US 5,636,708 A · Method and device for broad temperature range vapor lubrication

Abstract

Conventional liquid lubrication requires a compromise between high temperature properties for good lubrication and low temperature properties for pumpability. The major thrust of this invention is the preservation of the long life and reliable mechanism of elastohydrodynamic lubrication in the pursuit of elevated temperature lubrication. The mechanism of EHD lubrication is the primary source of lubrication for rolling element bearings, gears and other non-conforming contacting surfaces which must carry high loads over small areas of contact. The invention supplies the lubricant as a vapor which upon condensation provides an efficient replenishment of the inlet region to the elastohydrodynamic contact. The surfaces are encouraged to operate at elevated temperatures without cooling for reasons of efficiency. Broad temperature range EHD lubrication with perfluoroalkylpolyether fluids provide full EHD lubrication up to 500.degree. C. The enhanced temperature range, small fluid quantity and the supply of lubricant in a vapor environment eliminates the need for complex lubrication and cooling hardware. The vapor lubrication scheme when applied to a rolling element bearing provides lubrication to 500.degree. C. The invention provides high speed operation to 0.9 MDn (30,000 rpm with a 30 mm bore bearing) with the use of a driving air to overcome the internal windage generated by the high speed components.

Claims28

Dependent claims

An apparatus for the vapor lubrication of a contact surface over a selected temperature range, which apparatus comprises:

a. said non-conforming contacting surface adapted to carry a high load over at least one area of contact;
b. means to supply at least one lubricant material in condensate state, said lubricant material having a vaporization temperature above the range of temperature operation of the contacting surface, and a condensation temperature within the range of temperature operation of the contacting surface, and further characterized in that said lubricant material exhibits the property that its vaporization occurs:
i) without solid decomposition products at temperatures within the range of temperature operation of the contacting surface;
and,
ii) without reaching an auto ignition temperature within the range of temperature operation of the contacting surface;
c. means to vaporize said lubricant material to form a lubricating vapor;
d. means to deliver said lubricating vapor into proximity of said contacting surface such that said vapor impinges upon said contacting surface, permitting condensation of a sufficient quantity of said lubricating vapor on the inlet region of said contacting surface, to provide elastohydrodynamic (EHD) lubrication of said contacting surface by the condensation of said lubricant material.

4 more elements

An apparatus for the vapor lubrication over a broad range of temperature operation of a non-conforming contacting surface carrying high loads over at least one area of contact, which apparatus comprises:

a. said non-conforming contacting surface adapted to carry a high load over at least one area of contact;
b. means to supply a plurality of lubricant materials in condensate state, said lubricant materials comprising a blend of materials each having a vaporization temperature within a selective range within the range of temperature operation of the contacting surface, such that the vaporization temperature of the blend is substantially coextensive with the range of temperature operation of the contacting surface, and further characterized in that each lubricant material is itself a fraction of polymers of similar composition and molecular weights, and exhibits the property that its vaporization occurs:
i) without solid decomposition products at temperatures within the range of temperature operation of the contacting surface;
and,
ii) without reaching an auto ignition temperature within the range of temperature operation of the contacting surface;
c. means to create a lubricating vapor from said plurality of lubricating materials by heating said materials to a temperature above the operating temperature of said contacting surface, thereby vaporizing at least one of said plurality of lubricating materials;
and,
d. means to deliver said lubricating vapor into proximity of said contacting surface such that said vapor impinges upon said contacting surface, permitting condensation of sufficient quantity of said lubricating vapor of at least one lubricant material on the inlet region of said contacting surface, to provide elastohydrodynamic (EHD) lubrication of said contacting surface by the condensation of said lubricant material.

5 more elements

Dependencies are inferred from the claim text.

Method and device for broad temperature range vapor lubrication

Life of this patent

Method and device for broad temperature range vapor lubrication

Life of this patent

Abstract

Claims28