US2223044A - Compressor governor - Google Patents

Description

Nov. 26, 1940. R. E. MILLER COMPRESSOR GOVERNOR Filed March 51, 1959 //W/////////M//////////////%///T A wl /A l lNvENToR RAYMOND E. MILLER c Mullin-mlm:

TW mul BY/VM ATTORNEY Patented Nov. 26, 1940 Y l UNITED STATES PATENT orifice COMPRESSOR GOVERNOR Raymond E. Miller, Wilkinsburg, Pa., assigner to lThe Westinghouse Air Brake Company, vWilmerding, Pa., a corporation of Pennsylvania i y Application March`31, 1939, Serial No. 265,206

3 Claims. (Cl. 137-153) This invention relates to compressor governor wear, and the usual advantages of a dual comdevices, and more particularly to a compressor pressor equipment are largely lost. governor of the class adapted to be carried on The principal object of my invention is to a locomotive for controlling the supply of steam provide a steam compressor governor device into one or more air compressors in accordance cluding low pressure and high pressure control 5 with the demand for compressed air being supvalves adapted to control both supply andreplied to an air brake system. lease of fluid under pressure to and from a steam A well known type .of compressor governor cut-off valve piston, each of the valves being commonly employed in steam railwayservice adapted for quick operation at one time from v comprises a fluid pressure operated steam valve seated position to fully. open position and for 10 mechanism for controlling the supply of steam an equally rapid closing movement in releasing to the usual compressors, a diaphragm operated uidfrom the piston at another time, so as'to low pressure valve adapted to control supply of avoid possible balancing of the piston in an inuid under pressure to the steam valve mechatermediate position and consequent throttling lnism while the demand for compressed air for of the steam supply. 15 use in the air brake system is low, and a simi- Another object of the invention is to provide lar diaphragm actuated high pressure valve an improved steam compressor governor inadapted to control the supply of iluid under prescluding a steam valve actuating piston,-a plusure to the steam valve mechanism when the rality of pressure controlled valves, each of demand for compressed air is at a maximum. which is responsive to a predetermined pressure 20,

It will be understood that the first mentioned of air in the receiving reservoir for rapidly supor low pressure valve is'adapted to effect conplying fluid under pressure to thepiston, and trol of operation of the compressors in accordmeans for automatically facilitating operation ance with the pressure of air delivered thereby of the active valve while preventing interference to the main reservoirs while the air brakes are therewith by the inactive valve. 25v

in running or release condition, While the high These objects, as well as others, are attained pressure valve is adapted' to perform the same by means of the apparatus hereinafter described function only after an application of the brakes in connection with the accompanying drawing, has been effected, during which time it is dein which the single gure is a vertical sectional sirable to maintain high air pressure in the Vmain View of a steam governor device constructed 30 reservoir. in accordance with the invention.

in order to insure an adequate supply of com- As shown in the drawing, the casing strucpressed air, a locomotive may be equipped with ture of the compressor governor includes a steam two steam driven compressors, both of which valve body i, a cylinder section 2, a casing secare adapted to be simultaneously controlled by tion 3, a valve section 4, and a head or cover 35 a single compressor governor device of the above plate 5, which members are respectively secured type, which is designed to permit supply of steam together by suitable means such as bolts. For to the two compressors at a rate sufficient to insuring leak tight joints, suitable gaskets may effect simultaneous operation thereof kat a speed be interposed between the adjacent sealing faces promoting maximum efiiciency. In this way of the various casing sections, such as a gasket 40 the work required in maintaining the main '6 which is interposed between the casing secreservoirs supplied with compressed air is tion 3 and the valve section 4, and a gasket 1 shared equally by the compressors. 'In pracsimilarly clamped between the section 4 and tice, however, it has been found that a compreshead 5.

sor governor as above described may sometimes The valve body i has formed therein a steam 45 respond to slight variations in main reservoir inlet chamber 8 and an outlet chamber 9 which pressure in such a manner as to throttle the are separated by an apertured baille wall lll havsupply of steam to the pair of compressors, with ing an annular valve seat Il. A steam valve I3 the result that one of the compressors may be disposed in the chamber 9 is adapted to enoperated for longer intervals or at a faster rate gage the valve seat Il, and is provided with a 50 than the other, particularly when one of the vertically disposed stem i4 which is slidably compressors oiers considerably greater resistmounted in a suitable bore in the cylinder secance to operation than the associated machine. tion 2 and is connected at the upper end there- In such a case the compressor '.operated most of 'to a piston I5, the upper face of which is frequently is subject to greater than normal subject to the pressure of iiuid in a chamber 55 and 23, respectively, that are formed in the. v-

valve casing 4. Secured to the lower face of the piston valve20 is a sealing element 25'wl'nlchA is adapted for engagement with an annularseat rib 26 formed in the valve 4casing 4. The diameter of the seat rib 26 is'lessfthan that of the valve piston 20, so that, with the Valve piston in seated position as shown in thev drawing, a relatively small area thereof is subjected to the pressure of fluid in a chamber 21 formed in the' casing, rwhich lchamber is adapted to be connected with the main reservoir through the medium of a pipe 28 and the usual brake valve device, not shown, when lthe brake valve device is inrunning position. A coil spring 3U is interposed between Ithe upper side of the valve piston '20 and an adjustable spring seat 3I, which vis screwed in a suitably threaded bore in the .head 5 and is provided with. a calibrated or 'restricted atmospheric exhaust passage 32.

-on a small area thereof within a chamber 39. Fluid under pressure may be supplied to chamberV 39 from the main reservoir through a pipe 40, which in standard brake systems is normally 'connected to the main reservoirs at all times. The portion of the bore 23 at the upper side l of the valve piston 2| is open to the atmosphere by way of a calibrated discharge passage 42, and, with the valve piston in a seated position as shown in the drawing, this-vented portion of the bore 23 also communicates through a groove 43 formed longitudinally in a wall of the bore, and by way of a passage 44, with a valve chamber 45 that is formed in a bushing 41-within the casing section 3.

The bushing 41 is vertically disposed within a suitable recess in the casing section 3 adjacent the gasket 6. Slidably mounted in the bushing 41 is a double check valve 56, which is normally urged upwardly into seatingengagement with the gasket 6 by the force of a coil spring 5I `for maintaining communication between the passagenl4 and aport 52 formed in the bushing and communicating by way of a passage 53 with the piston chamber I6. A gasket 54 is interposed between the lower surface of the bushing 41 and the casing section 3 and provides a seatA for the doubleI check valve 56 when it is moved downwardly against the force of the spring 5I as hereinafter explained, in which lower position of the valve communication from the passage 44 to the port 52 is cut 01T while communication is established to the port from a passage 55 leading to a groove 56 formed in the wall of`A the bore 52 and controlled by operationof the valve piston 20. i

It will be understood that the valve pisto 20 is `adapted .to serve as ar low pressure valve controlled by the load of the coil spring and operative to unseated position when main reservoir pressure in the chamber 21 exceeds a predetermined low value, with the associated air brake system in running condition, while the valve piston 2I is subject to the somewhat higher force exerted by the spring for controlling supply of fluid from the chamber 39 only when main reservoir pressure exceeds a predetermined high value, while the brake system is being recharged following an application of the brakes.

In operation, the steam valve I3 is normally maintained unseated lso as to permit free flow of steam by way of the chambers 8 and 9 in the Valve body I to the usual compressors, which are thus operated tobuild up the pressure of air inthe main' reservoir. Assuming that the associated' air brake system is in running condition, and that fluid at main reservoir pressure is thus supplied through the pipe 28 to the chamber-'1.21,'upon subsequent increase in such pressure beyond a predetermined low value, the valve piston 20 is forced slightly away from the seat rib.26,l thereby permitting the fluid pressure to act upon the greater area of the face of the valve piston to move it quickly to its uppermost position, in which communication from the groove 56 tothe atmospheric port 32 is cut olf due, to engagement of the upper end of the valve piston with the gasket 1, while fluid under pressure is supplied through the passage 55 tothe upper face of the double check valve 50. The double check valve is thereby forced against the pressure of the spring 5I into seating engagement' with the gasket 5II,y so that fluid under pressure continues to flow from the passage 55 through the port 52 and passage 53 to the piston chamber I6 at a fast rate for effecting quick downward movement of the valve piston I5 against the opposing force of the spring I1. The steam valve I3 is thus quickly forced intoengagement with the seat II for cutting4 off iiow of steam from the chamber 8 to the chamber 9 in the valve body, with the exception of a slow feed of steam by way of a restricted .passage 58 formed inthe Valve to permit maintenance of the compressors in an operative condition. Y

With the valve piston 20 in its uppermost position, and with the entire surface thereof thus exposed tothe pressure of uid supplied from the main reservoir, it will bev apparent that the compressors controlled by the governor device will remain inoperative until the main reservoir.`

pressure within the chamber 21 reduces considerably below the predetermined value at which the valve, piston was initially unseated. As the uid pressure is thus reduced, the spring 30 becomes effective to force the valve piston 20 away from the gasket 1,- whereupon fluid under pressure is quickly supplied by way of the groove 56 to the upper portion of the bore 22 at a'rate .faster :than that of flow through passage 32, so that the opposing fluid pressures acting on the pressureI Apreviously supplied l'to the chamber I 6 is` consequently vented to the atmosphere by way of the passage 53, chamber 45, passage 44, groove -43 and passage 42, so that the coil spring I1 is again enabled to force the piston I5 and associated steam valve I3 to their uppermost position,

permitting operation of the compressors to be resumed with a free, unrestricted supply of steam.

When an application of the brakes is effected, pipe 28 is disconnected from the main reservoir at the brake valve, but pipe 40, which is in communication with the main reservoir at all times, continues to supply fluid at main reservoir pressure to chamber 39. Control of the steam valve is thus transferred from the low pressure valvel double check valve 50, and thus cause positive 1 seating of steam valve I3.

The double check valve 50 will be held in its upper position by the combined action of spring 5I and the high pressure of the air therebelow. This check valve acts therefore to permit full control of the steam valve by which ever of valves 20 and 2| it is desired to have the controlling function.

The high pressure valve 2l will of course function to keep the brake system charged to the higher pressure until the brake valve of the brake system is again moved to running position to return control to the valve 25.

It will thus be apparent that I have provided an improved compressor governor device of readily assembled and inexpensive construction, which is operative to ensure full opening and closing movement of the steam valve controlling the supply of steam to the compressors, so that possibility of undesired throttling of the supply and consequent inefficient operation of the compressors is avoided.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a compressor governor mechanism, in combination, a pressure operated steam valve, a low--pressure responsive valve, a high-pressure responsive valve, each of said valves having a seated position wherein a portion of the pressure area thereof is subject to the corresponding fluid pressure and an unseated position wherein the full area thereof is exposed to the pressure' of fluid flowing to said fluid pressure operated steam valve, means for quickly equalizing the fluid pressures acting on opposite sides of each of said valves upon initial movement thereof from unseated position toward seated position, each valve being consequently operable with a. snap action in both an opening and a closing direction, and a double check valve operable to open communication from one of said low and high pressure valves to said pressure operated steam valve while closing communication to the other.

2. A steam compressor governor of the type including fluid pressure operated steam valve means adapted to control operation of the fluid compressor to maintain a low reservoir pressure at one time and a high reservoir pressure at another time, comprising a casing with low and high pressure portions each having a valve chamber adapted to be charged with fluid at reservoir pressure and a spring chamber always communicating with the atmosphere through a restricted port, low and high pressure valve elements operatively interposed between the valve chambers and spring chambers of said casing portions, respectively, each of said valve elements when in seated position presenting a small area to the corresponding valve chamber, and when in unseated position having a large area exposed to said valve chamber While establishing communication therefrom to said fluid pressure operated steam valve means, spring means in each spring chamber for urging said valve elements toward seated position, and communications controlled by said valve elements adapted to effect sudden flow of fluid under pressure from either valve chamber to the adjacent spring chamber during traverse of the interposed valve element from unseated to seated position, whereby each valve element is operable with a snap or pop action in both opening andclosing directions for avoiding throttling of the supply and release of the fluid under pressure to and from the steam valve means.

3. A steam compressor governor of the type including fluid pressure operated steam valve means adapted to control operation of the fluid compressor to maintain a low reservoir pressure at one time and a high reservoir pressure at another time, comprising a casing with low and high pressure portions each having a valve chamber adapted to be charged with fluid at reservoir pressure and a spring chamber always communicating with the atmosphere through a restricted port, low and high pressure valve elements operatively interposed between the valve chambers and spring chambers of said casing portions, respectively, each of said valve elements when in seated position presenting a small area to the corresponding valve chamber, and when in unseated position having a large area exposed to said valve chamber while establishing communication therefrom to said fluid pressure operated steam valve means, spring means `in each spring chamber for urging said valve elements toward seated position, communications controlled by said valve elements and adapted to effect sudden'flow of fluid under pressure from either valve chamber to the adjacent spring chamber during traverse of the interposed valve element from seated to unseated position for insuring quick non-throttling movement thereof, and check valve means operative by fluid under pressure supplied by either of said valve elements to said steam valve means to prevent escape of fluid by way of the inactive valve element.

RAYMOND E. MILLER.

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