Bearings – Rotary bearing – Hydraulic or pneumatic bearing support
Patent
1984-12-11
1987-02-10
Levy, Stuart S.
Bearings
Rotary bearing
Hydraulic or pneumatic bearing support
384101, 384126, 384287, 384512, 384513, 384901, F16C 2100, F16C 3358
Patent
active
046419772
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to bearing systems for shafts that rotate at high speeds, and more particularly to bearing systems applicable to machines with shafts that rotate at high speed and are exposed at one end to high temperatures, such as turbochargers for internal combustion engines.
BACKGROUND ART
It is desirable to provide, in high-speed machinery, anti-friction rolling bearings, such as ball bearings or roller bearings, to reduce friction and permit high-rotational speeds with low-energy loss. However, in machines having shaft-rotating speeds on the order of 60,000 or 80,000 rpm, such bearings have a limited life on the order of 500 hours. Such a limited life is not acceptable in many commercial applications and, particularly, in applications such as the turbochargers for internal combustion engines.
Turbochargers for internal combustion engines are now widely used in conventional automobiles, and bearing systems, particularly as adapted for use in turbochargers, must be capable of mass-production methods and must be economical to manufacture and service. In addition, such bearing systems must have a long life and must not be subject to breakdown at relatively short intervals such as 500 hours. Since anti-friction bearings such as roller bearings and ball bearings are expensive and have too short an operating life for commercial use in automotive turbochargers, it has been conventional practice to provide sleeve bearings in such applications.
Conventional sleeve bearings have been found objectionable in these applications because they would not tolerate a practical degree of imbalance in their supported rotating parts and because they were incapable of damping resonant vibrations of the rotating parts due to such imbalance. Instead of rotating about a stationary center, unbalanced high-speed, rotating shafts have a tendency to whirl about in such a manner that their centers travel through a circular or modified circular path. Conventional bearing clearances limit such a whirling motion; but at speeds on the order of 80,000 rpm or more, metal-to-metal contact and rapid wear of the bearings occur as a result of oil film breakdown due to lubricating oil film dynamics and bearing loads.
A number of prior bearings have resulted from these problems. Among the patents disclosing bearings resulting from such problems, are prior U.S. Pat. Nos. 3,056,634; 3,096,126; 3,390,926; and 3,993,370. These patents are directed to bearings to provide stability at high speed with the ability to absorb vibration and shock load of the type experienced by bearing systems, for example, in turbochargers, and to be manufactured at low cost. The bearings of the patents above generally solved the stability problem by the use of a free-floating bushing between the rotating shaft and its stationary supporting member which was adapted to provide a film of lubrication between its inner surface and the rotating shaft and between its outer surface and the stationary supporting member. In these systems, the free-floating bushing was free to rotate, but at speeds substantially less than the rotating shaft and was free to move radially in response to imbalance experienced by the rotating shaft. The freedom of radial movement permitted the rotating shaft to rotate about its center of mass and the inner and outer oil films provided the necessary lubrication and cushion against vibration and shock loads. The problem of "oil whirl" where the pressures in the film of lubrication go to zero and the shaft contacts the bearing surface was solved.
The bearings of these patents also provided thrust-bearing surfaces as, for example, in U.S. Pat. No. 3,390,926 and employed the increased frictional drag at the outer bushing surface to reduce the rotational speed of the bushing to a fraction of the rotating shaft speed and passageways in the bearings themselves to direct oil from the outer surface to the inner surfaces and thrust-bearing surfaces.
U.S. Pat. No. 4,370,106 suggests a bearing system for a turbocharger rotor, including
REFERENCES:
patent: 3043636 (1962-07-01), MacInnes et al.
patent: 3056634 (1962-10-01), Woollenweber, Jr. et al.
patent: 3058787 (1962-10-01), Bernson
patent: 3068638 (1962-12-01), Birmann
patent: 3096126 (1963-07-01), Woollenweber, Jr. et al.
patent: 3218029 (1965-11-01), Woollenweber, Jr.
patent: 3270495 (1966-09-01), Connor
patent: 3292092 (1966-12-01), Germann
patent: 3292364 (1966-12-01), Cazier
patent: 3383092 (1968-05-01), Cazier
patent: 3390926 (1968-07-01), Woollenweber, Jr.
patent: 3408046 (1968-10-01), Woollenweber, Jr.
patent: 3423926 (1969-01-01), Nancarrow et al.
patent: 3614259 (1971-10-01), Neff
patent: 3811741 (1974-05-01), McIrney et al.
patent: 3930747 (1976-01-01), Woollenweber
patent: 3993370 (1976-11-01), Woollenweber
patent: 4169354 (1979-10-01), Woollenweber
patent: 4370106 (1983-01-01), Lauterbach
Levy Stuart S.
Werner David
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