US3111820A

US3111820A - Rotary compressor injection cooling arrangement

Info

Publication number: US3111820A
Application number: US150579A
Authority: US
Inventors: Leonard W Atchison
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1961-11-06
Filing date: 1961-11-06
Publication date: 1963-11-26
Anticipated expiration: 1980-11-26

Description

Nov. 26, 1963 L. w. ATCHISON ROTARY COMPRESSOR INJECTION COOLING ARRANGEMENT.

Filed Nov. 6, 1961 3 Sheets-Sheet 1 F'IG.I

. INVENTOR. LEONARD W. ATCH \SON Y E N m w A w H Nov. 26, 1963 L. w. ATCHISON 3,111,820

ROTARY COMPRESSOR INJECTION COOLING ARRANGEMENT Filed Nov. 6, 1961 3 Sheets-Sheet 2 F'IG.3

LEONARD W. ATC H [SON BY /A( HIS ATTORNEY Nov. 26, 1963 w. ATCHISON ROTARY COMPRESSOR INJECTION COOLING ARRANGEMENT :5 Sheets-Sheet 3 Filed Nov. 6, 1961 F'IG.6

INVENTOR. LEONARD VV- ATCHlsON ZQW W HIS ATTORNEY F'IG.7

United States Patent 3,111,820 ROTARY COMPRESSOR INJECTION COOLING ARRANGEMENT Leonard W. Atchison, Louisville, Ky., assignor to General Electric Company, a corporation of New York Filed Nov. 6, 1961, Ser. No. 150,579 5 Cla'nns. (Cl. 62--505) The present invention relates to rotary compressors and more particularly to an arrangement for supplying condensed liquid refrigerant to the compression chamber of the rotary compressor for cooling the gases during the compression thereof.

It is common practice in the field of refrigeration to mount both the refrigeration compressor and its drive motor within a hermetically sealed casing. In such an arrangement it is necessary to provide some means for cooling the drive motor in order to maintain its temperature within practical operating limits. One means employed for this purpose is to pass the high pressure discharge gas from the compressor unit over the compressor motor after the high pressure gas has been cooled to a low enough temperature to remove heat from the motor as it passes thereover. The heat removed from the motor is then carried by the high pressure discharge gas and dissipated in the condenser of the refrigeration system. This is an efficient method for maintaining the motor at a proper operating temperature but requires that the high pressure discharge gas be pre-cooled before it is passed into intimate contact with the motor.

One means for cooling the high pressure gas before it is passed over the motor is to mix a small amount of liquid refrigerant with it to cool the gas through evaporation of the liquid refrigerant. The liquid refrigerant flashes into gaseous form and mixes with the discharge gas thereby cooling it snflic-iently to remove heat from the motor. The liquid refrigerant must be delivered to the high pressure gas issuing from the compressor from some point in the refrigeration system such as from the liquid portions of the condenser. Therefore, some means must be provided for reducing the pressure at the outlet of the liquid supply line in order to obtain flow of liquid refrigerant from the condenser, or other portions of the system, which are normally at slightly lower pressure than the high pressure gas discharging from the compressor.

One arrangement for accomplishing injection of liquid refrigerant into the high pressure gas is disclosed in the invention of the commonly assigned application of Dean C. Rinehart, S.N. 139,447. The present invention is an improvement over the invention of the said Dean C. Rinehart, which was made prior to the present invention, and nothing is herein claimed as my invention that is shown and described in the Rinehart application, which is to be regarded as prior art with respect to this present application.

In the aforementioned Rinehart application, the pressure drop in the refrigerant line from the hermetic case to the source of condensed refrigerant in the condenser of the system is overcome by injecting liquid into the compression chamber of a rotary compressor through an injection port that is opened and closed by the end of the compressor rotor at such times when the pressure of the gas in the chamber is lower than the pressure in the condenser or source of liquid refrigerant.

It is an object of the present invention to provide an improved arrangement for injecting liquid refrigerant into semi-compressed gas within the compression chamber of a rotary compressor prior to discharge of the gas mixture from the chamber.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the inven- 3,111,820 Patented Nov. 26, 1963 tion will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In carrying out the objects of the present invention, there is provided a rotary compressor unit adapted for use in a refrigeration system including a condenser for condensing refrigerant from the compressor and an evaporator for evaporating the condensed refrigerant. The compressor unit and its drive motor are mounted within a hermetically sealed case into which the compressor unit discharges its compressed refrigerant which then flows over the motor prior to passing into the other portions of the refrigeration system. The compressor unit includes a cylinder having an annular compression chamber encompassing a rotor which is driven in eccentric motion around the chamber so that the peripheral surface of the rotor moves progressively into sealing relation with successive portions of the annular chamber to drive refrigerant around the chamber. A blade or vane is reciprocally mounted in the housing of the compressor and is biased against the peripheral surface of the rotor thereby dividing the chamber into high and low pressure sides during rotation of the rotor. Low pressure gas is delivered through means of a suction gas inlet to the low pressure side of the chamber and compressed during the eccentric rotation of the rotor around the chamber. High pressure gas is then discharged through an outlet passage leading into the hermetic casing where it flows over the motor. Means are provided for delivering liquid refrigerant into the compression chamber to cool the gas being compressed therein including a refrigerant injection passage in the vane having an opening adapted to communicate with the high pressure side of the chamber when the vane moves into the chamber during reciprocation of the vane as the rotor moves around the chamber thereby injecting a small amount of liquid refrigerant into the chamber during each cycle of the rotor.

For a better understanding of the invention, reference may be had to the accompanying drawings in which:

FIGURE 1 is a side elevational view partially in cross section of a hermetic refrigeration compressor incorporating the present invention;

FIGURE 2. is a partial plan view taken along line 2-2 of FIGURE 1;

FIGURE 3 is a schematic view of a refrigeration system including the compressor of the present invention;

FIGURE 4 is a schematic view illustrating certain angular positions of the rotor and the related positions of the vane during each cycle of the rotor;

FIGURE 5 is a cross-sectional view taken along line 55 of FIGURE 2, illustrating the position of the injection port with respect to the compression chamber and the reciprocable vane;

FIGURE 6 is an enlarged perspective view of another embodiment of the invention showing the vane in its extended position to illustrate the manner in which the injection passage is exposed to the compression chamber; and

FIGURE 7 is a partial plan view further illustrating the same embodiment as shown in FIGURE 6.

Referring to FIGURE 1, there is shown a hermetic compressor 1 including a hermetic casing 2 in which there is disposed a refrigerant compressor unit 3 having an annular chamber or compression chamber 4 defined within a cylinder or housing 5. Disposed for rotation within the chamber 4 is a rotor 6 which is driven by an eccentric 7, formed as an integral part of the drive shaft 8, extending downwardly from the motor 9. A bearing 11, formed in the supporting main frame 12, supports the shaft 8 above the eccentric 7 for rotation by the motor. It should be noted that the upper end wall enclosing the annular chamber 4 is provided by the main frame 12. The main frame 12 also supports the compressor unit 3 within the hermetic casing. The opposite or lower end wall of the compressor chamber 4 is formed by a bearing plate which also supports the lower end of the shaft 8 in a bearing 10a.

As may best be seen in FIGURE 2, the cylinder 5 is provided with a radial slot 13 having slidably disposed therein a blade or vane 14 which is biased into engagement with the peripheral surface 6a of the rotor 6 thereby dividing the chamber 4 into low and high pressure sides respectively designated 4a and 4b. In the illustrated embodiment of the invention, the end of the blade 14 is biased against the periphery of the rotor by means of a spring 16 arranged Within an enlarged opening 13a forming the rear part of the radial slot 13. During operation of the unit, the rotor 6 is eccentrically rotated within the chamber by the eccentric 7 so that the peripheral surface 6a of the rotor moves progressively into sealing relation with successive portions of the annular chamber thereby forcing gas ahead of it in the direction of rotation, as is Well known in the art.

As may be seen in FIGURE 3, the hermetic compressor 1 is adapted to be connected into a refrigeration system to receive suction gas from an evaporator through a suction line 20. Means are provided for delivering the suction gas into the low pressure side 4a of the annular chamber 4 from the suction line 20. More specifically, referring to FIGURE 2, these means include a suction port 17 formed in the cylinder 5 and communicating with the 'annular chamber 4. The suction port 17 delivers low pressure gas into the low pressure side 4a of the compression chamber 4 where it is compressed between the peripheral surface of the rotor 6, the sides of the annular chamber, and the high pressure side 14a of the vane 14 during rotation of the rotor 6 around the chamber.

Means including a discharge port 18 and discharge chamber 19, are provided for directing the high pressure gas from the high pressure side 4b of the annular chamher 4 into the hermetic casing 2. Mounted within the discharge chamber 19 is a suitable valve 21 for assuring proper compression of the gas issuing through the discharge port 18 and for preventing reverse flow of gas back into the compression chamber 4. As may be seen in FIGURE 1, the high pressure gas from the discharge chamber 19 flows into the hermetic casing 2 through a passage formed in the main frame 12, or formed in the upper end wall of the compressor unit. After flowing upwardly over the motor 9, the high pressure gas is conducted out of the hermetic casing 2 through a suitable discharge means or outlet in the upper end of the case. The gas then flows through the discharge line (shown only in FIGURE 3) into the condenser 22 where the heat absorbed by the refrigerant in the other portions of the system is extracted. As the gas in the condenser 22 is cooled, it condenses so that the refrigerant in the latter stage of the condenser is, therefore, largely in liquid form. A suitable expansion means is provided between the condenser and the evaporator for expanding liquid refrigerant from condenser pressure to evaporator pressure during operation of the system. In the illustrated embodiment of the invention, the expansion means comprise a capillary 23 located between the condenser 15 and evaporator 22 of the system.

Referring again to FIGURE 1, there is shown an arrangement whereby lubricating oil is provided for the various bearing surfaces and other moving parts of the unit. As may be seen in FIGURE 1, lubricant from a reservoir or body of oil 24 in the lower portion of the hermetic casing is pumped by centrifugal force up the inner surface of an axial cavity 26 in the shaft to the various bearings of the compressor.

A compressor of the above-described type, when tested in an air conditioning unit in'which air at approximately 80 F. was circulated over the evaporator and air at approximately 95 F. was circulated over the condenser, produced a refrigerant gas pressure Within the hermetic case of approximately 300 p.s.i.g. The pressure within the high pressure side 4b of the annular chamber reached the maximum of 330 p.s.i.g. The suction pressure in a refrigeration system of this type normally runs approximately 225 p.s.i.g. less than the discharge pressure, or about 75 p.s.i.g., and the temperature of the suction gas is approximately 60 to 70 F. Of course, the various applications of the above compressor and the particular design features of the refrigeration system all effect the pressure of the gas within the case, but as can be seen from the above-representative figures, pressure within the hermetic case 2 is substantially above that of suction pressure. As the suction gas is compressed within the chamber from 75 p.s.i.g. to 330 p.s.i.g., there is a substantial increase in temperature of this gas during compression. In the tested refrigeration system, for example, the gas temperature at the discharge outlet 18 was approximately 250 F. when there was no cooling of the gas during the compression cycle. Under most conditions of operation this gas temperature would be so great that it could not dissipate suflicient motor heat to assure proper motor operating temperatures. If the gas is permitted to continually discharge at any temperature above 200 F., there is likely to be insufficient cooling of the motor and damage to the motor insulation or windings is likely to occur.

In order to assure that the temperature of the discharge gas is sufficiently low to properly cool the motor as the gas is circulated thereover, the present invention provides means for injecting a small quantity of liquid refrigerant into the compression chamber 4 during each compression cycle of the rotor. The liquid refrigerant mixes with the semi-compressed gas in the high pressure side of the chamber and greatly reduces the discharge temperature of this gas. More specifically, there is provided an injector port 31 opening into the compression chamber and extending through one end wall of the cylinder. As may be seen in FIGURES 4 and 5, the injector port 31 is disposed directly beneath the bottom edge 14b of the vane 14 which reciprocates back and forth as the rotor moves around the chamber 4. The bottom edge 14b seals off the port at all times during the compression cycle except for a period when a notch 32 aligns with the injection port 31 and permits flow of liquid refrigerant into the chamber. The notch 32 is positioned in the vane 14 to open the injection port when the gas pressure in the high pressure side 4b of the compression chamber 4 is between 50% and of discharge pressure. The notch 32 is formed so that it opens on the high pressure side 14a of the blade. The top or roof of the notch is slanted toward the high pressure side 4b of the chamber so that liquid refrigerant injected through the port 31 impinges against the roof of the notch and is directed toward the gas being forced around the chamber by the rotor.

As may be seen in FIGURES 1 and 3, means are provided for introducing liquid refrigerant into the injection port from a source of condensed refrigerant in the refrigeration system. In the illustrated embodiment of the invention, liquid refrigerant is introduced into the injection port 31 through a passage which includes the line or conduit 33, connecting with the condenser 22 in the latter stages thereof where the refrigerant is normally in liquid form. As may be seen in FIGURE 1, in addition to the conduit 33, the passage includes a larger tube 34 which enters the case 2 and passes upwardly through the oil sump 24 in the bottom of the hermetic case 2. The tube 34 is attached to the bottom plate 10 by means of a connecting stud 35 containing an aperture in alignment with the injection port 31. A small capillary or tube 36 extends from the center of the stud 35 into the lower regions of the tube 34 Where it is constantly immersed in liquid refrigerant within the tube 34 and completes the liquid refrigerant supply passage to the injector port 31. It will be noted that the opening between the tube 33 and the tube 36 permits liquid refrigerant to flow into the larger tube 34. This arrangement provides a liquid refrigerant reservoir covering the end of the tube 36 and creates a refrigerant gas trap or expansion chamber 3401 within the larger tube 34. The expansion chamber 34a serves to damp liquid impulses or vibrations created by the intermittent opening and closing of the injector port 31 by the reciprocating action of the blade 14 during rotation of the rotor 6 around the compression chamber 4. A capillary 37 in the line 33 limits the How through the liquid supply passage and prevents short circuiting of the evaporator 15.

Referring now to the schematic diagram of FIGURE 4, it may be seen that the bottom 14b of the blade 14 seals the injection port 31 at all times during the compression cycle of the rotor 6 except during the period when the contacting or peripheral surface 6a of the rotor moves from point A to point C of the annular chamber 4. It will be noted that when the peripheral surface 6a of the rotor engages point A of the chamber, the notch 32 is just beginning to uncover the liquid injection port 31. When the peripheral surface 6a is at point C, the notch 32 has moved into the slot 13 and the bottom 14b of the vane has again closed the port 31. In the illustrated embodiment of the invention, the location of point A is approximately 245 in advance of the completion of the compression stroke or in advance of the center line 38 of the blade 14. In a tested compressor unit having the relative dimensions of the compressor shown in the drawings, the pressure of the gas within the high pressure side 4b of the chamber, when the rotor surface 6a engages point A, was approximately 160 p.s.i.g. or approximately 50% of the pressure of the gas within the hermetic case 2. Point C is located approximately 140 in advance of the completion of the compression stroke or in advance of the center line 38 of the blade 14. When the peripheral surface of the rotor of the tested compressor engaged point C, the pressure within the high pressure side 4b of the chamber was approximately 290 p.s.i.g., which is about 95% of the pressure within the hermetic casing 2. Thus the injection port is opened when the pressure within the compression chamber is between 50% and 95% of the pressure within the case. It should be noted that the injection port 31 is closed whenever the pressure within the compression chamber exceeds 290 p.s.i.g. or before the pressure within the compression chamber exceeds the case pressure, which is only slightly above the pressure within the condenser from which the liquid refrigerant flowing into the injector port 31 is supplied. The average pressure of the gas within the compression side 4b of the chamber 4,

when the opening of the liquid injection port was unsealed by the notch of the vane 14, was about 225 p.s.i.g. This is only an average of 75 p.s.i.g. below discharge pressure and, although it permits some expansion or flashing of the liquid refrigerant being injected into the expansion chamber to cool the gas being compressed therein, it does not too greatly effect the efficiency of the compressor.

However, the pressure within the compression chamber 4, when the injection port is uncovered, is always below that within the condenser 22 so that liquid refrigerant is induced to flow through the liquid refrigerant supply passage toward the relatively lower pressure of the compression chamber to be injected into the chamber. Yet, the opening of the injection port 31 occurs only when the rotor 6 has moved to point A, ,the pressure within the chamber is much above suction pressure, or, as stated previously, is approximately 50% of case pressure before injection occurs. This prevents flooding of the compression chamber with liquid refrigerant which, of course, would affect the efficiency of the compressor unit.

It will be noted that, at all times during injection of liquid refrigerant into the compression chamber, the suction port 17 is sealed by the peripheral surface 6a of the rotor from that portion of the chamber into which the liquid refrigerant is being injected. That is, the peripheral surface 6a, in contact with the annular chamber 4, has moved past the edge 17a of the suction port 17 and liquid refrigerant is only injected into the high pressure side of the chamber. Thus all of the suction gas trapped in the high pressure side 4b of the chamber is Within the chamber at the time that the liquid refrigerant is injected therein for cooling purposes.

Referring now to FIGURES 6 and 7 there is shown another embodiment of the invention. In this embodiment the vane 14 is provided with a groove or passage 41 that is milled or otherwise formed so that at least a part thereof may open on the high pressure side 14a of the vane. In the illustrated embodiment the groove extends longitudinally along the side of the vane and is covered and uncovered by the side of the radial slot 13 as the vane reciprocates back and forth within the slot. Liquid refrigerant is introduced into the groove 41 from a source of liquid refrigerant, such as the latter stages of the condenser, by means of a liquid refrigerant supply passage including a passage or channel portion 42 formed in the cylinder housing 5. In this embodiment, the pas sage 42 extends upwardly along the side of the radial slot 13 and at all times communicates with the groove 41 in the vane. The liquid supply conduit may include, as in the previously described embodiment, the conduit 33 and capillary 37 which connect with the liquid portions of the condenser. The conduit 33 may connect directly with the channel or passage 42 or may include a port through the end plate 10 which mates with the passage 42. It is obvious that the passage 42 may be formed in any other part of the cylinder or housing 5 and the only limiting feature is that it must communicate at its end thereof with the groove or passage 41 in the vane 14.

The groove 41 is formed in the vane 14 so that the end 41a of the groove opens into the chamber 412 just as the peripheral surface 6a of the rotor 6 reaches the point A and is closed to the chamber by the edge 13b of the side of the radial slot 13 as the peripheral surface 6a reaches point C, as shown in FIGURE 7. As in the previous embodiment of the invention, the groove 41 is exposed to the chamber when the gas pressure therein is between 50% and of the pressure within the case. Thus, the groove 41 injects a small quantity of liquid refrigerant into the chamber 4 during each compression stroke of the rotor 6. This refrigerant flashes into gaseous form, upon encountering the hot semi-compressed gas in the chamber, to become mixed therewith and greatly reduces the temperature of the gas being discharged from the chamber.

It should be mentioned that the injected liquid greatly cools the semi-compressed gas as it is being compressed and reduces the work of compression of this gas. This counteracts the small increase in work required to compress the gas which flashes into the chamber from the injected liquid refrigerant. That is, although there is necessarily some additional gas to compress, the great reduction in temperature of all of the gas within the chamber compensates sufliciently to result in no increased work input.

The reduction of the compression temperature of the mixture discharged from the chamber is sufficient to permit the gas to be passed directly over the motor for cooling purposes without any further precooling. The low compression temperature also reduces the tendency of both the refrigerant and oil in the system to deteriorate and to deposit on the valves and other moving parts of the system and, thus, prolongs the life of the system.

While in accordance with the Patent Statutes there has been described what at present is considered to be the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and it is, therefore, the aim of the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A hermetically sealed refrigerant compressor adapted for use in a refrigeration system comprising a hermetic casing adapted to contain a high pressure refrigerant gas, a compressor unit in said casing including a cylinder having an annular compression chamber, a rotor eccentrically rotatable within said chamber, a drive motor mounted in said hermetic casing and including a shaft extending into said cylinder for driving said rotor in an eccentric motion around said chamber so that the peripheral surface of said rotor moves progressively into sealing relation with successive portions of said annular chamber, a radial slot in said cylinder communicating with said chamber, a vane mounted in said radial slot and biased against the outer periphery of said rotor for dividing said chamber into high and low pressure sides, means including a suction inlet opening communicating with said annular chamber for introducing low pressure refrigerant gas into said annular chamber, means including a gas discharge opening communicating with said annular chamber for conducting hot compressed refrigerant gas from said chamber into said hermetic casing, a refrigerant condensing means in said system for condensing high pressure gaseous refrigerant within said system to a liquid, means for injecting condensed liquid refrigerant into said annular chamber from said refrigerant condensing means in said system including an injection passage in said vane having an opening therein adapted to communicate with said high pressure side of said annular chamber when said blade moves into said chamber thereby to inject a small quantity of liquid refrigerant into said chamber during each cycle of rotation of said rotor around said chamber and a liquid refrigerant supply passage having one end communicating with said injection passage in said blade and the other end connecting with said refrigerant condensing means in said system.

2. A hermetically sealed refrigerant compressor adapted for use in a refrigeration system comprising a hermetic casing adapted to contain a high pressure refrigerant gas, a compressor unit in said casing including a cylinder having an annular compression chamber and end walls enclosing the ends of said annular chamber, a rotor eccentrically rotatable within said chamber, a drive motor mounted within said hermetic casing and including a shaft extending through one of said end walls of said cylinder for driving said rotor in an eccentric motion around said chamber so that the peripheral surface of said rotor moves progressively into sealing relation with successive portions of said annular chamber, a radial slot in said cylinder communicating with said chamber, a vane mounted in said radial slot and biased against the outer periphery of said rotor for dividing said chamber into high and low pressure sides, means including a suction inlet opening communicating with said annular chamber for introducing low pressure refrigerant gas into said annular chamber, means including a gas discharge opening communicating with said annular chamber for conducting hot compressed refrigerant gas from said chamber into said hermetic cas ing, a refrigerant condensing means in said system for condensing high pressure gaseous refrigerant within said system to a liquid, means for injecting condensed liquid refrigerant into said annular chamber including a liquid refrigerant supply passage connecting at one end with said refrigerant condensing means in said system, an injection port communicating with said liquid refrigerant supply passage and disposed in one end wall of said cylinder and opening into said chamber, said refrigerant injection port being so disposed in said chamber as to be covered by said vane when said vane moves into said chamber, a notch formed in said vane and adapted to communicate with said high pressure side of said chamber when said vane moves into said chamber, said notch in said vane having a portion thereof adapted to align with said injection port as said vane moves into said chamber thereby to inject liquid refrigerant into said chamber during each cycle of rotation of said rotor around said chamber.

3. A hermetically sealed refrigerant compressor adapted for use in a refrigeration system comprising a hermetic casing adapted to contain a high pressure refrigerant gas, a compressor unit in said casing including a cylinder having an annular compression chamber and end walls closing the ends of said annular chamber, a rotor mounted in said chamber for eccentric rotation therein, a drive motor mounted in said hermetic case and including a shaft extending through one end wall of said cylinder for driving said rotor around said chamber so that the peripheral surface of said rotor moves progressively into sealing relation with successive portions of said annular chamber, a radial slot in said cylinder communicating with said chamber, a vane slidably positioned in said radial slot, means biasing said vane against said peripheral surface of said rotor for following said peripheral surface of said rotor thereby to divide said chamber into a high pressure side on one side of said blade and a low pressure side on the other side of said blade, means including a suction inlet opening communicating with said annular chamber for introducing low pressure refrigerant gas from said system into said chamber, means including a gas discharge opening communicating with said annular chamber for conducting compressed refrigerant gas from said chamber into said hermetic casing, a refrigerant condensing means in said system for condensing high pressure gaseous refrigerant within said system to a liquid, means for injecting liquid refrigerant into said annular chamber including a liquid refrigerant supply passage connecting at one end with said refrigerant condensing means in said system, an injector port communicating with said liquid refrigerant supply passage and disposed in one end wall of said cylinder, said injection port opening into said chamber at a point covered by said vane as said vane moves into said chamber, a notch in said vane extending from the edge thereof adjacent said injector port to said high pressure side of said vane, said notch being so constructed and arranged on said vane as to align with said opening of said injector port when the pressure of refrigerant gas in said high pressure side of said chamber is within the range of 50 to of the pressure of said high pressure refrigerant gas in said case.

4. A hermetically sealed refrigerant compressor adapted for use in a refrigeration system comprising a hermetic casing adapted to contain a high pressure refrigerant gas, a compressor unit in said casing including a cylinder having an annular compression chamber and end walls enclosing the ends of said annular chamber, a rotor mounted in said chamber for eccentric rotation therein, a drive motor mounted in said hermetic case and including a shaft extending through one end wall of said cylinder for driving said rotor around said chamber so that the peripheral surface of said rotor moves progressively into sealing relation with successive portions of said annular chamber, a radial slot in said cylinder communicating with said chamber, a vane slidably positioned in said radial slot, means biasing said 'vane against said peripheral surface of said rotor for following said peripheral surface of said rotor thereby to divide said chamber into a high pressure side on one side of said blade and a low pressure side on the other side of said blade, means including a suction inlet opening communicating with said annular chamber for introducing low pressure refrigerant gas from said system into said chamber, means including a gas discharge opening communicating with said annular chamber for conducting compressed refrigerant gas from said chamber into said hermetic casing, a refrigerant condensing means in said system for condensing high pressure gaseous refrigerant within said system to a liquid, means for injecting liquid refrigerant into said annular chamber including a liquid refrigerant supply passage connecting at one end with said refrigerant condensing means in said system, an injector port communicating with said liquid refrigerant supply passage and disposed in one end wall of said cylinder, said injection port opening into said chamber at a point covered by said vane as said vane moves into said chamber, a notch in said vane extending from the edge thereof adjacent said injector port through said high pressure side of said vane, said notch in said vane adapted to align with said injection port as said vane moves into said chamber, said notch having a surface arranged at an angle with respect to the discharge axis of said injector port so that liquid refrigerant injected into said notch is deflected into said chamber during each cycle of rotation of said rotor around said chamber.

5. A hermetically sealed refrigerant compressor adapted for use in a refrigeration system comprising a hermetic casing adapted to contain a high pressure refrigerant gas, a compressor unit in said casing including a cylinder having an annular compression chamber, a rotor eccentrically rotatable within said chamber, a drive motor mounted in said hermetic casing above said compressor unit and having a shaft extending into said cylinder for driving said rotor in an eccentric motion around said chamber so that the peripheral surface of said rotor moves progressively into sealing relation with successive portions of said annular chamber, a radial slot in said cylinder communicating with said chamber, a vane mounted in said radial slot and biased against the outer periphery of said rotor for dividing said chamber into high and low pressure sides, means including a suction inlet opening communicating with said annular chamber for introducing low pressure refrigerant gas intosaid annular chamber, means including a gas discharge opening communicating with said annular chamber for conducting hot compressed refrigerant gas from said chamber into said hermetic casing, a refrigerant condensing means in said system for condensing high pressure gaseous refrigerant within said system to a liquid, means for injecting condensed refrigerant into said chamher from said refrigerant condensing means in said system including an injection groove in the side of said vane exposed to the high pressure side of said annular chamber, said groove being so constructed and arranged on the side of said vane as to have a portion thereof communicating with said chamber when the pressure of refrigerant in said high pressure side of said chamber is within the range of to of the pressure of said high pressure refri'gerant gas in said case, passage means in said cylinder communicating with said injection groove in said vane to deliver liquid refrigerant thereto, and a liquid refrigerant supply passage communicating at one end with said passage means in said cylinder and connecting at the other end with said refrigerant condensing means in said system thereby to deliver liquid refrigerant to said injection groove in said Wane for injection into said chamber as said blade moves into said chamber during each cycle of said rotor within said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 2,247,950 Kucher July 1, 1941 2,577,107 Cooper Dec. 4, 1951 2,967,410 Schulze Jan. 10, 1-961 2,988,267 Rosefield June 13, 1961

Claims

1. A HERMETICALLY SEALED REFRIGERANT COMPRESSOR ADAPTED FOR USE IN A REFRIGERATION SYSTEM COMPRISING A HERMETIC CASING ADAPTED TO CONTAIN A HIGH PRESSURE REFRIGERANT GAS, A COMPRESSOR UNIT IN SAID CASING INCLUDING A CYLINDER HAVING AN ANNULAR COMPRESSION CHAMBER, A ROTOR ECCENTRICALLY ROTATABLE WITHIN SAID CHAMBER, A DRIVE MOTOR MOUNTED IN SAID HERMETIC CASING AND INCLUDING A SHAFT EXTENDING INTO SAID CYLINDER FOR DRIVING SAID ROTOR IN AN ECCENTRIC MOTION AROUND SAID CHAMBER SO THAT THE PERIPHERAL SURFACE OF SAID ROTOR MOVES PROGRESSIVELY INTO SEALING RELATION WITH SUCCESSIVE PORTIONS OF SAID ANNULAR CHAMBER, A RADIAL SLOT IN SAID CYLINDER COMMUNICATING WITH SAID CHAMBER, A VANE MOUNTED IN SAID RADIAL SLOT AND BIASED AGAINST THE OUTER PERIPHERY OF SAID ROTOR FOR DIVIDING SAID CHAMBER INTO HIGH AND LOW PRESSURE SIDES, MEANS INCLUDING A SUCTION INLET OPENING COMMUNICATING WITH SAID ANNULAR CHAMBER FOR INTRODUCING LOW PRESSURE REFRIGERANT GAS INTO SAID ANNULAR CHAMBER, MEANS INCLUDING A GAS DISCHARGE OPENING COMMUNICATING WITH SAID ANNULAR CHAMBER FOR CONDUCTING HOT COMPRESSED REFRIGERANT GAS FROM SAID CHAMBER INTO SAID HERMETIC CASING, A REFRIGERANT CONDENSING MEANS IN SAID SYSTEM FOR CONDENSING HIGH PRESSURE GASEOUS REFRIGERANT WITHIN SAID SYSTEM TO A LIQUID, MEANS FOR INJECTING CONDENSED LIQUID REFRIGERANT INTO SAID ANNULAR CHAMBER FROM SAID REFRIGERANT CONDENSING MEANS IN SAID SYSTEM INCLUDING AN INJECTION PASSAGE IN SAID VANE HAVING AN OPENING THEREIN ADAPTED TO COMMUNICATE WITH SAID HIGH PRESSURE SIDE OF SAID ANNULAR CHAMBER WHEN SAID BLADE MOVES INTO SAID CHAMBER THEREBY TO INJECT A SMALL QUANTITY OF LIQUID REFRIGERANT INTO SAID CHAMBER DURING EACH CYCLE OF ROTATION OF SAID ROTOR AROUND SAID CHAMBER AND A LIQUID REFRIGERANT SUPPLY PASSAGE HAVING ONE END COMMUNICATING WITH SAID INJECTION PASSAGE IN SAID BLADE AND THE OTHER END CONNECTING WITH SAID REFRIGERANT CONDENSING MEANS IN SAID SYSTEM.