Patent Description:
A turbocharger can include a rotating group that includes a turbine wheel and a compressor wheel that are connected to one another by a shaft. For example, a turbine wheel can be welded or otherwise connected to a shaft to form a shaft and wheel assembly (SWA) and a compressor wheel can be fit to the free end of the shaft. An electric compressor can include one or more compressor wheels that are connected to a shaft or shafts that can be driven by an electric motor. As an example, a shaft that is attached to one or more bladed wheels may be supported by one or more bearings disposed in a bearing housing, which may form a center housing rotating assembly (CHRA). During operation of a turbocharger or an electric compressor, depending on factors such as size of various components, a shaft may be expected to rotate at speeds in excess of <NUM>,<NUM> rpm. To ensure proper rotordynamic performance, a rotating group should be well balanced and well supported over a wide range of conditions (e.g., operational, temperature, pressure, etc.). A prior art turbocharger assembly is described in <CIT>.

According to the present invention a turbocharger assembly , according to claim <NUM>, and a corresponding method, according to claim <NUM>, are disclosed.

A more complete understanding of the various methods, devices, assemblies, systems, arrangements, etc., described herein, and equivalents thereof, may be made by reference to the following detailed description when taken in conjunction with examples shown in the accompanying drawings where:.

Below, an example of a turbocharged engine system is described followed by various examples of components, assemblies, methods, etc..

Turbochargers are frequently utilized to increase output of an internal combustion engine. Referring to <FIG>, as an example, a system <NUM> can include an internal combustion engine <NUM> and a turbocharger <NUM>. As shown in <FIG>, the system <NUM> may be part of a vehicle <NUM> where the system <NUM> is disposed in an engine compartment and connected to an exhaust conduit <NUM> that directs exhaust to an exhaust outlet <NUM>, for example, located behind a passenger compartment <NUM>. In the example of <FIG>, a treatment unit <NUM> may be provided to treat exhaust (e.g., to reduce emissions via catalytic conversion of molecules, etc.).

As shown in <FIG>, the internal combustion engine <NUM> includes an engine block <NUM> housing one or more combustion chambers that operatively drive a shaft <NUM> (e.g., via pistons) as well as an intake port <NUM> that provides a flow path for air to the engine block <NUM> and an exhaust port <NUM> that provides a flow path for exhaust from the engine block <NUM>.

The turbocharger <NUM> can act to extract energy from the exhaust and to provide energy to intake air, which may be combined with fuel to form combustion gas. As shown in <FIG>, the turbocharger <NUM> includes an air inlet <NUM>, a shaft <NUM>, a compressor housing assembly <NUM> for a compressor wheel <NUM>, a turbine housing assembly <NUM> for a turbine wheel <NUM>, another housing assembly <NUM> and an exhaust outlet <NUM>. The housing assembly <NUM> may be referred to as a center housing assembly as it is disposed between the compressor housing assembly <NUM> and the turbine housing assembly <NUM>.

In <FIG>, the shaft <NUM> may be a shaft assembly that includes a variety of components (e.g., consider a shaft and wheel assembly (SWA) where the turbine wheel <NUM> is welded to the shaft <NUM>, etc.). As an example, the shaft <NUM> may be rotatably supported by a bearing system (e.g., journal bearing(s), rolling element bearing(s), etc.) disposed in the housing assembly <NUM> (e.g., in a bore defined by one or more bore walls) such that rotation of the turbine wheel <NUM> causes rotation of the compressor wheel <NUM> (e.g., as rotatably coupled by the shaft <NUM>). As an example a center housing rotating assembly (CHRA) can include the compressor wheel <NUM>, the turbine wheel <NUM>, the shaft <NUM>, the housing assembly <NUM> and various other components (e.g., a compressor side plate disposed at an axial location between the compressor wheel <NUM> and the housing assembly <NUM>).

In the example of <FIG>, a variable geometry assembly <NUM> is shown as being, in part, disposed between the housing assembly <NUM> and the housing assembly <NUM>. Such a variable geometry assembly may include vanes or other components to vary geometry of passages that lead to a turbine wheel space in the turbine housing assembly <NUM>. As an example, a variable geometry compressor assembly may be provided.

In the example of <FIG>, a wastegate valve (or simply wastegate) <NUM> is positioned proximate to an exhaust inlet of the turbine housing assembly <NUM>. The wastegate valve <NUM> can be controlled to allow at least some exhaust from the exhaust port <NUM> to bypass the turbine wheel <NUM>. Various wastegates, wastegate components, etc., may be applied to a conventional fixed nozzle turbine, a fixed-vaned nozzle turbine, a variable nozzle turbine, a twin scroll turbocharger, etc. As an example, a wastegate may be an internal wastegate (e.g., at least partially internal to a turbine housing). As an example, a wastegate may be an external wastegate (e.g., operatively coupled to a conduit in fluid communication with a turbine housing).

In the example of <FIG>, an exhaust gas recirculation (EGR) conduit <NUM> is also shown, which may be provided, optionally with one or more valves <NUM>, for example, to allow exhaust to flow to a position upstream the compressor wheel <NUM>.

<FIG> also shows an example arrangement <NUM> for flow of exhaust to an exhaust turbine housing assembly <NUM> and another example arrangement <NUM> for flow of exhaust to an exhaust turbine housing assembly <NUM>. In the arrangement <NUM>, a cylinder head <NUM> includes passages <NUM> within to direct exhaust from cylinders to the turbine housing assembly <NUM> while in the arrangement <NUM>, a manifold <NUM> provides for mounting of the turbine housing assembly <NUM>, for example, without any separate, intermediate length of exhaust piping. In the example arrangements <NUM> and <NUM>, the turbine housing assemblies <NUM> and <NUM> may be configured for use with a wastegate, variable geometry assembly, etc..

In <FIG>, an example of a controller <NUM> is shown as including one or more processors <NUM>, memory <NUM> and one or more interfaces <NUM>. Such a controller may include circuitry such as circuitry of an engine control unit (ECU). As described herein, various methods or techniques may optionally be implemented in conjunction with a controller, for example, through control logic. Control logic may depend on one or more engine operating conditions (e.g., turbo rpm, engine rpm, temperature, load, lubricant, cooling, etc.). For example, sensors may transmit information to the controller <NUM> via the one or more interfaces <NUM>. Control logic may rely on such information and, in turn, the controller <NUM> may output control signals to control engine operation. The controller <NUM> may be configured to control lubricant flow, temperature, a variable geometry assembly (e.g., variable geometry compressor or turbine), a wastegate (e.g., via an actuator), an electric motor, or one or more other components associated with an engine, a turbocharger (or turbochargers), etc. As an example, the turbocharger <NUM> may include one or more actuators and/or one or more sensors <NUM> that may be, for example, coupled to an interface or interfaces <NUM> of the controller <NUM>. As an example, the wastegate <NUM> may be controlled by a controller that includes an actuator responsive to an electrical signal, a pressure signal, etc. As an example, an actuator for a wastegate may be a mechanical actuator, for example, that may operate without a need for electrical power (e.g., consider a mechanical actuator configured to respond to a pressure signal supplied via a conduit).

<FIG> shows an example of a turbocharger system <NUM> that includes a compressor assembly <NUM>, a turbine assembly <NUM> that includes a turbine wheel <NUM> and a center housing <NUM> that is disposed between the compressor assembly <NUM> and the turbine assembly <NUM>. In the example of <FIG>, the center housing <NUM> can be an electric motor housing. In the example of <FIG>, a compressor inlet <NUM> and a compressor outlet <NUM> are shown as well as a turbine inlet <NUM> and a turbine outlet <NUM>. Further, an electric motor can be a three phase electric motor where a three phase connector <NUM> can be utilized to electrically connect the electric motor to a three phase power supply, which may be controlled via three phase electric motor control circuitry, which may be part of a computerized control system of a vehicle (e.g., an engine control unit, etc.). As an example, power may be supplied via one or more sources. As an example, a source can be a stored power source (e.g., one or more batteries) or a source can be a generator or alternator source that may be driven by an internal combustion engine (e.g., an engine that can produce exhaust gas that can be directed to the turbine inlet <NUM>).

<FIG> shows a cross-sectional view of a portion of the system <NUM> where the system <NUM> includes an electric motor assembly <NUM>, a shaft <NUM>, a compressor side bearing assembly <NUM> and a turbine side bearing assembly <NUM>. <FIG> also shows a compressor wheel <NUM> operatively coupled to the shaft <NUM>, a nut <NUM> operatively coupled to the shaft <NUM> at or proximate to a compressor end <NUM> of the shaft <NUM>, a compressor side plate <NUM> (e.g., a backplate), a turbine side plate <NUM>, the turbine wheel <NUM> that defines a turbine end <NUM> of the shaft <NUM> (e.g., as a shaft and turbine wheel assembly (SWA)), a compressor side cartridge housing <NUM>, an electric motor rotor <NUM> and an electric motor stator <NUM>.

As an example, an electric motor assembly may include a rotor that is a moving component of an electromagnetic portion that functions as an electric motor, an electric generator and/or an electric alternator. Rotation of a rotor can be due to interaction between windings and magnetic fields that produce a torque around a rotor's longitudinal, rotational axis. As an example, the system <NUM> can optionally operate as an electric generator and/or as an electric alternator. As an example, exhaust gas may be utilized to generate electricity. As an example, the electric motor assembly <NUM> may optionally be utilized to apply force to a rotor that may act to resist rotation of the rotor. As an example, such an approach may act to limit boost provided by a compressor wheel. As an example, a system may be a supercharger system that includes an electric motor and a compressor wheel.

In the example of <FIG>, electrical power may be supplied to the electric motor assembly <NUM> such that the electric motor rotor <NUM> rotates about an axis of the shaft <NUM> with respect to the electric motor stator <NUM>. In such an example, rotation of the shaft <NUM> can rotate the compressor wheel <NUM>, which may be utilized to compress air, optionally air mixed with fuel and/or exhaust.

<FIG> shows a perspective view of a portion of the system <NUM> that includes the electric motor rotor <NUM>, a compressor side bearing cartridge <NUM> and a turbine side bearing cartridge <NUM>. As shown, a sleeve <NUM> extends from a compressor side to the turbine side. The cartridge <NUM> includes opposing ends <NUM> and <NUM> where a recess <NUM> can be utilized to azimuthally locate and/or limit rotation of the cartridge <NUM> and the cartridge <NUM> includes opposing ends <NUM> and <NUM> where a recess <NUM> can be utilized to azimuthally locate and/or limit rotation of the cartridge <NUM>.

In the example of <FIG>, the recess <NUM> is open to one side whereas the recess <NUM> is closed. In such an example, the recess <NUM> may act to axially locate and/or limit axial movement of the cartridge <NUM> and, for example, one or more other components that may be operatively coupled to the cartridge <NUM>.

In the example of <FIG>, a lock nut <NUM> is threaded onto the sleeve <NUM> via mating of internal threads of the lock nut <NUM> (e.g., ID threads) and external threads of the sleeve <NUM> (e.g., OD threads). The lock nut <NUM> can be secured via one or more set screws <NUM>-<NUM> and <NUM>-<NUM>. For example, the lock nut <NUM> can be threaded onto the sleeve <NUM> to a desired position and/or a desired torque and then at least one of the set screws <NUM>-<NUM> and <NUM>-<NUM> can be rotated about its axis to contact the sleeve <NUM> with force sufficient to prevent rotation of the lock nut <NUM> with respect to the sleeve <NUM>. As an example, the lock nut <NUM> can include features that allow for interaction with a tool that can rotate the lock nut <NUM>. As an example, such features may be axial slots that may also be passages that can allow for flow of lubricant (e.g., from a bearing assembly toward a thrust collar).

<FIG> shows a cross-sectional view of a portion of the system <NUM> where various compressor side components can be seen. In <FIG>, the compressor wheel <NUM> is mounted onto the shaft <NUM> where a thrust collar <NUM> is disposed at least in part axially between the compressor wheel <NUM> and at least a portion of the sleeve <NUM>. In such an example, the compressor wheel <NUM> can be secured onto the shaft <NUM> via tightening of the nut <NUM> (e.g., a shaft nut) such that an axial load is carried by the thrust collar <NUM> and the sleeve <NUM>. As shown, the axial load is not carried by the lock nut <NUM>, which is threaded onto the sleeve <NUM>.

More particularly, in the example of <FIG>, an axial face surface <NUM> of the compressor wheel <NUM> contacts an axial face surface <NUM> of the thrust collar <NUM> and an opposing axial face surface <NUM> of the thrust collar <NUM> contacts an axial face surface <NUM> of the sleeve <NUM>. As show, an axial clearance (e.g., an axial gap) exists between the thrust collar <NUM> and an axial face surface <NUM> of the lock nut <NUM>. In the example of <FIG>, an axial clearance (e.g., an axial gap) also exists between an end <NUM> of the compressor wheel <NUM> and an end <NUM> of the sleeve <NUM>. Thus, in such an example, the compressor wheel <NUM> does not directly contact the sleeve <NUM>, rather the compressor wheel <NUM> contacts the thrust collar <NUM>, which contacts the sleeve <NUM>.

As shown, the plate <NUM> includes a bore and the thrust collar <NUM> is disposed at least in part in the bore where, for example, seal members such as piston rings, may be set in annular grooves of the thrust collar <NUM> to hinder flow of fluid from a compressor side to a center housing side of the plate <NUM> and/or vice versa. In the example of <FIG>, the compressor wheel <NUM> rotates with the shaft <NUM>, the sleeve <NUM>, the thrust collar <NUM> and the lock nut <NUM>.

<FIG> shows the cartridge <NUM> as being set in a bore <NUM> of the compressor side cartridge housing <NUM> where, for example, one or more seal members <NUM> and <NUM> (e.g., O-rings, which may be elastomeric) may be received in one or more annular grooves to form a seal between an outer surface of the cartridge <NUM> and an inner surface of the bore <NUM> of the compressor side cartridge housing <NUM>. As shown, the cartridge <NUM> includes opposing ends <NUM> and <NUM>, noting that a portion of the cartridge <NUM> extends axially inwardly from the end <NUM> (see, e.g., cross-section view of <FIG>).

<FIG> also shows a locating plate <NUM> that includes a surface <NUM> that abuts an end surface <NUM> of the compressor side cartridge housing <NUM>. As an example, the locating plate <NUM> can be bolted or otherwise secured to the compressor side cartridge housing <NUM>. In such an example, a portion of the locating plate <NUM> is received by the recess <NUM> of the cartridge <NUM> such that rotation of the cartridge <NUM> is limited (e.g., azimuthal locating). In such an example, some radial movement of the cartridge <NUM> in the bore <NUM> may occur, for example, via an extent allowable by the seal members <NUM> and <NUM> (e.g., elastomeric O-rings). As an example, such seal members may define a lubricant space between the cartridge <NUM> and the compressor side cartridge housing <NUM> such that one or more lubricant squeeze films are formed. Such films may act to damp vibrations and/or to transfer heat energy (e.g., via flow of lubricant).

As shown in <FIG>, the cartridge <NUM> includes a bore <NUM> that receives various bearing components, including components of a first bearing assembly <NUM> and components of a second bearing assembly <NUM>. As shown, the bearing assembly <NUM> includes an inner race <NUM>, an outer race <NUM> and rolling elements <NUM> disposed between the inner race <NUM> and the outer race <NUM>. As shown, the bearing assembly <NUM> includes an inner race <NUM>, an outer race <NUM> and rolling elements <NUM> disposed between the inner race <NUM> and the outer race <NUM>.

Components disposed between the first bearing assembly <NUM> and the second bearing assembly <NUM> can include an outer ring <NUM> and an inner ring <NUM> where the outer ring <NUM> includes one or more lubricant passages <NUM>. <FIG> shows an example of the outer ring <NUM> as including a lubricant passage <NUM> as an inlet lubricant passage (e.g., lubricant opening) and as including one or more lower lubricant passages (e.g., lubricant openings). The outer ring <NUM> also shows a notch that can receive a locating pin, which may limit rotation of the outer ring <NUM> about the z-axis (e.g., to assure proper alignment of lubricant features). The cartridge <NUM> can include one or more passages <NUM> that can be in fluid communication with one or more passages <NUM> of the compressor side cartridge housing <NUM> such that lubricant can be fed to the first bearing assembly <NUM> and the second bearing assembly <NUM> (e.g., via the outer ring <NUM>).

In the example of <FIG>, the lock nut <NUM> may be considered to be an inner lock nut that axially locates and/or axially loads the inner races <NUM> and <NUM> with the inner ring <NUM> therebetween. In the example of <FIG>, an outer lock nut <NUM> includes a bore <NUM> and outer threads that mate with inner threads of the bore <NUM> of the cartridge <NUM>. The outer lock nut <NUM> may be used to axially locate and/or to axially load the outer races <NUM> and <NUM> with the outer ring <NUM> therebetween. As shown, the cartridge <NUM> includes an axial face surface <NUM> within the bore <NUM> where a surface <NUM> of the outer race <NUM> can abut the axial face surface <NUM>, which may be an axial stop surface that axially locates the outer race <NUM>.

As to axial stacking, the surface <NUM> of the outer race <NUM> abuts the axial face surface <NUM> of the cartridge <NUM>, a surface <NUM> of the outer ring <NUM> abuts a surface <NUM> of the outer race <NUM>, a surface <NUM> of the outer race <NUM> abuts a surface <NUM> of the outer ring <NUM> and a surface <NUM> of the outer lock nut <NUM> abuts a surface <NUM> of the outer race <NUM>.

As an example, the lock nut <NUM> may be adjusted to an axial position, optionally according to an amount of torque, to axially locate and/or to axially load the inner races <NUM> and <NUM> and the inner ring <NUM> where the inner race <NUM> includes a surface <NUM> that abuts an axial face surface <NUM> of the sleeve <NUM> (e.g., an annular shoulder of the sleeve <NUM>).

As to axial stacking, the surface <NUM> of the inner race <NUM> abuts the axial face surface <NUM> of the sleeve <NUM>, a surface <NUM> of the inner ring <NUM> abuts a surface <NUM> of the inner race <NUM>, a surface <NUM> of the inner race <NUM> abuts a surface <NUM> of the inner ring <NUM> and the surface <NUM> of the lock nut <NUM> abuts a surface <NUM> of the inner race <NUM>.

In the example of <FIG>, the sleeve <NUM>, the lock nut <NUM>, the inner race <NUM>, the inner ring <NUM> and the inner race <NUM> rotate with the shaft <NUM> and the compressor wheel <NUM>.

In the example of <FIG>, the inner races <NUM> and <NUM> and the inner ring <NUM> can be independent of a load applied to the compressor wheel <NUM> and the thrust collar <NUM>. In such an example, where an inner race may be relatively thin or otherwise deformable under an applied load, as may be transferred from a tightened compressor wheel, the inner race is not subjected to such an applied load. Such an approach can allow for utilization of a type of bearing assembly that is independent of load applied axially to a compressor wheel (e.g., load applied by the compressor wheel <NUM> to the thrust collar <NUM> and to the shaft sleeve <NUM>).

As an example, a set of angular contact ball bearing assemblies can be configured in one or more types of configurations. For example, consider an O-type configuration, an X-type configuration and a T-type configuration. As an example, bearing assemblies may be installed in pairs and configured according to how their outer races are oriented. For example, consider a back to back configuration known as an O-type configuration, a face to face configuration known as an X-type configuration, and a series configuration known as a T-configuration or T-type configuration. In <FIG>, the bearing assemblies <NUM> and <NUM> are shown in an X-type configuration where the outer ring <NUM> is disposed axially between the outer race <NUM> and the outer race <NUM>, which have radially thicker portions that extend to the surfaces <NUM> and <NUM>, respectively. In such an example, the contact angle for the bearing assembly <NUM> is oriented from the ball <NUM> toward the surface <NUM> and the contact angle for the bearing assembly <NUM> is oriented from the ball <NUM> toward the surface <NUM>; thus, lines drawn along these two contact angles form an "X" pattern.

As an example, bearing assemblies may be oriented in an O-type configuration. For example, the bearing assemblies <NUM> and <NUM> may be oriented in a back to back configuration with the inner ring <NUM> disposed between the inner races <NUM> and <NUM>. In such an example, the radially thicker portions of the inner races <NUM> and <NUM> at surfaces <NUM> and <NUM> may bear a load, which may be applied by tightening the lock nut <NUM> on the shaft sleeve <NUM> (e.g., to a desired torque, etc.).

In the example of <FIG>, the lock nut <NUM> is adjusted to be in an axial position that allows the lock nut <NUM> to axially limit movement of the inner races <NUM> and <NUM> and the inner ring <NUM>. The lock nut <NUM> can be adjusted via rotation as threads having a thread pitch can cause rotation of the lock nut <NUM> with respect to threads having a thread pitch of the shaft sleeve <NUM> to translate the lock nut <NUM> axially. The lock nut <NUM> can hold the inner races <NUM> and <NUM> and the inner ring <NUM> to prevent axial displacement of the bearing assemblies <NUM> and <NUM>. In an X-type configuration, the outer lock nut <NUM> may be rotated via mated threads to translate the outer lock nut <NUM> axially away from the thrust collar <NUM> such that a load may be applied to the outer races <NUM> and <NUM> and the outer ring <NUM>.

As explained above, the bearing assemblies <NUM> and <NUM>, the lock nut <NUM> and the outer lock nut <NUM> may be in one or more configurations where a lock nut can axially locate and/or apply an axial load. In such examples, such an axial load can be independent of an axial load associated with tightening a compressor wheel. In the example of <FIG>, the inner races <NUM> and <NUM> and the inner ring <NUM> are secured to rotate with the sleeve <NUM> and the outer races <NUM> and <NUM> and the outer ring <NUM> are secured to the cartridge <NUM>, which remains relatively stationary with respect to the sleeve <NUM>. As an example, an assembly may include one or more springs that can be axially positioned to apply a load to a portion of a bearing assembly or portions of bearing assemblies.

<FIG> shows a cross-sectional view of a portion of the system <NUM> where various axial dimensions are indicated with respect to surfaces, particularly axial facing surfaces. Such surfaces include various paired surfaces that can be in contact and contribute to axial stack-up as to various components.

As shown in <FIG>, the thrust collar <NUM> can be defined by an axial length, the lock nut <NUM> can be defined by an axial length, the outer lock nut <NUM> can be defined by an axial length, the first bearing assembly <NUM> can be defined by an axial length or axial lengths, the outer ring <NUM> can be defined by an axial length, the inner ring <NUM> can be defined by an axial length, the second bearing assembly <NUM> can be defined by an axial length or axial lengths, etc..

As shown in <FIG>, an axial clearance exists between the compressor wheel <NUM> and the sleeve <NUM> and an axial clearance exists between the thrust collar <NUM> and the lock nut <NUM>.

As shown in <FIG>, the axial length of the lock nut <NUM> can be greater than the axial length of the outer lock nut <NUM> such that the lock nut <NUM> extends axially closer to the thrust collar <NUM> and such that an extension <NUM> of the locating plate <NUM> can extend radially inwardly to a radial position that is less than an outer radius of the outer lock nut <NUM>.

As shown in <FIG>, the locating plate <NUM> can be in contact with the compressor side cartridge housing <NUM>, for example, by being attached to the compressor side cartridge housing <NUM> (e.g., via one or more bolts, etc.). As mentioned, the locating plate <NUM> can be an anti-rotation component that can limit rotation of the cartridge <NUM> about the rotational axis of the shaft <NUM>. In such an example, the outer races <NUM> and <NUM> and the outer ring <NUM>, as well as the outer lock nut <NUM>, can be limited in their rotation via contact with an inner surface of the bore <NUM> of the cartridge <NUM> while the inner races <NUM> and <NUM> and the inner ring <NUM>, along with the lock nut <NUM>, rotate with the shaft <NUM> and the sleeve <NUM> (e.g., and the thrust collar <NUM>).

<FIG> also shows arrows as to lubricant flow through the compressor side cartridge housing <NUM>, through the cartridge <NUM> and into the passages <NUM> of the outer ring <NUM> such that the first bearing assembly <NUM> and the second bearing assembly <NUM> can be lubricated (e.g., for lubricant and heat removal). As shown in <FIG>, the bore <NUM> of the outer lock nut <NUM> defines a clearance with respect to the lock nut <NUM> such that lubricant may flow from spaces associated with the first bearing assembly <NUM> and the second bearing assembly <NUM> to a space that is in fluid communication with a drain (e.g., a lubricant outlet) that can be, for example, a cross-bore, etc. in the compressor side cartridge housing <NUM> (see, e.g., <FIG>).

<FIG> shows a cross-sectional view of a portion of the system <NUM> where various turbine side components can be seen. In <FIG>, the turbine wheel <NUM> is connected to a hub portion <NUM> of the shaft <NUM> to form a shaft and wheel assembly (SWA). As an example, the turbine wheel <NUM> can be welded to the hub portion <NUM> of the shaft <NUM>. As shown, the hub portion <NUM> of the shaft <NUM> includes annular grooves that can receive one or more seal members <NUM> such as, for example, one or more piston rings. The turbine side plate <NUM> includes a bore through which the shaft <NUM> can be inserted such that the one or more seal members <NUM> can contact a bore surface to hinder flow of fluid from a turbine side to a bearing side or vice versa. For example, lubricant flow may be hindered from the bearing side to the turbine side and exhaust flow may be hindered from the turbine side to the bearing side. As shown in <FIG>, the turbine side plate <NUM> includes an annular groove that can receive a seal member <NUM> such as, for example, an O-ring that can form a seal with a surface of the center housing <NUM>.

As shown in <FIG>, the sleeve <NUM> includes an axial face surface <NUM> that seats against an axial face surface <NUM> of the hub portion <NUM> of the shaft <NUM>. In such an example, the sleeve <NUM> is axially supported by the shaft <NUM> such that force applied to the compressor wheel <NUM>, for example, via tightening of the nut <NUM> on the shaft <NUM>, applies force to the thrust collar <NUM>, which applies force to the sleeve <NUM>.

In the example of <FIG>, inner races <NUM> and <NUM> of a first bearing assembly <NUM> and a second bearing assembly <NUM>, respectively, and an inner ring <NUM> can be independent of a load applied to the compressor wheel <NUM> and the thrust collar <NUM>, which can be transferred via the shaft sleeve <NUM> to the axial face surface <NUM> of the hub portion <NUM> of the shaft <NUM>. In such an example, where an inner race may be relatively thin or otherwise deformable under an applied load, as may be transferred from a tightened compressor wheel, the inner race is not subjected to such an applied load. Such an approach can allow for utilization of a type of bearing assembly that is independent of load applied axially to a compressor wheel (e.g., load applied by the compressor wheel <NUM> to the thrust collar <NUM> and to the shaft sleeve <NUM>).

As mentioned, a set of angular contact ball bearing assemblies can be configured in one or more types of configurations. For example, consider an O-type configuration, an X-type configuration and a T-type configuration. As mentioned, bearing assemblies may be installed in pairs and configured according to how their outer races are oriented (e.g., a back to back configuration known as an O-type configuration, a face to face configuration known as an X-type configuration, and a series configuration known as a T-configuration or T-type configuration). In <FIG>, the bearing assemblies <NUM> and <NUM> are shown in an X-type configuration where the outer ring <NUM> is disposed axially between an outer race <NUM> of the bearing assembly <NUM> and an outer race <NUM> of the bearing assembly <NUM>, which have radially thicker portions that extend to surfaces <NUM> and <NUM>, respectively. In such an example, the contact angle for the bearing assembly <NUM> is oriented from a ball <NUM> (e.g., rolling element) toward the surface <NUM> and the contact angle for the bearing assembly <NUM> is oriented from a ball <NUM> (e.g., rolling element) toward the surface <NUM>; thus, lines drawn along these two contact angles form an "X" pattern.

In the example of <FIG>, the lock nut <NUM> is adjusted to be in an axial position that allows the lock nut <NUM> to axially limit movement of the inner races <NUM> and <NUM> and the inner ring <NUM>. The lock nut <NUM> can be adjusted via rotation as threads having a thread pitch can cause rotation of the lock nut <NUM> with respect to threads having a thread pitch of the shaft sleeve <NUM> to translate the lock nut <NUM> axially. The lock nut <NUM> can hold the inner races <NUM> and <NUM> and the inner ring <NUM> to prevent axial displacement of the bearing assemblies <NUM> and <NUM>. In an X-type configuration, the outer lock nut <NUM> may be rotated via mated threads to translate the outer lock nut <NUM> axially away from the hub portion <NUM> such that a load may be applied to the outer races <NUM> and <NUM> and the outer ring <NUM>.

As explained above, the bearing assemblies <NUM> and <NUM>, the lock nut <NUM> and the outer lock nut <NUM> may be in one or more configurations where a lock nut can axially locate and/or apply an axial load. In such examples, such an axial load can be independent of an axial load associated with tightening a compressor wheel. As an example, an assembly may include one or more springs that can be axially positioned to apply a load to a portion of a bearing assembly or portions of bearing assemblies.

As shown in <FIG>, at the turbine side, the first bearing assembly <NUM> and the second bearing assembly <NUM> also include the inner races <NUM> and <NUM>, respectively, which are seated with respect to the shaft sleeve <NUM> and axially located via the lock nut <NUM>. As shown in <FIG>, an axial clearance (e.g., an axial gap) exists between the lock nut <NUM> and the hub portion <NUM> of the shaft <NUM>. Specifically, the axial clearance exists between a surface <NUM> of the lock nut <NUM> and the hub portion <NUM> of the shaft <NUM> (e.g., the surface <NUM>).

In the example of <FIG>, the lock nut <NUM> is threaded onto the sleeve <NUM> via mating of internal threads of the lock nut <NUM> (e.g., ID threads) and external threads of the sleeve <NUM> (e.g., OD threads). The lock nut <NUM> can be secured via a set screw <NUM> or set screws. For example, the lock nut <NUM> can be threaded onto the sleeve <NUM> to a desired position and/or a desired torque and then the set screw <NUM> can be rotated about its axis to contact the sleeve <NUM> with force sufficient to prevent rotation of the lock nut <NUM> with respect to the sleeve <NUM>.

As an example, a system can include one or more compressor side bearing assemblies that are loaded by a compressor side lock nut and one or more turbine side bearing assemblies that are loaded by turbine side lock nut. In such a system, the bearing assemblies can be loaded against a sleeve where inner races of the bearing assemblies rotate with the sleeve. Further, the sleeve can include a stop surface that can seat a compressor side thrust collar and, for example, a shaft can include a stop surface that can seat the sleeve. A sleeve can carry a compressor wheel load and can carry one or more independent loads as associated with one or more bearing assemblies. A compressor wheel load may be a compressive as applied to a sleeve and tensile as applied to a shaft. A bearing assembly load can be compressive as applied to a bearing assembly and can be tensile as applied to a sleeve.

<FIG> shows the cartridge <NUM> as being set in a bore <NUM> of the housing <NUM> where, for example, one or more seal members <NUM> and <NUM> (e.g., O-rings, which may be elastomeric) may be received in one or more annular grooves to form a seal between an outer surface of the cartridge <NUM> and an inner surface of the bore <NUM> of the compressor side cartridge housing <NUM>. As shown, the cartridge <NUM> includes opposing ends <NUM> and <NUM>, noting that a portion of the cartridge <NUM> extends axially inwardly from the end <NUM> (see, e.g., cross-section view of <FIG>) to an end <NUM>. In such an example, some radial movement of the cartridge <NUM> in the bore <NUM> may occur, for example, via an extent allowable by the seal members <NUM> and <NUM> (e.g., elastomeric O-rings). As an example, such seal members may define a lubricant space between the cartridge <NUM> and the housing <NUM> such that one or more lubricant squeeze films are formed. Such films may act to damp vibrations and/or to transfer heat energy (e.g., via flow of lubricant).

<FIG> also shows a locating plate <NUM> that includes a surface <NUM> that abuts an end surface <NUM> of the housing <NUM>. As an example, the locating plate <NUM> can be bolted or otherwise secured to the housing <NUM>. In such an example, an extension <NUM> of the locating plate <NUM> is received by the recess <NUM> of the cartridge <NUM> such that rotation of the cartridge <NUM> is limited azimuthally (e.g., azimuthal locating) and such that the cartridge <NUM> is limited axially (e.g., axial locating).

As shown in <FIG>, the cartridge <NUM> includes a bore <NUM> that receives various bearing components, including components of the first bearing assembly <NUM> and components of the second bearing assembly <NUM>. As shown, the bearing assembly <NUM> includes the inner race <NUM>, an outer race <NUM> and rolling elements <NUM> disposed between the inner race <NUM> and the outer race <NUM>. As shown, the bearing assembly <NUM> includes the inner race <NUM>, an outer race <NUM> and rolling elements <NUM> disposed between the inner race <NUM> and the outer race <NUM>.

Components disposed between the first bearing assembly <NUM> and the second bearing assembly <NUM> include the outer ring <NUM> and the inner ring <NUM> where the outer ring <NUM> includes one or more lubricant passages <NUM>. <FIG> shows an example of the outer ring <NUM> as including a lubricant passage <NUM> as an inlet lubricant passage (e.g., lubricant opening) and as including one or more lower lubricant passages (e.g., lubricant openings). The outer ring <NUM> also shows a notch that can receive a locating pin, which may limit rotation of the outer ring <NUM> about the z-axis. The cartridge <NUM> can include one or more passages <NUM> that can be in fluid communication with one or more passages <NUM> of the housing <NUM> such that lubricant can be fed to the first bearing assembly <NUM> and the second bearing assembly <NUM>.

In the example of <FIG>, the lock nut <NUM> may be considered to be an inner lock nut that can axially locate and/or axially load the inner races <NUM> and <NUM> with the inner ring <NUM> therebetween. In the example of <FIG>, the outer lock nut <NUM> includes a bore <NUM> and includes outer threads that mate with inner threads of the bore <NUM> of the cartridge <NUM>. The outer lock nut <NUM> may be used to axially locate and/or axially load the outer races <NUM> and <NUM> with the outer ring <NUM> therebetween. As shown, the cartridge <NUM> includes an axial face surface <NUM> within the bore <NUM> where a surface <NUM> of the outer race <NUM> can abut the axial face surface <NUM>, which may be an axial stop surface that axially locates the outer race <NUM>.

As to axial stacking, the surface <NUM> of the outer race <NUM> abuts the axial face surface <NUM> of the cartridge <NUM>, a surface <NUM> of the outer ring <NUM> abuts the surface <NUM> of the outer race <NUM>, the surface <NUM> of the outer race <NUM> abuts a surface <NUM> of the outer ring <NUM> and a surface <NUM> of the outer lock nut <NUM> abuts a surface <NUM> of the outer race <NUM>.

As mentioned, the lock nut <NUM> may be adjusted to axially locate and/or axially load the inner races <NUM> and <NUM> and the inner ring <NUM> where the inner race <NUM> includes the surface <NUM> that abuts an axial face surface <NUM> of the sleeve <NUM>.

As to axial stacking, the surface <NUM> of the inner race <NUM> abuts the axial face surface <NUM> of the sleeve <NUM>, a surface <NUM> of the inner ring <NUM> abuts the surface <NUM> of the inner race <NUM>, the surface <NUM> of the inner race <NUM> abuts a surface <NUM> of the inner ring <NUM> and the surface <NUM> of the lock nut <NUM> abuts a surface <NUM> of the inner race <NUM>.

In the example of <FIG>, the sleeve <NUM>, the lock nut <NUM>, the inner race <NUM>, the inner ring <NUM> and the inner race <NUM> rotate with the shaft <NUM> and the turbine wheel <NUM>.

In the example of <FIG>, a load applied to bearing assemblies <NUM> and <NUM> and the inner ring <NUM> and/or the outer ring <NUM> can be independent of a load applied to the sleeve <NUM> via tightening of the nut <NUM> on the shaft <NUM> to secure the compressor wheel <NUM>.

<FIG> shows a cross-sectional view of a portion of the system <NUM> where various axial dimensions are indicated with respect to surfaces, particularly axial facing surfaces.

As shown in <FIG>, the lock nut <NUM> can be defined by an axial length, the outer lock nut <NUM> can be defined by an axial length, the first bearing assembly <NUM> can be defined by an axial length or axial lengths, the outer ring <NUM> can be defined by an axial length, the inner ring <NUM> can be defined by an axial length, the second bearing assembly <NUM> can be defined by an axial length or axial lengths, etc..

As shown in <FIG>, an axial clearance exists between the hub portion <NUM> of the shaft <NUM> and the lock nut <NUM>.

As shown in <FIG>, the axial length of the lock nut <NUM> can be greater than the axial length of the outer lock nut <NUM> such that the lock nut <NUM> extends axially closer to the hub portion <NUM> of the shaft <NUM> and such that an extension <NUM> of the locating plate <NUM> can extend radially inwardly to a radial position that is less than an outer radius of the outer lock nut <NUM>.

As shown in <FIG>, the locating plate <NUM> can be in contact with the housing <NUM>, for example, by being attached to the housing <NUM> (e.g., via one or more bolts, etc.). As mentioned, the locating plate <NUM> can be an anti-rotation component that can limit rotation of the cartridge <NUM> about the rotational axis of the shaft <NUM> and/or can be an anti-translation component that can limit axial translation of the cartridge <NUM>. In such an approach, the outer races <NUM> and <NUM> and the outer ring <NUM>, as well as the outer lock nut <NUM>, can be limited in their rotation via contact with an inner surface of the bore <NUM> of the cartridge <NUM> while the inner races <NUM> and <NUM> and the inner ring <NUM>, along with the lock nut <NUM>, rotate with the shaft <NUM> and the sleeve <NUM>.

As an example, the extension <NUM> of the locating plate <NUM> may be inserted into the recess <NUM> of the cartridge <NUM> and then the cartridge <NUM> may be drawn into the bore <NUM> of the housing <NUM> and the locating plate <NUM> fixed to the housing <NUM> (e.g., via one or more bolts, etc.). At the compressor side of the system <NUM>, the locating plate <NUM> can be attached such that its extension <NUM> aligns with the recess <NUM> of the cartridge <NUM>. As shown in <FIG>, the recess <NUM> can be open at one side such that the locating plate <NUM> can be positioned with its extension <NUM> aligned with the recess <NUM> of the cartridge <NUM>. One or more bolts (e.g., or other attachment components, etc.) may be utilized to fix the locating plate <NUM> to the compressor side cartridge housing <NUM>, which can be fixed to the housing <NUM>. In such an example, the cartridge <NUM> is located at least in part by the locating plate <NUM> and the cartridge <NUM> is located at least in part by the locating plate <NUM>. As an example, the locating plate <NUM> can axially locate the cartridge <NUM> and thereby limit its axial movement in either of two opposing axial directions.

<FIG> also shows arrows as to lubricant flow through the housing <NUM>, through the cartridge <NUM> and into the passages <NUM> of the outer ring <NUM> such that the first bearing assembly <NUM> and the second bearing assembly <NUM> can be lubricated (e.g., for lubricant and heat removal). As shown in <FIG>, the bore <NUM> of the outer lock nut <NUM> defines a clearance with respect to the lock nut <NUM> such that lubricant may flow from spaces associated with the first bearing assembly <NUM> and the second bearing assembly <NUM> to a space that is in fluid communication with a drain (e.g., a lubricant outlet) that can be, for example, a cross-bore, etc. in the housing <NUM> (see, e.g., <FIG>).

<FIG> shows various components of the system <NUM> of <FIG> where a compressor side bearing assembly <NUM> is loaded onto the sleeve <NUM> by torque applied to the lock nut <NUM> and where a turbine side bearing assembly <NUM> is loaded onto the sleeve by torque applied to the lock nut <NUM>. As shown, the compressor wheel <NUM> applies a load on the sleeve <NUM> via the thrust collar <NUM>. As shown, the cartridge <NUM> is located by a locating plate <NUM> and the cartridge <NUM> is located by a locating plate <NUM>.

In the example of <FIG>, the sleeve <NUM> and bearing assemblies <NUM> and <NUM> may be considered to be a sub-assembly, along with the lock nuts <NUM> and <NUM>, which act to locate and load the bearing assemblies <NUM> and <NUM>, respectively, while the sleeve <NUM> can bear a load against the hub portion <NUM> of the shaft <NUM> as applied by the thrust collar <NUM> and the compressor wheel <NUM> being in contact with the thrust collar <NUM> where the nut <NUM> or other mechanism may be utilized to load the compressor wheel <NUM> with respect to the shaft <NUM> and the sleeve <NUM>.

In the example of <FIG>, the sleeve <NUM> can be a single piece formed of a metal or metal alloy that extends an axial length between opposing ends <NUM> and <NUM> where the end <NUM> is a free end and where the end <NUM> is in contact with the hub portion <NUM> of the shaft <NUM>. As shown, the shaft <NUM> is received by the bore <NUM> of the sleeve <NUM> where one or more pilot portions of the shaft <NUM> can be in contact with a surface of the sleeve <NUM> that defines the bore <NUM>. The bore <NUM> may include one or more diameters, one or more features, etc. According to the invention, the bore <NUM> is a stepped bore. Such a stepped bore can include one or more larger diameter portions at and/or near an end or ends and can include a smaller diameter portion over a length that is intermediate the larger diameter portions.

<FIG> shows a plan view of the thrust collar <NUM> and a cross-sectional view of the thrust collar <NUM> along a line N-N. In <FIG>, the thrust collar <NUM> is shown as including a through bore <NUM> that extends between ends <NUM> and <NUM>. The thrust collar <NUM> also includes an outer perimeter <NUM> (e.g., at a maximum diameter or maximum radius), which includes notches <NUM>-<NUM> and <NUM>-<NUM> that are disposed at about <NUM> degrees from each other in azimuthal angle about a longitudinal axis of the thrust collar <NUM> where such notches can be speed monitoring features. For example, a speed sensor <NUM> can detect the notches <NUM>-<NUM> and <NUM>-<NUM> where sensed information may be used to determine rotational speed of the shaft <NUM>. As an example, a thrust collar can include one or more notches. Where a thrust collar includes a plurality of notches, they may be located at angles that aim to balance the thrust collar where removal of material from a sacrificial portion can be utilized to balance an assembly that is a rotating assembly that includes the thrust collar.

In the example of <FIG>, the thrust collar <NUM> includes a stem portion <NUM> and a cap portion <NUM> where the cap portion <NUM> includes a sacrificial portion <NUM>, which can have, as an example, a substantially triangular cross-section, which may be an acute triangle (three angles acute, less than <NUM> degrees) or an obtuse triangle (one obtuse angle, greater than <NUM> degrees and two acute angles). As an example, a largest interior angle of a triangular shape may be a peak angle or free angle (e.g., at a free peak of a sacrificial portion).

As shown, the cap portion <NUM> also includes a sensor surface <NUM>, which is disposed at an angle to the longitudinal axis (z-axis) of the thrust collar <NUM>. As shown in <FIG>, the sacrificial portion <NUM> is formed as an integral portion of the thrust collar <NUM>. As an example, the thrust collar <NUM> may be formed at least in part by machining stock metallic material (e.g., metal or metal alloy). The sacrificial portion <NUM> may be formed and shaped in a manner that does not introduce an amount of stress that may give rise to failure of the thrust collar <NUM> as it rotates, which may be at speeds of tens of thousands revolutions per minute, which may exceed <NUM>,<NUM> rpm.

The sacrificial portion <NUM> of the thrust collar <NUM> can be a substantially continuous annular portion, which may be interrupted by continuations of the notches <NUM>-<NUM> and <NUM>-<NUM>. For example, each of the notches <NUM>-<NUM> and <NUM>-<NUM> may span an azimuthal angle of about <NUM> degrees such that the sacrificial portion <NUM> includes two spans each of about an azimuthal angle of about <NUM> degrees. As an example, a thrust collar may include a number of equally spaced sacrificial portions where material may be removed from one or more of the sacrificial portions as part of a balancing process. In such an example, removal of the material may impart or form balance cuts. As shown in <FIG>, the sacrificial portion <NUM> is disposed at or near an outermost perimeter of the thrust collar <NUM> such that a mass of material removed may impart a substantial effect on balance. The sacrificial portion <NUM> is positioned as to reduce structural effect on the stem portion <NUM>, which can bear a load associated with tightening of a compressor wheel.

In <FIG>, various axial dimensions and radial dimensions of the thrust collar <NUM> are shown. In cross-section, the thrust collar <NUM> has a J-shape (e.g., a body of revolution formed by a J-shape which may be rotated <NUM> degrees) or a hat shape (e.g., a mushroom shape).

<FIG> shows a series of increasing radii r<NUM>, r<NUM>, r<NUM>, r<NUM>, r<NUM>, r<NUM> and r<NUM>. The sacrificial portion <NUM> can be disposed between radii r<NUM> and r<NUM> (see, e.g., Δr as a base dimension of the sacrificial portion <NUM>) where a peak radius, rp, may correspond to the radius r<NUM>. As an example, the radius r<NUM> may correspond to a sensor radius of the sensor surface <NUM>. <FIG> also shows axial dimensions z<NUM>, z<NUM>, z<NUM> and z<NUM> where the sacrificial portion <NUM> can be of an axial dimension Δz, which can be equal to a difference between z<NUM> and z<NUM>. As shown in <FIG>, the stem portion <NUM> has an axial length z<NUM> and a radius r<NUM> with a bore <NUM> having a bore radius r<NUM> while the cap portion <NUM> has axial lengths of z<NUM>, z<NUM> and z<NUM> over radii from r<NUM> to r<NUM>. The notches <NUM>-<NUM> and <NUM>-<NUM> are shown of having a radial depth of about a difference between radii r<NUM> and r<NUM>.

In the example of <FIG>, the thrust collar <NUM> includes a r,Θ-plane defined in a cylindrical coordinate system (r, z, Θ) where the r,Θ-plane is at an axial position labeled zs, which demarcates the sacrificial portion <NUM> of the cap portion <NUM>. As shown, the sacrificial portion <NUM> extends in an axial direction away from the r,Θ-plane toward the end <NUM> of the thrust collar <NUM>, which is in an axial direction toward the compressor wheel <NUM> in the system <NUM>. Specifically, in the example of <FIG>, the sacrificial portion <NUM> of the thrust collar <NUM> can be positioned as practically close as possible toward the compressor end of the shaft <NUM> for the purpose of having a greater effect on balancing of a rotating group. As an example, a sacrificial portion can be positioned to avoid "confusing" a speed sensor (e.g., to avoid interference with a speed sensor's ability to sense speed).

As an example, the speed sensor <NUM> can be pointed at the sensor surface <NUM> that is substantially perpendicular to an axis of the speed sensor <NUM> (x-axis). When a metallic material is in proximity to the tip of the speed sensor <NUM>, a charge can build up. The notches <NUM>-<NUM> and <NUM>-<NUM> in the metallic material of the thrust collar <NUM> can pass the tip of the speed sensor <NUM> and release at least a portion of the built up charge and circuitry operatively coupled to the speed sensor <NUM> or part of the speed sensor <NUM> can thereby detect a rotation of the thrust collar <NUM>, for example, for calculating the speed of a rotating group. As to a balance cut, if a cut were made on the outer diameter (e.g., outer perimeter), the speed sensor <NUM> may possibly incorrectly read the cut as a notch and increase the count.

<FIG> shows a cross-sectional view of the sacrificial portion <NUM> as defined in part by the radial dimension Δr, the axial dimension Δz and the peak radius rp. Material of the sacrificial portion <NUM> may be removed at least in part to balance a rotating group where removal of such material does not interfere with the notches <NUM>-<NUM> and <NUM>-<NUM> and the speed sensor <NUM> being able to sense speed of the thrust collar <NUM> as it rotates (e.g., to count full or fractional rotations).

The sacrificial portion <NUM> can include a sufficient amount of material to allow for balancing of a rotating group of a turbocharger such as shown in the system <NUM> of <FIG>. As an example, a balancing process or balancing processes may include cutting the compressor wheel <NUM> and/or the nut <NUM> and/or the thrust collar <NUM>.

As shown in the example of <FIG>, the thrust collar <NUM> includes annular grooves <NUM>-<NUM> and <NUM>-<NUM> that can receive seal elements such as, for example, piston rings, which as mentioned may contact the backplate <NUM>, which can be attached to the compressor side cartridge housing <NUM> (see, e.g., <FIG>).

Referring to <FIG>, the thrust collar <NUM> may come into contact with lubricant that exits an annular space between the lock nut <NUM> and the cartridge <NUM> and/or the outer lock nut <NUM>. During operation, such lubricant may be driven radially outwardly along the end <NUM> of the thrust collar <NUM> and then along a surface <NUM> intermediate the end <NUM> and the sensor surface <NUM>. As the lubricant moves radially outwardly, it may be flung off of the thrust collar <NUM> and into a space defined in part by the compressor side bearing cartridge housing <NUM> and the backplate <NUM>. Such an arrangement of components may hinder migration of lubricant along the stem portion <NUM> of the thrust collar <NUM> and toward the compressor wheel <NUM>. As an example, the perimeter <NUM> of the thrust collar <NUM> may form an outermost limit for migration of lubricant where lubricant is flung radially outwardly therefrom. As shown in <FIG>, the axial dimension z<NUM> corresponds to the radius r<NUM>, which can be seen, for example, in <FIG> as (z<NUM>, r<NUM>). As seen in <FIG>, the sacrificial portion <NUM> can help reduce migration of lubricant between the backplate <NUM> and the thrust collar <NUM>.

<FIG> shows the thrust collar <NUM> as having material removed as part of a balancing process to thereby form a balance cut <NUM>. Such a balance cut can be utilized to help balance a system such as, for example, the system <NUM> of <FIG>.

As shown, the balance cut <NUM> is on the sacrificial portion <NUM> of the thrust collar <NUM>, which does not interfere with the notches <NUM>-<NUM> and <NUM>-<NUM>. <FIG> also shows the thrust collar <NUM> as including seal elements <NUM>-<NUM> and <NUM>-<NUM> seated in the annular grooves <NUM>-<NUM> and <NUM>-<NUM>. In the example of <FIG>, the compressor wheel side of the thrust collar <NUM> is on the left (shown without the backplate <NUM>) while the sleeve side of the thrust collar <NUM> is on the right (see, e.g., <FIG>). The sensor surface <NUM> is shown along with the surface <NUM> intermediate the sensor surface <NUM> and the end <NUM>.

Referring to <FIG>, the axial length of the rotating group including the compressor wheel <NUM> and the turbine wheel <NUM> is approximately four times the maximum diameter of the compressor wheel <NUM>. For example, consider a maximum compressor wheel diameter of approximately <NUM> and an end-to-end length of a rotating group of approximately <NUM>. As an example, a long rotating group may be approximately three times the maximum diameter of a compressor wheel. As an example, an electric motor may have a length of approximately <NUM>. For example, in <FIG>, the electric motor assembly <NUM> may be about <NUM> in length.

As an example, an electric motor can be rated with a power rating. For example, consider a power rating of approximately <NUM> kW to approximately <NUM> kW. As an example, the electric motor assembly <NUM> can have an electric motor rated at about <NUM> kW. As an example, the electric motor assembly <NUM> may be rated to achieve a maximum revolutions per minute of approximately <NUM>,<NUM> rpm or more, <NUM>,<NUM> rpm or more, etc. As an example, the electric motor assembly <NUM> may be rated to achieve more than <NUM>,<NUM> rpm during operation.

The overall axial length of the rotating group of the electric assist system <NUM> tends to be longer than that of a turbocharger with a center housing that is a bearing housing without an electric motor. As such, the longer axial length can make balancing, whether static or dynamic, more challenging when compared to a turbocharger without an electric motor disposed between a compressor wheel and a turbine wheel. The thrust collar <NUM> with its sacrificial portion <NUM> being positioned relatively close to the compressor wheel <NUM> can provide for balancing in addition to one or more other components that can provide for balancing of the rotating group of the system <NUM>.

As to balancing, turbo machinery parts are balanced in an effort to keep the center of gravity along a rotating axis. When balancing the subassemblies of a rotating group, many of the components tend to be substantially cylindrical. Balancing can involve removal of material, for example, through a process such as grinding. Removing material that is radially close the rotating axis tends to have relatively little effect to correct balance. As explained above, the thrust collar <NUM> includes a sacrificial portion <NUM>, which may be more than one portion, which provides a substantially triangular cross-section of material that is far enough away, radially, from the rotating axis to such that removal of material therefrom can effectuate an improvement in balance. Where a speed sensor is utilized, a sacrificial portion may be notched, which may form sacrificial portions (e.g., that span arc lengths). Where a speed sensor is utilized, a sacrificial portion or portions may be positioned to be away from a tip of the speed sensor.

As an example, a balancing process can include balancing a subassembly of a system such as the system <NUM>. In such an example, subassembly unbalance may be calculated through a physical measurement. As an example, the thrust collar <NUM> can have material removed in a specified amount per calculations at a specified angle about a rotating axis. As an example, the thrust collar <NUM> may be cut before and/or after installation as part of a rotating group. For example, an unbalance measurement tool may measure unbalance and a calculation may be made (e.g., via hand and/or by computer, circuitry, etc.) that indicates an amount of material (e.g., a mass) to be removed from a sacrificial portion of a thrust collar. The material may then be removed from the sacrificial portion of the thrust collar and the thrust collar installed on a shaft between a shaft sleeve and a compressor wheel. The assembly may be measured again as to unbalance and further adjustments made, as desired. For example, one or more additional cuts may be made to a thrust collar and/or one or more other components.

As an example, a turbocharger, whether with electric motor assist or without electric motor assist, may be mounted with respect to an internal combustion engine where a shaft of the turbocharger is substantially horizontal or where the shaft of the turbocharger deviates from being substantially horizontal. For example, consider a turbocharger that is mounted where its shaft is at an angle of about plus or minus three degrees to about plus or minus <NUM> degrees from horizontal (e.g., <NUM> degrees, which may be defined with reference to gravity), where a turbine side may be down (plus) or up (minus). In such an example, the turbocharger may be mounted with a slope where gravity can affect mechanical and/or fluid behaviors. For example, as to mechanical behaviors, balance may be affected and, as to fluid behaviors, flow of lubricant may be affected.

As an example, consider a turbocharger that has a <NUM> degree slope, with respect to the rotating axis, with the turbine side down once installed in a vehicle. As mentioned, such a slope can affect balance and lubricant behaviors. Where the turbocharger is a long turbocharger (e.g., about three times to four times compressor wheel maximum diameter or more in axial length), such as for an electric motor assist turbocharger, an ability to balance subassemblies of a rotating group can be desirable.

As an example, a turbocharger can include a turbine side collar that includes a ramped portion that can help to sling lubricant to walls that define an interior chamber of a housing such that the lubricant can better collect at a lubricant drain. Such a turbine side collar can help to reduce an amount of lubricant that may otherwise have a tendency to escape into a turbine stage, for example, for a given installation slope. As mentioned, turbo machinery parts have to be balanced to keep the center of gravity along a rotating axis. When balancing the subassemblies of a rotating group, many components are cylindrical. To help balance, material can be removed, through a process such as, for example, grinding. Removing material that is radially close to the rotating axis tends to have relatively little effect to correct balance. As an example, a turbine side collar can provide material that is far enough away, radially, from the rotating axis such that removal of a portion of such material can make a balance improvement.

As mentioned, unbalance may be calculated and/or measured, for example, via an unbalance measurement tool (e.g., a machine, etc.). As an example, a turbine side collar can have material removed in a specified amount and, for example, at a particular angle about a longitudinal axis of the collar or without regard to angle. As an example, a cut turbine side collar may be installed in an angular orientation that allows at least a portion of the unbalance to be corrected. As an example, a balancing process or balancing processes may include cutting the compressor wheel <NUM> and/or the nut <NUM> and/or the thrust collar <NUM> and/or a turbine side balance collar (see, e.g., <FIG>, <FIG> and <FIG>).

<FIG> shows an example of a balance collar <NUM> that may be utilized on a turbine side of the system <NUM>. As shown, the balance collar <NUM> includes a stepped bore <NUM> that extends between opposing ends <NUM> and <NUM> where a shoulder contour <NUM> has a flared shape that matches an exterior surface of the balance collar <NUM>. As shown, the balance collar <NUM> includes a perimeter <NUM>, which is at a maximum diameter or maximum radius of the balance collar <NUM>. As shown, the balance collar <NUM> can include a sloped annular end surface <NUM> where the slope is radially inwardly over an axial distance from the perimeter <NUM> toward the end <NUM>, which corresponds to a turbine end of the balance collar <NUM> (e.g., the end <NUM> may be a compressor end of the balance collar <NUM> or an electric motor and/or electric generator end of the balance collar <NUM>). As shown in the example of <FIG>, the sloped annular end surface <NUM> extends from the perimeter <NUM> at the radius r<NUM> to an edge at a radius re over the axial distance z<NUM>, which may define an angle φ.

In the example of <FIG>, the balance collar <NUM> includes a stem portion <NUM> and a flared portion <NUM> that includes a sacrificial portion <NUM>.

<FIG> shows various dimensions as may be given with respect to a cylindrical coordinate system, including radii r<NUM>, r<NUM>, r<NUM> and axial lengths z<NUM>, z<NUM>, z<NUM> and z<NUM>. As shown, the stepped bore <NUM> includes a radius r<NUM> over an axial length of about z<NUM>, noting that an annular chamfer can exist at an outer end of the bore <NUM> at the end <NUM>. Over an axial length z<NUM>, the stepped bore <NUM> forms an annular axial face <NUM> that can be substantially planar in an r,Θ-plane at an axial z position. The stepped bore <NUM> then has the shoulder contour <NUM> as a surface that extends to the end <NUM>.

As shown in the example of <FIG>, the stem portion <NUM> extends between the end <NUM> and the annular axial face <NUM> and may act as an axially locating portion of the balance collar <NUM>. For example, the stem portion <NUM> may be part of an axial stack up of a rotating group where the balance collar <NUM> rotates with the rotating group due to axial force applied to the stem portion <NUM>. As an example, the end <NUM> may be in contact with the shaft sleeve <NUM> and the annular axial face <NUM> may be in contact with another component such as a seal collar and/or a hub portion of a shaft (e.g., the hub portion <NUM> of the shaft <NUM>).

The sacrificial portion <NUM> can be a substantially annular ring portion that may be defined by an axial dimension z<NUM> between radii rs and r<NUM>. The sacrificial portion <NUM> may be cut to remove at least some of its material to effectuate a balance cut according to an unbalance measurement and/or unbalance calculation. As an example, a cut may be a straight cut that forms a flat, as may be defined by a chord of a circle. A chord of a circle is a straight line segment whose endpoints both lie on the circle. In such an example, the circle can be the perimeter <NUM> of the balance collar <NUM>.

<FIG> shows the balance collar <NUM> as including a balance cut <NUM>, which is shown approximately as a flat portion at the perimeter <NUM>, which may be defined at least in part by a chord of a circle. Such a balance cut can be utilized to help balance a system such as, for example, the system <NUM> of <FIG>.

<FIG> shows examples of a portion of a turbine side of a system <NUM> and a system <NUM> where each includes the shaft <NUM>, the shaft sleeve <NUM>, the turbine wheel <NUM>, the cartridge <NUM>, the bearing assemblies <NUM> and <NUM> and the outer lock nut <NUM> and where the system <NUM> includes the lock nut <NUM>.

As shown in the example system <NUM> of <FIG>, the balance collar <NUM> can be positioned with the end <NUM> against the end of the shaft sleeve <NUM> and the end of the inner race of the bearing assembly <NUM> and with the annular axial face <NUM> of the balance collar <NUM> against the surface <NUM> of the hub portion <NUM> of the shaft <NUM> where the hub portion <NUM> can include one or more annular grooves <NUM> that can seat one or more seal elements such as, for example, one or more piston rings, which may contact an inner bore surface of a housing and/or a plate (see, e.g., the plate <NUM> of the system <NUM> of <FIG>). As shown, the balance collar <NUM> is stacked with the rotating group over the axial length z<NUM>. Thus, the balance collar <NUM> may be utilized to axially locate an inner race of a bearing assembly, optionally without a lock nut such as the lock nut <NUM>.

As shown in the example system <NUM> of <FIG>, the balance collar <NUM> is positioned between the end of the shaft sleeve <NUM> and the axial face surface <NUM> of the hub portion <NUM> of the shaft <NUM> where the hub portion <NUM> can include one or more annular grooves <NUM> that can seat one or more seal elements such as, for example, one or more piston rings, which may contact an inner bore surface of a housing and/or a plate (see, e.g., the plate <NUM> of the system <NUM> of <FIG>). As shown, the balance collar <NUM> is stacked with the rotating group over the axial length z<NUM> (see, e.g., <FIG>).

As shown in the example system <NUM> of <FIG>, the hub portion <NUM> proximate to the end <NUM> of the shaft sleeve <NUM> is not in contact with the end <NUM> of the shaft sleeve <NUM>, rather, axial force applied to the shaft sleeve <NUM> (e.g., via tightening of the nut <NUM> on to the shaft <NUM>) is transferred to the hub portion <NUM> of the shaft <NUM>, which is a shaft and turbine wheel assembly (SWA).

In the example system <NUM> of <FIG>, the end <NUM> of the shaft sleeve <NUM> is in contact with the end <NUM> of the balance collar <NUM> and the annular axial face <NUM> of the balance collar <NUM> is in contact with the axial face surface <NUM> of the hub portion <NUM> of the shaft <NUM>, which is a shaft and turbine wheel assembly (SWA). As shown in the example system <NUM> of <FIG>, axial force applied to the shaft sleeve <NUM> (e.g., via tightening of the nut <NUM> on to the shaft <NUM>) is transferred to the axial face surface <NUM> of the hub portion <NUM> of the shaft <NUM>, which is shown as being attached to the turbine wheel <NUM>.

<FIG> shows arrows that approximate directions of flow of lubricant to the bearing assemblies <NUM> and <NUM> where lubricant may flow axially outwardly between an annular gap or gaps between the lock nut <NUM> and the outer lock nut <NUM> toward the balance collar <NUM>. Lubricant can then contact the outer surface of the balance collar <NUM> and migrate axially toward the turbine wheel <NUM> and radially outwardly toward the perimeter <NUM> of the balance collar <NUM>, which may include one or more balance cuts. Lubricant can be flung substantially radially outwardly away from the balance collar <NUM> as it rotates such that lubricant can more readily flow toward a lubricant exit with reduced risk of lubricant migrating toward the seal mechanism that acts to seal a turbine space with exhaust gas from a bearing space with lubricant.

As an example, a stem portion of a balance collar can bear a load. As an example, a larger diameter balance collar can have a larger effect on balance when cut. As an example, a cut can be a flat cut, which may help to avoid stress concentration when compared to, for example, a radial notch. As an example, a disc cutting tool may be utilized to cut a balance collar. As an example, a balance collar can be installed as part of a rotating group, imbalance measured, the balance collar marked, the balance collar removed, the balance collar cut and the balance collar installed at an appropriate alignment such that the balance collar as cut helps to balance the rotating group. As an example, a cutting process may cut a balance collar in situ where a tool can access the balance collar as part of a rotating group and where vacuum, a fluid stream, etc., may be utilized to help assure that debris does not interfere with the rotating group (e.g., bearing assemblies, etc.). As an example, where a lock nut is utilized, a balance collar may be shaped to allow for line of sight access to a set screw of a lock nut such that the set screw may be adjusted without having to remove the balance collar.

<FIG> and <FIG> show an example of the locating plate <NUM> with respect to the compressor side cartridge housing <NUM> along with a view of the recess <NUM> of the cartridge <NUM> and an example of the locating plate <NUM> with respect to the center housing <NUM> along with a view of the recess <NUM> of the cartridge <NUM>. As shown, the locating plate <NUM> can include one or more openings <NUM>-<NUM> and <NUM>-<NUM> and the locating plate <NUM> can include one or more openings <NUM>-<NUM> and <NUM>-<NUM>. Such opening or openings may be utilized to bolt the locating plate <NUM> or the locating plate <NUM> to a housing.

In <FIG> and <FIG>, an arrow is shown, labeled G, as representing an approximate direction of gravity (e.g., as the system <NUM> may be located and mounted in a vehicle's engine compartment). <FIG> shows a lubricant drain passage as being downwardly located with respect to gravity and <FIG> shows a lubricant drain passage as being downwardly located with respect to gravity.

The locating plate <NUM> and/or the locating plate <NUM> may be utilized in a system to provide for anti-rotation and/or axial retention. For example, such an approach may be utilized where a threaded pin in a bearing or plate on an end of a bearing cannot be used, which may be the case in some types of electric motor assist turbochargers.

As shown in <FIG>, the locating plate <NUM> includes the extension <NUM> that extends radially inwardly and the locating plate <NUM> includes the extension <NUM> that extends radially inwardly.

As shown in <FIG> and <FIG>, an extension (e.g., a tooth or key) can extend from a plate to stop (e.g., limit) rotation of a cartridge that includes one or more bearing assemblies. As mentioned, when an extension is inserted into a closed recess (e.g., a closed slot), the extension can also stop (e.g., limit) axial movement.

As an example, a plate and a recess may be dimensioned to limit rotation about an axis to a limited number of degrees and may be dimensioned to limit axial movement to a limited distance.

As an example, a plate and a recess may allow for some amount of radial movement. For example, the extension <NUM> of the locating plate <NUM> can be received by the recess <NUM> of the cartridge <NUM> where some radial movement of the cartridge <NUM> may occur, for example, within limits that may be defined by the seal elements <NUM> and <NUM>, which may be elastomeric seal elements that can deform to some extent (see also <FIG>). Such deformation may be elastic deformation such that the elastomeric seal elements can return to an original shape. As an example, a rotating group can move radially within some amount of tolerance as may be determined by various seal elements.

As an example, the extension <NUM> of the locating plate <NUM> can be received by the recess <NUM> of the cartridge <NUM> where some radial movement of the cartridge <NUM> may occur, for example, within limits that may be defined by the seal elements <NUM> and <NUM>, which may be elastomeric seal elements that can deform to some extent (see also <FIG>). Such deformation may be elastic deformation such that the elastomeric seal elements can return to an original shape. As an example, a rotating group can move radially within some amount of tolerance as may be determined by various seal elements.

As an example, the recess <NUM> of the cartridge <NUM> can include flat portions and notched corners. <FIG> shows a plan view of the recess <NUM> with the extension <NUM> received therein where the recess <NUM> is rectangular shaped in the plan view (e.g., noting that the recess <NUM> is arced about the z-axis) where the corners of the recess <NUM> are notched, for example, via drilling. In such an example, corners of the extension <NUM> may be non-contact corners in that they cannot contact a surface of the cartridge <NUM> because the corners of the recess <NUM> are notched. For example, where the cartridge <NUM> moves azimuthally about the z-axis (e.g., in an angular direction Θ of a cylindrical coordinate system about the z-axis), a flat surface of the extension <NUM> (e.g., a side edge surface) and a flat surface of the recess <NUM> (e.g., a side wall surface) can contact as the corner notches provide space to receive the corners of the extension <NUM>. Where movement occurs in an axial direction along the z-axis as to the cartridge <NUM>, a flat surface of the extension <NUM> (e.g., a face surface) and a flat surface of the recess <NUM> (e.g., a facing wall surface) can contact as the corner notches provide space to receive the corners of the extension <NUM>. As an example, the corner notches may be formed via drilling with a rotating drill bit and may be formed prior to cutting the recess <NUM> into the cartridge <NUM>. In the example of <FIG>, the corner notches may reduce stress and/or wear during operation of a system such as the system <NUM> of <FIG>.

As an example, a system can include a plate as in <FIG> and/or a plate as in <FIG>. As an example, a system can include a cartridge with a recess and without a plate with an extension. As an example, a system can include a compressor side bearing assembly in a compressor side cartridge and a turbine side bearing assembly in a turbine side cartridge. In such an example, a compressor side locating plate can be utilized to limit rotation and/or axial movement of the compressor side cartridge and/or a turbine side locating plate can be utilized to limit rotation and/or axial movement of the turbine side cartridge. In such an approach, radial movement of the compressor side cartridge and/or the turbine side cartridge may be allowed in a radial direction, which may be a direction substantially aligned with gravity. Such radial movement may be limited by one or more lubricant squeeze films and/or one or more elastomeric (e.g., spring or spring-like) members.

As an example, two plates may provide for limiting azimuthal rotation of two independent cartridges that include bores that receive ball bearing assemblies. In such an example, the two plates may work cooperatively to limit axial movement of the two independent cartridges, one plate in one axial direction and the other plate in another, opposing axial direction. As shown in <FIG>, a plate and a recess may act to limit axial movement of an assembly that includes a compressor side cartridge and a turbine side cartridge. As an example, a turbine side plate with an extension and a turbine side cartridge with a recess that receives the extension may be dimensioned to account for thermal effects (e.g., thermal expansion, etc.). As an example, as to a compressor side of a system, temperature and temperature range may be less than at a turbine side of the system, particularly where an electric motor assembly may be disposed between the turbine side and the compressor side of the system.

As an example, a system may be a fuel cell system that includes two compressor wheels that can be disposed on a common shaft, which may be a unitary shaft or a shaft assembly. Such an approach can include a motor driven by the fuel cell. As an example, one or more features described herein may be included in a fuel cell system that includes one or more compressor wheels.

As an example, a cartridge may be made of steel. For example, the cartridge <NUM> and/or the cartridge <NUM> may be made of steel. As an example, a plate or plates may be made of steel. For example, the plate <NUM> and the plate <NUM> may be made of steel. As an example, a component may be made of a metal, a metal alloy or another type of material. As an example, materials of construction may be selected based in part on operational temperature or temperatures. As an example, the sleeve <NUM> may be a unitary piece or may be a multi-piece sleeve.

The balance collar includes a stepped bore that includes an annular axial face. The axial face surface of a hub portion of a shaft seats against the annular axial face. The balance collar is loaded between an end of a component and a hub portion of a shaft. The a balance collar is loaded by an axial load between an end of a shaft sleeve and an axial face surface of a hub portion of a shaft that is disposed at least in part in a bore of the shaft sleeve.

The sacrificial portion of a balance collar is disposed over an axial length of the balance collar that does not overlap axially with a stem portion of the balance collar. For example, a stem portion of a balance collar can be axially offset from a sacrificial portion of the balance collar. Such an approach may help to decouple stress(es) experienced by the sacrificial portion from effecting the stem portion, which carries an axial load (e.g., as part of an axial stack-up chain of a rotating group).

Claim 1:
A turbocharger assembly comprising:
a shaft sleeve (<NUM>) that comprises a bore (<NUM>) that extends between a first end (<NUM>) and a second end (<NUM>);
a shaft (<NUM>) received by the bore (<NUM>) of the shaft sleeve (<NUM>) wherein the shaft (<NUM>) comprises a compressor end (<NUM>) and a turbine wheel (<NUM>) that defines a turbine end (<NUM>);
a bearing assembly (<NUM>) seated with respect to the shaft sleeve (<NUM>); and
a balance collar (<NUM>) disposed on the shaft (<NUM>) and seated axially between the second end (<NUM>) of the shaft sleeve (<NUM>) and the turbine wheel (<NUM>) wherein the balance collar (<NUM>) comprises a stepped bore (<NUM>), a stem portion (<NUM>) and a flared portion (<NUM>) that comprises a sacrificial portion (<NUM>), wherein the stepped bore (<NUM>) comprises an annular axial face (<NUM>) that extends to a shoulder contour (<NUM>) as a surface that extends to an end (<NUM>) of the flared portion (<NUM>), , wherein the sacrificial portion (<NUM>) is disposed over an axial length of the balance collar (<NUM>) that does not overlap axially with the stem portion (<NUM>) of the balance collar (<NUM>) and is disposed at a radial distance greater than an outermost radius of the stem portion (<NUM>) of the balance collar (<NUM>), characterized in that, an axial face surface (<NUM>) of a hub portion (<NUM>) of the shaft (<NUM>) seats against the annular axial face (<NUM>) of the stepped bore (<NUM>) of the balance collar (<NUM>), wherein the stem portion (<NUM>) of the balance collar (<NUM>) is loaded by an axial load between the second end (<NUM>) of the shaft sleeve (<NUM>) and the axial face surface (<NUM>) of the hub portion (<NUM>) of the shaft (<NUM>).