Inflatable sealing system for HVAC&r system

Abstract

A compressor system includes a housing having an impeller disposed therein and a motor disposed within the housing, where the motor includes a rotor shaft coupled to the impeller, and the motor is configured to drive rotation of the rotor shaft and the impeller. The compressor system also includes a sealing system disposed within the housing, where the sealing system includes a sealing element circumferentially disposed around the rotor shaft and configured to bias against a surface of the rotor shaft in a first configuration, where the housing includes an injection pathway formed therein, where the injection pathway is configured to direct a pressurized fluid into the sealing element to maintain the sealing element in the first configuration.

Description

INFLATABLE SEALING SYSTEM FOR HVAC&R SYSTEMCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from and the benefit of U.S. Provisional Application No. 63 / 614,031, entitled “INFLATABLE SEALING SYSTEM FOR HVAC&R SYSTEM,” filed December 22, 2023, which is herein incorporated by reference in its entirety for all purposes.BACKGROUND

[0002] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

[0003] Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, or vapor compression systems, are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. An HVAC&R system generally circulates a working fluid (e.g., refrigerant), which changes phases between vapor, liquid, and combinations thereof in response to exposure to different temperatures and pressures associated with operation of the HVAC&R system. For example, the HVAC&R system may utilize one or more compressors to circulate the working fluid to a heat exchanger, which may transfer heat between the working fluid and another fluid (e.g., cooling fluid) flowing through the heat exchanger. In some applications, a motor that powers the compressor(s) may include rotating components that operate to rotate an impeller of the compressor(s), thereby enabling the compressor(s) to compress the working fluid and deliver the working fluid to other components of the vapor compression system. A motor cooling system may be utilized to cool the motor during operation of the HVAC&R system. Unfortunately, existing compressors, motors, and motor cooling systems are susceptible to various inefficiencies that may reduce efficiency of the HVAC&R system and / or may reduce a useful life of components of the HVAC&R system.SUMMARY

[0004] A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below.

[0005] In an embodiment, a compressor system includes a housing having an impeller disposed therein and a motor disposed within the housing, where the motor includes a rotor shaft coupled to the impeller, and the motor is configured to drive rotation of the rotor shaft and the impeller. The compressor system also includes a sealing system disposed within the housing, where the sealing system includes a sealing element circumferentially disposed around the rotor shaft and configured to bias against a surface of the rotor shaft in a first configuration, where the housing includes an injection pathway formed therein, where the injection pathway is configured to direct a pressurized fluid into the sealing element to maintain the sealing element in the first configuration.

[0006] In another embodiment, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a compressor configured to compress a working fluid and circulate the working fluid through a working fluid circuit, a motor coupled to the compressor via a rotor shaft and configured to drive operation of the compressor via rotation of the rotor shaft, and a sealing system configured to limit an amount of fluid migration between the motor and the compressor. The sealing system includes a sealing element configured to receive a pressurized fluid to transition the sealing element from a first configuration to a second configuration based on operation of a pressurized fluid source fluidly coupled to the sealing element, wherein a side of the sealing element is configured to engage with a surface of the rotor shaft in the second configuration in response to activation of the pressurized fluid source, and wherein the side of the sealing element is configured to disengage from the surface of the rotor shaft in the first configuration in response to deactivation of the pressurized fluid source.

[0007] In another embodiment, a sealing system for a motor of a compressor includes a sealing element circumferentially disposed about a rotor shaft of the motor and configured to transitionbetween a delated configuration and an inflated configuration, where the sealing element comprises a surface configured to disengage from an outer surface of the rotor shaft in the deflated configuration and contact the outer surface of the rotor shaft in the inflated configuration. The sealing system also includes a pressurized fluid source configured to provide a pressurized fluid, where the sealing element is configured to transition from the deflated configuration to the inflated configuration in response to the pressurized fluid source providing the pressurized fluid, and a controller configured to control operation of the pressurized fluid source to transition the sealing element between the deflated configuration and the inflated configuration in response to a detected operational state of the compressor.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

[0009] FIG. 1 is a perspective view of an embodiment of a building that may utilize a heating, ventilating, air conditioning, and / or refrigeration (HVAC&R) system in a commercial setting, in accordance with an aspect of the present disclosure;

[0010] FIG. 2 is a perspective view of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0011] FIG. 3 is a schematic of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0012] FIG. 4 is a schematic of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0013] FIG. 5 is a cross-sectional side view of an embodiment of a compressor of a vapor compression system, illustrating a motor and a sealing system of the compressor, in accordance with an aspect of the present disclosure;

[0014] FIG. 6 is a perspective view of an embodiment of a sealing element of a sealing system for a motor of a compressor, in accordance with an aspect of the present disclosure; and

[0015] FIG. 7 is a cross-sectional side view of a portion of an embodiment of a compressor, illustrating a sealing system for a motor of the compressor, in accordance with an aspect of the present disclosureDETAILED DESCRIPTION

[0016] One or more specific embodiments of the present disclosure will be described below. These described embodiments are examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made to achieve the developers’ specific goals, such as compliance with system -related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0017] When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0018] As used herein, the terms “approximately,” “generally,” “substantially,” and so forth, are intended to convey that the property value being described may be within a relatively small range of the property value, as those of ordinary skill would understand. For example, when a property value is described as being “approximately” equal to (or, for example, “substantially similar” to) a given value, this is intended to convey that the property value may be within + / - 5%, within + / - 4%, within + / - 3%, within + / - 2%, within + / - 1%, or even closer, of the given value. Similarly, when a given feature is described as being “substantially parallel” to another feature, “generally perpendicular” to another feature, and so forth, this is intended to convey that the given feature iswithin + / - 5%, within + / - 4%, within + / - 3%, within + / - 2%, within + / - 1%, or even closer, to having the described nature, such as being parallel to another feature, being perpendicular to another feature, and so forth. Mathematical terms, such as “parallel” and “perpendicular,” should not be rigidly interpreted in a strict mathematical sense, but should instead be interpreted as one of ordinary skill in the art would interpret such terms. For example, one of ordinary skill in the art would understand that two lines that are substantially parallel to each other are parallel to a substantial degree, but may have minor deviation from exactly parallel.

[0019] As briefly discussed above, a heating, ventilation, air conditioning, and / or refrigeration (HVAC&R) system may be configured to operate to satisfy heating and / or cooling demands within a building, home, or other suitable structure or system. For example, the HVAC&R system may include a vapor compression system (e.g., a chiller system, heat pump system) that transfers thermal energy between a working fluid (e.g., water, refrigerant, heat transfer fluid) and a fluid to be conditioned (e.g., air, water, or brine). In some embodiments, the working fluid and the fluid to be conditioned may be the same fluid (e.g., water, same type of fluid). The vapor compression system may include one or more vapor compression circuits (e.g., heat pumps, working fluid circuits) that each include one or more heat exchangers, such as a condenser and an evaporator that are fluidly coupled to one another via one or more conduits (e.g., vapor compression circuit, working fluid circuit, refrigeration circuit). Further, each vapor compression circuit may include a compressor configured to pressurize and circulate the working fluid through the vapor compression circuit and, thus, enable the transfer of thermal energy between the working fluid and the fluid to be conditioned via the one or more heat exchangers. To facilitate different operating modes, the vapor compression system may include one or more controllable features or components, such as valves, expansion devices, a coil fan, a condenser pump, and / or an evaporator pump. To this end, the vapor compression system may include a controller configured to determine an operating mode (e.g., an active operating mode) of the vapor compression system and / or to control one or more of the controllable features or components (e.g., valves, expansion devices, pumps, fans) to operate the vapor compression system in the operating mode in a desired manner. In certain embodiments, the vapor compression system may be a heat pump system configured to facilitate a flow of working fluid through the vapor compression circuit in different directions for different operating modes. In other embodiments, the working fluid may flowthrough the vapor compression circuit in the same direction during multiple (e.g., all) modes of operation.

[0020] The compressor (e.g., centrifugal compressor) of a vapor compression system (e.g., a heat pump system) may be designed for certain operating conditions, which may include one or more characteristics, properties, and / or parameters of the working fluid (e.g., refrigerant, water). For example, compressors may be designed and / or selected for implementation in the HVAC&R system based on a type of the working fluid, working fluid flow (e.g., flow rate), working fluid temperature and / or pressure conditions at a suction inlet of the compressor, working fluid temperature and / or pressure conditions at a discharge outlet of the compressor, operating environment (e.g., ambient) conditions (e.g., temperature, pressure), another suitable parameter or metric, or any combination thereof.

[0021] In certain HVAC&R systems, water may be utilized as a working fluid, and the compressor of the vapor compression system (e.g., heat pump system) may be configured to operate to circulate and / or compress the water (e.g., steam) through the working fluid circuit (e.g., through heat exchangers) to establish a heat exchange relationship between the water and another fluid (e.g., cooling fluid, air, brine, etc.) directed across a heat exchanger of the working fluid circuit. Additionally or alternatively, the HVAC&R system may be configured to circulate and / or compress the water (e.g., steam) to establish a heat exchange relationship between the water and another flow of water. In some embodiments in which the compressor is configured to circulate water through the working fluid circuit as the working fluid, vaporized water (e.g., steam) may be directed from an evaporator to the compressor, thereby enabling the compressor to compress the steam before delivering the steam to a condenser. The compressor may be coupled to a motor configured to drive or power the compressor. For example, the motor may include a rotor shaft, which may be supported by a bearing assembly, within a motor housing. By rotating the rotor shaft, the motor enables rotation of an impeller of the compressor coupled to the rotor shaft to drive the working fluid (e.g., water) within the working fluid circuit.

[0022] To adequately drive the water through the working fluid circuit at a desired operating pressure and / or flow rate, the compressor may be configured to operate at high speeds during an operative mode of the compressor. As a result, the rotor shaft may generate friction against certain types of sealing elements within the compressor and / or motor, thereby causing certain existingsealing systems to wear prematurely, which may undesirably lead to frequent and / or expensive replacement of the sealing systems. Furthermore, during an idle or standby mode of the compressor, working fluid (e.g., water, steam) remaining within the compressor may condense, thereby creating a negative pressure or vacuum on a compression side (e.g., impeller side, compression cavity, working fluid flow path, impeller cavity) of the compressor. In certain cases, air (e.g., non-condensable air) from and / or within the motor may be drawn into (e.g., entrained into) the compression side of the compressor by the negative pressure vacuum. Typically, non- condensable air on the compression side of the compressor is purged before the compressor is operated again (e.g., after the idle or standby mode), which causes a reduction in efficiency. Additionally, the air may include oxygen, which may cause wear and degradation (e.g., oxidation as a result of the oxygen within the entrained air) of components of the compressor, which is undesirable. Further still, in some conditions, condensed working fluid (e.g., liquid water) on the compression side (e.g., within the impeller cavity) of the compressor may flow into the motor housing, thereby causing wear and degradation on components of the motor, which may also be undesirable.

[0023] Accordingly, embodiments of the present disclosure are directed toward a sealing system (e.g., inflatable seal system) having an inflatable sealing element (e.g., inflatable seal, inflatable sealing ring, annular seal) that enables operation of the compressor at high speeds during an operative mode of the compressor and is also configured to limit (e.g., reduce, block, prevent) an amount of fluid migration between different portions of the compressor (e.g., during an idle or standby mode of the compressor). In particular, the sealing system is configured to block flow of fluid (e.g., air) from the motor cavity to a compression side (e.g., impeller side, impeller cavity, compression cavity, working fluid flow path) of the compressor and to block flow of working fluid (e.g., condensed working fluid, water, steam) from the compression side to the motor cavity during an idle or standby mode (e.g., non-operating mode) of the compressor. For example, present embodiments are directed to a sealing system having a sealing element (e.g., inflatable sealing element, inflatable seal, inflatable sealing ring, annular seal) configured to be disposed about (e.g., encircle) a shaft (e.g., motor shaft, rotor shaft) of the compressor. The sealing element is also configured to be fluidly coupled to a pressurized fluid source and to transition between a deflated configuration (e.g., resting configuration, disengaged configuration, deactivated configuration), in which the sealing element is not engaged with the rotor shaft, and an inflated configuration (e.g.,engaged configuration, sealing configuration, activated configuration), in which the sealing element is engaged with (e.g., contacts, abuts) an outer surface of the rotor shaft to provide a fluid seal between the motor cavity and the compression side (e.g., compression cavity, impeller cavity) of the compressor.

[0024] For example, during an idle or standby mode of the compressor (e.g., during a nonoperative mode of the compressor), a pressurized fluid (e.g., water, gas buffer, steam buffer, air) may be directed through a conduit and into the sealing element to transition the sealing element from the deflated configuration (e.g., resting configuration, resting state, disengaged configuration) to the inflated configuration (e.g., engaged configuration, sealing configuration). As the pressurized fluid is directed into the sealing element (e.g., into an annulus and / or annular cavity of the sealing element), the sealing element may expand (e.g., radially expand, such that the sealing element transitions to the inflated configuration). Expansion of the sealing element may cause at least one side (e.g., radially inward side, radially inward surface) of the sealing element to engage with an outer surface of the rotor shaft to provide a fluid seal between the motor cavity and the compression side. As noted above, during an idle mode of the compressor, working fluid (e.g., water, steam) may condense within the compressor (e.g., on the compression side), and in certain cases, may naturally tend to migrate toward the motor housing (e.g., motor cavity), which may be undesirable. Additionally, as the working fluid condenses, a negative pressure and / or vacuum may be created on the compression side, which may cause non-condensable air from the motor to be drawn toward the compression side by the negative pressure and / or vacuum generated on the compressor side of the system via the condensing steam, which may also be undesirable. Accordingly, during an idle mode of the compressor, pressurized fluid may be directed into the sealing element (e.g., into an annular cavity of the sealing element) to transition the sealing element to the inflated configuration, thereby enabling the sealing element to engage with (e.g., contact) the outer surface of the rotor shaft. In this way, migration of condensed working fluid (e.g., water, steam) from the compression side of the compressor to the motor housing and migration of non- condensable air from the motor cavity to the compression side during an idle mode of the compressor may be reduced, thereby reducing costs associated with wear and degradation of components of the HVAC&R system (e.g., heat pump). Additionally, the reduction of air (e.g., non-condensable gas) migration from the motor cavity to the compression side may substantially reduce a demand for purge operations prior to subsequent operation of the compressor. In thisway, the presently disclosed techniques also enable increased efficiency of HVAC&R systems having the compressor.

[0025] During an operative mode (e.g., active operating mode) of the compressor, the pressurized fluid may no longer be directed toward (e.g., into) the sealing element, thereby enabling the sealing element to transition from the inflated configuration (e.g., engaged configuration, sealing configuration) to the deflated configuration (e.g., resting state, resting configuration, disengaged configuration). For example, when pressurized fluid is no longer directed toward and / or into the sealing element, an inherent elasticity and / or internal stiffness (e.g., material elasticity, material stiffness) of the sealing element may cause the sealing element to deflate and / or return to the deflated configuration such that the sealing element no longer engages with (e.g., contacts) the outer surface of the rotor shaft. As the sealing element returns to the deflated configuration, the radially inward surface of the sealing element may disengage from the rotor shaft, thereby enabling increased speeds of the rotor shaft as an amount of interference (e.g., friction) from the sealing element is reduced via non-contact between the sealing element and the rotor shaft. Thus, in accordance with the present techniques, by employing a sealing system having a sealing element configured to transition between an inflated configuration and a deflated configuration based on an operating mode of the compressor, fluid migration between various components of the compressor may be reduced, while increased speeds of the rotor shaft may be achieved.

[0026] Turning now to the drawings, FIG. 1 is a perspective view of an embodiment of an environment for a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system 10 in a building 12 for a typical commercial setting. The HVAC&R system 10 may include a vapor compression system 14 (e.g., chiller system, heat pump system) that supplies a chilled liquid, which may be used to cool the building 12. The HVAC&R system 10 may also include a boiler 16 to supply warm liquid to heat the building 12 and an air distribution system which circulates air through the building 12. The air distribution system can also include an air return duct 18, an air supply duct 20, and / or an air handler 22. In some embodiments, the air handler 22 may include a heat exchanger that is connected to the boiler 16 and the vapor compression system 14 by conduits 24. The heat exchanger in the air handler 22 may receive either heated liquid from the boiler 16 or chilled liquid from the vapor compression system 14, depending on the mode of operation of the HVAC&R system 10. The HVAC&R system 10 is shown with a separate airhandler on each floor of building 12, but in other embodiments, the HVAC&R system 10 may include air handlers 22 and / or other components that may be shared between or among floors.

[0027] FIGS. 2 and 3 illustrate embodiments of the vapor compression system 14 that can be used in the HVAC&R system 10. The vapor compression system 14 may circulate a working fluid through a circuit starting with a compressor 32. The circuit may also include a condenser 34 (e.g., first heat exchanger), an expansion valve(s) or device(s) 36, and a liquid chiller or an evaporator 38 (e.g., second heat exchanger). The vapor compression system 14 may further include a control panel 40 that has 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 may be used as working fluids in the vapor compression system 14 are water vapor, R-718, hydrofluorocarbon (HFC) based working fluids, for example, R-410A, R-407, R-134a, hydrofluoro olefin (HFO), “natural” working fluids like ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbon based working fluids, or any other suitable working fluid.

[0028] In some embodiments, the vapor compression system 14 may use one or more of a variable speed drive (VSDs) 52, a motor 50, the compressor 32, the condenser 34, the expansion valve or device 36, and / or the evaporator 38. The motor 50 may drive the compressor 32 and may be powered by a variable speed drive (VSD) 52. The VSD 52 receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor 50. In other embodiments, the motor 50 may be powered directly from an AC or direct current (DC) power source. The motor 50 may 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.

[0029] The compressor 32 is configured to compress a working fluid vapor and delivers the vapor to the condenser 34 through a discharge passage. In some embodiments, the compressor 32 may be a centrifugal compressor. The working fluid vapor delivered by the compressor 32 to the condenser 34 may transfer heat to a cooling fluid (e.g., water or air) in the condenser 34. The working fluid vapor may condense to a working fluid liquid in the condenser 34 as a result of thermal heat transfer with the cooling fluid. The liquid working fluid from the condenser 34 may flow through the expansion device 36 to the evaporator 38. In the illustrated embodiment of FIG.3, the condenser 34 is water cooled and includes a tube bundle 54 connected to a cooling tower 56, which supplies the cooling fluid to the condenser 34.

[0030] The liquid working fluid delivered to the evaporator 38 may absorb heat from a conditioning fluid, which may or may not be the same cooling fluid used in the condenser 34. The liquid working fluid in the evaporator 38 may undergo a phase change from the liquid working fluid to a vapor working fluid. As shown in the illustrated embodiment of FIG. 3, the evaporator 38 may include a tube bundle 58 having a supply line 60S and a return line 60R connected to a cooling load 62. The conditioning fluid of the evaporator 38 (e.g., water, ethylene glycol, calcium chloride brine, sodium chloride brine, or any other suitable fluid) enters the evaporator 38 via return line 60R and exits the evaporator 38 via supply line 60S. The evaporator 38 may reduce the temperature of the conditioning fluid in the tube bundle 58 via thermal 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 any case, the vapor working fluid exits the evaporator 38 and returns to the compressor 32 via a suction line or conduit to complete the cycle.

[0031] FIG. 4 is a schematic of the vapor compression system 14 with an intermediate circuit 64 incorporated between the condenser 34 and the expansion device 36. The intermediate circuit 64 may have an inlet line 68 that is directly fluidly connected to the condenser 34. In other embodiments, the inlet line 68 may be indirectly fluidly coupled to the condenser 34. As shown in the illustrated embodiment of FIG. 4, the inlet line 68 includes a first expansion device 66 positioned upstream of an intermediate vessel 70. In some embodiments, the intermediate vessel 70 may be a flash tank (e.g., a flash intercooler, economizer). In other embodiments, the intermediate vessel 70 may be configured as a heat exchanger or a "surface economizer." In the illustrated embodiment of FIG. 4, the intermediate vessel 70 is used as a flash tank, and the first expansion device 66 is configured to lower the pressure of (e.g., expand) the liquid working fluid received from the condenser 34. During the expansion process, a portion of the liquid working fluid may vaporize, and thus, the intermediate vessel 70 may be used to separate the vapor from the liquid received from the first expansion device 66.

[0032] Additionally, the intermediate vessel 70 may provide for further expansion of the liquid working fluid due to a pressure drop experienced by the liquid working fluid upon entering the intermediate vessel 70 (e.g., due to a rapid increase in volume experienced upon flowing into theintermediate vessel 70). The vapor in the intermediate vessel 70 may be drawn by the compressor 32 through a suction line 74 of the compressor 32. In other embodiments, the vapor in the intermediate vessel may be drawn to an intermediate stage of the compressor 32 (e.g., not the suction stage). The liquid that collects in the intermediate vessel 70 may be at a lower enthalpy than the liquid working fluid exiting the condenser 34 due to the expansion via the expansion device 66 and / or the intermediate vessel 70. The liquid from intermediate vessel 70 may then flow in line 72 through a second expansion device 36 and to the evaporator 38.

[0033] It should be appreciated that any of the features described herein may be incorporated with the vapor compression system 14 or any other suitable HVAC&R systems, such as heat pumps. For example, the present techniques may be incorporated with any HVAC&R system having a compressor, such as the compressor 32. The discussion below describes the present techniques incorporated with embodiments of the compressor 32 configured as a single stage compressor. However, it should be noted that the systems and methods described herein may be incorporated with other embodiments of the compressor 32 and HVAC&R system 10. Further, the present techniques may be incorporated with HVAC&R systems that utilize any suitable working fluid, such as water.

[0034] In accordance with the present techniques, motors having rotating components, such as the motor 50 for the compressor 32, may utilize sealing systems to enable operation of the motor 50 and the compressor 32 (e.g., at high speeds) while enabling a reduction in an amount of fluid migration between the motor cavity of the motor 50 and a compression side (e.g., impeller side, compression cavity, working fluid flow path, compression chamber, impeller cavity) of the compressor 32 during an operative mode and / or during an idle or standby mode of the compressor 32. For example, embodiments of the sealing system disclosed herein are configured to block flow of air from the motor cavity of the motor 50 to the compression cavity of the compressor 32 and to block flow of condensed working fluid from the compression cavity of the compressor 32 to the motor cavity of the motor 50.

[0035] To facilitate the following discussion, FIG. 5 is a cross-sectional side view of an embodiment of a compressor system 100 (e.g., compression section) of an embodiment of the vapor compression system 14 (e.g., heat pump system) having a compressor, such as the compressor 32, and a motor, such as the motor 50, of the vapor compression system 14. In thepresent embodiment, the compressor system 100 includes a housing 101 (e.g., compressor housing, motor housing, enclosure) configured to contain, enclose, and / or house components of the compressor system 100, such as the motor 50. In some embodiments, the housing 101 may include a compressor housing portion 102 configured to enclose components of the compressor 32 and a motor housing portion 104 configured to enclose components of the motor 50, and the compressor housing portion 102 and the motor housing portion 104 may be coupled (e.g., mounted, secured) to one another. A rotor shaft 106 may be disposed within an interior volume of the motor housing portion 104 and may be coupled to the compressor 32 and configured to drive operation of the compressor 32 as the motor 50 is operated. For example, the rotor shaft 106 may be coupled to an impeller 108 of the compressor 32 via a rotor 33 (e.g., shaft). As the motor 50 is operated, the rotor shaft 106 may be driven into rotation to thereby rotate the impeller 108 of the compressor 32 and enable the compressor 32 to compress a working fluid (e.g., water, steam), such as to a desired pressure, before directing the working fluid out of a volute portion 110 of the compressor 32 and toward downstream components of the vapor compression system 14 (e.g., a heat exchanger, such as a condenser and / or an evaporator). For example, in embodiments in which the compressor 32 is configured to circulate water as a working fluid, vaporized water (e.g., steam) may be directed from the evaporator 38 to the compressor 32, thereby enabling the compressor 32 to compress the steam before delivering the steam to the condenser 34.

[0036] As illustrated, the rotor shaft 106 may be a cylindrical component having a length extending along an axial or longitudinal axis or direction 200, a radius extending along a radial axis or direction 202, and a circumference extending along a circumferential axis or direction 204. The rotor shaft 106 may be supported by one or more bearing assemblies 112. In some embodiments, one or more the bearing assemblies 112 are configured to enable the rotor shaft 106 to rotate about the longitudinal axis 200 relative to the housing 101 to perform work, such as compressing the working fluid (e.g., water, steam). The bearing assemblies 112 may include any suitable bearings circumferentially disposed around the rotor shaft 106, such as ball bearings, sleeve bearings, roller bearings, and so forth. Additionally or alternatively, some embodiments of the compressor system 100 may include one or more bearing assemblies 112 (e.g., a thrust bearing) configured to regulate a position (e.g., axial position) of the rotor shaft 106 along the longitudinal axis 200.

[0037] In certain embodiments, the compressor system 100 of the vapor compression system 14 may include a sealing system 120 (e.g., sealing assembly, inflatable sealing assembly) configured to enable rotation, such as high speed rotation, of the rotor shaft 106, and thus the compressor 32, during an operative mode (e.g., active operating mode, operational state, active state, compression mode) of the compressor 32. The sealing system 120 may also be configured to limit and / or reduce fluid migration between the motor cavity of the motor 50 (e.g., a cavity defined by the motor housing portion 104) and the compression side (e.g., impeller cavity) of the compressor 32 (e.g., between the compressor housing portion 102 and the motor housing portion 104) during an idle or standby mode (e.g., non-operating mode, inoperative mode, inactive state, non-compressing state) of the compressor 32. For example, the sealing system 120 may include a sealing element 122 (e.g., inflatable sealing element, sealing ring, annular seal, inflatable sealing ring) disposed within an annular chamber of the housing 101, and the sealing element 122 may be configured to transition between a deflated configuration (e.g., resting state, disengaged configuration, contracted configuration, deactivated configuration) and inflated configuration (e.g., engaged configuration, sealing configuration, expanded configuration, activated configuration). In some embodiments, the particular configuration of the sealing element 122 may be based on an operating mode of the compressor 32, as described in greater detail below.

[0038] The sealing element 122 may be fluidly coupled to a pressurized fluid source 124 (e.g., inflation medium source, steam buffer source) that is configured to direct a pressurized fluid 126 (e.g., inflation medium, water, steam, air) via a conduit 128 into the sealing element 122. For example, flow of the pressurized fluid 126 from the pressurized fluid source 124 into the sealing element 122 may be regulated (e.g., initiated, suspended, controlled, adjusted) based on an operating mode of the compressor 32. For example, during an idle or standby mode of the compressor 32, the pressurized fluid source 124 may be controlled (e.g., via a controller) to direct the pressurized fluid 126 into the sealing element 122 (e.g., into a cavity, such as an annular cavity, of the sealing element 122), thereby enabling the sealing element 122 to inflate and / or expand (e.g., transition to the inflated configuration, expand radially outward). In this way, at least a portion (e.g., a surface) of the sealing element 122 may be biased against an outer surface 130 of the rotor shaft 106 to create a sealing interface therebetween, thereby restricting and / or sealing a flow path between the compressor housing portion 102 and the motor housing portion 104 and limiting and / or reducing fluid migration between the compressor housing portion 102 and themotor housing portion 104 (e.g., during an idle or standby mode of the compressor 32). Conversely, during an operative mode of the compressor 32, the pressurized fluid source 124 (e.g., a valve) may be controlled to suspend flow of the pressurized fluid 126 into the sealing element 122. As a result, the sealing element 122 may deflate (e.g., transition to the deflated configuration due to a material and / or inherent elasticity of the sealing element 122 and / or due to a material and / or internal stiffness of the sealing element 122), such that the sealing element 122 may no longer biased against the outer surface 130 of the rotor shaft 106. In this way, increased speeds of the rotor shaft 106 may be achieved due to the reduced amount of friction between the sealing element 122 and the rotor shaft 106 (e.g., during an operative mode of the compressor 32).

[0039] For example, FIG. 6 illustrates a perspective view of an embodiment of the sealing element 122. As illustrated, the sealing element 122 includes a first side 132 (e.g., first surface, radially inward surface, inner diameter) configured to engage with the outer surface 130 of the rotor shaft 106 when the sealing element 122 is in the inflated configuration (e.g., during an idle or standby mode of the compressor 32), and one or more additional sides 134 (e.g.., outer diameter, axial surfaces, first axial surface, second axial surface) configured to engage with one or components of the housing 101 (e.g., engage with inner housing walls of the housing 101 that define the annular chamber in which the sealing element 122 is disposed). In certain embodiments, each of the one or more additional sides 134 may be configured to engage with (e.g., abut) the inner housing walls that define the annular chamber in which the sealing element 122 is disposed regardless of whether the compressor 32 is in an operative mode or an idle mode, as discussed in greater detail below. Each of the first side 132 and the one or more additional sides 134 may collectively define (e.g., enclose) an internal volume 138 (e.g., annular chamber, annular volume, internal annulus, annular cavity) of the sealing element 122, and the internal volume 138 may be configured to receive the pressurized fluid 126 from the pressurized fluid source 124 via the conduit 128.

[0040] In certain embodiments, the first side 132 may include a toothed surface 133 for limiting fluid (e.g., lubricant) flow from the bearing assemblies 112, for limiting fluid (e.g., noncondensable air) migration from the motor housing portion 104 to the compressor housing portion 102, and / or for limiting fluid (e.g., condensed working fluid, such as water) migration from the compressor housing portion 102 to the motor housing portion 104 when the sealing element 122 is in the inflated configuration (e.g., during an idle mode of the compressor 32). The sealingelement 122 may be formed of a flexible material, such as polytetrafluoroethylene (PTFE), rubber, or another suitable material that enables the sealing element 122 to expand (e.g., inflate) upon receiving the pressurized fluid 126 from the pressurized fluid source 124. However, it should be noted that the sealing element 122 may be formed of a flexible material that has an inherent elasticity (e.g., material elasticity) and / or internal stiffness (e.g., material stiffness) that causes the sealing element 122 to transition back to the deflated configuration (e.g., resting configuration, disengaged configuration) when pressurized fluid 126 is not directed into the sealing element 122. That is, during a resting state of the sealing system 120 (e.g., during a state in which pressurized fluid 126 is not directed into the internal volume 138 of the sealing element 122, during an operative mode of the compressor 32), the sealing element 122 may transition to the deflated configuration (e.g., disengaged configuration) such that the first side 132 of the sealing element 122 does not engage with the outer surface 130 of the rotor shaft 106.

[0041] Returning to FIG. 5, as the pressurized fluid 126 is directed into the internal volume 138 of the sealing element 122, the sealing element 122 may expand and / or inflate such that the one or more additional sides 134 engage with the inner housing walls that define the annular chamber. In certain embodiments, the inner housing walls that define the annular chamber may limit an amount of expansion of the sealing element 122 in a direction (e.g., radially outward direction) away from the outer surface 130 of the rotor shaft 106. Because the one or more additional sides 134 are limited from expanding in a direction away from the outer surface 130 of the rotor shaft 106 (e.g., via engagement of the one or more additional walls 134 with the inner housing walls that define the annular chamber), the first side 132 of the sealing element 122 may expand in a direction (e.g., radially inward direction) along the radial axis 202 toward the outer surface 130 of the rotor shaft 106 in response to the pressurized fluid 126 being directed into the internal volume 138. In this way, the first side 132 may engage with the outer surface 130 of the rotor shaft 106, thereby limiting an amount of fluid migration between the compressor housing portion 102 and the motor housing portion 104 during an idle or standby mode of the compressor 32, as discussed in greater detail below.

[0042] In certain embodiments, the sealing system 120 may also include one or more labyrinth seals 140, such as two labyrinth seals 140 positioned on opposite sides of the sealing element 122. The one or more labyrinth seals 140 may include a sealing extension that has a T-shaped crosssection with a toothed surface for limiting fluid (e.g., lubricant) flow from the bearing assemblies 112, for limiting fluid (non-condensable air) migration from the motor housing portion 104 to the compressor housing portion 102, and / or for limiting fluid (e.g., condensed working fluid, such as water or steam) migration from the compressor housing portion 102 to the motor housing portion 104.

[0043] In certain embodiments, the pressurized fluid source 124 may include a high-pressure or discharge portion of the compressor 32, an external pressurized fluid source, such as a canister or pump, or any other suitable source of fluid that is pressurized relative to a pressure of the internal volume 138 of the sealing element 122. For example, in embodiments in which the compressor 32 is configured to circulate water as a working fluid, vaporized water (e.g., steam) may be directed from an evaporator to the compressor 32, and the compressor 32 may compress the steam and discharge the steam to a condenser. A portion of the steam pressurized by the compressor 32 may be utilized as the pressurized fluid 126. In certain cases, the steam may undergo multiple stages of compression before the generated steam is sufficiently pressurized relative to the volume 138 of the sealing element 122. For example, a pressure of the steam within the compressor 32 may be below atmospheric pressure, which may be insufficient to inflate the sealing element 122 and cause the first surface 132 of the sealing element 122 to engage with the outer surface 130 of the rotor shaft 106. Accordingly, in certain embodiments, the steam may first be directed through one or more additional stages of compression, such that the steam reaches a pressure that is greater than a desired threshold pressure (e.g., pressure greater than atmospheric pressure, pressure greater than an internal pressure of the sealing element 122). In this way, present embodiments may utilize the steam to transition the sealing element 122 to the inflated configuration (e.g., engaged configuration, sealing configuration), such that the first side 132 of the sealing element 122 engages with the outer surface 130 of the rotor shaft 106 to provide a fluid seal between the compressor housing portion 102 and the motor housing portion 104 (e.g., during an idle or standby mode of the compressor 32). In other embodiments, the pressurized fluid source 124 may correspond to an external pressurized source having a pump configured to pressurize the pressurized fluid 126 to a desired pressure before directing the pressurized fluid 126 toward the sealing element 122.

[0044] In the present embodiment, the pressurized fluid 126 travels through an injection pathway 142 defined or machined into the housing 101. The injection pathway 142 may extend between the pressurized fluid source 124 and the conduit 128 fluidly coupled to the sealing element 122. For example, the pressurized fluid 126 may pass through the injection pathway 142 and through the conduit 128 to pressurize the internal volume 138 of the sealing element 122. In this way, a pressure that effectively inflates the sealing element 122 and causes the first side 132 of the sealing element 122 to engage with the outer surface 130 of the rotor shaft 106 may be selectively applied to the sealing element 122. That is, the sealing system 120 may selectively apply the pressurized fluid 126 to the sealing element 122 to cause the sealing element 122 to engage with (e.g., create a sealing engagement with) the outer surface 130 of the rotor shaft 106 (e.g., to transition the sealing element to the inflated configuration), thereby providing a fluid seal between the compressor housing portion 102 and the motor housing portion 104. In this way, fluid migration between the compressor housing portion 102 and the motor housing portion 104 may be limited and / or reduced (e.g., during an idle or standby mode of the compressor 32).

[0045] During an operative mode of the compressor 32, the rotor shaft 106 may rotate at various rotation rates or speeds about the circumferential axis 204 and relative to the housing 101 to power or drive the rotor 33, and thus the impeller 108, of the compressor 32. For example, based on control signals received from a controller panel (e.g., control panel 40) or another suitable control device or system (e.g., controller 220), the motor 50 may ramp up in rotation rate of the rotor shaft 106 from a resting state corresponding to zero revolutions per minute (RPM) to an activated state corresponding to approximately 500 RPM, 1000 RPM, 2500 RPM, 5000 RPM, and / or another suitable speed. In other words, the motor 50 may ramp up in speed of the rotor shaft 106 from a resting state corresponding to zero meters per second (m / s) to approximately 50 m / s, 75 m / s, 90 m / s, and / or another suitable speed. As noted above, in certain embodiments, the rotation rate or speed of the compressor 32 (e.g., rotation rate of the rotor shaft 106) may be dependent upon the type of working fluid (e.g., water, steam) directed through the vapor compression system 14. For example, in embodiments in which water is used as the working fluid, the compressor 32 may be configured to operate at higher rotation rates or shaft seal surface speeds (e.g., 15,000 RPM, 25,000 RPM, 45,000 RPM, 100 m / s, 115 m / s, 130 m / s) to desirably compress the water and direct the water through the vapor compression system 14. However, operating the compressor 32 at suchrotation rates and / or speeds may result in wear and degradation on components of the sealing system 120.

[0046] Accordingly, to operate the compressor 32 with a rotation rate or speed above a threshold rotation rate or threshold speed (e.g., above a design threshold rotation rate of the sealing system 120 and / or sealing element 122, above a design threshold rotation speed of the sealing system 120 and / or sealing element 122), the pressurized fluid source 124 may be selectively controlled to not direct pressurized fluid 126 through the injection pathway 142, thereby enabling the sealing element 122 to transition to the deflated configuration. In this way, the first side 132 of the sealing element 122 may no longer contact (e.g., engage with) the outer surface 130 of the rotor shaft 106, thereby enabling the rotor shaft 106, and thus the compressor 32, to rotate at higher speeds while limiting an amount of wear and degradation to the sealing element 122 (e.g., via reduced contact between the sealing element 122 and the rotor shaft 106 during rotation of the rotor shaft 106). For example, the inherent elasticity of the sealing element 122 may cause and / or enable the sealing element 122 to transition to the deflated configuration (e.g., disengaged configuration, resting configuration) when the pressurized fluid 126 is not injected into the injection pathway 142. Additionally or alternatively, in certain embodiments, the internal volume 138 of the sealing element 122 may be fluidly coupled to a vacuum pressure source 139 (e.g., vacuum pump, evaporator, low pressure section or conduit of the vapor compression system 14, vacuum pressure source below a threshold value [e.g., below atmospheric pressure]), thereby enabling application of a vacuum pressure to the sealing element 122 to facilitate transitioning of the sealing element 122 to the deflated configuration.

[0047] Thus, during a resting state of the sealing system 120 (e.g., during a period in which no pressurized fluid 126 is supplied to the internal volume 138 of the sealing element, during a period in which the pressurized fluid source 124 is controlled to block and / or stop flow of the pressurized fluid 126 into the injection pathway 142, during a period in which the vacuum pressure source 139 is operated to apply a vacuum pressure to the sealing element 122), the sealing element 122 may transition to the deflated configuration such that the first side 132 of the sealing element 122 disengages from the outer surface 130 of the rotor shaft 106. In certain embodiments, as the sealing element 122 transitions to the deflated configuration (e.g., as a result of pressurized fluid 126 no longer being directed into the sealing element 122, based on operation of the vacuum pressuresource 139, due to the inherent elasticity of the sealing element 122), the pressurized fluid 126 within the internal volume 138 of the sealing element 122 may be discharged and / or drawn along the injection pathway 142 (e.g., in an opposite direction relative to the of the pressurized fluid 126 injected into the sealing element 122). Thus, in certain embodiments (e.g., during an operative mode of the compressor 32), the injection pathway 142 may also correspond to an exit pathway 144. In certain embodiments, the conduit 128 may include a valve that enables pressurized fluid to travel out of the sealing element 122 and along the exit pathway 144 and eventually to the atmosphere via an outlet.

[0048] Conversely, upon the compressor 32 transitioning to an idle or standby mode, the pressurized fluid source 124 may be controlled (e.g., via a controller) to direct (e.g., inject) the pressurized fluid 126 into the internal volume 138 of the sealing element 122 (e.g., via the injection pathway 142 and conduit 138) such that the sealing element 122 transitions to the inflated configuration (e.g., engaged configuration, sealing configuration). In this way, the sealing element 122 may expand and / or inflate such that the first side 132 of the sealing element 122 engages with (e.g., contacts) the outer surface 130 of the rotor shaft 106 to form a fluid seal between the compressor housing portion 102 and the motor housing portion 104.

[0049] For example, in certain embodiments, water may be utilized as a working fluid, and water vapor (e.g., steam) may be utilized as the pressurized fluid 126 supplied to the compressor 32 (e.g., via the injection pathway 142) to selectively inflate the sealing element 122 (e.g., transition the sealing element 122 to the inflated configuration), thereby causing the first side 132 of the sealing element to engage with the outer surface 130 of the rotor shaft 106 during an idle mode of the compressor 32. However, presence of the pressurized fluid 126 (e.g., steam) within the housing 101 (e.g., within the motor housing portion 104) may reduce the efficiency of the motor 50 and / or increase wear and degradation on components of the motor 50. Accordingly, in certain embodiments, the compressor system 100 may have an open design (e.g., as opposed to hermetic or semi -hermetic compressor design), such that the motor 50 is vented with air and separated from the compressor 32 via the housing 101 (e.g., via the compressor housing portion 102 and the motor housing portion 104). For example, the motor housing portion 104 may be cooled by a pressurized air flow that is forced into the motor housing portion 104 (e.g., via a fan or blower), which in turn, creates a pressure rise within the motor housing portion 104. In certain embodiments, the pressurewithin the motor housing portion 104 may be maintained at a pressure slightly above atmospheric pressure (e.g., using the pressurized air from an air source).

[0050] During an idle or standby mode of the compressor 32, the rotor shaft 106 may not rotate, and a control panel (e.g., control panel 40) or other suitable controller (e.g., controller 220) may provide a signal to direct pressurized fluid 126 from the pressurized fluid source 124 through the injection pathway 142 and the conduit 128 into the internal volume 138 of the sealing element 122. In turn, the sealing element 122 may inflate and / or expand as described above such that the first side 132 of the sealing element 122 engages with the outer surface 130 of the rotor shaft 106 to provide a fluid seal between the compressor housing portion 102 and the motor housing portion 104. For example, because the rotor shaft 106 and the compressor 32 may no longer be rotating during an idle mode of the compressor 32, the saturation temperature of working fluid within the compressor 32 may decrease, which may cause working fluid vapor within the compressor 32 to condense into a working fluid liquid. For example, in embodiments in which water is used as a working fluid, as the saturation temperature of the fluid within the compressor 32 decreases due to the compressor 32 being inoperative (e.g., inactive, not rotating), water vapor (e.g., steam) may begin to condense into liquid water. As noted above, the presence of water and / or steam within the motor housing portion 104 of the housing 101 may be undesirable.

[0051] Additionally, during the idle mode of the compressor 32, as the working fluid vapor condenses (e.g., as a result of the saturation temperature of fluid within the compressor 32 decreasing), the pressure within the compressor 32 (e.g., within the compressor housing portion 102) may also decrease and a negative pressure vacuum may be created on the compression side (e.g., within the compressor housing portion 102), which may cause non-condensable air within the motor housing portion 104 to be drawn into the compressor 32 (e.g., compression side), which may also be undesirable. As such, pressurized fluid 126 may be selectively injected into the injection pathway 142 during the idle or standby mode of the compressor 32 to transition the sealing element 122 into the inflated configuration such that the first side 132 of the sealing element 122 is engaged with the outer surface 130 of the rotor shaft 106, thereby blocking condensed working fluid (e.g., liquid water) from traveling across the sealing element 122 and toward (e.g., into) the motor housing 102 and / or blocking non-condensable air from traveling across the sealing element 122 and into the compressor 32 (e.g., compression side). In this way,an amount of fluid migration from the compressor housing portion 102 to the motor housing portion 104 and / or from the motor housing portion 104 to the compressor housing portion 102 may be limited and / or reduced, thereby reducing costs associated with wear and degradation of the motor 50 and / or compressor 32.

[0052] In certain embodiments, the compressor system 100 may include one or more sensors 210 configured to detect various operating parameters and / or operating conditions of the compressor 32. For example, the one or more sensors 210 may be disposed throughout the compressor 32 and / or motor 50 (e.g., within the compressor housing portion 102 and / or the motor housing portion 104) and may be configured to detect data indicative of an operating mode of the compressor (e.g., whether the compressor 32 is in an operative mode or an idle or standby mode), a temperature, a pressure, and / or a flow rate of working fluid through the compressor 32, a rotational rate of the compressor 32 (e.g., rotational rate of an impeller of the compressor 32), and the like. The one or more sensors 210 may communicate such data to a controller 220 (e.g., control panel 40, control system, automation controller), thereby enabling the controller 220 to control operation of the pressurized fluid source 124 and / or operation of the vacuum pressure source 139 (e.g., thereby enabling the controller 220 to transition the sealing element 122 between the inflated configuration and the deflated configuration). That is, in certain embodiments, certain components of the compressor 32 may be communicatively coupled to the controller 220 (e.g., control panel 40), thereby enabling the controller 220 to control operation of the compressor 32, the sealing system 120 (e.g., sealing element 122, pressurized fluid source 124), the vacuum pressure source 139, and / or other components of the vapor compression system 14.

[0053] In certain embodiments, the controller 220 may include processing circuitry 222 (e.g., one or more microprocessors) and a memory 224. For example, the controller 220 may include non- transitory code or instructions stored in a machine-readable medium (e.g., the memory 224) that is used by the processing circuitry 222 to implement the techniques disclosed herein. The memory 224 may include volatile memory, such as read-only memory (ROM), optical drives, hard disc drives, solid-state drives, or any other non-transitory, computer-readable medium storing instructions that, when executed by the processing circuitry 222, control operation of the compressor 32 and / or the sealing system 120. The controller 220 may monitor and control operation of the sealing system 120, for example, by controlling operation of the pressurized fluidsource 124 and / or the vacuum pressure source 139. In certain embodiments, the controller 220 may control operation of the pressurized fluid source 124 and / or the vacuum pressure source 139 based on feedback received from the one or more sensors 210. For example, upon receiving sensor data indicative of the compressor 32 transitioning to an idle or standby mode, the controller 220 may control (e.g., activate) the pressurized fluid source 124 to direct the pressurized fluid 126 toward the sealing element 122 of the sealing system 120. In certain embodiments, the one or more sensors 210 may be configured to capture data indicative of a pressure within the compressor 32. For example, upon determining that the pressure within the compressor 32 is below a threshold pressure (e.g., below 1 atmosphere), the controller 220 may send a control signal to the pressurized fluid source 124, thereby causing the pressurized fluid source 124 to inject pressurized fluid 126 into the injection pathway 142 and into the sealing element 122.

[0054] Conversely, upon detecting that the compressor 32 is in an operative mode (e.g., via data from the one or more sensors 210), the controller 220 may control (e.g., deactivate) the pressurized fluid source 124, such that the pressurized fluid 126 is no longer directed through the injection pathway 142 and toward the sealing element 122. Additionally or alternatively, upon detecting that the compressor 32 is in an operative mode, the controller 220 may control (e.g., activate) the vacuum pressure source 139 to facilitate transitioning of the sealing element 122 from the inflated configuration to the deflated configuration. That is, the controller 220 may control operation of the pressurized fluid source 124 and / or the vacuum pressure source 139 to selectively transition the sealing element 122 between the inflated configuration and the deflated configuration. In this way, operation of the compressor 32 at high speeds may be achievable, while an amount of fluid migration between the compressor 32 and the motor cavity of the motor 50 (e.g., between the compressor housing portion 102 and the motor housing portion 104) is limited. It should be appreciated that in certain embodiments, the controller 220 may control operation of the sealing system 120 based on a manual input provided via an operator associated with the compressor 32.

[0055] FIG. 7 is a cross-sectional side view of a portion of the compressor system 100, taken within dashed line 5-5 of FIG. 5, illustrating an embodiment of the sealing system 120. As shown in FIG. 7, the sealing element 122 is disposed within an annular chamber 146 defined between walls (e.g., inner housing walls) of the housing 101 and the outer surface 130 of the rotor shaft 106. In certain embodiments, the housing 101 (e.g., inner housing walls) may be made of asuitably rigid material (e.g., aluminum, steel, and the like) such that as the one or more additional sides 134 of the sealing element 122 engage with the inner housing walls, the sealing element 122 may only expand in a radially inward direction toward the outer surface 130 of the rotor shaft 106, as discussed above.

[0056] In certain embodiments, a sleeve 148 may be positioned about the rotor shaft 106, and the sealing element 122 may engage with the sleeve 148 to limit fluid migration across the sealing element 122 during an idle mode of the compressor 32. However, it should be noted that in certain embodiments, the sleeve 148 may be omitted and the sealing element 122 may be configured to directly contact the outer surface 130 of the rotor shaft 106 during the idle mode of the compressor 32 and / or disengage from the outer surface 130 of the rotor shaft 106 during an operative mode of the compressor 32 (e.g., due to the inherent elasticity of the sealing element 122, due to operation of the vacuum pressure source 139). As noted above, the first side 132 of the sealing element 122 may include a toothed surface 133 formed of a flexible material that enables the first side 132 of the sealing element 122 to be biased against the sleeve 148 (or the outer surface 130 of the shaft 106). As such, when the rotor shaft 106 is at rest or still, the toothed surface 133 of the first side 132 of the sealing element 122 applies force to the sleeve 148, thus limiting an amount of fluid migration from the compressor housing portion 102 to the motor housing portion 104 and / or from the motor housing portion 104 to the compressor housing portion 102.

[0057] As set forth above, the present disclosure may provide one or more technical effects useful in operating compressors that are configured to circulate water as a working fluid. Embodiments of the disclosure may include a sealing element configured to transition between a first configuration during an operative mode of a compressor and a second configuration during an idle or standby mode of the compressor. For example, during an idle mode of the compressor, the sealing element may be configured to receive pressurized fluid from a pressurized fluid source such that the sealing element expands to the second configuration. In the second configuration, a side of the sealing element may engage with an outer surface of a rotor shaft, thereby limiting an amount of fluid migration from a motor housing into the compressor and from the compressor into the motor housing. In this way, wear and degradation on components of both the compressor and the motor may be reduced, thereby decreasing maintenance and repair costs. During an operative mode of the compressor, pressurized fluid may not be directed into the sealing element, and theinherent elasticity of the sealing element may enable the sealing element to disengage from the outer surface of the rotor shaft. In this way, the compressor may be operated at increased speeds, thereby enabling the compressor to effectively compress the water as a working fluid. The technical effects and technical problems in the specification are examples and are not limiting. It should be noted that the embodiments described in the specification may have other technical effects and can solve other technical problems.

[0058] While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode of carrying out the disclosure, or those unrelated to enabling the claimed disclosure). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.

Claims

CLAIMS:

1. A compressor system, comprising: a housing comprising an impeller disposed therein; a motor disposed within the housing, wherein the motor comprises a rotor shaft coupled to the impeller, and the motor is configured to drive rotation of the rotor shaft and the impeller; and a sealing system disposed within the housing, wherein the sealing system comprises a sealing element circumferentially disposed around the rotor shaft and configured to bias against a surface of the rotor shaft in a first configuration, wherein the housing comprises an injection pathway formed therein, and the injection pathway is configured to direct a pressurized fluid into the sealing element to maintain the sealing element in the first configuration.

2. The compressor system of claim 1, comprising a controller configured to control operation of a pressurized fluid source to direct the pressurized fluid to the injection pathway during an idle mode of the compressor system.

3. The compressor system of claim 2, wherein the controller is configured to control operation of the pressurized fluid source to suspend supply of the pressurized fluid to the injection pathway during an active operating mode of the compressor system.

4. The compressor system of claim 3, wherein the sealing element is configured to transition to a second configuration during the active operating mode of the compressor system, wherein, in the second configuration, the sealing element is configured to disengage from the surface of the rotor shaft.

5. The compressor system of claim 4, wherein the sealing element comprises an inflatable sealing element, the first configuration corresponds to an inflated configuration, and the second configuration corresponds to a deflated configuration.

6. The compressor system of any of claims 1 to 5, wherein the sealing element comprises a flexible material, and wherein the flexible material is configured to transition the sealing element to a second configuration during a resting state of the sealing system, wherein, in the second configuration, the sealing element is configured to disengage from the surface of the rotor shaft.

7. The compressor system of claim 6, wherein during the resting state of the sealing system, the injection pathway does not direct the pressurized fluid into the sealing element.

8. The compressor system of any of claims 1 to 7, wherein the sealing element comprises a first side configured to engage with the outer surface of the rotor shaft, and one or more additional sides configured to engage with one or more inner walls of the housing, wherein the first side and the one or more additional sides collectively define an interior volume of the sealing element.

9. The compressor system of any of claims 1 to 8, wherein the housing defines a compressor housing portion and a motor housing portion, the impeller is disposed within the compressor housing portion, the motor is disposed within the motor housing portion, and the motor housing portion is configured to receive and direct a cooling air flow therethrough.

10. The compressor system of claim 9, wherein the sealing element is configured to create a sealing engagement with the surface of the rotor shaft in the first configuration, and the sealing element is configured to block fluid migration between the compressor housing portion and the motor housing portion in the first configuration.

11. A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising: a compressor configured to compress a working fluid and circulate the working fluid through a working fluid circuit; a motor coupled to the compressor via a rotor shaft and configured to drive operation of the compressor via rotation of the rotor shaft; anda sealing system configured to limit fluid migration between the motor and the compressor, wherein the sealing system comprises a sealing element configured to receive a pressurized fluid to transition the sealing element from a first configuration to a second configuration based on operation of a pressurized fluid source fluidly coupled to the sealing element, wherein a side of the sealing element is configured to engage with a surface of the rotor shaft in the second configuration in response to activation of the pressurized fluid source, and wherein the side of the sealing element is configured to disengage from the surface of the rotor shaft in the first configuration in response to deactivation of the pressurized fluid source.

12. The HVAC&R system of claim 11, wherein the working fluid is water, the HVAC&R system comprises an evaporator disposed along the working fluid circuit, the evaporator is configured to place the water in a heat exchange relationship to generate steam, and the compressor is configured to direct a portion of the steam toward the pressurized fluid source to be used as the pressurized fluid.

13. The HVAC&R system of claim 12, wherein the compressor is configured to pressurize the steam via one or more stages of compression before directing the steam to the pressurized fluid source.

14. The HVAC&R system of any of claims 11 to 13, wherein the sealing element is an inflatable sealing element, the first configuration is a deflated configuration, and the second configuration is an inflated configuration.

15. The HVAC&R system of claim 14, wherein the sealing system is configured to: control the pressurized fluid source to direct the pressurized fluid toward the sealing element during an idle mode of the compressor to transition the sealing element to the inflated configuration; and control the pressurized fluid source to not direct the pressurized fluid toward the sealing element during an active operative mode of the compressor to transition the sealing element to the deflated configuration.

16. A sealing system for a motor of a compressor, comprising: a sealing element circumferentially disposed about a rotor shaft of the motor and configured to transition between a delated configuration and an inflated configuration, wherein the sealing element comprises a surface configured to: disengage from an outer surface of the rotor shaft in the deflated configuration; and contact the outer surface of the rotor shaft in the inflated configuration; a pressurized fluid source configured to provide a pressurized fluid, wherein the sealing element is configured to transition from the deflated configuration to the inflated configuration in response to the pressurized fluid source providing the pressurized fluid; and a controller configured to control operation of the pressurized fluid source to transition the sealing element between the deflated configuration and the inflated configuration in response to a detected operational state of the compressor.

17. The sealing system of claim 16, wherein the controller is configured to: initiate the operation of the pressurized fluid source to transition the sealing element from the deflated configuration to the inflated configuration based on the detected operational state of the compressor corresponding to an idle mode; and suspend the operation of the pressurized fluid source to transition the sealing element from the inflated configuration to the deflated configuration based on the detected operational state of the compressor corresponding to an operative mode.

18. The sealing system of claim 17, wherein the sealing system is configured to: limit a first amount of fluid migration from the motor to the compressor during the idle mode of the compressor; and limit a second amount of fluid migration from the compressor to the motor during the idle mode of the compressor.

19. The sealing system of any of claims 16 to 18, comprising one or more sensors configured to detect data indicative of an operating mode of the compressor, wherein the controller is configured to control the operation of the pressurized fluid source based on the data from the one or more sensors.

20. The sealing system of claim 19, wherein the controller is configured to: initiate the operation of the pressurized fluid source to transition the sealing element to the inflated configuration based on the data from the one or more sensors indicating that the compressor is in an idle mode; and stop the operation of the pressurized fluid source to transition the sealing element to the deflated configuration based on the data from the one or more sensors indicating that the compressor is in an operative mode.

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