US2663492A

US2663492A - Air cooled air compressor

Info

Publication number: US2663492A
Application number: US262748A
Authority: US
Inventors: Arthur C Eaton
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-12-21
Filing date: 1951-12-21
Publication date: 1953-12-22
Anticipated expiration: 1970-12-22

Description

Dec. 22, 1953 A. c. EATON 2,663,492

AIR COOLED AIR COMPRESSOR Filed Dec.

5 Sheets-Sheet 1 Dec. 22, 1953 A. c. EATON 2,663,492

AIR COOLED AIR COMPRESSOR Filed Dec. 21, 1951 5 Sheets-Sheet 2 86 Mm V A Ilornry Dec. 22, 1953 A. c. EATON 2,663,492

AIR COOLED AIR COMPRESSOR Filed Dec. 21, 1951 5 Sheets-Sheet 3 Inn mm- AMTHUI CiE/ITJN A. C. EATON AIR COOL-ED AIR COMPRESSOR Dec. 22, 1953 5 Sheets-Sheet 4 Filed Dec. 21, 1951 n 1 IV. 5 g

152 Jiqi s Jfe AFTHURC. EATON- Dec. 22, 1953 A. c. EATON AIR COOLED AIR COMPRESSOR 5 Sheets-Sheet 5 Filed Dec. 21, 1951 Nmw ARTHUR c, E4TON [iv Hz- Half.

' e e win are 1 Figure 4 being; on i Patented Dec. 22, 1953 iJNiTED STATES FATENT OFFICE 14 Claims.

This invention relates to a novel form of air cooled air compressor of the rotary type including. an encased revolving rotor by means of which air is compressed for supplying a storage tank with compressed air or for supplying air to other devices operated by compressed air and wherein the air is initially utilized by the compressor due to the rotary movement of the rotor for cooling said rotor and the parts carried thereby.

Another object of the invention is to provide an air compressor having a revolving rotor functioning similarly to a flywheel and having cam actuated compressing means carried thereby and actuated by the rotation thereof for compressing air as the rotor is revolved.

Another object of the invention is to provide an air compressor wherein the air is supplied under pressure to the compressing means eliminating the necessity of drawing the air by vacuum thereto thus increasing the capacity of the compressing means, due to the fact that the air is under pressure at the commencement of the compression stroke.

A further object of the invention is to provide a novel cam means for actuating the air compressing means and which is adjustable automatically in response to the air pressure within a tank or container supplied by the compressor to cause the cam means to assume an inoperative position to prevent operation of the compressing means when the pressure in the storage tank reaches or exceeds a maximum capacity.

A further object of the invention is to provide a compressor having novel means responsive to an excess pressure of air in a storage tank automatically rendering the compressor inoperative until the air pressure in the storage tank is diminished.

Still a further object of the invention is to provide an air compressor having a novel lubricating means to maintain its supply of lubricant under pressure to the moving parts thereof at all times while the compressor is in operation.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating presently preferred embodiments thereof, and wherein:

igure 1 is a longitudinal central sectional view, partly in side elevation illustrating one preferred embodiment of the invention;

Figures 2, 3 and 4- are cross sectional views thereof taken substantially along planes as in- 2 3- 3 and i -:4 of Figure Figure 5 is an enlarged fragmentary longitudinal sectional view of a portion of the compressor;

Figure 6 is an enlarged end elevational view of a portion of the compressor;

Figure 7 is an enlarged fragmentary longitudinal sectional view partly in elevation of one of the compressor pistons;

Figure 8 is an end elevational view thereof looking from left to right of Figure 7;

Figures 9 and 10 are cross sectional views of the piston rod and piston, respectively, taken substantially along planes as indicated by the lines 9--;) and !0Hl, respectively, of Figure 7;

Figure 11 is a view similar to Figure 4 looking toward the inner side of the cam end of the compressor casing showing one modified form of cam structure;

Figure 12 is a vertical sectional view taken substantially along a plane as indicated by the line l2--l2 of Figure 11;

Figure 13 is an enlarged fragmentary plan view of a portion of one of the cam elements;

Figure 14 is an end elevational view thereof as viewed along the line i il4 of Figure 13;

Figure 15 is a view similar to Figure 11 illustrating another modified form of variable cam;

Figure 16 is a cross sectional view thereof taken substantially along a plane as indicated by the line [6-16 of Figure 15;

Figure 17 is a view similar to Figure 15 illustrating still another form of variable cam;

Figure 18 is a sectional view thereof taken substantially along a plane as indicated by the line lB-Ifi of Figure 17;

Figure 19 is a view in the same plane as Figure 18 but showing the cam in an elevated, operative position as distinguished from its inoperative position as illustrated in Figure 18;

Figure 20 is a top plan view of one element of the cam of Figures 17, 18 and 19;

Figure 21 is an edge elevational view thereof, and

Figure 22 is a fragmentary side elevational view showing one form of a pressure actuated switch for use with the cam structure of Figures 1 to 10.

Referring more specifically to the drawings, first with reference to Figures 1 to 10, the novel compressor in its entirety is designated generally 25 and includes a casing or housing, designated generally 25 which is composed of a side wall 2'5, which is preferably cylindrical, and end walls 28 and 29v pending foot members; 30 on whichihe-housing and hich ay The side wall 21 is provided with def secured to a supporting surface, not shown, for maintaining the 2s stationary.

A stationary shaft 3! extends inwardly through the central portion of the end wall 28 and terminates intermediate of the ends of the casing 26 and is disposed axially thereof. Said stationary shaft 2| being provided with a head 32 at its outer end to secure it to the outer side of the end wall 23 by a suitable fastening 33. A rotor, designated generally 36 is journalled on the stationary shaft ill and is disposed for rotation in the casing 23, the bore 35 of said rotor which turnably engages the shaft 3| being provided with enlarged ends 36 and 13! to accom! mcdate tapered antifriction bearings v38 and 19,

respectively, which are disposed therein and in engagement with the shaft .31. The bearing 59 which is located adjacent the head or end 28 abuts against an adjustable collar 413 secured to the shaft 3! to prevent the rotor 34 from sliding toward said end 28.

A driven rotary shaft l! extends axially into the casing 25 through the end wall 29 .and is journalled therein by a tapered antifriction'bearing unit 42 which seats in an inwardly opening recess 63 of the Wall 29. The wall 29 on its outer side is provided with a stuffing box 44 surrounding a portion of the shaft ll. The shaft ii is provided with an enlargement 45 which bears against the bearing 62 to prevent the shaft 3:)

from being displaced outwardly through the wall 29. The inner flanged end 56 of the shaft 41 is secured by fastenings ill to one end of a coupler as, the opposite end of which is secured by fastenings 59 to the end of the rotor 35 in which the anti-friction bearing unit 33 is mounted, so that the collar so and enlargement l5 combine to prevent sliding movement of the rotor 34 in either direction on the stationary shaft 3i and the bearing units 39 and 42 form thrust bearings which are engaged by the collar 49 and enlargement 45, respectively.

The rotor 34 has an annular outwardly extending flange 513 located adjacent the end of its central or hub portion 5! in whichthe recess 37 is formed and which flange 5B is provided adjacent its periphery with an annular flange 52 which projects at a right angle to the plane of the flange 5c and toward the end wall '29.

The flange or wall 58]. and the annular peripheral b flange 5-2 of the rotor 3 4 combine to form an annular chamber 53 surrounded by the peripheral flange 52; and which is disposed between said flange and the oppositelend of the hub 5|, which is secured to the coupling 48. Said annular chamber 53 opens toward the end wall 29. The peripheral flange 52 is provided with two diametrically opposed internal enlargements 5d on its inner side which are disposed within the chamber 53, forming cylinders 55 which open toward the end wall 29. The outer surface of the peripheral flange 52 and the contiguous peripheral edge of the wall 50 are provided with spaced annular ribs or enlargements 56 and 5'! tively wide radially fits on the peripheral edge b e l 5t with portion .01 one s de thereof wh is located adjacent its inner .edge abutting aaeainstth adjacent side of th annul r .rib 56 and to which the ring 58 is secured by circumferentially spaced fastenings 59. If desired, the

ring 58 may be formedintegral with the wall v as extending therearound. A ring 58 which is rela- .50 ;c. outer outer side of the ring 58 are each preferably provided with cooling fins 60.

A plurality of corresponding vanes 61 are mounted on the

shoulders

56 and 51 in circumferentially spaced relationship to one another, each of said vanes 6| being curved in the same direction from its inner to its outer edge and having an arcuately bowed flange projecting from the convex side of its inner edge and which is likewise arcuately bowed transversely. Said flanges 62 have their end portions resting on the shoulders 55 and 51 and the flange 52 of each vane 6| extends to adjacent the concave side vof the next trailing vane 6i to provide a restricted slot 53 therebetween. Each of the flanges 52 is connected to each of the shoulders 56 and '51 by at least one fastening St. The flanges combine with the

shoulders

56 and 57 and with the portion of the exterior surface of the annular peripheral flange 52, located between said shoulders, to form an annular chamber having the outwardly opening slots 63 and which is provided with two inwardly extending passages 165 which extend inwardly from said annular chamber 66 and one of which opens into an annular internal enlargement 67 of each of the cylinders 55. A second relatively wide ring 68 is disposed on the outer end of the outer surface of the peripheral flange 52 and against the outer side of the other shoulder 5'! and said rings '58 and 68 extend outwardly to the outer edges of the vanes BI and to adjacent the inner surface of the cylindrical wall 21 and combine with said vanes to form air scoops for deflecting air inwardly through the slots 63 into the annular chamber 55, when the rotor 34 is revolved in a direction so that the outer edges :of the vanes Si constitute their leading edges, or counterclockwise as seen in Figure 2. It will likewise be readily apparent that the vanes 6! may be secured in reversed positions to function :in the same manner when the rotor is revolved in the opposite direction or clockwise as seen in Figure 2.

As illustrated in Figures '1, 2 and 4, the cylindrical wall 2! is provided with spaced annular external ribs 69 on which is disposed an annular band or strip lo which is secured by fastenings ll adjacent the side edges to the peripheries of the ribs 69 to combine therewith and with the portion of the cylindrical wall 21 which said band surrounds to form an annular outer air chamber 12. Said wall portion is provided with a plurality of circumferentially spaced longitudinally extending slots 13 which communicate with the chamber 72 and which open into the interior of the casing 25 between the

rings

58 and 68. The band 70 is preferably provided with two air inlet conduits M which open downwardly into the chamber 12, as best illustrated in "Figure 2, each of which is preferably provided at its upper inlet end with an air filter 15 for f ltering the air entering the casing 26.

The stationary shaft 3! is provided with an annular groove lfi in its periphery which is connected by radial passages l? to one end of a longitudinal passage 18 of the shaft 3!, and the opposite end of which opens outwardly through the head 32 and is in communication with a conduit 553 which is tapped into said end of the passage 18. The conduit 19 is adapted to communicate at its opposite end with any suitable air storage tank 80, such as illustrated in Figure 22 or with any other suitable device adapted to be lie tn'oroperatedcylinders 55 are provided with restricted seats 85 at their inner ends which open into cavities 82 formed in the rotor wall 50, each of which cavities has a bore 83 extending radially inward therefrom into the hub bore and which communicates with the groove 76. A valve housing 8 5 has an enlarged flanged end 85 seating in each seat 8! and projects therefrom into the adjacent cavity 82. Each housing 84, as best seen in Figure 5, has a bore 81'; extending longitudinally therethrough provided with an enlarged externally threaded outer end 57! which opens into the cavity 82 and a restricted inner end 83, defining a valve seat which opens into the cylinder 55. A perforated valve stem guide and spring seat 89 is threaded into the bore end 3? to slidably guide the stem iii) of a valve 9! which seats in the valve seat 88 and against which bears an end of a spring $2 mounted on the stem 9!] and having its opposite end abutting the seat guide 89.

Each cylinder 55 has a liner or sleeve 93 disposed therein which abuts a portion of the housing head $5 in the same cylinder for retaining said head against the seat 3!. Each sleeve $3 is provided with a series of circumferentially spaced openings M which open into the groove 6?. A piston 95 is reciprocally mounted in each sleeve 93 and has a piston rod 96 extending therefrom reciprocally through a guide 97 which is provided with a flanged head @8 which closes the open end of its associated cylinder 55 and which is secured by fastenings 92 to the end of the enlargement forming said cylinder. The heads 98 likewise retain the sleeves $3 in seated positions and tightly against the housing head 35.

As seen in Figure 1, an annular internal wall ill!) is secured in liquid. tight engagement around a part of the inner surface of the cylindrical wall 27 between the rotor 3- and end wall as. The inner edge of the wall ice is spaced a sub stantial distance from the longitudinal center of the casing 26. The guides S! are provided with grooves it}! which fit the inner edge of the wall N30. The bottom portions of the walls 23 and we combine to form a sump or storage chamber for oil, as seen at E2 in Figure 1. It will also be noted that portions of the guide heads $38 overlie the outer surface of the peripheral flange 52 and abut against the outer side of the ring memher 56 to retain said ring member on the flange E2 and against the outer side of the rib 5?.

Each piston rod is provided with a wheel fork its its opposite end in which is journalled wheel or roller Hi l which is disposed to ride on the inner surface or" the wall 28 in a circular path when the rotor 3 is revolved and said wall 29 is provided on its inner side in the path of travel of the rollers i535 with two arcuately or circumferentially extending cam groove H35 the beds of which are inclined upwardly and toward the inner surface of the wall it in a counterclockwise direction from end-to-end thereof so that as the rollers EM travel about the inner surface of the wall 25, each roller in moving counterclockwise will simultaneously be displaced by a spring l .35 into the deep end of a cam groove Hi5 and in traveling counterclockwise will roll up the inclined bed of said groove back onto the surface of the wall 28, each roller tell engaging each cam groove 1% during each revolution thereof to cause each of the pistons 95 to make two complete strokes in each revolution of the rotor 3 The springs MG are mounted on the piston rods between the outer ends of the guides 9"? and the forks H33.

Each piston rod 95, as best seen in Figure 7, is threaded into one end of a bore I01 which extends through the piston ilE and said piston rod carries a lock nut I88 which is threaded thereon and abuts against the outer end of the piston. The opposite end of the bore It? is provided with a valve seat its for an outwardly opening valve iii which seats thereagainst and has a valve stem l i extending inwardly of the bore ill! from the valve il through a perforated guide H2 in which said stem is reciprocally mounted for guiding the movement of the valve H2. The guide l 12 is threadedly mounted in the bore Hi? between the valve seat i as and the adjacent end of the piston rod An expansion spring I !3 car ried by the valve stem Ill normally retains the valve H8 in a seated position. The piston is provided with a plurality of air passages EM which open into the intermediate portion of the bore ill! and outwardly of the rear face of the piston 95. The periphery of the piston 3-5 is provided with spaced piston rings E E5.

A gear H6 is disposed around the end of the hub 55 located adjacent the coupling 43, and is preferably formed integral therewith and meshes with a pinion ill fixed to a shaft H8 which drives a pump 5 is. The pump H9 is disposed between the rotor 3t and end wall 2e, adjacent the of the casing 25 and is supported by a bracket lii secured to the inner side of the end wall An inlet conduit l2! has an inlet end opening into the sump or oil reservoir I82 through the cylindrical wall 2. and has an opposite end tapped into the inlet side of the pump H9, said conduit lZl having a portion disposed externally of the casing 255, as illustrated in Figure 1, including a bore l22 extending through the wall 29. An outlet conduit 12% has one end tapped into the outlet side of the pump H9 and has its opposite end tapped into the stationary shaft head and communicating with a passage li 'l which extends longitudinally of said head and of the shaft 35. The conduit I23 extends along the underside of the casing 26 and along portions of the ends thereof, as seen in Figure l, and includes a bore portion 525 extending through the end wall 29, adpacent the bearing 32 and has a branch port iZE opening into and lubricating the bearing 22. The annular groove it of the shaft Si is located between two annular grooves till, formed in a periphery of said shaft 3!, each of which contains a plurality of split rings i223, the split portions of which are disposed out of registry to provide a substantially solid annular band or ring, The lubricating passage 52d has branch ports I29 for lubricating the rin s of each groove 12'! and branch port 539 for lubricating the other thrust bearing 89. The other end of the passage {2 t opens into an annular uoove iii! in the periphery of the shaft 3i which is located adjacent the bearing 38 and which groove communicates with radial ports 132 of the hub 5i, to each of which is connected an end of a lubricating conduit 533. The opposite ends of the oonduitsltt are tapped. into the outer ends of radial passages 53-4, as best seen in Figures 1 and 5, the inner ends of which passages lubricate the bores of the guides ill, in which said passages are formed for lubricating the piston rods ea. As seen in Figure '7, each piston rod 95 has a longitudinally extending lubricating passage #35 including a radial branch passage its by means of which the :lubricant 'IOZis supplied to the "passage I35 from the passage I34 of the guide 97 in which said piston rodQB is reciprocally disposed. One end :foregoing it will be readily apparent that when the rotor which with the vanes or scoops 6| forms a turbine wheel, is revolved, the pum H9 will be actuated for pumping oil I02 from the reservoir as seen in Figure 1 through the pipes or conduits I2! and I23, through the passage I24 and conduits I33 for lubricating the rotor bearing and other parts of the rotor which engage the stationary shaft SI and for also lubricating the pistons 95, piston rods 96 and the wheels or rollers I53.

Assuming that the drive shaft M is being revolved as by means of an electric motor, not shown, it will be readily apparent that the rotor turbine wheel 34 will be rotated at the same speed as said drive shaft by being connected thereto by the coupling is and will turn on the stationary shaft 3i. As said turbine wheel is revolved, the vanes or scoops 6i turning counterclockwise'as seen in Figure 2 will create a suction in the outer annular chamber 12 to cause air to be drawn into said chamber through the air-intakes It provided with the filters 15. The air will be drawn from said annular chamber 12 by the scoops 6| inwardly through the ports 73 into the turbine wheel pockets formed by the vanes or scoops BI and the

rings

58 and 63. The air impinging against the forward, concave sides of the scoops will be deflected inwardly through the restricted slots 63 into the inner annular air chamber 56 in which chamber the air will be compressed and forced under pressure radially inwardly through the passages 55 into the annular grooves 67 of the two cylinders 54 from which the air will escape under pressure through the sleeve openings 9 into the interior of the sleeves 93.

Asthe turbine wheel 34 is revolving to thus charge the cylinder sleeves 93 with compressed air, the wheels or rollers 54 will be riding the inner surface of the end wall 29, as best seen in Figure 3, in a counterclockwise direction and as each roller 9e reaches each of the cam grooves I05 it will be projected by its spring I58 into the bed of said groove at its deepest end, thereby allowing the two springs I9 5 to simultaneously move the pistons 95 to their retracted positions of :Figure 1 adjacent the guides 9i and so that the openings 9-: will be exposed to the left of the pistons 95 for fully charging the cylinder sleeves 93 between the pistons 85 and the cylinder heads 85. As the turbine wheel continues to turn counterclockwise, the rollers its will ride up the inclined bottoms of the cam grooves I05 and during their initial travel therealong, the pistons '95 will be displaced to the left for initially closing the ports or openings 94 and for thereafter further compressing the air between the pistons and cylinder heads 85. This will cause the valves 9| to be opened to allow the air to escape through the bores 83 and guides 89 into the cavities 82, through the radial pas- 8 sages into the annular groove 15 of the shaft 3| thence through the passages 11 into the passage I8. The compressed air will pass through the passage I8 and conduit I5 into the storage tank 86, as seen in Figure 22. As each piston moves to the left past the openings 94, additional air will be forced into the sleeves 93 behind or to the right of the pistons 95, as previously described, to fill said sleeves with compressed air to the right of the projected pistons 95. When the rollers I56 have completed a half revolution and each drops into the other cam groove I05, the pistons 95 will again be retracted by the springs I06 and return to their positions of Figure 1 and in so moving from left to right, the compressed air to the right of the pistons will flow from right to left through the passages Hi and bores I61, and through the guides M2 to unseat the valves III] to allow the compressed air to escape to the opposite or left hand side of each piston. The cylinder sleeves will thus be initially charged with air during substantially the entire return stroke of each piston and will be further charged with compressed air as the pistons pass to positions to the right of the openings 94, as previously described. It will be understood that each piston 95 executes two compression strokes and two return strokes for each revolution of the turbine wheel 35. If desired, it will be readily apparent that four equally spaced cylinders and pistons can be provided in lieu of the two cylinders 54 and two pistons 55 and in which case either two or four cams ")5 could be provided, depending upon the amount of air required; however the two compressor cylinders with the two cams is equal to a four cylinder compressor and is capable of compressing more air than a four-cylinder compressor having cylinders of the same size due to the compressing of the air in the cylinders on the backstroke of the pistons rather than having air drawn into the pistons by suction, as is conventional and which causes a vacuum to exist in the conventional cylinder as the piston thereof starts its compression stroke,

Any suitable automatic switch means may be utilized for de-energizing the electric motor by means of which the shaft M is driven, as for example, the diaphragm switch MB as illustrated in Figure 22 which is connected to the storage tank 89 so that when an air pressure exists in said tank above a predetermined, safe pressure the air impinging on the diaphragm of the unit G9 will cause the rod Isl to swing the arm I42 upwardly on its pivot I43 to thereby elevate the connecting rod I44 to thus swing the switch arm I45 upwardly to move the switch let, which is adapted to be interposed in the circuit of the electric motor, not shown, to a circuit interrupting position. The electric motor will thus be de-energized to stop operation of the turbine wheel 34 until the pressure in the tank 35 diminishes sufficiently so that the adjustable weight I 41 will swing the lever I42 downwardly and cause the switch arm I45 to be swung downwardly and back to a circuit closing position of the switch M6 to thereby again energize the electric motor for driving the turbine wheel 34.

The shaft AI may also be driven by other means not capable of being started and stopped by the switch 146,-as for example, a gasoline or diesel engine, not shown, in which case another type of cam may be utilized to prevent the building up of too great an air pressure in the storage tank, as for example the cam means as 9 illustrated in Figures 11 to 14 comprising an annular groove Ml formed in the inner side of the end wall 29a in which are positioned a pair of corresponding oppositely disposed cam tracks, designated generally M8, each including two arcuately curved strips 549 having adjacent ends which are connected by a hinge 55d. Said cam strips Mid have remote ends which slidably engage portions of the bed of the groove i i? and are provided adjacent said remote ends with crossarms ltd which extend into undercut inwardly opening grooves 552 which are formed in the upright side walls of the groove Ml and which open into the sides of said groove. A pin I53 extends upwardly through each arm lei and is reciprocally mounted therein and has a roller let journalled in its upper end, which rollers engage the top walls of the grooves 152 and are yieldably urged upwardly into engagement therewith by springs I55 which are carried by the pins :53 and urge said pins and rollers upwardly. The pin itii oi the hinge I56 has an outer end which extends into another recessed portion I? of the end wall 29a and on which is swingably mounted one end of a lever I53 on the opposite end of which is journalled a shaft W9. A roller I69 is journalled on the outer end of the shaft I55} and engages a groove ifiI formed in the outer wall of the recess 57. A link I62 is likewise connected to the shaft I59 and to one end of a pull spring Hi3 which is anchored to the wall Zea at its opposite end at I64. It will be readily apparent that the spring its will exert a pull on the lever its to cause the roller its to travel toward said spring for swinging the lever I58 toward an upright position to elevate the hinged intermediate portion I50 of the cam track his so that the rollers we will pass over each of the cams Hi8 during each revolution of the turbine wheel St to execute a pumping operation in the same manner as previously described in reference to the form of the invention as illustrated in Figures 1 to 10.

A cylinder 5'65 has an open end which is fastened to the outer side of the wall 29a and contains a piston I65 having a piston rod it? which extends slidably through a stuffing box E58 mounted in the end wall 29a. The opposite end of the piston rod It? is connected to the opposite end of the hinge pin I55. A spring IE9 carried by said piston rod urges the piston rod inwardly of the wall 290. The storage tank tile is provided with a blowoff valve lit which opens into a housing I'll which is connected to the inner portion of the cylinder m5 by a conduit Hi2 and which is additionally provided with a vent port H3. When the air pressure becomes excessive in the tank 86a it will overcome the pressure of the spring Ilila to open the relief valve i'iii allowing the air to escape through the conduit P22 into the cylinder IE5 between the stufiing box I68 and the piston 165. The piston I66 will thus be forced by the compressed air toward the outer end of the cylinder I55 and the piston red It! will exert a pull on the hinge pin I56 against the action of the springs IE3 and ltd to draw the hinged ends of the cam sections Hi9 outwardly of the end wall 29a to position said sections MS with their ends more nearly in the same plane thereby reducing the angle or pitch of the track sections 549 to thus minimize the extent that the pistons t5 will be actuated by said cam to thereby reduce or totally.

eliminate the pumping operation of the pistons 55, It will be understood that each cam I43 is provided with all the structure previously described and that both cams are increased or decreased in pitch simultaneously. A limited amount of air will escape from the housing IIi through its vent aperture H3 and as the pressure in the tank a diminishes, as by utilizing a part of the air therein, the air will escape from the cylinder I35 through the vent lit and the spring its cooperates with the spring I53 to urge the track sections it back toward the maximum pitch position for increasing the length or" the strokes of the two pump pistons t5 and accordingly the amount of air which will be pumped thereby.

Figures 15 and i6 illustrate another form of variable cam and wherein the end wall 292) is made relatively thin and is provided with two diametrically spaced supports i'i l which proiect from its inner side and which support the ends of two cam tracks, each designated generally I75 and each of which is substantially semicircular. Each cam track H5 is formed of two corresponding sections lit the adjacent ends of which are connected by hinges ill, a pin lit of which extends outwardly of the outer edges of the sections W5 and is secured to one end of a lever I79. A connecting rod or lint: use is pivotally connected at N35 to the opposite end or the lever Ill; and has a free end fastened to one end of a, pull spring I82 which is anchored at its opposite end by a pin use to the wall 2st and which urges the lever [is to swing in a clockwise direction, as seen in Figure 16 with its lastznentioned end sliding and iulcruming on the wall 2253b for urging the hinged ends of the sections I16 inwardly and while the opposite, free ends slide on the supports Ilhi for causing the cam track sections lit to assume elevated operative positions, as illustrated in dotted lines in Figure 16.

A cylinder Iliiib containing a piston I661) and a connecting rod Hill) is supported on the outer side of the wall 2% in the same manner as the cylinder Hi5, previously described, and said piston rod extends inwardly through the wall 2% and is pivotally connected to a downwardly oil'- set intermediate portion il'tb of the hinge pin lit. The piston rod It??? carries a spring web that also urges the piston rod and piston inwardly of the wall 2% for urging the cam track sections lit to their dotted line positions of Fig ure 16. Air under pressure is supplied to the cylinder i651: inwardly of the piston Itth by a conduit H22) which is connected to a storage tank, not shown, corresponding to the storage tank 86a. by a blowofi valve unit, not shown, corresponding to the unit as illustrated in Figure 12, so that the pistons with of the two cylinders its?) will move the sections or" the two cam tracks H5 into coplanar full line positions as illustrated in Figure 16 when an excessive air pressure exists in the tank to which the conduits iizib are connected, so that the rollers engaging said cam tracks will not be displaced away from the end wall 2%, in order that the pistons will not reciprocate when the storage tank is fully charged with compressed air.

Figures 17 to 21 illustrate another form of variable cam tracks including an end wall 290 having parallel cam track receiving recesses its the side walls of which are provided with inwardly opening grooves 585 for receiving plates itt, the side edegs of which are slidably mounted in said grooves for movement toward and away from one another and are urged toward one anasses l 1 other by expansion springs I81. A cylinder I650, piston I660 and piston rod IE'I'c form a unit corresponding to the piston, cylinder and piston rod units of Figures 12 and 16 and wherein the piston rod is urged inwardly of the wall 280 by a spring I590, it being understood that one of said units is associated with each groove it. However, the inner end of the piston rod I670 bears against the intermediate portion of a rigid inverted V-shaped cam track I88, the apex of which is normally disposed beneath and between the adjacent ends of the plates I85, when the cams are in inoperative positions, as illustrated in Figure 18. A lever, link and spring unit Ilec, H380 and I820, respectively, similar to the unit of Figures 15 and 16 is connected to a rod or shaft I180 which projects laterally from the upper end of each piston rod Idle and said lever, link and spring units are disposed in separate recesses its of the wall 290 which open into the outer sides of the recesses list and each of which has an outer wall containing a guide groove ItEi for an extension of an end of the pin Iti connecting each lever I190 and link I390, so that said unit can be urged with the piston and piston rod inwardly, in combination with the spring I690 for urging the cam track It?) to a projected, operative position as illustrated in Figure 19. The plates I86 are provided with rollers lei on their inner sides, near their adjacent ends by means of which said plates are spread away from one another against the action of the springs is; when the cam tracks I88 are moved to projected positions as illustrated in Figure 19 by the springs IfiQc and 582e, so that the rollers ltd at each revolution of the turbine wheel 34' will ride over each of the two sets of plates I85 and over the inclined surfaces of each of the cam tracks I38 to cause each or the pistons 95 to complete two strokes at each revolution of the turbine wheel 34. The cam tracks I83 are moved to retracted positions by air entering the cylinders Ifitic" inwardly of the pistons I660 through conduits H20, all in the same manner as previously described and as full illustrated in Figure 12, so that'when a storage tank, not shown, is fully charged with compressed air the cam tracks M8 will be in retracted positions as illustrated in Figure 18'to cause the rollers I3 2 to ride over the plates I85 and the inner surface of the wall 290 without being displaced longitudinally of the turbine casing suficiently to pump air from the cylinders 55 through the cylinder heads 34.

In order to insure that the rollers I04 will be disposed for rolling engagement at all times either with an inclined cam surface or a flat surface, each fork m3 is secured nonrotatably to its piston rod 95 by a setscrew I92 Additionally, the piston rods 96 are provided with flat portions I93 so that the piston rods are of noncircular cross section, as best seen in Figure 9, for slidably and nonrotatably engaging bores I94 in the guide heads 9'! which are of noncircular cross section, as best illustrated in Figure 6. Each fiat surface I93 extends to the outer end of its piston rod 96 so that the piston rods may be inserted through the bores I94 before the forks "33 are secured thereto. By this construction, the oil passages I36 will always be properly positioned to move into registry with the oil passages I34.

Various other modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims;

, 12'- I claim as my invention: 7 1'. A rotary type air compressor comprising a casing having first and second end walls and a cylindrical side wall, a stationary shaft secured to one of said end walls and extending axially into and partially through the casing, a drivenrotary shaft extending axially into the casing through the other second end wall and journalled therein, a rotor journalled on the stationary shaft for rotation within the casing and coupled to said driven shaft and rotated thereby, a turbine unit secured around the periphery of the rotor for rotation therewith within the casing and extending outwardly therefrom to adjacent the cylindrical wall of the casing and including a plurality of circumferentially spaced vanes. forming scoops having leading outer edges disposed in advance of their trailing inner edges, said cylindrical casing wall having air inlet ports adjacent said turbine unit through which air is drawn into the casing from pockets of the turbine unit formed between the vanes thereof by rotation of the rotor, cylinders formed in said rotor and disposed longitudinally thereof between the turbine unit and the stationary shaft, said rotor being provided with air passages leading from the pockets of the turbine unit to said cylinders, said rotor and stationary shaft having communicating passages extending from corresponding ends of said cylinders and opening outwardly of an outer end of the stationary shaft, pistons reciprocally mounted in said cylinders having piston rods extending therefrom away from the last mentioned rotor passages and toward the second casing end wall, spring means carried by said piston rods for urging the piston rods and pistons toward said second end wall, and cam means associated with the second end wall engaging said piston rods for intermittently displacing the piston rods and pistons toward the last mentioned rotor air passages for compressing air in the cylinders and forcing the compressed air through the last mentioned rotor passages into the stationary shaft passage, said turbine forcing air under pressure into said cylinders in certain positions of the pistons relatively to the cylinders whereby the pistons on their compression strokes will initially operate on air partially compressed insaid cylinders.

2. A rotary type compressor as in claim 1, said rotor and turbine unit being cooled by the air drawn into the casing by the turbine unit and expelled inwardly therefrom into said cylinders, said rotor having an annular air chamber surrounding a portion of its periphery communicating with the first mentioned rotor passages and opening into the turbine unit pockets in which the air is compressed and propelled circumferentially of the rotor to the first mentioned rotor passages for cooling the peripheral portion of the rotor.

3. A rotary type air compressor as in claim 1, said first mentioned passages opening into the cylinders remote from said cylinder ends and being closed by the pistons during the initial movements thereof from retracted positions, remote to the cylinder ends, toward said cylinder en s.

4. A rotary type air compressor as in claim 3, each of said first mentioned passages including an annular inner portion formed in the cylinder bore, each of said cylinders including a sleeve in which the piston is reciprocally mounted havinga plurality of circumferentially spaced ports extending radially therethrough and communicating with the annular portion of the first sure into the cylinders between the pistons and i guide members will pass through the pistons toward the cylinder heads during the movement of the pistons toward the guide members for charging the cylinders with compressed air on the I return strokes of the pistons.

6. A rotary type air compressor as in claim 5, and lubricating means for lubricating the rotor, pistons and piston rods including a rotary pump mounted in a stationary position within the casing and driven by the rotor, a lubricant reservoir formed in a portion of the casing and connected to the pump intake, and a conduit leading from the pump outlet having branch passages for lubricating the driven shaft, rotor, pistons and piston rods.

7. A rotary type compressor as in claim 6, said outlet conduit of the pump including a passage extending longitudinally of the stationary shaft and an annular groove formed in a portion of the periphery of the stationary shaft.

8. A rotary type air compressor as in claim 1, the periphery of said rotor being provided with longitudinally spaced annular ribs on which said turbine vanes are mounted and secured, said turbine unit including ring members mounted on the periphery of the rotor against the remote sides of said annular ribs and extending outwardly therefrom to the outer, leading edges of the vanes.

9. A rotary type compressor as in claim 8, said turbine vanes each having a flange at its inner edge extending circumferentially therefrom to adjacent the inner edge of the next trailing vane and combining therewith to form a narrow passage between pockets formed by the adjacent turbine vanes and turbine rings and the annular air 1 chamber formed between the rotor periphery, the vane flanges and said rotor ribs.

10. A rotary type air compressor as in claim 1, said second end wall having at least one arcuately extending recess on its inner face provided with a bed portion inclined from end-to-end thereof forming a cam groove constituting a part of said cam means, and rollers journalled on the ends of the piston rods located remote to the pistons for engaging the cam groove bed on the inner face of i i 4 piston rod rollers when the cam tracks are in projected, operative positions for displacing each of the pistons toward the last mentioned rotor air passages on each revolution of the rotor, and means responsive to an excess pressure of air in a storage container supplied by the air compressor for displacing said cam tracks away from the rotor to an inoperative position whereby the piston rods are not displaced toward the rotor when the storage container is fully charged to render the air compressor inoperative.

12. A rotary type air compressor as in claim 11, each of said cam tracks including a pair of arcuate sections having adjacently disposed hinged ends which are displaceable toward and away from the rotor.

13. A rotary type air compressor as in claim 11, each of said cam tracks including a pair of reciprocally mounted plates disposed for sliding movement toward and away from one another and spring urged toward one another, and an inverted V-shaped track element spring urged toward the rotor between the adjacent ends of said plates and forming the cam portion of the track for displacing the plates away from one another, said cam track portions being displaced away from the rotor to an inoperative position by an excess air pressure in the storage container.

14. A rotary type air compressor comprising a driven rotor, a turbine unit mounted on the periphery thereof including circumferentially spaced vanes having outer leading edges forming scoops adapted to draw air into turbine pockets formed between the adjacent vanes and for propelling the air inwardly toward the axis of the rotor, said rotor having an annular air chamber disposed inwardly of the turbine pockets into which the air is forced from the turbine unit and compressed, said rotor being provided with at least one cylinder disposed between the axis thereof and said annular air chamber having a passage communicating with said air chamber through which air is forced under pressure for charging said cylinder with compressed air, a piston reciprocally mounted in said cylinder and spring urged toward one end thereof, cam means intermittently displacing the piston toward the opposite end of said cylinder, and an air conduit adapted to contain air under pressure including a passage formed in the rotor and communicating with the last mentioned end of said cylinder through which air is forced under pressure when the piston is displaced by said cam means toward the last mentioned cylinder end.

ARTHUR C. EATON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,453,266 Rockwell Nov. 9, 1948 2,540,328 Gray Feb. 6, 1951 2,552,518 Churchman May 15, 1951