Long-term lubrication of momentum wheels used in spacecrafts—An overview

Sathyan, K.; Hsu, Hung-Yao; Lee, Sang‐Heon; Gopinath, K.

doi:10.1016/j.triboint.2009.05.033

Cited by 62 publications

(32 citation statements)

References 17 publications

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“…In rotating shaft design, the bearing housing is rigidly mounted on www.intechopen.com the base plate of the wheel and the flywheel and the motor rotor are mounted on the shaft (Honeywell, 2003). In the rotating housing type, the bearing unit shaft is mounted on the base plate and the flywheel and motor rotor are mounted on the bearing housing (Auer, 1990;Jones and Jansen, 2005;Sathyan, 2003). Fig.…”

Section: Bearing Unitmentioning

confidence: 99%

“…If the value of < 3, it will lead to mixed lubrication with some asperity contacts (Hamrock and Dowson, 1981). The calculated film thickness and ratio for a typical momentum wheel bearing (20 mm bore, 6.35 mm ball, ABEC 9P class) operating at 5400 rpm with a lubricant having pressure-viscosity coefficient 2 x 10 -8 m 2 /N and a bearing preload 50 N is 0.62 mm and 13.4 for the inner race contact and 0.76 mm and 16.3 for the outer race contact, respectively (Sathyan, 2003). Experimental verification of film thickness has been done by Coy et.al.…”

Section: Tribology Of Attitude Control Systemsmentioning

confidence: 99%

“…The ISOFLEX PDP65. A diester oil produced by Kluber Lubrication is a proven momentum wheel lubricant (Sathyan, 2003). This lubricant has very high viscosity index [235] and very low pour point [-60°C].…”

Section: Estersmentioning

confidence: 99%

“…It is actuated when the bearing temperature increases due to higher friction, demanding lubricant. Another type of in-situ lubrication system is the static lubricant reservoir (Sathyan, 2003), consists of a porous material reservoir of cylindrical shape mounted on an aluminum sleeve. An electric foil heater is pasted inside the aluminium sleeve.…”

Section: Active Lubrication Systemsmentioning

confidence: 99%

See 3 more Smart Citations

Lubrication of Attitude Control Systems

Sathyan¹,

Lee²,

Hsu³

et al. 2011

Advances in Spacecraft Technologies

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Section: Bearing Unitmentioning

confidence: 99%

Section: Tribology Of Attitude Control Systemsmentioning

confidence: 99%

Section: Estersmentioning

confidence: 99%

Section: Active Lubrication Systemsmentioning

confidence: 99%

See 2 more Smart Citations

Lubrication of Attitude Control Systems

Sathyan¹,

Lee²,

Hsu³

et al. 2011

Advances in Spacecraft Technologies

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“…It is characterized by large variation in bearing friction torque associated with [25] severe audible noise. Uneven cage wear, lubricant degradation, and insufficient lubrication are the prime causes for it.…”

Section: Bearing Unitmentioning

confidence: 99%

Development of a Lubrication System for Momentum Wheels Used in Spacecrafts

et al. 2008

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The success of any satellite mission largely depends upon the performance of the attitude control systems such as gyroscopes and momentum/reaction wheels. The required life and performance quality of these rotating mechanisms are ensured by the selection of bearings and its lubrication. The design and development of lubrication system to meet the long-term uninterrupted performance is a challenging task before the tribologists. This article describes the developmental study of a lubrication system for long-term requirements of momentum/reaction wheels. The developed system is compact and can be placed inside the bearing unit assembly. It works on centrifugal force and able to supply lubricant continuously at a very low rate of few micrograms per hour for many years. Further, the system can be tuned for any flow rate depending on the requirement.

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Design and Pore Properties Tuning of Two‐Scale Porous Polyimide Fabricated by Isostatic Pressing for Improving Oil Storage and Tribological Properties

Guo

Ruan

et al. 2022

Adv Eng Mater

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The development of smart lubricating materials with lasting lubrication and outstanding wear resistance while achieving speed response is of great significance in the field of bearing cage applications but has proven to be challenging. Herein, polyimide (PI) molding powder containing two kinds of PI with different rigidities is synthesized in situ to fabricate a two‐scale porous polyimide (PPI) by (cold and hot) isostatic pressing. The unique two‐scale porous structure originates from the bimodal particle size distribution of the PI molding powder. The oil stored in the two‐scale PPI is gradually thrown out as the rotation speed increases, which makes the two‐scale PPI suitable for bearing cages with a wider rotation speed range and realize persistent and stable oil supply under different speeds. The porosity of PPI decreases with increasing pressure during hot isostatic pressing, but the effect of temperature on the porosity is not obvious. Moreover, the two‐scale PPI maintains good mechanical properties, and its ring tension is as high as 22.3 MPa. Due to the high oil content (>15%) and excellent oil retention rate (93.3%, at 3000 rpm for 180 min), the two‐scale oil‐containing PPI exhibits a stable low friction coefficient (≈0.096) and ultralow wear rate (≈0.68×10−6mm3 (Nm)−1).

show abstract

Long-term lubrication of momentum wheels used in spacecrafts—An overview

Cited by 62 publications

References 17 publications

Lubrication of Attitude Control Systems

Lubrication of Attitude Control Systems

Development of a Lubrication System for Momentum Wheels Used in Spacecrafts

Design and Pore Properties Tuning of Two‐Scale Porous Polyimide Fabricated by Isostatic Pressing for Improving Oil Storage and Tribological Properties

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