US2545791A - Fluid compressor - Google Patents

Description

March 20, 1951 w. w. PAGET FLUID COMPRESSOR Filed Oct. 15, 1944 2 Sheets-Sheet 1 1220622202 Mia zipajei. 3 ,zm-l mw March 20, 1951 w. w. PAGET FLUID COMPRESSOR 2 Sheets-Sheet 2 Filed Oct. 15, 1944 4 7f 60 174 111 H 6/ .53 Jo 64y h 5 i 4.? MM a 77 v v 4y Patented Mar. 20, 1951 FLUID COMPRESSOR Win W. Paget, chigan City, Ind-, assi nor to Joy Manufacturing Company, acorporati'on of Pennsylvania Application October s, 1944, :Serial no. 558,554

15 Claims. 1

'My invention relates to fluid compressors .or pumps, :and vmore particularly to compressors for air or other gaseous rfluid.

It is desirable that the temperature of a fluid discharged from a compressor be maintained low, and this may ,be assisted by a reduction in the heating of the .fluid flowing to the compressor through the intake passages. Since the .in. take and discharge passages :of a compressor are usually in close proximity to each other, there should be provided some .means for reducing the transfer of heat .from .thecompressed fluid to the fluid in the intake. It is .also desirable that the compressor be provided with .an unloading .device whichoperates ata predetermineddischarge pressure to cutoff the :supply .of fluid to ,a receiver or to some point of use, and this unload- .ing device should =operategso as to prevent as much as possible the heating of .the compresor during continued operation of the latter after .unloading takes place. It .is also desirable to .start the compressor under no load.

In .a preferred form of .my invention there .is shown .a compressor having .intake passages which are lined with an insulating material to reduce the transfer of heat to the fluid therein. Insulation is also provided to reduce the transter of heat to the intake connections leading to the compressor cylinders. The discharge passages are formedina material which is .a good heat conductor, and these passages are .so arranged that large cooling surfacesare obtained. "-I he unloading device .is designed to vcut off the -flow of fluid Lto.-.the intake and to ventthe discharge passages which may be associated with .ac0oling device such as an aftereooler so that .any rluid leaking to the intake passages will not be :compressed and discharged against a high ."pressure in the discharge line. The-venting of :the discharge line also assures against the ,de-

(C1. 23.0-r24) V Eliveryof any fluid toa receiver or to :a point .of

pylinder intake to be attended by ,relief of the 5 load on the-discharge-sideof-thecylinder. In a preferred embodiment :an intake closure valve, a -,discharge -line vent. valve and a :common element movable upon I predetermined discharge pressure variations automatically to fiefiiect -.i-ntake closure valve closing and discharge line vent valve .opening, may ,be provided. Qesirably the two valve means may/in such preferred embodiment, be coaxiall y arranged and the common operating element ,may be a fluid operated piston asso- .ciated with one of said valvemeans, and preferably the intake closure valve means.

vtin object .of my invention is to provide an improved pump-or compressor. Another object of my invention is to provide a compressor having improved means for preventing the heating of the fluid therein. .Still another object is to provide a compressor having improved means for preventing the transfer of heat etween the in.- take and d charge pas ages. Yet another ob- .J'ect is to sprovidela compressor having improved lo in mean ,An ther object is t prov for a compressor an improved unloading means which .is operative to control the flow of fluid relative .to the intake and discharge passages. .still another object is to provide an improved unloading means which isoperative at a predetermined compressor .discharge pressure for cutt n th flow o fluid t the comp esso o intake and venting the ..compressor discharge. Another object ;is to provide an improved ,unlo ng m ans havin valve means for control- ;ling-therflowof ,fluid relative to the intake end of a compressor and having other valve means for controlling the venting of the compressor discharge, and .means responsive to compressor,- -discharge pressure for actuating each of said valve means. .A still f urtherobjectis to provide improved means associated with .an intake closure unloader yfor venting the aftercooler of a compressor. Qt-her objects will appear in the :course of the followingdescription.

I-n the accompanyin drawings there is shown :for purp se o ll strat onpne f rm wh h my invention may assu incur-act ve .In :these drawings:

fig. :1 is .a side .elevational "view of a compressor having :myimproved unloading .means and insulating means eembodied therein.

Fig. 2 is an enlarged cross-sectional-view, .with certain parts shown :in elevation and other parts omitted to facilitate"illustration, taken substan- :tialiy on the jline;2.;2 of Fig. -1.

;F ig. ,3115 anerilargedsectionalview taken on .theplanespf ,the line ;3fi o f j F. ig. l, and showing theintakeand. discharge manifolds and the unloading -means associated therewith.

Fig. A is ,a cross-sectional .view taken on the plane of theglinea fid qf.Eis. BL ithpaIt infal Fig. 5 is a view taken on the plane of the line 5-5 of Fig. 2 with parts omitted.

Fig. 6 is an enlarged sectional view of the automatic vent valve.

In the illustrative embodiment of my invention there is shown a pump mechanism or compressor, generally designated l, driven by a power unit 2 and delivering fluid to a receiver 3.

The compressor, as shown herein, is of the V-type and includes a crankcase 5 supported by a frame 6 and having two guide cylinders 8 and 9 connected thereto, as by bolts ID, in angularly spaced relation. Connected to flanges II at the outer ends of the guide cylinders, as by bolts I2, are compressor cylinders l4'and I5, and attached, as by bolts 16, to the outer ends of the compressor cylinders are cylinder heads l1. .and IS. The guide cylinders, the compressor cylinders, and the cylinder heads are identical in each pair, so the detailed structure of only one of each need be shown and described.

Each of the guide cylinders has a guideway 29 for reciprocably guiding a crosshead 2| which is connected by a connecting rod 22 to a crankshaft 23 driven by the power unit 2. The crosshead is also connected to a piston rod 25 which is attached to a piston 26 reciprocably mounted in a bore 21 in the compressor cylinder. Clamped between the guide cylinder and the compressor cylinder is a plate 29 having an opening 39 through which the piston rod extends, and arranged within the opening 30 is a packing ring 3| sealingly engaging the piston rod. At the lower end of the compressor cylinder is a port 32 connecting the space in the cylinder beneath the piston in free communication with the atmosphere. Each of the cylinder heads is provided with an intake passage 33 and a discharge passage 34, the intake and discharge passages communicating respectively with the cylinder bore under the control of inlet and discharge valves 35 and 36. The intake passage 33 is provided with a liner 3! made of an insulating material such as Synthane and operating to reduce the transfer of heat from the compressed fluid through the cylinder head walls to the fluid in the intake passage. A cap 38 is connected, as by bolts 39, at the top of each cylinder head and provides an intake chamber 40 into which one of the intake passages 33 opens. Arranged between the cap 38 and the adjacent head portion is a plate 4| made of an insulating material such as that mentioned above so as to reduce the transfer of heat from the adjacent head portion to the cap. Attached to the ca 38, as by bolts 42, is an intake manifold 43 having a passage 44 which communicates freely with each of the chambers 40. Attached to the sides of the cylinder heads, as by bolts '45, is a combined discharge manifold and aftercooler 46 having a passage 4? communicating freely with each of the discharge passages 34. Formed on the guide cylinders, the compressor cylinders, the cylinder heads, and the discharge manifold are cooling fins 49, 50, 5| and 52, respectively. I

The intake and discharge manifolds have at their mid-portions enlargements 53 and 54 which cooperate to provide a housing for unloading means generally designated 55. Formed in the enlargement 53 is a chamber 56 into which a fluid supply conduit 5'! opens, and this chamber communicates past a valve-seat-providing member 58 with the passage 44 in the intake manifold. A cover plate 59 attached, as by bolts 60, to the top of the enlargement 53 closes the chama manifold through a port 83.

ber 55 and provides a. depending annular portion BI on which a hollow intake closure valve 62 is reciprocably guided. The valve member 62 has an enlarged portion 63 carrying a packing ring 54 which sliclably engages the outer walls of the depending portion 6 I, and also has a reduced portion 65 extending through the member 58 and through an opening 56 in the opposite wall of the intake manifold. A packing ring 68 carried by the intake manifold engages the reduced portion 65 and prevents the escape of fluid from the passage 44 through the opening 65. Between the portions 63 and 65 of the valve member is a portion 10 engageable with the member 58 for cutting off the flow of fluid between the chamber 55 and the passage 44. Surrounding the reduced portion 65 is a spring H acting between a wall of the intake manifold and a shoulder 12 on the valve member for urging the latter toward its unseated position. The interior of the valve member cooperates with the annular portion 5! to form a chamber 14 into which a conduit 15 opens through the cover plate 59. Any suitable pilot valve mechanism, not shown, may be used to connect the conduit 15 alternatively with the receiver or with atmosphere, depending upon whether receiver pressure is at its desired upper limit or so lowered as to make renewed pumping desirable. When the receiver pressure reaches a predetermined maximum value, the valve member 62 is forced downwardly against the action of the spring H until it engages the member 58 and cuts off the flow of fluid from the chamber 56 to the passage 44.

The enlargements 55 and 54 have therebetween a space 18 into which the reduced portion 55 of the valve member 52 projects when the latter is moved to its lower position. Arranged between the enlargement 54 and the lower side of the intake manifold are shims 19 which are adjusted to limit the distance at which the portion 65 may extend into the space 18. Between the shims l9 and the intake manifold is a layer of insulating material 89 to reduce the transfer of heat from the discharge manifold to the intake manifold. The sides of the space 18 communicate, as shown in Fig. 4, freely with the atmosphere. At the bottom of the space 18 is an enlarged wall portion 8| in the discharge manifold, and this wall portion is provided with a recess 82 opening into the passage 4'! in the discharge Threaded into the recess 82 is a valve seat member 84 having a port 85 connecting the recess 82 and space 18 in communication with each other. Received within the recess 82 is a valve member 86 engageable with the valve seat member 54 for cutting off the flow of fluid through the port 85, and a spring 88 acts between the bottom of the recess 82 and the valve member 86 for urging the latter into engagement with the member 94. The valve member 88 has a reduced portion 89 extending through the port 85 with sufficient clearance to permit fluid to flow freely through the latter when the member 36 is moved out of engagement with the member 84, and the portion 89 extends to a point where it is engageable by the portion 65 of the valve member 52 and is forced to its open position when the latter is moved to its closed position. The larger portion of the valve body has radial ports through which fluid may flow from the port 83 and through the hollow interior of the valve body to the clearance space about the portion 89 (Fig. 6). The enlargement 54 provides at the lower side of the discharge manifold a chamber 9! communicating with a discharge conduit 92 leading to the receiver 3, and the pasage 41 in the discharge manifold communicates through a port 93 withthe chamber 9| under the control of a valve 94. The valve 94 has a valve stem 95 which is slidably received within a bushing 96 carried by a plate 9! closing the chamber 9|, and a spring 98 acts between the plate 91 and the valve stem 95 for urging the valve 94 toward a position cutting off the flow of fluid through the port 93.

During operation of the compressor when the receiver pressure is low, the valve member 62 is held in its open position by the spring H, and the valve member 86 is held in its closed position by the spring 88. Fluid then flows from the conduit 51 through the chamber 55 and past the,

valve seat member 58 to the intake passage 44 where it is delivered to the chambers 40 at the outer ends of the cylinder heads I! and [8. The fluid passes from the chambers iii to the intake passages 33 and is conducted past the inlet valves 35 to the cylinder bores 2'? where it is compressed and then discharged past the discharge valves 38 to the passages 34 in the cylinder heads. The compressed fluid flows from the passages 34 to the discharge pasage 41 in the combined. discharge manifold and aftercooler.

The valve 34 is opened by the pressure of the fluid in the passage 4'! and fluid then flows past the valve 94 to the chamber 9: where it enters the discharge conduit 92 and is conducted to the receiver 3. When the receiver pressure reaches a value suflicient to cause fluid to be supplied to move the valve member 62 against the action of the spring 1!, the fluid caused to be delivered from the receiver through the conduit '55 to the interior of the valve member 62 results in the latter moving to its closed position cutting off the supply of fluid to the passage 44 in the intake manifold. As the valve member 62 closes, it en gages the stem 89 on the valve member 86 and forces the latter to its open position for venting fluid from the passage 4'! in the combined discharge manifold and aftercooler. The valve member 94 then closes against the action of the reduced fluid pressure and prevents the escape of fluid from the receiver. When the pressure in the receiver drops below a predetermined value the conduit is caused to be vented, thereby venting the fluid acting on the valve member 62 resulting in the latter moving to its open position again. to admit fluid to the intake passage. When the stem of the valve member 62 moves away from the vent valve 86, the latter is moved by its spring to its closed position, cutting off the vent for the discharge passage. As the pressure builds up in the discharge manifold, the valve 94 is automatically opened to permit flow of compressed fluid to the receiver. As mentioned above a pilot valve mechanism of conventional form is employed to connect the conduit 15 alternatively with the receiver or with the atmosphere, depending upon whether receiver pressure is at its desired upper limit or has fallen a predetermined amount below such upper limit.

It will be understood that the compressor mechanism shown isv merely illustrative of an arrangement with which my improved unloading means is adapted for use, and that this unloading means may be used as well with a compressor having one or more than two cylinders.

As a result of my invention there is provided an improved unloading means which is adapted pressor by controlling simultaneously the flow of fluid in the intake and discharge passages. By venting the discharge passages to atmosphere during unloading there is prevented any supply to the receiver of fluid which may leak past the intake closure valve to the compressor cylinder where it would be compressed and discharged to the discharge manifold. By venting the discharge manifold, starting of the compressor while loaded is prevented. There is also prevented a discharge of such fluid against any substantial pressure in the discharge line and resulting in a heating of the compressor during its unloaded operation. By reason of the insulating of the intake passages,

the fluid delivered to the cylinders is cooler and the discharged fluid is correspondingly cooler.

While there is in this application specifically described one form whichthe invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration, and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In combination, a compressor having at least one inlet valve and an intake connection and at least one discharge valve and a discharge connection, an intake closure type unloader valve for shutting ofi flow through said intake connection, a check valve disposed to permit flow from said compressor through said discharge connection and to prevent flow past said check valve towards said compressor through said discharge connection, a vent valve for venting the space between said compressor and said check valve by connecting said discharge connection to atmosphere, and means for effecting closing of said intake closure type unloader valve and opening of said vent valve to effect unloading of said compressor and to prevent, during unloaded operation, the development of excessive temperatures in the compressor due to the raising of the pressure of any fluid which may leak past said intake closure type unloader valve through an excessive number of compressions, said means for effecting closing of said intake closure type unloader valve and opening of said vent valve including means for transmitting movement from said unloader valve, as it moves towards closed position, to said vent valve, to efiect opening of the latter.

2. In combination, a compressor having at least one inlet valve and an intake connection and at least one discharge valve and a discharge connection, an intake closure type unloader valve for shutting ofl flow through said intake connection, a check valve disposed to permit flow from said compressor through said discharge connection and to prevent flow past said check valve towards said compressor through said discharge connection, a vent valve for venting the space between said compressor and said check valve by connecting said discharge connection to atmosphere, and means for effecting closing of said intake closure type unloader valve and opening of said vent valve to effect unloading of said compressor and to prevent, during unloaded operation, the development of excessive temperatures in the compressor due to the raising of the pressure of any fluid which may leak past said It intake closure type unloader valve through an excessive number of compressions, said means for effecting closing of said intake closure type unloader valve and opening of said vent valve including abutments in fixed relation respectively to said intake closure type unloader valve and to said vent valve and engaging each other to preclude simultaneous occupation by said intake closure type unloader valve and said vent valve of their respective closed positions.

3. In combination, a compressor having at least one inlet valve and an intake connection and at least one discharge valve and a discharge connection, an intake closure type unloader valve for shutting off flow through said intake connection, a check valve disposed to permit flow from said compressor through said discharge connection and to prevent flow past said check valve towards said compressor through said discharge connection, a vent valve coaxial with said intake closure type unloader valve for venting the space between said compressor and said check valve by connecting said discharge connection to atmosphere, and means for effecting closing of said intake closure type unloader valve and, through movement imparted to it by said intake closure type unloader valve, opening of said vent valve to effect unloading of said compressor and to prevent, during unloaded operation, the development of excessive temperatures in the compressor due to the raising of the pressure of any fluid which may leak past said intake closure type unloader valve through an excessive number of compressions.

4. In combination, in a fluid compressor, cylinder structures arranged in v-relation, a fluid intake manifold extending between, said cylinder structures for supplying fluid to them and having an intake connection spaced from each of its own ends, a fluid discharge manifold extending between said cylinder structures for receiving fluid from them and having a discharge connection spaced from each of its own ends, an intake closure type unloader valve associated with said intake connection, and a vent valve associated with said discharge connection, said'valves so constructed and arranged that motion is transmited to said vent valve to open the-same when said intake closure valve is moved to closed position.

5. The combination set forth in claim 4 in which said valves each have a stem and said stems are so relatively constructed and arranged that the stem of said unloader valve contacts the stem of said vent valve and actuates it to open said vent valve as said unloader valve is closed.

6. The combination set forth in claim 4 in which said unloader valve and saidvent valve are coaxially disposed and oppositely seating and stem means is associated with each of said valves in such mutual relation that the vent valve is unseated by seating movement of said unloader valve.

'7. In combination, a compressor having an inpositioned that said second element when so moved effects actuation of said first element, with resultant substantially concurrent intake closure and terminal connection venting.

8. In combination, a compressor having an intake and a terminal connection for the discharge of compressed fluid, and unloading means for said compressor including a valve member movable to cut off the admission of fluid to said intake, a valve member movable to a position for venting said terminal connection, an element for moving said last mentioned valve member to effect venting of said terminal connection, means for moving said first mentioned valve member to closed position, and an element moved with said first mentioned valve member as the latter is closed and contacting said first mentioned element to move the latter whereby said second mentioned valve member is moved to open position on closure of said first mentioned valve member.

9. In a mechanism of the character described, in combination, a compressor, intake and discharge passages for said compressor, and unloading means for said compressor including a valve member movable to a position for cutting ofi the supply of fluid to said intake passage, a valve member movable to a position for venting said discharge passage, one of said valve members engageable by the other of said valve members and movable by the latter to its position aforesaid, and means responsive to compressor discharge pressures for effecting movement of said other of said valve members to its position aforesaid.

10. In a mechanism of the character described, in combination, a compressor having a plurality of compressor cylinders, intake and discharge manifolds common to said compressor cylinders, and means for unloading said compressor including a valve member movable to a position for cutting off the flow of fluid to said intake manifold, a valve member movable to a position for venting said discharge manifold, said last mentioned valve member engageable by said first mentioned valve member and movable by the latter to its venting position, and means responsive to compressor discharge pressure and actuated thereby for effecting movement of said first mentioned valve member.

11. In a mechanism of the character described, in combination, a compressor having a plurality of compressor cylinders, means for driving said compressor, intake and discharge manifolds common to said compressor cylinders, and means for unloading said compressor including a valve member movable to a position for cutting off the flow of fluid to said intake manifold, a valve member movable to a position for venting said discharge manifold, said first mentioned valve member responsive to compressor discharge pres- (sures and movable at a predetermined maximum take and a terminal connection for the discharge 7 of compressed fluid, and unloading means for said compressor including a valve member movable to cut off admission of fluid to said intake, a valve member movable to a position for venting said terminal connection, an element for moving one of said valve members as aforesaid, an element moved with the other of said valve members as it is moved as aforesaid, and means for moving as aforesaid said valve member having said second mentioned element movabletherewith. said elements so mutually arranged and pressure to its closed position, and said second mentioned valve member engageable by said first mentioned valve member on movement of the latter to its closed position and movable thereby to its venting position.

I 12. In a compressor, intake and discharge passage means for the compressor, a receiver with which said discharge passage means communicates, an intake closure unloading device for the compressor operative to cut off the supply of fluid to said intake passage means when a predetermined compressor discharge pressure is attained, valve means past which the fluid in said discharge passage means flows to said receiver, and valve means for venting said discharge passage means when the compressor is unloaded, said first mentioned valve means automatically closing to cut oil communication of said receiver with said discharge passage means when the latter is vented.

13. In an apparatus for interrupting the pumping by a compressor and for relieving the load on the compressor upon starting thereof, in combination, a valve'device positionable to effect supply to or interrupt the supply to a pump cylinder, a valve device positionable to relieve the load on the discharge side of the pump or to permit the building up of the load, means for moving said first mentioned valve to interrupt the supply of fluid to be pumped to the cylinder, and means fo efiecting the movement of said second mentioned valve automatically to effect the removal of the load from the pump cylinder when said first mentioned valve assumes its last mentioned position.

14. In a fluid compressor, a pair of spaced compressor cylinders of equal size and capacity and each containing a piston, intake and discharge passage means common to said cylinders and extending therebetween, an intake closure unloading device associated with said intake passage means midway between said cylinders for cutting off fluid supply concurrently to both cylinders when a predetermined compressor discharge pressure is attained, and a venting device as-' sociated with said discharge passage means likewise midway between said cylinders for automatically concurrently venting the discharges from both cylinders when said intake fluid supply is cut oil.

15. In a fluid compressor, a pair of spaced com- 10 pressor cylinders of equal size and capacity and eachcontaining a piston, intake and discharge passage means common to said cylinders and extending therebetween, a reciever with which said discharge passage means communicates, means associated with said intake passage means midway between said cylinders for cutting off fluid supply concurrently to both cylinders when a predetermined pressure is attained in said receiver, means associated with said discharge passage means likewise midway between said cylinders for automatically concurrently venting the discharges from both cylinders when said fluid supply is cut oil, and a valve device for automatically preventing flow of fluid from said receiver to the discharges of both cylinders when said discharge passage means is vented.

WIN W. PAGET.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,644,077 Blom Oct. 4, 1927 1,909,972 Le Valley May 23, 1933 2,041,717 Lamberton May 26, 1936 2,047,489 Pfeifer July 14, 1936 2,137,752 Ferguson Nov. 22, 1938 2,186,492 Paget Jan. 9, 1940 7 2,221,789 Ferguson Nov. 19, 1940 2,302,847 Ferguson Nov. 24, 1942 2,312,335 Halleck Mar. 2, 1943 2,334,209 Lamberton Nov. 16, 1943

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