Porous gas bearing

Abstract

A porous gas bearing is disclosed. The porous gas bearing includes a housing having a fluid inlet and a bore. A porous surface layer is disposed within the housing and circumferentially surrounds the bore. The porous surface layer includes a plurality of segments arranged along a longitudinal direction of the bore. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a plurality of dampeners. The plurality of dampeners is disposed circumferentially around the bore. The plurality of dampeners is arranged between a first segment of the plurality of segments of the porous surface layer and a second segment of the plurality of segments of the porous surface layer.

Description

[0001] This application is a divisional application of application number 201910501896.4 entitled "Porous Gas Bearing". Technical Field

[0002] This disclosure generally relates to bearings for heating, ventilation, air conditioning and refrigeration (HVACR) systems. More specifically, this disclosure relates to porous gas bearings for compressors in HVACR systems. Background Technology

[0003] Heating, ventilation, air conditioning, and refrigeration (HVACR) systems typically include compressors. Compressors, such as but not limited to centrifugal compressors, screw compressors, and scroll compressors, utilize bearings to support a rotating shaft. Various types of bearings are considered, including fluid dynamic oil bearings that require lubrication systems and ball bearings. In some cases, oil-free operation is preferred. Such systems often use magnetic bearings. Magnetic bearings do not use lubricants, but they are expensive and require a control system.

[0004] HVACR systems can be used in buildings or in transportation applications (e.g., trucks, cars, buses, trains, etc.). Summary of the Invention

[0005] This specification generally relates to bearings used in heating, ventilation, air conditioning and refrigeration (HVACR) systems. More specifically, this specification relates to porous gas bearings used in compressors within HVACR systems.

[0006] In one embodiment, a porous gas bearing is disclosed. The porous gas bearing can be used, for example, to support a shaft, such as, but not limited to, the compressor shaft of a compressor in an HVACR system. In one embodiment, the compressor can be a centrifugal compressor. In one embodiment, the centrifugal compressor is an oil-free centrifugal compressor.

[0007] The porous gas bearing may include damping features. In one embodiment, the porous gas bearing may include multiple damping features. The damping features may, for example, reduce the radial displacement of the compressor shaft.

[0008] This application discloses a porous gas bearing. The porous gas bearing includes a housing having a fluid inlet and a hole. A porous surface layer is disposed within the housing and surrounds the hole circumferentially. The porous surface layer includes multiple segments arranged longitudinally along the hole. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes multiple dampers. The multiple dampers are arranged circumferentially around the hole. The multiple dampers are disposed between a first segment and a second segment of the multiple segments of the porous surface layer.

[0009] This application discloses a refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, an expander, and an evaporator fluidly connected. The compressor includes a shaft. The shaft is supported by a porous gas bearing. The porous gas bearing includes a housing having a fluid inlet and a hole. A porous surface layer is disposed within the housing and surrounds the hole circumferentially. The porous surface layer includes multiple sections arranged longitudinally along the hole. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes multiple dampers. The multiple dampers are arranged circumferentially around the hole. The multiple dampers are disposed between a first section and a second section of the multiple sections of the porous surface layer.

[0010] This application discloses a centrifugal compressor. The centrifugal compressor includes a rotating shaft and a porous gas bearing. The porous gas bearing includes a housing having a fluid inlet and a hole. A porous surface layer is disposed within the housing and surrounds the hole circumferentially. The porous surface layer includes multiple sections arranged longitudinally along the hole. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes multiple dampers. The multiple dampers are arranged circumferentially around the hole in the housing. The multiple dampers are disposed between a first section and a second section of the multiple sections of the porous surface layer.

[0011] This application discloses a porous gas bearing. The porous gas bearing includes a housing having a fluid inlet and a hole. A porous surface layer is disposed within the housing and surrounds the hole circumferentially. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a biasing member. The biasing member is disposed in a channel extending longitudinally and circumferentially around the hole. The biasing member is arranged radially outward from the porous surface layer.

[0012] This document discloses a refrigerant circuit. The refrigerant circuit includes a compressor, a condenser, an expander, and an evaporator, all fluidly connected. The compressor includes a shaft. The shaft is supported by a porous gas bearing. The porous gas bearing includes a housing having a fluid inlet and a hole. A porous surface layer is disposed within the housing and circumferentially surrounds the hole. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a biasing member. The biasing member is disposed in a channel extending longitudinally and circumferentially around the hole. The biasing member is arranged radially outward from the porous surface layer.

[0013] This application discloses a centrifugal compressor. The centrifugal compressor includes a rotating shaft and a porous gas bearing. The porous gas bearing includes a housing having a fluid inlet and a hole. A porous surface layer is disposed within the housing and surrounds the hole circumferentially. The porous surface layer is in fluid communication with the fluid inlet. A damping system includes a biasing member. The biasing member is disposed in a channel extending longitudinally and circumferentially around the hole. The biasing member is arranged radially outward from the porous surface layer. Attached Figure Description

[0014] Referring to the accompanying drawings, which form part of this disclosure, embodiments of the systems and methods described herein can be practiced.

[0015] Figure 1 This is a schematic diagram of a refrigeration circuit according to one embodiment.

[0016] Figure 2A-2C This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0017] Figure 3A and 3B This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0018] Figure 4A and 4B This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0019] Figures 5A-5D This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0020] Figure 6A and 6B This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0021] Figure 7 This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0022] Figure 8A and 8B This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0023] Figure 9A and 9B This is a schematic diagram of a porous gas bearing with a damping system according to one embodiment.

[0024] The same reference number always represents the same part. Detailed Implementation

[0025] This disclosure generally relates to bearings for heating, ventilation, air conditioning and refrigeration (HVACR) systems. More specifically, this disclosure relates to porous gas bearings for compressors in HVACR systems.

[0026] Porous gas bearings, as used in this specification, typically comprise a porous material layer on a bearing surface, which includes a uniformly distributed fluid flow on the porous surface. In one embodiment, the fluid flow may be a gas. In another embodiment, the fluid flow may be a mixture of gas and liquid.

[0027] In one embodiment, a porous gas bearing can be used in place of hydrodynamic oil bearings, ball bearings, magnetic bearings, etc. Specifically, porous gas bearings can be used in compressors (e.g., centrifugal compressors, etc.) of HVACR systems that provide a lubricant-free system. Typically, porous gas bearings can provide limited damping due to the relatively low viscosity of the working fluid. Various damping systems that can address the limited damping of porous gas bearings are disclosed in the embodiments disclosed herein. Additionally, embodiments disclosed herein may include porous gas bearings utilizing a refrigerant as the working fluid, which can increase the viscosity of the working fluid and, for example, provide favorable heat transfer properties to reduce the likelihood of bearing seizure due to thermal expansion of the shaft supported by the porous gas bearing.

[0028] Figure 1 This is a schematic diagram of a refrigerant circuit 10 according to one embodiment. The refrigerant circuit 10 typically includes a compressor 12, a condenser 14, an expansion device 16, and an evaporator 18.

[0029] Refrigerant circuit 10 is an example and can be modified to include additional components. For example, in one embodiment, refrigerant circuit 10 may include other components such as, but not limited to, an economizer heat exchanger, one or more flow control devices, a receiving tank, a dryer, a wicking heat exchanger, and so on.

[0030] Refrigerant circuit 10 can typically be used in various systems that control environmental conditions (e.g., temperature, humidity, air quality, etc.) in a controlled space (often referred to as a regulated space). Examples of such systems include, but are not limited to, HVACR systems, transport refrigeration systems, and so on.

[0031] The compressor 12, condenser 14, expansion unit 16, and evaporator 18 are fluidly connected via refrigerant lines 20, 22, and 24. In one embodiment, refrigerant lines 20, 22, and 24 may alternatively be referred to as refrigerant pipes 20, 22, and 24, etc.

[0032] In one embodiment, the refrigerant circuit 10 may be configured as a cooling system (e.g., an air conditioning system) capable of operating in a cooling mode. In another embodiment, the refrigerant circuit 10 may be configured as a heat pump system capable of operating in both a cooling mode and a heating / defrosting mode.

[0033] The refrigerant circuit 10 can operate according to generally known principles. The refrigerant circuit 10 can be configured to heat or cool a gaseous process fluid (e.g., a heat transfer medium or fluid, such as, but not limited to, air), in which case the refrigerant circuit 10 can typically represent an air conditioner or a heat pump.

[0034] In operation, compressor 12 compresses a working fluid (e.g., a heat transfer fluid such as a refrigerant) from a relatively low-pressure gas to a relatively high-pressure gas. In one embodiment, compressor 12 may be a centrifugal compressor. In one embodiment, the centrifugal compressor may operate at different speed ranges based on, for example, the size and type of the compressor. For example, in one embodiment, the centrifugal compressor may operate at 10,000 rpm or about 10,000 rpm to 150,000 rpm or about 150,000 rpm. In one embodiment, compressor 12 may be a screw compressor, a scroll compressor, etc.

[0035] A relatively high-pressure gas, also at a relatively high temperature, is discharged from compressor 12 and flows through refrigeration line 20 to condenser 14. The working fluid flows through condenser 10 and dissipates heat to the process fluid (e.g., water, air, etc.), thereby cooling the working fluid. The cooled working fluid, now in liquid form, flows through refrigeration line 22 to expansion device 16. Expansion device 16 reduces the pressure of the working fluid. As a result, a portion of the working fluid transforms into a gaseous state. The working fluid, now in a mixture of liquid and gas, flows through the remainder of refrigeration line 22 to evaporator 18. The working fluid flows through evaporator 18 and absorbs heat from the process fluid (e.g., water, air, etc.), heating the working fluid and transforming it into a gaseous state. The gaseous working fluid then returns to compressor 12 via refrigeration line 24. The above process continues when the refrigerant circuit is operating, for example, in cooling mode (e.g., when compressor 12 is activated).

[0036] In the illustrated embodiment, the first fluid line 26 may be connected at a location where fluid can be drawn from the compressor 12 and supplied to the porous gas bearing in the compressor 12. In one embodiment, the fluid line 26 is connected at a location where the fluid supplied to the porous gas bearing is gaseous or substantially gaseous. According to the following... Figure 2A-9B An embodiment of the porous gas bearing will be discussed in more detail. A second fluid line 28 may be connected to a location where fluid can be drawn from the refrigerant line 22 and supplied to the porous gas bearing. In one embodiment, the fluid line 28 may be connected where the fluid supplied to the porous gas bearing is in a mixed state, comprising at least a portion of liquid and at least a portion of gas. It should be understood that the first fluid line 26 may be included in the refrigerant circuit 10, or the second fluid line 28 may be included in the refrigerant circuit 10, or both the first fluid line 26 and the second fluid line 28 may be included in the refrigerant circuit 10.

[0037] Figure 2A-2C This is a schematic diagram of a porous gas bearing 30 with a damping system according to one embodiment. Figure 2A This is an axial cross-section of a porous gas bearing 30 according to one embodiment. Figure 2B This is a view of the inner surface of a porous gas bearing 30 according to one embodiment, if unfolded. Figure 2C The axial cross section of a porous gas bearing 30, according to one embodiment, includes modifications to the damping system.

[0038] Figure 2A-2C The porous gas bearing 30 in the middle can be used in the refrigerant circuit of an HVACR system (e.g., Figure 1 The compressor (e.g., in the refrigerant circuit 10) of the refrigerant circuit 10. Figure 1 In the compressor 12).

[0039] The porous gas bearing 30 with a damping system includes a housing 34, a porous surface layer 36, and a damper 38 formed within the housing 34.

[0040] A porous surface layer 36 extends from a first end of the housing 34 to a second end of the housing 34. In the illustrated embodiment, the porous surface layer 36 includes a plurality of segments 36A-36C. Each segment 36A-36C is spaced apart from another segment 36A-36C. The opposite ends of the respective segments 36A and 36B are longitudinally spaced apart from each other. The opposite ends of the respective segments 36B and 36C are longitudinally spaced apart from each other. These segments are separated by circumferential grooves 50 in which dampers 38 are formed. (See...) Figure 2B It should be understood that the number and size of sections 36A-36C can vary. The number and size of sections 36A-36C can be selected to provide optional damping and optional stiffness for the porous gas bearing 30. In one embodiment, the porous surface layer 36 can be made of a porous carbon graphite material. In one embodiment, the porous surface layer 36 can be any suitable porous material to achieve the functions described in this specification. In one embodiment, the porosity of the material can vary based on application and operating conditions. In one embodiment, the porous surface layer 36 may have a porosity of 10% or about 10% to 30% or about 30%.

[0041] The porous surface layer 36 is in fluid communication with the fluid inlet 40. It should be understood that the number of fluid inlets 40 can be based on the number of segments 36A-36C of the porous surface layer 36. That is, in the illustrated embodiment, there are three fluid inlets 40A, 40B, and 40C, corresponding to the porous surface layers 36A, 36B, and 36C. In one embodiment, a single fluid inlet 40 may exist, which is diverted to supply the porous surface layer 36. According to the following... Figure 7 Such embodiments are shown and described.

[0042] Shaft 42 may be disposed within bore 44 of housing 34. Shaft 42 includes a longitudinal axis LL extending along its length. In one embodiment, the gap between shaft 42 and porous surface layer 36 may be 2 micrometers or approximately 2 micrometers to 100 micrometers or approximately 100 micrometers. A larger gap implies lower stiffness and greater leakage through porous gas bearing 30. The choice of gap may depend, for example, on the required stiffness of the rotor bearing system. Radial direction R is shown in the figure. During operation, shaft 42 rotates about longitudinal axis LL. Shaft 42 is deflected in the radial direction R. To reduce the amount of movement in the radial direction R, damper 38 of the damping system may receive fluid F from the displacement of shaft 42.

[0043] The damper 38 includes a damper inlet 46 and a damper chamber 48. The damper 38 is located in... Figure 2AThe image shows the elements being fluidly separated. It should be understood that the damper 38 may be fluidly connected. The damper inlet 46 and the damper chamber 48 are sized (e.g., selected volume, etc.) to provide a selected amount of damping.

[0044] In one embodiment, the damper 38 may be configured differently at different locations along the longitudinal axis LL of the shaft 42. In one embodiment, this may provide selective damping, for example, at a specific location on the shaft 42 where it may experience more radial movement than at other locations on the shaft 42.

[0045] In one embodiment, the damper 38 can be machined into the housing 34 through the bore 44. In one embodiment, it may be relatively simple to manufacture the damper 38 by machining the housing 34 radially outward toward the bore 44. In such an embodiment, the housing 34 can be mechanically covered to prevent fluid from escaping from the damper 38. For example, refer to... Figure 2C Bolt 59 can be inserted into damping chamber 48. In such an embodiment, the volume of damper chamber 48 can be determined based on the distance at which bolt 59 is inserted into damper chamber 48.

[0046] refer to Figure 2B The damper 38 can be disposed in the circumferential groove 50, which is located between sections 36A-36C of the porous surface layer 36.

[0047] During operation, a fluid flow F is supplied from fluid source 52. Fluid source 52 may include, for example, a refrigerant circuit (e.g., Figure 1 The fluid source 52 is the fluid transferred from the refrigerant circuit 10 in the refrigerant circuit. In one embodiment, the fluid source 52 may be a source separate from the fluid in the refrigerant circuit 10.

[0048] In one embodiment, fluid can be transferred from a location through which a two-phase mixture (e.g., gas and liquid) is supplied to fluid inlet 40. In such an embodiment, the two-phase mixture can reduce the heat generated by the porous gas bearing 30. In one embodiment, reducing heat can, for example, reduce the likelihood of bearing seizure caused by thermal growth of the shaft 42. In one embodiment, the two-phase mixture can also increase the viscosity of the working fluid of the porous gas bearing 30, thereby increasing the load capacity of the porous gas bearing 30.

[0049] In one embodiment, the fluid flow F is considered to provide suitable pressure to form a fluid layer 54 between the shaft 42 and the porous surface layer 36. It should be understood that the pressure of the fluid flow F is more important than the flow rate of the fluid flow. In one embodiment, the pressure of the fluid flow F may be based on a compressor (e.g., Figure 1The discharge pressure of the compressor 12. A specific pressure can be selected based on the dimensions (e.g., weight) of the rotor and impeller assembly of the compressor 12. A minimum pressure can be determined based on when the rotor and impeller assembly rise from the porous gas bearing 30 (e.g., spaced apart). It should be understood that the pressure of the fluid flow F can depend on the refrigerant type and the compressor operating range. Examples of typical refrigerant pressure ranges may include, but are not limited to: for R-134a, 2 bar or about 2 bar to 24 bar or about 24 bar; for R-410A, 4 bar or about 4 bar to 55 bar or about 55 bar; for R-1234ze, 1 bar or about 1 bar to 20 bar or about 20 bar; for R-513A, 2 bar or about 2 bar to 24 bar or about 24 bar; for R-1233zd, 0.5 bar or about 0.5 bar to 3.5 bar or about 3.5 bar.

[0050] See you again Figure 2C The damper chamber 48 may also be provided with an orifice 56. The orifice 56 may include an aperture 58, the size of which is chosen to allow fluid F to escape from the damper chamber 48. This can, for example, prevent overpressure in the damper chamber 48. It should be understood that the orifice 56 and aperture 58 are optional and may not be included in the housing 34. If included, the aperture 58 connects the fluid to the fluid source 52, allowing fluid exiting the aperture to return to the fluid source 52.

[0051] Figure 3A and 3B A porous gas bearing 60 with a damping system according to one embodiment is shown. Figure 3A It is the axial cross section of the porous gas bearing 60 along the longitudinal axis LL of shaft 42. Figure 3B This is the radial cross-section of the porous gas bearing 60. Unless otherwise specified, it will be outlined. Figure 3A and 3B .

[0052] The features of the porous gas bearing 60 can be the same as those of the porous gas bearing 30 ( Figure 2A The features of (2B) are the same or similar. These features are labeled with the same figures and are generally not described in detail elsewhere.

[0053] In the illustrated embodiment, the damping system includes a biasing member 64 disposed in the channel 62. In one embodiment, the biasing member 64 may be a spring 64. In one embodiment, the spring 64 may include a wave spring 64. In one embodiment, the spring 64 may be mounted under tension in the porous gas bearing 60. The preload tension of the spring 64 can be selected to control the amount of damping provided by the spring 64 when using the porous gas bearing 60.

[0054] A porous gas bearing 60 with a damping system includes a housing 34. In the illustrated embodiment, the housing 34 may include a first segment 34A and a second segment 34B. The first segment 34A may be disposed radially outside the second segment 34B (relative to the shaft 42). A damping system (e.g., a biasing member 64) is disposed between the first segment 34A and the second segment 34B of the housing 34.

[0055] like Figure 3B As shown, in one embodiment, the first segment 34A of the housing 34 may include a retainer 66. In one embodiment, the retainer 66 may be a notch 66. An end of the biasing member 64 may be inserted into the retainer 66. The arrangement of the biasing member 64 in the retainer 66 may, for example, prevent the biasing member 64 from moving (e.g., rotating, etc.) about the longitudinal axis LL. It should be understood that the retainer 66 may be optional. In one embodiment, if the retainer 66 is not present, the spring may move within the housing 34. However, because the biasing member 64 may be preloaded, movement within the housing 34 may be minimized.

[0056] During operation, shaft 42 rotates about the longitudinal axis LL. Shaft 42 is deflected in the radial direction R. To reduce the amount of movement in the radial direction R, the biasing member 64 of the damping system can absorb the force (e.g., compression) from the displacement of shaft 42 in the radial direction R.

[0057] Multiple O-rings 68 are disposed at the ends of housing 34 to fluid-seal passage 62. In one embodiment, the O-rings 68 can provide damping if the biasing member 64 is compressed. In one embodiment, the O-rings 68 can also accommodate slight misalignment between bearings located at different positions on shaft 42.

[0058] According to one embodiment, the damping system of the porous gas bearing 60 and the damping system of the porous gas bearing 30 can be combined in a single embodiment to include a damper 38 and a biasing member 64.

[0059] Figure 4A and 4B A porous gas bearing 80 with a damping system according to one embodiment is shown. Figure 4A It is the axial cross section of the porous gas bearing 80 along the longitudinal axis LL of shaft 42. Figure 4B This is the radial cross-section of the porous gas bearing 80. Unless otherwise specified, it will be outlined. Figure 4A and 4B .

[0060] The features of the porous gas bearing 80 can be compared with those of the porous gas bearing 30. Figure 2A Features of 2B, 2C) and porous gas bearing 60 ( Figure 3A The features of 3B) are the same or similar.

[0061] In the illustrated embodiment, the damping system includes a plurality of biasing members 84. In one embodiment, the plurality of biasing members 84 may include a plurality of O-rings 84. In one embodiment, the plurality of O-rings 84 may include two O-rings 84. It should be understood that the number of biasing members 84 may vary depending on the desired amount of damping provided by the damping system.

[0062] A porous gas bearing 80 with a damping system includes a housing 34. In the illustrated embodiment, the housing 34 includes a first segment 34A and a second segment 34B. The first segment 34A may be disposed radially outward of the second segment 34B (relative to the shaft 42). A damping system (e.g., a biasing member 84) is disposed between the first segment 34A and the second segment 34B of the housing 34.

[0063] like Figure 4A As shown, the second section 34B of the housing 34 may include a plurality of retainers 86 (e.g., recesses 86). The plurality of retainers 86 can provide a fixed position for positioning the biasing member 84 and prevent the biasing member 84 from moving axially (e.g., in a direction parallel to the longitudinal axis LL). In one embodiment, the biasing member 84 may be made of a material compatible with refrigerants and refrigerant lubricants. Examples of suitable materials include, but are not limited to, epichlorohydrin, nitrile, neoprene, fluororubber, etc.

[0064] According to one embodiment, the damping system of the porous gas bearing 80 and the damping systems of one or more porous gas bearings 30 and 60 may be combined in a single embodiment to include a damper 38, a bias member 64, and a bias member 84.

[0065] Figures 5A-5D A porous gas bearing 100 with a damping system according to one embodiment is shown. Figure 5A It is the axial cross section of the porous gas bearing 100 along the longitudinal axis LL of shaft 42. Figure 5B It is the radial cross-section of the porous gas bearing 100. Figure 5C It is a porous gas bearing 100 and Figure 5D The damping system is located along the longitudinal axis LL of shaft 42 in the axial cross section. Figure 5D This is the radial cross-section of a porous gas bearing 100 with an improved damping system. Unless otherwise specified, it will be outlined. Figure 5A and 5B And will outline Figure 5C and 5D .

[0066] The features of the porous gas bearing 100 can be the same as those of the porous gas bearing 30. Figure 2A Features of 2B), porous gas bearing 60 ( Figure 3AFeatures of 3B) and porous gas bearing 80 ( Figure 4A The features of 4B) are the same or similar.

[0067] refer to Figure 5A and 5B The damping system shown includes multiple damping structures 104A. The damping structure 104A can also be referred to as a squeeze diaphragm 104A. In the damping system shown, the damping structure 104A is an hermetically sealed damping structure 104A. Four damping structures 104A are shown. It should be understood that the number of damping structures 104A can vary.

[0068] The damping structure 104A has a shell 106A, within which a fluid 108A is filled. The shell 106A is flexible. The flexibility of the shell 106A and the characteristics of the fluid 108A within the shell 106A determine the stiffness of the damping structure 104A. Figure 5A and 5B The possible damping amounts of the damping system in the figure. Stiffness and damping can depend on several factors, such as, but not limited to, bearing size, bearing clearance, etc. In one embodiment, the damping structure 104A may have a damping value ranging from 10, depending on the bearing clearance and size. 6 MN / m or approximately 10 6 MN / m to 10 8 MN / m or approximately 10 8 The stiffness coefficient is MN / m and 10 N*s / m or approximately 10 N*s / m to 6 x 10. 5 N*s / m or approximately 6x10 5 Damping coefficient in N*s / m.

[0069] refer to Figure 5C and 5D The damping system shown includes multiple damping structures 104B. The damping structure 104B can also be referred to as a squeeze diaphragm 104B. In the damping system shown, the damping structure 104B is not an hermetically sealed damping structure 104B. Four damping structures 104B are shown. It should be understood that the number of damping structures 104B can vary.

[0070] The damping structure 104B has a housing 106B, within which fluid 108B is filled. Figure 5A and 5BUnlike the damping structure 104A, damping structure 104B includes a fluid inlet 110 and an orifice 112. Fluid 108B is supplied to the housing 106B. In one embodiment, fluid 108B may be the same as the fluid F supplied to the porous gas surface 36. In such an embodiment, fluid 108B may be a refrigerant. It should be understood that fluid inlet 110 allows fluid to both enter and exit orifice 112.

[0071] The shell 106B is flexible. The flexibility of the shell 106B, along with the properties of the fluid 108B, the quantity of fluid 108B, and the pressure of the fluid 108B within the shell 106B, can determine the stiffness of the damping structure 104B. The stiffness of the damping structure 104B can be determined. Figure 5C and 5D The possible damping amount of the damping system in the middle. The damping structure 104B can be fed by fluid 108B into the shell 106B with variable stiffness.

[0072] According to one embodiment, Figures 5A-5D The damping system of the porous gas bearing 100 and the damping systems of the porous gas bearings 30, 60 and 80 can be combined in a single embodiment to include a damper 38, a bias member 64, a bias member 84 and a damping structure 104A or 104B.

[0073] Figure 6A and 6B A porous gas bearing 120 with a damping system according to one embodiment is shown. Figure 6A It is the axial cross section of the porous gas bearing 120 along the longitudinal axis LL of shaft 42. Figure 6B This is the radial cross-section of the porous gas bearing 120. Porous gas bearing 120 and... Figure 3A , 3B The porous gas bearing 60 and damping system 62 are essentially the same. Unless otherwise specified, they will be outlined below. Figure 6A and 6B .

[0074] In the illustrated embodiment, the porous surface layer 36 includes a plurality of grooves 124. The grooves 124 are radially formed around the porous gas bearing 120. The grooves 124 extend axially within the porous gas bearing 120. The grooves 124 prevent fluid swirling.

[0075] Figure 7 This is a schematic diagram of a porous gas bearing 140 with a damping system according to one embodiment. Figure 7 This is an axial cross-sectional view of a porous gas bearing 140 according to one embodiment.

[0076] Figure 7The porous gas bearing 140 in the middle can be used in the refrigerant circuit of an HVACR system (e.g., Figure 1 The compressor (e.g., in the refrigerant circuit 10) of the refrigerant circuit 10. Figure 1 In the compressor 12).

[0077] Porous gas bearing 140 and Figure 2A , 2B The porous gas bearing 30 is basically the same as that in the porous gas bearing 140. In the porous gas bearing 140, the damping system includes... Figure 2A-5D The damping system is a combination of components. In the porous gas bearing 140, damper 38 is included together with an additional damper 142. The additional damper 142 can be selected from... Figure 3A-5D The damping system described herein. Therefore, damper 142 may include one or more of spring 64, O-ring 84, damping structure 104A, or damping structure 104B. In one embodiment, groove 124 ( Figure 6A ,6B) can be included in the porous gas bearing 140.

[0078] Figure 8A and 8B This is a schematic diagram of a porous gas bearing 160 with a damping system according to one embodiment.

[0079] Figure 8A It is the axial cross section of the porous gas bearing 160 along the longitudinal axis LL of shaft 42. Figure 8B This is the radial cross-section of the porous gas bearing 160. Unless otherwise specified, it will be outlined. Figure 8A and 8B .

[0080] The features of the porous gas bearing 160 can be compared with those described above. Figures 2A-7 The porous gas bearings shown and described have the same or similar features. These features are identified by the same reference numerals.

[0081] In the illustrated embodiment, the housing 34 is modified to include a plurality of holes 162 in fluid communication with channels 164. The holes 162 extend at an angle to the porous surface layer 36, the angle being oriented to provide fluid F in a direction opposite to the rotational direction of the shaft 42. Providing fluid F at such an angle can, for example, reduce the instability of the shaft 42, and thus reduce the amount of radial movement of the shaft R.

[0082] Figure 9A and 9B This is a schematic diagram of a porous gas bearing 200 with a damping system according to one embodiment.

[0083] Figure 9A It is the axial cross section of the porous gas bearing 200 along the longitudinal axis LL of shaft 42. Figure 9B This is the radial cross-section of the porous gas bearing 200. Unless otherwise specified, it will be outlined. Figure 9A and 9B .

[0084] The features of the porous gas bearing 200 can be compared with those described above. Figure 2A-7 The porous gas bearings shown and described have the same or similar features. These features are labeled with the same reference numerals.

[0085] In the illustrated embodiment, the damping system includes a damper 202 disposed in channel 204. In one embodiment, damper 202 may include a wire mesh material. The wire mesh material may be made of metal or plastic. The wire mesh material may be woven to form a mesh structure. Knitted material may provide elasticity. The wire mesh material may be included in channel 204 such that it can absorb movement of shaft 42 in the radial direction R. Damper 202 may be a relatively inexpensive alternative to the damping structure 104 (e.g., extruded membrane) in porous gas bearing 200. The material of the wire mesh material used for damper 202 may be selected such that specific damping can be provided in porous gas bearing 200. Suitable materials include, but are not limited to, steel, steel alloys, aluminum, copper, nickel alloys, titanium alloys, nylon, polyethylene, etc.

[0086] According to one embodiment, the damping system of the porous gas bearing 200 and Figure 2A-7 The damping system of the porous gas bearing in the embodiment can be combined in a single embodiment to include damper 38, bias member 64, bias member 84, and damper 202.

[0087] aspect

[0088] It should be understood that any one of aspects 1-9 can be combined with any one of aspects 10-15, 16-20, 21-29, 30-35, and 36-40. Any one of aspects 10-15 can be combined with any one of aspects 16-20, 21-29, 30-35, and 36-40. Any one of aspects 16-20 can be combined with any one of aspects 21-29, 30-35, and 36-40. Any one of aspects 21-29 can be combined with any one of aspects 30-35 and 36-40. Any one of aspects 30-35 can be combined with any one of aspects 36-40.

[0089] Aspect 1. A porous gas bearing, comprising: a housing having a fluid inlet and a hole; a porous surface layer disposed within the housing and surrounding the hole in a circumferential direction, the porous surface layer including a plurality of segments arranged longitudinally along the hole, the porous surface layer being in fluid communication with the fluid inlet; and a damping system including a plurality of dampers arranged circumferentially around the hole, wherein the plurality of dampers are disposed between a first segment and a second segment of the plurality of segments of the porous surface layer.

[0090] Aspect 2. The porous gas bearing according to aspect 1, wherein the fluid inlet is fluidly connected to the refrigerant circuit.

[0091] Aspect 3. The porous gas bearing according to Aspect 2, wherein the fluid inlet is fluidly connected to the refrigerant circuit at a location between the condenser and the expansion device in the refrigerant circuit or at the discharge location of the compressor in the refrigerant circuit.

[0092] Aspect 4. The porous gas bearing according to any one of aspects 1-3 further includes a plurality of grooves located in the porous surface layer.

[0093] Aspect 5. The porous gas bearing according to any one of aspects 1-4, wherein the plurality of dampers includes a damper inlet and a damper chamber, the damper inlet being disposed at the orifice and the damper chamber being disposed radially outside the damper inlet.

[0094] Aspect 6. The porous gas bearing according to any one of aspects 1-5, wherein the porous surface layer is made of a carbon-graphite material.

[0095] Aspect 7. The porous gas bearing according to any one of aspects 1 to 6, wherein the plurality of dampers includes a damper inlet and a damper chamber, the damper inlet being disposed at the orifice, and the damper chamber being disposed radially outside the damper inlet, and the damper chamber being covered.

[0096] Aspect 8. The porous gas bearing according to any one of aspects 1 to 7, wherein the plurality of dampers includes a damper inlet and a damper chamber, the damper inlet being disposed at the orifice, and the damper chamber being disposed radially outside the damper inlet, and the damper chamber including a fluid outlet and an orifice located in the fluid outlet, the fluid outlet being disposed radially outward from the orifice relative to the damper chamber.

[0097] Aspect 9. The porous gas bearing according to any one of aspects 1-8, wherein the damping system further comprises one or more of a spring, an O-ring, a diaphragm, and a wire mesh.

[0098] Aspect 10. A refrigerant circuit comprising: a compressor, a condenser, an expander, and an evaporator fluidly connected, wherein the compressor includes a shaft supported by a porous gas bearing, the porous gas bearing comprising: a housing having a fluid inlet and a hole; a porous surface layer disposed within the housing and circumferentially surrounding the hole, the porous surface layer including a plurality of segments arranged longitudinally along the hole, the porous surface layer being in fluid communication with the fluid inlet; and a damping system including a plurality of dampers circumferentially disposed around the hole in the housing, wherein the plurality of dampers are arranged between a first segment and a second segment of the plurality of segments of the porous surface layer.

[0099] Aspect 11. The refrigerant circuit according to aspect 10, wherein the porous gas bearing is fluidly connected to the refrigerant circuit.

[0100] Aspect 12. The refrigerant circuit according to any one of aspects 10 or 11 further includes a fluid source fluidly separated from the refrigerant circuit, the fluid source being fluidly connected to the porous gas bearing.

[0101] Aspect 13. The refrigerant circuit according to any one of aspects 10-12, wherein the damping system further comprises one or more of a spring, an O-ring, a squeeze diaphragm, and a wire mesh.

[0102] Aspect 14. The refrigerant circuit according to any one of aspects 10-13, wherein the porous gas bearing is fluidly connected to the refrigerant circuit at a location configured to receive a mixture of gas and liquid fluid from the refrigerant circuit.

[0103] Aspect 15. The refrigerant circuit according to any one of aspects 10-14, wherein the refrigerant circuit is a lubricant-free refrigerant circuit.

[0104] Aspect 16. A centrifugal compressor comprising: a rotating shaft; a porous gas bearing, the porous gas bearing comprising: a housing having a fluid inlet and a hole; a porous surface layer disposed within the housing and surrounding the hole in a circumferential direction, the porous surface layer comprising a plurality of segments arranged longitudinally along the hole, the porous surface layer being in fluid communication with the fluid inlet; and a damping system comprising a plurality of dampers circumferentially disposed around the hole in the housing, wherein the plurality of dampers are arranged between a first segment and a second segment of the plurality of segments of the porous surface layer.

[0105] Aspect 17. The centrifugal compressor according to aspect 16, wherein the damping system further comprises one or more of a spring, an O-ring, a compression diaphragm, and a wire mesh.

[0106] Aspect 18. The centrifugal compressor according to any one of aspects 16 or 17, wherein the shaft is configured to rotate at 10,000 revolutions per minute or about 10,000 revolutions per minute to 150,000 revolutions per minute or about 150,000 revolutions per minute.

[0107] Aspect 19. The centrifugal compressor according to any one of aspects 16-18, wherein the porous gas bearing is a radial bearing supporting the shaft.

[0108] Aspect 20. The centrifugal compressor according to any one of aspects 16-19, wherein the plurality of dampers includes a damper inlet and a damper chamber, the damper inlet being disposed at the orifice, and the damper chamber being disposed radially outside the damper inlet.

[0109] Aspect 21. A porous gas bearing, comprising: a housing having a fluid inlet and a hole; a porous surface layer disposed within the housing and surrounding the hole in a circumferential direction, the porous surface layer being in fluid communication with the fluid inlet; and a damping system including a biasing member disposed in a channel extending along a longitudinal direction of the hole and circumferentially surrounding the hole, wherein the biasing member is arranged radially outward from the porous surface layer.

[0110] Aspect 22. The porous gas bearing according to aspect 21, wherein the fluid inlet is fluidly connected to the refrigerant circuit.

[0111] Aspect 23. The porous gas bearing according to aspect 22, wherein the fluid inlet is fluidly connected to the refrigerant circuit at a location between the condenser and the expansion device in the refrigerant circuit or at the discharge location of the compressor in the refrigerant circuit.

[0112] Aspect 24. The porous gas bearing according to any one of aspects 21-23 further includes a plurality of grooves located in the porous surface layer.

[0113] Aspect 25. The porous gas bearing according to any one of aspects 21-24, wherein the biasing member comprises a spring.

[0114] Aspect 26. The porous gas bearing according to any one of aspects 21-25, wherein the porous surface layer is made of a carbon-graphite material.

[0115] Aspect 27. The porous gas bearing according to any one of aspects 21-26, wherein the biasing member comprises a wave spring.

[0116] Aspect 28. The porous gas bearing according to any one of aspects 21-27 further includes a plurality of dampers arranged circumferentially around a hole in the housing.

[0117] Aspect 29. The porous gas bearing according to any one of aspects 21-28, the damping system further includes one or more of an O-ring, an extruded diaphragm, and a wire mesh.

[0118] Aspect 30. A refrigerant circuit comprising: a compressor, a condenser, an expander, and an evaporator fluidly connected, wherein the compressor includes a shaft supported by a porous gas bearing, the porous gas bearing including: a housing having a fluid inlet and a hole; a porous surface layer disposed within the housing and circumferentially surrounding the hole, the porous surface layer being in fluid communication with the fluid inlet; and a damping system including a biasing member disposed in a channel extending longitudinally and circumferentially around the hole, wherein the biasing member is arranged radially outward from the porous surface layer.

[0119] Aspect 31. The refrigerant circuit according to aspect 30, wherein the porous gas bearing is fluidly connected to the refrigerant circuit.

[0120] Aspect 32. The refrigerant circuit according to any one of aspects 30 or 31 further includes a fluid source fluidly separated from the refrigerant circuit, the fluid source being fluidly connected to the porous gas bearing.

[0121] Aspect 33. The refrigerant circuit according to any one of aspects 30-32, wherein the damping system further comprises one or more of an O-ring, a duct extrusion film, and a wire mesh.

[0122] Aspect 34. A refrigerant circuit according to any one of aspects 30-33, wherein the porous gas bearing is fluidly connected to the refrigerant circuit at a location configured to receive a mixture of gas and liquid fluid from the refrigerant circuit.

[0123] Aspect 35. The refrigerant circuit according to any one of aspects 30-34, wherein the refrigerant circuit is a lubricant-free refrigerant circuit.

[0124] Aspect 36. A centrifugal compressor comprising: a rotating shaft; a porous gas bearing, the porous gas bearing comprising: a housing having a fluid inlet and a hole; a porous surface layer disposed within the housing and surrounding the hole in a circumferential direction, the porous surface layer being in fluid communication with the fluid inlet; and a damping system including a biasing member disposed in a channel extending longitudinally along the hole and circumferentially around the hole, wherein the biasing member is arranged radially outward from the porous surface layer.

[0125] Aspect 37. The centrifugal compressor according to aspect 36, wherein the damping system further includes one or more of an O-ring, a squeeze diaphragm, and a wire mesh.

[0126] Aspect 38. The centrifugal compressor according to any one of aspects 36 or 37, wherein the shaft is configured to rotate at 10,000 revolutions per minute or about 10,000 revolutions per minute to 150,000 revolutions per minute or about 150,000 revolutions per minute.

[0127] Aspect 39. The centrifugal compressor according to any one of aspects 36-38, wherein the porous gas bearing is a radial bearing supporting the shaft.

[0128] Aspect 40. The centrifugal compressor according to any one of aspects 36-39, wherein the biasing member is pre-tensioned to provide a selected amount of damping.

[0129] The terminology used in this specification is intended to describe particular embodiments and is not restrictive. Unless otherwise expressly stated, the terms "a," "an," and "the" also include the plural forms. The terms "comprising" and / or "including" when used indicate the presence of the said features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, and / or components.

[0130] Regarding the foregoing description, it should be understood that changes in detail may be made without departing from the scope of this disclosure, particularly in terms of the materials used in the structure and the shape, size, and arrangement of the components. The term "embodiment" may, but does not necessarily, refer to the same embodiment. The embodiments and disclosure are merely examples. Other and further embodiments may be devised without departing from the basic scope of the invention, the true scope and spirit of which are indicated by the appended claims.

Claims

1. A porous gas bearing, comprising: A housing having a fluid inlet and an orifice; A porous surface layer is disposed within the housing and surrounds the pores circumferentially. The porous surface layer includes multiple segments arranged longitudinally along the pores, each segment being spaced apart from the other segments in the longitudinal direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system comprising multiple dampers arranged circumferentially around the hole, wherein the multiple dampers are disposed between a first segment and a second segment of the multiple segments of the porous surface layer, and the system further comprising a damper inlet disposed at the hole and a damper chamber disposed radially outward from the damper inlet. At least one of the following must be met: The damping chamber is covered, or Multiple dampers include a fluid outlet of a damping chamber and an orifice in the fluid outlet, the fluid outlet being arranged radially outward from the orifice relative to the damping chamber.

2. The porous gas bearing according to claim 1, characterized in that, The fluid inlet is fluidly connected to the refrigerant circuit.

3. The porous gas bearing according to claim 2, characterized in that, The fluid inlet is fluidly connected to the refrigerant circuit at a location between the condenser and the expansion device in the refrigerant circuit or at the discharge location of the compressor in the refrigerant circuit.

4. The porous gas bearing according to claim 1, characterized in that, It also includes multiple grooves located in the porous surface layer.

5. The porous gas bearing according to claim 1, characterized in that, The porous surface layer is made of carbon-graphite material.

6. The porous gas bearing according to claim 1, wherein the damping chamber is covered.

7. The porous gas bearing of claim 1, wherein the plurality of dampers includes a fluid outlet for the damper chamber and an orifice in the fluid outlet, the fluid outlet being disposed radially outward from the orifice relative to the damper chamber.

8. The porous gas bearing according to claim 1, wherein the damping system further comprises one or more of a spring, an O-ring, a compression diaphragm, and a wire mesh disposed between a first section and a second section of the housing, wherein, The second section is located radially inside the first section.

9. A refrigerant circuit, comprising: The compressor, condenser, expander, and evaporator are fluidly connected. The compressor includes a shaft supported by a porous gas bearing, the porous gas bearing comprising: A housing having a fluid inlet and an orifice; A porous surface layer is disposed within the housing and surrounds the pores circumferentially. The porous surface layer includes multiple segments arranged longitudinally along the pores, each segment being spaced apart from the other segments in the longitudinal direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system comprising multiple dampers circumferentially arranged around a hole in the housing, wherein the multiple dampers are disposed between a first segment and a second segment of a plurality of sections of the porous surface layer. And multiple dampers, including a damper inlet located at the orifice and a damper chamber located radially outward from the damper inlet. At least one of the following must be met: The damping chamber is covered, or Multiple dampers include a fluid outlet of a damping chamber and an orifice in the fluid outlet, the fluid outlet being arranged radially outward from the orifice relative to the damping chamber.

10. The refrigerant circuit of claim 9, wherein the porous gas bearing is fluidly connected to the refrigerant circuit.

11. The refrigerant circuit according to claim 9, characterized in that, It also includes a fluid source, which is fluidly separated from the refrigerant circuit and is fluidly connected to the porous gas bearing.

12. The refrigerant circuit according to claim 9, characterized in that, The damping system further includes one or more of a spring, an O-ring, a diaphragm, and a wire mesh arranged between a first section and a second section of the housing, wherein the second section is located radially inside the first section.

13. The refrigerant circuit according to claim 9, characterized in that, The porous gas bearing is fluidly connected to the refrigerant circuit at a location configured to receive a mixture of gas and liquid fluid from the refrigerant circuit.

14. The refrigerant circuit according to claim 9, characterized in that, The refrigerant circuit is a lubricant-free refrigerant circuit.

15. A centrifugal compressor, comprising: A rotating axis; and Porous gas bearing, the porous gas bearing comprising: A housing having a fluid inlet and an orifice; A porous surface layer is disposed within the housing and surrounds the pores circumferentially. The porous surface layer includes multiple segments arranged longitudinally along the pores, each segment being spaced apart from the other segments in the longitudinal direction. The porous surface layer is in fluid communication with the fluid inlet. A damping system comprising multiple dampers circumferentially arranged around a hole in a housing, wherein the multiple dampers are disposed between a first section and a second section of a plurality of segments of a porous surface layer, and the system further comprises multiple dampers including a damper inlet disposed at the hole and a damper chamber disposed radially outward from the damper inlet. One of the following must be met: The damping chamber is covered, or Multiple dampers include a fluid outlet of a damping chamber and an orifice in the fluid outlet, the fluid outlet being arranged radially outward from the orifice relative to the damping chamber.

16. The centrifugal compressor according to claim 15, wherein, The damping system further includes one or more of a spring, an O-ring, a compression diaphragm, and a wire mesh disposed between a first section and a second section of the housing, wherein... The second section is located radially inside the first section.

17. The centrifugal compressor according to claim 15, characterized in that, The shaft is configured to rotate at 10,000 revolutions per minute or from 10,000 revolutions per minute to 150,000 revolutions per minute or 150,000 revolutions per minute.

18. The centrifugal compressor according to claim 15, characterized in that, The porous gas bearing is a radial bearing that supports the shaft.

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