US2508309A - Compressor - Google Patents

Description

y 950 R- L. TWEEDALE 2,508,309

COMPRESSOR Filed Nov. 15, 1945 2 Sheets-Sheet 1 IN VEN TOR.

May 16, 1950 R. TWEEDALE COMPRESSOR 2 Sheets-Sheet 2 Filed NOV. 15, 1945 INVENTOR.

Patented May 16,1950

R lph L- Twe dele. i ghemM t signnr;

o Vi'ckers Inenrmre ed, Dethoit; Mich-i, ttorporation ofMichigan I 7 Application. November 15, 1945,,Se i 1 Nm628i95 5 Claims.

This invention reltjtes to. fluid pressure energy. translating devices.

The invention is mere narticulahly concerned.

with a fiuidpressure energy translating device of Warieble displacement, and particularly adapted,

. IPOIY'USSE as a gas compressor.

It is an objector the present inventionto pro. vide a,- eompressor particularly adapted for re frigeration and which has a variable volumetric dish e e en Itis also. an, object to provide a: campressor of this type inwhich the cleananoe; volume is kept at a minim-hm and; which further-more: is. ma ta ne at that min mum nd p ndent y of changes in volumetric; displacement of the corn- DFQSJSOI";

It: is, also; anfobfiect to provide a, compressor of; this type which maybe construeted from elements manyioiwhich are similar: to; those eurrently in; successful use as fluid pumps and mo- QliS'. in; the hy raulic new r transmi s on ldi and particularly thnsejoi; the't-yne utilizing: a: rotatin cyl nder-berrei wihz. axial, p sto s w ic are: driven from. a drivin flan e re eteble 0h: anfaXiS" inclined to the axis: ofr ta i n ofhe cylinder. barrel.

A'furth r object: oi th i vent eni s 0 hmvi ine mpr sor, of this cla s e improve luhri eatin System: whi h w ll insure adequ e nrese sure: lubrication; to all moving; -part of the mechanism and whi h pref rably de e not. re-- quir he useof e' epare e luhr' neip mpi noth r bi ctiis to provideime; o r sser of this class an improved shait sealing; meanswherein a body, of lubricating fluid: is maintained djac n he: Shaft at he. pointwhererit x nds hr u h th hous n Of the e m e s r whithlubricating fluid is sealed both iron-r the ogtside: of the housing and; from the-inside mace-which. contains: refri erant Eurther objects and advantages of thepresent. inventi n will .besappar nt from theaf l n d scription,reference-being had to the aeeompanyh ing; draiivings= wherein; a. preferred form of the present; inventien is :clearly shown;

In the drawings:

Figure 1 is, a longitudinal; sectional view ofa, ar ab e di place ent comp es or embodyin e prefierred formiof the present invention,

Eigurezisan end View, partly in section, of theeompressor shown in Eigurel.

E unewsen-en i w ofthe.;,v. eot he om: pressor, ,pairtly; in; section" 'F euree the a sid v w; of h yo sh wn: in-

.part ment 25 between them and Q the shrfaee. 44.. beingv of; sl than thatesurfaceufl Alon igure 5 is thQ P E -Qf; he yoke; she-m ih Figure 2. Ei ne e is, the diagr matic. view; shewi z typical ef ee a e ircu t emhe yihe th pressor of Figure,1 w F g i em n ary see ehe View i e unn on; con t uct o t rmih per tof the: Wine pressor structure,

Referring. now! to i Figure 1, there, is, illustr te e mus ng I e heee y'er 11.2, an y with a shaft r ee vl heio enihe 1 4,. A dr l'fiiex endsj u th heni ne A. .d QnbalL bearings: 181 and 2 k Sui epmvide at zz ehda 4 te ter-m ,i

' in w en he bearing Wi mounted- The haf B s ere; vided with a driving flange 26, earrying a phi? rality preferablll an, add: n mhe hf bel eeele 28. w ch el end d t n ehtih ds 3! r are artic lated. Ea heQnnee-ti node! ter eeet' its opposite ballendlapi'ston 32 t eiv'otally meunted in the-ease s e wi e n oke member fi lflhevine twe er er 'iil wh are pivoted to the housingmoneitll er-i sideo f, haft .op mne 14 by m an- 1 f nn i'ons 31 (E u es nd. 7'), The cente of). the tru 3 and the axis. about hiehthe. yelie 34 tan ent; the. circle ne which the centered the s c tsizfl' are d pos dh The okfi vided with a cent l r nsrerse hl eki s etii wh ch n t th t ii -end terms the in e e flet d sh valve plate- 49.. valve pla 1s ph l id d-withflet ennuhreeel m Surfaces 42 wanton it l i en vxieh ifeeeets eater a ea; i v 4, ee e hesut face 44 is. a cylinder; barjrellfi} having efljplnrality. of cylinders- 43; therein linewhieh the ;pis%t on s 32 are sl eh y monhted. The y insl i 48 extend straight; th 'Qh hz to: the eyiinder \b' r l fr mend t end 59 hat the. hea e 9? pie: e I 3 e hrmeth ver c se y: te-th -Neht place surfaee 44;,

T c li der. r el 46. i PiY9i l;- m unted on. a bal bearing, 50 ha ried, th eey ndea mounting pin, 52. The latter e acentralv ,hole of; valve plate .494 cle a ce and el oith ue h l 3.8 provided witha, see (in, At 1e 1; the pin- 52;,carrie5a isten 58 aleq provided l 69 a d e ab e n nler formedinthe-bloph3 A ightlsgrin e p tonfih p n-"52,1 beerih '1-5i -'eh barrel 4.6; into contact with he: -y lye ple ie ii The lin erl z lhe ,A-li e hneet d l o r tate in unison with shaft I 6 by means of a Cardan shaft 66 having universal joints 68 and 10 at its opposite ends. The ends of the shaft 66 are spherical and abut against spherical sockets 12 and 14 which are mounted in bores 16 and 18, respectively, in the cylinder barrel 46 and shaft I6. The spherical abutment 14 is slidable in the bore 18 and is urged to the left by a spring 80, while the abutment 12 rests against a shoulder 82 in the cylinder barrel 46.

The yoke 34 is provided with an extended arm 84 which is pivotally connected by means of a link 06 with a rod 88 of a piston 90. The latter is slidably mounted in a cylinder 92 formed in the housing I and provided with an end cover 94.

Referring now to Figures 2 through 4, the valve plate 40 is provided with arcuate inlet and outlet ports I00 and I02 which extend through the Valve plate from side to side. .The ports I00 and I02 extend into the block 38 of yoke 34, the inlet port I00 extending through to the exterior of block 38. The discharge port I02 intersects a large bore I06 forming an oil separator and does not extend beyond the bore to the exterior of the block 38. The bore I06 is provided with concent'ric sleeves I I0 and H2 to facilitate the separation of oil from refrigerant being delivered from the discharge port I02. The sleeve II2 provides an uptake pipe leading to a discharge connection I I4 formed in a stationary pintle I I6 mounted on the block 38. The pintle II6 forms a pivotal support for one element H8 of a combined telescoping delivery pipe and thrust reaction device. The other member I20 of the device (see Figure 2) is pivotally mounted to the housing I0 by a similar pintle I22 which form the external delivery port for the compressor.

From the bottom of oil separator chamber I06, a; passage I24 leads to the bore 62 in which the piston 58 is slidable. The pin 52 is provided with an internal passage I26 leading from the cylinder 62 to the right-hand end of pin 52 and the chamber I 28 formed at the center of cylinder barrel 46. From the chamber I28 a plurality of short radial passages I30 lead to each of the cylinder bores 48. Each piston 32 is provided with areduced diameter portion I32 of sufficient length to maintain contact with the passages I30 in all positions of the piston 32. Each piston 32 is provided with a passage I34 leading from the groove I32 to the socket portion of the piston. Theconnecting rods 30 are provided with central passages I36 extending from end to end and connecting their respective ball sockets. Mso leading from the chamber I28 is a passage I38 leading through the abutment 12 to the spherical end surface of Cardan shaft 66. The latter is provided with a central longitudinal passage I40 extendingfrom end to end and registering with a central passage I42 in the abutment 14. 'The shaft I6 is provided with a radial passage I 44 extending from the right-hand end of bore 18 to the chamber 25 between seals 22 and 24. A small spring loaded ball valve I46 is provided opening out of the chamber between the seals and maintaining a predetermined pressure therein. The exit from the valve I46 opens into the housing I0.

'I'h'e compressor displacement is controlled by piston 90, and, for simplicity, this may be made responsive directly to the suction pressure by connecting the left end of cylinder 92, in Figure 1, to atmosphere and connecting the right end thereof to the compressor casing by the provision of "a passage I52 in the rod 88. In this case a large spring I54 is used to bias the yoke downwardly in Figure 1. Preferably, however, the piston 90 is operated by oil under pressure controlled by a valve responsive either to suction pressure or to temperature.

Such a valve is illustrated at the lower righthand portion of Figures 1 and 2 and designated I10. It may take the form of a conventional four-way reverse valve for directing pressure oil from chamber 25 delivered through passage I68, selectively either to the left end of cylinder 92 through passage I12 or to the right end through passage I14. The stem of valve I10 is operated by a bellows I16 at its right-hand end, sealed to the wall of housing I0 which is thus responsive to suction pressure. A spring I 18 normally biases the valve stem to the right. Provision for adjustment of spring I18 is made by means of the threaded stem of valve I10 which may be adjusted in and out relative to the end wall of the bellows I16. A look nut I seals the threaded stem when tightened in place.

Referring now to Figure 6, there is shown diagrammatically a, refrigerating circuit incorporating the compressor. The refrigerant feed line I56 runs from pintle I22 through a condenser I58, receiver I60, and expansion Valve I62. The evaporator I64 is connected to the expansion valve and its outlet connects by suction line I66 to the housing I0.

In operation with shaft I6 being driven and with the system filled with refrigerant and with a quantity of oil partially filling the housing II), with the parts in position shown in Figure 1,

the displacement of the compressor is zero, andthe shaft I6 and the cylinder barrel 46 are rotated without causing the pistons 32 to partake of any reciprocatory movement in the cylinders 48. In response to a demand for refrigeration, the control valve I10 will shift to admit oil to the right end of cylinder 92 exhausting oil from the left end and forcing piston to the left to swing the yoke 34 counter-clockwise on a trunnion 31.

It will be understood that in the preferred construction using valve I10 that the spring I54 is omitted and the passage I52 is blocked. This inclines the axis of cylinder barrel 46 with respect to the'axis of shaft I6 causing pistons 32 to partake of an in and out movement as they revolve about the cylinder barrel axis. Thus, as each piston passes the inlet port I06 it will be withdrawing away from the valve plate 40, thus drawing in a mixture of'refrigerant and oil into its corresponding cylinder. As the piston passes across top dead center of Figure l, the end of the cylinder 48 cuts off from inlet port I00 and opens up to discharge port I02, and while in contact with the same, the piston will move toward the valve plate discharging the contents of the cylinder into discharge port I02.

The mixed oil and refrigerant are separated in the bore I06, the gaseous refrigerant passing through the uptake pipe 2 passage H4, pintle H6 and through the telescoping delivery connection to the compressor discharge port I 22. The volumetric displacement of the compressor per revolution will be determined by the angle of inclination of the cylinder barrel axis to the shaft axis and can be varied to suit requirements by operation of the control valve I10 and control piston 80. Thus, the compressor will deliver refrigerant at any rate required to meet both varying refrigerant demands and also to compensate for variations in speed at which the shaft I6 is driven. The oil which is separated in the oil separating chamber I06 is under refrigerant disehargepressure and is conducted through. the

passage l24lto the chamber 62* where it acts upon right face of'piston 58; the area of piston 58is chosen with respect to the area of the valve plate surface 44 asto almost entirely compensate for the pressure acting on the end surface of cylinder barrel 46 tending to separate it from the valvev plate 40. Preferably, the area of piston 58 may be-so chosen as toovercompensate and thus create aslight increased hold down force as the discharge pressure rises.

"From the bore 62-, oil is delivered thru the-passage. l2-6 to the chamber I28 where it is availae life fordistribution under pressure through the radial passages i3!) to the ball and socket joints of connecting. rods 3i}, escaping finally through the clearance between theball and socket 28. Another portion of the oil delivered to chamber l2&: passes through the passages I38, I40 and M2 lubricating the universal joint pivots and finding its way ultimately through the passage M4 to the chamber 25. It will be noted that the area of the spherical retainers l2 and 14 are preferably equal, thus eliminating any tendency for oil pres- Sure to shift the Cardan shaft endwise, its position being maintained by the spring 80 and the shoulder 82. The oil in the chamber lubricates bearingiii and finally passes to the interior of the housing it through the relief valve I46. The latter preferably has a setting slightly below the minimum" discharge pressure for which the compressor designed so that there will be a. continualgflow through the path as previously de- Sm'ibed'. The oil, finding its Way back to the inte ior of housing It, will again be entrained in the refrigerant taken in through intake passage 04: and thus start upon another cycle of oil circulation.

It, will be noted that the telescoping delivery connection has a larger area than necessary for delivery purposes and this is provided for the purpose of balancing the fluid pressure forces acting upon the yoke 34. It will be seen that the thrust of the fluid in those cylinders which are in contact with the discharge port 12 are acting on the yoke 36 at a distance from the trunnion 31, thereby creating a couple tending to swing the yoke 34 counterclockwise. The area of the telescoping discharge connection is preferably so chosen with regard to its lever arm on the yoke as to exactly counter balance the piston thrust acting on the yoke, thus leaving the yoke free to take up any position dictated by the control piston 90.

It will also be noted that the construction described provides for a minimum clearance volume and that this clearance volume is independent of the position of yoke 34. By pivoting the yoke 34 on an axis tangent to the circle on which the connecting rod socket centers are located on the driving flange, it will be seen that each piston, as it passes'the bottom dead center position in Figure 1, will be closely adjacent to the valve plate regardless of the position of yoke 34. That is because the center of the socket 28 at that moment is coincident with the pivotal axis of yoke 34 and thus swinging of the yoke cannot cause any inward or outward movement of a piston while it is in this position.

The present invention thus provides a variable displacement compressor eminently suited for refrigeration service, either for constant speed drive, as from an electric motor prime mover, or for variable speed drive, directly from a railway car axle or from a. motor vehicle engine, for x ample.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood. that other forms might be adopted, all coming within the. scope of the claims which follow.

What is claimed is asfollows:

1-. A variable stroke compressor comprising in. cembination, a housing, a drive shaft journalled iri-thehousing and having a plurality of sockets arranged in a circle about one side thereof a. yoke pivotally mounted on: the housing, to swing about an axis tangentto the socket circle and including adistributing valve surface having an inlet port. and an outlet port, a. cylinder barrel rotatably mounted on the yoke and having a plurality of axial-cylinders therein, distributing ports inv the cylinder barrel cooperating with the ports inthe distributing valve surface, universal joint mecha-- nism connected between the drive shaft and the: cylinder barrel, a plurality of pistons slidably mounted in the cylinders, connecting rods. articulated tn the pistons and to the sockets on the driving flange, and means for substantially counteracting the net. thrust on. the yoke produced bvfi-uidpressure within the cylinders, said means. including a telescoping piston and cylinder assembly connected between the yoke and the house ing and forming a fluid delivery conduit between the swingable yoke and a fixed point on the housmg.

2. A variable stroke-compressor comprising in combination, a housing, a. drive shaft journalled in the housing and-having a plurality of sockets. arranged in a circle about one side thereof, a yoke. pivotally mounted on the housing to swing about an axis tangent to the socket circle and including a distributing valve surface having an inlet port and an outlet port, a cylinder barrel rotatably mounted on the yoke and having a plurality of axial cylinders therein, distributing ports in the cylinder barrel cooperating with the ports in the distributing valve surface, universal joint mechanism connected between the drive shaft and the cylinder barrel, a plurality of pistons slidably mounted in the cylinders, connecting rods articulated to the pistons and to the sockets on the driving flange, an inlet connection leading to the interior of the honsing, a delivery connection from the outlet port in the yoke to the exterior of the housing, an oil separator in communication with said delivery connection and having an oil delivery passage subject to outlet pressure, and passages leading from the oil delivery passage to said pistons and articulated connecting rods.

3. A variable stroke compressor comprising in combination, a housing, a drive shaft journalled in the housing and having a plurality of sockets arranged ni a circle about one side thereof, a yoke pivotally mounted on the housing to swing about an axis tangent to the socket circle and including a distributing valve surface having an inlet port and an outlet port, a cylinder barrel rotatably mounted on the yoke and having a plurality of axial cylinders therein, distributing ports in the cylinder barrel cooperating with the ports in the distributing valve surface, universal joint mechanism connected between the drive shaft and the cylinder barrel, a plurality of pistons slidably mounted in the cylinders, connecting rods articulated to the pistons and to the sockets on the driving flange, an inlet connection leading to the interior of the housing, a delivery connection from the outlet port in the yoke to the exterior l of the housing, an oil separator in communication with said delivery connection and having an oil delivery passage subject to outlet pressure, and passages leading from the oil delivery passage to the universal joint mechanism.

4; A variable stroke compressor comprising in combination, a housing, a drive shaft journalled in the housing and having a plurality of sockets arranged in a circle about one side thereof, a yoke pivotally mounted on the housing to swing about an axis tangent to the socket circle and including aidistributing valve surface having an inlet port and an outlet port, a cylinder barrel rotatably mounted on the yoke and having a plurality of axial cylinders therein, distributing ports in the cylinder barrel cooperating with the ports in the distributing valve surface, universal joint mechanism connected between the drive shaft and the cylinder barrel, a plurality of pistons slidably mounted in the cylinders, connecting rods articulated to the pistons and to the sockets on the driving flange, said housing being subject to the suction pressure of the compressor, an oil pressure chamber surrounding the drive shaft, oil separating means associated with the outlet port, a passage connecting the oil separator to said oil pressure chamber, and a pair of shaft seals on either side of the oil pressure chamber, one sealing oil leakage from the oil chamber to the exterior of the housing and the other sealing oil leakage from the oil chamber to the interior of the housing.

5. A variable stroke compressor comprising in combination, a housing, a drive shaft journalled in the housing and having a plurality of sockets arranged in a circle about one side thereof, a yoke pivotally mounted on the housing to swing about an axis tangent to the socket circle and including a distributing valve surface having an inlet port and an outlet port, a cylinder barrel rotatably mounted on the yoke and having a plurality of axial cylinders therein, distributing ports in the cylinder barrel cooperating with the ports in the distributing valve surface, universal joint mechanism connected between the drive shaft and the cylinder barrel, a plurality of pistons slidably mounted in the cylinders, connecting rods articulated to the pistons and to the sockets on the driving flange, said housing being subject to the suction pressure of the compressor, an oil pressure chamber surrounding the drive shaft, 011 separating means associated with the outlet port, a passage connecting the oil separator to said oil pressure chamber, a pair of shaft seals on either side of the oil pressure chamber, one sealing oil leakage from the oil chamber to the exterior of the housing and the other sealing oil leakage from the oil chamber to the interior of the housing, and a relief valve opening from the oil chamber to the interior of the housing.

RALPH L. TWEEDALE.

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

UNITED STATES PATENTS Number Name Date 978,668 Slick Dec. 13, 1910 1,506,892 Egersdorfer Sept. 2, 1924 2,146,117 Gros Feb. 7, 1939 2,168,658 Thomas Aug. 8, 1939 2,234,469 Dick Mar. 11, 1941 2,277,570 Vickers et al Mar. 24, 1942 2,284,109 Vickers May 26, 1942 2,284,146 Herman May 26, 1942 2,284,169 Robinson May 26, 1942 2,288,768 Zimmerman July 7, 1942 2,290,764 Neuland July 21, 1942 2,298,850 Vickers Oct. 13, 1942 2,353,745 Molly July 18, 1944 2,353,917 Molly July 18, 1944 2,382,437 Molly Aug. 14, 1945

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