Rotary expansible chamber devices – Specific material
Patent
1990-12-28
1992-06-30
Cuda, Irene
Rotary expansible chamber devices
Specific material
29888025, 298897, 419 38, F03C 200
Patent
active
051258110
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a compressor vane and, more particularly, a sintered iron-base alloy vane for a compressor required to have wear resistant properties.
BACKGROUND ART
In general, as a material for fluid-pressurizing vanes which are sliding parts of compressors, there have generally been used special cast irons, and high-carbon or high speed tool steels with excellent wear resistance. Also, carbon vanes are sometimes used for heavy-load compressors.
However, with development of compressors with higher performance and larger load-carrying capacity, it has been found that the special cast-iron vanes involve such a problem that they are poor in wear resistance. On the other hand, the high-carbon or high speed tool steel vanes possess excellent wear resistance as their hardness may be improved by thermal treatments, but they attack opposing parts and cause seizure because of their poor self-lubricating ability. Also, the carbon vanes have such a problem that they are too expensive.
Recently, sintered alloy vanes produced by sintering have partially received practical application. Such sintered alloy vane are composed, as disclosed in the Japanese Patent Gazette of laying-open No. 59-16952 for example, of a sintered iron-base alloy consisting of a matrix of a base metal of iron and hard particles such as carbides dispersed in the matrix. In such vanes, the mechanical strength of the matrix is ensured by increasing the theoretical relative density to not less than 92%, while the wear resistance is improved by dispersion of the hard particles with a diameter of not less than 5 .mu.m into the matrix. Also, such sintered alloy vanes have a further advantage such that they possess self-lubricating when oil is impregnated into their pores.
However, the above sintered iron-base alloy vanes attack opposing parts and cause a seizure in a manner similar to the aforesaid steel vanes because of their high hardness of a macro-structure including the dispersed hard particles, which results from high theoretical relative density of not less than 92%.
DISCLOSURE OF INVENTION
The present invention has been made under such situations of the prior art to provide a sintered iron-base alloy vane, which possesses high wear resistance but does not damage opposing parts, for use in compressors which are advancing increase in performance and in load-carrying capacity.
According to the present invention, the above and other objects are achieved by molding a sintered iron-base alloy, which is composed of a matrix of a base metal of iron and containing hard carbides uniformly dispersed therein, and which consists essentially of 0.7 to 1.5% by weight C, 3.0 to 5.0% by weight Cr, 0 to 10.0% by weight Mo, 1 to 20.0% by weight W, 0.5 to 6.0% by weight V, 0 to 15.0% by weight Co and the balance iron and inevitable impurities, under a pressure of 5 to 8 ton/cm.sup.2, and then sintering compacts at a temperature of less than 1250.degree. C. so as to control particle size of the hard carbide to not more than 5 .mu.m, as well as to control the theoretical relative density to 80 to 90%, and to control the macro-hardness to 10 to 45 in the Rockwell C scale.
The sintered iron-base alloy used for compressor vanes of the present invention is not limited in its composition, and may be the one conventionally used as a sintered material for sintered iron-base vanes, or the one having any composition composed of a base metal of iron and containing a hard carbide uniformly dispersed therein. It is, however, preferred to use a sintered iron-base alloy having a composition consisting essentially of 0.7 to 1.5 wt % C, 3.0 to 5.0 wt % Cr, 0 to 10.0 wt % Mo, 1 to 20.0 wt % W, 0.5 to 6.0 wt % V, 0 to 15.0 wt % Co, and the balance iron and inevitable impurities.
The hard carbide may be the one conventionally used in sintered iron-base alloy vanes. For example, there may be used those such as carbides of Cr, Mo, V, W and the like. It is, however, preferred to use carbides with a particle size of not more than 5 .mu.m.
The above
REFERENCES:
patent: 4490175 (1984-12-01), Matsuzaki
patent: 4772450 (1988-09-01), Friedman
patent: 4817858 (1989-04-01), Verpoort
patent: 4859164 (1989-08-01), Shimomura
Amano Nobuya
Motooka Naoki
Cuda Irene
Sumitomo Electric Industries Ltd.
LandOfFree
Sintered iron-base alloy vane for compressors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sintered iron-base alloy vane for compressors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sintered iron-base alloy vane for compressors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1860003