Precision Linear Flexure Bearing Cartridge

Segmented diaphragm linear flexure bearings are the single major innovation which has extended the service life of linear drive cryocoolers from a 4,000 hour mean time to failure to a potential 80,000 hour operational life. Unfortunately, the design, fabrication, installation, and alignment of such bearings is an art. Material selection, fabrication processes, quality control, allowable cyclic stress, dynamic behavior, mounting provisions, alignment processes, radial/axial stiffness, and the establishment and maintenance of radial clearances are reoccurring problems with each new application. The spiral cut diaphragm is the prevalent configuration. The three leg tangential configuration is a recently described alternative with lower peak stress per unit radial stiffness. This improvement does not resolve the design, fabrication, installation, and alignment problems. This project will examine and compare the spiral and tangential flelxure for designing reproducible, highly reliable, long life, radially stiff elements for assembly in integral precision cartridges. The innovative aspect is to develop a metallurgically bonded precision aligned integral bearing cartridge with tight tolerance internal and external mounting diameters. Such cartridges, externally similar to ball bearing cartridges, will greatly simplify the use of these bearings. The metallurgical bonding process will be demonstrated and evaluated.