USRE19783E - Compressor - Google Patents

Description

rroamsys. 7

iiwmon. 050126: E. Rowers 97w 2 ShQets Sheet 1 MN I COHPRES SOR s. E. ROBERTS Dec. 3,- 1935. e. E. ROBERTS Re. 19,

' r cournssson Original Fi ed u l 26, 1932' 2 Shuts-Sheet 2 I INVENTOR.

ATTORNE "Man/ 05217 650262 E. Boner;

Reissued bca-3f Q 7 UNITED STATES I PATENT on-ice George'E. Roberts, Burbank, Calif., assign of one-fourth to Rudolph A. Rich and one-fourth to Forest 0. Rick, both of Rhinelander, Wis.

Original No. 1,931,207, dated October 17, 1933, Serial No. 613,735, May 26, 1932. Application for reissue August 13, 1934, Serial No. 739,707

3 Claims- (Cl. 103-139) This invention relates to rotary compressors, rotor. To produce a highly effective fluid seal and while it is designed more especially for use in between the stator, the rotor and the vanes, it is systems of mechanical refrigeration. it canalso intended that the vanes freely move axially of be advantageously employed in hydraulic transthe rotor and relatively to the cam side of the missions and wherever it may be desired to cirstator so that their adJacent fluid sealing edges 5 culate or compress fluid in a simple and emcient can be effectively advanced against the coasting manner. face of the stator wall.

One of the objects of the invention is to pro- Wlth the foregoing and other objects in view, vide a rotary compressor made up of the miniwhich will appear as the description proceeds, l0 mum number of parts, it being possible to readthe invention resides in the combination and arily assemble them. rangement of parts and in the details of con- Another object is m provide compresfor of struction hereinafter described and claimed, it this type which will not easily get out of order, being understood that changes may be made in and can be made at low cost. I the precise embodiment of the invention herein A still further object is to provide a compressor disclosed within the scope of what is claimed with- 15 which will operate eiliciently at a comparatively out departing from the spirit of the invention. slow speed, it being possible to obtain efiicient In the accompanying drawings, the preferred results from a six-inch rotor operating 'as low form of the invention has been shown. as 60 R. P. M. This is accomplished by increas- In said drawings, :0 ing to a maximum the sealing areas of the co- Figure l is a central longitudinal section acting wallsor worldng faces of the stator and through the compressor showing one of the imthe rotor without im osing excess frictional loads peller vanes broken away at the working space thereon and by constructing the rotor to func- 'of the stator;

tion as an inertia mass to counteract to an ap- Figure 2 is a section on line 2-2 of Figure 1; pr'eciable extent the retarding effect of fric- Figure 3 is a section on line 3-3 of Figure 1; 25

tional loads or drags imposed upon said areas by Figure 4 is a section on line 4-4 of Figure 3;

the impeller vanes and other frictional factors. Figure 5 is a view partly in edge elevation of the I have discovered that by making the face width compressor with parts of the stator in section; 'of the rotor relatively broad in proportion to the Figure 6 is a perspective view of one head of the so outside diameter of therefor and by iiiterposing stator:

said rotor between two fixed walls of the stator Figure '7 is a perspective view of the rotor; housing so that the side faces of the rotor are Figure 8 is a perspective view of the body porsubsta'ntially in cons tcontact with the respection of the stator showing the other head; tive inner faces of said fixed walls, the capacity Figure 9 is a perspective view of the rotor lookarea of the working chamber of the compressor nc toward t Opp te side thereof from that 3 remains constant, and in consequence thereof Shown n F gu uniform volumetric emciency is maintained. A F gu e 10 is a perspective view of one of the compressor of this class is purposely designed to impeller vanes. i give constant volumes per revolution of the rotor. er ng to the figures by characters of refer- 40 To obtain a reduced flow, it is to be understood n I designates a stator dy w h s p ef r- 40 that this can be accomplished by reducing th ably cylindrical. One end of the body is closed speed of the rotor. However, at any fixed speed by a head 2 which can be integral therewith and of the rotor, the discharge capacity of the comprovides a. bearing 2a for the shaft 3 Of the rotor. pressor remains constant due to the fact that the The other end of the body has an annular flange rotor is closely interposed between said fixed I, to which a removable head 5 is detachably se- 5 walls of the stator and, therefore, cannot move cured by means of bolts or other suitable devices, axially. The capacity remains constantalso beindicated at 6. This head is formed with an incause the width of the compressing space is not wardly offset portion 1 which forms an annular variable at any period in the rotation of said abutment, the ends 8 of which are inclined toward 5o rotor between the fluid'intake side of thestator the flat intermediate surface 9 of said portion 1, and the discharge side thereof. The intended the latter and said ends 8 representing approxihigh volumetric emclency from a six-inch rotor mately one-half the face area of that part of at an operating speed as low-as 60 R. P. M. is the head 5 which confronts the inner face of further made possible because of the manner, in head 2. One or more ports l0 can open through which the impeller vanes are mounted upon the each inclined or deflecting end 8 of the portion I, 66

and these can be in communication with pipes ll, one of which can constitute an inlet for fluid to be compressed while the other constitutes the outlet for the compressed fluid.

The removable head 5 has a socket l2 constituting an end bearing, the same disposed in axial alinement with the aforementioned bearing id for the shaft 3. Secured to this shaft between the heads 2 and 5 is a rotor l3, the .flat face l3a of which fits snugly against the fiat face 9 of the portion. 1. The hub 14 has a portion Ila which extends from said surface I3a of the rotor, the fiat face Nb of which abuts against the inner fiat face So of head 5, its periphery having a tight working fit against the inner arcuate surface Ia of said portion 1.

The rotor is provided with diametrically opposite slots l5 extending therethrough from the periphery of the rotor to a point inwardly of the periphery of the main body portion of the hub II, as shown in Figures 2 and 9. These slots are intersectedby a deep circular channel I6 formed in that face, of the rotor nearest the head 2. This ,channel is concentric with the rotor, provides a seat for a coiled spring l1 which bears at one end against the inner flat face 21) of head 2. and normally thrusts at its outerend against the inner end wall of the channel. Slidable within each of the slots I5 is a rectangular plate l8 constituting an impeller yane. Each blade extends from the inner wall of its slot outwardly to the periphery of the rotor and that end of the blade or vane nearest the head 2 is recessed at [9, so as to straddle the adjacent convolutions of the spring I]. Thus the one spring serves to hold both vanes normally pressed toward head 5. Consequently, as the rotor is operated, each vane will successively ride over one inclined terminal 9 of the abutment-forming portion 1, so as to place the spring under compression, then along the flat surface 9 of said portion, at which time the spring is further compressed, and subsequently down the other inclined'terminal 9 and along the sur-' face So of the head 5, the latter representing the other half of the face area of said part of the head which confronts the aforementioned inner face of head 2. During this movement of each vane, fluid in advance thereof will be expelled through the ports 10 first reached by the vane, and as the vane moves away from the other terminal of the abutment portion the fluid to be compressed will be sucked through the port or ports in said terminal and positioned behind the vane. By providing two vanes, as shown, a continuous stream of fluid can be delivered under pressure from the stator. It has been found, in practice, that a compressor constructed as described can be made at low cost and will operate emciently at a low speed and without overheating. Importance .is attached to the fact that the compressor is made up of very few parts and,

consequently, will seldom require repairs. All of the parts are readily accessible by removing the head 5, and in the event of excessive wear of the vanes, those parts can be easily removed without requiring the services of a skilled mechanic. a

. It will be appreciated, on reference to Figures 1, 7, 6 and 8, that the flat annular face 9 of the abutment portion I is disposed in parallel relation to the flat face lie of the rotor l3, and that the flat face lleand the flat face He at the opposite side of the rotor are parallel to the inner flat face In of the head 2. the said faces lie and Ne beingin the same vertical plane with each other. Upon particular reference to Figures 1 and 5, it will be observed that the peripheral face width of the rotor is co-extensive with the distance represented by a straight line from the face 9-to the face 2a and parallel to the horizontal axis of the rotor. It follows therefrom that said face I311 will constantly operate against the face 9, whereby to provide an effective fluid seal there-..

between and thus prevent fluid leakage between the portion of increased width of the working chamber of the stator and the portion of lesser width of said chamber. The portion of increased width will be herein referred to as the suction and pressure space.' The portion of lesser width which is wholly occupied by the wall thickness of the rotor, will hereinafter be referred to as the fluid-sealing space. It will also be observed that. during operation of the rotor and because of the manner in which the vanes are mounted, the inner transverse edges of the vanes will bear tightly against the smooth peripheral surface of the hub portion Ma, as will be appreciated on reference to Figure 1, thus sealing the space therebetween to. prevent leakage of fluid therethrough. The extension Ha of the hub is of smaller diameter than that of the main body portion of the hub,

and it will be appreciated, upon again referring to Figure 1. that the grooves i5 formed in said main body portion terminate at a point inwardly of the inner wall of the channel i6 ,'thus leaving. the extension Hla smooth as aforestated and as is necessary to a proper sealing of the space between same and the adjacent edge of the impeller.

Again referring to Figure 1, it will be observed that the left hand end of the lower one of the vanes l9 therein illustrated has been yieldingly advanced by the spring IT to an effective fluidcompressing position where its radial edge nearest the head 5 is in flat sealed contact with the large-area flat surface 50. of said head 5. The flat surface Nb of the hub is in fluid-sealed contact 'with the same flat surface 5a, where it is partly embraced by. the bearing surface la. In consequence of the employment of the means aforestated for sealing the vane, it will be further noted that on movement of the lower vane to the position just described, an effective seal is also established between the vane, the face 90. and

the inner wall of the stator, so as to prevent leakage of fluid past these lines. The seal thus formed and the seal formed in a somewhat similar manner by the companion vane of the rotor,

and the fact that the face width of the rotor is equal to the shortest width of the working space which separates the head I and face 9 from each other, and is broad relatively to the outside diameter of the rotor, are all contributing factors that co-ac't to provide a rotor construction in which all contact areas are well sealed. The form of the rotor is also such as to give it an inertia value sufflcient to counteract, to a considerable extent, the retarding frictional loads and drags imposed upon the contact areas. The construction is, further, such that the capacity area of the working chamber of the compressor will remain constant at all speeds so that uniform volumetric emciency is maintained at all times. The leakage line that would be expected to give rise to pressure losses in a compressor of this type would be bounded by the surface 9a, the confronting radial edge of the impeller vane that rides thereover, the outer edge of the same vane from a point'at the surface in to the flat face Ila of the rotor, and the inner edge of the vane where it that ts sides with time co-actins stator chine walls, it follows that the rotor held against movement axially of the stator. In view thereof, the

and give rise to losses in pressure and volumetric displacement would be at the face 9 and the adiacent radial edge of the impeller vanes which ride thereover.. As the rotor and stator are perfectly sealed at this last named point, no fluid can pass from the suction and pressure space to the aforementioned fluid sealing space, which is a further contributing factor toward maintaining a very high measure of efficiency and avoidingfluid pressure lossm.

I have stated that-the distance from the face 9 -to-theface Ibisequaltothe facewidth of the rotor. It follows that the vanes ll must, therefore, be co-extensive with the face width of the rotor so that they will be wholly containedwithin the slots of the rotor, when the vanes are acted upon by said face 9. width of the vane II is co-extensive, with the face width of the face 9 on any line passing across saidfacelradiallyoftheaxisoftherotor. This face l and the flat side l3a of the rotor.

The faces in and 9 are parallel'to each other, and they are also in different vertical planes, so

'as to allow for the intended maximum extent of movement of the vanes axially of the rotor and into sealed engagement with the face is of the head I. The low ends of the inclines I are in substantial alinement with each other and offset from a line drawn through the axis of rotation of the rotor, so that the vanes which are diametrically lines parallel to all surfaces thereof, which are radial to the axis of the rotor. Thisls anorder that the radial edges of the vanes which confront the head 5 will evenly contact with the inclines It follows also that the insures a proper sealing of the space between the opposite each other will approach the inclines on large extent against leakage, between the vanes and the co-acting contact surfaces of the head i. 5

Although this device has been described 98 F marily-for use as a compressor, it is also to be understoodthatitcanbeusedasaon unit.

What is claimed is: i0"

1. In a rotary pump. the, combination with at stator; a rotor; axially movable vanes on the rotor; and means on the stator for moving the vanes axially in one direction; of resilient means common to all the vanes for exerting a constant 15 force against them to move same axially in the opposite direction; and means for operatively mounting the resilient means. within the rotor. 2. In a rotary machine of the class described, a stator having a rotor chamber provided with a U concentrically. mounted rotor and said rotor having axially reciprocal vanes; cam means for moving the vanes axially in.one direction; and a coil spring mounted in the rotor concentric to the axis thereof and engaging all of the vanes 35 to move same in an opposite direction and against said cam means.

3. In a rotary machine of the class described, a stator having a cylindrical bore and oppositely disposed heads, one of said heads having a concentric abutment on its imi face, said abutment having terminal cam faces; a plurality of axially movable vanes carried by the rotor and adapted to co-act with said abutment, the width of each vane being substantially equal to the axial distance between the intermediate portion of the abutment and the other head, the cam faces coacting with the vanes to respectively cause and enable the vanes to approach and ride over the intermediate portion of the abutment and then leave same in rotation of the rotor; and a coiled spring mounted in the rotor concentrically thereof and provided with portions engasinz the vanes to constantly exert a yielding pressure thereagainst axially of said rotor and toward said r abutment.

GEORGE E. ROBERTS.

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