US3891358A

US3891358A - Suction valve for rotary compressor

Info

Publication number: US3891358A
Authority: US
Inventors: William T Ladusaw
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1973-06-25
Filing date: 1974-04-29
Publication date: 1975-06-24
Anticipated expiration: 1992-06-24

Abstract

A suction valve having a chamber including an outlet communicating with the suction port of a rotary compressor, an inlet for receiving a flow of gas, a valve holding area having a film of liquid arranged opposite the inlet and a valve movable between the inlet and the holding area. The liquid has a viscosity sufficient to create a surface tension which will maintain the valve in the holding area during the flow of gas and to permit the valve to break the surface tension a predetermined time after the termination of the gas flow.

Description

ate 1 1 1 Ladusaw 1 SUCTION VALVE FOR ROTARY COMPRESSOR [75] Inventor: William T. Ladusaw, Louisville, Ky.

[73] Assignee: General Electric Company,

Louisville, Ky.

[22] Filed: Apr. 29, 1974 [21] App]. No.: 464,893

Related US. Application Data [63] Continuation-in-part of Ser. No. 373.188, June 25,

1973, abandoned.

[52] US. Cl 418/63; 137/513.11 [51] Int. Cl. ..F01c 1/02 [58] Field of Search. 418/63; 137/2, 519.5, 533.13,

[56] References Cited UNITED STATES PATENTS 1,543,163 6/1925 Johnson et a1 418/63 1,989,199 1/1935 Hummert 137/533.13 2,278,715 4/1942 Stoyke et a1. l37/533.13

[ June 24, 11975 2,332,787 10/1943 Fleming l37/533.l3 2,395,065 2/1946 Rataiczak 418/63 2,591,174 4/1952 Martin 137/533.13 3,105,633 10/1963 Dellario 418/63 FOREIGN PATENTS OR APPLICATIONS 131,876 1919 United Kingdom Primary ExaminerWil1iam L. Freeh Assistant ExaminerG. P. LaPointe [57] ABSTRACT A suction valve having a chamber including an outlet communicating with the suction port of a rotary compressor, an inlet for receiving; a flow of gas, a valve holding area having a film of liquid arranged opposite the inlet and a valve movable between the inlet and the holding area. The liquid has a viscosity sufficient to create a surface tension which will maintain the valve in the holding area during the flow of gas and to permit the valve to break the surface tension a predetermined time after the termination of the gas flow.

7 Claims, 6 Drawing Figures JUN24 9 PATENTED 5 SHEET 1 V JBSLBSB PATENTEDJIJM 24 1975 I SHEET W m A V6 I SUCTION VALVE FOR ROTARY COMPRESSOR CROSS REFERENCE TO RELATED APPLICATION BACKGROUND OF THE INVENTION A well-known type of rotary compressor comprises a cylindrical wall member and end plates defining a compression chamber or cylinder, a rotor centrally mounted within the cylinder and a vane slidably mounted within the cylindrical wall for engagement with the periphery of the rotor to divide the chamber into a high pressure side and a lower pressure side. In the operation of such compressor, rotation of the rotor draws the gas into the low pressure side and discharges the compressed gas through a discharge port communicating with the high pressure side of the chamber on the opposite side of the vane from the lower pressure port. When such compressor operates intermittently, as for example, when it forms part of a hermetic refrigeration system, valve means are provided to prevent re verse flow through the suction port which may take place for example due to the leakage of high pressure gas between the rotor and the cylinder wall to the lower pressure side and then to the low side of the system when the compressor is stopped. In rotary compressors, including suction port valves, the valve is normally positioned in the suction passage at a point somewhat remote from the compression chamber and has frequently taken the form of a simple ball or check valve in the suction passage as shown in US. Pat. No. 3,015,222-Wellborn et al.

When ball check valves have been employed in conjunction with rotary compressors they have been found to be noisy during operation of the compressor due to their constant movement in the guide area because of the pulsing of the intake gas. This noise generated by a ball valve is undesirable, especially in air conditioning units that are mounted in the window or wall of an enclosure such as a sleeping area.

SUMMARY OF THE INVENTION A suction valve having a chamber including an outlet communicating with the suction port of a rotary compressor, an inlet for receiving a pulsing flow of gas, a valve holding means having a film of liquid, and a valve member disposed in the chamber, being movable from the inlet to the holding means by the incoming flow of gas entering the inlet. The surface tension of the liquid between the engaging valve surface and the surface area of the holding means is sufficient to maintain the valve in the holding means during the flow of pulsing gas and to permit the valve to break the surface tension a predetermined time after the termination of the gas flow.

An object of the invention is to provide means responsive to the flow of refrigerant gas during operation of the compressor that is effective to hold the valve stationary in an open position and to release the valve in response to the termination of the compressor operation to allow the valve to return by gravity to its normal closed position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view partially in crosssection ofa hermetic refrigeration compressor incorporating the present invention;

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

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

FIG. 4 is an enlarged fragmentary sectional view taken along the line 4-4 of FIG. 2;

FIG. 5 is a perspective view of the ball retainer means employed by the present invention; and

FIG. 6 is an elevational view in section illustrating a second embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there is shown a hermetic compressor 10 including a hermetic casing 12 in which there is disposed a refrigerant compressor unit 14 having an angular chamber or compressor chamber 16 de fined within a cylinder or housing 18. Disposed for rotation within the chamber 16 is a rotor 20 which is driven by an eccentric 22 formed as an integral part of the drive shaft 24 extending downwardly from the motor 26. A bearing formed in the supporting main frame 28, supports the shaft 24 above the eccentric 22 for rotation by the motor 26. It should be noted that the upper end wall enclosing the angular compressor chamber 16 is provided by the main frame 28. The main frame 28 also supports the compressor unit 14 within the hermetic casing 12. The opposite or lower end wall 30 of the compressor chamber 16 also supports the lower end of the shaft 24.

As may best be seen in FIG. 2, the cylinder 18 is provided with a radial slot 32 having slidably disposed therein a blade or vane 34 which is biased into engagement with the peripheral surface of the rotor 20 thereby dividing the chamber '16 into a low and high pressure side respectively designated as 36 and 38.

As may be seen in FIG. 3, the hermetic compressor 10 is adapted to be connected into a refrigeration system to receive suction gas from an evaporator 40 through a suction line 42. Means are provided for delivering the suction gas into the low pressure side 36 of the chamber 16 from the suction line 42. More specifically, referring to FIG. 2, these means include chamber or channel 43 having an inlet area 44 formed in the cylinder 18 and communicating with the compressor chamber 16. The inlet area 44 delivers low pressure gas into the low pressure side of 36 of the compression chamber 16 where it is compressed between the peripheral surface of the rotor 20, the sides of the angular chamber 16, and the high pressure side of the vane 34, during rotation of the rotor 20 around the chamber.

Means, including a discharge port 46 and discharge chamber 48, are provided for discharging the high pressure gas from the high pressure side 38 of the angular chamber 16 into the hermetic casing 12. Mounted within the discharge chamber 48 is a suitable valve 50 for assuring proper compression of the gas issuing through the discharge port 46 and preventing reverse flow of gas back into the compression chamber 16. As may be seen in FIG. 1, the high pressure gas from the discharge chamber 48 flows into the hermetic casing 12 through a passage 52 formed in the main frame 28. After flowing upwardly over the motor 26 the high pressure gas is conducted out of the hermetic casing 12 through a suitable discharge means or outlet in the upper end of the case. The gas then flows through a discharge line 54 shown only in FIG. 3 into the condenser 56 where the heat absorbed by the refrigerant in the other portions of the system is abstracted. As the gas in the condenser 56 is cooled it condenses so that the re frigerant in the latter stage of the condenser is therefore largely in liquid form.

The present invention is particularly directed to the provision of an improved inlet or suction valve means, generally designated by the numeral 58, which will seal the compressor inlet or suction port 60 as shown in FIG. 4 in a predetermined minimum amount of time following termination of inward refrigerant flow through the compressor inlet 60 to avoid or minimize the aforementioned problem of reverse rotation of the compressor. To this end, and in accordance with the presently preferred form of the present invention, the chamber 43 of the compressor block 14 is generally vertically arranged between the upper and lower plates. The inlet from the evaporator carrying the refrigerant to the compressor communicates through the lower plate to a valve seat 62 formed in said plate. This presently preferred form of the inlet valve means of the present invention includes a ball 64 that is movably mounted within the inlet chamber 43. The ball 64 is made of a size and mass such that, in the absence of inward flow of fluid through the compressor inlet into the inlet port 60, the ball will move downwardly by gravity to seal the inlet 62, FIG. 4, but will move upwardly to open the inlet in response to such inward flow of the refrigerant through the compressor inlet 60, and into the chamber 43.

It should be understood that while a ball valve is used in the present embodiment any valve member operating as a ball valve may be employed such as a plunger having spherical ends which would by gravity normally remainin a closed position.

During initial gas flow the valve 64 assumes the position indicated by dotted lines in FIG. 4. However, during low pressure portion of the compressor cycle the ball valve 64 by gravity moves away from the upper plate 28 and the following high pressure portion of the cycle causes the ball valve to once again be driven against the upper plate 28. During the high speed operation of the rotary compressor an objectional clattering noise would result if the ball valve 64 were permitted .to pulseagainst the plate 28 with the pulsing of the incoming gas.

Means are therefore provided in the present embodiment to hold the ball valve 64 to prevent the objectional clattering and resultant wear during the operation of the compressor. To this end, as best seen in FIG. 4 the upper plate opposite the inlet 60 is provided with a recess or holding area 69 formed by a concave surface area being a substantially spherical segment 68 which in the present embodiment is substantially complementary to the ball valve 64. However, as will be hereinafter explained the precise shape and dimension including the surface area of the segment 68 may vary in accordance with other factors.

As is well known in the refrigerant art a small quantity of oil or lubricant is entrained in and carried throughout the refrigerant system by the refrigerant. This small amount of oil which is mixed with the refrigerant gas is sufficient to cover the internal parts of the compressor with a film of oil. Thus, the spherical surface area 68 of the holding area 69 is coated with a film of gas and lubricant which is effective in providing enough surface tension to maintain the ball 64 in the holding area 69 and in contact with the surface area 68 as shown in dotted lines in FIG. 4 while the compressor 14 is operating and particularly during the low pressure portion of the compressor cycle. The holding area 69 is dimensioned in combination with the particular ball and oil used to accommodate both the ball 64 and the thickness of the film of oil. In effect, the ball 64 is maintained in the holding area 69 and against the surface area 68 during that time when the rotor is between points A and B as seen in FIG. 2 and there is very low flow of refrigerant or suction gas into the compression chamber 16. When operation of the compressor terminates and the flow of suction gas terminates, the weight of the ball 64 is sufficient to break the surface tension between the ball 64 and the surface 68 caused by the film of oil and the ball drops freely onto the valve seat 62 to prevent reverse flow.

While the suction valve embodying the present invention is shown incorporated within the cylinder housing of the compressor it should be understood the valve could be a separate component from the compressor and be inserted in the suction line of the refrigeration system. Accordingly referring now to FIG. 6, there is shown a second embodiment of the invention wherein parts identical to those of the embodiment of FIGS. 1-5 are shown by the same numerals.

It should be apparent from the above description that the exact configuration of the parts must be determined for each specific application of the principles of the present invention. More specifically in carrying out the present invention it should be understood that the pressure of incoming refrigerant gas including the type of refrigerant used, the size and weight of the ball valve 64, the exact surface area 68, dimensions or configuration of the holding area 69, the type of lubricant and amount used, including the speed of rotation of the compressor, are all factors in carrying out the teachings of the present invention. Since all of the above factors may be variables, providing a ball valve 64 that is positively held in an open position to prevent clattering during low refrigerant flow portion of the rotary compressor operation and for releasing the ball valve 64 at predetermined time after termination of compressor operation to prevent reverse flow of refrigerant gas requires a certain amount of experimentation. Accordingly, the following list is intended to show the parameters used to carry out the present embodiment. It should be understood that in carrying out other embodiments such as the embodiment shown in FIG. 6 other parameters might be necessary.

VALVE 64 Weight 16.3 grams Dia. .625 VISCOSITY Oil & R22 S.U.S 50-100 Oil S.U.S 200 GAS Type R22 Temp. 60F F Flow 250 370 Ib/hr Velocity 540 ft/min 840 ft/min HOLDING AREA 69 Surface Area 68 .2474 in. Radius .315 COMPRESSOR RPM 2.500 3,500 RPM In accordance with the present embodiment of the invention, retainer means 70 is provided in the inlet area 44 which is effective in maintaining the ball valve 64 in vertical alignment between the inlet 60 and the holding area 66. As shown in FIGS. 2 and 4 and particularly FIG. 5, the retaining means 70 comprises a body portion 72 formed to provide a cylindrical retaining area 74 dimensioned to allow free vertical movement of the ball valve 64. The body portion 72 is provided with an open vertical area 76 through which refrigerant can communicate between the inlet 60 and the compression chamber 16 when the ball valve 64 is in its open or up position. In order to secure and locate the retainer 70 in the inlet area 44, the free ends of the body portion 72 adjacent the opening 76 are provided with flanges 78 which slidably engage slots 80 (FIG. 2) formed in the housing 18.

In addition to providing a means for retaining the ball valve 64 in proper vertical alignment between the valve seat 62 and the holding area 66 the retainer 70 is generally constructed of a harder material than the housing 18 and thereby provides surface that is relatively less susceptible to wear by action of the ball valve 64. The retainer 70, in effect, prevents the constant movement or pulsing of the valve 64 from causing particles of oxide to chip or flake off the cylinder.

The above feature of providing a relatively hard wear surface for the ball valve 64 is important to the life of the compressor unit in that particles from the housing 18 that may be entrapped in the system can cause compressor failure.

It should be apparent to those skilled in the art that while what has been described is considered at the present to be the preferred embodiment of this invention, in accordance with the Patent Statutes, changes may be made in the disclosed ball check valve without actually departing from the true spirit and scope of this invention.

While there has been shown and described a specific embodiment of the invention, it will be understood that it is not limited thereto and it is intended by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

l. A rotary compressor comprising:

a cylindrical wall member and upper and lower end plate members defining an annular compression chamber for receiving a charge of refrigerant;

an inlet chamber in said cylindrical wall member extending between said upper and lower end plates and communicating with said compression chamber;

a suction port in said lower end plate including a valve seat communicating with said channel;

a valve member arranged for vertical movement in said inlet area between said valve seat and said upper plate when a refrigerant charge is introduced into said compression chamber during the operation of said compressor;

valve member holding means having a film of lubricant being formed in said upper plate in communication with the upper extremities of said inlet area for receiving a portion of said valve during operation of said compressor; and

said valve member holding means having a predetermined surface area relative to said portion of said valve member being dimensioned so that the surface tension of said lubricant between said valve and said holding means surface area is sufficient to retain said valve in said holding means during operation of said compressor and for releasing said valve to close against said valve seat when said compressor operation terminates.

2. A compressor as set forth in claim 1 wherein said valve member is a ball valve and said holding means being a concave spherical segment.

3. A compressor as set forth in claim 2 wherein a retaining means removably secured in said channel means for holding said ball valve in said channel means.

4. A compressor as set forth in claim 3 wherein said retaining means being joined by an arcuate section to provide a circular guideway for said ball valve extending vertically substantially between said upper and lower plates.

5. A compressor as set forth in claim 4 wherein said retaining means having radially projecting bars formed along the vertically disposed free ends for engaging slots in said channel means for locating and removably securing said retaining means in said channel means.

6. A suction valve comprising:

a valve chamber including an inlet port for receiving a flow of gas, a valve holding means having a predetermined surface area opposite the inlet port, and an outlet port intermediate the inlet port and hold ing surface;

a valve member in the chamber operable in response to said gas flow for carrying said valve member to engage said holding means, said valve member having a surface thereof engaging the holding means surface area being shaped to be in substantial conformity with the configuration of the holding sur face;

means for providing a restoring force to urge the valve toward the inlet port; and

a liquid film between the valve surface, and the hold ing means surface area, said liquid being of a viscosity sufficient to produce a surface tension in relation to the degree of conforming engagement between the valve surface and the holding means surface area to maintain said valve in contact with said holding means surface area and to overcome the restoring force for at least a predetermined amount of time.

7. A suction valve according to claim 6 wherein said liquid is a mixture of refrigerant gas and lubricant.

=l l l

Claims

1. A rotary compressor comprising: a cylindrical wall member and upper and lower end plate members defining an annular compression chamber for receiving a charge of refrigerant; an inlet chamber in said cylindrical wall member extending between said upper and lower end plates and communicating with said compression chamber; a suction port in said lower end plate including a valve seat communicating with said channel; a valve member arranged for vertical movement in said inlet area between said valve seat and said upper plate when a refrigerant charge is introduced into said compression chamber during the operation of said compressor; valve member holding means having a film of lubricant being formed in said upper plate in communication with the upper extremities of said inlet area for receiving a portion of said valve during operation of said compressor; and said valve member holding means having a predetermined surface area relative to said portion of said valve member being dimensioned so that the surface tension of said lubricant between said valve and said holding means surface area is sufficient to retain said valve in said holding means during operation of said compressor and for releasing said valve to close against said valve seat when said compressor operation terminates.

6. A suction valve comprising: a valve chamber including an inlet port for receiving a flow of gas, a valve holding means having a predetermined surface area opposite the inlet port, and an outlet port intermediate the inlet port and holding surface; a valve member in the chamber operable in response to said gas flow for carrying said valve member to engage said holding means, said valve member having a surface thereof engaging the holding means surface area being shaped to be in substantial conformity with the configuration of the holding surface; means for providing a restoring force to urge the valve toward the inlet port; and a liquid film between the valve surface, and the holding means surface area, said liquid being of a viscosity sufficient to produce a surface tension in relation to the degree of conforming engagement between the valve surface and the holding means surface area to maintain said valve in contact with said holding means surface area and to overcome the restoring force for at least a predetermined amount of time.