US2158933A - Rotary compressor - Google Patents

Description

-May 16, 1939. E, 50015 ROTARY COMPRESSOR 5 Sheets-Sheet 1 Filed July 26, 1937 May. 16, 1939. P. E. GOOD ROTARY COMPRESSOR 'Filed July 26, 1937 5 Sheets-Sheet 2 Ma 16, 1939. E. G000 ROTARY COMPRESSOR 5 Sheets-Sheet 3 Filed July 26, 1937 \M/ NW 5 Sheets-Sheet 4 P. E. GOOD ROTARY COMPRESSOR Filed July 26, 1937 May 16, 1939.

May 16, 1939. p

I ROTARY COMPRESSOR Filed July 26, 1937 5 Sheets-Sheet 5 Patented May 16, 1939 UNITED STATES PATENT OFFICE Ronny comaasson an E. Good, River-ton, N. J. Application July 26, um, semi No. 155,810 I v 18 Claims. (01. 230-150) v This invention relates to rotary compressors ior pumps, and more particularly to devices ofthis character such as illustrated in my prior Patent No. 1,989,552, granted January 29, 1935, for Rotary compressor.

The type of compressor illustrated in said patent comprises a rotor having a circumferential series of spirally directed grooves, a suitable casing surrounding said rotor and carrying and rotatably supporting a plurality of pistons having lobes to engagev said grooves and block the same from end to end as the rotor is rotated, and means in said casing defining intake and exhaust channels.

This structure, while admirably adapted to many uses in the compressor field, presents (iii-- ficulties in construction, and more particularly .in the production of housings and mountings for the rotatable pistoneiements and in the provision of the necessary intake and exhaust grooves.

An important object of the present invention is the provision of a structure such that the a construction such that the exhaust and intake channels may be -arcuately divided, thus materially simplifying the patterning and machining of the structure.

Another object of the invention is the production of a structure which lends itself readily to considerable modification such as the amplification or reduction of the number of barrier elements employed, to modification to enable fluids to be simultaneously pumped to several different points by the same compressor structure, and to the inclusion in the compressor structure of multi-stage compression.

-' These and other objects I attain by the-structure shown in the drawings wherein:

Fig. 1 isa vertical transaxial viewof a compressor constructed in accordance with my invention;

Fig. 2 is a section on line 2-2 of Fig. 1;

Figs. 3 and 4 areperspective views of the outer casing sections or barrier mountings;

Fig. 5 is a, perspective .view showing the rotor and cylinder combined:

Fig. 6 is a perspective view of the/rotor;

Fig. 7 is a diagrammatic vievv showing the gearing employed in driving the barriers when such is desired;

Fig. 8 is a perspective view of the assembled 6 structure;

Fig. 9 is a view partially in diametral section showing a multi-stage compressor constructed in accordance with my invention;

' Fig. 10 is a section on line ill-40 of Fig-9; 10

Figs. 11, 12 and 13 are views showing modified arrangements of the compressor casing structure;

Figs. 14, 15 and 16 are semi-diagrammatic views showing the barrier arrangements of the structures illustrated in Figs. 11 to 13 respectively;

Fig. 17 is a section on line il-ll of Fig. 12;

Fig. 18 is a modification of the arrangement shown in Fig. 17; and

Fig. 19 is a fragmentary sectional view similar 20 to that in Fig. 10 and illustrating a modified method of obtaining. reduced groove capacity.

Referring now to the drawings, and more particularly to Figures 1 to 8 thereof, wherein I have illustrated a compressor utilizing two grooves in the rotor and two symmetrically arranged barrier elements for coaction with said grooves, and a casing structure wherein the intake and exhaust of the grooves have common ports, the

numeral I0 generally designates a rotor comprising a shaft H and a rotor body I2 secured thereto, such rotor body having a truly cylindrical periphery provided with a series oif spirally extending grooves H which are symmetrically arranged thereabout so that the rotor body may remain in dynamic balance. An end of the rotor shaft is, in the present instance, illustrated as provided with a gear I 4, the purpose of which will hereinafter appear. Surrounding the rotor body is a cylinder. IS the inner surface of whichis 40 truly cylindrical and has a sliding fit with the periphery of the rotor. This cylinder is formed with slots I8 through which the lobes I! of the rotatable piston elements or barriers 18 are adapted to extend for engagement in the grooves I3. These slots, as originally formed, are somewhat wider and longer than the width and trajectory ot-the lobes, and have their margins kerfed as at It to provide an anchorage for a cast-in bearing-metal finishing piece 2|! which, in the final process isaccurately machined to accommodate the pistons.

Theexterior face or the cylinder is provided with ribbing 2| defining the slots l6 and with circumierential ribbings 22, 22a and 22b defining intake and exhaust channels 23 and 24 between adjacent ribbings 2 I. The exteriors of these ribbings are circumferentially smooth and are arranged upon a single truly cylindrical surface so that they may be conveniently finished by a simple machining operation. The ribs are formed with dowel notches 25 for the reception of inserted dowels 26 carried by the coacting casing sections now to be described.

The casing is formed in a plurality of sections, S, one for each barrier element I8 which is to be employed in the compressor, such sections each comprising an outer wall 21 having inwardly extending marginal ribbings 23 for engagement with the ribbings 22, 22b of the cylinder, a central rib 29 for coaction with the medial rib 22a of the cylinder, and transverse ribbing 30 for coaction with the ribbing 2|. In the assembled relation of the casing sections, the ribbings 22, 22a, 22b and 28 and 29 combine to produce annular channels. The sections ofv these channels which, in the form at present under discussion, lie at opposite sides of the ribbings 2| and 30, are placed in communication with one another by transfer ports 3|, 3|a formed by abbreviation of the ribbings 30 of the casing elements and the connection of these ribbings by a web 32. Since the'outer surface of the ribbing of the cylinder presents a truly cylindrical surface, it is simply necessary, in order that a proper clamping flt between the casing sections and cylinder be provided, that the sections forming the casing be bolted together as by bolts 33 extending through openings 34, and accurately bored to the desired diameter.

By utilizing this construction, the formation of cores necessary to the production of intake and exhaust ports 35 and 36, the intake and exhaust channela'and the housing for the barrier elements is greatly simplified. Furthermore, as will behereinafter more fully brought out, the construction just recited is particularly advantageous in that by a simple modification of the core structure necessary in the formation of the casing elements, the ports 3| may be blocked,

. thus enabling segregation of the intake or exhaust, or both, for any section or group of sections in the compressor structure. This variation of the structure will be discussed more fully hereinafter in connection with Figures 12, 15, 17 and 18. Additionally, the separate formation of the cylinder permits ready variation of the pattern to control the size of the ports where fixed ports are to be employed, and the cylinder wall proper is always readily accessible for machining to form valve seats where such are to be employed as described in my prior patent hereinbefore mentioned.

, In order that the pistons l8 may be conveniently mounted in the casing sections, I form in each section which isto mount a piston a straight bore 31 considerably larger than the shaft 38 mounting the piston, as more clearly shown in Fig. 1. This bore intersects the ribbing 30 of the casing section and partially interrupts the inner periphery of the same. Within the bore, I arrange bushings 39 and 40, these bushings, upon insertion, projecting into the interior of the casing section and interrupting the inner periphery of the same prior to the machining operation by which-they are given the same cylindrical contour as the casing sections and the periphery of the cylinder, Dowels 4|, or some similar expedient, may be employed for locating the bushings, and the bushing 40 is utilized as a support for a sealing packing 42 and the bearing 43 for the shaft. The bushing 39 is, as illustrated, utilized solely as a support for a sealing packing 42a, the corresponding end of the shaft 38 being supported through a bearing 44 mounted in an end closure bushing 45 having a removable cap plug 46 through which access may be had to the end of. the shaft and to the lock pendicularly related bore 49. which is similarly closed, and the closure plates 48 and 50 when removed afford access to the driving connection between the shafts 38 and perpendicularly related shafts 5|, the outer ends of which are connected with the gear l4 of the rotor shaft through gearing 52, as suggested in Fig. 7. This gearing, as more clearly shown in Figure 2, may be conveniently housed by an oil-tight cover plate 53 secured to the housing sections. The piston' housings are preferably provided at the outer wall of the associated casing section with inspection openings 53a closed by plates 53b; these openings will permit the condition of the piston tobe examined at any time without the necessity for dismantling the compressor.

As a means for securing proper centering of the rotor and cylinder and holding the casing against axial displacement, and as a means for conveniently supporting the rotor, end plates 54 are utilized, these plates being secured to thecylinder wall and slightly overlapping the casing sections as indicated at 55. The plates have additionally an inwardly extending annular boss 56 interiorly fitting the cylinder and are formed centrally with openings 51 for the reception of bearing mounts 58 mounting bearings 59 for the shaft ll of the rotor. Inwardly of the bearing platesthe bosses are constructed to mount oppositely facing sealing packings 60 and 6| which serve respectively to exclude lubricants necessary to the bearings .58 from the interior of the casing and to seal against the outward passage of air about the rotor shaft.

The construction just described, obviously, lends itself readily to considerable modification without departing from the principles utilized therein. In Figures 9 and 10 I have illustrated this construction as applied to a multi-stageoperations and assembly are concerned, the struc-.

ture remains identical with the structure originally described.

In the form at present illustrated, in addition tothe' supply and exhaust ports 61, 68 for intake and exhaust channels 23, 24, a take-off port 58 may be provided for the channel 66 through which a portion of the first stage of compression may be removed as desired. It will, of course,

be understood that, under these circumstances, the intake end of the compressor will have at capacity exceeding that of theexhaust end by the amount of fiuid which it is desired to remove'at.

port 69. In the simple form of this structure the relative capacity of these sections will be such thatthe fluid as compressed in the first or intake section is Just sufiicient to supply the grooves of the secondary exhaust section. It will be also noted from these figures that barriers or pistons having a different number of lobes may be employed; the illustration showing. the intake section as employing'a four-lobe barrier and thereadily obtained by internally increasing the thickness of the cylinder wall and correspondingly reducing therotor diameter as suggested in Figure 19. r

A characteristic end elevation of the structures of Figs. 1 to 10 is shown in Fig. 11, and in Fig. 14 I have diagrammatically illustrated the barrier piston arrangement employed therein.

In Fig. 12 I haveiilustrated the use of a greater number of casing sections, each supporting a barrier, four being illustrated in the present instance, as'indicated in the diagrammatic showing of Fig. 15. In this figure 1 have, likewise, illustrated an arrangement whereby fluids may be simultaneously pumped to different destinations in desired quantities. This is accomplished, as hereinbefore briefly noted, by blocking the port 3| or Ila, or both, in certain of the casing sections. In Fig. 17 a sectional view of the casing section is given, taken immediately adjacent the barrier casing. It will be noted that no by-pass ports 3| or 3| a are employed, and since the arrangement illustrated in Figure 17 is common to both' barriers on the diameter A-.-A the structure illustrated in reality comprises two separate compressors arranged on opposite sides of the diameter A-A, such compressors having a common rotor. Each section A or B may then be provided with an individual intake 10 and exhaust H. By suitably varying the number of sections, the desired proportions pumped by either compressor section may be determined. If desired, a multiplicity of minor sections such as A and B may be provided and these given a common intake by simply utilizing the intake by-pass 3| and blanking oi! the exhaust by-passes as suggested in Fig. 18.

In some instances, it may be desirable to employ an arrangement such as shown in Fig. 13 which diagrammatically illustrates a compressor structure, which could be readily employed as a' supercharger for an engine the base or underlying support of which would not permit the use of a casing section at the lower portion of the compressor body. Under these circumstances, barriers may be grouped as suggested in Figure 16 and a section I2 employed which simply blanks off the space provided for an additional section.

tial channel and a radially directed axially disposed slot, the outer faces of said ribs being disposed upon a common diameter, a casing element closing the channel and combining with that portion of the ribbing defining the slot to produce a piston housing, a rotary piston in and carried by said housing element having lobes meshing in said rotor grooves and successively blocking said grooves'fromend to end as the rotor is rotated, and means to supply fluid to said grooves, the inner wall of the channel having an exhaust port adjacent one face of the ribbing defining the slot and the channel having a delivery port.

2. In a rotary pump of the type described, a rotor having an annular series of spirally extending grooves, an annulus surrounding the rotor and having external ribs defining a plurality of circumferentially spaced radially directed axially disposed slots and between said slots circumferentially extending channels, the outer faces of said ribs being disposed upon a common diameter, casing elements closing the channels and combining with those portions of the ribbing defining the slots to produce piston housings, a rotary piston in each housing and carriedby the associated casing element, said pistons having lobes meshing in said rotor grooves and successively blocking said grooves from end to end as the rotor is rotated, and means to supply fluid to said grooves, the inner wall of each channel having an exhaust port adjacent one face of the ribbing defining the slot and means to deliver fluid from the channels.

3. In a rotary pump of the type described, a rotor having an annular series of spirally extending grooves, an annulus surrounding the rotor and having external ribs defining a plurality of circumferentially spaced radially directed axially disposed slots and between said slots circumferentially extending chanels, the outer faces of said ribs being disposed upon a common diameter, casing elements closing the channels and combining with those portions of the ribbing defining the slots to produce piston housings, a rotary piston in each housing and carried by the associated casing element, said pistons having lobes meshing in said rotor grooves and successively blocking said grooves from end to end as the rotor is rotated, and means to supply fluid to said grooves, the inner wall of each channel having an exhaust port adjacent one face of the ribbing defining the slot, ports in said casing-elements placing the channels in communication with one another and a delivery port in one of said casing elements. v

4. In a pump of the type described, a rotor havinga circumferential series of spirally disposed grooves, an externally cylindrical cylinder surrounding and fittingthe rotor, complementary segmental casing sections clamped about said cylinder and rotatable pistons carried by at least some of said casing'sections and having lobes to engage in said grooves and successively block said grooves from end to end as the rotor is rotated, said cylinder having axially-directed radial slots for the passage of the lobes of said pistons, and ribbing on said casing sections including axial ribbing defining the slots of the cylinder and providing a housing for the associated piston and circumferential ribbing defining an exhaust channel, said ribbings having their circumferential faces disposed upon a common diameter and having operative sealing engagement with said cylinder, and said cylinder having an exhaust port adjacent each of said slots.

5. In a pump of the type described, a rotor having a circumferential series of spirally disposed grooves, an extemally-cylindrical cylinder surrounding and fitting the rotor, complementary segmental casing sections clamped about said cylinder and rotatable pistons carried by at least some of said casing sections and having lobes to engage in said grooves and successively block said grooves from end to end as the rotor is rotated, said cylinder having axially-directed radial slots for the passage of the lobes of said pistons, and ribbing on said cylinder including axial ribbing defining the slots and in part providinga housing for the associated piston and circumferential ribbing defining an exhaust channel, said ribbings having their circumferential faces disposed on a common diameter and having operative sealing engagement with said casing sections and said cylinder having an exhaust adjacent each slot.

6. In a pump of the type described, a rotor having a circumferential series of spirally disposed grooves, an externally cylindrical cylinder surrounding and fitting the rotor, complementary segmental casing sections clamped about said cylinder and rotatable pistons carried by at least some of said casing sections and having lobes to engage in said grooves and successively block said grooves from end to end as the rotor is rotated, said cylinder having axially-directed radial slots for the passage of the lobes of said pistons, and complemental ribbing on said cylinder and casing sections comprising axial ribbing defining the slots and providing a housing for the associated piston and circumferential ribbing defining an exhaust channel, said ribbings having their circumferential faces disposed on a common diameter and having operative sealing engagement with one another.

.7. In a rotary pump of the type described, a rotor having an annular series of spirally extending grooves, an annulus surrounding the rotor and having external ribs defining a plurality of circumferentially spaced radially directed axially disposed slots and between said slots circumferentially extending channels, the outer faces of said ribs being disposed upon a common diameter, casing elements closing the channels and combining with those portions of the ribbing defining the slots to produce piston housings, a rotary piston in each housing and carried by the associated casing element, said pistons having lobes meshing in said rotor grooves and successively blocking said grooves from end to end as the rotor is rotated, and means to supply fluid to said grooves, the inner wall of each channel having an exhaust port adjacent one face of the ribbing defining the slot, ports in said casing elements placing the channels in communication with, one another, a delivery port in one of said casing elements, and ports in certain of said casing sections placing the channels at opposite sides of the associated rotary piston in communication with one another, the remaining casing elements constituting dams defining the ends of the channels. 1

8. In a pump of the type described, a rotor having a circumferential series of spirally dis-- posed grooves, an externally cylindrical cylinder surrounding and fitting the rotor, complementary segmental casing sections clamped about said cylinder and rotatable pistons carried by at least some of said casing sections and having lobes to engage in said grooves and successively block said grooves from end to end as the rotor is rotated, said cylinder having axially-directed radial slots for the passage of the lobes of said pistons, ribbing on said cylinder including axial ribbing defining the slots and in part providing a housing for the associated piston and circumferential ribbing defining an exhaust channel, said ribbings having their circumferential faces disposed on a common diameter and having operative sealing engagement with said casing sections and said cylinder having an exhaust port adjacent each slot, and ports in certain of said casing sections placing the channels at opposite sides of the associated rotary piston in communication with one another, the remaining casing elements constituting dams defining the ends of the channels.

9. The structure of claim 2 wherein the casing elements have complemental ribbing sealingly engaging the ribbing of the annulus.

10. A device as claimed in claim 1 wherein the portions of the channel at opposite sides of the rotary pistons are in communication with one another.

11. A device as claimed in claim 1 wherein the portions of the channel at opposite sides of certain of the rotary pistons are in communication with one another and are segregated from the remaining portions of the channel.

12. In a rotary pump of the type described, a rotor having a pair of annular series of spirally extending grooves, the grooves of one series having lesser capacity than the grooves of the other series, an annulus surrounding the rotor and having external ribbing defining two circumferential channels and radially directed axially ,disposed slots in alignment with each of said groove series, the outer faces of said ribs being disposed upon a common diameter, casing elements closing the channels and combining with those portions of the ribbing defining the slots to produce piston housings,rotary pistons in and carried by said housings having lobes meshing in the grooves of each series and successively blocking'said grooves from end to end as the rotor is rotated, means to supply fluid to saidgrooves, the inner wall of one channel having exhaust ports for cooperation with one series of grooves and intake ports for cooperation with the other series of grooves, the inner wall 'of the other channel having exhaust ports for cooperation with the last-named series of grooves.

13. In a rotary pump of the type described, a

rotor having a pair of annular series of spirally extending grooves, the grooves of one series having lesser capacity than the grooves of the, other series, an annulus surrounding the rotor and having external ribbing defining two circumferential channels and radially directed axially disposed slots in alignment with each of said groove series, the outer faces of said ribs being disposed upon a common diameter, casing elements closing the channels and combining with those portions of the ribbing defining the slots to product piston housings, rotary pistons in andcarried by. said housings having lobes meshing in the grooves of each series and successively blocking said grooves from end to end as the rotor is rotated,

means to supply fluid to said grooves, the inner wall of one channel having exhaust ports for cooperation with one series of grooves and intake ports for cooperation with the other series of 2,158,988 responding to that of the reduced portion oi. the

rotor. 14. A device as claimedin claim 12 wherein the casing sections have ribbing complemental to the ribbing oi the cylinder and in sealing engagement therewith.

' 15. A deviceas claimed in claim 3 wherein the portions of each channel at opposite sides of certain of the rotarypistons are in communication with one another and are segregated from the remaining portions of the channels.

16. A device as claimed in claim 4 wherein the portions of each channel at opposite sides of certain of the rotary pistons are in communication with one another and are segregated from the remaining portions of the channel.

17. A device as claimed in claim 3 wherein the channels at opposite sides of the rotary pistons are in communication with one another.

-18.'A device as claimed in claim 4 wherein the channels at opposite sides of the rotary pistons are incommunication with one another.

PAUL E. GOOD.

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