CA2881255A1 - Compressor with magnetically actuated valve assembly - Google Patents

Abstract

A compressor including a housing, a cylinder, and a piston is presented. The cylinder and the piston define a compression chamber, a discharge chamber, and a suction chamber. The compressor further includes at least one valve assembly including a valve member disposed in the housing, wherein the compression chamber is in fluid communication with the discharge chamber or the suction chamber via the valve assembly. The compressor further includes at least one magnetic valve actuation element disposed in the housing, wherein at least one of the magnetic valve actuation element and the valve assembly includes an electromagnet, the electromagnet configured to magnetically actuate the valve member in response to an actuation signal.

Description

COMPRESSOR WITH MAGNETICALLY
ACTUATED VALVE ASSEMBLY
BACKGROUND OF THE INVENTION
[0001] The invention relates generally to compressors with magnetically actuated valve assembly. More particularly, the invention relates to compressors for refrigerators with magnetically actuated valve assembly.

[0002] Valves having different operating principles may be used in compressors.
Reed valve is an example of a valve assembly typically used in small compressors for air condition systems or refrigerators. A typical reed valve includes a reed valve plate (which is usually a thin metal sheet) that is clamped on one side, and is free on the other side. Due to a gas pressure difference differential between inlet and outlet side of the reed valve, it bends upwards to release the overpressure.

[0003] Valve dynamics may govern part of the pressure losses for a compressor eventually determining the efficiency, usually determined by the effective efficiency ratio (EER). Late closure or early opening of the valve may cause a deviation from the ideal compression-expansion cycle, which may lead to extra work input and lower EER.

Further, due to a spring interaction of the reed valve plate and the gas, the valve plate may oscillate during the opening and closing of the valve, which in turn could lead to increased collision of the valve reed with the valve plate or valve stop.
These oscillations may cause noise, material fatigue (leading to reduced valve life), and increased flow losses. Furthermore, part load operation may only be realized in a typical compressor, by using a bypass or reduction of compressor motor speed.

[0004] Thus, there is a need for improved valve assembly configurations for compressors. Further, there is a need for improved valve assembly configurations for compressors used in refrigerators.

BRIEF DESCRIPTION OF THE INVENTION

[0005] One embodiment is directed to a compressor including a housing, a cylinder disposed in the housing, and a piston disposed in the housing. The cylinder and the piston define a compression chamber, a discharge chamber, and a suction chamber.
The compressor further includes at least one valve assembly including a valve member disposed in the housing, wherein the compression chamber is in fluid communication with the discharge chamber or the suction chamber via the valve assembly. The compressor further includes at least one magnetic valve actuation element disposed in the housing, wherein at least one of the magnetic valve actuation element and the valve assembly includes an electromagnet, the electromagnet configured to magnetically actuate the valve member in response to an actuation signal.

[0006] Another embodiment of the invention is directed to a compressor including a housing, a cylinder disposed in the housing, and a piston disposed in the housing. The cylinder and the piston define a compression chamber, a discharge chamber, and a suction chamber. The compressor includes at least one valve assembly including a valve member disposed in the housing, wherein the compression chamber is in fluid communication with the discharge chamber or the suction chamber via the valve assembly. The valve assembly includes a ferromagnetic material disposed on a surface of the valve member, a permanent magnet disposed on a surface of the valve member, or combinations thereof. The compressor further includes at least one electromagnet disposed in the housing such that the electromagnet is configured to actuate the valve member in response to an actuation signal.

[0007] Another embodiment of the invention is directed to a compressor including a housing, a cylinder disposed in the housing, and a piston disposed in the housing. The piston further includes at least one magnetic element. The cylinder and the piston define a compression chamber, a discharge chamber, and a suction chamber. The compressor includes at least one valve assembly including a valve member disposed in the housing, wherein the compression chamber is in fluid communication with the discharge chamber or the suction chamber via the valve assembly, wherein the valve assembly includes an electromagnet configured to actuate the valve member in response to an actuation signal.
DRAWINGS

[0008] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings, in which like characters represent like parts throughout the drawings, wherein:

[0009] FIG. 1 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0010] FIG. 2 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0011] FIG. 3 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0012] FIG. 4 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0013] FIG. 5 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0014] FIG. 6 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0015] FIG. 7 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0016] FIG. 8 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0017] FIG. 9 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0018] FIG. 10 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0019] FIG. 11 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0020] FIG. 12 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0021] FIG. 13 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0022] FIG. 14 illustrates a cross-section view of a compressor, according to an embodiment of the invention;

[0023] FIG. 15 illustrates a refrigerator including the compressor, according to an embodiment of the invention.

[0024] FIG. 16 shows the flux density in reed valve and solenoid from magnetic flux simulation using finite elements;

[0025] FIG. 17 shows a plot of magnetic force versus distance between reed valve and electromagnet; and

[0026] FIG. 18 shows the plot of pressure versus volume for one compression cycle.
DETAILED DESCRIPTION

[0027] Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related.
Accordingly, a value modified by a term or terms, such as "about", and "substantially" is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

[0028] In the following specification and the claims, the singular forms "a", "an"
and 'the" include plural referents unless the context clearly dictates otherwise. As used herein, the term "or" is not meant to be exclusive and refers to at least one of the referenced components being present and includes instances in which a combination of the referenced components may be present, unless the context clearly dictates otherwise.

[0029] As used herein, the terms "may" and "may be" indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and/or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb.
Accordingly, usage of "may" and "may be" indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, while taking into account that in some circumstances, the modified term may sometimes not be appropriate, capable, or suitable.

[0030] In some embodiments, a compressor is presented. The term "compressor"
as used herein refers to a mechanical device that increases the pressure of a fluid by reducing its volume. In some embodiments, the compressor as described herein may be configured to operate an air conditioning system, a refrigeration system, a cooling system, or combinations thereof. In certain embodiments, the compressor as described herein is configured to operate a refrigerator, and the fluid worked upon by the compressor is a refrigerant.

[0031] The compressor may be further classified as a reciprocating compressor, a linear compressor, rotary compressor, a scroll compressor, and the like, according to the mechanism used for compressing the fluid (e.g., a refrigerant). Some embodiments of the invention present a reciprocating compressor having the magnetically actuated valve assembly described herein. Some other embodiments of the present invention present a linear compressor having the magnetically actuated valve assembly described herein.

[0032] Figures 1-10 illustrate representative cross-sectional views of the compressor 100, in accordance with some embodiments of the invention. As indicated in Figures 1-10, the compressor 100 includes a housing 110. The compressor 100 further includes a cylinder 120 and a piston 130 disposed in the housing 110. As shown in Figures 1-10, the cylinder 120 and the piston 130 define a compression chamber 111, a discharge chamber 112, and a suction chamber 113.

[0033] As mentioned earlier, the compressor 100 in accordance with some embodiments of the invention may be a reciprocating compressor or a linear compressor.
Figures 1-6 illustrate embodiments for a reciprocating compressor 100, whereas Figures 7-10 illustrate embodiments for a linear compressor 100. In a reciprocating compressor 100, as shown in Fig. 1, the piston 130 and the cylinder 120 define the compression chamber 111, the discharge chamber 112, and the suction chamber 113, such that the fluid (e.g., the refrigerant) flows in (shown by arrows) from the suction chamber 113 to the compression chamber 111, where it is compressed by the piston 130, and flows out from the compression chamber 111 to the discharge chamber 112 (shown by arrows).
Similarly, in a linear compressor 100, the piston 130 and the cylinder 120 define the compression chamber 111, the discharge chamber 112, and the suction chamber 113, as shown in Fig. 7. However, in one example embodiment of a linear compressor 100, the suction chamber 113 is present in the piston 130, and the fluid (e.g., the refrigerant) flows in (shown by arrows) from the suction chamber 113 (present in the piston 130) to the compression chamber 111, where it is compressed by the piston 130, and flows out from the compression chamber 111 to the discharge chamber 112 (shown by arrows). In some embodiment, a configuration of the suction chamber in the compressor may be similar to the reciprocating compressor.

[0034] With continued reference to Figures 1 and 7, the compressor 100 further includes at least one suction port 114 and a discharge port 115. The suction port 114 allows for the fluid to enter the compression chamber 111 from the suction chamber 113, and the discharge port 115 allows for the exit of the fluid from the compression chamber 111 to the discharge chamber 112. Typically, both suction port 114 and the discharge port 115 are opened and closed using valve assemblies (such, as reed valves) that are actuated by the pressure differential across the two chambers. However, as alluded to previously, conventional valve assemblies may not open or close in time, thus resulting in efficiency loss. Further, valve plate may oscillate (or flutter) during the opening and closing of the valve, which in turn could lead to noise, material fatigue (leading to reduced valve life), and increased losses.

[0035] Embodiments of the invention described herein address the noted shortcomings of the state of the art. According to some embodiments of the invention, the compressor 100 further includes at least one valve assembly 140 disposed in the housing 110, as indicated in Figures 1-10. The compression chamber 111 is in fluid communication with the suction chamber 113 or the discharge chamber 112 via the valve assembly 140. The term "fluid communication" as used herein means that a fluid can flow from the compression chamber 111 to the discharge chamber 112 or the suction chamber 113, via the valve assembly 140. Accordingly, the valve assembly 140 may be configured to open/close the suction port 114 (Figures 2, 3, 6, 9, and 10) or the discharge port 115 (Figures 1, 4, 5, 7, and 8). The valve assembly 140 configured to open/close the suction port may be sometimes referred to as the "suction valve" in the text.
Similarly, the valve assembly 140 configured to open/close the discharge port may be sometimes referred to as the "discharge valve" in the text.

[0036] It should be noted that Figures 1-10, for the sake of representation and brevity, indicate only a single valve assembly (on the discharge or the suction side) that is magnetically actuated. However, as will be apparent to one of ordinary skill in the art, the compressor 100 in operation would include at least one additional valve assembly (not shown), which may or may not be magnetically actuated, in accordance with embodiments of the invention. Figures 12 and 14 illustrate embodiments of the invention (described in detail later) in which both the suction and the discharge valve assemblies are magnetically actuated.

[0037] Referring again to Figures 1-10, the valve assembly 140 includes a valve member 142. In some embodiments, the valve assembly 140 may be a reed valve, and the valve member 142 may be a reed plate or a reed. The valve member 142 may include any suitable material and in some embodiments may be in the form of a thin plate.

[0038] With continued reference to Figures 1-10, the compressor 100 further includes at least one magnetic valve actuation element 150 disposed in the housing 110.
The term "magnetic valve actuation element" as used herein refers to an element including a ferromagnetic material or a magnet. The magnet may further include an electromagnet or a permanent magnet. A suitable configuration of the magnetic valve actuation element 150 may be chosen depending, in part, on one or both of the location of the magnetic valve actuation element 150 and the valve assembly 140 type.

[0039] In some embodiments, the magnetic valve actuation element 150 is disposed in the housing 110 such that the magnetic valve actuation element 150 is proximate to the valve assembly 140 during operation of the compressor 100, in particular during the compression cycle when the valve assembly 140 needs to be actuated. In* some embodiments, as shown in Figures 1-3, 7 and 9, the magnetic valve actuation element 150 is disposed in the suction chamber 113 or the discharge chamber 112. In some such embodiments, the magnetic valve actuation element 150 may be attached to one more of the interior surface of the housing 110, the interior surface of the cylinder 120, and the cylinder head. In some other embodiments, as shown in Figures 4-6, 8 and 10, the piston 130 may include the magnetic valve actuation element 150, and the magnetic valve actuation element 150 may be disposed on a surface of the piston head or embedded inside the piston itself.

[0040] As mentioned previously, embodiments of the invention present magnetically actuated valve assemblies for compressor. Accordingly, at least one of the magnetic valve actuation element 150 and the valve assembly 140 includes an electromagnet; the electromagnet is configured to magnetically actuate the valve member 142 in response to an actuation signal. A suitable electromagnet may include a solenoid core and a coil of a conductive material (e.g., copper). Non-limiting examples of suitable solenoid configurations may include E-shaped, round shaped, or rectangular shaped core.
In certain embodiments, a suitable solenoid configuration may include an E-shaped core.

[0041] The term "magnetically actuate" as used herein means that in response to an actuation signal a magnetic force is initiated or terminated between the magnetic valve actuation element 150 and the valve assembly 140, such the valve member 142 is actuated. The terms "actuated" and "actuation" as used herein include initiating or assisting in opening/closing of the valve member 142. Further, the term "actuated" also includes keeping the valve member 142 open/closed for the desired period of time. As mentioned earlier, a valve member 142 is actuated in a typical compressor based on the pressure differential across the clambers. As will be apparent to one of ordinary skill in the art, in the embodiments described herein, the valve member 142 is magnetically actuated in conjunction with the pressure differential across the chambers.

[0042] In some embodiments, the compressor 100 may further include one or more controllers and sensors (not shown). The sensor may be configured to determine one or more of the location of the valve member 142, the location of the piston 130, the gas pressure in the compression chamber 111, the gas pressure in the discharge chamber 112, and the gas pressure in the suction chamber 113. The sensor may be further configured to send an actuation signal to the controller such that an intensity and/or direction of the current applied to the electromagnet is altered, thereby actuating the valve member 142.

[0043] According to one embodiment of the invention, the magnetic valve actuation element 150 may be disrmsed in the suction chamber 113 or the discharge chamber 112, as shown in Figures 1-3, 7 and 9. In some such embodiments, the magnetic valve actuation element 150 includes an electromagnet, as shown in Figures 1-3, 7 and 9. Further, in such embodiments, wherein the magnetic valve actuation element 150 includes an electromagnet, the valve assembly 140 includes a ferromagnetic material 144 disposed on a surface of the valve member 142, a permanent magnet 144 disposed on a surface of the valve member 142, or another electromagnet.

[0044] In certain embodiments, the valve assembly 140 includes a ferromagnetic material 144 disposed on a surface of the valve member 142, a permanent magnet disposed on a surface of the valve member 142, or combinations thereof. This is in contrast to a valve assembly including a valve plate (or a reed) that is itself ferromagnetic. In such instances, the thin valve plate (or reed) may quickly get magnetically saturated and may not generate sufficient magnetic force to actuate the reed.
Thicker valve plate (or reed) on the other hand may not have the desired resilience or flexibility to bend in response to the gas pressure across the chamber.
Some embodiments of the invention address the noted shortcomings of the art by including an additional layer of a ferromagnetic material or a permanent magnet 144 disposed on a surface of the valve member 142, as indicated in Figures 1-3, 7, and 9.

[0045] In some embodiments, the valve member 142 has a thickness in a range from about 0.05 millimeters to about 0.35 millimeters. The thickness of the ferromagnetic material or permanent magnet may be chosen to achieve the desired magnetic flux without significantly effective the resilience of the valve member 142. A
suitable thickness of the ferromagnetic material or the permanent magnet may be in a range from about 0.1 millimeters to about 0.5 millimeters, in some embodiments. Non-limiting examples of suitable ferromagnetic materials may include iron, iron alloys, ferrite, nickel, or combinations thereof. The ferromagnetic material or the permanent magnet 144 may be disposed on a portion of the surface of the valve member 142 or may substantially cover the surface of the valve member 142. Further, in some embodiments, it may be desirable that the ferromagnetic material or the permanent magnet is disposed on a surface of the valve member 142 that is facing the magnetic valve actuation element 150.

[0046] In some embodiments, both the magnetic valve actuation element 150 and the valve assembly 140 may include electromagnets (not shown in Figures). In such instances, one or both of the magnetic valve actuation element 150 and the valve assembly 140 may be configured to receive an actuation signal to actuate the valve member 142. In some embodiments, an electromagnet may be arranged around the valve member 142, or alternatively, in some other embodiments, the valve member 142 itself may be an electromagnet.

[0047] In some embodiments, the magnetic valve actuation element 150 may be configured to receive an activation signal when the valve member 142 is at a determined position relative to the magnetic valve actuation element 150, thereby generating an attractive or a repulsive magnetic force such that the valve assembly 140 is opened.
Referring again to Figures 1, 3 and 7, in order to open the discharge or suction valve assembly 140, an attractive magnetic force may be generated between the magnetic valve actuation element 150 and the valve assembly 140, such that the opening of the valve assembly 140 is assisted along with the pressure differential generated across the chambers. Similarly, in Figures 2 and 9, in order to open the suction valve assembly 140, a repulsive magnetic force may be generated between the magnetic valve actuation element 150 and the valve assembly 140.

[0048] In some other embodiments, the opening of the valve assembly 140 may be primarily effected using the pressure differential across the chambers and the magnetic valve actuation element 150 may be employed to keep the valve assembly 140 open such that the fluttering of the valve assembly 140 is minimized. In some such embodiments, the magnetic valve actuation element 150 may be configured to receive an activation signal when the valve member 140 is in contact with the magnetic valve actuation =

element 140, thereby generating an attractive magnetic force such that the valve assembly 140 is kept open.

[0049] In some embodiments, the magnetic valve actuation element 150 may be configured to receive an activation signal when a gas pressure in the compression chamber reaches a determined value, thereby generating an attractive magnetic force, generating a repulsive magnetic force, or deactivating the magnetic force, such that the valve assembly 140 is closed. Referring again to Figures 1, 3 and 7, in some embodiments, in order to close the discharge or suction valve assembly 140, a repulsive magnetic force may be generated between the magnetic valve actuation element 150 and the valve assembly 140, such that the closing of the valve assembly 140 is assisted along with the pressure differential generated across the chambers. Similarly, in Figures 2 and 9, in order to close the suction valve assembly 140, an attractive magnetic force may be generated between the magnetic valve actuation element 150 and the valve assembly 140.

[0050] In some other embodiments, in order to close the discharge or suction valve assembly 140, the electrical current to the magnetic valve actuation element 150 may be turned off to deactivate the magnetic force between the magnetic valve actuation element 150 and the valve assembly 140, such that the closing of the valve assembly 140 is assisted, along with the spring force.

[0051] Thus by way of example, the valve member (e.g., reed) 142 in Fig. 1 may open because of overpressure at the compression chamber 111 side. As the valve member 142 gets closer to or is in contact with the magnetic valve actuation element 150, an actuation signal may be sent by the sensor to a controller, such that the magnetic valve actuation element (e.g., solenoid) 150 may get powered to generate an attractive force, and the valve assembly 140 is kept open to allow the fluid to pass through it.
Once, the gas pressure in the compression chamber 111 and the discharge chamber 112 is substantially the same, a sensor may send a deactivation signal, such that the magnetic valve actuation element 150 is unpowered and the valve member 142 is closed because of the spring force.

[0052] According to some embodiments of the invention, the magnetic circuit of the electromagnet (e.g., solenoid) may be closed when the valve member 142 is at its maximum stroke position, which results in strong magnetic forces and the valve member 142 is fixed in an open position. This "clamping" or "fixing" of the valve member 142 to the electromagnet (e.g., solenoid) may avoid oscillations during the opening phase.
Further, using this configuration, the valve member 142 closing time may be shifted to a later point (by generating the appropriate repulsive or attractive magnetic force), thus enabling part load operation of the compressor.

[0053] In some other embodiments, the valve assembly 140 may include the electromagnet configured to actuate the valve member 142, and the magnetic valve actuation element 150 may include a ferromagnetic material, a permanent magnet, or another electromagnet. In such embodiments, when the valve member 142 is at a determined position relative to the magnetic valve actuation element 150, a sensor may send an activation signal to the controller, thereby generating an attractive magnetic force such that the valve assembly is opened. Further, in such embodiments, when a gas pressure in the compression chamber 111 reaches a determined value, a sensor may send a deactivation signal to the controller, thereby generating a repulsive magnetic force, or deactivating the magnetic force, such that the valve assembly 140 is closed.

[0054] According to another embodiment of the invention, the piston 130 includes the magnetic valve actuation element 150, as shown in Figures 4-6, 8, and 10.
The magnetic valve actuation element 150 in such embodiments may be disposed on a surface of the piston head (Figures 5 and 6) or disposed inside the piston itself (Figures 4, 8 and 10). In some other embodiments, the magnetic valve actuation element 150 may be attached or fixed to the piston 130 (embodiment not shown).

[0055] In some such embodiments, the valve assembly 140 includes an electromagnet and the magnetic valve actuation element 150 includes a permanent magnet or a ferromagnetic material, as shown in Figures 4-6, 8 and 10. As noted earlier, the electromagnet is configured to actuate the valve assembly 140 in response to an actuation signal. In some embodiments, an electromagnet may be arranged around the valve member 142, or alternatively, in some other embodiments, the valve member 142 itself may be an electromagnet.

[0056] In some embodiments, the electromagnet in the valve assembly 140 may be configured to actuate the valve member 142 when the piston 130 is at a determined position relative to valve assembly 140, thereby generating an attractive or a repulsive magnetic force such that the valve assembly 140 is opened. Referring again to Figures 4-5, 8 and 10 in order to open the discharge or suction valve assembly 140, a repulsive magnetic force may be generated between the magnetic valve actuation element 150 and the valve assembly 140, such that the opening of the valve assembly 140 is assisted along with the pressure differential generated across the chambers. Similarly, in Fig. 6, in order to open the suction valve assembly 140, an attractive force may be generated between the magnetic valve actuation element 150 and the valve assembly 140.

[0057] In some embodiments, the electromagnet in the valve assembly 140 may be configured to actuate the valve member 142 when the piston 130 is at a determined position relative to valve assembly 140, thereby generating an attractive or a repulsive magnetic force such that the valve assembly 140 is closed. Referring again to Figures 4-5, 8 and 10 in order to close the discharge or suction valve assembly 140, an attractive magnetic force may be generated between the magnetic valve actuation element 150 and the valve assembly 140, such that the closing of the valve assembly 140 is assisted along with the pressure differential generated across the chambers. Similarly, in Fig. 6, in order to close the suction valve assembly 140, a repulsive force may be generated between the magnetic valve actuation element 150 and the valve assembly 140.

[0058] In some other embodiments, in order to close the discharge or suction valve assembly 140, the electrical current to the electromagnet in the valve assembly 140 may be turned off to deactivate the magnetic force between the magnetic valve actuation element 150 and the valve assembly 140, such that the closing of the valve assembly 140 is assisted, along with the spring force.

[0059] Thus, by way of example, and with reference to the discharge valve assembly 140 in Fig. 5, a switching of the magnetic force between the magnetic valve actuation element 150 and the valve assembly 140 is described to magnetically actuate the valve assembly 140. In Fig. 5, as the piston gets closer to the valve assembly 140 (that is approaches top dead center (TDC)), in response to a sensor, an activation signal may be sent to a controller, such that a repulsive magnetic force is generated between the magnetic valve actuation element 150 and the valve assembly 140. This repulsive magnetic force along with the pressure differential between the compression chamber 111 and the discharge chamber 112 may assist in rapid opening of the valve. At a particular distance of the piston 130, in response to a sensor, a deactivation signal may be sent to a controller, such that the magnetic force switches to an attractive force (e.g., by changing the current direction to the electromagnet), and counteracts the pressure differential, thereby keeping the valve open at a fixed position. As the distance between the piston 130 and the valve assembly 140 goes on decreasing, this magnetic force increases and enables closure of the valve assembly 140 when the piston 130 reaches the TDC.

[0060] Similarly, with reference to the suction valve assembly 140 as shown in Fig. 6, as the piston move away from the valve assembly 140, in response to a sensor, an activation signal may be sent to a controller, such that an attractive magnetic force is generated between the magnetic valve actuation element 150 and the valve assembly 140.
This attractive magnetic force along with the pressure differential between the compression chamber 111 and the suction chamber 113 may assist in rapid opening of the valve. As the piston 130 moves closer to the bottom dead center (BDC), in response to a sensor, a deactivation signal may be sent to a controller, such that the magnetic force switches to a repulsive force (e.g., by changing the current direction to the electromagnet), and counteracts the pressure differential, thereby closing the valve.
Thus, by using magnetic valve actuation elements in the piston 130, the valves may open/close at desired crank angle locations (e.g., suction valve at bottom dead center and discharge valve at top dead center). Further, the presence of magnetic force may decrease the maximum lift (thereby decreasing the collision velocity), and flutter frequency of the valve members.

[0061] As alluded to previously, the compressor 100 may include a plurality of valve assemblies, a plurality of magnetic valve actuation elements, or both.
According to one embodiment of the invention, a compressor 100 includes a plurality of magnetic valve actuation elements is presented, as shown in Figures 11 and 13. Fig. 11 illustrates a cross-sectional view of a reciprocating compressor, while Fig. 13 illustrates a cross-sectional view of a linear compressor. In Figures 11 and 13, the compressor 100 includes a first magnetic actuating element 150 disposed in the discharge chamber 112 and a second magnetic actuating element 170, wherein the piston 130 includes the second magnetic actuating element 170. The compressor 100 further includes the valve assembly 140, such that at least one of the first magnetic actuating element 150, the second magnetic actuating element 170, and the valve assembly 140 includes the electromagnet. In the example embodiments illustrated in Figures 11 and 13, the valve member 142 includes the electromagnet. In such embodiments, for example, to effect opening of the valve, an attractive magnetic force may be generated between the valve member 142 and the first magnetic valve actuation element 150, and a repulsive magnetic force may be generated between the valve member 142 and the second magnetic valve actuation element 170. To close the valve, the magnetic force polarities may be reversed.

[0062] In such instances, the actuation of the valve member 142 may be effected by the combined effect of both the magnetic valve actuation elements 150/170, thereby resulting in faster opening/closing of the valves and lesser number of oscillations. The increasing strength of the magnetic force (both repulsive and attractive) as the piston 130 moves closer or further, may result in a faster response of the valve. Thus, by optimizing the magnetic force strength between the valve and the two magnetic valve actuation elements and the timing of magnetic force switching, a compressor configuration having an improved net EER and increased valve life may be obtained.

[0063] According to one embodiment of the invention, a compressor 100 include a plurality of valve assemblies and magnetic valve actuation elements is presented, as shown in Figures 12 and 14. Fig. 12 illustrates a cross-sectional view of a reciprocating compressor while Fig. 14 illustrates a cross-sectional view of a linear compressor. In Figures 12 and 14, the compressor 100 includes a first valve assembly 140 including a first valve member 142 and a second valve assembly 160 including a second valve member 162. As shown in Figures 12 and 14, the compression chamber 111 is in fluid communication with the discharge chamber 112 via the first valve assembly 140, and the compression chamber 111 is in fluid communication with the suction chamber 113 via the second valve assembly 160. The compressor 100 further includes a first magnetic valve actuation element 150 and a second magnetic valve actuation element 170.
At least one of the first magnetic valve actuation element 150 and the first valve assembly 140 includes a first electromagnet, the first electromagnet configured to magnetically actuate the first valve member 142 in response to a first actuation signal, as shown in Figures 12 and 14. Further, at least one of the second magnetic valve actuation element 170 and the second valve assembly 160 includes a second electromagnet, the second electromagnet configured to magnetically actuate the second valve member 162 in response to a second actuation signal. In the example embodiments illustrated in Figures 12 and 14, the second valve member 162 includes the electromagnet. Further, the first valve assembly 140 includes a ferromagnetic material or a permanent magnet 144 disposed on a surface of the valve member 142, and the first magnetic valve actuation element 150 includes the electromagnet. In such instances, the actuation of the both the discharge and suction valves may be effected by magnetic actuation, thereby resulting faster opening/closing of the valves and lesser number of oscillations.

[0064] In some embodiments, a refrigerator unit (e.g., a household refrigerator) including a compressor as described herein is presented. In a refrigerator, a compressor is used to compress a refrigerant. In a household refrigerator, as the refrigerant passes through one or more evaporators (not shown), the refrigerant absorbs heat from one or more refrigerator compartments (not shown) and hence produces a cooling effect. In the evaporator, the refrigerant undergoes an expansion and the expanded refrigerant is compressed in the compressor. Fig. 15 shows a refrigerator unit 200 including one example compressor 100 configuration. A suitable compressor configuration as described herein may be used in the refrigerator 200.

[0065] The compressor configurations as described herein, in accordance with the embodiments of the invention, may provide for one or more of (i) late closure of discharge valve and/or suction valve, (ii) less number of oscillation or flutter frequency, (iii) faster valve response time, (iv) improved valve life, (v) improvement in EER, and (vi) part load operation.
EXPERIMENTAL
Example 1

[0066] Simulation tests were conducted to calculate the magnetic force for a particular reed thickness. Fig. 16 shows the flux density in reed valve (reed thickness 0.3 millimeters) and solenoid from magnetic flux simulation using finite elements. As shown in Fig. 16, the thin reed plate is a bottleneck for flux lines. Thicker plates may show higher magnetic forces but may affect the valve dynamics. Fig. 17 shows the magnetic force generated as function of distance between reed valve and electromagnet.
In the example shown in Fig. 17, a maximum force of 1.33N is generated at a thickness of 0.5 millimeters. Accordingly, in this example, an additional ferromagnetic material (of approximately ¨0.2 mm thickness) may be disposed on the reed to generate the desired magnetic flux. Fig. 18 shows the pressure versus volume for one compression cycle. At least a portion of the losses (shown by hashed region) may be reduced with the magnetically actuated valve, in accordance with some embodiments of the invention.

[0067] The present invention has been described in terms of some specific embodiments. They are intended for illustration only, and should not be construed as being limiting in any way. Thus, it should be understood that modifications can be made thereto, which are within the scope of the invention and the appended claims.

Furthermore, all of the patents, patent applications, articles, and texts which are mentioned above are incorporated herein by reference.

Claims (20)

WHAT IS CLAIMED IS:

1. A compressor, comprising:
a housing;
a cylinder and a piston disposed in the housing, wherein the cylinder and the piston define a compression chamber, a discharge chamber, and a suction chamber;
at least one valve assembly comprising a valve member disposed in the housing, wherein the compression chamber is in fluid communication with the discharge chamber or the suction chamber via the valve assembly; and at least one magnetic valve actuation element disposed in the housing, wherein at least one of the magnetic valve actuation element and the valve assembly comprises an electromagnet, the electromagnet configured to magnetically actuate the valve member in response to an actuation signal.

2. The compressor of claim 1, wherein the magnetic valve actuation element is disposed in the discharge chamber or in the suction chamber.

3. The compressor of claim 2, wherein the magnetic valve actuation element comprises the electromagnet, and the valve assembly comprises a ferromagnetic material disposed on a surface of the valve member, a permanent magnet disposed on a surface of the valve member, or another electromagnet.

4. The compressor of claim 3, wherein a thickness of the ferromagnetic material or the permanent magnet is in a range from about 0.1 millimeters to about 0.5 millimeters.

5. The compressor of claim 3, wherein the magnetic valve actuation element is configured to receive an activation signal when the valve member is at a determined position relative to the magnetic valve actuation element, thereby generating an attractive or a repulsive magnetic force, such that the valve assembly is opened.

6. The compressor of claim 3, wherein the magnetic valve actuation element is configured to receive an activation signal when the valve member is in contact with the magnetic valve actuation element, thereby generating an attractive or a repulsive magnetic force, such that the valve assembly is kept open.

7. The compressor of claim 3, wherein the magnetic valve actuation element is configured to receive a deactivation signal when a gas pressure in the compression chamber reaches a determined value, thereby generating an attractive magnetic force, generating a repulsive magnetic force, or deactivating the magnetic force, such that the valve assembly is closed.

8. The compressor of claim 2, wherein the valve assembly comprises the electromagnet, and the magnetic valve actuation element comprises a ferromagnetic material, a permanent magnet, or another electromagnet.

9. The compressor of claim 8, wherein the valve assembly is configured to receive an activation signal when the valve member is at a determined position relative to the magnetic valve actuation element, thereby generating an attractive magnetic force or a repulsive magnetic force, such that the valve assembly is opened.

10. The compressor of claim 8, wherein the valve assembly is configured to receive a deactivation signal when a gas pressure in the compression chamber reaches a determined value, thereby generating an attractive magnetic force, generating a repulsive magnetic force, or deactivating the magnetic force, such that the valve assembly is closed.

11. The compressor of claim 1, wherein the piston comprises the magnetic valve actuation element.

12. The compressor of claim 11, wherein the valve assembly comprises the electromagnet, and the magnetic valve actuation element comprises a permanent magnet or a ferromagnetic material.

13. The compressor of claim 12, wherein the electromagnet is configured to receive an activation signal when the piston is at a determined position relative to the valve assembly, thereby generating an attractive or a repulsive magnetic force, such that the valve assembly is opened.

14. The compressor of claim 12, wherein the magnetic valve actuation element is configured to receive a deactivation signal when the piston is at a determined position relative to the valve assembly, thereby generating an attractive or a repulsive magnetic force, such that the valve assembly is closed.

15. The compressor of claim 1, comprising a first magnetic actuating element disposed in the housing, and a second magnetic actuating element, wherein the piston comprises the second magnetic actuating element, and wherein at least one of the first magnetic actuating element, the second magnetic actuating element, and the valve assembly comprises the electromagnet.

16. The compressor of claim 1, comprising:
a first valve assembly comprising a first valve member;
a second valve assembly comprising a second valve member;
a first magnetic valve actuation element; and a second magnetic valve actuation element, wherein the compression chamber is in fluid communication with the discharge chamber via the first valve assembly, and the compression chamber is in fluid communication with the suction chamber via the second valve assembly, wherein at least one of the first magnetic valve actuation element and the first valve assembly comprises a first electromagnet, the first electromagnet configured to magnetically actuate the first valve member in response to a first actuation signal, and wherein at least one of the second magnetic valve actuation element and the second valve assembly comprises a second electromagnet, the second electromagnet configured to magnetically actuate the second valve member in response to a second actuation signal.

17. The compressor of claim 1, wherein the compressor is configured to operate an air conditioning system, a refrigeration system, a cooling system, or combinations thereof.

18. A refrigerator comprising the compressor as defined in claim 1.

19. A compressor, comprising:
a housing;
a cylinder and a piston disposed in the housing, wherein the cylinder and the piston define a compression chamber, a discharge chamber, and a suction chamber;
at least one valve assembly comprising a valve member disposed in the housing, wherein the compression chamber is in fluid communication with the discharge chamber or the suction chamber via the valve assembly, and wherein the valve assembly comprises:
a ferromagnetic material disposed on a surface of the valve member, a permanent magnet disposed on a surface of the valve member, or combinations thereof; and at least one electromagnet disposed in the housing such that the electromagnet is configured to actuate the valve member in response to an actuation signal.

20. A compressor, comprising:
a housing;
a cylinder and a piston disposed in the housing, wherein the cylinder and the piston define a compression chamber, a discharge chamber, and a suction chamber, and wherein the piston comprises a magnetic valve actuation element; and at least one valve assembly comprising a valve member disposed in the housing, wherein the compression chamber is in fluid communication with the discharge chamber or the suction chamber via the valve assembly, and wherein the valve assembly comprises an electromagnet configured to actuate the valve member in response to an actuation signal.