Note: Radial-thrust combo metal mesh foil bearing for microturbomachinery

Abstract

This Note proposes a novel radial-thrust combo metal mesh foil bearing (MMFB). Although MMFBs have advantages such as higher stiffness and damping over conventional air foil bearings, studies related to MMFBs have been limited to radial MMFBs. The novel combo MMFB is composed of a radial top foil, thrust top foils, and a ring-shaped metal mesh damper--fabricated by compressing a copper wire mesh--with metal mesh thrust pads for the thrust bearing at both side faces. In this study, the combo MMFB was fabricated in half-split type to support the rotor for a micro gas turbine generator. The manufacture and assembly process for the half-split-type combo MMFB is presented. In addition, to verify the proposed combo MMFB, motoring test results up to 250,000 rpm and axial displacements as a function of rotational speed are presented.

Characteristic Analysis of High-Speed Permanent Magnet Synchronous Motor

“…Derived the interference force, it used the equation of the mechanical stress as follow [2], [11] (3)…”

“…The table 3. is shownas the material parameter of the rotor for analytical method, since, the yield strength of PM and sleeve is 35 and 1100 MPa, the maximum stress point should be designed to be lower than the yield strength to prevent fracture [2], [11]. The analytical method results of the mechanical stress according to the interference length are shown as Fig.…”

“…However, the structure is simple and suitable for high-speed machines. Prior to design the machines, mechanical analysis should be considered, the rotor of high-speed machine is made of shrink fit of sleeve and PM that generate mechanical stress and broke the structure of rotor according to interference [2]- [11]. Thus, the design of sleeve thickness is affected by shrink fit and the materials.…”

Experimental study of small-size air turbo blower supported by externally pressurized conical gas bearings

“…Furthermore, small-sized sintered porous bearings with controlled air breathability would be difficult and costly to fabricate. Park [5] researched radial-thrust combo metal mesh foil bearing. While this approach is beneficial in actual use same as mentioned above, thrust bearing has large outer diameter (19.4 mm) compared with radial diameter (11.6 mm).…”

Fabrication of a micro-hole array on metal foil by nanosecond pulsed laser beam machining using a cover plate

“…Nowadays, the demand for thin metal foil has increased with the fast growth of new applications for miniaturized products and components. It is used in various fields such as flexible displays, micro filters, micro actuators, medical devices and metal mesh foil bearing [1][2][3][4]. However, it still remains a crucial issue to achieve the micro-machining of a thin metal foil with high precision.…”