Bearings – Rotary bearing – Fluid bearing
Patent
1997-05-27
1999-01-26
Footland, Lenard A.
Bearings
Rotary bearing
Fluid bearing
F16C 1702
Patent
active
058631330
DESCRIPTION:
BRIEF SUMMARY
This invention relates to vertical bearing assemblies employed to support vertically extending rotatable shafts and provide thrust and/or journal bearing support therefor, and in particular relates to lubricant arrangements therefor.
A vertical bearing assembly of known form, employed to support a vertical shaft which is capable of being rotated about its longitudinal axis in either rotational direction, is illustrated in sectional elevation in FIG. 1.
A shaft 5 having longitudinal axis 6 is suspended from its upper end 7 by a vertical bearing assembly shown generally at 10. The bearing assembly comprises a collar 11 surrounding the end 7 of the shaft and rotatable with the shaft as a rotor part, which collar has an axially extending part 12 and a radially enlarged flange 13 to define radially extending, axially directed faces 14 and 15. The bearing assembly also comprises a stator housing 20 which surrounds the collar 11 and contains other stator parts of the assembly.
The bearing assembly comprises several bearing parts contained within the housing and is shown comprising a main thrust bearing part 21, in the form of a ring of bearing pads 22 carried by the stator arrayed about the shaft to support the shaft by way of the face 14 of the collar flange, a reverse thrust bearing part 23, in the form of a ring of small bearing pads 24 supported by the structure to engage with the flange face 15, and a journal bearing part 25, in the form of a plurality of bearing pads 26 carried by the stator and arrayed about the axially extending part 12 of the collar.
The bearing parts are of conventional bearing material, such as white metal on a backing metal, and operate with an intervening film of liquid lubricant, formed by filling the housing with lubricant 27 to a level 27' above the highest bearing part, that is, with the bearing parts totally immersed in a bath of the lubricant. The bearing pads are also mounted such that they have a limited degree of tilt to permit the lubricant film to adopt a wedge-like thickness due to hydrodynamic forces during rotation and to accommodate minor misalignment between the shaft and stator.
The total immersion of the bearing surfaces within the lubricant ensures that a hydrodynamic film is available at all times without priming; the bearing assembly is thus fully contained within the housing and for this reason is sometimes referred to as being of the vertical self-contained type.
Notwithstanding that the housing parts are totally immersed in a bath of lubricant, reliance on the lubricant and its inherently low pressure head and poor extraction of heat means that the power envelope of such bearing assembly is limited and determined to a significant extent by the thermal properties of the lubricant. In particular, although lubricant is moved through the bearing parts to some extent by the shaft rotation and viscous drag on the lubricant film, the rate of flow and/or hydrodynamic pressure is limited by shaft rotation speed and lubricant temperature in the vicinity of the bearing parts. Heat generated at the bearing parts limits the speed at which the shaft can be rotated and/or the load carried by the shaft unless the heat is removed from the bearing parts by way of the lubricant of the bath and/or stator and housing structure.
The structure of the stator inhibits convection currents within the lubricant from adequately distributing it through the bath.
It is known to provide heat exchange pipes within the bath of lubricant and through which a coolant is caused to flow to extract heat from the bath of the lubricant, and indicated by ghosted lines 28.
It is known alternatively to provide the housing with external fins 29.sub.1 or the like and to dispose the whole housing in a ducted stream of cooling fluid, such as air forced to flow over the fins by a fan 29.sub.2 carried at the end of the shaft or collar, or to surround the housing with a water jacket.
However, such known arrangements of influencing the power envelope of the bearing assembly by influencing the behaviour and funct
REFERENCES:
patent: 1460353 (1923-06-01), Williamson
Footland Lenard A.
The Glacier Metal Company Limited
LandOfFree
Vertical bearing assembly lubrication does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vertical bearing assembly lubrication, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vertical bearing assembly lubrication will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1445419