Lubricant diversion system for HVAC&r system

Abstract

A compressor system includes a housing having an impeller disposed therein, where the impeller is configured to rotate within an impeller cavity of the housing to compress a working fluid, 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 includes a bearing disposed circumferentially about the rotor shaft, where the bearing is configured to receive a lubricant from a lubricant source to facilitate rotation of the rotor shaft, and a lubricant diversion system configured to divert the lubricant away from the impeller cavity. The lubricant diversion system includes a seal configured to block flow of the lubricant into the impeller cavity and a balance piston coupled to the impeller, where the balance piston is configured to divert the lubricant away from the seal.

Description

LUBRICANT DIVERSION 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 / 522,641, entitled “A COMPRESSOR WITH OIL DIVERSION FEATURES,” filed June 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. HVAC&R systems typically circulate 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, an 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.

[0004] In some applications, a motor that powers a compressor may include rotating components that operate to rotate an impeller of the compressor, thereby enabling the compressor to compress the working fluid and deliver the working fluid to other components of the vapor compression system. In many applications, a lubricant, such as oil, may be directed through various flow paths to lubricate components within the motor and / or compressor. Unfortunately, lubricant within the compressor may escape from a desired flow path and may inadvertently flowto other areas of the compressor (e g., a working fluid flow path), which may cause reductions in efficiency and / or a useful life of the compressor and / or motor.SUMMARY

[0005] 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.

[0006] In an embodiment, a compressor system includes a housing having an impeller disposed therein, where the impeller is configured to rotate within an impeller cavity of the housing to compress a working fluid, 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 includes a bearing disposed circumferentially about the rotor shaft, where the bearing is configured to receive a lubricant from a lubricant source to facilitate rotation of the rotor shaft, and a lubricant diversion system configured to divert the lubricant away from the impeller cavity. The lubricant diversion system includes a seal configured to block flow of the lubricant into the impeller cavity and a balance piston coupled to the impeller, where the balance piston is configured to divert the lubricant away from the seal.

[0007] In an embodiment, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a compressor comprising an impeller configured to rotate within a compression cavity to compress a working fluid and to 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 lubricant diversion system configured to block flow of a lubricant into the compression cavity. The lubricant diversion system includes a balance piston having a wall portion that at least partially defines a chamber configured to capture the lubricant, and a seal having a sealing portion configured to engage with the wall portion, where the balance piston is configured to rotate with the impeller and to direct the lubricant within the chamber to flow away from the seal.

[0008] In an embodiment, a lubricant diversion system for a compressor system includes a balance piston coupled to an impeller of the compressor system. The balance piston includes a wall portion configured to extend in an axial direction of the compressor system, and a cavity at least partially defined by the wall portion, where the cavity is configured to receive lubricant from a bearing of the compressor system. The lubricant diversion system also includes a seal configured to abut the wall portion and block flow of the lubricant toward the impeller, where the balance piston is configured to rotate with the impeller during operation of the compressor system and to divert the lubricant away from the seal.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which:

[0010] 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;

[0011] FIG. 2 is a perspective view of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0012] FIG. 3 is a schematic of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0013] FIG. 4 is a schematic of an embodiment of a vapor compression system, in accordance with an aspect of the present disclosure;

[0014] FIG. 5 is a cross-sectional side view of an embodiment of a compressor system of a vapor compression system, illustrating a motor and a lubricant diversion system of the compressor system, in accordance with an aspect of the present disclosure;

[0015] FIG. 6 is a cross-sectional side view of an embodiment of the lubricant diversion system of FIG. 5, in accordance with an aspect of the present disclosure; and

[0016] FIG. 7 is a cross-sectional side view of an embodiment of a lubricant diversion system of a compressor system, in accordance with an aspect of the present disclosure.DETAILED DESCRIPTION

[0017] 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.

[0018] 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.

[0019] 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 is within + / - 5%, within + / - 4%, within + / - 3%, within + / - 2%, within + / - 1%, or evencloser, 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.

[0020] 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, such as demands within a building, home, or other suitable structure. For example, the HVAC&R system may include a vapor compression system (e.g., chiller system, heat pump system) that transfers thermal energy between a working fluid (e g., refrigerant, heat transfer fluid) and a fluid to be conditioned (e g., air, water, brine). In some embodiments, the working fluid and the fluid to be conditioned may be the same fluid (e.g., water). 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 conduit 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 several controllable features or components, such as valves, expansion devices, a coil fan, a condenser pump, and / or an evaporator pump. The vapor compression system may include a controller configured to determine the mode of operation of the vapor compression system and to control the valves, expansion devices, pumps, and fan 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 a flow of working fluid through the vapor compression circuit in different directions for different operating modes. In other embodiments, the working fluid may flow through the vapor compression circuit in the same direction during multiple (e.g., all) modes of operation.

[0021] 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 be related to one or more characteristics 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 pressure conditions at a suction inlet of the compressor, and / or working fluid temperature and pressure conditions at a discharge outlet of the compressor.

[0022] The compressor may include a compressing member (e.g., an impeller) configured to pressurize a working fluid in an impeller cavity. The compressor (e.g., the impeller, an impeller shaft) may be coupled to a motor (e.g., rotor shaft) configured to drive or power the compressor. For example, the motor may include a rotor shaft supported by one or more bearings assemblies (e g., lubricant bearing assembly) within a motor housing, and the rotor shaft may be coupled to the impeller. By rotating the rotor shaft, the motor enables rotation of the compressing member (e.g., the impeller) of the compressor coupled to the rotor shaft to drive the working fluid through the vapor compression circuit. In certain vapor compression systems, a lubricant (e.g., oil) may be directed through the motor and / or the compressor (e.g., the one or more bearing assemblies) to facilitate rotation of the rotor shaft of the motor, and thus, rotation of the compressing member of the compressor (e.g., the impeller). During operation of the compressor (e.g., as the compressor operates to pressurize working fluid and direct working fluid through the vapor compression circuit), lubricant may inadvertently flow from the bearing assemblies and may flow toward certain areas within the compressor (e.g., impeller cavity, working fluid flow path), which may be undesirable. For example, lubricant within the impeller cavity may be entrained and / or mixed within the working fluid flow and may be discharged by the compressor toward downstream components of the vapor compression system (e.g., heat exchangers). Unfortunately, introduction of lubricant into the heat exchangers may limit an operational efficiency of the heat exchanger and / or cause wear and degradation to components of the heat exchanger.

[0023] Certain traditional compression systems (e.g., a motor and a compressor) may employ one or more dedicated components (e.g., separate component) to block flow of lubricant toward and / or into the impeller cavity and divert flow of the lubricant away from a working fluid flow path within the compressor. Such component(s) may be mounted on the rotating shaft of the motorbetween the impeller of the compressor and a bearing assembly positioned nearest the impeller of the compressor. As such, traditional components that are implemented to block and / or divert lubricant flow within the compressor may occupy axial space on the rotating shaft, which increases a distance (e.g., axial distance) between the bearing assembly and the impeller. Unfortunately, increased distances between the impeller and the bearing assembly may compromise rotodynamic stability. Further, such traditional components may not adequately direct a desired amount of lubricant away from the impeller cavity, and thus, lubricant may nevertheless flow into the impeller cavity (e.g., working fluid flow path) and ultimately be mixed with the working fluid directed to downstream components of the vapor compression system, which may be undesirable.

[0024] Accordingly, embodiments of the present disclosure are directed toward a lubricant diversion system (e.g., oil diversion system, integrated lubricant diversion system) that is configured to direct lubricant away from an impeller of a compressor, and thus, away from an impeller cavity and working fluid flow path of the compressor. That is, embodiments of the present disclosure are directed toward a lubricant diversion system that is configured to decrease, reduce, and / or block flow of lubricant into a compression side of a compression system (e.g., impeller side of a system having a compressor and a motor configured to operate to drive rotation of the compressor). For example, present embodiments are directed toward a lubricant diversion system that includes a balance piston (e.g., oil slinger, integrated balance piston, lubricant diverter) coupled to an impeller of a compressor. A pressure seal (e.g., high pressure seal, high pressure gas seal, labyrinth seal) may be mounted on the balance piston and may be configured to limit (e.g., block) an amount of lubricant from traveling from a motor side of the compression system to the compression side (e.g., impeller side, working fluid flow path) of the compressor system, thereby reducing an amount of mixing of the lubricant and the working fluid directed through the compression side of the compressor system.

[0025] Additionally, the balance piston may include an extension (e.g., flange, diverter) that extends beyond (e.g., outwardly from) the pressure seal in a direction toward the motor side of the compression system. During operation of the compressor, the balance piston may rotate along with the rotor shaft of the motor and may be configured to divert lubricant away from the pressure seal, thereby reducing an amount of lubricant introduced into the impeller cavity and the working fluid flow path. In this way, a reduced amount of lubricant may be mixed with the working fluiddirected through the vapor compression system by the compressor, thereby the increasing efficiency of the vapor compression system. Further, by employing the lubricant diversion systems discussed herein, fewer separate, ancillary components (e.g., dedicated components) may be implemented to divert lubricant away from the compression side of the compressor system. In this way, a distance (e g., an axial) between the impeller and a support (e.g., a bearing) of the rotor shaft coupled to the impeller may be reduced, thereby increasing a resonance frequency of the compressor system and / or increasing rotodynamic stability of the compressor system.

[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 air handler 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, an expansion valve(s) or device(s) 36, and a liquid chiller or an evaporator 38. 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 (e.g., water vapor), R-718, hydrofluorocarbon (HFC) based refrigerants, for example, R-410A, R-407, R-134a,hydrofluoro olefin (HFO), “natural” refrigerants like ammonia (NH3), R-717, carbon dioxide (CO2), R-744, or hydrocarbon based refrigerants, 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 compresses 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.

[0030] The liquid working fluid delivered to the evaporator 38 may 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 may undergo a phase change from the liquid working fluid to a working fluid vapor. 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 cooling 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 reducethe temperature of the cooling 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 by a suction line 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). 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 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 when entering the intermediate vessel 70 (e.g., due to a rapid increase in volume experienced when entering the intermediate 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 because of the expansion in 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 to the evaporator 38.

[0033] It should be appreciated that any of the features described herein may be incorporated within the vapor compression system 14 or any other suitable HVAC&R systems. 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 the HVAC&R system 10. Further, the present techniques may be incorporated with HVAC&R systems that utilize any suitable working fluid.

[0034] In accordance with the present techniques, motors having rotating components, such as the motor 50 for the compressor 32, may utilize lubricant diversion systems to enable operation of the motor 50 and the compressor 32 at various speeds while limiting an amount of fluid migration (e.g., lubricant migration) between a motor cavity of the motor 50 and a compression cavity (e.g., impeller side, impeller space, working fluid flow path, compression chamber) of the compressor 32 during an operative mode of the compressor 32. For example, embodiments of the lubricant diversion system discussed herein are configured to block flow of fluid (e.g., lubricant) from the motor cavity of the motor 50 to the compression cavity of the compressor 32 and to divert and / or re-direct escaped lubricant away from the compression cavity of the compressor 32.

[0035] To facilitate the following discussion, FIG. 5 is a cross-sectional view of a compressor system 100 (e g., compression section) 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 the present 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 compressor 32 and / or the motor 50. In certain 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. 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 (e.g., shaft) of the motor 50 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 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 fastener 110 (e.g., bolt, rod), thereby enabling rotation of the impeller 108 within an impeller cavity 109 (e.g., compression cavity, impeller space) As the motor 50 isoperated, the rotor shaft 106 may be driven into rotation to rotate the impeller 108 of the compressor 32, thereby enabling the compressor 32 to compress a working fluid within the impeller cavity 109 to a desired pressure before directing the working fluid out of a volute portion 112 of the compressor 32 and along a working fluid circuit toward downstream components of the vapor compression system 14 (e.g., a heat exchanger, such as a condenser and / or an evaporator).

[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 of the compressor system 100. In certain embodiments, the rotor shaft 106 may be supported by one or more bearings assemblies (e.g., lubricant bearing assemblies, bearings), and the bearing assemblies may be 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. For example, a first bearing 114 (e.g., first set of bearings, first bearing assembly) may be disposed proximate a first end of the rotor shaft 106 to which the impeller 108 is secured via the fastener 110. That is, the first bearing 114 may be axially spaced (e.g., along the longitudinal axis 200) from the impeller 108, such as by a distance less than a threshold distance away from the impeller 108. Reduced axial spacing between the bearing 114 and the impeller 108 may improve rotodynamic stability in the compressor system 100. A second bearing 115 (e.g., second set of bearings) may be disposed proximate a second end of the rotor shaft 106, opposite the first end (e.g., proximate an end of the rotor shaft 106 that is not coupled to the impeller 108). Each bearing 114, 115 may be fluidly coupled to a lubricant source 116 via one or more conduits 118 (e.g., lubricant conduit, lubricant circuit, lubricant flow path). Each conduit 118 (e.g., flow path) may be configured to direct lubricant toward a respective bearing assembly 114, 115, thereby facilitating rotation of the rotor shaft 106 about the longitudinal axis 200 (e.g., within the bearing assemblies 114, 115, relative to the radial axis 202). The bearing assemblies 114, 115 may include any suitable bearings circumferentially disposed around the rotor shaft 106 (e.g., in the circumferential direction 204), such as journal bearings, ball bearings, sleeve bearings, roller bearings, and so forth.

[0037] In certain embodiments, the compressor system 100 of the vapor compression system 14 may include a lubricant diversion system 120 (e.g., integrated balance piston and lubricantslinger, integrated seal and lubricant slinger, integrated balance piston and lubricant diverter) configured to block and / or limit an amount of fluid migration (e.g., lubricant migration) toward the impeller cavity 109 (e.g., block and / or limit an amount of fluid migration from the motor cavity of the motor 50 to the compression cavity of the compressor 32, block and / or limit an amount of fluid migration from the motor housing portion 104 to the compressor housing portion 102) and / or to redirect lubricant away from the impeller cavity 109 (e.g., redirect lubricant away from the compressor housing portion 102, redirect lubricant away from the impeller 108). For example, the lubricant diversion system 120 may include and / or may be integrated with a balance piston 122 configured to reduce a thrust load on the impeller 108. The balance piston 122 may be coupled (e.g., integrally coupled, integrally formed with, mounted, secured, mechanically coupled) to the impeller 108 and may rotate with the impeller 108 during operation of the compressor system 100. In certain embodiments, as the impeller 108 rotates, thrust forces may be generated in a direction along the longitudinal axis 200 of the compressor system 100. Thus, during operation, the balance piston 122 may be configured to engage with (e.g., abut) other components of the compressor system 100 (e.g., the housing 101) to limit athrust force (e.g., thrust load) generated on the impeller 108 during operation (e.g., rotation) of the compressor system 100. In the illustrated embodiment, the balance piston 122 is integrally formed with the impeller 108. However, in other embodiments (e.g., FIG. 7) the balance piston 122 may be coupled (e.g., mounted, secured) to the impeller 108 via one or more fasteners, as described in greater detail below.

[0038] In certain embodiments, the balance piston 122 may include a body (e.g., annular body) and may have a wall portion 124 (e.g., protrusion, extension, axial extension) and a cavity 126 (e.g., annular cavity, chamber, pocket, recess) at least partially defined by the wall portion 124. In certain embodiments, a portion of the impeller 108 (e.g., a hub of the impeller 108) may further define the cavity 126. For example, in the illustrated embodiment, the balance piston 122 is integrally formed with the impeller 108, and a portion 111 (e.g., curved portion, arcuate portion, hub) of the impeller 108 that extends at least partially along the radial axis 202 (e.g., extends at a non-zero angle relative to the longitudinal axis 200) may further define the cavity 126. The wall portion 124 may extend in a direction (e.g., linear direction) along the longitudinal axis 200 of the rotor shaft 106 and may be configured to redirect lubricant that inadvertently escapes from the bearings 114, 115 to flow away from the compression cavity of the compressor system 100 (e.g., away from the compressor housing section 102, away from the impeller cavity 109). In certainembodiments, at least a portion of the wall portion 124 (e.g., a distal end of the wall portion, a free end of the wall portion) may extend at an angle (e g., a non-zero angle) relative to the longitudinal axis 200. For example, in certain embodiments, the wall portion 124 may extend at an angle (e.g., non-zero angle, radially inward angle) toward the rotor shaft 106, while in other embodiments, the wall portion 124 may extend at an angle (e.g., non-zero angle, radially outward angle) away from the rotor shaft 106. By orienting the wall portion 124 at an angle relative to the longitudinal axis 200, the balance piston 122 may more effectively remove lubricant that has escaped from the bearings 114, 115. For example, by orienting the wall portion 124, or at least the distal end of the wall portion 124 at a radially outward angle relative to the longitudinal axis 200, lubricant directed out of the cavity 126 may flow along the wall portion 124. Notably, because the free end of the wall portion 124 is oriented at a radially outward angle relative to the longitudinal axis 200, the free end of the wall portion 124 may extend beyond at least a portion of a seal 130 in a direction along the radial axis 202 away from the rotor shaft 106, thereby blocking and / or limiting an amount of lubricant from being introduced to the seal 130.

[0039] The cavity 126 may be fluidly coupled to a passage 128 and may be configured to receive (e.g., capture) lubricant that escapes from the bearings 114, 115 (e.g., lubricant within the housing 101, lubricant within the motor housing portion 104). The impeller 108 and / or the balance piston 122 may direct the lubricant captured within the cavity 126 to flow toward the passage 128. For example, as the balance piston 122 rotates (e.g., via rotation of the impeller 108), lubricant within the cavity 126 may impinge upon the wall portion 124 and / or the portion 111 of the impeller 108 before being directed out of the cavity 126 and into (e.g., through) the passage 128. That is, as the impeller 108 rotates, centrifugal forces induced along the radial axis 202 and away from the rotor shaft 106 may be generated that cause lubricant within the cavity 126 to flow against and / or along the portion 111 of the impeller 108 and the wall portion 124 (e.g., at least partially along the radial axis 202) away from the rotor shaft 106. As the lubricant flows away from the rotor shaft 106, the lubricant may impinge upon the wall portion 124 of the balance piston 122 and / or the portion 111 of the impeller 108, thereby enabling the lubricant to be directed (e.g., diverted) into the passage 128. The passage 128 may be configured to deliver the lubricant out of the housing 101 (e.g., to a periphery of the housing 101, away from the impeller cavity 109) before returning the lubricant to the lubricant source 116.

[0040] In certain embodiments, the seal 130 (e.g., high-pressure gas seal, pressure seal, labyrinth seal) may be disposed (e.g., mounted) on the balance piston 122 and may be configured to engage with (e.g., abut) the wall portion 124 of the balance piston 122 to limit (e.g., block) fluid migration (e.g., lubricant migration) from the motor housing section 104 to the compressor housing section 102 (e.g., block fluid migration into the impeller cavity 109) and / or fluid migration (e.g., working fluid migration) from the compressor housing portion 102 to the motor housing portion 104. For example, the seal 130 may be a labyrinth seal having a sealing extension and a T-shaped cross section with a toothed surface configured to block fluid (e.g., lubricant) flowing within the passage 128 from flowing across the seal 130 toward the impeller cavity 109. Additionally, or alternatively, the seal 130 may be configured to block a flow (e.g., leakage) of working fluid from the working fluid flow path within the compressor housing section 102 into the motor housing portion 104.

[0041] In certain embodiments, the wall portion 124 of the balance piston 122 may be configured to extend beyond the seal 130 (e.g., extend beyond a lateral boundary of the seal 130, extend beyond a lateral perimeter of the seal 130, extend further along the longitudinal axis 200 toward the motor housing portion 104, relative to the seal 130) in a direction along the longitudinal axis 200 (e.g., axial axis) of the compressor system 100 to facilitate diversion of lubricant away from the impeller cavity 109. For example, the wall portion 124 may extend for a length along the longitudinal axis 200, and the length of the wall portion 124 may be greater than a length of the seal 130 along the longitudinal axis 200 (e.g., greater than a length of a sealing portion of the seal 130 that engages with the wall portion 124) such that the wall portion 124 extends beyond a lateral boundary of the seal 130 along the longitudinal axis 200. As the centrifugal forces (e.g., generated via rotation of the impeller 108 and / or the balance piston 122) cause lubricant to be directed away from the rotor shaft 106 (e.g., in a direction along the radial axis 202), the portion 111 of the impeller 108 and / or the wall portion 124 may further divert the lubricant away from the seal 130, thereby limiting an amount of lubricant from being introduced to the seal 130, as described in greater detail below. By decreasing an amount of lubricant introduced to the seal 130, a decreased amount of lubricant may be directed into the impeller cavity 109, thereby mitigating mixing of the lubricant with working fluid in the impeller cavity 109, which enables more efficient operation of the compressor system 100 and the vapor compression system 14.

[0042] As noted above, incorporation of the wall portion 124 and the balance piston 122 (e.g., the lubricant diversion system 120) with the impeller 108, in accordance with the present techniques, enables positioning of the impeller 108 in closer proximity (e.g., along the longitudinal axis 200) to the bearing 114 (e.g., less than a threshold distance). In this way, a resonance frequency of the rotor shaft 106 may be increased and / or rotodynamic stability of the compressor system 100 may be improved. To this end, in certain embodiments, the bearing 114 may at least partially extend along the longitudinal axis 200 into the cavity 126 of the balance piston 122 (e.g., positioned at least partially within the cavity 126). By positioning the bearing 114 at least partially within the cavity 126, the rotor shaft 106, the bearing 114, and the impeller 108 (e.g., the compressor system 100) may be assembled with a reduced axial dimension (e.g., along the longitudinal axis 200), which enables improved rotodynamic stability while also reducing costs associated with the manufacture and assembly of such compressor systems. For example, by positioning the bearing 114 at least partially within the cavity 126, shorter rotor shafts 106 may be implemented in the compressor system 100 relative to traditional compressor systems.

[0043] In certain embodiments, the compressor system 100 may include one or more sensors 140 configured to detect various operating parameters and / or operating conditions of the compressor system 100. The one or more sensors 140 may be disposed throughout the compressor 32 and / or the motor 50 and may be configured to detect data indicative of a temperature, a pressure, a flow rate, or a composition of fluid (e.g., working fluid, lubricant) directed through the compressor 32 and / or the motor 50. Such data may also be utilized to determine an amount of lubricant within the compressor housing portion 102 and / or the motor housing portion 104. For example, data detected by one of the sensors 140 may indicate that a pressure and / or a temperature of the working fluid is outside a threshold range, which may be indicative of a threshold amount (e.g., undesirable amount) of lubricant within the working fluid. The one or more sensors 140 may communicate detected data to a controller 150 (e.g., control panel 40, control system, automation controller), thereby enabling the controller 150 to control operation of the compressor system 100. For example, the controller 150 may be configured to control an amount of lubricant directed from the lubricant source 116 to the bearings 114 and / or to control a speed of the motor 50 (e.g., and thus a rotation rate of the impeller 108 and the balance piston 122) based on the data from the one or more sensors 140, as described in greater detail below. That is, in certain embodiments, certain components of the compressor system 100 may be communicatively coupled to the controller 150,thereby enabling the controller 150 to control operation of the compressor system 100 and / or the lubricant diversion system 120 (e.g., by controlling a rotation rate of the balance piston 122), as described in greater detail below.

[0044] In certain embodiments, the controller 150 may include processing circuitry 152 (e.g., one or more microprocessors) and a memory 154. For example, the controller 150 may include non-transitory code or instructions stored in a machine-readable medium (e.g., the memory 154) that is used by the processing circuitry 152 to implement the techniques disclosed herein. The memory 154 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 152, control operation of the compressor system 100 and / or the lubricant diversion system 120. The controller 150 may monitor and control operation of the lubricant diversion system 120, for example, by controlling a rotation rate of the rotor shaft 106, and thus a rotation rate of the impeller 108 and / or the balance piston 122.

[0045] In certain embodiments, the controller 150 may control operation of the compressor system 100 based on feedback received from the one or more sensors 140. For example, upon receiving sensor data indicative of a threshold amount of lubricant within the impeller cavity 109, the controller 150 may send a signal to the lubricant source 116 to reduce an amount of lubricant directed toward the bearings 114. Additionally, or alternatively, the controller 150 may send a signal to the motor 50 to increase a speed (e.g., a rotation rate) of the rotor shaft 106. By increasing the rotation rate of the rotor shaft 106, the rotation rate of the impeller 108 and the balance piston 122 may increase, thereby enabling the lubricant diversion system 120 to direct lubricant along the passage 128 and away from the seal 130 in a more efficient manner relative to compressors operating at lower speeds. For example, increasing the rotation rate of the impeller 108 and the balance piston 122 may cause the aforementioned centrifugal forces acting on the lubricant within the cavity 126 to increase, thereby decreasing a tendency for the lubricant to flow in a direction toward the impeller cavity 109. In this way, lubricant may be blocked and / or limited from traveling into the impeller cavity 109, thereby reducing an amount of mixing between the working fluid and the lubricant and increasing the efficiency of a vapor compression system employing the compressor system 100. It should be appreciated that in certain embodiments, the controller 150may control operation of the compressor system 100 based on a manual input provided via an operator associated with the compressor 32.

[0046] FIG. 6 is a cross-sectional side view of a portion of an embodiment of the compressor system 100, taken within dashed line 5-5 of FIG. 5, illustrating an embodiment of the lubricant diversion system 120. As shown in FIG. 6, the lubricant diversion system 120 includes the balance piston 122 having the wall portion 124 that at least partially defines the cavity 126. In the illustrated embodiment, the balance piston 122 is integrally formed with the impeller 108 (e.g., as a single piece component), and thus, the portion 111 of the impeller 108 further defines the cavity 126. Additionally, a portion 160 of the housing 101 (e.g., a portion of the motor housing portion 104) may further define the cavity 126. As noted above, the cavity 126 may be configured to receive lubricant that has escaped from the bearing 114, and the portion 111 of the impeller 108, the balance piston 122, and / or the wall portion 124 may direct the lubricant toward the passage 128, thereby enabling the passage 128 to direct the lubricant out of the compressor system 100 (e.g., return the lubricant to the lubricant source 116). For example, centrifugal forces generated during rotation of the balance piston 122 and the impeller 108 may cause lubricant within the cavity 126 to flow along a lubricant flow path 162 toward the passage 128.

[0047] Due to the geometry of the portion 111 of the impeller 108 that at least partially defines the cavity 126, the cavity 126 may have a slanted profile (e.g., relative to the longitudinal axis 200) that facilitates diversion of the lubricant away from the impeller cavity 109 (e.g., at least partially along the radial axis 202) and / or diversion of the lubricant away from the seal 130. For example, as lubricant escapes from the bearing 114, the lubricant may travel in a first direction 170 (e.g., a direction along the longitudinal axis 200) toward the impeller cavity 109. However, rotation of the balance piston 122 may force the lubricant to travel along the lubricant flow path 162 in a second direction 172 that at least partially extends along the radial axis 202 away from the rotor shaft 106. As the lubricant travels along the lubricant flow path 162 in the second direction 172, the lubricant may impinge upon the portion 111 of the impeller 108, thereby causing the lubricant to flow in a third direction 174 that extends at an angle (e.g., non-zero angle, radially outward angle) relative to the radial axis 202 at least partially in a direction opposite the direction 170. That is, the balance piston 122 (e.g., the portion 111 of the impeller 108 and the wall portion 124) may be configured to modify a flow direction of the lubricant within the cavity 126 to facilitatediversion of the lubricant out of the compressor system 100. Additionally, due to the slanted profile of the cavity 126, tangential forces may be generated that further aid in diverting the lubricant from the cavity 126 and into the passage 128. For example, because the portion 111 of the impeller 108, the wall portion 124, and the portion 160 of the housing 101 change the flow direction of the lubricant within the cavity 126, as the lubricant flow changes direction, tangential forces acting in a direction that is opposite the direction 170 may be imparted to the lubricant flow. In this way, the tangential forces may further divert the lubricant toward the passage 128, thereby enabling the lubricant to bypass (e.g., be diverted from) the seal 130. That is, an increased amount of lubricant within the cavity 126 may be directed through the passage 128 and away from the impeller cavity 109 relative to traditional compressor systems. Furthermore, the centrifugal forces generated via rotation of the impeller 108 and the balance piston 122 may cause a velocity of the lubricant flowing within the passage 128 to increase. As the velocity of the lubricant directed through the passage 128 increases, a tendency for the lubricant to change direction and / or flow toward the seal 130 may decrease (e.g., due to inertia), thereby causing a reduced amount of lubricant to be introduced to the seal 130. In turn, a reduced amount of lubricant may be directed into the impeller cavity 109, thereby mitigating introduction of the lubricant into the working fluid directed through the compressor system 100, which enables an increase in efficiency of the vapor compression system 14.

[0048] As noted above, in certain embodiments, at least a portion of the bearing 1 14 may extend in a direction (e.g., horizontal direction) along the longitudinal axis 200, such that the bearing 114 is at least partially positioned within (e.g., radially within, relative to the radial axis 202, longitudinally within, relative to the longitudinal axis 200) the cavity 126. By positioning at least a portion of the bearing 114 within the cavity 126, a first end 180 of the bearing 114 (e.g., end of the bearing 114 proximate the impeller 108) may be less than a threshold distance from the impeller 108. More compact positioning (e.g., axial positioning) of the bearing 114 and the impeller 108 relative to one another (e.g., along the rotor shaft 106) may reduce an amount of axial space 182 between the impeller 108 and the bearing 114, thereby increasing the rotodynamic stability of the compressor system 100 while reducing costs associated with the manufacture and assembly of such compressor systems.

[0049] As noted above, in certain embodiments, at least a portion of the wall portion 124 may extend beyond a lateral boundary 184 (e.g., lateral perimeter, axial edge) of the seal 130 (e.g., of a sealing portion of the seal 130 that engages with the wall portion 124) in a direction along the longitudinal axis 200. By extending the wall portion 124 beyond the lateral boundary 184 (e.g., along the longitudinal axis 200, toward the motor 50) of the seal 130, a reduced amount of lubricant may be introduced to the seal 130. For example, as the impeller 108 with the balance piston 122 rotates, lubricant may flow along the lubricant flow path 162 before reaching a distal end 186 of the wall portion 124 (e.g., free end of the wall portion 124). Upon reaching the distal end 186 of the wall portion 124, the lubricant may be slung (e.g., thrusted, forced, driven) in a direction (e.g., radially outward direction) along the radial axis 202 away from the rotor shaft 106 and into the passage 128. Notably, the centrifugal forces generated during rotation of the impeller 108 and the balance piston 122 and / or the tangential forces generated as the lubricant impinges upon portions of the impeller 108 and / or the balance piston 122 (e.g., portion 111 of the impeller 108, portion 160 of the housing 101, wall portion 124) may cause the lubricant flow to be directed out of the cavity 126 with a velocity that enables the lubricant flow to bypass the seal 130. In this way, a likelihood and / or tendency of the lubricant to flow in the direction 170 toward the seal 130 and the impeller cavity 109 may be reduced. Moreover, an additional clearance provided by extending the wall portion 124 beyond the lateral boundary 184 of the seal 130 may further divert the lubricant away from the seal 130 and thereby reduce an amount of lubricant that is introduced to the seal 130. Additionally, as noted above, in certain embodiments, the distal end 186 of the wall portion 124 may extend at an angle (e.g., non-zero angle relative to the longitudinal axis 200, radially outward angle) to facilitate diversion of the lubricant away from the seal 130. For example, in embodiments in which the distal end 186 of the wall portion 124 extends at a radially outward angle relative to the longitudinal axis 200, the distal end 186 of the wall portion 124 may at least partially align with a portion of the seal 130 along the longitudinal axis 200. In this way, the distal end 186 of the wall portion 124 may serve to shield and / or block lubricant from reaching the seal 130.

[0050] FIG. 7 is a cross-sectional side view of a portion of an embodiment of the compressor system 100, illustrating an embodiment of a lubricant diversion system 300. The lubricant diversion system 300 may include similar features to the lubricant diversion system 120 described above. For example, the lubricant diversion system 300 may include a balance piston 302, apassage 304, and a seal 306 (e.g., high-pressure gas seal) disposed within the motor housing portion 104 of the compressor system 100. In the illustrated embodiment, the balance piston 302 includes a first portion 308 (e.g., rotor shaft portion, first axial portion, linear portion, mounting portion) configured to at least partially circumscribe and / or radially engage with the rotor shaft 106. The first portion 308 may extend in a direction (e.g., linear direction, longitudinal direction) along the longitudinal axis 200 and may be configured to engage with (e.g., abut, contact) the rotor shaft 106. The balance piston 302 may include a second portion 310 (e.g., impeller portion, impeller hub portion, radial portion) extending from the first portion 308 in a direction (e.g., radial direction) along the radial axis 202, and a third portion 312 (e.g., wall portion, extension, second axial portion, linear portion) extending from the second portion 310 in a direction (e.g., linear direction, longitudinal direction) along the longitudinal axis 200. In certain embodiments, the third portion 312 may extend at an angle (e.g., non-zero angle, radially inward angle) toward the rotor shaft 106, while in other embodiments, the third portion 312 may extend at an angle (e.g., nonzero angle, radially outward angle) away from the rotor shaft 106. By orienting the third portion 312 at an angle relative to the longitudinal axis 200, the balance piston 302 may more effectively divert lubricant that has escaped from the bearings 114, 115 to flow away from the impeller cavity 109, as described above. It should be appreciated that the balance piston 302 may be formed from a single piece of material, or alternatively, each of the first, second, and third portions 308, 310, 312 may be coupled to one another via any suitable technique (e.g., welding, brazing).

[0051] As shown in FIG. 7, the first portion 308, the second portion 310, and the third portion 312 may collectively define a cavity 314 (e.g. C-shaped cavity, chamber, recess, pocket) configured to capture lubricant that may escape and / or flow from the bearing 114. Similar to the balance piston 122 described above, rotation of the impeller 108 and the balance piston 302 may cause lubricant within the cavity 314 to flow along a lubricant flow path 316 toward the passage 304, thereby enabling the lubricant to bypass the seal 306. As noted above, in certain embodiments, the balance piston 302 may be mechanically coupled (e.g., attached, secured) to the impeller 108. For example, in the illustrated embodiment, a fastener 318 extends through the second portion 310 of the balance piston 302 and into a body (e.g., a hub) of the impeller 108 (e.g., in a direction along the longitudinal axis 200) to fasten the balance piston 302 to the impeller 108. Thus, as the motor 50 operates to drive the compressor 32 (e.g., as the motor 50 operates to rotate the impeller 108), the balance piston 302 may also rotate, thereby enabling lubricant to be divertedaway from the impeller cavity 109 and / or enabling lubricant to bypass the seal 306, in the manner described above.

[0052] Similar to the embodiment described above, the third portion 312 of the balance piston 302 may be configured to extend beyond the seal 306 (e.g., extend beyond a lateral boundary 320 of the seal 306) in a direction along the longitudinal axis 200 to facilitate diversion of the lubricant away from the impeller cavity 109. For example, the third portion 312 may extend for a length along the longitudinal axis 200, and the length of the third portion 312 may be greater than a length of the seal 306 along the longitudinal axis 200 such that the third portion 312 extends beyond the lateral boundary 320 of the seal 306 in a direction 322 toward the bearing 114 along the longitudinal axis 200. In this way, additional clearance may be provided between the passage 304 and the seal 306, thereby reducing an amount of lubricant introduced to the seal 306.

[0053] Further, as noted above, the present techniques enable the bearing 114, the rotor shaft 106, and the impeller 108 to be assembled in a more compact (e.g., axially compact) arrangement. That is, the bearing 114 and the impeller 108 may be positioned closer to one another along the longitudinal axis 200. In this way, the present techniques enable increased rotodynamic stability of the compressor system 100. To this end, the bearing 114 may at least partially extend along the longitudinal axis 200 into the cavity 314 of the balance piston 302 (e.g., to be positioned at least partially within the cavity 314). By positioning the bearing 114 at least partially within the cavity 314, an axial distance between the impeller 108 and the bearing 114 may be reduced, thereby improving the rotodynamic stability of the compressor system 100. That is, a distance 324 between the impeller 108 and the first end 180 of the bearing 114 along the longitudinal axis 200 may be reduced relative to existing systems that incorporate separate and / or dedicated components to reduce flow of lubricant from a bearing to an impeller.

[0054] During operation of the compressor system 100, the lubricant diversion system 300 may be configured to direct lubricant collected within the cavity 314 toward a periphery (e.g., radial periphery) of the compressor system 100 (e.g., away from the impeller cavity 109, away from the seal 306). For example, similar to the operation of the lubricant diversion system 120, the balance piston 302 of the lubricant diversion system 300 may be configured to rotate along with the impeller 108 to divert (e.g., sling, force) lubricant out of the cavity 314. Rotation of thebalance piston 302 may cause centrifugal forces to be generated that act on the lubricant within the cavity 314, thereby causing the lubricant within the cavity 314 to flow in a direction (e.g., radially outward direction) at least partially along the radial axis 202 away from the rotor shaft 106. As the lubricant travels along the radial axis 202 away from the rotor shaft 106, the lubricant may impinge upon the balance piston 302 (e.g., impinge upon the second portion 310 and / or third portion 312) before being directed out of the cavity 314 and into the passage 304. Further, the centrifugal forces generated during rotation of the balance piston 302 may cause a velocity of the lubricant flow (e.g., from the cavity 314 to the passage 304) to increase. Because the centrifugal forces are oriented in a direction along the radial axis 202 away from the rotor shaft 106, as the lubricant flow reaches a distal end (e.g., free end) of the third portion 312, the centrifugal forces may act on the lubricant flow, thereby forcing the lubricant flow out of the cavity 314 and into the passage 304. Notably, because the third portion 314 extends axially beyond the lateral boundary 320 of the seal 306 (e.g., toward the motor 50), a decreased amount of lubricant may flow toward the seal 306. Instead, the lubricant may bypass the seal 306 by virtue of the centrifugal forces forcing the lubricant away from the rotor shaft 106.

[0055] As set forth above, the present disclosure may provide one or more technical effects useful in operating compressor systems that are configured to circulate lubricant to facilitate operation of the compressor system. Embodiments of the present disclosure may include a lubricant diversion system configured to divert escaped lubricant away from an impeller cavity in which an impeller of the compressor system is positioned. The lubricant diversion system may include a balance piston coupled to the impeller that includes structural portions that facilitate collection (e.g., capture) and diversion (e.g., discharge) of lubricant away from the impeller cavity. For example, the balance piston may include a wall portion that at least partially defines a cavity configured to capture the lubricant that may escape from a bearing of the compressor system. The wall portion may extend axially beyond a lateral boundary of a seal, such that lubricant captured by the cavity may be directed into a passage, thereby enabling the lubricant to bypass the seal. In this way, a decreased amount of lubricant may be introduced into the impeller cavity. Additionally, by employing the lubricant diversion systems discussed herein, a bearing configured to support a rotor shaft of a motor operatively coupled to the compressor may be positioned (e.g., assembled) in closer axial proximity to the impeller relative to traditional compressor systems. That is, employing the lubricant diversion systems discussed herein may decrease an axial distancebetween the bearing and the impeller, thereby improving the rotodynamic stability of the compressor system, while reducing costs associated with the manufacture and assembly of such compressor systems. Further still, by reducing an amount of lubricant introduced into the impeller cavity, a reduced amount of lubricant may be introduced to a working fluid (e.g., refrigerant) directed through the compressor, thereby avoiding introduction of lubricant to components downstream of the compressor system (e.g., heat exchanger, such as an evaporator and / or condenser), which may result in improved heat exchange efficiency of such components.

[0056] 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 invention.

[0057] Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode, or those unrelated to enablement. 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.

[0058] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible or purely theoretical. Further, if any claims appended to the end of this specification contain one or more elements designated as “means for [perform]ing [a function]...” or “step for [perform]ing [a function]...”, it is intended that suchelements are to be interpreted under 35 U.S.C. 112(f). However, for any claims containing elements designated in any other manner, it is intended that such elements are not to be interpreted under 35 U.S.C. 112(f).

Claims

CLAIMS:

1. A compressor system, comprising: a housing comprising an impeller disposed therein, wherein the impeller is configured to rotate within an impeller cavity of the housing to compress a working fluid; 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; a bearing disposed circumferentially about the rotor shaft, wherein the bearing is configured to receive a lubricant from a lubricant source to facilitate rotation of the rotor shaft; and a lubricant diversion system configured to divert the lubricant away from the impeller cavity, the lubricant diversion system comprising: a seal configured to block flow of the lubricant into the impeller cavity; and a balance piston coupled to the impeller, wherein the balance piston is configured to divert the lubricant away from the seal.

2. The compressor system of claim 1, wherein the balance piston comprises a wall portion configured to at least partially define a cavity configured to capture the lubricant escaped from the bearing.

3. The compressor system of claim 2, wherein the lubricant diversion system comprises a passage defined within the housing, the cavity is fluidly coupled to the passage, and the balance piston is configured to direct the lubricant toward the passage during rotation of the balance piston.

4. The compressor system of claim 2, wherein the balance piston is configured to direct the lubricant to flow through the cavity and radially away from the rotor shaft to bypass the seal.

5. The compressor system of claim 2, wherein the wall portion extends axially beyond a lateral boundary of the seal in an axial direction toward the bearing.

6. The compressor system of claim 2, wherein the seal is configured to engage with a surface of the wall portion to block the flow of the lubricant into the impeller cavity.

7. The compressor system of claim 2, wherein the bearing extends at least partially within the cavity in an axial direction.

8. The compressor system of claim 1, wherein the balance piston is integrally formed with the impeller.

9. The compressor system of claim 1, wherein the balance piston is coupled to the impeller via one or more fasteners.

10. The compressor system of claim 1, wherein the seal is a labyrinth seal.

11. The compressor system of claim 1, comprising: one or more sensors configured to detect data indicative of an amount of the lubricant within the housing; and a controller configured to control operation of the compressor system based on the amount of the lubricant within the housing.

12. The compressor system of claim 11, wherein the controller is configured to increase a speed of the motor based on the amount of the lubricant exceeding a threshold amount.

13. A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising: a compressor comprising an impeller configured to rotate within a compression cavity to compress a working fluid and to 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 lubricant diversion system configured to block flow of a lubricant into the compression cavity, wherein the lubricant diversion system comprises:a balance piston comprising a wall portion that at least partially defines a chamber configured to capture the lubricant; and a seal comprising a sealing portion configured to engage with the wall portion, wherein the balance piston is configured to rotate with the impeller and to direct the lubricant within the chamber to flow away from the seal.

14. The HVAC&R system of claim 13, comprising a bearing configured to receive the lubricant from a lubricant source, wherein the bearing extends at least partially into the chamber in an axial direction.

15. The HVAC&R system of claim 14, wherein the sealing portion of the seal extends a first length in the axial direction, the wall portion of the balance piston extends a second length in the axial direction, and the first length is less than the second length, such that the wall portion extends toward the motor and beyond an edge of the sealing portion in the axial direction.

16. The HVAC&R system of claim 13, wherein a portion of the impeller at least partially defines the chamber, and wherein the chamber comprises a slanted profile configured to divert flow of the lubricant away from the seal.

17. A lubricant diversion system for a compressor system, comprising: a balance piston coupled to an impeller of the compressor system, wherein the balance piston comprises: a wall portion configured to extend in an axial direction of the compressor system; and a cavity at least partially defined by the wall portion, wherein the cavity is configured to receive lubricant from a bearing of the compressor system; and a seal configured to abut the wall portion and block flow of the lubricant toward the impeller, wherein the balance piston is configured to rotate with the impeller during operation of the compressor system and to divert the lubricant away from the seal.

18. The lubricant diversion system of claim 17, wherein the balance piston is integrally formed with the impeller as a single piece.

19. The lubricant diversion system of claim 18, wherein the cavity is at least partially defined by a hub of the impeller.

20. The lubricant diversion system of claim 17, wherein the balance piston comprises an additional wall portion extending in a radial direction and configured to abut the impeller, and the balance piston is coupled to the impeller via one or more fasteners extending through the additional wall portion and into the impeller.

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