US 2209090 A
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Description (OCR text may contain errors)
July 23, l940- J. PIERoTTl Er A1.
' REFRIGERANT COMPRESSOR Filed July 27. 1937 3 Sheets-Sheet l lm Y my 253, w40. .1. PIERO, ET AL f www@ REFRIGERANT COMPRES S 0R Filed July 27, 1957 sfshets-sheet 2 INVENTIORS /05e/0/w /P/'e/"o/ BY 0550/'l C job/750m ATTORNEY.
July 23, 1940. J. PlERoT'n Er AL REFRIGERANT COMPRESSOR Filed July 27, 1937 :s sheets-sheet s wb. n. WO m on n MWh A hc 0. w M 0. Off@ 9 n i Patented July 23, 1940 PATENT' "orgie" aaraiGEnAN'r eoivlumasson Joseph Pierotti, Dalsland, and Oscar C. Johnson, Piedmont, Calif.; said Johnson assignor to said Pierotti Application July-'2.7, 1937, Serial No. 155,910 c claims. (ci. 23o-52) The invention relates to air cooling andrefrigeratlng systems and particularly of the type adapted for use in automotive vehicles and of the type disclosed in the co-pending application of 5 l JosephiPierotti, Serial Number 97,937, filed August 26, 1936, now abandoned.
In the refrigerating system disclosed in the application aforesaid, the source of power for the refrigerant compressor is in the form of a vacuum l0 motor whichlis adapted for connection to the intake manifold of an internal combustion engine for energizing by the source of low pressure thereat. Also in the refrigerating system disclosed in said application the refrigerant com- 15.. pressor is unitarily associated with the vacuum motor. Such an organization provides two outstanding advantages. One lies inthe utilization of the large quantity of air at a reduced tempera- E ture in thevacuum motor for absorbing heat from the compressed refrigerant in the compressor and thereby reducing the amount of heat which must be dissipated in the cooler unit of the refrigerating system. Secondly, the use of avacuum motor 'and the simple connection thereof with the engine by means of a conduit makes possible the positioning of the refrigerating unit substantially in any position in the body of the automotive vehicle and completely eliminates the relatively complicated drive mechanism heretov fore required with other types of refrigerating systems in automotive Vehicles. The present nvention provides for substantial improvements in various features of the refrigerating system of the character described in affording improved fluid separation between the vacuum motor and the refrigerant compressor and an improved valve construction in the refrigerant compressor itself. Another object of the present invention is to provide a further utilizationof the air drawn into the vacuum motor for cooling the compressed refrigerant by causing such air to pass in thermal contact with the cooler unit of the -refrigerating system.`
'I'he invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form vof the invention which I lvduring reciprocation of the pistons and shaft.
is illustrated in the drawings accompanying and forming part of the specication. It is to be understood, however, that variations in the showing made by the said drawings and description may be' adopted within the scope of `.the invention as set forth in the claims.
Referring to said drawings:
Figure 1 is a vertical sectional view of the motor and compressor unit forming part of the present refrigerati/ng system. l
Figure 2 is an enlarged cross sectional view of one of the compressor pistons. l
Figure 3 is an enlarged cross sectional View of 5 one of the packing glands ,of the compressor unit.
Figure 4 is aplane view of the motor and comprcssor'unit with part of the top cover removed.
Figure 5 is an end view of the motor' and compressor unit. y 10 Figure 6 is adiagrammatic Yrepresentation of the refrigerating system.
The refrigerating system of the present invention and as illustrated in the accompanying drawings, see Figure 6,'comprises a compressor and 15 vacuum motor unit 6 and a refrigerant circuit including a refrigerant cooler 1, a refrigerant reservoir 8, an expansion valve 9, and refrigerating coils I I, the different parts of the system being connected by the following conduits: con- 20 duits I2 conduct the compressed refrigerant from the compressor to conduit I2 leading to the cooler 1, conduit I4 connects the cooler 1 with the reservoir 8, conduit I6 connects the reservoir with the expansion valve 9, conduit I1 connects the expan- 25 sion valve with the refrigerating coils II, and conduit I8 connects the refrigerating coils with intake conduits I9 of the compressor.
VThe motor and compressor unit 6 is embodied inthe unitary casing 2l having a centrally dis- 30 posed vacuum motor Acylinder 22 and aligned and connected cylinders 23 and 24 axially extending from the opposite ends'26 and 21 of the cylinder 22, the cylinders 23 and 24 here being of a Vreduced diameter from the vacuum motor cylinder 35 22 so as to enable the production of a greater pressure therein. Mounted for reciprocation in the cylinder 22 is a piston Zaland connected on a common shaft 29 therewith in each of the cylinders 23 and 24` are pistons 3| and 32 which recip- 40 rocate with andV are driven by the piston 28 through the'medium of .the shaft 29.
In order to avoid wear on the pistons due to any slight misalignment of the cylinder axes, we prefer to connect the piston 28 to the shaft 45 with a 'radial slip joint to permit radial movement of the shaft relative to the piston 28 This is shown by mounting the piston on a spool-like member 96 consisting of a central 50 cylindrical body 91 which is fastened to the shaft by means of a set screw 98 and fastening to the opposite longitudinally spaced radial sides of the body a pair of discs 99 which arevsomewhat larger in diameter than the body 91 to provide an an- 55 |02 between which arel clamped a pair `of sheets |03 and |04 of packing material, and the outer ysides |06 and |01 of the sections are provided with annular recesses `|08 and |99 to permit mounting of a central opening through'the sections about the body portion 91 ofthe spool with the discs 99 extending intoA the recesses |08 and |09. VThe diameter. of the opening |l|| and of the recesses |08 and |09 are somewhat larger than the diameters of'the member 91 and the discs 99 so as to permit of a radial movement of the piston relative to the spool member.
lReciprocation of the piston l28 is effected as hereinbefore indicated by a source of reduced pressure which is preferably obtained from the intake manifold 33 ofthe internal combustion engine 34 of the vehicle although as will be understood other sources of'reduced air pressure such as a pump may be used. Such source of reduced pressure and atmospheric pressure are communicated with the cylinder 22 at Opposite sides of the piston- 28 to produce a pressure differential for displacing the piston. The atmospheric and vacuum connections to the lunit are made by-way of conduits 36 and 31 connected to their respective sources and to a valve casing 38 provided on the unit andwhich is operative to alternately connect the vacuum and atmospheric pressures at opposite ends of the cylinder to cause a reciprocation of the piston 28. Any suitable valve mechanism appropriately timed in its operation to the movement of the piston 218 may be used. As here shown a sliding inverted cage 'connecting one of said passages to said vacuum passage leaving the other passage open to the atmosphere in the valve casing communicated thereto by the conduit 36. Operation of the slide valve 39 is here eifeoted by a toggle mechanism 44 actuated by sliding arms 46 and 41 having portions 48 and 49 extended into the cylinder 22 through the opposite ends 26 and 21 thereof and engaged and displaced by the piston 28 upon movement thereof to the opposite ends of its stroke.
I'he operation of the motor unit n the manner described causes the passage of a relatively large quantity of air from the atmosphere through the valve mechanism and into the motor cylinder and then into the intake manifold of the engine. As will be understood, the air is subject to a substantial drop in pressure in the vacuum motor unit which cools the air and which, coupled with the relatively large volume of air drawn through the motor unit in thermal contactwith the casing 2|, enables a material absorption of heat by the air from the refrigerant cylinders 23 and 24. Also the operation of the unit fromv the source of vacuum at the intake manifold of the engine enables the necessary power for the plant to be communicated through a simple conduit 50 whereby lthe customary use of the drive means, pulleys, gears, and shafts, and the like heretofore associated 'with an automotive refrigerating system, is entirely avoided. Then, too, since the conduit 50 may be as long and flexible as desired, the motor. compressor unit 6 may be positioned at substantially any desired portion of the vehicle without regard to the availability of a driving lconnection with the vehicle motor as has been heretofore necessary.
As an important'feature of the present invention we provide an improved packing means 6| at the opposite ends 26 and- 21 of the cylinder 22 for separating the air in this chamber from the refrigerant in the cylinders 23 and 24. As here illustrated, this packing means comprises a ring member 52 having. a central opening 53 surrounding the shaft 29 and threaded into a socket 54 in the end walls 26 and 21 of the cylinder 22 against an inner shoulder or side 56 of the socket.
The member is formed over its outerside 61 with an annular recess 58 extending from ad jacent the outer peripheral portion 59 to the opening 53 and is beveled adjacent the opening towards the opposite side 6| of the member.
Mounted in the recess 50 is a disc l62 of fiexible,
29 by means of a backing or supporting plate 63n which is also mounted on the shaft and tted into the recess 58 and is widened or ared adjacent a lcentral opening 64 therein and' at the opposite sides 66 and 61 in substantial conformity with the bevel of the recess so as to hold the disc 62 snugly fitted against the shaft 29 and in a substantially parallel relation therewith at the contact of the disc with the shaft. A second disc 68 of a flexible, oil resistant material is mounted against the opposite sidey 61 of the supporting plate 63 and is held thereagainst and also against the shaft 29 by means of asecond ring member 69 which is formed complementary to the member 52 and is threaded into the casing socket 54 with the recess 1| therein iitted over the disc 68 and a part of Ithe periphery of the plate 63 and with the peripheral portion 12 thereof abutting the' complementary peripheral portion 59 of the member .52. If desired, wrench openings 13 and 14 may be provided in the exposed sides of the ring members for threading the latter into and out of lthe sockets 54. An important feature of the packing means is the provision for supporting the flexible discs 62 and 68 with the central portions of such discs pressed firmly against the shaft and extending into substantially parallel relation with the shaft' so as to insure the sealing of the motor and compressor cylinders'from each other without undue friction on the shaft 29.
Each of the compressor units 23 and 24 is provided with refrigerant intake and discharge passages l2 and i9 respectively adjacent the outer and inner ends of the cylinders 'and check valves 16 and 1i are provided at the joinder of' the conduits |2 and |3 for limiting the-passage of refrigerant through the discharge line in a direction away from the outer ends of the cylinders and at the joinder of the conduits i6 and I9 for restricting the refrigerant floul` through such conduits to a direction to the inner ends of the cylinders. Thus on movement of one of the pistons 3| or 32 in its respective cylinder towards the outer end thereof, refrigerant is compressed between the head 18 of the piston and the outer end 19 of the cylinders while refrigerant is drawn into the inner end of the cylinder by the piston and the packing means 5|. movement both of the valves 16 and 11 are open. On the return movement of the piston both of the valves 16 and 11 close due to the reversal of pressure and vpassage of the refrigerant to the In the course of such outer end ofthe cylinder is afforded through These openings are covered by a exible diaphragm 82 which is held by a retaining washer 83 secured to the piston bya screw 84 and is energized by the pressure differential at the oppo 4 site sides of the piston to cover and uncover the openings 8l. Preferably the diaphragm 82 is in the form of a thin metal disc of conical form so' as to normally 'cause the latter to lie in spacedrelation-from the openings-8|. However on movement of the piston towards the outer end 1l of the cylinder and the building up of pressure' at the head of the cylinder the diaphragm 8 2 will snap into a position against the surface and seal off the openings 0I to thereby afford a compression of the refrigerant fluid contained between the piston and the outer end of the cylinder. Preferably each of the pistonsv is provided with a plurality of piston'rings 81 for sealing the piston in the'cylinder.
As another important feature of the present invention the air drawn into the vacuum motor during the operation of the unit is caused to pass in thermal contact over the cooler I so as to absorb heat from the compressed refrigerant therein. As here shown the cooler is in the form of a plurality of coils 88 which are wound in a sinuous manner and provided with radiating ins Y 89 and enclosed within a casing 9|, the coil and casing assembly being mounted directly over the refrigerant reservoir 8 and the lower end of the casing being open so as toA draw the air first over the reservoir casing and then through -the casing in heat transfer relation with the coils and fins. The air is withdrawn from the top of the casing by means of the atmospheric air intake conduit 36 of the vacuum motor.
1. In a refrigerating system of the character thereof, packing means surrounding said shaft and separating said cylinders and comprising, a ring surrounding said shaft and supported by said vcasing and provided with an annular recess extending to said shaft, a disc of flexible material mounted over said shaft and in said recess, a supporting plate surrounding said shaft and extending into said recess to hold said disc therein, a second disc of flexible material surrounding said shaft and mounted against said plate, and a second ring member surrounding said shaft and supported by said casing in abutting relation against said last named disc, means for alternately connecting the opposite ends of oneof said cylinders with a source of reduced pressure and the atmosphere respectively to produce an oscillation of said pistons, and means for charging and discharging said other cylinder with a refrigerant fluid.
2.In a refrigerating system of the character described an integral motor and compression unit comprising, a casing providing a plurality of aligned and 'connected cylinders, pistons mounted for reciprocation in said cylinders, a shaft connected to said pistons for simultaneous movement thereof, packing means surrounding said shaft and separating said cylinders and comprising, a ring having a central opening surrounding said shaft and threaded in said casing between said cylinders and being provided on one side thereof with an annular recess extending from adjacent the outer periphery thereof to said opening and being beveled adjacent said opening towards the opposite side of said member, a disc of exible material mounted in said recess and extendinginto said opening in surrounding and sealing relation to said shaft and in substantially parallel relation to said shaft, a backing plate having a. central opening mounted over sad shaft and fitted into said recess against said disc and being flared outwardly adjacent said opening on theopposite sides thereof in -conformity with the beveled recess portion, a disc of flexible material having a central opening mounted over said shaft and against the opposite side of said plate, and a second ring member provided with a centralsaid other cylinder with a refrigerant fluid.
3. hIn a refrigerating system of the character described, a refrigerant compressor comprising, a casing providing a cylinder and having refrigerant inlet and discharge passages adjacent the opposite ends Yof said cylinder, a piston reciprocally mounted in said cylinder, a check valve in said discharge passage limiting the refrigerant flow therein to a direction away from said cylinder, a check valve in said inlet passage limiting the refrigerant flow therethrough in a direction to said cylinder, said piston being provided with passage means through'the head thereof for connecting said cylinder at opposite sides of said piston, and a pressure responsive valve mounted 1lil in said passage means and flat conical diaphragm of lthin resilient material fastened. at its center to said piston generally across said passage means and being operative when subjected to opposite pressure differentials caused by movement of said piston towards and away from said discharge passage to spring to positions closing and opening said passage means respectively.
4. In a refrigerating system of the character described, a'refrigerant compressor comprising, a casing provided with a cylinder having inlet and discharge passages opening through adjacent the opposite ends of the cylinder, check valves mounted in said passages for restricting the flow therein to and from said cylinder respectively, a
piston reciprocally mounted in said cylinder and having a flat conical head portion and an opening through said head portion for communicating the cylinder portions at opposite sides ofsaid piston, a rigid disc fastened to the center of the Ahead of said piston, a at conical diaphragm mounted between said disc and piston head and covering said opening and being responsive to the pressure differential at the opposite'sides of said piston to close s aid opening upon movement of said piston in the direction of said discharge passage and to move against said disc to uncover said opening upon movement of 4said piston in the direction of said inlet passage.
5. In a refrigerating system of the character described, an integral motor and compressor unit comprising, a casing providing a central cylinder and aligned side' cylinders .connected therewith, pistons mounted for reciprocation in said cylinders, a shaft connected to said pistons for simultaneous movement thereof, slip connection means between said shaft and piston in said cen- L.refrigerant fluid into said cylinder for-.compression and discharge.
v6. InI a refrigeratingsystem of the character described, an integralmotor and compressor unit comprising, a casing providinga central cylinder and'aligned side cylinders connected therewith. pistons mounted for recip: ocation in said side cylinders, a shaft connecter. to said pistons for siv multaneous4 movement thereof, packing means surrounding said shaft at opposite ends oi' said central cylinder and separating the latter from said side cylinders, a piston in said central cylinder adapted to move said shaft, means on said shaft including members extending' radially from saidv shaft to opposite sides of said central cylinvder piston to transmit power from said piston to said shaft, said central cylinder piston having l sliding engagement with said means whereby small motion of said central cylinder piston is a1- lowed transversely with respect. to said shaft, valvey means for alternately connecting the opposite ends of the central cylinder 4to a source of reduced pressureand the atmosphere respectively Ato produce yan oscillation of the piston therein andof. said side pistons, and valve'means for entering a refrigerantfluid into said cylinders for compression and discharge. l
JOSEPH PIERO'III. OSCAR C. JOHNSON.