic Bearing With an Integrated Rotational Speed Sensor
,” U.S. Patent No. 9,559,565.
9.
Wilkes
,
J.
,
Moore
,
J.
,
Ransom
,
D.
, and
Vannini
,
G.
,
2013
, “
An Improved Catcher Bearing Model and Explanation of the Forward Whirl/Whip Phenomenon Observed in Active Magnetic Bearing Transient Drop Experiments
,”
ASME
Paper No. GT2013-94594
.10.1115/GT2013-94594
10.
Smalley
,
A. J.
,
Darlow
,
M. S.
, and
Mehta
,
R. K.
,
1978
, “
The Dynamic Characteristics of O-Rings
,”
Trans. ASME
,
100
(
1
), pp.
132
138
.10.1115/1.3453877
11.
Keogh
,
P.
,
Aeschlimann
,
B.
,
Hawkins
,
L.
,
Jayawant
,
R.
,
Koehler
,
B.
, and
Maslen
,
E.
,
2018
, “
Activities of ISO/TC 108/SC 2/WG 7 in the Development of Standards for AMB Systems
,”
Proceeding of 16th International Symposium on Magnetic Bearings
, Beijing, China, Aug. 13–17, Paper No. 146.
12.
Hawkins
,
L.
,
Wang
,
Z.
, and
Nambiar
,
K.
,
2018
, “
Floating Shock Platform Testing of a Magnetic Bearing Supported Chiller Compressor: Measurements and Simulation Results
,”
ASME
Paper No. GT2018-77031.10.1115/GT2018-77031
13.
Bathe
,
K. J.
,
1996
,
Finite Element Procedures in Engineering Analysis
,
Prentice Hall
, Englewood Cliffs,
NJ
.
You do not currently have access to this content.