Electric compressor device having air bearing with reduced axial and radial buildup

Abstract

A turbine includes a housing assembly having a first housing member with a shroud surface, a bearing housing, and a second housing member. The turbine also includes a bearing that supports the rotation of a rotating group within the housing assembly. The first housing member has a first axial surface, and the bearing housing has a second axial surface that is substantially flush with the first axial surface. The second housing member has a third axial surface that faces in an axial direction opposite to the axial direction of the first and second axial surfaces. The first housing member has a first radial surface, and the bearing housing has a second radial surface. The first housing member and the bearing housing are attached to the second housing member. The first and second axial surfaces abut the third axial surface, and the first radial surface abuts the second radial surface.

Description

Technical Field

[0001] The present disclosure relates generally to a compressor and, more particularly, to an electric compressor apparatus having an air bearing with reduced axial and radial buildup. Background Art

[0002] A turbine typically consists of a casing and a rotating group housed within it. The rotating group includes an impeller positioned against the shroud surface of the casing, defining a fluid gap between them. During turbine operation, the fluid gap receives fluid flow. The fluid gap is a critical characteristic, as it influences turbine performance. In many cases, a smaller fluid gap results in increased efficiency during operation.

[0003] However, certain issues exist with the manufacturing and / or design of these turbines. For example, turbines comprise multiple components, and the assembly of these components can result in excessive tolerance stacking. Tolerance stacking represents the worst-case cumulative effect of component tolerances relative to the assembly. Because fluid clearance is a critical characteristic of a turbine, the assembly's tolerance stacking is compared to the available fluid clearance between the impeller of the rotating assembly and the shroud surface of the casing. In some cases, if the tolerance stacking is excessive, the fluid clearance may become larger, which can adversely affect the performance of the turbine.

[0004] Therefore, it is desirable to provide a turbine with reduced tolerance stack-up. It is also desirable that the turbine be compact and highly manufacturable. Other desirable features and characteristics of the present disclosure will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background discussion. Summary of the Invention

[0005] In one embodiment, a turbine is disclosed that includes a housing assembly. The housing assembly includes a first housing member having a shroud surface, a bearing housing, and a second housing member. The turbine also includes a rotating group having an impeller positioned opposite the shroud surface, defining a fluid gap between the impeller and the shroud surface. The turbine also includes a bearing that supports the rotating group for rotation about a rotation axis within the housing assembly. At least a portion of the bearing is housed by the bearing housing. The first housing member has a first axial surface, and the bearing housing has a second axial surface that is substantially flush with the first axial surface. The second housing member has a third axial surface that faces in an axial direction opposite to the axial directions of the first and second axial surfaces. The first housing member has a first radial surface, and the bearing housing has a second radial surface. The first and second radial surfaces face in opposite radial directions relative to the rotation axis. The first housing member and the bearing housing are attached to the second housing member, defining a fluid gap between the impeller and the shroud surface. The first and second axial surfaces abut the third axial surface, and the first radial surface abuts the second radial surface.

[0006] In another embodiment, an electric compressor device is disclosed that includes a housing assembly. The housing assembly includes a compressor housing having a shroud surface, a bearing housing, and a motor housing. The compressor device also includes a rotating assembly having a compressor impeller, the compressor impeller opposing the shroud surface to define a fluid gap therebetween. Furthermore, the compressor device includes an air bearing that supports the rotating assembly for rotation about a rotation axis within the housing assembly. At least a portion of the air bearing is housed by the bearing housing. The compressor device also includes an electric motor housed within the motor housing. The electric motor is configured to drive the rotating assembly to rotate within the housing assembly. The compressor housing has a first axial surface, and the bearing housing has a second axial surface that is substantially flush with the first axial surface. The motor housing has a third axial surface that faces in an axial direction opposite to the axial directions of the first and second axial surfaces. The compressor housing has a first radial surface, and the bearing housing has a second radial surface. The first and second radial surfaces face in opposite radial directions relative to the rotation axis. The compressor housing and the bearing housing are attached to the motor housing, with the fluid gap defined between the compressor impeller and the shroud surface. The bearing housing at least partially encloses the electric motor within the motor housing. The first and second axial surfaces abut the third axial surface, and the first radial surface abuts the second radial surface.

[0007] In yet another embodiment, a method for manufacturing a turbine is disclosed. The method includes attaching a first housing member having a shroud surface to a second housing member in which a rotating group is disposed. The rotating group has an impeller positioned opposite the shroud surface to define a fluid gap therebetween. The method also includes attaching a bearing housing to the second housing member. A bearing is at least partially housed by the bearing housing. The bearing supports rotation of the rotating group about a rotational axis. The first housing member has a first axial surface, and the bearing housing has a second axial surface substantially flush with the first axial surface. The second housing member has a third axial surface facing in an axial direction opposite to the axial directions of the first and second axial surfaces. The first housing member has a first radial surface, and the bearing housing has a second radial surface. The first and second radial surfaces face in opposite radial directions relative to the rotational axis. The first housing member and the bearing housing are attached to the second housing member, defining a fluid gap between the impeller and the shroud surface. The first and second axial surfaces abut the third axial surface, and the first radial surface abuts the second radial surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure will be described below with reference to the following drawings, wherein like reference numerals represent like elements, and wherein:

[0009] Figure 1is a schematic diagram of a fuel cell system having an electric compressor device according to an exemplary embodiment of the present disclosure;

[0010] Figure 2 yes Figure 1 Detailed cross-sectional view of the compressor unit;

[0011] Figure 3 yes Figure 1 A detailed cross-sectional view of the compressor assembly; and

[0012] Figure 4 yes Figure 1 Exploded cross-sectional view of the compressor unit. DETAILED DESCRIPTION

[0013] The following detailed description is merely exemplary in nature and is not intended to limit the disclosure or the application and uses of the disclosure. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description.

[0014] Broadly, exemplary embodiments disclosed herein include a turbine having a housing and a rotating group housed therein. The rotating group has an impeller that opposes a shroud surface of the housing and defines a fluid gap between the impeller and the shroud surface. The turbine of the present disclosure has a relatively low number of components, and the tolerance stack-up of these components when assembled together is relatively low. Specifically, there are relatively few components that affect the radial and / or axial positioning of the impeller relative to the shroud surface. Therefore, variability between components has a smaller effect on the size of the fluid gap. In addition, the manufacturability of the turbine is thereby increased. Ultimately, more efficient turbines can be produced because turbines with reduced fluid gaps can be repeatedly manufactured in large volumes.

[0015] First reference Figure 1 , a turbine 101 is shown according to an exemplary embodiment. As shown, the turbine 101 generally includes a rotating group 118 and a housing assembly 119. The rotating group 118 is supported by one or more bearings 121 for rotation within the housing assembly 119 about an axis of rotation 120.

[0016] Rotating group 118 may generally include an elongated cylindrical shaft 140 having a first end 142 and a second end 144. Rotating group 118 may also include one or more impellers, such as a compressor impeller 130 supported on first end 142 of shaft 140 and a turbine impeller 131 supported on second end 144. Housing assembly 119 includes various components that cooperatively house rotating group 118. Housing assembly 119 and rotating group 118 cooperatively define various sections of turbomachine 101, such as motor section 112, compressor section 110, and turbine section 113.

[0017] The turbine 101 can be operably connected to the fuel cell system 100 and can be configured as an electric charger or electric compressor device for the fuel cell system 100. However, it will be appreciated that the turbine 101 can be configured differently from the embodiment shown, and the turbine 101 can be incorporated into another system without departing from the scope of this disclosure. The fuel cell system 100 may include a fuel cell stack 104 comprising a plurality of fuel cells. Hydrogen can be supplied to the fuel cell stack 104 from a tank 106, and oxygen can be supplied to the fuel cell stack 104 to generate electricity through known chemical reactions. The fuel cell stack 104 can generate electricity for an electrical device such as an electric motor 105. In some embodiments, the fuel cell system 100 can be included in a vehicle, such as a car, truck, sport utility vehicle, van, motorcycle, etc. Thus, in some embodiments, the electric motor 105 can convert electrical power into mechanical power to drive and rotate the axle of the vehicle (and therefore drive and rotate one or more wheels).

[0018] Oxygen may be provided, at least in part, to the fuel cell stack 104 by the turbine 101. More specifically, the motor section 112 may drive the rotating group 118 to rotate, and the compressor section 110 may provide the compressed air flow to the intercooler 128 as it flows toward the fuel cell stack 104, and exhaust gas from the fuel cell stack 104 may be fed back to the turbine section 113 to provide power assistance to the motor section 112. However, it will be appreciated that other embodiments of the turbine 101 fall within the scope of the present disclosure. For example, in some embodiments, the turbine section 113 may be omitted, such that the turbine 101 includes the motor section 112 and the compressor section 110. Additionally, in some embodiments, the turbine 101 may include multiple sections, such as multiple compressor sections, which are serially fluidly connected to include a first (low-pressure) stage that supplies a second (high-pressure) stage, which ultimately supplies the fuel cell system 100. Additional embodiments of the turbine 101 may be provided in other systems (other than the fuel cell system 100) without departing from the scope of the present disclosure.

[0019] The components of motor section 112, compressor section 110, and turbine section 113 will now be discussed in accordance with exemplary embodiments. Figures 1-4 ; however, these are merely exemplary embodiments of the present disclosure.

[0020] The motor section 112 may include an electric motor 134 for driving the rotation of the rotating group 118 and / or converting the rotational power of the rotating group 118 into electricity. The motor 134 may generally include a rotor 136 and a stator 138 of known type. The rotor 136 may be mounted on a shaft 140, and the stator 138 may surround the rotor 136. A first end 142 and a second end 144 of the shaft 140 may extend from respective axial sides of the motor 134 and may be supported in a motor housing 150 of the housing assembly 119. The motor housing 150 may be hollow and / or may include a motor cavity 129 that receives the motor 134. In some embodiments, the motor housing 150 may include a hollow base 135 having a first open axial end 137 and a substantially closed second axial end 139 ( Figure 1 ). The open axial end 137 can be covered by other components described below to substantially close the open axial end 137 and cover and seal the motor 134 within the motor cavity 129. The motor 134 can be operably attached to the rotating group 118 for driving the rotating group 118 to rotate about the axis 120 within the housing assembly 119.

[0021] like Figures 1-4 As shown, the compressor section 110 may include a compressor wheel 130 housed within a compressor housing 152 of the housing assembly 119. The compressor housing 152 may be a unitary, one-piece component. In some embodiments, the compressor housing 152 may be manufactured via a casting operation, via an additive manufacturing process, or otherwise. At least some surfaces of the compressor housing 152 may be ground, polished, or otherwise modified to provide a predetermined surface roughness, smoothness, or other characteristics. The compressor housing 152 may include a tubular inlet 153 centered on the axis 120. The compressor housing 152 may also be hollow, and the flow path 151 may extend axially in a downstream direction and then may turn radially outward relative to the axis 120. Further downstream, the inner surface of the compressor housing 152 may define a volute passage 154 extending about the axis 120. It should be understood that the flow path 151 may vary from the illustrated embodiment and may have a variety of shapes, contours, and configurations without departing from the scope of the present disclosure.

[0022] The compressor housing 152 may include an axial face 108 that is opposite an axial face 156 of the base 135 of the motor housing 150. Portions of the axial face 108 may be attached and / or mated against the axial face 156, as will be described in detail below. At least some of the mating surfaces may be ground, polished, or otherwise modified to provide a predetermined surface roughness, smoothness, or other characteristics that ensure a secure attachment. The compressor housing 152 may be secured to the base 135 of the motor housing 150 and may overlie the front side 146 of the compressor wheel 130. The rear side 148 of the compressor wheel 130 may face the motor section 112. Thus, the compressor wheel 130 may be disposed within the compressor housing 152 and may be directly opposite a shroud surface 155 of the compressor housing 152. The shroud surface 155 may be shaped inversely to the outer contour of the compressor wheel 130. The compressor housing 152 may also include a radially inwardly facing inlet surface 181 disposed further upstream of the shroud surface 155 and the compressor wheel 130. Additionally, the compressor housing 152 may include a diffuser surface 183 disposed downstream of the shroud surface 155 and the compressor wheel 130 and axially facing the motor section 112. The volute passage 154 may be disposed downstream of the diffuser surface 183.

[0023] like Figure 2 and Figure 3 , the compressor impeller 130 may include a plurality of blades 147 opposite the shroud surface 155 of the compressor housing 152. The blades may include respective leading ends 182, trailing ends 184, and outer edges 186. Collectively, the leading ends 182, trailing ends 184, and outer edges 186 may be aligned about the axis 120 to collectively define the leading ends 182, trailing ends 184, and outer edges 186 of the compressor impeller 130, respectively.

[0024] A fluid gap 180 may be defined between the impeller 130 and the shroud surface 155. More specifically, the fluid gap 180 may be defined radially between the shroud surface 155 and the impeller 130, and axially from a front end 182 to a rear end 184 of the impeller 130. The fluid gap 180 may have a variety of shapes and sizes without departing from the scope of the present disclosure. For example, the fluid gap 180 may have a constant width (measured perpendicular to the shroud surface 155). Alternatively, the width of the fluid gap 180 may vary along its length, such as Figure 2 and Figure 3 As shown in .

[0025] like Figure 1As shown in FIG, the turbine section 113 may include a turbine wheel 131 housed within a turbine housing 188 of the housing assembly 119. The turbine housing 188 may define a turbine flow path 190 having a volute inlet passage 192 and an axial tubular outlet 194 centered about the axis 120. In some embodiments, the turbine housing 188 may be a unitary (single-piece) component manufactured via a casting operation, via an additive manufacturing process, or otherwise. The turbine housing 188 may be fixedly attached to a second axial face 196 of the base 135 of the motor housing 150 on an axial side opposite the compressor section 110. The turbine housing 188 may overlie the turbine wheel 131 with a fluid gap 198 defined therebetween.

[0026] During operation of the turbine 101, the inlet airflow (given by Figure 1 The inlet airflow 122 (indicated by arrows 122 in FIG. 1 ) may flow into the inlet 153, and the inlet airflow 122 may be compressed as it flows downstream between the compressor impeller 130 and the compressor housing 152 and into the volute passage 154. The compressed airflow (indicated by arrows 124) may exit the volute passage 154 and may be directed to the intercooler 128 and then to the fuel cell stack 104 to improve the operating efficiency of the fuel cell system 100.

[0027] Furthermore, in some embodiments, exhaust gas flow (represented by arrow 132) from the fuel cell stack 104 can be directed back to the turbine 101 and received by the volute inlet passage 192 of the turbine section 113. Thus, the exhaust gas flow 132 can drive the rotation of the turbine wheel 131 before flowing to the outlet 194. The mechanical power from the turbine section 113 can be converted into electrical power for the motor 134 to ultimately assist in the rotation of the compressor wheel 130.

[0028] Now refer to Figure 2-Figure 4 , additional features of the turbine 101 and components of the turbine 101 will now be discussed in greater detail. Due to these features, the turbine 101 can have a relatively low part count, and the tolerance stack-up of these components assembled together can be relatively low. These features will be discussed primarily with respect to the components of the compressor section 110, the motor section 112, and the bearings 121 within these sections. As will be discussed, the components of the compressor section 110, the motor section 112, and the bearings 121 can be constructed to have relatively few components that affect the radial and / or axial positioning of the compressor impeller 130 relative to the shroud surface 155. It should be understood that these features can be included for use in the turbine section 113 or another turbine for affecting the tolerance stack-up at the fluid gap 198 without departing from the scope of this disclosure.

[0029] As mentioned above and as Figure 2-Figure 4As shown, the first end 142 of the shaft 140 may include a post 149 centered about the axis 120 and secured within the sleeve 157. The post 149 projects axially from the sleeve 157 and the compressor wheel 130 is secured thereto. In some embodiments, the compressor wheel 130 may be axially secured to the post 149 between the nut 208 and the collar 200. The collar 200 may be annular and may include a front side 201 and a rear side 203 ( Figure 4 ). The front side 201 of the collar 200 may face the compressor wheel 130, and the rear side 203 may face axially in the opposite direction. Moreover, the collar 200 may include an inner diameter portion 202 having a bore that receives a neck region 255 of the sleeve 157. The inner diameter portion 202 may also include a front side recess 207 that is axially recessed to receive the hub of the compressor wheel 130. The hub of the compressor wheel 130 may be at the interface 295 ( Figure 3 ) against an opposing axial surface of the forward recess 207 at the inner diameter portion 202. The interface 295 may lie in a plane extending radially relative to the axis 120. In addition, the inner diameter portion 202 may include an aft projection 209 that projects axially away from the compressor wheel 130 and receives and secures the neck region 255 of the sleeve 157. In addition, the collar 200 may include an outer diameter portion 204 having an outer diameter groove 206 formed therein.

[0030] The embodiment of bearing 121 is also Figure 2-Figure 4 Detailed description is shown in FIG. As shown, the bearing 121 can be configured as a sliding bearing, an air bearing and / or an oil-free bearing. As shown, the bearing 121 can include a thrust bearing member 221 that primarily supports the rotating group 118 against thrust loads directed along the axis 120. The thrust bearing member 221 can include a thrust disk 220. The thrust disk 220 can be a relatively flat annular disk that is received on the shaft 140 between the rear side protrusion 209 of the collar 200 and the shoulder of the sleeve 157. In addition, the bearing 121 can include a journal bearing member 222 that primarily supports the rotating group 118 against radial loads directed radially toward the axis 120. The journal bearing member 222 can include a member having an inner diameter surface 224 ( Figure 2 ) of the journal housing 226. The journal housing 226 may be cylindrical and may surround the sleeve 157 of the shaft 140, with one end thereof being close to the thrust disc 220 and the other end being directed axially away from the first end 142 of the shaft 140.

[0031] Additionally, the journal bearing member 222 and the thrust bearing member 221 may be partially defined and / or supported by the structure of the housing assembly 119. For example, the housing assembly 119 may include a thrust cover 210 that supports a thrust plate 220. Figure 4As shown, the thrust cover 210 may be annular and may include a front side 212 axially facing the compressor wheel 130. The thrust cover 210 may also include a rear side 214 axially facing in the opposite direction. The thrust cover 210 may include an outer diameter portion 218 having a groove 219 defined therein. The thrust cover 210 may also include an inner diameter portion 216 that receives the collar 200. The inner diameter portion 216 may be sealed relative to the outer diameter portion 204 of the collar 200 by a sealing member 299 disposed within the groove 206. The thrust cover 210 may also include a rear radial flange 217. The rear radial flange 217 may project radially inward from the inner diameter portion 216 and may surround the rear protrusion 209 of the collar 200. Furthermore, the rear radial flange 217 may be axially disposed between the rear side 203 of the collar 200 and the thrust plate 220. The rear radial flange 217 can be axially spaced from the thrust disk 220 to define a gap that accommodates a thin fluid film that supports the rotation of the rotating group 118 within the housing assembly 119. The thrust cover 210 can include an inlet 211 that supplies air to the thrust disk 220. The fluid can further flow to the journal housing 226 to support the journal bearing member 222. This air supply can also cool the bearing 121 during operation.

[0032] Additionally, the housing assembly 119 may include a bearing housing 158. In some embodiments, the bearing housing 158 may be a unitary, single-piece, annular component. Figure 4 As shown, bearing housing 158 may include a support body 159 having a first axial face 160. First axial face 160 may include a first axial surface 161 that is flat and generally perpendicular to axis 120. Bearing housing 158 may also include a second axial face 164 that faces in an axial direction opposite to the axial direction of first axial face 160. Bearing housing 158 may also include an outer radial edge flange 163 that projects radially outward from support body 159. Outer radial edge flange 163 may include a first axial surface 230 and a second axial surface 232. First axial surface 230 may be flat and generally perpendicular to axis 120. Second axial surface 232 may face in an opposite direction. Outer edge surface 231 may extend between first axial surface 230 and second axial surface 232 and may have a generally constant radius. Furthermore, first axial surface 230 may be stepped axially away from first end 142 relative to first axial surface 161. Support body 159 may also include an inner diameter surface 176 that faces radially inward toward axis 120.

[0033] The bearing housing 158 may also include a bearing support portion 174 on an inner radial portion thereof for accommodating, supporting, and / or partially defining the bearing 121. The bearing support portion 174 may have a tapered and concavely shaped outer surface and may define a rearward projection 179 projecting axially away from the first end 142 of the shaft 140. The bearing support portion 174 may include a forward recess 178 located at the axial face 160. Additionally, the radius of the inner diameter surface 175 of the bearing support portion 174 (including the projection 179) may remain substantially constant along its axial length.

[0034] The thrust cover 210 can be attached to the bearing housing 158 to cover the thrust disc 220 within the recess 178. Specifically, the thrust cover 210 can be received in the bearing housing 158 with the surface 176 radially opposite the outer diameter portion 218. A sealing member 298 (e.g., an O-ring) can be received in the groove 219 to form a fluid seal between the thrust cover 210 and the opposing radial surface of the bearing housing 158. The rear side 214 of the thrust cover 210 can also fit against the opposing axial surface of the bearing housing 158 at the interface 293 ( Figure 3 ). Interface 293 may lie generally within a plane extending radially relative to axis 120. Rear side 214 and the opposing axial surface of bearing housing 158 may be polished, ground, or otherwise processed to provide them with predetermined surface characteristics (e.g., low surface roughness, high smoothness, etc.). Similarly, thrust disk 220 may be received within recess 178 of bearing housing 158, and thrust cover 210 may overlie thrust disk 220 therein. Furthermore, rear side protrusion 179 may receive journal housing 226.

[0035] Moreover, the bearing housing 158 can be partially housed within the motor cavity 129 of the motor housing 150. As shown, the stepped outer diameter surface 141 of the bearing housing 158 can be sealed against the corresponding inner diameter surface 143 of the motor housing 150 via one or more sealing members 145 (e.g., O-rings). The inner radial portion of the bearing housing 158, including the bearing support portion 174, can overlie the open axial end 137 of the base 135 and the stator 138 housed within the motor cavity 129.

[0036] Additionally, the outer radial edge flange 163 can be axially received between the compressor housing 152 and the motor housing 150, with the first axial surface 230 facing the compressor housing 152 and the second axial surface 232 facing the motor housing 150. Specifically, in some embodiments, the second axial surface 232 can abut, cover, and / or overlap an opposing axial end surface 236 of the base 135 of the motor housing 150. One or both surfaces 232, 236 can be ground or polished surfaces exhibiting low surface roughness and high smoothness (i.e., ground or polished to a predetermined surface roughness or smoothness). These mating surfaces 232, 236 can extend perpendicular to the axis 120 and extend circumferentially around the axis 120. Additionally, these surfaces 232, 236 can be secured together via one or more fasteners 238 (e.g., bolts) extending axially therebetween.

[0037] Furthermore, the compressor housing 152 can be secured to the base 135 of the motor housing 150 and can be assembled onto the bearing housing 158. Specifically, the compressor housing 152 can include an outer axial surface 240 that abuts, covers, and / or overlaps an axial end surface 236 of the base 135. The outer axial surface 240 can be a ground or polished surface exhibiting low surface roughness and high smoothness (i.e., ground or polished to a predetermined surface roughness or smoothness) for mating against the axial end surface 236. These mating surfaces 240, 236 can extend perpendicular to the axis 120 and extend circumferentially around the axis 120. Additionally, these surfaces 240, 236 can be secured together by one or more fasteners 242 (e.g., nuts and bolts) extending axially therebetween.

[0038] The axial face 108 of the compressor housing 152 may also include a recess 244 ( Figure 4 ). The recess 244 can be partially defined by the inner diameter surface 233 of the compressor housing 152. The recess 244 can be sized such that a small axial gap exists between the first axial surface 230 and the opposing axial surface of the compressor housing 152. Similarly, the recess 244 can be sized such that at least a portion of the inner diameter surface 233 abuts the outer edge surface 231 of the bearing housing 158. Both surfaces can be ground, polished, etc. to exhibit low surface roughness and high smoothness to achieve a high-tolerance radial fit therebetween. In addition, the inner lip 245 of the compressor housing 152 can accommodate the support body 159 of the bearing housing 158 and can be radially opposed to the outer diameter surface of the support body 159 with a small radial gap therebetween. The compressor housing 152 can include an inner rim notch 187 that accommodates a sealing member 189 (e.g., an O-ring), which seals against the inner surface of the notch 187, the outer edge surface 231, and the axial end surface 236 to fluidically seal the joint.

[0039] Furthermore, in this position, the first axial surface 161 of the bearing housing 158 and the diffuser surface 183 of the compressor housing 152 may face in opposite axial directions and may be separated by a distance to define a diffuser region 246 of the compressor flow path 151. The diffuser region 246 is disposed radially outward from the trailing end 184 of the compressor wheel 130 prior to the volute passage 154.

[0040] like Figure 2 and Figure 3 As shown in FIG, the axial end surface 236 of the base 135 of the motor housing 150 can be a flat, smooth surface extending perpendicular to the axis 120. The second axial surface 232 of the bearing housing 158 can also be a flat, smooth surface that extends perpendicular to the axis 120 and covers and abuts the axial end surface 236. The outer axial surface 240 of the compressor housing 152 can be a flat, smooth surface that is substantially flush with the second axial surface 232 and covers and abuts the axial end surface 236 of the motor housing 150. In this way, the base 135 of the motor housing 150 can be along an interface 291 ( Figure 3 ) mates against second axial surface 232 and axial surface 240. In some embodiments, this is a so-called "gasketless" joint because no gaskets or related components are included. Furthermore, compressor housing 152 can be radially aligned with bearing housing 158, with at least a portion of inner diameter surface 233 matching and abutting outer edge surface 231. This arrangement provides certain advantages. For example, compressor section 110 can be constructed and assembled such that the dimensions of fluid gap 180 are constructed within high tolerances. This arrangement can also make compressor section 110 very compact, highly manufacturable, and have a relatively low part count.

[0041] This arrangement may have a reduced axial and / or radial tolerance stack-up that affects fluid gap 180. In other words, there are relatively few components in this arrangement, and they are compactly arranged so that there is a reduced tolerance stack-up that affects fluid gap 180.

[0042] Specifically, if Figure 2As shown in FIG, the radial tolerance stackup affecting the fluid gap 180 may include: (a) a first radial distance 250 measured between the inner diameter surface of the recess 244 (i.e., the radial alignment surface of the compressor housing 152) and the shroud surface 155; (b) a second radial distance 252 measured between the outer edge surface 231 to the inner diameter surface 224 of the journal housing 226; (c) a second radial distance 252 measured between the inner diameter surface 224 of the journal housing 226 and the lower outer diameter surface of the shaft 140. a third radial distance 254; (d) a fourth radial distance 256 measured between the outer diameter surface of the shaft 140 and the neck region 255 of the shaft 140; (e) a fifth radial distance 258 measured between the inner diameter surface of the collar 200 at the neck region 255 and the inner diameter surface of the collar 200 at the hub of the compressor impeller 130; and (f) a sixth radial distance 260 measured between the interface at the collar 200 and the impeller 130 to the outer edge 186 of the impeller 130.

[0043] In addition, if Figure 3 As shown in , the axial tolerance accumulation affecting the fluid gap 180 may include: (a) a first axial distance 262 measured between the interface 291 and the shroud surface 155 (i.e., between the axial alignment surface 240 of the compressor housing 152 and the shroud surface 155); (b) a second axial distance 264 measured from the interface 291 to the interface 293 of the bearing housing 158 and the thrust cover 210; (c) a third axial distance 266 measured between the rear side 214 of the thrust cover 210 to the opposite side of the thrust plate 220; (d) a fourth axial distance 268 measured between the thrust plate 220 and the interface 295 of the hub of the collar 200 and the impeller 130; and (e) a fifth axial distance 270 measured from the interface 295 to the rear end 184 of the impeller 130.

[0044] Thus, the compressor section 110 is constructed with a reduced number of features that contribute to the radial and axial tolerance stack-up of the fluid clearance 180. The motor housing 150 has little to no impact on the radial and / or axial tolerance stack-up of the fluid clearance 180. The compressor housing 152 and the bearing housing 158 can both be axially aligned against the common surface 236; however, the motor housing 150 does not contribute to the radial stack-up of the fluid clearance 180. In other words, the components of the compressor section 110 can be attached together to define the fluid clearance 180 largely independent of the motor housing 150.

[0045] Thus, the compact arrangement of the compressor section 110 provides the advantages discussed above. For example, the compressor section 110 can be configured so that the size of the fluid gap 180 is maintained within tight tolerances. The number of parts can be relatively low. The compressor section 110 can also be manufactured in a repeatable manner at high volumes.

[0046] Although at least one exemplary embodiment has been presented in the above detailed description, it should be understood that there are a large number of variations. It should also be understood that one or more exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of the present disclosure in any way. On the contrary, the above detailed description will provide those skilled in the art with a convenient roadmap for implementing the exemplary embodiments of the present disclosure. It should be understood that various changes may be made to the functions and arrangements of the elements described in the exemplary embodiments without departing from the scope of the present disclosure as set forth in the appended claims.

Claims

1. A turbine comprising: motor; a housing assembly comprising a first housing member having a shroud surface, a bearing housing, and a second housing member housing the motor, wherein the bearing housing comprises a side protrusion protruding into the second housing member and a recess located at an axial face; a rotating group having a rotational axis, wherein the motor is configured to drivingly rotate the rotating group about the rotational axis, and the rotating group includes an impeller opposed to the shroud surface to define a fluid gap therebetween; an air bearing supporting the rotating group for rotation within the housing assembly about the rotational axis, wherein a journal bearing member of the air bearing is received by a side projection of the bearing housing and a thrust bearing member of the air bearing is received in the recess of the bearing housing, and wherein the thrust bearing member and the journal bearing member primarily support the rotating group against thrust loads directed along the axis and radial loads directed radially toward the axis, respectively; The first housing member has a first axial surface, and the bearing housing has a second axial surface that is substantially flush with the first axial surface; the second housing member having a third axial surface facing opposite the first and second axial surfaces along the rotational axis; the first housing member having a first radial surface and the bearing housing having a second radial surface, the first and second radial surfaces facing in opposite radial directions relative to the axis of rotation; and The first housing member and the bearing housing are attached to the second housing member, wherein the fluid gap is defined between the impeller and the shroud surface, the third axial surface has an axial alignment surface common to both the first axial surface and the second axial surface, such that the first axial surface and the second axial surface abut the common axial alignment surface of the third axial surface, and the first radial surface abuts the second radial surface.

2. The turbine according to claim 1, wherein: The first radial surface faces radially inwardly and the second radial surface faces radially outwardly.

3. The turbine according to claim 1, wherein: the second housing member defining an interior space and an end opening providing access to the interior space, the rotational axis extending through the end opening; and wherein the motor is disposed in the internal space; as well as Wherein, the bearing housing at least partially covers the end opening of the second housing component.

4. The turbine according to claim 3, wherein: The bearing housing includes a diffuser portion that cooperates with the first housing member to define a diffuser region disposed in a downstream direction of the impeller.

5. The turbine according to claim 4, wherein: The air bearing has a thrust plate and a journal housing; wherein the bearing housing comprises a recess for accommodating the thrust plate; wherein the bearing housing includes a base-side protrusion supporting the journal housing; and Also included is a thrust cover attached to the bearing housing to cover the thrust plate within the recess.

6. The turbine according to claim 5, wherein: The first housing member defines a volute passage.

7. The turbine according to claim 5, wherein: The bearing housing includes an outer radial edge flange including the second axial surface and the second radial surface, the outer radial edge flange being disposed axially between the first housing member and the second housing member. 8 . The turbomachine according to claim 7 , further comprising a sealing member that seals against the first housing member, the second housing member, and the outer radial edge flange of the bearing housing.

9. The turbine according to claim 8, wherein: The first housing member includes a recess that receives the outer radial edge flange.

10. An electric compressor device comprising: a housing assembly comprising a compressor housing having a shroud surface, a bearing housing, and a motor housing, wherein the bearing housing comprises a side protrusion protruding into the motor housing and a recess at an axial face; a rotating assembly having a compressor impeller, the compressor impeller opposing the shroud surface to define a fluid gap therebetween; an air bearing supporting the rotating group for rotation within the housing assembly about a rotational axis, at least a portion of the air bearing being housed by the bearing housing, wherein a journal bearing member of the air bearing is housed by a side projection of the bearing housing, and a thrust bearing member of the air bearing is housed in the recess of the bearing housing, and wherein the thrust bearing member and the journal bearing member primarily support the rotating group against thrust loads directed along the axis and radial loads directed radially toward the axis, respectively; and an electric motor housed within the motor housing, the electric motor being configured to drivingly rotate the rotating group within the housing assembly; The compressor housing has a first axial surface, and the bearing housing has a second axial surface that is substantially flush with the first axial surface; the motor housing having a third axial surface facing opposite the first and second axial surfaces along the rotational axis; The compressor housing has a first radial surface and the bearing housing has a second radial surface, the first and second radial surfaces facing in opposite radial directions relative to the axis of rotation; and The compressor housing and the bearing housing are attached to the motor housing, wherein the fluid gap is defined between the compressor impeller and the shroud surface, the bearing housing at least partially encloses the electric motor within the motor housing, and the third axial surface has an axial alignment surface common to both the first axial surface and the second axial surface, such that the first axial surface and the second axial surface abut the common axial alignment surface of the third axial surface, and the first radial surface abuts the second radial surface.

11. The compressor device according to claim 10, wherein: The motor housing defines an interior space and an end opening providing access to the interior space, the rotational axis extending through the end opening; wherein the electric motor is disposed in the internal space; and Wherein, the bearing housing at least partially covers the end opening of the motor housing.

12. The compressor device according to claim 11, wherein The bearing housing includes a diffuser portion that cooperates with the compressor housing to define a diffuser region that is disposed in a downstream direction of the compressor impeller.

13. The compressor device according to claim 12, wherein: The compressor housing defines a volute passage.

14. The compressor device according to claim 13, wherein The air bearing includes a thrust plate and a journal housing; wherein the bearing housing comprises a recess for accommodating the thrust plate; wherein the bearing housing includes a base-side protrusion supporting the journal housing; and Also included is a thrust cover attached to the bearing housing to cover the thrust plate within the recess.

15. The compressor device according to claim 14, wherein The bearing housing includes an outer radial edge flange including the second axial surface and the second radial surface, the outer radial edge flange being disposed axially between the compressor housing and the motor housing.

16. The compressor arrangement of claim 15, further comprising a sealing member that seals against the outer radial edge flanges of the compressor housing, the motor housing, and the bearing housing.

17. The compressor device according to claim 16, wherein The compressor housing includes a recess that receives the outer radial edge flange.

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