US3514237A - Fluid motion device - Google Patents

Description

May 26, 1970 Yum. @mus lNvENToR E MANI/E L 6. SPYR/DAK/S AGENT United States Patent O 3,514,237 FLUID MOTION DEVICE Emanuel G. Spyridakis, Belle Mead, NJ., assignor to Ingersoll-Rand Company, New York, N.Y., a corporation of New Jersey Filed July 25, 1968, Ser. No. 747,759 lnt. Cl. F01c 1/00; F04c 3/00, 17/00 U.S. Cl. 418-152 4 Claims ABSTRACT F THE DISCLOSURE A fluid motion device, such as a motor, pump, cornpressor, and the like, of the sliding vane type, having at least one additional lubrication vane for reducing the effects of friction between the vanes, cylinder walls, and vane slots. The lubricating vane has relieved areas, on its longitudinal extremities; this avoids pressurization of its one surface and, consequently, minimizes the force and incidence of frictional contact between the lubricating l'vane and its slot.

This invention pertains to fluid motion devices, such as motors, pumps, compressors and the like, which, by way of example, may be of the sliding vane type, and in particular to means for reducing the wearing effects of fric tion between engaging and relatively sliding components thereof, and means for minimizing the force and incidence of frictional contact between components thereof.

To inhibit wear between frictionally engaging and relatively slidable components of fluid motion devices, judicious selection of material has been practiced heretofore. Accordingly, in iluid motion devices of the vane type, for instance, various varie materials have been experimented with so as to extend vane life as a consequence thereof. Accordingly, it is known to use varies which are formed of fiber, nylon, or mechanical carbon.

Mechanical carbon is that material well known in the art which is made by mechanically mixing powdered graphite and carbon with a suitable binder in appropriate proportions, subjecting the mixture to relatively high pressures, baking the mixture and cutting or machining the resulting product into usable shapes and forms.

Such types of vanes, i.e., those of the fiber, nylon, or mechanical carbon type, have not been wholly ineffective toward inhibiting vane wear, however, they are still met with limitations. For instance, all yanes including those types just noted, are subjected to fluid forces tending to urge the trailing sides of the varies into tighter frictional, sliding engagement with the mating walls of the rotor slots. With respect to the use of mechanical carbon, it has been found that, for instance, in vacuum pumps, of the dry vacuum type, using such vanes, the life of the pumps can be reduced through wear of the mechanical carbon vane parts by a factor of 1000 or more when the pump is operated in some given atmospheres. Specifically, these would be atmospheres having widely varying partial pressures of water vapor and/ or oxygen.

Varies of ber or nylon, of course, have a suppleness not to be found in metallic vanes. And yet, the very suppleness thereof can be detrimental to the functioning of the fluid motion device in which they are used. With accelerating pressurization of the chamber and rotor revolution of the device, the fiber or nylon vanes will yield. They exhibit a bending, under the inlluence of the pressure and inertial effects which, for one, tend to detract from the sealing eciency with'which the vane tip can engage the walls of the cylinder of the device. =For another, as the vanes assume a shallow but increasingly bowed, arcuate shape they effect a relative withdrawal from the vane slot. Subsequently, with wear and excessive bowing,

Patented May 26, 1970 the vanes can become canted and wedge-locked in their slots and subsequently disable the fluid motion device.

Accordingly, it is an object of this invention to provide a iiuid motion device of the type which encompasses motors, pumps, compressors, and the like, having means for lubricating the frictionally engaging components thereof, and means for reducing the force and incidence of frictional contact between components thereof.

A feature of this invention comprises the use, in a fluid motion device which, by way of example, is of the sliding vane type, of at least one additional lubricating vane for lubricating between the varies and cylinder walls at least. Another feature of this invention teaches the use of lubricating vanes having relieved areas formed in the longitudinal extremities thereof to avoid pressurization of one surface thereof and accordingly to reduce the force of frictional contact, and wear resulting therefrom, between the lubricating vanes themselves and their slots. Another feature of this invention teaches the use of a lubricating vane having movement-limiting means for reducing the incidence of frictional contact between said vane and other surfaces of the fluid motion device. Further objects and features of this invention will become more apparent by reference to the following description taken in conjunction with the accompanying figures in which:

FIG. l is a vertical crosssection of a fluid motion device according to the invention;

FIG. 2 is an isometric view of a lubricating vane used in the lluid motion device of FIG. l; and

FIG. 3 is a partial, vertical cross-section of an alternate embodiment of a iluid motion device in which radial bores in the rotor pressure-relieve the lubricating vane.

A -uid motion device 1, according to the invention, as shown in FIG. 1, comprises a housing 2 which presents an inner chamber 3 having in communication therewith an inlet duct 4 and an outlet duct S for iluid. The physical structural features of inlet and outlet ducts 4, 5, and the manner of their iixture to, and incorporation with, housing 2 and chamber 3 is not shown. But such structures are notorious in the art; specific structures therefor are not pertinent to the instant invention: accordingly, thev are no more symbolically represented.

A rotor 6 is rotatably supported Within chamber 3 and has slots 7 formed therein, which extend parallel with the rotor axis, to receive fluid motion varies 8 which are of rigid, for instance, metallic or phenolic material. Varies 8 are slidably mounted within slots 7 and, under the inuence of centrifugal force, as rotor 6 rotates eccentrically within chamber 3, slide outwardly to contact the inner Walls 9 of chamber 3. An additional lubricating vane 10 is arranged between said walls 9 and rotor 6, the same being interposed between a pair of adjacent fluid motion vanes 8 at least for direct lubrication of the walls 9 of chamber 3 and consequentially, and indirectly, depending upon the type of lubrication vane 10 employed, for lubrication between varies 8 and slots 7.

Only one lubricating vane 10 is shown, but this is solely for purposes of teaching an example. In practice, it is advisable to employ a second lubricating vane, slidably disposed in rotor 6 on the side opposite vane 10, to insure a dynamic balancing of the rotor 6. Further, to assure long-lived lubrication of the fluid motion device 1, it is desirable to employ four lubricating vanes, arranged equally-spaced about the rotor, between vanes 8. These are matters of choice; the teaching of my inven tion embraces all such embodiments and others as will occur to those skilled in the art.

Lubricating vane 10, as can best be seen in FIG. 2, has relieved areas 11 formed at the longitudinal ends thereof. Said relieved areas are provided for admitting fluid therethrough so as to limit a build-up of fluid pressure on the pressure surface of the vane 10.

Slots 7, of course, are of a cross-sectional dimension slightly greater than that of the gauge of vanes 8 and 10. It is because of the clearance provided thereby that the vanes can slide in response to centrifugal force. However, under the influence of inertia, and the build-up of fluid pressure -against whichever surface of vanes 8, 10 is the pressure surface, the vanes angle in the slots 7. That is to say that they assume as much of a canted angle, in slots 7, as the provisioned clearance will allow. Then, as the vanes slide inwardly and outwardly, in slots 7, considerable-friction and wear occurs between the sides vof the vanes and those of the slots.

Lubricating vane 10, in having relieved areas 11 at the ends thereof is lessened in mass, and, accordingly, is less subject to inertial effects. Further, as the relieved areas 11 admit uid therethrough, there is less pressure buildup on the pressure surface thereof. These factors, then, contribute to lessen the degree of angulation which vane 10 mainfests in its slot 7, inhibit the force with which vane 10 will bear against the slot 7, and resultingly reduce the amount of friction occurring between the vane and the slot.

Vane 10 is a lubricating element, composed of materialby way of example-such as mechanical carbon, or polytetrafluoroethylene, or like substances. Through its wiping action against walls 9, it deposits a illm of lubricant-graphite, or polytetrailuoroethylene-there upon to reduce the effects of frictional contact between the tips of vane 8, 10 and walls 9. Further, if the Vane 10 is mechanical carbon, some of its deposition migrates from the walls 9 and the tips of the vanes 8, to the surfaces of vanes 8 to film the surfaces of the frictionally engaging and relatively sliding vanes 8 and slots 7 therebetween.

Broadly, my invention teaches the use of a lubricating vane 10 and, in its preefrred embodiments, contemplates a lubricating vane of mechanical carbon, polyamide, or polyteralluoroethylene. However, the practice of my invention will embrace use of a lubricating vane having a lubricating oil wick extending therefrom, for reducing friction, and all such means associated with a lubricating vane, and drawn to inhibiting friction, as will suggest themselves, to those skilled in this art, through my teaching.

It is to be noted that, as shown in FIG. 2, vane 10 has a plurality of slots 12 formed therethrough which extend radially (from the axis of rotor 6) along an intermediate portion of vane 10. Said slots 12 are in line with bores 13, formed perpendicularly relative thereto, in rotor 6 to receive limit pins 14. The purpose of slots 12 and limit pins 14 is to inhibit the outward thrust of lubricating vane 10 in response to centrifugal force.

'When fluid-motion device 1 is initially constructed, a full-width lubricating vane 10 is arranged therein. With rotation of rotor 6, vane 10 responds to centrifugal force and wipingly makes full contact with the walls of chamber 3. After a period of time, however, as some of the material of vane 10` is given up as lubricant deposition, the width of said lubricating vane is reduced. To avoid excessive wear of lubricating vane 10, i.e., wear thereof lto the point where it is so narrow as to become greviously canted in its slot 7, slots 12 and pins 14 limit its outward thrust. The dashed-line portion of vane 10, shown in FIG. 2, shows the amount of wear, via deposition, that has been experienced by the vane 10 in FIG. 1. As it can be appreciated from FIG. 1, vane 10 -finds the inner terminations of slots 12 bearing against pins 14. Thus, the partially worn vane 10 sweeping from A to B (FIG. 1), about the expanding sector of chamber 3, does not contact walls 9. As it sweeps from A to B, about the contracting sector of chamber 3, it does contact walls 9. Some of the deposition made on walls 9 in the latter sector is carried by vanes 8, via the tips thereof, to walls 9 of the former sector. Accordingly, during a portion of the rotation of rotor 6, a partially worn lubricating vane 10 makes frictional contact with the inner walls 9 of chamber 3, and also: for the remaining portion of rotation of' rotor 6 said partially worn vane 10 is restrained from making a contact with the inner walls of chamber 3. In this manner, excessive wear of lubricating vane 10 isavoided while fluid motion vanes 8 nonetheless carry the lubricant deposition fully about the whole circumference of the inner walls 9 ofvchamber 3.

An alternate embodiment of my invention, as shown in FIG. 3, dispenses with the provisioning of relieved areas 11 in lubricating vane 10. In this embodiment, full dimensioned lubricating vanes are used. The pressure relieving means therefor are provided by a plurality of radial bores 15, formed in rotor 6, which communicate with, and provided a pressure by-pass through the slot 7 which carries the lubricating vane. It is arranged that bores 15 do not intersect bores 13. The former are formed in given planes along the axis Of rotor 6, and the latter are drilled in axial planes occuring between pairs of adjacentbores 15.

The teaching of my alternate embodiment can be practiced in vane-type fluid motion devices and in piston-type devices as well. In the latter application, a lubrication piston ring would be pressure-relieved by bores formed in the piston body to by-pass said lubrication piston ring.

In both embodiments, my invention teaches a fluid motion device which accommodates the use of dissimilar vane or piston ring materials, to wit: phenolic and mechanical carbon, or phenolic and polytetrafluorethylene, or steel and phenolic, or metal and mechanical carbon, and the like, the lubricating vane or ring being the latter of these few examples of paired materials.

`It is a teaching of my invention, then, to provided a iluid motion device of the type which encompasses motors, pumps, compressors, and the like, having first means which. frictionally contact the inner walls of a chamber of the device, at least to communicate Huid therethrough, and second means for lubricating both said walls and said first means and in Iwhich device has mean for reducing the force and incidence of frictional contact with between said lubricating means and said first means. Further, my invention teaches the use of su-ch aforenoted lubricating means together with means which further provide for reducing the incidence of said lubricating means contact with said walls.

While I have described my invention in connection with specific embodiments thereof, itis to be clearly understood that this is done only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.

I claim:

`1. A fluid-motion device of the type which encompasses motors, pumps, compressors, and the like, comprising:

a housing having a chamber therewithin;

said chamber having fluid inlet and outlet means; and

means in plurality, movable within said chamber,

which, during movements thereof, make frictional contact both therebetween and with inner walls of said chamber; and

wherein one of said means comprises an axially slotted rotor with a plurality of radially slidable vanes and effects communication of fluid between said inlet and said outlet means; another of said means comprises at least one Vane carried within and radially slidablewithin a slot in said rotor and lubricates said walls and said fluid communication means; and further comprising means for reducing the force with which said lubricating means makes frictional contact with said fluid [communication means,

said one vane and said rotor having means for limiting the response of said one vane to centrifugal force,

said limiting means comprises slotting formed through said one vane, along a radial plane for receiving limiting pins therethrough.

2. A uid-motion device of the type which encompasses motors, pumps, compressors, and the like, comprising:

a housing having a chamber therewithin;

said `chamber having uid inlet and outlet means; and

means in plurality, movable within said chamber, which, during movements thereof, make frictional contact both therebetween and with inner walls of said chamber; and

`wherein one of said means at least elects communication of uid between said inlet and said outlet means;

another of said means comprises a radially slidable vane mounted within a radially slotted rotor and lubricates said walls and said fluid communication means; and further comprising means for reducing the incidence of contact which said lubricating means makes with said walls,

said means for reducing the incidence of contact between said lubricating vane and said inner walls comprises slotting formed through said lubricating vane, along a radial plane, for receiving radial movement limiting pins therethrough.

6 3. The device, according to claim 1, wherein: said vane is a mechanical carbon component formed of graphite, carbon, and binder material. 4, The device, according to claim 1, wherein: said vane is formed of polytetrauoroethylene.

References Cited UNITED STATES PATENTS 1,992,848 2/1935 Wade.

2,616,615 11/1952 Scott.

2,636,667 4/1953 Frei 230--152 X 2,833,465 5/1958 Cable.

2,905,376 9/1959 Davey 230-152' 3,014,431 12/1961 Van Den Bussche.

3,374,943 3/1968 Cervenka 230-152 3,398,884 8/1968 Kaatz et al 230--152 3,419,208 l2/1968 Brewer et al 230--152 X 3,451,346 671969 Pettibone 10.3-136 2O DONLEY J. STOCKING, Primary Examiner W. I. KRAUSS, Assistant Examiner U.S. Cl. XR.

25 9 1-137; 12s-s; 23o-152, 418-112

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