Media gap motor, for example for a turbocharger, and internal combustion engine

Abstract

The invention relates to a media gap motor, for example for a turbocharger (1), and to an internal combustion engine. The proposed media gap motor has a shaft (10) in or on which a rotor magnet (12) is received. The media gap motor also has a stator (9) with stator windings (22, 22') for electrically driving a rotation of the shaft (10). Furthermore, the media gap motor has a housing which delimits a flow chamber (11) arranged between the rotor (7) and the stator (9). Furthermore, the media gap motor has a compressor wheel (6) arranged in the flow chamber (11) and on the shaft (10). Furthermore, flow channels (13, 13') for guiding a partial mass flow of a medium are provided in the housing. The return flow channels (13, 13') each have an inlet (14, 14') from the flow chamber (11) and an outlet (15, 15') to the flow chamber (11). Furthermore, the return flow channels (13, 13') are guided past the stator windings (22, 22').

Description

[0001] G+L innotec GmbH

[0002] P145112PC00

[0003] Media gap motor, for example for a turbocharger, and internal combustion engine

[0004] The application relates to a media gap motor, for example for a turbocharger, according to the preamble of claim 1 and an internal combustion engine.

[0005] Internal combustion engines with turbochargers are known from the prior art. Typically, an exhaust gas flow is used to drive a turbine wheel. The turbine wheel is coupled, for example, via a shaft to a compressor wheel, which ensures the compression of fresh air supplied to a combustion chamber. Such pre-compression or turbocharging leads to increased engine power or torque compared to conventional internal combustion engines. However, these turbocharged internal combustion engines suffer from the problem of so-called turbo lag, which occurs particularly when starting and accelerating from low engine speeds, i.e., when the engine needs to quickly accelerate to higher power levels.This is because the increased air volume requirement on the air supply side can only be provided with a delay (due, among other things, to the inertia of the turbine wheel-compressor wheel system).

[0006] To reduce delay and ensure the correct amount of fresh air is supplied, the turbocharger may be designed to incorporate an electric motor with a stator and rotor. A related state of the art is described, for example, in publication WO 2008141670 Al.

[0007] Against this background, one objective of the present application is to propose an improved media-gap motor, for example for a turbocharger. In particular, one objective of the present application is to propose a media-gap motor that is compact, efficient, stable, and durable, and characterized by advantageous thermal management. Furthermore, one objective of the present application is to propose a correspondingly advantageous internal combustion engine.

[0008] These problems are solved by a media-gap motor with the features of claim 1 and by an internal combustion engine with the features of a further claim. Advantageous further developments result from the features of the dependent claims and the exemplary embodiments.

[0009] The proposed media-gap motor, for example for a turbocharger, has a shaft in or on which a rotor magnet is mounted. The media-gap motor also has a stator with stator windings for electrically driving the rotation of the shaft. Furthermore, the media-gap motor has a housing that defines a flow chamber located between the rotor and the stator. The housing can be a compressor housing. Typically, the flow chamber serves to guide a medium to be conveyed by the media-gap motor, usually a gas, particularly supplied air. Generally, a main mass flow of the medium flows through the flow chamber in a primary flow direction. The media-gap motor also has a compressor wheel located in the flow chamber and on the shaft. In some embodiments, flow channels are also provided in the housing for guiding a partial mass flow of the medium.In some embodiments, the flow channels each have an inlet from the flow chamber and an outlet to the flow chamber. Furthermore, in some embodiments, the flow channels are routed past the stator windings, for example, for heat exchange between the stator windings and the flow channels.

[0010] The proposed media-gap motor allows for an expansion of the performance map while simultaneously improving cooling. Typically, the flow channels prevent undesirable flow separation at the compressor wheel when a surge limit is reached, generating a partial mass flow that, because the flow channels are routed past the stator windings, absorbs and dissipates heat, thus cooling the stator.

[0011] In typical designs, the flow channels are return channels. These return channels can be configured for the reverse flow of a partial mass flow of the medium. This partial mass flow generally flows in the opposite direction to the main mass flow in the flow chamber. The proposed media-gap motor, particularly through recirculation, enables greater durability of the compressor wheel and, through heat exchange, improved thermal management, allowing the media-gap motor to operate across a wider operating range and thus extending its lifespan.

[0012] The application also relates to a correspondingly advantageous internal combustion engine comprising a media-gap motor designed as described above or below. Advantageously, the flow channels are integrated into the stator. It can typically be provided that the stator windings and the flow channels are arranged at a common axial position. For example, it can be provided that the flow channels are arranged between adjacent stator windings. For example, the flow channels are arranged directly between the adjacent stator windings when viewed circumferentially. Here, the stator windings and the flow channels are generally arranged at a common radial position, and in particular at different positions in the circumferential direction.In this way, the integration of the flow channels into the stator allows for a particularly robust and compact design, which also ensures particularly efficient cooling.

[0013] In typical designs, the media-gap motor has at least three, in particular at least six, and / or at most fifteen, in particular at most nine, flow channels. This allows the described advantages to be achieved with particular reliability. The flow channels are generally, and in particular uniformly, distributed around a circumference and are, for example, essentially identical in shape and size. In typical designs, a number of flow channels corresponds to a number of different bundles of coil windings. The flow channels are generally arranged between adjacent bundles of coil windings.

[0014] In typical designs, the stator has stator teeth and stator slots arranged between them. The flow channels can be arranged within the stator slots. This allows for particularly advantageous integration of the flow channels with a compact design and efficient stator cooling. In particular, each flow channel can be accommodated in its corresponding stator slot. It can be provided that no more than one, and in particular exactly one, flow channel is provided per stator slot. The flow channels are generally arranged, at least in part, between the stator teeth. It can also be advantageously provided that the stator windings are mounted on the stator teeth. This allows for a particularly compact design in which cooling by the flow channels becomes especially efficient. The stator windings can wrap around a corresponding stator tooth.The stator typically has winding heads, which can be formed, for example, by stator windings mounted on the stator teeth. By providing flow channels that bypass the winding heads, the performance area can be efficiently increased. These flow channels usually run parallel to the stator slots and / or parallel to the longitudinal sides of the stator windings, for example, with sections that are not negligible. This allows for particularly efficient cooling due to the increased surface area for heat transfer. The flow channels also typically run parallel to the main flow direction within the flow channel and / or parallel to a wall of the casing that defines the flow space, for example, with sections that are not negligible.

[0015] The flow channels, and in particular each of the flow channels, generally have a cross-sectional area that is smaller than the cross-sectional area of ​​the flow chamber at the corresponding axial position. Specifically, the cross-sectional area of ​​the flow channels, and in particular each of the flow channels, may be less than half, and in particular less than one-fifth, of the cross-sectional area of ​​the flow chamber at the corresponding axial position. The partial mass flow rate is generally smaller than the main mass flow rate and may, for example, be at most half as large. Typically, the partial mass flow rate is the sum of the mass flow rates through the flow channels.

[0016] In typical embodiments, the flow channels have a cross-sectional area that occupies at least one quarter, and in particular at least half, of the cross-sectional area of ​​an associated stator slot. In some embodiments, the cross-sectional area of ​​the stator slot can be considered the area between adjacent units formed by adjacent stator teeth and the stator windings surrounding them. It may be provided that the flow channels do not completely occupy the cross-sectional area of ​​the associated stator slot; for example, in some embodiments, the flow channels may occupy at most four-fifths of the cross-sectional area of ​​the associated stator slot. For example, the cross-sectional area of ​​the flow channel may occupy two-thirds of the cross-sectional area of ​​the associated stator slot.In this way, the available space for the stator windings and flow channels can be optimally utilized with regard to the effects achieved by the proposed media-spasting motor, by achieving, on the one hand, good electrical properties (resistance, electromotive force, etc.) and, on the other hand, the most favorable possible fluid dynamic properties (flow cross-section, flow velocity, etc.) while advantageously shifting the surge line. In some embodiments, deviations from the aforementioned relative dimensions are also possible, particularly depending on the flow capacity of the combustion engine used.

[0017] In some embodiments, the stator is provided with a yoke ring. The flow channels can run within the yoke ring. This allows for a particularly compact arrangement with efficient heat exchange. The stator teeth can extend inwards from the yoke ring. The stator teeth and the optional yoke ring can be formed from electrical steel sheets, in particular from a stator lamination stack with individual laminations. The optional yoke ring can be formed with the stator teeth as a single-piece (i.e., continuous with respect to the individual laminations) stator lamination stack. The stator teeth can have a circumferentially widened section. The widened section can, for example, be provided at an inner end of the stator tooth.This results in a particularly robust and compact design, in which the stator teeth guide the magnetic field between the flow channels towards the rotor magnet housed in the shaft. The stator teeth are typically made of a magnetically conductive material. The stator teeth may have a narrower section. This narrower section is typically located behind the wider section when viewed radially and may, for example, connect directly to the wider section. The stator windings generally wrap around the narrower section of the stator teeth. The flow channels may be arranged between two narrower sections of adjacent stator teeth. This allows for a compact and robust design. The stator windings are typically positioned between the wider sections and the yoke ring.

[0018] In preferred embodiments, at least one of the flow channels, in particular each of the flow channels, has a cross-sectional area of ​​at least 225 mm² at at least one axial position. 2 and / or a maximum of 3000 mm 2 This allows the desired flow and cooling properties to be achieved efficiently. The entire cross-sectional area is typically filled with fluid flowing through it when the surge line is reached.

[0019] In some embodiments, the flow channels are shaped such that their cross-sectional areas widen outwards, particularly radially outwards. This allows for a particularly compact design with reliable heat transfer and a sufficiently large flow cross-section. For example, the cross-sectional areas of the flow channels can be essentially wedge-shaped. Typically, the cross-sectional areas are shaped to taper inwards.

[0020] The flow channels can be arranged such that they are routed past the stator windings in such a way that the distance between the stator windings, for example, an electrically conductive section of the stator windings, and the flow channels is at most 3 mm, in particular at most 1 mm, and in particular at most 0.3 mm, at least at one point. In this way, reliable heat transfer from the stator windings to the partial mass flow can be achieved with a compact design. A heat transfer surface is generally formed between a flow channel and an adjacent stator winding, across which the heat exchange takes place. The heat transfer surface typically has an area of ​​at least 1000 mm². 2 , in particular at least 3900 mm 2A distance between the stator windings and the flow channels is maintained, which corresponds at most to the distance values ​​mentioned above. This provides a sufficiently large surface area for particularly efficient heat exchange. In some embodiments, the flow channels are provided with plastic walls. The flow channels may be separated from the stator windings by these plastic walls. This allows for a robust and easily manufactured / processed embodiment that simultaneously ensures efficient heat transfer. For example, the flow channels may be formed from a plastic potting material. This allows for efficient heat transfer with a robust design and good manufacturability. For example, the plastic material may be a thermosetting potting compound.The thermosetting material can be, for example, a filled two-component epoxy resin, particularly of thermal class H. Alternatively, the plastic material can be a thermoformable thermoplastic, such as PPS-GF30, which is filled with glass fibers. The flow channels can be manufactured as part of a motor cartridge, integrated with the cartridge. The plastic potting compound can be injection-molded, for example. The shape and size of the flow channels can be determined during manufacturing using a multi-part mold.

[0021] In some designs, the stator windings are embedded in the plastic potting compound. This allows the potting compound to potentially limit the flow channels and simultaneously protect the stator windings (e.g., from corrosion or erosion). For this purpose, the potting compound may be designed to cover the stator windings with a layer thickness of at least 1 mm to prevent the partial mass flow from attacking the stator windings. The stator teeth may also be embedded in the potting compound. In particular, the stator windings may be designed to be completely covered by the potting compound at one inner end, especially at their widened section. This results in a particularly durable design with good heat transfer properties.

[0022] It can also be designed so that the plastic potting material forms a wall within the flow chamber. Thus, in some designs, the plastic potting material can define both the flow channels and the flow chamber. This results in a robust structure with a simplified manufacturing process.

[0023] In some embodiments, the outlets of the flow channels are arranged upstream of the rotor magnet in the flow chamber with respect to the main flow direction. This allows for efficient backflow and efficient heat transfer. For example, in some embodiments, the flow channels can extend along the entire length of the stator windings in the axial direction. The outlets of the flow channels into the flow chamber can be arranged upstream of the shaft with respect to the main flow direction in the flow channel to achieve efficient cooling.

[0024] As a rule, the flow channels are separated from the flow chamber, except for their associated inlets and outlets, in particular by a section of the housing. It may be provided that the partial mass flow through the flow channels is guided parallel to a main flow direction in the flow chamber, at least section by section, and in particular over more than half the length of the flow channels.

[0025] In typical designs, the inlets of the flow channels are positioned downstream of the rotor magnet in the flow chamber with respect to the main flow direction. This further improves the flow and heat transfer characteristics. The inlets can be positioned at least partially at the same axial position as the shaft, particularly when the flow channels are designed as return channels. For example, the inlets of the flow channels can be positioned upstream of the compressor wheel or at the same level as the compressor wheel with respect to the main flow direction in the flow chamber. This ensures efficient guidance of the partial mass flow.

[0026] In particularly preferred embodiments, for example to take advantage of the distribution of flow directions caused by the compressor wheel, the inlets or outlets can be arranged in such a way that they have an axial overlap with the compressor wheel.

[0027] In preferred embodiments, the inlets of the flow channels form inlet channels. The inlet channels can be angled. The inlet channels can be angled such that the medium flowing through the inlet channels has a flow direction component that opposes the main flow direction. Additionally, the medium flowing through the inlet channels typically has a radial outward flow direction component. In this way, fluid dynamic advantages can be achieved when, for example, the backflowing medium is directed away from the flow channel, and in particular from the compressor wheel. Furthermore, the outlets of the flow channels can form outlet channels. The outlet channels can also be angled.For example, the outlet channels can be angled in such a way that the medium flowing through them has a flow direction component in the main flow direction. Additionally, the medium flowing through the outlet channels typically has a radially inward flow direction component. This design is fluidically advantageous because the medium passing through the flow channel is already guided towards the main flow direction, thus preventing turbulence. Furthermore, the inlet and / or outlet channels can be designed to form a narrow section, particularly in a cross-section along the axial direction, relative to the flow channels and the flow chamber. This minimizes the influence of the flow channels on the main mass flow within the flow channel.

[0028] In preferred embodiments, the inlets are arranged essentially in the same radial position as the outlets. For example, the inlet and outlet channels may have a radial overlap. Typically, a wall of the flow chamber is arranged between the inlets and the outlets. The wall may extend axially between the inlets and outlets. In particular, the wall between the inlets and outlets may be smooth and / or without openings. The media gap motor may be designed as a component of a turbocharger. For example, the turbocharger may have a turbine wheel. The turbine wheel may be coupled to the compressor wheel via the shaft. For example, the turbine wheel may be rotationally fixed to the compressor wheel. The turbine wheel may be mounted on the shaft. The turbine wheel may interact with an exhaust gas flow from a combustion chamber such that the exhaust gas flow drives the turbine wheel.The compressor wheel can be set up to compress the fresh air supplied to the combustion chamber.

[0029] In typical designs, the flow channels for guiding the partial mass flow and the flow chamber are arranged at a common axial position. This allows for axial overlap between the flow channels and the flow chamber. In typical designs, the flow channels are arranged in an axial region that completely overlaps the axial extent of the flow chamber. The flow channels for guiding the partial mass flow can be located radially further outward than the flow chamber. The stator can have a wall. This wall can delimit the flow chamber, for example, radially outward. The wall can separate the flow chamber from the flow channels for guiding the partial mass flow. It can be provided that a main mass flow of the medium flows through the flow chamber in a primary flow direction.In some designs, it is provided that the return flow of the partial mass flow occurs essentially in the opposite direction to the main mass flow in the flow space.

[0030] In some embodiments, the rotor magnet projects axially beyond the stator windings, particularly downstream and / or upstream with respect to a main flow direction in the flow channel. For example, the rotor magnet can extend over a larger axial area than the stator windings. This can significantly increase the power and torque density of the media-gap motor, especially if the motor incorporates the described flow channels. Even without the described flow channels, providing an axial projection of the rotor magnet can result in a significant increase in the motor's power and torque density.The rotor magnet can have a projection downstream and / or upstream over an axial extent of the stator windings of at least 2 percent, in particular at least 5 percent, of the total length of the rotor magnet.

[0031] Examples of implementation are described below with reference to the illustrations. They show

[0032] Fig. 1 shows a view of a turbocharger,

[0033] Fig. 2 shows a sectional view of a compressor housing of the turbocharger,

[0034] Fig. 3 shows a cross-sectional view of the compressor housing.

[0035] Fig. 4 shows another sectional view of the compressor housing,

[0036] Fig. 5 shows a sectional view of a compressor housing according to a further embodiment and

[0037] Fig. 6 shows a schematic view of a rotor magnet and stator windings.

[0038] Figure 1 shows a partial exploded view of an electrically modified mechanical turbocharger 1, which can be coupled to an internal combustion engine via a turbine housing 2. The present application relates to a media-gap motor, which is implemented, for example, as a component of the turbocharger 1. However, other advantageous uses for the media-gap motor are also conceivable. After combustion, the exhaust gas is collected by the exhaust manifold shown in the figure and used to drive a turbine wheel 3. The turbine wheel 3 is surrounded by the turbine housing 2 and is essentially taken from a conventional mechanical turbocharger. A bearing housing 4 and then a compressor housing 5 are connected to the turbine housing 2. A compressor wheel 6 is arranged in this compressor housing 5, which compresses air supplied through an inlet opening. The air is then fed to the combustion chamber of the internal combustion engine.In the illustrated example, the compressor wheel 6 has a left-hand extension to which an electric motor rotor 7 is attached. The rotor 7 is freely cantilevered, meaning it is not separately supported. With the turbocharger 1 fully assembled, the rotor 7 is centrally located in the intake air opening. The direction of the air intake flow is indicated in the illustration by an arrow with reference numeral 8.

[0039] A stator 9 is provided around the rotor 7. This stator is shown schematically in the figure and essentially has a hollow cylindrical shape. A rotor gap formed between the rotor 7 and the stator 9 creates a flow space for a main mass flow and simultaneously serves as an inlet air opening for the compressor wheel 6. The main mass flow flows in the compressor housing 5 essentially in a main flow direction that corresponds to the air inlet flow direction 8.

[0040] The compressor wheel 6 can (but need not) be made of a non-metallic material; for example, in an unreinforced plastic version, the influence on the electromagnetic field of the electric motor is minimized. The rotor magnet, in turn, is mounted on or in a shaft 10, on or in which the compressor wheel 6 and the turbine wheel 3 are mounted. In the present embodiment, the shaft 10 is designed such that the turbine wheel 3, compressor wheel 6, and rotor 7 are rotationally fixed to one another.

[0041] The target voltage of the electric motor is, for example, 12 V, but other voltages are also possible (e.g., 48 V to 800 V for hybrid vehicles). The electric motor can be operated both as a motor (for acceleration and to avoid turbo lag) and as a generator (for energy recuperation). When the boost pressure (in the turbine housing 2) reaches a certain target value, additional electrical energy is generated using a regenerative inverter. The electric motor of the turbocharger 1 is connected to an electrical energy storage system for drawing electrical energy during motor operation of the turbocharger 1 and for feeding electrical energy into the system during generator operation of the turbocharger 1. For efficient control of the drive system, etc.The turbocharger 1 includes control electronics for determining the speed of turbine wheel 3 or compressor wheel 6, actual values ​​of turbine housing-side and compressor housing-side pressure conditions, and other values ​​relevant to the torque of the internal combustion engine.

[0042] Figure 2 shows a sectional view through the compressor housing 5 of the turbocharger 1. Recurring features are identified by the same reference numerals in this and the following figure. The rotor 7 is arranged centrally in the flow chamber 11, which is bounded by the stator. A main mass flow is directed in the flow chamber 11 towards the compressor wheel 6, which is also located in the flow chamber 11 (to the left in the figure). The rotor 7 has a rotor magnet 12, which is surrounded by a reinforcement 25. The compressor wheel 6 is non-rotatably connected to the shaft 10. The reinforcement 25 and the rotor 7 can be considered part of the shaft 10, which need not necessarily be a single piece. The stator 9 is integrated into the compressor housing 5. Flow channels 13, 13' are also provided in the compressor housing 5. In some embodiments, the flow channels are designed as return channels 13, 13'.These channels allow a partial mass flow to be directed backwards against the main flow direction. The flow channels 13, 13' pass through the stator 9 and run essentially in an axial direction. The flow channels 13, 13' are routed past stator windings of the stator 9, so that the stator windings are in heat-transferring contact with the flow channels 13, 13'. The flow channels 13, 13' extend over the entire axial length of the stator windings.

[0043] The flow channels 13, 13' are each fluidically connected to the flow chamber 11 via an inlet 14, 14' and an outlet 15, 15'. The inlets 14, 14' are located at the level of the compressor wheel 6, thus having an axial overlap with the compressor wheel 6. The outlets 15, 15' are located upstream of the inlets 14, 14' (i.e., to the right of them in the figure) with respect to the main flow direction in the flow chamber 11. Furthermore, the outlets 15, 15' are located upstream of the rotor magnet 12 and an upstream end of the shaft 10, which may, for example, be formed by a cap of the reinforcement 25. The inlets 14, 14' also form narrowed inlet channels 16, 16' through which the, for example, backflowing medium from the flow chamber 11 flows radially outwards and at the same time with an axial component against the main flow direction (i.e., in the figure with a component to the right).Furthermore, the outlets 15, 15' form narrowed outlet channels 17, 17' through which the backflowing medium flows back into the flow chamber 11. The outlet channels 17, 17' are shaped such that the medium flows radially inwards within them and simultaneously with a component in the main flow direction (i.e., with a component to the left in the figure).

[0044] Figure 3 shows another sectional view illustrating the structure of the stator 9 in more detail. A total of six flow channels, two of which are designated 13 and 13', are evenly distributed around the circumference. The flow channels 13 and 13' are identical in shape and size and are wedge-shaped, such that their cross-sections taper continuously radially inwards. The stator 9 also has a yoke ring 18, from which six stator teeth, two of which are designated 19 and 19', extend inwards and are evenly distributed around the circumference. The yoke ring 18 and the stator teeth 19 and 19' are formed together from a single stator lamination stack. The stator teeth 19, 19' are elongated in the axial direction and each has a narrower section 20, 20' with respect to a circumferential direction and a wider section 21, 21' with respect to the circumferential direction.The widened section 21, 21' forms a radially inner end of the stator tooth 19, 19' and the narrower section 20, 20' is arranged between the widened section 21, 21' and the yoke ring 18.

[0045] The stator 9 also includes stator windings, two of which are designated by reference numerals 22 and 22'. The stator windings 22, 22' are mounted on and encircle the narrower sections 20, 20' of the stator teeth 19, 19'. The stator windings 22, 22' are embedded in the recesses formed by the narrower sections 20, 20' of the stator teeth 19, 19'. Stator grooves are formed between the stator teeth 19, 19', including the surrounding stator windings 22, 22', in which the flow channels 13, 13' are arranged. The flow channels 13, 13' fill more than half of the cross-sectional area of ​​the associated stator groove. The flow channels 13, 13' are arranged between adjacent stator teeth 19, 19', specifically between their narrower sections 20, 20'. Furthermore, the flow channels 13, 13' are arranged between adjacent stator windings 22, 22'.This means that the stator windings 22, 22' and the flow channels 13, 13' are arranged at a common radial position, i.e. at least in some areas at the same distance from the axis of rotation of the rotor 7.

[0046] The stator teeth 19, 19' and the stator windings 22, 22' are jointly embedded in a one-piece, non-jointed plastic potting material 23. The plastic potting material 23 completely covers the radially inner ends of the stator teeth 19, 19'. The plastic potting material 23 also forms a cylindrical inner wall 24 of the stator 9, which delimits the flow chamber 11. The flow channels 13, 13' are also formed from the plastic potting material 23. Between each of the stator windings 22, 22' and the adjacent flow channel 13, 13', only the plastic potting material 23 is present, forming a thin heat-transferring layer that may also prevent corrosion of the stator windings 22, 22'.

[0047] Figure 4 illustrates possible flow paths (see arrows) of the partial mass flow. While the main flow direction in the flow chamber 11 runs to the left in the illustration, the partial mass flow in the flow channels 13, 13', which in this embodiment are designed as return flow channels, is guided in essentially the opposite direction.

[0048] Figure 5 illustrates a further embodiment that incorporates some or all of the features described above in relation to the other embodiment in a corresponding manner. However, in the further embodiment according to Figure 5, the partial mass flow in the flow channels 13, 13' is guided essentially in the main flow direction (i.e., to the left in the illustration). For this purpose, the inlets 14, 14' are designed such that the partial mass flow can flow axially from the flow chamber 11 into the flow channels 13, 13'. In this embodiment, the inlets 14, 14' are arranged at a radially more outward position than the outlets 15, 15'.

[0049] Figure 6 illustrates that, for a further increase in the power density of the media-gap motor described above, the rotor magnet 12 extends beyond an axial area on both a downstream and an upstream side, over which the stator windings 22 extend. The rotor magnet 12 has an axial projection on both sides relative to the stator windings 22. Field line profiles are also shown.

[0050] Only features of the various embodiments disclosed in the exemplary embodiments can be combined and claimed individually.

Claims

G+L innotec GmbH P145112PC00 Patent claims 1. Media gap motor, for example for a turbocharger (1), with a shaft (10) in or on which a rotor magnet (12) is mounted, a stator (9) with stator windings (22, 22') for electrically driving a rotation of the shaft (10), a housing that defines a flow space (11) arranged between the rotor and the stator (9), and a compressor wheel (6) arranged in the flow chamber (11) and on the shaft (10), characterized by the fact that The housing has flow channels (13, 13') for guiding a partial mass flow of a medium, wherein the flow channels (13, 13') each have an inlet (14, 14') from the flow chamber (11) and an outlet (15, 15') to the flow chamber (11), wherein the flow channels (13, 13') are routed past the stator windings (22, 22') for heat exchange between the stator windings (22, 22') and the flow channels (13, 13').

2. Media gap motor according to claim 1, characterized in that the flow channels (13, 13') for guiding the partial mass flow and the flow chamber (11) are arranged at a common axial position.

3. Media gap motor according to one of claims 1 or 2, characterized in that the flow channels (13, 13') for guiding the partial mass flow are arranged radially further outwards than the flow space (11).

4. Media gap motor according to one of claims 1 to 3, characterized in that the stator (9) has a wall (24) that delimits the flow space (11).

5. Media gap motor according to claim 4, characterized in that the wall (24) separates the flow space (11) from the flow channels (13, 13') for guiding the partial mass flow.

6. Media gap motor according to one of claims 1 to 5, characterized in that a main mass flow of the medium flows through the flow space (11) in a main flow direction.

7. Media gap motor according to one of claims 1 to 6, characterized in that the flow channels are return flow channels (13, 13') which are equipped for a return flow of the partial mass flow of the medium.

8. Media gap motor according to claim 7, characterized in that a main mass flow of the medium flows through the flow space (11) in a main flow direction and the return flow of the partial mass flow is substantially opposite to the main mass flow in the flow space (11).

9. Media gap motor according to one of claims 1 to 8, characterized in that the flow channels (13, 13') are each arranged between adjacent stator windings (22, 22').

10. Media gap motor according to one of claims 1 to 9, characterized in that the stator (9) has stator teeth (19, 19') and stator grooves arranged between them, wherein the flow channels (13, 13') are arranged in the stator grooves.

11. Media gap motor according to claim 10, characterized in that the flow channels (13, 13') have a cross-sectional area that occupies at least one quarter of a cross-sectional area of ​​an associated stator slot.

12. Media gap motor according to any one of claims 1 to 11, characterized in that the stator (9) has a yoke ring (18), wherein the flow channels (13, 13') run within the yoke ring (18).

13. Media gap motor according to one of claims 1 to 12, characterized in that the flow channels (13, 13') are shaped such that cross-sectional areas of the flow channels (13, 13') are widened outwards.

14. Media gap motor according to one of claims 1 to 13, characterized in that the flow channels (13, 13') are routed past the stator windings (22, 22') in such a way that the distance between the stator windings (22, 22') and the flow channels (13, 13') is at most 3 mm at at least one point.

15. Media gap motor according to one of claims 1 to 14, characterized in that the flow channels (13, 13') are formed from a plastic potting material (23).

16. Media gap motor according to one of claims 1 to 15, characterized in that the outlets (15, 15') of the flow channels (13, 13') are arranged upstream of the rotor magnet (12) with respect to a main flow direction in the flow space (11).

17. Media gap motor according to one of claims 1 to 16, characterized in that the inlets (14, 14') of the flow channels (13, 13') are arranged downstream of the rotor magnet (12) with respect to a main flow direction in the flow space (11).

18. Media gap motor according to one of claims 1 to 17, characterized in that the inlets (14, 14') of the flow channels (13, 13') are arranged upstream of the compressor wheel (6) or at the level of the compressor wheel (6) with respect to a main flow direction in the flow space (11).

19. Media gap motor according to one of claims 1 to 18, characterized in that the inlets (14, 14') of the flow channels (13, 13') form inlet channels (16, 16') which are shaped in such a way that the medium flowing through the inlet channels (16, 16') has a flow direction component which is opposite to the main flow direction.

20. Media gap motor according to one of claims 1 to 19, characterized in that the outlets (15, 15') of the flow channels (13, 13') form outlet channels (17, 17') which are shaped in such a way that the medium flowing through the outlet channels (17, 17') has a flow direction component in the main flow direction.

21. Media gap motor according to one of claims 1 to 20, characterized in that the rotor magnet (12) extends over a larger axial area than the stator windings (22, 22').

22. Media gap motor according to one of claims 1 to 21, characterized in that the rotor magnet (12) projects in an axial direction in relation to a main flow direction in the flow channel (11) downstream and / or upstream over an axial area over which the stator windings (22, 22') extend.

23. Internal combustion engine comprising a media gap engine according to any of the preceding claims.

Images