US3166236A - Reciprocating piston type gas compressor - Google Patents

Description

Jan. 19, 1965 w. E. MICHENER RECIPROCATING PISTON TYPE GAS COMPRESSOR 3 Sheets-Sheet 1 Original Filed June 23, 1961 INVENTOR.

ATTORNEYS.

Jan. 19, 1965 w. E. MICHENER 3,165,236

RECIPROCATING PISTON TYPE GAS COMPRESSOR Original Filed June 23, 1961 3 Sheets-Sheet 2 INVENTOR. m1 3 M40- ATTORNEYS.

Jan. 19, 1965 w. E. MICHENER 3,156,236

RECIPROCATING PISTON TYPE GAS COMPRESSOR Original Filed June 23, 1961 3 Sheets-Sheet 3 45 ma i?! 0 40 24 v 37 3% E as I 6 INVENTOR. j fi g wicawm/ ATTORNEYS.

United States Patent 3,166,236 RECIPROCATING PISTON TYPE GAS COMPRESSOR William E. Michener, Milwaukee, Wis., assignor to Vilter Manufacturing Corporation, a corporation of Wisconsin Original application June 23, 1961, Ser. No. 119,069, now

Patent No. 3,131,856, dated May 5, 1964. Divided and this application Aug. 9, 1963, Ser. No. 308,052 4 Claims. (Cl. 23030) by the construction of such machines is facilitated and the V efliciency is enhanced.

It has heretofore been common commercial practice to utilize compressors having several stages each embodying a cylinder and a piston cooperating with a set of annular suction and discharge valves, and provided with capacity control mechanism for opening selected suction valves in order to unload the corresponding stages.

These valves are usually formed of relatively thin but durable sheet metal and of large diameter since the suction valve of each stage or compression unit ordinarily surrounds its cylinder adjacent to its outlet end and the discharge valve is located closely adjacent to but beyond this cylinder end so as to reduce the clearance space to a minimum, and each of these valves is constantly urged toward closed position by an annular series of helical compression springs. While this general type and arrangement of annular valves has long been in use, it has been ditlicult to properly guide the same relative to their annular inlet and discharge ports while reducing the clearance spaces to a minimum, and .it was also quite tedious to apply and remove these prior valve assemblages.

Then, too, the capacity control mechanisms of these prior assemblages and which were adapted to lift the suction valves from their seats in order to unload the compressor were also relatively complicated and difiicult to inst-all; and these prior mechanisms were therefore relatively unreliable in operation and required considerable attention in order to maintain them in proper operating condition.

It is therefore an important object of the present invention to provide simple andeffective means for facilitating installation of such valves and of the unloading devices associated therewith so as to insure most efiicient functioning of these compressors with least attention.

Another important object of this invention is to provide far more reliable guiding of the annular plate valves of such gas compressors in order to eliminate excessive clearance space and to maintain both the inlet and dis charge valves properly centralized relative to their seats and ports.

A further important object of the invention is to provide a simplified and improved capacity control device and mechanism for transmitting motion therefrom to the annular suction valve for the purpose of insuring most eifec tive unloading of the compressor.

Still another important object of the present invention is to provide an improved valving and unloading assemblage for gas compressors, whereby various parts of these mechanisms may be readily pre-assembled and the devices may be installed as complete units within the com- Patented Jan. 19, 1965 pressor housings in proper relation to the individual cylinders. i

These and other more specific objects and advantages of the invention will be apparent from the following detailed description.

A clear conception of the features constituting the present improvements and of the construction and operation of a typical multiple cylinder compressor embody ing the invention may be had by referring to the drawings accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

FIG. lis a diagrammatic side view of a multi-cylinder piston type of gas compressor embodying four pairs of radial cylinders each having therein a piston reciprocable from a common crank shaft adapted to be revolved by an electric motor;

FIG. 2 is an enlarged transverse approximately vertical section through the crankcase and through one of the cylinders and valve assemblages of a compressor such as shown in FIG. 1, with one of the capacity control units illustrated in elevation;

FIG. 3 is a further enlarged longitudinal approximately vertical but fragmentary section taken carefully through one pair of adjoining cylinders and through a portion of the corresponding capacity control mechanism, the section being taken along the line 3-3 of FIG. 1;

FIG. 4 is a slightly reduced top view of one of the improved capacity control units showing the same applied to sections through a pair of the compressor cylinders along the line 4-4 of FIG. 3;

FIG. 5 is a transverse section through the capacity control unit or unloading device of FIG. 4, taken along the line 55 of FIG. 6; and

FIG. 6 is 'an approximately vertical section through the same capacity control device, taken along the line 6- -6 of FIG. 4.

While the invention has been illustrated and described herein as having been embodied in a particular type of gas compressor especially adapted for refrigeration service and embodying eight reciprocable motor driven pistons, it is not intended to necessarily confine the use of the improvements to such a compressor; and it is also contemplated that specific descriptive terms employed herein be given the broadest possible interpretation consistent with the disclosure.

Referring to FIGS. 1, 2 and 3 of the drawings, the gas compressor illustrated therein comprises in general; a main frame 9 having therein a suction chamber 10 communicating with a crankcase .10 in which alcrankshaft 11 is revolvable by an electric motor 12; four pairs of cylinders 13 mounted in the frame 9 and radiating from the axis of the crankshaft 11; a piston 14 reciprocable within each of the cylinders 13 by a connecting rod 15 attached to the crankshaft 11; an annular suction valve 16 surrounding the outer end of eachcylinder ,13-and coacting with inlet ports 17 which are communicable with the suction chamber 10 and with the adjacent piston displacement chamber 18; an annular discharge valve 19 coacting with an annular series of outlet ports 20 which communicate with the adjacent chamber 18 of each cylinder 13 through a head 21; a cover 22 enclosing each pair of heads 21 and communicating with a common compressed gas discharge space 23; and a capacity control unit 24 cooperable with selected pairs of cylinders 13 and being operable to lift the suction valves 16 thereof in order to unload the compressor.

The main frame is preferably formed of a sturdy integral casting and when the compressor is motor driven as shown in FIG. 1, the motor 12 and frame 9 may be mounted upon a foundation base 26 as illustrated. Each cylinder 13 is provided with an integral flange 27 at :29 as in FIG. 3, and which has an annular series of small helical compression springs 30 confined therein and coacting with the adjacent plate valve 17. Each cylinder closure end head 21 is secured to another removable an- 'nular guard 31 by a bolt 32 as depicted in FIGS. 2 and 3,

I and each of these guards also confines an annular series of small helical compression springs 33 which coact with the adjacent plate valve 19. Each discharge valve guard 31 and cylinder head 21 is normally held within and in snug engagement with the adjacent normally stationary suction valve guard 28'by means of a large and strong helical spring 34 reacting against the adjacent cover 22; and these covers are detachably secured to the frame 9 by cap screws 35.

It is important (that the periphery of each annular suction valve 16 cooperates with its guard 28 with minimum clearance and that the periphery of each annular discharge valve 19 likewise cooperates with its guard 31, in order that these valves will be constantly centralized with respect to their ports 17, 20, respectively, and the annular series of springs 30, 33 urge the valves 16, 19 toward their seats. It is also noteworthy that although the cylinder closure heads 21 are relatively thin and thus I reduce the compression clearance to a minimum, these heads 21 are amply reinforced against possible distortion by the heavy guards 31 with which the heavy springs 34 coact; and the cap screws 29, 35 enable the entire suction and discharge valve assemblages to be assembled externally of the frame 9 and applied as individual units to the compressor in assembled condition or removed in like condition for inspection and possible renewal of worn or broken valves 16, 19.

The improved capacity control units 24 which coact with selected suction valves 16 for the. purpose of unloading the compressor are mounted upon a partition 37 which spans the crankcase 10' but is subjected to suction pressure on both sides, as shown in FIG. 2, but each of the units 24 cooperates with both suction valves 16 of the selected pair of cylinders 13 in the manner illustrated in FIGS. 3 to 6 inclusive. Each unloading unit comprises in general a guide member 38 having thereon a central bore 39 and four upright guide pins 40 disposed parallel to this bore while two parallel upright pivot pins 41 are secured to the member 38 between the guide pins 40; a plunger 42 reciprocable within the bore'39 and having a rod 43 rising upwardly between the pivot pins 41; a horizontal H-shaped yoke 44 penetrated by and "slidable along the pivot pins 41 and being constantly urged in an upward direction by relatively heavy springs 45 surrounding the shorter guide pins 40 and coacting with the member 38 and the yoke 44; a pair of levers 46 pivotally attached 'to the upper ends of the pins 41 by pivots 47 and coacting at their opposite ends with the plunger rod 43 and yoke 44 respectively; and means for transmitting motion of the yoke 44 to the adjacent suction valves 16 of the selected pair of compression cylinders and pistons.

Gas under pressure derived from the discharge chamber of the compressor or from any other source of control is admissible to the displacement chambers of the unloading unit plungers 42 through conduits 49, and a relatively light helical spring 50 coacts with the lower face of each plunger in order to eliminate lost motion in the linkage. The laterally projecting four prongs or arms of the H-shaped yoke 44 extend to diametrically opposed sides of the adjacent pair of cylinders 13 as shown in FIG. 4, and the free ends of these arms are adapted to coact with rings 51 which surround and are slidable along the adjacent cylinder walls and carry annular sets of parallel rods 52 reciprocable through parallel holes in the adjacent cylinder flanges 27 and which are engageable with the corresponding suction valves 16 to lift them from their seats and hold them open during unloading operations. A helical spring 53 surrounds each rod 52 between the adjacent cylinder flange 27 and the ring 51, and each ring is recessed internally to provide a stop 54 cooperable with a snap ring 55, in order to limit the downward movement of the adjacent ring 51 as clearly shown in FIG. 3.

With the various parts of the compressor constructed as hereinabove described, the several cylinders 13 with the rings 51 and snap rings 55 applied thereto may be pressed within the radially alined sets of openings in the frame 9 and properly positioned by means of stop rings 57 as shown in FIGS. 2 and 3, and the pistons 14, connecting rods 15, crankshaft 11 and other accessories normally confined within the crankcase 10' may be readily installed in an obvious manner upon removal of the cover plate 58. The capacity control units 24 may also be readily installed through the radial outer frame openings and applied to the cylinders 13 with which they are to cooperate, before these cylinders are installed in the frame 9.

But the suction and discharge valve assemblages including the valves 16, 19, the cylinder heads 21, the guides 28, 31, the light springs 30, 33, and the heavy springs 34 may be assembled on a workbench and applied as complete units to their respective cylinders 13 and secured in place with the aid of the cap screws 29, and the covers 22 .and cap screws 35 to finish the compressor installation. These valve assemblages may also be just as readily removed for inspection and possible replacement of worn or broken valves16, 19, with minimum elfort and loss of time, and when assembled the valves 16, 19 will always be maintained properly centralized with respect to their annular ports 17, 20 by the guides 28, 31.

During normal operation of the improved compressor, the motor 12 revolves the crankshaft 11 causing it to reciprocate the several sets of pistons 14 in succession during each revolution of the cranks. During each inward travel of the pistons 14, gas will be drawn from within the suction chamber 10 through the ports 17 and past the suction valves 16 into the corresponding displacement chambers 18; and when the compressor is operating at full capacity, outward travel of each piston 14 will compress and deliver the gas admitted to its displacement chamber 18 through the ports 20 and past the discharge valves 19 into the discharge conduit 23. However, if the compressor is to be partially unloaded, the capacity control units 24 will function to automatically hold the corresponding suction valves 16 from their seats'during the discharge stroke of the adjacent pistons 14 thus preventing delivery of compressed gas from the cylinders 13 with which the units 24 cooperate.

From the foregoing description of the construction and operation of the devices, it should be apparent that the present invention in fact provides an improved reciprocating piston type of gas compressor which is simple and efiicient and wherein the various parts may be readily assembled and installed or removed when necessary. The valves 16, 19 are effectively guided to prevent lateral shifting, and each cylinder has minimum clearance space thereby enhancing the efficiency of the unit, and the ports 17, 20 are usually formed as similar series of openings in a well-known manner. The improved capacity control units 24 are also compact and durable in structure and can be conveniently installed, and the entire assemblage has proven highly satisfactory and successful in commercial use especially as applied to refrigeration systems.

I claim:

1. A gas compressor comprising, a main frame, a

cylinder mounted in said frame and having a bore and an integral external flange near an end of the bore provided with a series of suction ports and with a series of through holes, said cylinder also having an annular external groove remote from said flange, a piston reciprocable within said bore toward and away from said flanged cylinder end, an annular guide detachably secured to said flange, an annular suction valve coacting with said guide and with said suction ports, a ring slidable along the cylinder exterior and being provided with rods movable through said holes to lift the suction valve, an annular stop seated within the external groove of said cylinder to provide a seat for limiting movement of said ring, a closure plate for said bore end loosely coacting with said suction valve guide and having therein a series of discharge ports, a second annular guide secured to said plate and also loosely coacting with said suction valve guide, an annular discharge valve coacting with said second guide and with said discharge ports, a cover cooperable with said frame to provide a compressed gas chamber, and resilient means interposed between said cover and said second guide to detachably maintain said guides and said closure plate in position, said guides coacting with said valves to prevent lateral displacement of the latter relative to their axes of annularity.

2. A gas compressor comprising, a main frame, a cylinder mounted in said frame and having a bore and an integral external flange near an end of the bore provided with a series of parallel through holes and suction ports, a piston reciprocable within said bore toward and away from said flanged cylinder end, an annular guide detachably secured to said flange, an annular suction valve coacting with said guide and with said suction ports, a ring slidable along the cylinder exterior and having thereon a series of parallel rods movable through said holes to lift the suction valve, a closure plate for said bore end coacting with said suction valve guide and having therein a series of discharge ports, a second annular guide secured to said plate and also coacting with said suction valve guide, an annular discharge valve coacting with said second guide and with said discharge ports, a cover co operable with said frame to provide a compressed gas chamber, spring means interposed between said cover and said second guide to detachably maintain said guides and said closure plate in position, and a capacity control unit cooperable with said ring to unload the compressor, said capacity control unit including a yoke coacting with said ring and having guide means and an actuator for moving said yoke in a rectilinear path to thereby move said ring.

6 3. A gas compressor comprising, a main frame, a cylinder mounted in said frame and having an end flange provided with suction ports and with a series of parallel holes and also having an annular external stop remote from the end flange, a piston reciprocable within said cylinder toward and away from said end, an annular suction valve vcooperable with said ports, a ring slidable along said cylinder and having a series of parallel rods movable through said holes to lift said valve away from said ports to unload the compressor, said ring being engageable with said stop, and being guided thereby throughout its range of movement, springs coacting with said ring to urge said rods away from said valve, a yoke cooperable with said ring to move said rods toward said valve, parallel stationary guide rods for said yoke, a fluid pressure actuated plunger, and levers pivotally attached to said guide rods and being swingable by said plunger to eflect movement of said ring in opposition to said springs.

4. A gas compressor comprising, a main frame, a cylinder mounted in said frame and having an end flange provided with suction ports and with a series of parallel holes, a piston reciprocable Within said cylinder toward and away from said end, an annular suction valve coopcrable with said ports, a ring slidable along said cylinder and having a series of parallel rods movable through said holes to lift said valve away from said ports to unload the compressor, springs surrounding said rods and coacting with said flange to urge the rods away from said valve, a yoke cooperable with said ring to move said rods toward said valve, parallel stationary guide rods for said yoke, a fluid pressure actuated plunger disposed between said guide rods, and levers pivotally attached to said guide rods and being swingable about their pivots by said plunger to move said yoke and thereby eflect movement of said ring in opposition to said springs.

References Cited by the Examiner UNITED STATES PATENTS 2,185,473 1/40 Neeson 2303l 2,836,345 5/58 Gerteis 23031 3,071,309 1/63 Hackbart 230-- FOREIGN PATENTS 160,230 12/54 Australia.

LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner.

Claims (1)

1. A GAS COMPRESSOR COMPRISING, A MAIN FRAME, A CYLINDER MOUNTED IN SAID FRAME AND HAVING A BORE AND AN INTEGRAL EXTERNAL FLANGE NEAR AN END OF THE BORE PROVIDED WITH A SERIES OF SUCTION PORTS AND WITH A SERIES OF THROUGH HOLES, SAID CYLINDER ALSO HAVING AN ANNULAR EXTERNAL GROOVE REMOTE FROM SAID FLANGE, A PISTON RECIPROCABLE WITHIN SAID BORE TOWARD AND AWAY FROM SAID FLANGED CYLINDER END, AN ANNULAR GUIDE DETACHABLY SECURED TO SAID FLANGE, AN ANNULAR SUCTION VALVE COACTING WITH SAID GUIDE AND WITH SAID SUCTON PORTS, A RING SLIDABLE ALONG THE CYLINDER EXTERIOR AND BEING PROVIDED WITH RODS MOVABLE THROUGH SAID HOLES TO LIFT THE SUCTION VALVE, AN ANNULAR STOP SEATED WITHIN THE EXTERNAL GROOVE AND SAID CYLINDER TO PROVIDE A SEAT FOR LIMITING MOVEMENT OF SAID RING, A CLOSURE PLATE FOR SAID BORE END LOOSELY COACTING WITH SAID SUCTION VALVE GUIDE AND HAVING THEREIN A SERIES OF DISCHARGE PORTS, A SECOND ANNULAR GUIDE SECURED TO SAID PLATE AND ALSO LOOSELY COACTING WITH SAID SUCTION VALVE GUIDE, AN ANNULAR DISCHARGE VALVE COACTING WITH SAID SECOND GUIDE AND WITH SAID DISCHARGE PORTS, A COVER COOPERABLE WITH SAID FRAME TO PROVIDE A COMPRESSED GAS CHAMBER, AND RESILIENT MEANS INTERPOSED BETWEEN SAID COVER AND SAID SECOND GUIDE TO DETACHABLY MAINTAIN SAID GUIDES AND SAID CLOSURE PLATE IN POSITION, SAID GUIDES COACTING WITH SAID VALVES TO PREVENT DISPLACEMENT OF THE LATTER RELATIVE TO THEIR AXES OF ANNULARITY.

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