US2249101A - Refrigerating apparatus - Google Patents

Description

July 15., 1941;

n. o. -wn ngmmmuiua APPARATUS Filed-'llay 14, 1938 INVENTOR ATTORNEY Patented July 15, 1941 Daniel 1). Wile, Utica, N. Y., assignor :6 Detroit. Lubrlcator Company, Detroit, Mich, a corporation of Michigan Application May'14,'1938, Serial No. 207,906

8 Claims. (Cl. 235-92) My invention relates generally to refrigerating apparatus and moreparticularly to valves for controlling the how of refrigerant medium where in the valve is controlled conjointly by the pressure and the temperature of the refrigerant medium. In valves of this nature which employ a volatile liquid charged thermostatic element relying on vaporization of the liquid for .motive power, some means must be provided to prevent chilling of the thermostatic element by the cold refrigerant medium leaving the valve. Heretofore, this has been accomplished by the use of a spacer member'of plastic material such as Bakelite, but such members have certain disadvantages such as swelling and cracking due to absorption of moisture, breakage when dropped or struck severely, and dificulty in maintaining tight joints. It is therefore one object of my invention to provide a valve structure which will eliminate these disadvantages. Another object is to provide a spacer member of simple and designates generally a thermostatic expansion valve having a base or body member 2, arr-upper or power member 3 and an intermediate or heat insulating member d. The body member 2 is hollow having an inlet means or extension 5 and.

an outlet port 6. Within the member 2 there is a lateral projecting portion l extending inward from the means 5. Through the means 5 and portion 1 there is an inlet passageway 8 which opens downward through the underface of portion 'I.- Screw threaded, as at 9, into the outer rugged construction which will effectively insulate the power element of a thermostatic ex- In the accompanying drawing, to be taken as. I

a part of this specification, I have fully and end of passageway 3 there is a hollow holding member it which receives a valve seat member ll having an orifice or port l2. A valve needle i3 cooperates with the valve port E2 to control flow of fluid therethrough, and is mounted on the lower arm of a U-shaped supporting member H by means of a nut l5. The hollow interior of the base member 2 provides an outlet chamber I6 and throughthe body member top wall I! there is an aperture l8. A bellows member I9 overlies the-aperture l8 and is sealed to the top wall I! in fiuidtight relation. The bellows member l9, at'its other end,-is sealed in fluid tight relation to a continuous annular 'lip 20 of a cup-shapedxmember 2|. The cup-shaped memclearly illustrated my invention, in which draw- Figure l is a view partly in elevation and partly in longitudinal central section of a thermostatic expansion valve embodying my invention;

Fig. 21s a detail view in perspective of the intermediate or heat insulating member of Fig. 1, but with a portion broken away to show the internal construction;

Fig. 3 is a view in partial central vertical cross-section showing .another formof thermober 2| has an aperture 22 through its base 23'for receiving a connecting pin 24. The pin 24 has a downward facing upper shoulder. 25 abutting against the base 23 of and within the cup member 2|.v The top arm 26 of the U-shaped member vI4 also has an aperture therethrough for receiving the connecting pin 24. The pin 24 is sestatic expansion valve embodying my invention;

on the centerline of the valve, Fig. 3, and at right angles to the showing in Fig. 3.

Referring to the drawing by characters of reference, and specifically to Fig. 1, the numeral .l

cured in clamping engagement with arm 26 by a lower flange 21 which may be formedby peening' over the pin end so that the U-shapedmember I4 is tightly held tothe base 23. The pin 24 has a portion.28 which projects upwardly from the shoulder 25. A bearing pin 29 is screw threaded into the upwardly projecting pin portion 28 and has, at its opposite end, a socket 30 for receiving a pin or thrust member 3|. The power member 3 comprises an inverted cup-shaped casing 132 which houses a bellows member 34 and has a lower edge portion 33 of enlarged diameter. The bellows member 34 has,

at its lower end, and sealed'thereto in fluid tight I I relation, a plate or end member 35. The plate member 35 has a central embossed portion 36 for receiving and guiding a spring 31 located within the bellows member 34. The plate member 35 also has. a central aperture therethrough for receiving a reduced diameter portion 38 of an abutting pin member 39 which is held against the plate member 35', as at 40, such as by peening sealedto a temperature sensitive or feeler bulb 44 to form a closed system. This system is charged with a temperature responsive fluid so that upon increase in temperature of the bulb- 44 the pressure in the system is increased to expand the bellows 34. Screw-threaded, as at 45, into the end p'ortionof the normal diameter at the open end of the cap member 3| is an annular plate member 46 having a plurality of apertures 41 and a central aperture 4| therethrough. Within the aperture 4| there isa guide member 48 having an upwardly facing flange portion 50 which holds one end of each of a plurality of spring fingers or members 5| against the lower face of the plate member 4. The member 49 has a flange portion 52 which overlies member 46 and may be formed, as by peening, to hold 3- 'theguide member 49 and the plurality of spring fingers 5| to the plate member 4. The guide member 49 serves to hold the external projecting the normal diameter part of the spring projects as-19,101 I 68 and has a downwardly projecting embossed.

portion 10 having a central aperture therethrough. A helical tension spring 12 has the final coil on its upper end of enlarged diameter to fit within the downwardly embossed portion 10, and

downwardly through the central aperture H in the embossed portion 70 and through the aperture 62 of the cup-shaped member 6|. At its other end the final coil of the spring I2 is of reduced diameter and is held against-the upward face of the upwardly projecting pin portion 28 by the bearing pin 29 screw-threaded thereto. The tension spring 12 surrounds the rod member 3| and holds its opposite ends in the sockets 34 and 42 The normal diameter portion I3 of the cup member 6| substantially fits the upper inside wall of the cylinder member 55 and is securely fastened thereto.

the refrigerant cooling coil and intermediate the 'portion 4| of the pin 34 in position for reciprocal movement therein in response to the'action of the bellows member 34. Each of the spring ,members 5| has one face near its free or other end portion in frictional engagement with the pin member 39, to prevent excessive transient motion or chattering which might otherwise be caused by pressure fluctuation in bellows member IS. The extreme free end of each of the spring fingers 5| is bent away from the member 39 in the shape of a hook, as at $3, to form a holding means for receiving and holding an endless helical coil spring 54. The spring 4 surrounds and holds the spring fingers II in a predetermined frictional engagement with the pin member-39. The plate member 44 serves asa stop means to limit downward expansion of bellows 34, as well as holding the guide member 4!. The intermediate member 4 comprises a thin stainlesssteel cylinder member ll which may be made from a rectangular, flat sheet by rolling the fiat sheet and welding the abutting ends together, as at 56. A ring member 51 having screw threads 58 and threaded to the body member 2 has a flange portion 58 against which the member 66 abuts. The ring member 81 also has a cylindrical portion 60 extending upwardly from the flange portion 58 and substantially fitting the interior of the member 55 which is secured thereto. The upwardly projecting or other end of the cylinder member II has securely fastened thereto a cup-shaped ring member 4| having a plurality of apertures 42, 13 extending through the bottom 84 of the cup member 4|, and whichwardly facing cup-shaped member 32 of the power means 3. The threaded connection of the I 'member 4 with body member 2 and with the power member 3 is preferably treated with a suitablethread compound to substantially preventpassage of moisture therethrough. The cupshaped member 4| has a shoulder 44' which is formed by the cap portion connecting the-normal diameter with the enlarged diameter 44. a spring holding member ".is supported by the shoulder coil and liquid refrigerant supply line to control the supply of refrigerant admitted to the cooling coil. Liquid refrigerant flows from the liquid line connected to the inlet means 5 through the orifice I2 into the chamber |6, and flows from the valve through the outlet port 6. The bellows member i8 is sensitive to the pressure of the refrigerant within the chamber l6 and the pressure therein tends to close valve needle I3 against the seat II and close the orifice I2 to further flow of fluid. The spring fingers 53 which are held against the projecting portion 4| of pin 39 ofl'er friction to movement of the valve and prevent rapid motion of small magnitude which might cause a chattering noise. The power element exerts a force tending to open the valve to flow of fluid and is usually so adjusted that it exerts sumcient force so that when the bulb temperature is slightly warmer thanthe temperature ofthe refrigerant corresponding to the pressure within the chamber It, the valve will throttle flow of refrigerant to maintain this predetermined differential. As the refrigerant passes from the liquid line through the valve orifice I! to the chamber I6 and to the lower pressure coils, the pressure is reducedand as a consequence some of the refrigerant vaporizes, bringing the temperature of the remaining liquid to a temperature corresponding to the lower pressure, as determined from the pressure-temperature curves for the refrigerant employed. This of course chills the body member 2.

The power element system comprising the bellows 36, conduit 43 and bulb 44 is charged with a predetermined amount of the same temperature sensitive fluid as that employed in the refrigerating system, and operates so that the opening force exerted by the power element is ineffective to open the orifice |2"to flow of fluid when the pressure within the chamber II is above a pre'- determined pressure. The predetermined maximum pressure opening of the valve is accomplished by using a small fluid charge invthe' power element system. This fluid charge must will operate to control the fluid pressure within the power element system, and controlthe valve operation. To'prevent this distillation from happening, the temperature of the bellows 34 must be maintained warmer than the temperature of the body 2. The flow of heat from the power .vented as far as possible, and to prevent this I have introduced my stainless steel spacer member which has a low rate of heat transfer and is not subject to changes caused by moisture absorption by the material, nor is iteasily broken and damaged if struck.

Referring to the construction shown in Fig. 3, the numeral 8i designates generally a thermostatic expansion valve having. a body member 82, a power member 83 and an intermediate or heat insulating member 84. The body member 82 is substantially hollow and has an inlet means 85 and an outlet means 88. Within the body member 82 there is a wall means 81 separating the inlet 85 from the outlet." and having an aperture in a substantially horizontal upper wall 88 in which is screw-threaded a port means 89 A plate member 92 having a central aperture therethrough overlies and issealed in fluid-tight relation with the edge portion of an aperture 90 through the top wall 9i of the body member 82. The central aperture 93 receives and is substantially closed bya needle projecting portion 98 to be hereinafter described. Surrounding the portion 93 and having a piston flt relation thereby the incoming refrigerant, and by any leakage of fluid from the-outlet 01' the valve, through the aperture 93 against the plate 92 to substantially prevent further flow of fluid through the aperture 93. A bellows member 98 overlies the aperture 90 and the plate member 92 and has its lower end sealed in fluid-tight relation between the top wall 8| of the body member 82.and the plate member 92. Tothe other end of the bellows member 94 is secured, in fluid-tight relation, an annular, outwardly extending, flange portion 95 of a cup member 98 having a portion extending downward into the interior of the bellows 94. -A small pressure chamber 91 of a volume substantially less than that bounded by the bellows itseli, is thus formed-within the bellows, having the plate member 92 forming the bottom wall of the chamber 91 and the cup member 98 forming the top wall. The chamber 91 has a connection comprising a means 91-, see Fig. 6, extending through and threaded to' the body member 82 and extending through the plate member 82 to provide means for maintaining an external pressure therein. A valve needle 98 cooperates with the port means 89 to control-flow o1 fluid therethrough. The needle 98 has an upwardly extending tip portion 98' of reduced diameter which extends through the port means 89 and .with is a cone-shaped member 93' which is urged to limit expansion 01 the bellows 98'.

aperture 98 or the plate member 92, in a piston fit for reciprocal movement therein, and substantially seals the aperture 98. The upper end of the tip portion 98- abuts against an end member I00 extending through and secured to the bottom. of the cup-shaped member 88.

The power member 88 comprises a sealed system. including a bellows member (not shown), a

capillary-tube I8I and-a ieeler bulb I82, and is charged with a temperature responsive fluid. Projecting downward from the power member 88 hereinafter described. The extreme ends of the v blades are bent away out of engagement with the member I 01 sothat a smoother engagement is maintained.

The heat insulating member v8t comprises a stainless steel cylinder I08 which may be formed from a flat sheet of metal and the adjacent ends formed as by a butt welded joint I09. A ring member H0 having a cylindrical portion III and a flange II 2 is threadedly secured, as at H2, to the body member 82 so that it surrounds the aperture 90 through the wall 9| thereof. One end portion of the steel cylinder I08 substantially flts the cylindrical portion III and is in abutting relation'with the flange H2 and may be secured in this position by any suitable means. The upper or other end of the member I08 has secured thereto the lip portion 8 of an inverted cupshaped member H8, for screw-threaded reception in the power member 88. Thebottom'or base I I8.of the member I I4 has a large concentric aperture I I1 therethrough anda pluralityoi' smaller aperturesi I8 surrounding the aperture 1. Secured to the base 8- along the periphery oi the aperture H1 and extending within the cylinder I08 is a cylinder member I01 which cooperates with the spring members I08 to dampen movement therer between. The length of the member I01 is so adjusted that it cooperates with the member 98 Preferably the threaded connections of the member 88 with the body. 82 and with the power member 88 are fllled with a suitable thread compound to substantially seal the joints against the passage of moisture therethrough. I

The operation of the valve shown in Fig. 3 is similar to that of the valve shown in Fig. 1,

. the main difference being that the pressure within 0 the bellows 98 is not thepressure oi. the adjacent chamber of the valve body. In this construction a plate member 92 separates the interior of the bellows from the valve body, and the connecting means 91' is added. The usual method oi using this valve is to connect the connecting means 91 by a conduit to the outlet'oondiiit from the cooling coil so that the pressure therein at the point where bulb I 02 is located may be communicated to the interior oi the bellows. By using this method the pressure drop through the coolin coil hasno appreciable effect on the amount of and fastened to the end wall of the bellows (not shown) is athreaded screw I08 having its downward projecting end screw-threaded. as at I04,

.intothe member I88 against which the valve needle extending portion 98" abuts, thereby oper atively connecting the power member 88 to the valve needle 98. Acup-shaped member I88,

threadedto screw I08, has downward projecting liquid admitted to. the coil because the pressure and temperature relations by which the valve operation is governed are taken at one point.

The valve operates to maintain the exit refrigerant vapor at a predetermined-temperature above the temperature corresponding tothe outlet rei'rigerant pressure. 1 v

Fig. '5 shows in detail a portion 01' a modification of the construction shown in Fig. 3. In this modification. the pressure sensitive bellows I20 is inverted with respect to the-bellows 98 of Fi 3.

A carrying member I2I having one end secured to the periphery of the aperture 90 of Fi '3 (not shown in Fig.5) carries on the other end and sealed-thereto the upper end of the bellows I20.

nd portions which hold one end or each of a To the lower end oi the bellows is sealed 8. re-

entrant cap member I22 which has aportion I28 extending within the. bellows I28. A stainless III. The side wall portion away from the lip portion I I8 is screw-threaded, as at steel cylinder I24 is sealed to an inverted cupshaped member I25 and screw-threaded, as at I23, to the power element I2'I carried by a casing I28 in a manner substantially as in Fig. 3. A concentric aperture I23 extends through the bottom wall I30 of the member I25, and a plurality of smaller apertures I3I also extend through the wall I30 and surround the aperture I29. One end of a cylinder I32 is secured to the wall I30 around the periphery of the aperture I29 and has the other end extending within the cup-shaped member I25 toward the bellows I20. A second cylinder member I33 concentric with and. surrounding the member I32 and extending in the same general direction has one end secured to the wall I30 and has the other end extending within the upper open end of the bellows I20 secured to the carrying member I2I to serve in cooperation with the reentrant cap member I22 as a stop means limiting contraction of the bellows I20. The power element H1 is operatively connected to the cap member I22 by means of a rod I34 screw-threaded, as at I35, into a thimble member I38 which is secured in an aperture I31 through the reentrant portion I23 of the member I 22, and which may be secured by peening, as

p at I39. The thimble member I33 is operably connected to the valvemember (not shown in this figure) by a rod I60 which abuts the member I36. Secured to the member I36 on the power element side of the cap member I22 is the base of a pair of spring fingers Ill. The free end portions I42. of the fingers Ill frictionally engage the inner walls of the cylinder I32 to dampen the movement' of the thimble member I 36, which would otherwise occur with small rapid changes of pressure to which the bellows I20 is subjected. The extreme free ends I63 oi the fingers MI face inwardly, however, and do not engage any surface. Anut I45 may be screwthreaded to the rod I36 to secure the base of the spring fingers Hli to'the thimble member I33.

It will thus be seenthat I have provided a valve which is simple, rugged and dependable.

What I claim and desire to secure by Letters Patentof the United States is: 1. In a thermostatic expansion valve, a body member having an opening through a wall thereof, a pressure responsive member sealing said opening, an end member secured and sealed to said body member around said opening, a casing member, a thermostatic power element operating member positioned in said casing member, thrust means operatively connecting said operating member and said responsive member, a connecting member secured and sealed to said casing member and having a portion projecting toward and concentric with said end member, the adjacent portions of said projectingportion and of said end member being or substantially equal size, and a thin sheet metal housing member of low heat conductivity positioned between said adjacent portions, said housing member being sealed in fluid-tight relationship at either end to the respective adjacent portions of said connecting member and of said end member.

2.. In a thermostatic expansion valve, a. body member having an opening through a wall thereof, a pressure responsive member sealing said opening, an end member secured and sealed to said body member around saidopening, a casing member, a thermostatic power element operating member positioned in said casing member, thrust means I operatively connecting said operating member and said responsive member, a supporting member having opposite end portions, one end portion conforming to and fitting said end member to provide a sealed joint, the other of said end portions inclu g a cup-like portion having an aperture through its end wall for receiving said thrust means,

the side wall of said cup-like portion being secured and sealed to said casing member, an intermediate continuous oi! said supporting member positioned between end member and said casing member being of metal of low heat conductivity thereby to maintain a differential of temperature between saidcasing member and said body member.

3. In a thermostatic expansion valve, a body member having an opening through a wall thereof, a pressure responsive member sealing said opening, an'end member secured and sealed to said body member around said opening, a casing member, a thermostatic power element having an operating member positioned in said casing member, thrust means operatively connecting,

said operating member and said responsive mem: ber, a cup-like member secured to said casing member and having a central aperture therethrough and having a portion projecting toward and concentric with said end member, a spring member extending through the aperture in said cup-like member and having one end supported by said cup-like member, the adjacent portions of said projecting portion and of said end member being of substantially equal size, and a thin sheet metal housing member of low heat conductivity positioned between said adjacent portions, said housing member being sealed in fluidtight relationship at either end to the respective adjacent portions of said cup-like member and of said end member.

4. In a thermostatic expansion valve, a body member having an opening through a wall thereof, a pressure responsive member sealing said opening, an end member secured and sealed to said body member around said opening, a casing member, a thermostatic power element having an operating member positioned in said casing member, thrust means operatively connecting said operating member and said responsive member, a cup-like member secured to said casing member and having a central aperture therethrough and having a portion projecting toward and concentric with said end member, a spring member extending through the aperture in said cup-like member and having one end supported by said cup-like member, the adjacent portions of said projecting portion oi said end member being of substantially equal size, a thin sheet material housing member of stainless steel positioned between said adjacent portions, said housing member being sealed in fluid-tight relationship at either end to the respective adjacent portions'of said cup-like member and of said end member, guide means secured to said casing member and extending toward said body member and operable to guide said thrust means, and friction means secured-to said guide means and operable to frictionally oppose movement of sail thrust means.

5. In a thermostatic expansion valve. a body member having an opening through a wall thereof, a pressure responsive member sealing said opening, an annular ring member secured and sealed to said body member around said openlng, an annular flange portion on said ring member, a casing member, a thermostatic power elepart portion projecting said ring member,

ment having anoperating member positioned in said casing member, thrust means operatively connecting said operating member and said responsive member, a connecting member secured and sealed to said casing member and having a toward and concentric with projecting portion and of said ring member being the adjacent portions of said of substantially equal size, and a thin sheet mate:

rial housing member of stainless steel positioned between said adjacent. portions and having one end abutting said annular flange portion, said housing member being sealed in fluid-tight relationship at either end to the respective.adjacent portions of said ring member and of said connecting member, said connecting member bottom portion serving as a reenforcing means for said housing member.

6. In a thermostatic expansion valve, a body member having an opening through a wall thereof, a pressure responsive member sealing said opening, an end member secured and sealed to said body member around said opening, a casing member having a portion of normal dimeter and a portion shoulder on said intersection of said normal diameter portion and said enlarged diameter portion, plate means secured to said shoulder and having an aperture therethrough, a power element .carried by .said casing member and' having an operating memof enlarged diameter, a casing member formed by the ture therethrough secured and sealed to said.

7 being sealed in fluid-tight relationship at either an operating member said opening, a casing casing member and having a lip portion projecting toward and concentric withsaid end member, the adjacentportions of said lip portion and of said end member being of equal size, a thin sheet metal housing member positioned between said adjacent portions, -said housing member *end to the respective adjacent portions of said her, thrust means extending through the plate means aperture and operatively connecting said operating member and said responsive member, spring fingers secured to said plate means and irictionally en ing said thrust means to dampen movement thereof, a supporting member having opposite end portions, one end portion conforming to and fitting around said end member to provide a sealed joint, the other of said end portions being sealed to said casing member, an intermediate continuous part of said supporting member being member and said casing member and being of thin low heat conductivity metal thereby to maintain a temperature differential between said casing member and said body member.

, blows secured and sealed ment resilient heat insulating metal member of low end member and of'said cup-like member, a cylinder member secured to said cup-like member concentric with the aperture therethrough and extending toward said body member, and spring fingers secured to said pressure responsive member 'and frictionally engaging said cylinder member to 'frictionally oppose movement of said responsive member. v

8. In a thermostatic body.

expansion valve, a valve 9. pressure responsive valve operating elecarried by said body, a thin wailed'tubular heat conductivity capable of withstanding sharp at one end to said body and surrounding said element, a cup shaped supporting member having a side wall portion fitting within and secured to the other end of said tubu lar member, said supporting member having a cylindrical screw-threaded side wall portion extending beyond said tubular member, a. thermostatic power element having a casing with a screw-threaded flange threadedly engaging said positioned between'said end cylindrical portion, and means for transmitting movement from the movable member of said thermostatic power element to said pressure responsive element.

- DANIEL D. WILE.

member sealing said secured and sealed to power element having

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