US1579782A - Regulator for variable-capacity compressors - Google Patents

Description

A ril '6 1926. 1,579,782

M. RIESNER REGULATOR FOR VARIABLE CAPACITY COMPRESLSORS Fil ed Sept. 1 1925 5 Shets-Sheet 1 April 6,1926. 1,579,782 M. RIESNER REGULATOR FOR VARIABLE CAPACITY COMPRESSORS Filed p 19 1923 4 3 sheets sheet 2 wuamtoz %ey{w m April 6 192 6. 1,579,782

I M. RIESNER REGULATOR FOR VARIABLE CAPACITY COMPRESSORS Filed p 1925 5 Sheets-Sheet 5 uve/htoz Patented Apr. 6, 1926.

MICHAEL RIESNER, OF CINCINNATI, OHIO, ASSIGNOR 'IO WORTHINGTON PUMP AND MACHINERY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF VIRGINIA.

nnoum'ron non vnnmnrs-onr'norrr comrnnssons.

iApplioation filed September 19, 1928. Serial No. 663,540.

To al whom. it may concern:

Be it known that I, MIOI-IAEL'RIESNER, a citizen of the United States, residin at Cincinnati. county of Hamilton, and tate of Ohio, have invented certain new and useful Improvements in Regulators for Variabl'e-Capacity Compressors, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This int'ention relates to a novel regulator for variable capacity fluid compressors the especial object of'the invention being to rovide an apparatus of this type whlch s all he more certain in action, especially under small changes of receiver pressure, and further to provide an apparatus operating with less friction and securing a higher compressor efficiency than those heretofore employed.

In constructions embodying the present invention, I employ a series of control valves, each acting to control a partial unloading of the cylinder, so as to vary the cylinder capacity-in accordance with the number of control-valves operated, and the required operation of these control valves-is secured by a governor acting to' vary the relative pressures tending to move these valves in opposite directions, for unloading or loading the cylinder. The control valves preferably are moved into unloading position byreceiver pressure and into loading position by spring pressure acting against.

the receiver pressure, and a governor controls the valves by decreasing or increasing the spring pressur to the extent necessary to permit their movement by the receiver pressure for unloading, or to move them against the receiver pressure for loading the cylinder. The invention also includes certain features of construction and combina tions of parts in a-variable capacity fluid compressor apparatus, as described hereafter.

For a full understanding of the invention, a detailed description of constructions embodying the same in preferred forms will invention then specifically pointed out in t-heclaim's. y

now be given in connection with the-accompanying drawings forming a part ofgthis specification, and the features forming the the drawii1gs- 1 a eas. arnes ess de-awe tion of a single compressor cylinder embody mg the invention, with four-unloading steps secured by three unloading devices;

Figure 2 is a lon itudinal section of the cylinder on the line of Fig. 3;

Figure 3 is a cross section of the cylinder onthe line 3 of Fig. 1;

Figure 4 is an enlarged view of the control apparatus for the unloadin devices, similar to Fig. 1, but partly bro en away to show the construction;

Figure 5 is a vertical section of the control 'apparatus;

Figure 6 is a cross section on the line 6 of Fig. 4;

Figure 7 is a detail view of my improved unloading valve:

Figure 8 is aview similar to Fig. 4, with the control valves in section, and showing a modification.

Referring now to the drawings, and especially to Figs. -1 to 7, A is the compressor cylinder, B the piston, C the piston rod driven in any suitable manner, D, D and E, E inlet and discharge valves at, respectively, the crank and head ends of the cylinder and F a clearance pocket for the crank end of the cylinder, automaticall controlled by the unloading apparatus. wo handcontrolled clearance pockets G at the head end of the cylinder are shown for control ling maximum loading, but it will be understood that these may be omitted or a different. number of hand-controlled devices be used. The suction and discharge valves are shown as of a type of plate valve now well known and patented by United States Letters Patent to Meyer Reissue No. 13,991

and No. 1,341,413, :0 that no furtherde' scription of these valves per se need be given. Each of the inlet valves D, D is provided with pressure-operated means for unseating and holding 0 en the'inlet valves, this means consisting o a sliding member 10 carrying fingers 11 adapted to engage the plate valves a, the member 10 being moved to open the valves-by pressure operated piston 12 and returned to release the valves for normal operation by spring 13. The port connectingF the cylinder with the clearance chamber -is controlled. by. a valve 6 actuated by ressupe operated piston 14, which is moved y receiver pressure to open the valve for connecting t e cylinder with the chamber and partial unloading,

and is closed by a spring which, compound compressors, pre erably is aided by intercooler pressure transmitted outside the piston through pipe 16. The valves controlling the clearance chambers Ur are shown as hand valves 17 of common type operated by screw stems and hand wheels 18.

Referring now to the apparatus for automatically controlling the pistons 12, 1% and valves a, 5, pressure is applied to the 1nner side of piston 14 'to open the clearance valve for the first unloading step, by receiver pressure transmitted through pipe 1. Pressure is applied to the outer side of piston 12 to open inlet valves D at the crank end of the cylinder for unloading steps 2 and 4, by pressure transmitted through pipe 2 branched to each inlet valve. Pressure is applied to piston 12 for opening inlet valves D at the head end of the cylinder fpr the third unloading step by pressure applied by pipe 3 branched to each inlet valve. Pressure in thesepipes 1, 2, 3 is controlled by wing valves 9, k, i mounted in valve casings 19 on the cylinder and acting to connect the pipes 1, 2, 3 with pressure chambers 5 supplied by pressure pipe 20 connecting with the receiver or other suitable source of pressure fluid, or to connect these pipes 1, 2, 3 with exhaust through exhaust chambers 21 exhausting by wing stems 51 according to the position of the valves. Each of these valves 9, k, i is normally held in position to connect pipes 1, 2, 3 with exhaust chamber 21 for full loading of the compressor cylinder, by spring acting upon the valve stem 51 through cross-bar 52, the spring pressure preferably being adjustable byrscrew rods 53 threaded in blocks 54 carrying one end of the springs and provided with thumb nuts hearing against cross-bar 52 for adjust ing the screws. The other ends of the springs 50' are connected to rollerbars 56 sliding in gui'de slots in guide bar 57 and normally held depressed by a slide 7' engagmg loose sleeves on the roller bars, so that the tension of the springs is decreased by the retraction of the springs or release by the wedge. A single slide 7' may be used forthe control of all the valves, but in theconstruction shown in which the operation of one of the valves is to be reversed to provide unloading steps in excess of the number of unloading devices, it is preferable to divide the slide into two parts 3;, controlling the valve h as after.

The slides j,

explained here- 7" are both formed with an inclined or wedge surface 6 acting to gradually release and engage the roller-bars 56 on slight movement in opposite directions, and the slide 3'', for the purpose of producing a second operation of valve h, is cut-out-intergietl ate its ends to form wedge surfaces in such unloading devices,

the slide M .of unloading through the ferent heights,

The slides j, j are actuated to-control the spring pressure and thus the valves 9, I, z for unloading and loading, by apparatus controlled by the receiver pressure, as usual and this receiver pressure and the operation of the valves is preferably secured through a pressure-operated member controlled directly by the receiver pressure, and the pressure fluid is controlled by a pilot valve, which pilot valve is controlled directly by the receiver pressure, and the pressure'fiuid controlled by the pilotvalve and actuating the slides j, 7" may be of any suitable character and taken from any suitable source, thus enabling the apparatus to be controlled by slight variations in receiver pressure while employing pressure as heavy as desired for actuating the slides 7', j. As illustrated and preferred, there is employed for actuating the slides 7', 7" a governor or regulator of the well-known Mason regulator type, and, as shown, the slides j, j are connected by arms 23 to the rod of piston 2 1- moving in cylinder 25 having fluid passages 26, 27 connecting with opposite ends of the cylinder, these fluid passages being controlled by a pilot valve (2 in valve chamber 28 with which connect fluid passages 29, 30 for inlet and exhaust of pressure fluid, the pilot valve (1 having-a passage through it for connecting the passage 27 with exhaust 30, when the pilot valve is raised to connect pipe 26 with inlet 29, as usual in such constructions. The pilot valve d is shifted by lever 31. connected by link 32 to weighted lever 33 pivoted at 34 and bearing on diaphragm 35, which diathrough pipe 36. The pilot valve d is returned to position after each movement, for

unloading step on a further increase purpose a compensating device of the usual type is used in which lever 31 is pivoted on one arm of bell-crank lever 37 instead of at a fixed point, and the other arm of the bellcrank lever 37 is connected by a link 38 to one arm of bell-crank lever 39, the other arm of which engages a wedge 40 moving on shdeway 41 and connected by link 42 and arm 43 to the rod of piston 24 sans to move therewith. sating device is similanto the well known ason regulator with compensator, except 'for the following feature:

It is important that the piston 24 should phragm is subjected to receiver pressure This regulating and compen-- move in exact steps and thus secure an exact Y movement of the slides j,

j at each step, as an irregular movement of the piston 24 might not secure the desired accurate control pipes 1, 2, 3. For the purpose of securing this result, the wedge 40 is formed in horizontal portions of difwith sharp inclined steps be-' roller-bar 56 of valve 9 controlling pipe 1,-

tween them. Each of these inclined steps. therefore, definitely fixes the point in the movement of the piston2-t at which the pilot valve will be shifted to return'to its normal position and stop the piston 2%, thus assuring the accurate positioning of the slide to control the valves g, 11,21 and thus the pressure in pipesl, 2, 3 and their unloading devices.

The operation of the construction-shown in Figs.. 1 to 7, and above described, is as follows: Assuming that the compressor is operating at full capacity, an increase of receiver pressure above that for which the apparatus is set raises lever 33 and pilot valve (1 so as to admit pressure. fluid from pipe 29 through the pilot valve and passage 26 to the left end of cylinder 25 and connect the other end of thecylinder through passage '27 and the centi'ii hole through pilot valve 01 to passage 30. for exhaust, and thus the piston 24 is moved to the right in Fig. 5 to ivith'draw the wedge j from contact-with thus decreasing the pressure of the springs '50 controlling this valve and permitting the receiver pressure acting on this valve through pipe 20 and chamber 5 to connect chamber 5 with pipe 1, when the pressure fluid in pipe 20 will .pass through pipe 1 to the inner side of piston 14 and open valve 12 to connect the cylinder with clearance chamber F. This clearance chamber preferably will be 'made of such capacity as to unload the crank end of the cylinder'A one-half, that is, a one-fourth unloading of the cylindcr, so that the latter will operate at 7 5% capacity, assuming that the hand-controlled clearance pockets G are closed. The compensating device now returns the pilot valve (l to central position, as shown in Fig. 5,

preventing inlet or exhaust of motor fluid to cylinder 25 and stopping the piston 24 in this position.

On a further increase of receiver pressure, the same operation is repeated, the slides j, j being moved another step, on which movement slide j by wedge 6' releases the roller-bar 56 of valve h, and this valve h is. moved by the receiver pressure to admit re-- ceivcr pressure from pipe 20 to pipe 2, and thus unseat the inlet valves end of the cylinder, thus fully unloading the crank end of the cylinder so that the compressor operates at 50% capacity,

On a further increase of receiver pressure, another movement of the slides j, 7" takes place and the slide releases cross-bar 56 acting on the spring of valve 2' so as to secure the movement of the valve and admission of pressure fluid from pipe 20 to pipe 3. while by the same movement he slide j'by wedge '6 controlling the. springs of valve. h so as to increasetthe. spring. pressure on. valveh and restore. it to normal position, in *tthiclr pipe D at the crank acts. on roller-bar 58 4 2 is closed to pressure pipe 20 and open to exhaust 21. Thus the inlet valves D at the crank end of the cylinder are released and these valves reseated for normal operation, and the valves D at the head end of the cylinder unscated for unloading the head end,-

and thus the crank end of the cylinder is unloaded one-half by the clearance chamber F and the head end of the cylinder fully unloaded, the compressor thus operating at 25% capacity.

On a further increase of pressure and movement of'the slides. j, j, the slide j, by wedge 6, releases the roller-bar 5G to decrease the pressure of the springs controlling valve h, and pipe 2 is again opened to pressure pipe 20, so that the inlet valves E at the crank end of the cylinder are held open'for unloading, completing the unloading of the cylinder.

Decrease in receiver pressure permits the weighted lever 33 to fall and reverses the above operation in successive steps. the compressor being gradually loaded from full unloading to full capacity by movement of the slide j to the left in Fig. 5, first by connecting pipe 2 to exhaust 21, for 25% ca pacity then by connecting pipe 2 to pressure pipe 20 and pipe 3 to exhaust for 50% capacity; then connecting pipe 2 to pressure pipe 20, for/75% capacity; and finally con- G and valves 17 the opening of either or both of which increases the cylinder clear- 'necting pipe 1 to pressure pipe 20 for closing I ant-e to the extent desired, the clearance chambers G being made of any desired capacity, according to the maximum loading limit to be provided for. The automatic unloading devices then operate on a cylinder capacity reduced bythe maximum control chambers G.

' The construction shown in Fig." 8 is the same, and the operation the same. as that described above in connection with Figs. 1 to 7, except that this construction is designed for use with a compressor having an unloading dvicefor' each step, so that no. reversal otaction of any unloading device is necessary during unloading or loading. The construction illustrated-is for a compressor cylinder having four unloading devices,

there being shown 'four valves m, n, 0 similar to valves g,h, 2' previously described, all ofwhieh are mounted-in a single-valve cha1nber45, and each of which controls its corresponding pipe 11, 2,. 3, .4, leading to theditferent unloading .ideyices. -.With these valves thus mounted,-only the one part slide is required,the operation of this slide and friction, and the valves are controlled and The receiver sure on the'operatmg piston the valves being the same as previously de-- scribed in connection with slide j. It will be understood that the unloading devices used may beef any suitable number and form, the valves controlled by the slide 9' coacting with said unloading devices in any suitable manner to secure the desired opera-- tion.

Itnvill be seen that my improved regulator secures important advantages, espe-' cially in connectionwith variable capacity compressors, in that a full and quick movement of the control valves is secured, the action is certain and practically without 3 a very narrow range of pressure, so that a very close regulation and one practically independent of maximum and minimum pressures in'the receiver is provided. The construction, moreover, is very simple, durable convenient of adjustment and repair. pressure acting on the pilot valve diaphragm is required only to remove the small balanced pilot valve,.and the presactuating the control valve wedge, is required only to move the wedge against the friction of the spring roller so that this pressure also may be quite light. The spring pressure on thevalves may readily be adjusted and the slide d to release this pressure to any 8X7,

arrangi Y tent daired, sothat on such release the receiver pressure acts quickly andwith certainty to "secure the full movement of the valves, andsdmission of'full' receiver pressure to the nloading devices.

- In such unioading apparatus it has been found 'difiicult to provide a pressure-operated unloading,

valve controlling a clearance chamber, in which leakage of pressure past should not stick the piston or valve is avoided, while the certain action of the unloading device and the efliciency of the compressor, especially at full capacity, depends upon the piston and valve being non-leaking. Leakage at the piston arises especially from the fact that the piston. hasvery little motion, and this motion in many cases is infrequent,'so that piston rings have no chance to wear down, and other forms of packing are liable to leak after prolonged disuse, or to stick so as to interfere with the operation of the piston.- It is ifiiportant'also thatthe piston or valve and thus interfere with the compressor control. I have provided a clearancevalve and operating piston construction which secures the desired results, which construction maybe applied, also, in connection with pressure-operated valves for other uses. a As shown in Fig. 7, the piston 14 acting to operate. the clearance valve, is formed suitably secured together,

with'two cups 7 of suitable thin flexible metal between them, the flanges of these cups being turned in opposite directions alongthe outer side of the piston. ,Thcse cups referably are made of sheet brass,'but may e made of any suitable metal. A single cup may be used with advantage, but the best results are secured with two cups arranged as shown, and it has been found in practice that such piston is absolutely tight and moves freely, notwithstanding that the piston may not be operated for a considerable time. The perfect seating of the valve so as to make it non-leaking, is secured by attaching the valve to its stem 8 byjwhich the piston 14 operates it, by a flexible connection as distinguished from connecting the valve rigidly to the stem. In the construction shown, the valve 6 carries a cap 9 having a recess receiving a head on the piston stem 8, which head and recess are so formed as to permit the slight tilting of the valve 6, thus securing its perfect seating independently of the piston alinement. Any other suitable flexible joint between the piston stem 8 and. valve d securing the same results may be used.

It will be understood that the invention a is not limited to the specific form or arrangement of devices illustrated, but that 95 the invention, as defined in the claims may be embodied in various constructions.

What Iclaim isz' 1. In a variable capacity compressor, the combination with the cylinder, and a plurality of unloading devices, of separate control valves and fluid connections for the respective unloading devices, said control valves being subject to constant pressure tending to move them into loading position, and a membercontrolled by receiver pressure acting to vary said constant pressure on said control valves successively to control said unloading devices for unloading and loading the cylinder.

2. In a variable capacity compressor, the combination with the cylinder and a plurality of unloading devices, of separate control valves and fluid connections for the respective unloading being subject to spring pressure tending to move them in one direction, and a member controlled by receiver pre:sure and acting to vary the spring pressure on said valves successively to control said unloading de- 120 vices for unloading and loading the cylinder.

3. In a variable capacity compressor, the combination wth the cylinder and a plurality of unloading devices, of separate control 125 valves and fluid connections for the respective unloading devices, said control valves being subject to spring pressure. and fluid pressure tending to move the valves in opposite directions, and a membercontrolled devices, said control valves by receiver pressure and acting to vary the spring pressure to secure the movement of said valves successively to actuate said unloading devices for unloading and loading the c inder.

4. n a variable capacity compressor, the combination with the cylinder and a plurality of unloading devices, of separate con-v trol valves and fluid connections for the respective unloading devices, said control valves being subject to spring pressure tending to close the valves and receiver pressure tending to open the valves, and a overnor controlled by receiver pressure inc luding a slide controlling the spring pressure on the valves and moved by' the governor to vary, the spring ressure to secure the movement of said va ves successively to actuate 'said unloading devices by the receiver pressure for unloading the cylinder and against the receiver pressure for loading the cylinder.

6. Ina variable capacity compressor, the combination with the cylinder and a. plurality of unloading devices, of separate control valves and fluid oonnections for the respective unloading devices, said control valves being subject to spring. pressure and fluid pressure tending to move the valves in opposite directions, and a overnor including a'pilot valve controlled y receiver pressure and a member actuated by fluid pressure controlled by said pilot valveand acting to vary the spring ressure to secure the movement of said va ves successively to actuate said unloading devices for unloadin and loadin the cylinder.

In a varia le capacity compressor,-the

combination with a cylinder and a plurality of unloading devices, of -se arate control valves and fluid connections or the respective unloading devices, ,and pressure con-- "including trolled governor mechanism, means for successively actuating said control valves to bring said unloading devices into actionand acting to bring one of said devices into action a plurality of times duringea'ch of the cylinder unloading and loading 0 rations.

-,8. n a variable capacity compressor, the combination with a cylinder and a plurality valves and of unloadin devices, of separate control uid connections tor the respec. tive unloading devices, and pressure controlled governor mechanism, including means for'successivelv actuating said control valves and acting to unload one end of the cylinder by a plurality of steps and to load said end for an intermediate unloading step.

9. In a variable capacity compressor, the combination with a cylinder and a plurality of unloading devices for the cylinder, including a single clearance chamber, of separate control valves and fluid connections for the respective unloading devices, and pressure controlled governor mechanism for partially unloading the cylinder by said clearance chamber and then fully unloading the cylin-- der by unloading steps secured by discharging the fluid through the suctionvalve ports at one or both ends of the cylinder.

10. In a variable capacity compressor, the combination with a cylinder and a plurality of unloading devices for the cylinder, including a single clearance chamber, of separate control valves and fluid connections for the, respective unloading devices, and pressure controlled governor mechanism for partially unloading said cylinder by said clear I tion during another step, and again holding said valves open for a later step.

11. In a variable capacity compressor, the combination with the cylinder and a plurality of unloading devices, of separate control valves and fluid connections for the re spective unloading devices, said control valves being subject to spring pressure tending to move them in one direction, and a governor controlled by receiver pressure, including a slide controlling spring pressure on the valves and moved by the governor to vary the spring pressure to secure the movement of said valves successively to control said unloading devices for unloading and loading the cylinder, said slide being formed to secure the movement of one of said valves a plurality of times during each of the cylinder'unloading and loading operations to bring one of the unloading devices into action a plurality of times during each such,

operation.

12. In a variable capacity compressor,

including a pilot valve controlled by receiver pressure, compensating devices for returning the pilot valve to position after the combination with a cylinder and a plurality l2 5 each movement, and a stegped wedge actuating said compensating evices, said steps acting to definitel fix the successive movements of the mem er controlled by the pilot valve.

13. The combination with a fluid control valve, and a movable member controlled thereby, of compensating devices for returning the valve to posltion after movement, said compensatin devices including a Wedge provided witi steps controlling the compensating action to fix the movement of the member at each action of the valve.

14. The combination with a fluid-control valve, and a movable member controlled thereby. of compensating devices for returning the valve to position after movement, said comgensating devices including a series of stops rought into action by the successive movements of the movable member and controlling the compensating action to fix the move ment of the member at each action'of the valve.

15. The combination with a valve subjected to spring pressure tending to move itin one direction, of a governor device having a movable slide holding said spring under tension and acting to vary the spring pressure b its movement to secure the movement of t e'valve.

16. Ihe combination with a series of valves sub'ected to spring pressure tending 'or decrease the spring pressure.

18. The combination with a series oi valves, of springs and connections for holding said valves under pressure, bars attached to the'springs, and a sliding wedge engaging said bars and acting to move the bars to increase and decrease the spring pressure on the valves successively.

19. The combination with a series of valves. subjected to spring pressure tending to move them in one direction, of a governor device having a member acting to hold said springs under tension and controlled by the governor to vary the spring pressure on the different valves successively to secure their successive movement.

In testimony whereof, I have hereunto set my hand.

\ MICHAEL RIESNER.

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