Axial flux motor for HVAC&R systems

Abstract

A compression system for heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems includes a compressor configured to guide a working fluid through a vapor compression circuit, and an axial flux motor coupled to the compressor and configured to drive the rotation of the compressor.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority and the benefit thereof from U.S. Provisional Application No. 63 / 471,449, filed on Jun. 6, 2023, entitled “AXIAL FLUX MOTOR FOR HVAC&R SYSTEM”, which is hereby incorporated by reference in its entirety for all purposes.

Background Art

[0002] This section is intended to introduce the reader to various aspects of the technical field that may be related to various aspects of the present disclosure, and aspects of the technical field are described below. This discussion is considered useful in providing the reader with background information to facilitate a deeper understanding of various aspects of the present disclosure. Therefore, it should be understood that these descriptions are to be read from this perspective and should not be read as an endorsement of the prior art.

[0003] Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, or vapor compression systems, are used in residential, commercial, and industrial environments to control environmental characteristics such as temperature and humidity for the occupants of each environment. HVAC&R systems circulate a working fluid (e.g., a refrigerant) that changes phases between vapor, liquid, and combinations thereof in response to being exposed to different temperatures and pressures associated with the operation of the HVAC&R system. For example, an HVAC&R system may include one or more compressors configured to circulate the working fluid through a working fluid circuit, which may include a heat exchanger configured to transfer heat between the working fluid and another fluid (e.g., a cooling fluid) flowing through the heat exchanger. Typically, the compressors are actuated by motors. Some motors include a rotating member that rotates the compressor, thereby enabling the compressor to compress the working fluid and send it to other components of the vapor compression system. Unfortunately, existing motors are susceptible to various inefficiencies, which can reduce the efficiency of HVAC&R systems and / or shorten the useful life of HVAC&R system components. [Overview of the project]

[0004] An overview of certain embodiments disclosed herein is described below. These embodiments are presented solely to provide the reader with a brief overview of these particular embodiments, and it should be understood that they are not intended to limit the scope of this disclosure. In fact, this disclosure may encompass various embodiments not described below.

[0005] In one embodiment, a compression system for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a compressor configured to guide a working fluid through a vapor compression circuit, and an axial flux motor coupled to the compressor and configured to drive the rotation of the compressor.

[0006] In another embodiment, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a compressor configured to guide a working fluid through a vapor compression circuit, a condenser configured to place the working fluid into a first heat exchange relationship, an evaporator configured to place the working fluid into a second heat exchange relationship, and an axial flux motor coupled to the compressor and configured to drive the rotation of the compressor to force the working fluid to flow through the vapor compression circuit.

[0007] In another embodiment, a compression system for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a compressor configured to guide a working fluid through a vapor compression circuit, an axial flux motor coupled to the compressor and configured to drive the rotation of the compressor, and a control device. The axial flux motor includes a first rotor including a first set of magnets, a second rotor including a second set of magnets, and a stator including one or more electromagnets and one or more electric windings arranged around the one or more electromagnets. The control device is configured to activate or deactivate the one or more electromagnets via signals transmitted through the one or more electric windings, thereby rotating the first and second rotors about the axis of rotation of the axial flux motor.

[0008] Various aspects of this disclosure can be better understood by reading the following detailed description and referring to the drawings. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of one embodiment of a building including a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system in a commercial environment, according to one aspect of the present disclosure. [Figure 2] This is a perspective view of one embodiment of a vapor compression system according to one aspect of the present disclosure. [Figure 3] This is a schematic diagram of one embodiment of a vapor compression system according to one aspect of the present disclosure. [Figure 4]This is a schematic diagram of one embodiment of a vapor compression system according to one aspect of the present disclosure. [Figure 5] This is a perspective view of one embodiment of a motor and compressor for an HVAC&R system according to one aspect of the present disclosure. [Figure 6] This is an exploded perspective view of one embodiment of a compressor motor for an HVAC&R system according to one aspect of the present disclosure. [Figure 7] This is a schematic diagram of one embodiment of a motor and compressor for a vapor compression system in an HVAC&R system, according to one aspect of the present disclosure. [Figure 8] This is a schematic diagram of one embodiment of a motor and compressor for a vapor compression system in an HVAC&R system, according to one aspect of the present disclosure. [Modes for carrying out the invention]

[0010] One or more specific embodiments of this disclosure are described below. These embodiments described are examples of the technology of this disclosure. In addition, as part of an effort to provide a concise description of these embodiments, not all features of actual implementations may be described herein. It should be understood that in developing any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made, which may differ from implementation to implementation, in order to achieve developer-specific goals, such as compliance with system-related and industry-related constraints. Furthermore, it should be understood that such development efforts may be complex and time-consuming, but are still considered normal business of design, fabrication, and manufacturing for those skilled in the art who are interested in this disclosure.

[0011] When introducing elements of the various embodiments of this disclosure, the articles “a,” “an,” and “the” are intended to indicate that there is one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be comprehensive and mean that there may be additional elements other than those enumerated. In addition, it should be understood that any reference in this disclosure to “one embodiment” or “an embodiment” is not intended to be interpreted as excluding the existence of additional embodiments that similarly incorporate the enumerated features.

[0012] Where used herein, terms such as “approximately,” “generally,” and “substantially” are intended to convey, as a person skilled in the art would understand, that the described characteristic value may fall within a relatively small range of characteristic values. For example, when a characteristic value is described as “approximately” equal to (or, for example, “substantially similar to”) a given value, it is intended to convey that the characteristic value may be within ±5%, ±4%, ±3%, ±2%, ±1% of the given value, or even closer to the given value. Similarly, when a given feature is described as “substantially parallel” to another feature, or “generally orthogonal” to another feature, it is intended to convey that the given feature is within ±5%, ±4%, ±3%, ±2%, ±1% of having the described property, such as being parallel or orthogonal to another feature, or even closer to it. Furthermore, it should be understood that mathematical terms such as “planar,” “inclined,” “orthogonal,” and “parallel” are intended to encompass surface or element characteristics as understood by those skilled in the art in the relevant field, and should not be interpreted as strictly as they might be understood in the field of mathematics. For example, two components having axes that are “parallel” to each other are intended to encompass the fact that the axes of the components are not mathematically strictly parallel, but rather extend substantially parallel to each other (e.g., within the relevant tolerance range).

[0013] As briefly discussed above, heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) systems may be configured to operate to meet heating and / or cooling needs in buildings, residences, industrial facilities, or other suitable structures. For example, an HVAC&R system may include a vapor compression system (e.g., a chiller system, a heat pump system) that transfers thermal energy between a working fluid (e.g., water, a refrigerant, a heat transfer fluid) and a fluid to be conditioned (e.g., air, water, or brine). A vapor compression system may include one or more vapor compression circuits (e.g., a heat pump) each containing a condenser and an evaporator, which are fluid-coupled to one another via one or more conduits (e.g., a vapor compression circuit, a working fluid circuit, a refrigeration circuit). Furthermore, each vapor compression circuit may include a compressor configured to pressurize and circulate the working fluid through the circuit, thereby enabling the transfer of thermal energy between the working fluid and the fluid to be conditioned via the condenser and / or evaporator. To facilitate different operating modes (e.g., cooling mode, heating mode, standby mode, idling mode), the vapor compression system may include several controllable features or components, such as valves, expansion devices, coil fans, condenser pumps, and / or evaporator pumps. The vapor compression system may include a control device configured to determine the operating mode of the vapor compression system and to control the compressor, valves, expansion devices, pumps, fans, etc., to operate the vapor compression system in the desired mode. In certain embodiments, the vapor compression system may be a heat pump system configured to facilitate the flow of working fluid through the vapor compression circuit in different directions for different operating modes. In other embodiments, the flow of working fluid through the vapor compression circuit may be in the same direction for multiple (e.g., all) operating modes.

[0014] To compress the working fluid, the compressor may be coupled to a motor configured to drive or power the compressor. For example, the motor may include a rotor shaft supported by a bearing assembly within a motor housing. The rotor shaft may be coupled to the compressor shaft, which in turn may be coupled to the compressor's impeller. In some embodiments, the motor may rotate the rotor shaft, thereby enabling rotation of the compressor shaft and impeller, and consequently allowing the compressor to compress the working fluid and drive the flow of the working fluid through the working fluid circuit. However, to sufficiently compress the working fluid to the desired working pressure, the compressor may be configured to operate at high speed. Conventional HVAC&R systems typically employ certain motors, such as radial flux motors, to actuate the compressor.

[0015] Unfortunately, existing motors used in HVAC&R systems (e.g., radial flux motors) can be associated with various inefficiencies, higher operating costs, and a low relative torque-to-weight ratio for operating the compressor, among other drawbacks. For example, a compressor with a radial flux motor may include a gearbox configured to enable the operation of the radial flux motor and / or compressor. A radial flux motor can also generate a magnetic flux path extending along the motor's stator, which is generally located radially outward from the rotor and extends perpendicularly to the axis of rotation of the radial flux motor and / or compressor. In addition, a radial flux motor may include a relatively large number of components configured to operate it. The large number of components may be associated with an increased amount of iron and / or copper in the radial flux motor, which can also result in various inefficiencies. Furthermore, the stator of a radial flux motor may include two ends located on opposite sides of the radial flux motor, and the electrical windings may be oriented around the ends of the radial flux motor (for example, along the circumferential direction). Due to the geometry of the stator in a radial flux motor, the windings may bend around the ends of the stator. However, such bending around the stator can cause electrons flowing through the windings to interfere with each other, which can result in efficiency losses. Efficiency losses can increase as the amount of iron and / or copper in the motor increases. That is, due to the geometry and / or orientation of the stator in a radial flux motor, copper ions and / or iron ions in the components of the radial flux motor may interfere with electrons flowing through the windings, which can result in further efficiency losses. Therefore, existing radial flux motors (for example, those used in compressors in HVAC&R systems) can suffer from various inefficiencies due to increased length of the magnetic flux path, increased amount of copper and / or iron, and / or bending of the electrical windings along the ends of the stator.In addition, radial flux motors may include a gearbox and / or occupy a larger footprint, which may result in increased costs associated with the manufacture of radial flux motors and / or increased space occupied by the HVAC&R system.

[0016] Accordingly, embodiments of the present disclosure apply to HVAC&R systems including a compressor comprising an axial flux motor configured to drive the compressor and enable the flow of working fluid through a vapor compression circuit. For example, embodiments include an axial flux motor having a housing that defines a volume in which the components of the axial flux motor are arranged. The axial flux motor may also include a rotor shaft, a rotor, and a stator having windings arranged around and / or on the stator core (e.g., an iron stator core, around the teeth of the stator core), thereby defining one or more electromagnets of the stator. In some embodiments, the axial flux motor may include two rotors and / or two stators. The stators and rotors are positioned adjacent to each other and axially offset from each other along the central axis of the axial flux motor (e.g., the axis of rotation of the rotors). For example, some embodiments of the axial flux motor may include one stator taken up (e.g., sandwiched) between two rotors. Alternatively, an axial flux motor may include a rotor enclosed (e.g., sandwiched) between two stators. One or more rotors may be coupled to a rotor shaft and may include magnets (e.g., permanent magnets) coupled to it, and may be configured to bias the rotor in a particular direction (e.g., direction of rotation) based on electrical signals (e.g., current) passing through the stator windings. For example, a control device may be configured to transmit electrical signals through the stator windings, thereby acting and / or exciting the stator electromagnets, which in turn cause the rotor magnets to be attracted toward or repelled toward the actuated electromagnets. Furthermore, the rotor shaft of an axial flux motor may be coupled to a compressor shaft, so that the rotation of the rotor shaft rotates the compressor shaft, compressing and / or driving a working fluid through a vapor compression circuit.

[0017] By utilizing an axial flux motor, the degree of complexity and / or the length of the flux path can be reduced compared to a radial flux motor, thereby reducing the amount of loss associated with the length of the flux path. For example, in a radial flux motor, the flux path can reach from the first rotor pole to the first stator teeth located at the first end of the stator, through the stator core to the second stator teeth located at the second end of the stator, and finally return to the second rotor pole. Thus, the flux path can follow a two-dimensional path and extend approximately perpendicular to the axis of rotation of the radial flux motor. Conversely, the flux path of an axial flux motor can extend approximately along (for example, parallel to) the axis of rotation of the axial flux motor and can extend over a shorter distance compared to the flux path of a radial flux motor. Furthermore, since the magnetic flux path in an axial flux motor generally extends along the rotation axis of the axial flux motor (for example, parallel and aligned with it), the magnetic flux path can be one-dimensional, which allows for the use of various materials (e.g., grain-oriented electrical steel sheets) that provide increased permeability compared to the materials used in conventional radial flux motors in the manufacture and assembly of axial flux motors. In this way, electrons traveling through the stator windings can travel shorter distances in an axial flux motor compared to a radial flux motor, and / or can travel through components with less copper and / or iron, thereby reducing losses associated with longer travel distances and / or increased amounts of copper and / or iron. In addition, because electrons traverse shorter paths in an axial flux motor compared to a radial flux motor, the strength of the magnetic field between the stator and rotor can be increased compared to a radial flux motor, thereby increasing efficiency and power density.

[0018] Furthermore, it is now recognized that the winding orientation of axial flux motors can offer certain advantages in HVAC&R systems. For example, the winding orientation relative to the stator in an axial flux motor can reduce the amount of winding bending around the stator ends (e.g., overhangs) compared to a radial flux motor. In this way, losses associated with electron interference around the stator bends (as in a radial flux motor) can be reduced, thereby improving the efficiency of the axial flux motor and, consequently, the compressor in the HVAC&R system. Reducing the amount of overhang also allows for an increase in the number of winding turns, which can improve the torque-to-weight ratio of the axial flux motor and / or reduce the amount of heat generated by electron interference around the stator bends. In addition, the windings of an axial flux motor can be in direct contact with the stator, which facilitates more efficient cooling compared to a radial flux motor, which dissipates heat through a stator core typically composed of materials with low thermal conductivity. Therefore, the cooling requirements for the components of the HVAC&R system may be reduced, which can enable more efficient and cost-effective operation of the HVAC&R system.

[0019] Furthermore, axial flux motors may contain fewer components and occupy less footprint compared to radial flux motors, thereby increasing the amount of space available for other components of the HVAC&R system (e.g., and / or reducing the amount of space occupied by the HVAC&R system), enabling an improved arrangement of components in the HVAC&R system, and / or improving the torque-to-weight ratio of the HVAC&R system (e.g., increasing power density). For example, axial flux motors may not include a gearbox, which otherwise would result in a reduction in compressor efficiency. In addition, by employing fewer components, axial flux motors may be associated with reduced amounts of iron and / or copper compared to radial flux motors, which can result in improved efficiency as iron losses are reduced.

[0020] Now looking at the drawings, Figure 1 is a perspective view of one embodiment of an environment for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 10 within a building 12 for a typical commercial environment. The HVAC&R system 10 may include a vapor compression system 14 (e.g., a chiller system, a heat pump system) that supplies a cooled liquid, which can be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 for supplying a warm liquid to heat the building 12, and an air distribution system for circulating air through the building 12. The air distribution system may also include an air return duct 18, an air supply duct 20, and / or an air treatment device 22. In some embodiments, the air treatment device 22 may include a heat exchanger connected to the boiler 16 and the vapor compression system 14 by conduits 24. The heat exchanger in the air treatment device 22 may receive either a heated liquid from the boiler 16 or a cooled liquid from the vapor compression system 14, depending on the operating mode of the HVAC&R system 10. Although the HVAC&R system 10 is shown as having separate air treatment equipment on each floor of the building 12, in other embodiments the HVAC&R system 10 may include air treatment equipment 22 and / or other components that can be shared between or between floors.

[0021] Figures 2 and 3 are embodiments of a vapor compression system 14 that can be used within an HVAC&R system 10. The vapor compression system 14 can circulate a working fluid (e.g., refrigerant) through a circuit that begins at a compressor 32. The circuit can also include a condenser 34, an expansion valve(s) or expansion device 36(s), and a liquid chiller or evaporator 38. The vapor compression system 14 can further include a control panel 40 having an analog-to-digital (A / D) converter 42, a microprocessor 44, a non-volatile memory 46, and / or an interface board 48. Some examples of fluids that can be used as the working fluid in the vapor compression system 14 include water vapor, R-718, hydrofluorocarbon (HFC)-based working fluids (e.g., R-410A, R-407, R-134a), hydrofluoroolefin (HFO), “natural” working fluids (e.g., ammonia (NH3), R-717, carbon dioxide (CO2), R-744), or hydrocarbon-based working fluids, or any other suitable working fluid.

[0022] In some embodiments, the vapor compression system 14 can use one or more of a variable speed drive (VSD) 52, a motor 50, a compressor 32, a condenser 34, an expansion valve or expansion device 36, and / or an evaporator 38. The motor 50 can drive the compressor 32 and can be powered by a variable speed drive (VSD) 52. The VSD 52 receives AC power having a specific fixed line voltage and a fixed line frequency from an alternating current (AC) power source and provides power having a variable voltage and a variable frequency to the motor 50. In other embodiments, the motor 50 can be powered directly from an AC power source or a direct current (DC) power source. The motor 50 can include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor.

[0023] The compressor 32 compresses the vapor of the working fluid and sends the vapor through the discharge passage to the condenser 34. In some embodiments, the compressor 32 can be a centrifugal compressor. The vapor of the working fluid sent to the condenser 34 by the compressor 32 can transfer heat to the cooling fluid (e.g., water or air) in the condenser 34. As a result of the heat transfer with the cooling fluid, the vapor of the working fluid can condense into a liquid of the working fluid within the condenser 34. The liquid working fluid from the condenser 34 can flow through the expansion device 36 to the evaporator 38. In the embodiment illustrated in FIG. 3, the condenser 34 is water-cooled and includes a tube bundle 54 connected to a cooling tower 56 that supplies the cooling fluid to the condenser.

[0024] The liquid working fluid sent to the evaporator 38 can absorb heat from another cooling fluid, which may or may not be the same cooling fluid used in the condenser 34. The liquid working fluid in the evaporator 38 can undergo a phase change from the liquid working fluid to the vapor of the working fluid. As shown in the illustrated embodiment of FIG. 3, the evaporator 38 can include a tube bundle 58 having a supply pipe 60S and a return pipe 60R connected to a cooling load 62. The cooling fluid of the evaporator 38 (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) flows into the evaporator 38 through the return pipe 60R and out of the evaporator 38 through the supply pipe 60S. The evaporator 38 can reduce the temperature of the cooling fluid in the tube bundle 58 through heat transfer with the working fluid. The tube bundle 58 in the evaporator 38 can include a plurality of tubes and / or a plurality of tube bundles. In either case, the vapor of the working fluid flows out of the evaporator 38 and returns to the compressor 32 through the suction pipe to complete the cycle.

[0025] Figure 4 is a schematic diagram of a vapor compression system 14 having an intermediate circuit 64 incorporated between a condenser 34 and an expansion device 36. The intermediate circuit 64 may have an inlet pipe 68 that is directly fluid-connected to the condenser 34. In other embodiments, the inlet pipe 68 may be indirectly fluid-connected to the condenser 34. As shown in the illustrated embodiment of Figure 4, the inlet pipe 68 includes a first expansion device 66 positioned upstream of the intermediate vessel 70. In some embodiments, the intermediate vessel 70 may be a flash tank (e.g., a flash intercooler). In other embodiments, the intermediate vessel 70 may be configured as a heat exchanger or a "surface economizer". In the illustrated embodiment of Figure 4, the intermediate vessel 70 is used as a flash tank, and the first expansion device 66 is configured to reduce (e.g., expand) the working fluid pressure of the liquid received from the condenser 34. During the expansion process, a portion of the liquid may vaporize, and thus the intermediate vessel 70 can be used to separate the vapor from the liquid received from the first expansion device 66.

[0026] In addition, the intermediate container 70 may provide further expansion of the liquid working fluid because the pressure it experiences when it enters the intermediate container 70 is reduced (for example, due to a rapid increase in volume that occurs when it flows into the intermediate container 70). The vapor in the intermediate container 70 may be drawn in by the compressor 32 through the suction pipe 74 of the compressor 32. In other embodiments, the vapor in the intermediate container may be drawn in to the intermediate stage of the compressor 32 (for example, not the suction stage). The liquid that collects in the intermediate container 70 may have a lower enthalpy than the liquid working fluid flowing out of the condenser 34 due to expansion in the expansion device 66 and / or in the intermediate container 70. The liquid from the intermediate container 70 may then flow through the pipe 72 to the evaporator 38 through the second expansion device 36.

[0027] It should be understood that any of the features described herein can be incorporated into the vapor compression system 14 or any other suitable HVAC&R system. For example, the technology can be incorporated into an HVAC&R system having a compressor such as compressor 32. The following discussion describes the technology incorporated into an embodiment of compressor 32 configured as a single-stage compressor. However, it should be noted that the systems and methods described herein can be incorporated into other embodiments of compressor 32 and HVAC&R system 10.

[0028] As described above, this embodiment relates to an HVAC&R system having an axial flux motor configured to operate to drive a compressor such as a compressor 32. For example, Figure 5 is a partial perspective view of one embodiment of an HVAC&R system 10, illustrating a compression system 99 having a motor 100 (e.g., an axial flux motor) configured to drive a compressor 32 of the HVAC&R system 10. The motor 100 includes a housing 102 configured to be coupled to the compressor 32. According to this technology, the motor 100 (e.g., the housing 102) may be directly coupled to the compressor 32 (e.g., without an intervening gearbox), which may enable more efficient operation of the compressor 32 and a more compact packaging of the HVAC&R system 10. While the compressor 32 is operating, the axial flux motor 100 can rotate its rotor shaft at various rates or speeds along its rotation axis 104, thereby supplying power to or driving the shaft (and therefore the impeller) of the compressor 32. It should be understood that the rotation axis 104 may correspond to the rotation axis of a component of the compressor 32 (e.g., the impeller of the compressor 32).

[0029] The axial flux motor 100 may be communicatively coupled via a connection 106 to a control system 150 (e.g., a control device, control panel 40) configured to control the operation of the motor 100. The control system 150 may include a processing circuit 152 and a memory 154 (e.g., a storage device) configured to store commands that, when executed by the processing circuit 152, cause the processing circuit 152 to operate the motor 100 at a specific speed to satisfy the load requirements of the compressor 32. For example, based on a control signal received from the control system 150 (or another suitable control device or system), the motor 100 may operate the rotation of its rotor shaft from a stationary state (e.g., a state corresponding to zero revolutions per minute [RPM]) to an operating start state or an operating continuation state (e.g., a state corresponding to approximately 500 RPM, 1000 RPM, 2500 RPM, 5000 RPM, and / or other suitable speeds). This will be described in more detail below.

[0030] As described above, by integrating the axial flux motor 100 into the HVAC&R system 10 to drive the operation of the compressor 32, the compressor 32 may not include a gearbox, thereby reducing the costs associated with the manufacture and assembly of the HVAC&R system 10. Losses associated with including a gearbox (e.g., efficiency losses) are also avoided, resulting in more efficient operation of the compressor 32 and the HVAC&R system 10. In addition, the flux path of the motor 100 can be simplified, and the length of the flux path of the motor 100 can be shortened, thereby reducing the passive losses associated with the more complex and / or longer relative flux path seen in radial flux motors. That is, electrons moving along the flux path in the axial flux motor 100 can travel shorter distances and / or through components with reduced amounts of iron compared to a radial flux motor, thereby reducing the amount of losses associated with increased travel distance and / or increased amount of iron. Furthermore, by utilizing the axial flux motor 100, heat dissipation losses and core losses can be reduced, thereby improving the efficiency associated with the motor 100.

[0031] For example, the axial flux motor 100 described herein may employ fewer components with a reduced amount of iron compared to a radial flux motor. By reducing the amount of iron associated with the axial flux motor, iron loss can be reduced. In addition, in a radial flux motor, the magnetic flux path can travel through the core in multiple (e.g., two or more) dimensions across the axis of rotation (e.g., across the iron core), whereas in an axial flux motor, the magnetic flux path travels through the core in one dimension that is substantially parallel to the axis of rotation. Thus, the axial flux motor may be associated with reduced iron loss compared to a radial flux motor due to the orientation of the magnetic flux path traveling through the core in one dimension. Furthermore, as will be considered below, the stator windings of the axial flux motor 100 may be oriented such that coil overhang and / or winding bending around the ends of the stator can be reduced and / or substantially eliminated. For example, as discussed above, a radial flux motor may include a stator having windings that bend (e.g., axially outward) around opposing ends of the stator. Because the windings are bent around the ends of the stator, electrons moving through the windings may communicate with and / or interfere with each other, which can result in a reduction in efficiency. Therefore, the configuration of the axial flux motor 100 can eliminate coil overhang and / or winding bending around the ends of the stator, thereby reducing copper loss and improving efficiency compared to a radial flux motor.

[0032] In addition, the axial flux motor 100 may be better suited to HVAC&R systems utilizing low-pressure working fluids. Specifically, the axial flux motor 100 may enable improved efficiency when directly driving the compressor 32, during partial load operation, and / or when the compressor 32 is operating at lower rotational speeds, and / or may be particularly suited to low-pressure working fluids such as R1233zd that can be circulated through the working fluid circuit by the compressor 32. Therefore, by utilizing the axial flux motor 100, it may be possible to improve the operation of HVAC&R systems 10 that utilize working fluids with low global warming potential (GWP). In this way, the technology makes it possible to reduce the generation and emission of greenhouse gases, thereby mitigating climate change.

[0033] When using a low-pressure working fluid, it may be beneficial to operate the compressor 32 at a lower impeller tip speed. In addition, the density of the working fluid may also be reduced due to the low-pressure working fluid flow. As a result, the size of the impeller can be increased to increase its surface area, thereby allowing the impeller to guide the low-pressure working fluid into the volute of the compressor 32 and compress the low-pressure working fluid. Therefore, the axial flux motor 100 may be particularly well suited to HVAC&R systems employing low-pressure working fluids (e.g., low-GWP working fluids). This is because the axial flux motor 100 is configured to operate with a higher torque-to-weight ratio compared to a radial flux motor, which allows the axial flux motor 100 to operate a larger impeller at a lower relative impeller tip speed, thereby sufficiently compressing the low-pressure working fluid and guiding it through the HVAC&R system 10. Furthermore, as described above, by driving the compression of a low-pressure working fluid through the vapor compression circuit via the axial flux motor 100, the HVAC&R system 10 can be operated with a lower environmental impact (for example, with reduced greenhouse gas emissions).

[0034] Figure 6 is an exploded perspective view of one embodiment of a motor 100 (e.g., an axial flux motor) configured to operate a compressor 32. The housing 102 defines a volume 108 (e.g., a cavity) configured to house the components of the motor 100. For example, a rotor shaft 110, a first rotor 112, a second rotor 114, and a stator 116 may be located within the volume 108. Based on electrical signals sent from a control system 150 to the windings 118 of the stator 116, the first and second rotors 112, 114 may rotate around the rotation axis 104 of the motor 100, causing the rotor shaft 110 to rotate. For example, the stator 116 may include one or more windings 118 (e.g., coils) arranged around a stator core 119 and define one or more electromagnets 120 configured to receive current from the control system 150. When current is passed through the windings 118 of the electromagnets 120, one or more electromagnets 120 may be activated, thereby enabling the first and second rotors 112, 114 to rotate about the axis of rotation 104. For example, each of the first and second rotors 112, 114 may include one or more stationary magnets 122 (e.g., permanent magnets, rare-earth magnets) configured to bias the rotors 112, 114 in a particular direction based on the interaction between the magnets 122 and the electric field generated through one or more electromagnets 120 of the stator 116. As shown, the rotors 112, 114 may be coupled to a rotor shaft 110, so that when the rotors 112, 114 rotate, the rotor shaft 110 also rotates. The rotor shaft 110 may be coupled to a shaft of a compressor 32, which may be configured to drive the impeller of the compressor 32. Therefore, the rotation of the rotor shaft 110 can drive the rotation of the compressor shaft 32, thereby enabling the compressor 32 to compress the working fluid through a vapor compression circuit such as the vapor compression circuit 14.

[0035] During operation of the motor 100, a magnetic flux path 124 may be generated between the first and second rotors 112, 114 and the stator 116, thereby causing the rotors 112, 114 to rotate about the axis of rotation 104. In certain embodiments, the magnets 122 of the rotors 112, 114 may be arranged around the axis of rotation 104 in an alternating configuration, thereby associating each adjacent magnet 122 with a different polarity (e.g., north pole, south pole). For example, the first magnet 122A of the first rotor 112 may be associated with the north pole (e.g., north pole configuration), and therefore each of the two magnets 122 adjacent to the first magnet 122A may be associated with the south pole (e.g., south pole configuration). On the other hand, each winding 118 of the magnet 120 may allow the polarity of each magnet 120 to be alternately switched depending on the direction of an electrical signal (e.g., phase signal) directed through the winding 118. For example, the control device 150 may be configured to change the polarity of each of the associated magnets 120 based on the direction of a phase signal transmitted through the corresponding winding 118 of each magnet 120. Thus, each of the magnets 120 can be excited with an electrical signal having a specific direction (e.g., via the control device 150), thereby enabling the realization of a desired polarity for a particular magnet 120.

[0036] For example, during operation, a first set of coils 118A associated with the electromagnet 120A may receive a signal from the control device 150. This signal may be directed through the coils 118A in a specific direction such that the electromagnet 120A has a north pole configuration. Meanwhile, the first magnet 122A on the first rotor 112 may have a south pole configuration. Therefore, when an operating signal is transmitted in a specific direction through the windings 118A of the electromagnet 120A, the first magnet 122A may be attracted toward the electromagnet 120A, thereby generating a tangential force 130 on the first rotor 112, causing the first rotor 112 to rotate. Simultaneously, as the first rotor 112 rotates, a second magnet 122B positioned adjacent to the first magnet 122A (and thus having a north pole configuration) may align with the electromagnet 120A (for example, along the axis of rotation 104). Because the second magnet 122B has a north pole configuration, and the electromagnet 120A also has a north pole configuration, these two magnets can repel each other, thereby generating an additional tangential force 132 on the first rotor 112. The tangential forces 130 and 132 can be added together, thereby enabling the rotor 112 to rotate relative to the stator 116.

[0037] When magnet 122A aligns with electromagnet 120A along the axis of rotation 104, the net force on magnet 122A of rotor 112 may be zero. However, rotor 112 may continue to rotate due to inertia. As rotor 112 continues to rotate, control device 150 may send a signal to stop winding 118A of electromagnet 120A, and send an additional signal to activate winding 118B of electromagnet 120B. This signal may travel through winding 118B of electromagnet 120B so that electromagnet 120B has an N-pole configuration. Thus, as in the example above, magnet 122A (which may have an S-pole configuration) may be attracted to electromagnet 120B, while magnet 122B (which may have an N-pole configuration) may be repelled from electromagnet 120B, thereby generating tangential forces 130, 132 that enable rotor 112 to continue rotating. It should be understood that in certain embodiments, the control device 150 may progressively adjust (e.g., gradually adjust, stepwise adjust) the magnitude of the activation and / or deactivation signals (e.g., the magnitude of the phase signal) transmitted to each set of windings 118. For example, while a particular electromagnet 120 is activated (e.g., while the windings 118 of electromagnet 120 are activated), the magnitude of the activation signal may increase from zero to an upper threshold, and while a particular electromagnet is deactivated (e.g., while the windings 118 of electromagnet 120 are deactivated), the magnitude of the deactivation signal may decrease from an upper threshold to zero. In this way, transient torque outputs may be reduced, resulting in a more consistent torque output.

[0038] In certain embodiments, the motor 100 may employ various sensors 160 to determine the position of the magnets 122 of the rotors 112 and 114 relative to the electromagnets 120 of the stator 116. For example, the sensors 160 may include motion sensors and / or position sensors configured to detect the position of the magnets 122 of the rotors 112 and 114. In certain embodiments, the sensors 160 may be coupled (e.g., mounted) on the stator 116. The sensors 160 may be communicatively coupled to a control unit 150, thereby enabling the control unit 150 to receive data and / or feedback from the sensors 160 and, in response, determine when to send actuation signals and / or stop signals to the respective windings 118 of the electromagnets 120. Using the above example, the control device 150 may, based on feedback from the sensor 160, decide to decrease the phase signal transmitted to the electromagnet 120A and increase the phase signal transmitted to subsequent electromagnets 120 (e.g., magnets 120 adjacent to magnet 120A) based on the first magnet 122A of the first rotor 112 which is aligned with the electromagnet 120A along the rotation axis 104.

[0039] In certain embodiments, the stationary magnet 122 may be positioned at a threshold distance 162 from the rotation axis 104 of the motor 100. This distance may be greater than the distance between the stationary magnet on the rotor of the radial flux motor and the rotation axis of the radial flux motor. By positioning the stationary magnet 122 at a threshold distance from the rotation axis 104 of the motor 100, the torque-to-weight ratio of the motor 100 may be improved. For example, the magnitude of the torque of the motor 100 may be a function of the tangential force generated (e.g., the magnetic force generated through the interaction between the electromagnet 120 and the stationary magnet 122) multiplied by the distance between the tangential force and the rotation axis 104. Therefore, by positioning the magnet 122 at a threshold distance from the rotation axis 104, the distance between the magnet 122 and the rotation axis 104 may increase, thereby increasing the torque of the motor 100.

[0040] As illustrated, the flux path 124 may generally extend in a direction substantially similar to the direction of the rotation axis 104 (e.g., along the direction of the rotation axis 104). For example, in certain embodiments, the flux path 124 may generally extend in a direction substantially parallel to the rotation axis 104. In this way, the length of the flux path may be reduced compared to the length of the flux path in a radial flux motor, thereby resulting in improved efficiency. In addition, due to the arrangement of the components of the axial flux motor 100, the axial flux motor 100 may be oriented such that the rotation axis 104 is oriented along the vertical axis, thereby reducing the compressor's suction angle (e.g., from 90 degrees to 45 degrees, from 90 degrees to 0 degrees) and / or increasing the compressor's discharge angle (e.g., from 45 degrees to 90 degrees). In this way, the flow losses (e.g., pressure loss, fluid restriction, etc.) induced and / or imparted to the working fluid introduced through the compressor 32 (e.g., through a bend in the suction conduit extending to the compressor 32) can be reduced, which in turn can result in more efficient overall operation of the compressor 32 and the HVAC&R system 10.

[0041] For example, Figure 7 is a schematic diagram of one embodiment of an HVAC&R system 10 having an axial flux motor 100 oriented along the vertical axis 200 of the HVAC&R system 10 (e.g., the rotation axis 104 of the axial flux motor 100 oriented along the vertical axis 200) and configured to drive a compressor 32. As illustrated in Figure 7, by employing the axial flux motor 100 to operate the compressor 32 in accordance with this technology, the suction pipe 202 (e.g., suction conduit) extending from the evaporator 38 to the suction side (e.g., the inlet) of the compressor 32 can be oriented linearly along the vertical axis 200 of the HVAC&R system 10 and generally aligned with the rotation axis 104. In this way, by employing an axial flux motor 100 to drive the compressor 32 and orienting the rotation axis 104 of the axial flux motor 100 along the vertical axis 200, bends or kinks in the suction pipe 202 can be significantly reduced and / or eliminated, thereby enabling the compressor 32 to draw the working fluid more efficiently from the evaporator 38 to the inlet of the compressor 32 (e.g., the suction side). For example, the compressor 32 can draw the working fluid from the evaporator 38 to the compressor 32 (e.g., linearly) while reducing flow losses compared to a system incorporating a bent or arc-shaped suction pipe. Thus, the HVAC&R system 10 can operate more efficiently, with reduced energy consumption and correspondingly reduced emissions.

[0042] In certain embodiments, the position of the condenser 34 can be adjusted to further reduce flow losses and / or pressure drops induced and / or imparted to the working fluid circulating through the HVAC&R system 10. For example, as illustrated in Figure 7, the condenser 34 can be positioned higher along the vertical axis 200 relative to the evaporator 38. In this way, the bends or curves in the discharge pipe 204 from the discharge side of the compressor 32 to the condenser 34 can be substantially reduced and / or eliminated, thereby enabling the compressor 32 to discharge the working fluid more efficiently toward the condenser 34. For example, the compressor 32 can discharge the working fluid toward the condenser 34 while reducing flow losses and / or pressure drops compared to a system incorporating a bent or arc-shaped discharge pipe. Thus, the HVAC&R system 10 can operate more efficiently, with reduced energy consumption and correspondingly reduced emissions, among other things.

[0043] In certain embodiments, the rotation axis 104 of the motor 100 may extend at an angle (e.g., a non-zero angle, an oblique angle) with respect to the vertical axis 200. For example, Figure 8 is a schematic diagram of one embodiment of an HVAC&R system 10 having an axial flux motor 100 configured to drive a compressor 32, which is oriented at an angle (e.g., a non-zero angle, an oblique angle, a 45-degree angle) with respect to the vertical axis 200 of the HVAC&R system 10 (e.g., oriented with respect to the direction of gravity). As illustrated in Figure 8, by employing an axial flux motor 100 to operate the compressor 32, the suction pipe 202 from the evaporator 38 to the suction side of the compressor 32 may be oriented at an angle (e.g., a 45-degree angle) with respect to the vertical axis 200, and may extend linearly between the evaporator 36 and the suction side of the compressor 32. In other words, the bends or kinks in the suction pipe 202, which are typically included in existing systems, can be substantially reduced and / or eliminated, thereby enabling the compressor 32 to draw the working fluid more efficiently into the suction side of the compressor 32. Similarly, the discharge pipe 204 can be linearly oriented from the discharge side of the compressor 32 to the condenser 34. That is, by oriented the axial flux motor 100 at an angle (e.g., a non-zero angle) with respect to the vertical axis, the compressor 32 can discharge the working fluid to the condenser 34 (e.g., directly). That is, the bends or kinks in the discharge pipe 204 can be substantially reduced and / or eliminated, thereby enabling the compressor 32 to discharge the working fluid to the condenser 34 more efficiently. As a result, the compressor 32 (e.g., motor 100) and the HVAC&R system 10 can be operated with reduced energy consumption.

[0044] In embodiments in which the suction pipe 202 and / or discharge pipe 204 include a bent or arc-shaped conduit, it should be understood that embodiments of the present disclosure may employ a smaller pressure rise rate within the arc-shaped or bent portion of the conduit compared to conventional suction and / or discharge conduits. That is, the pressure rise rate in the bent or arc-shaped portion of the suction pipe 202 and / or discharge pipe 204 may be less than the threshold pressure rise rate. In this way, the flow loss associated with the bent or arc-shaped portion of the conduit that is below the threshold pressure rise rate may be reduced compared to the bent or arc-shaped portion of the conduit that is above the threshold pressure rise rate.

[0045] The technologies presented and claimed herein refer to and apply to tangible objects and specific examples of a practical nature that clearly improve the art, and are therefore not abstract, intangible, or purely theoretical. Furthermore, if any claims appended to this specification contain one or more elements designated as “means for carrying out the [function]” or “steps for carrying out the [function],” such elements are intended to be construed under Section 112(f) of the United States Patent Act. However, any claims containing elements designated in any other form are not intended to be construed under Section 112(f) of the United States Patent Act.

[0046] While only certain features and embodiments have been illustrated and described, those skilled in the art will be able to conceive of numerous modifications and changes (e.g., the size, dimensions, structure, shape, and proportions of various elements, the values ​​of parameters (e.g., temperature, pressure, etc.), mounting arrangements, the use of materials, color, orientation, etc.) without substantially departing from the novel teachings and merits of the subject matter enumerated in the claims. The order or sequence of steps of any process or method may be modified or rearranged according to alternative embodiments. It should be understood that the attached claims are intended to cover all such modifications and changes that fall within the true spirit of this disclosure.

[0047] Furthermore, as part of our efforts to provide a concise description of exemplary embodiments, not all features of actual implementations (i.e., those unrelated to the best currently envisioned mode for carrying out the disclosure, or unrelated to making the claimed disclosures implementable) may be described. It should be understood that, as with any engineering or design project, in the development of any such actual implementation, numerous implementation-specific decisions may be made. While such development efforts may be complex and time-consuming, they are still considered normal business practices of design, fabrication, and manufacturing for those skilled in the art who are interested in the disclosure, without excessive experimentation.

Claims

1. A compression system for heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, - A compressor configured to guide the working fluid through a vapor compression circuit, - An axial flux motor coupled to the compressor and configured to drive the rotation of the compressor, A compression system equipped with the following features.

2. The compression system according to claim 1, The aforementioned axial flux motor, - The rotor shaft coupled to the shaft of the compressor, - A first rotor equipped with a first magnet set, - A second rotor equipped with a second magnet set, - It is a stator, - One or more electromagnets, - One or more electric windings arranged around one or more electromagnets, configured such that the operation of the one or more electromagnets causes the first rotor and the second rotor to rotate about the rotation axis of the axial flux motor, A stator comprising, A compression system equipped with the following features.

3. The compression system according to claim 2, A compression system comprising a control device communicatively coupled to one or more electric windings, wherein the control device is configured to transmit signals for activating or deactivating one or more electromagnets, thereby causing the first rotor and the second rotor to rotate about the rotation axis of the axial flux motor.

4. The compression system according to claim 3, A compression system in which the control device is configured to control the polarity of one or more electromagnets based on the direction of each of the signals transmitted through one or more electric windings.

5. A compression system according to claim 3 or 4, A compression system configured to generate magnetic flux lines between the first magnet set, the one or more electromagnets, and the second magnet set by the operation of one or more electromagnets via the control device.

6. The compression system according to claim 5, A compression system in which the magnetic flux lines extend substantially parallel to the rotation axis of the axial flux motor.

7. A compression system according to one of claims 3 to 6, A compression system in which the control device is configured to increase the magnitude of each of the signals from zero to an upper threshold to activate one of the one or more electromagnets, and to decrease the magnitude of each of the signals from the upper threshold to zero to deactivate one of the one or more electromagnets.

8. The compression system according to claim 7, A compression system in which the control device is configured to operate in a sequence, so that the first electromagnet among the one or more electromagnets operates and stops in the sequence before the second electromagnet among the one or more electromagnets operates and stops in the sequence.

9. A compression system according to one of claims 1 to 8, A compression system in which the first magnet set and the second magnet set include rare earth magnets.

10. A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, - A compressor configured to guide the working fluid through a vapor compression circuit, - A condenser configured to place the working fluid in a first heat exchange relationship, - An evaporator configured to place the working fluid in a second heat exchange relationship, - An axial flux motor is coupled to the compressor and configured to drive the rotation of the compressor to forcibly flow the working fluid through the vapor compression circuit, Equipped with an HVAC&R system.

11. The HVAC&R system according to claim 10, The aforementioned axial flux motor, - Impeller The rotor shaft is coupled to the impeller of the compressor, - At least one rotor having one or more magnets, - A stator comprising one or more electromagnets and one or more electric windings arranged around the one or more electromagnets, Equipped with an HVAC&R system.

12. The HVAC&R system according to claim 11, An HVAC&R system comprising a control device configured to transmit signals through one or more electric windings to excite one or more electromagnets, wherein the excitation of one or more electromagnets causes at least one rotor to rotate about the rotation axis of the axial flux motor.

13. The HVAC&R system according to claim 12, An HVAC&R system in which one or more magnets are positioned at a threshold distance from the rotation axis of the axial flux motor.

14. An HVAC&R system according to one of claims 10 to 13, An HVAC&R system in which the rotation axis of the axial flux motor is oriented along the vertical axis.

15. The HVAC&R system according to claim 14, An HVAC&R system comprising a suction pipe positioned between the evaporator and the suction side of the compressor, wherein the suction pipe extends linearly along the vertical axis from the evaporator to the suction side of the compressor.

16. An HVAC&R system according to claim 14 or 15, An HVAC&R system in which the condenser is positioned higher relative to the evaporator along the vertical axis.

17. An HVAC&R system according to one of claims 10 to 16, An HVAC&R system in which the rotation axis of the axial flux motor extends through the axial flux motor and is oriented at a certain angle with respect to a vertical axis oriented with respect to the direction of gravity.

18. The HVAC&R system according to claim 17, An HVAC&R system comprising a discharge pipe positioned between the discharge side of the compressor and the condenser, wherein the discharge pipe extends linearly from the discharge side of the compressor to the condenser, and guides the working fluid linearly from the discharge side of the compressor into the condenser.

19. A compression system for heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, - A compressor configured to guide the working fluid through a vapor compression circuit, - An axial flux motor coupled to the compressor and configured to drive the rotation of the compressor, The axial flux motor is equipped with, - A first rotor equipped with a first magnet set, - A second rotor equipped with a second magnet set, - A stator comprising one or more electromagnets and one or more electric windings arranged around the one or more electromagnets, - A control device configured to be communicatively coupled to one or more electric windings and to activate or deactivate one or more electromagnets via signals transmitted through the one or more electric windings, thereby causing the first rotor and the second rotor to rotate about the rotation axis of the axial flux motor, Equipped with, Compression system.

20. The compression system according to claim 19, A compression system comprising one or more sensors communicatively coupled to the control device, wherein the one or more sensors are configured to detect the respective positions of the first magnet set and the second magnet set relative to the one or more electromagnets, and the control device is configured to control the operation or deactivation of the one or more electromagnets based on the respective positions of the first magnet set and the second magnet set relative to the one or more electromagnets.

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