Suction and discharge mechanisms for an appliance refrigerant compressor   

FIELD OF THE INVENTION

The present invention relates to suction and discharge mechanisms for the compressor of an appliance refrigeration cycle.

BACKGROUND OF THE INVENTION

Refrigerant compressors are used in a variety of appliances including refrigerators, freezers, and heat pump dryers. Conventionally, such refrigerant compressors having a reciprocating piston or other device for compressing refrigerant vapor to a higher pressure within a cylinder or other chamber. After the refrigerant is compressed by the stroke of the piston that reduces the volume of the refrigerant within the cylinder, the refrigerant is discharged through a single discharge port that is opened by a discharge valve. During this compression stroke, a suction valve for providing refrigerant into the cylinder through a suction port is closed.

As the piston is withdrawn so as to increase the volume available for refrigerant within the cylinder, refrigerant is drawn through a single suction port that is opened by a suction valve. As the refrigerant enters into the cylinder, it must flow through the suction port and around the suction valve. During this intake stroke, the discharge valve for the flow of refrigerant out of the cylinder through the discharge port is closed.

The flow of refrigerant through the suction and discharge ports as well as around the suction valve creates an undesirable pressure drop in the refrigerant due to skin friction, shear flow and expansion-contraction losses. A resultant energy loss occurs that lowers the overall energy efficiency ratio (EER) of the refrigerant compressor and, therefore, lowers the performance of the appliance in which it operates. Stated alternatively, additional energy is consumed in operating the compressor due to these inefficiencies in a conventional refrigerant compressor.

Accordingly, a refrigerant compressor having suction and/or discharge valves providing improved energy efficiency would be beneficial. More particularly, suction and discharge valves that can provide for a reduction in pressure drop owing to reduction in friction losses and more streamlined flow would be useful. Such valves that can provide an increased coefficient of discharge and higher volumetric efficiency would also be particularly beneficial.

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

In one exemplary embodiment, the present invention provides a refrigerant compressor that includes a cylinder for receipt of refrigerant to be compressed; a piston received within the cylinder and configured for reciprocating movement; and a suction port for the receipt of refrigerant into the cylinder. A suction valve is positioned at the suction port and configured for opening to allow refrigerant through the suction port and into the cylinder. A first discharge port is provided for the discharge of refrigerant from the cylinder. A second discharge port is also provided for the discharge of refrigerant from the cylinder. At least one discharge valve is configured for opening to allow refrigerant out of the cylinder through the first and second discharge ports. The suction valve can include an aperture for the flow through of refrigerant.

In another exemplary embodiment, the present invention provides a valve mechanism for a refrigerant compressor. The compressor has a cylinder defining an opening along one end. The valve mechanism includes a suction valve plate for positioning at the opening of the cylinder. The suction valve plate includes a first discharge port configured for the discharge of refrigerant from the cylinder; a second discharge port configured for the discharge of refrigerant from the cylinder; and a suction valve located proximate to a suction port and configured for opening under suction to allow refrigerant through the suction port and into the cylinder. The suction valve can include an aperture for the flow through of refrigerant.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 provides an exemplary embodiment of a refrigerator appliance as may be used with the present invention.

FIG. 2 is a schematic of an exemplary refrigeration cycle as may be used with the present invention.

FIG. 3 is an exploded view of a refrigerant compressor having conventional valve plates as will be further described below.

FIG. 4 illustrates an exemplary suction valve plate of the present invention as may be used with the exemplary refrigerant compressor shown in FIG. 3.

FIG. 5 illustrates another exemplary suction valve plate of the present invention as may be used with the exemplary refrigerant compressor shown in FIG. 3.

FIG. 6 is a perspective view of the inlet from a suction muffler providing refrigerant through an exemplary suction valve as shown in FIG. 5. Also shown is a piston of the refrigerant compressor.

FIG. 7 is a cross-sectional view of FIG. 6 taken along lines 7-7. However, a cylinder, rather than its piston, is shown in FIG. 7.

The use of similar or identical reference numerals in the figures represents similar or identical features unless otherwise indicated.

DETAILED DESCRIPTION

The present invention relates to suction and discharge mechanisms for the compressor of a refrigeration cycle. More specifically, the present invention can provide two or more discharge ports for the removal of refrigerant from a compressor as opposed to the one port used in conventional compressors. Additionally, the present invention can provide a suction valve having an aperture for the flow of refrigerant around and through the suction valve when it is in an open position. As such, the present invention can provide a refrigerant compressor having an improved coefficient of discharge and, therefore, increased efficiency. In addition, compressor efficiency in conventional art is further affected by an undesired phenomenon called flutter in the suction and discharge valves. Flutter is primarily affected by valve stiffness and damping owing to the valve shape, material, thickness, valve connection to valve plate, and other factors. These properties can be improved to reduce or eliminate the flutter. In certain exemplary embodiments of the present invention, the opening in the suction valve helps reduce the mass and alters the stiffness and the damping properties both due to material and fluid flow through the valve. Also, in certain exemplary embodiments, the multiple discharge ports and valves help reduce the flow area per port and hence results in smaller discharge valves with smaller mass.

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

FIG. 1 provides a front view of a representative refrigerator 10 in an exemplary embodiment of the present invention. More specifically, for illustrative purposes, the present invention is described with a refrigerator 10 having a construction as shown and described further below. As used herein, a refrigerator includes appliances such as a freezer, refrigerator/freezer combination, compact, and any other style or model of a refrigerator. Accordingly, other configurations including multiple and different styled compartments could be used with refrigerator 10, it being understood that the configuration shown in FIG. 1 is by way of example only. Additionally, the refrigerant compressor of the present invention is not limited to use with a refrigerator appliance and may be used with other appliances as well including e.g., a heat pump dryer.

Refrigerator 10 includes a fresh food storage compartment 12 and a freezer storage compartment 14. Freezer compartment 14 and fresh food compartment 12 are arranged side-by-side within an outer case 16 and defined by inner liners 18 and 20 therein. A space between case 16 and liners 18 and 20, and between liners 18 and 20, is filled with foamed-in-place insulation. Outer case 16 normally is formed by folding a sheet of a suitable material, such as pre-painted steel, into an inverted U-shape to form the top and side walls of case 16. A bottom wall of case 16 normally is formed separately and attached to the case side walls and to a bottom frame that provides support for refrigerator 10. Inner liners 18 and 20 are molded from a suitable plastic material to form freezer compartment 14 and fresh food compartment 12, respectively. Alternatively, liners 18, 20 may be formed by bending and welding a sheet of a suitable metal, such as steel. The illustrative embodiment includes two separate liners 18, 20 as it is a relatively large capacity unit and separate liners add strength and are easier to maintain within manufacturing tolerances. In smaller refrigerators, a single liner is formed and a mullion 24 spans between opposite sides of the liner to divide it into a freezer compartment and a fresh food compartment.

A breaker strip 22 extends between a case front flange and outer front edges of liners 18, 20. Breaker strip 22 is formed from a suitable resilient material, such as an extruded acrylo-butadiene-styrene based material (commonly referred to as ABS). The insulation in the space between liners 18, 20 is covered by another strip of suitable resilient material, which also commonly is referred to as a mullion 24. In one embodiment, mullion 24 is formed of an extruded ABS material. Breaker strip 22 and mullion 24 form a front face, and extend completely around inner peripheral edges of case 16 and vertically between liners 18, 20. Mullion 24, insulation between compartments, and a spaced wall of liners separating compartments, sometimes are collectively referred to herein as a center mullion wall 26. In addition, refrigerator 10 includes shelves 28 and slide-out storage drawers 30, sometimes referred to as storage pans, which normally are provided in fresh food compartment 12 to support items being stored therein.

Refrigerator 10 can be controlled by a microprocessor (not shown) or other processing device according to user preference via manipulation of a control interface 32 mounted in an upper region of fresh food storage compartment 12 and coupled to the microprocessor. A shelf 34 and wire baskets 36 are also provided in freezer compartment 14. In addition, an ice maker 38 may be provided in freezer compartment 14.

A freezer door 42 and a fresh food door 44 close access openings to freezer and fresh food compartments 14, 12, respectively. Each door 42, 44 is mounted to rotate about its outer vertical edge between an open position, as shown in FIG. 1, and a closed position (not shown) closing the associated storage compartment. Freezer door 42 includes a plurality of storage shelves 46, and fresh food door 44 includes a plurality of storage shelves 48.

Refrigerator 10 includes a machinery compartment that incorporates at least part of a refrigeration cycle 50 as shown in FIG. 2. The components of refrigeration cycle 50 include a refrigerant compressor unit 52, a condenser 54, valves 56 and 58, and an evaporator 60—all connected in series and charged with a refrigerant. Evaporator 60 is also a type of heat exchanger that transfers heat from air passing over the evaporator 60 to a refrigerant flowing through evaporator 60, thereby causing the refrigerant to vaporize. As such, cooled air is produced and configured to refrigerate compartments 12, 14 of refrigerator 10.

From evaporator 60, vaporized refrigerant flows to compressor unit 52, which increases the pressure of the refrigerant. This compression of the refrigerant raises its temperature, which is subsequently lowered by passing the gaseous refrigerant through condenser 54 where heat exchange with ambient air takes place so as to cool the refrigerant. Valves 56 and 58 further reduce the pressure of refrigerant leaving condenser 54 before being fed as a liquid to evaporator 60. The refrigeration cycle 50 depicted in FIG. 2 is provided by way of example only. It is within the scope of the present invention for other configurations of the refrigeration system 50 to be used as well.

FIG. 3 provides an exploded view of an exemplary embodiment of a refrigerant compressor 52. The present invention is not limited to use with the compressor shown in FIG. 3 as other configurations for the compressor may be used as well. As shown, compressor 52 includes a suction muffler 100 (to help reduce noise emissions from the intake of refrigerant) that is connected to head cover 105. A head gasket 110 is positioned between head cover 105 and a discharge valve plate 115.

Discharge valve plate 115 has a suction port 150 for the flow of refrigerant into cylinder 135 through an opening 136 at the end of cylinder 135. Discharge valve plate 115 also includes a discharge valve 145 that controls the discharge of refrigerant from cylinder 135 though a discharge port 155 located in suction valve plate 120. Discharge valve 145 is constructed from a metal reed that includes a plate portion 146 that closes (i.e. blocks) discharge port 155 when valve 145 is in a closed position. Typically, discharge valve 145 is assisted by a compression spring (not shown). Accordingly, when a piston (not shown) in cylinder 135 compresses refrigerant by decreasing the volume available, eventually the pressure increases and overcomes discharge valve 145 and its associated compression spring so as to move discharge valve 145 into an open position and allow the discharge of refrigerant from cylinder 135 through discharge port 155.

Discharge valve plate 115 is connected to suction valve plate 120. For purposes of explaining differences between the present invention and conventional compressor units, suction valve plate 120 is shown with a conventional suction valve 190 and a single discharge port 155. Typically, suction valve 190 is constructed from a metal reed that includes a plate portion 192 that closes or blocks the flow of refrigerant through suction port 150 when in the closed position.

When a piston (not shown) in cylinder 135 draws a suction by increasing the volume available in cylinder 135, the vacuum eventually overcomes suction valve 190 (and any associated spring) so that valve 190 moves to an open position whereby refrigerant is allowed through suction port 150, around plate portion 192 of valve 190, through opening 136, and into cylinder 135 where the refrigerant will be subsequently compressed to discharge as described above. Suction valve plate 120 is sealed with compressor pump 140 by gasket 125. A plurality of mounting apertures 101 are shown in each of the parts described above whereby fasteners (e.g., threaded bolts) may be used to connect the same to pump unit 140.

FIG. 4 provides an exemplary embodiment of a suction valve plate 220 of the present invention. Plate 220 includes mounting apertures 201 whereby plate 220 may be substituted for the conventional plate 120 shown with the compressor unit 52 of FIG. 3. Unlike suction valve plate 120 of FIG. 3, however, suction valve plate 220 includes two discharge ports. More specifically, plate 220 includes a first discharge port 255 and a second discharge port 256. As such, compared to plate 120, suction valve plate 220 can increase (e.g., double) the cross-sectional area available for the discharge of refrigerant from cylinder 135. Such increased discharge space provides for decreased pressure drop and improves the coefficient of discharge of the compressor 52, increases its volumetric efficiency, and provides higher energy efficiency as compared to plate 120. A single discharge valve 145 may be used for both first and second discharge ports 255 and 256. Alternatively, discharge valve plate 115 may be equipped with separate discharge valves for each of ports 255 and 256.

The present invention is not limited to only two discharge ports 255 and 256 as shown in FIG. 4. Additional ports may be also be utilized depending upon, e.g., the structural strength of the material used for the construction of suction valve plate 220. Furthermore, although shown as two, equally-sized circular ports 255 and 256 located on both sides of a suction valve 290, other configurations, shapes and sizes may be used as well.

FIG. 5 illustrates another exemplary embodiment of a suction valve plate 320 of the present invention. Plate 320 includes mounting apertures 301 whereby plate 320 may be substituted for conventional plate 120 shown with the compressor 52 of FIG. 3. Like the suction valve plate 120 of FIG. 3, plate 320 includes a single discharge port 355 along one side of a suction valve 390. However, unlike plate 120, suction valve plate 320 includes an aperture 391 in suction valve 320 whereby refrigerant may flow through suction valve 320, in addition to the conventional path around the suction valve, when it is in an open position to allow refrigerant into cylinder 135. As shown in FIG. 5, suction valve 390 includes a plate portion 392 and a stem portion 363. Plate portion 392 blocks suction port 150 when suction valve 390 is in a closed position. However, when in an open position, refrigerant can flow through aperture 391 as well as around suction valve 390 so as to provide improved efficiency.

More specifically, and by way of further description, FIGS. 6 and 7 provide an illustration of the flow of refrigerant (arrows I) through the inlet 370 of suction muffler 100, through suction port 150, and into cylinder 135. Refrigerant is drawn into cylinder 135 when piston 130 moves in the direction of arrow D so as to reduce the pressure by expanding the space available for refrigerant in cylinder 135. As refrigerant flows into cylinder 135, refrigerant can flow both around suction valve 390 (arrow A) as well as through aperture 391 (arrow T) when valve 390 is in an open position. Note that with suction valve 190, refrigerant can only flow around and not through valve 190. Accordingly, suction valve 390 increases the cross-sectional area available for the suction of refrigerant into cylinder 135. Such increased suction capability can provide for a decreased pressure drop due to lower friction losses and better streamlined flow to improve the coefficient of discharge of the compressor 52, increase its volumetric efficiency, and provide a higher energy efficiency as compared to suction valve plate 120.

As with plate 220, the present invention is not limited to suction valve plate 320 having a valve 390 and aperture 391 shaped and positioned only as shown in FIG. 6. Other configurations and shapes may be used as well.

Additionally, for purposes of clarity in describing the present invention, two suction plates 220 and 320 have been shown separately. However, using the teachings disclosed herein, it will be understood by one of skill in the art that a suction valve plate having both an improved suction valve 390 (with aperture 391) as well as multiple discharge ports 255 and 256 may be provided as well.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.