Abstract:
A foil thrust bearing assembly (12) for an oil-free turbocharger including a top foil member (26a, 526b, 126, 226) and a circular bump foil member (28a, 28b, 128, 228). The top and bottom foil members (26a, 26b, 126, 226) and (28a, 28b, 128, 228) include step surfaces (50, 150, 250) and (64, 264), respectively, that aid in positioning the foil thrust bearing assembly (12) within the bearing housing (32a, 32b).
Abstract:
A bearing housing (12) for a turbocharger having a rotatable shaft (14) passing through the bearing housing (12) with journal bearings (30) having flexure pivot tilting pads (40) for supporting the rotatable shaft (14) in the bearing housing (12). The flexure pivot tilting pads (40) may have oil supply holes (50) through each pad (40) to direct lubrication to each pad surface (44). The journal bearings (30) preferably have a circumferential groove (52) on an outer surface of the bearing aligned with the oil supply holes (50) to help feed oil to the oil supply holes (50).
Abstract:
A turbocharger is provided with an improved bearing which is formed as a floating ring bearing or a semi-floating ring bearing having a conical or hemispherical shape which supports both journal and thrust loads. The floating ring bearing may have conical floating ring bearings (70), (100), (180) that define inner and outer conical bearing surfaces (71), (108), (185) and (72), (109), (186) which cooperate on the inside with corresponding conical journals (75/76), (1 1 1/1 12), (187/188) that rotate with the shaft (53), and cooperate on the outside with a stationary bearing housing (52) to form inner and outer fluid films. Alternatively, the floating ring bearing may have a pair of hemispherical floating ring bearings (85), (140), (210) that have hemispherical inner and outer bearing surfaces (86), (144), (21 1) and (87), (145), (212) which form inner and outer fluid films. A semi-floating ring bearing may also be provided with these structures.
Abstract:
A turbocharger 51 is provided with an improved bearing 52, preferably formed as a semi-floating ring journal bearing which has hydrodynamic flexure pivot tilting pads 53 on the inner diameter thereof and compliant structural dampers 54 on the outer diameter thereof. The compliant structural dampers 54 are installed between an outer bearing surface and an inner surface of a bearing chamber 56. These compliant structural dampers 54 can be formed as metal mesh dampers 71 or bump foil dampers 72 which are effective to dissipate mechanical energy from structural damping and dry-friction.