DE102020214336A1 - Media splitting machine, turbocharger with such a media splitting machine and power generation device with such a turbocharger - Google Patents

Abstract

The invention relates to an electrical media splitting machine (7) for a turbocharger (3), in particular an exhaust gas turbocharger of a power generation device (1), with a housing (9), a rotor (11) being rotatably mounted in the housing (9), and with - a stator (13) fixed to the housing, which has a drive winding (15) for generating a drive magnetic field, wherein between the rotor (11) and the stator (13) there is a media gap (17 ) is formed, which is interspersed with a media flow of a medium during operation of the media splitting machine (7), wherein- the stator (13) has stator laminations (19), wherein- a plurality of the stator laminations (19) is embodied as guide plates (21), the baffle plates (21) protruding radially inwards into the media gap (17) at least in regions beyond a peripheral wall (23) of the media gap (17).

Description

The invention relates to an electric media splitting machine for a turbocharger, a turbocharger with such a media splitting machine and a power generation device with such a turbocharger.

An electrical media splitting machine has a housing in which a rotor is rotatably mounted. It also has a stator fixed to the housing, which has an in particular multi-phase drive winding for generating an in particular multi-pole drive magnetic field. Between the rotor and the stator there is a media gap which encompasses an axis of rotation of the rotor in a ring shape and which gives the media splitting machine its name, and through which a media flow of a medium passes during operation of the media splitting machine. On the one hand, this allows the media splitting machine to be used in a particularly efficient and simple manner in connection with the conveyance and/or compression of a medium, for example to drive or support a media compressor, with the media splitting machine being advantageously used on the other hand by the medium passing through the media gap is cooled.

Such an electrical media splitting machine can in particular be combined with a turbocharger, in particular an exhaust gas turbocharger of a power generation device, in particular an internal combustion engine or a fuel cell. The electric media splitting machine is then used in particular to support the turbocharger, for example in order to be able to adjust the compression output of the turbocharger largely independently of a current exhaust gas flow of a power generation device, in which case a so-called turbo lag can be overcome by electric motors or a lack of exhaust gas energy can be compensated for. At certain operating points, the media splitting machine can also be operated as a generator, so that flow energy can be recuperated as electrical energy by the turbocharger, for example.

Out of DE 20 2015 101 916 U1 discloses an electrical machine in connection with a turbocharger, in which a rotor arranged on a common shaft with a compressor wheel of the turbocharger carries an impeller acting as an axial compressor, with permanent magnets of the rotor being arranged radially on the outside on a circumference of the impeller and with a stator fixed to the housing work together. In the direction of flow behind the impeller and axially also behind the stator fixed to the housing, a guide device fixed to the housing is arranged in order to influence the flow towards the compressor wheel. This embodiment can be improved with regard to the magnetic flux, the compactness of the arrangement and the integration of the various components.

The invention is based on the object of creating a media splitting machine, a turbocharger with such a media splitting machine and a power generation device with such a turbocharger, the disadvantages mentioned being at least partially eliminated, preferably avoided.

The object is achieved by providing the present technical teaching, in particular the teaching of the independent claims and the embodiments disclosed in the dependent claims and the description.

The object is achieved in particular by further developing an electrical media gap machine in such a way that the stator has stator laminations, with at least some of the stator laminations being designed as guide plates, with the guide plates extending radially inwards at least in some areas beyond a peripheral wall of the media gap - i.e. towards the rotor - protrude into the media gap. In this way, the magnetic field of the stator is preferably advantageously configured, in particular guided and/or reinforced, with regard to the efficiency of the electric media splitting machine. In addition, an additional use for the stator is preferably advantageously created in that it acts at the same time as a guide device, in particular as a pre-guide device, for the media flow, so that the electrical media splitting machine has a high level of functional integration. Correspondingly, the structure of the media splitting machine can also be designed to be compact.

The stator laminations are preferably designed as iron cores of coils of the drive winding.

The stator preferably has a large number of stator laminations, the plurality of stator laminations, which are designed as guide plates, being smaller than the large number. In particular, therefore, a minority or subset of the stator laminations is designed as guide plates. In a preferred embodiment, however, it is also possible for each stator lamination to be in the form of a baffle, in which case the number of baffles is equal to the number of stator lamination. Stator laminations that are not designed as guide plates preferably do not protrude beyond the peripheral wall of the media gap and do not project radially inwards into it. In particular, such stator laminations themselves preferably form part of the peripheral wall of the media gap or are radial arranged within the peripheral wall or on the peripheral wall of the media gap.

The rotor preferably has at least one permanent magnet, preferably a plurality of permanent magnets, which interact with the drive magnetic field generated by the drive winding during operation of the media splitting machine in order to set the rotor in rotation.

According to a development of the invention, it is provided that the guide plates extend in the radial direction up to the rotor. This leads to a particularly advantageous configuration of the magnetic field, in particular of the magnetic flux, in which case the efficiency of the media splitting machine in particular can be high. Preferably, the shortest distance of a guide plate, preferably all guide plates, from an outer peripheral surface of the rotor is at most 3% of a diameter of the rotor, i.e. the rotor diameter, preferably from at least 0.5 mm to at most 2 mm, preferably from at least 1 mm to at most 2mm

According to a development of the invention, it is provided that the rotor carries a plurality of rotor blades, which are arranged on the rotor in a rotationally fixed manner offset in the axial direction relative to the guide plates. In this way, the function of an axial compressor is preferably additionally provided for the media splitting machine, with a particularly compact arrangement of the axial compressor and the inflow vane and a particularly integrated design being able to be realized for the media splitting machine proposed here. In addition, a pressure ratio can advantageously preferably be increased for a turbocharger arranged downstream of the electric media splitting machine. In particular, two-stage charging is provided in combination with the turbocharger.

The axial direction is understood to mean, in particular, a direction that extends parallel to the axis of rotation, preferably coinciding with the axis of rotation. A radial direction or radial direction is perpendicular to the axis of rotation, a circumferential direction encompasses the axis of rotation concentrically.

A distance, measured in the axial direction, between the rotor blades and the guide plates is preferably at least 1 mm to at most 20% of a rotor blade height of the rotor blades, measured at the entry of the media flow.

According to a development of the invention, it is provided that the moving blades—with reference to the media flow—are arranged upstream of the guide plates in the media gap. In this way in particular, a very efficient configuration of the axial compressor on the one hand and of the inlet guide apparatus on the other hand can be achieved.

According to a development of the invention, it is provided that the guide plates are shaped and/or adjusted in such a way that the media flow passing through the media gap undergoes a twist change through the guide plates during operation of the media splitting machine, with preferably a twist of the media flow, i.e. a rotational movement component or a Angular momentum is changed, in particular increased or reduced. This includes that a twist is created in the first place - that is, increased starting from zero - or that a twist is destroyed - that is, reduced to zero. The change in swirl can preferably improve the inflow behavior for a part downstream of the media splitting machine in the direction of flow, for example a turbocharger, with a surge limit being advantageously shifted and/or a swirl induced by an axial compressor stage being advantageously reduced, particularly in the case of a turbocharger.

The fact that the baffles are shaped in such a way that the media flow passing through the media gap experiences the twist change means in particular that they have a suitable external shape, for example the shape of blades or the like, so that the flow flowing past the baffles is imparted with a twist change.

The fact that the baffles are set in such a way that the flow of media undergoes the change in twist means in particular that they are arranged at a suitable angle to the flow of media, in particular at a suitable angle to the axial direction, so that the change in twist is imparted to the flow of media as it flows around the baffles .

It is also possible for the guide plates to be shaped and positioned in such a way that the change in twist is imparted to the media flow passing through the media gap.

According to a preferred embodiment, the guide plates are shaped or positioned in such a way that they impart a co-swirl to the media flow with respect to the direction of rotation of the compressor wheel, ie an oncoming flow in the direction of rotation of the compressor wheel. This advantageously shifts the compressor map to lower volume flows.

According to another preferred embodiment, the guide plates are shaped or positioned in such a way that they impart a counter-swirl to the media flow, ie an oncoming flow counter to the direction of rotation of the compressor wheel. This advantageously shifts the compressor map to higher volume flows.

According to a development of the invention, it is provided that the stator is integrated into the housing. In particular, the drive winding of the stator is preferably integrated into the housing. In this way, the integration of the electrical media splitting machine proposed here can be further increased, and the media splitting machine is designed to be particularly compact.

According to a further development of the invention, it is provided that a flow channel is formed in the housing, which is set up to guide a recirculation flow for the turbocharger along a recirculation flow direction counter to a media flow direction of the media flow in the media gap.

Accordingly, the flow duct advantageously allows a recirculation flow to be guided, ie it acts as a recirculation duct, which is in particular a map-stabilizing measure for the turbocharger with which the electric media splitting machine interacts. The flow channel is in particular arranged and/or designed in such a way that it can receive the recirculation flow on the compressor side, guide it back against the media flow direction and feed it back into the media flow, preferably into the media gap, at a suitable point upstream of the compressor.

A media flow direction is to be understood in particular as a main flow direction of the medium in the media gap. Irrespective of any local deviations from the main flow direction or a swirl superimposed on the main flow direction, the medium in the media gap flows at least essentially in the axial direction, ie in the direction of the axis of rotation. The recirculation flow direction is opposite to the media flow direction; the part of the medium recirculated through the flow channel thus flows at least in regions, preferably essentially, counter to the main flow direction of the medium flowing in the media gap.

In a preferred embodiment, the flow channel is formed in the stator. The stator is then advantageously additionally cooled by the recirculation flow, as a result of which the heat dissipation in the region of the stator is improved. This also enables a simpler configuration of the housing, in particular since the heat dissipation of the stator has to be ensured to a lesser extent via the housing. The flow channel formed in the stator can be manufactured simply and inexpensively and does not impair the efficiency of the compressor.

According to a development of the invention, it is provided that the flow channel passes through the drive winding of the stator. A flow guided in the flow channel then advantageously contributes in particular to the cooling of the drive winding. In a preferred embodiment, the recirculation channel can be produced at the same time as the manufacture of the stator, in particular during the manufacture of the drive winding.

According to a preferred embodiment, it is provided that the flow channel at one end - in particular upstream of the rotor, or in the area of a front end of the rotor against which the flow occurs, or in an area of the rotor - opens into the media flow flowing through the media gap or into the media gap, whereby it opens at the other end downstream of the rotor in a flow area behind the media gap, that is to say downstream of the media gap, in particular in an area of a compressor wheel of a turbocharger equipped with the media gap machine.

In order to improve the flow against the rotor, a flow cap can be assigned to it offset along the axis of rotation in the direction of flow, which is then arranged in the axial direction upstream of the rotor, ie in front of the rotor. If this inflow cap is not connected in a rotationally fixed manner to the rotor itself, it is connected in a rotationally fixed manner to the housing via a plurality of webs.

According to a preferred embodiment, it is provided that the webs, via which the inflow cap is connected to the housing in a rotationally fixed manner, are shaped or positioned in such a way that the media flow passing through the media gap is imparted by the webs during operation of the media splitting machine a twist change. As a result, on the one hand, the inflow behavior for a part downstream of the media splitting machine in the direction of flow, for example a turbocharger, can be additionally improved, with a surge limit being able to be advantageously shifted further, particularly in the case of a turbocharger; on the other hand, to further improve the flow behavior of the medium in the media gap, the webs can be used in a simple and cost-effective manner, which webs hold the inflow cap and in particular connect it to the housing in a torque-proof manner. These are therefore not only strö shaped, in particular to advantageously reduce their flow resistance, but they fulfill a function with regard to the flow properties of the medium in the media gap by communicating the corresponding twist change to the medium, i.e. the media flow, when they are in operation of the media gap machine from the Medium flows around. At the same time, the inflow cap directs the inflowing medium past the rotating rotor, so that the medium flow is also favorable in this area.

The webs serve in particular as an additional inlet guide apparatus for changing the swirl, in particular swirl amplification/swirl generation or swirl reduction/swirl elimination.

The object is also achieved by creating a turbocharger which has a media splitting machine according to the invention or a media splitting machine according to one of the exemplary embodiments described above. The media splitting machine is arranged upstream of a compressor wheel of the turbocharger. The media splitting machine is used in particular for the electromotive support of the compression of the turbocharger, with the air to be compressed flowing through the media gap of the media splitting machine during operation of the same. In this configuration, the advantages already explained above in connection with the media splitting machine are realized in a special way.

The turbocharger is preferably designed as an exhaust gas turbocharger of a power generation device, in particular an internal combustion engine or a fuel cell.

According to a development of the invention, it is provided that the rotor of the media splitting machine is non-rotatably connected to the shaft of the compressor wheel. This represents a particularly compact and simple design of the turbocharger in combination with the media splitting machine.

Finally, the object is also achieved by creating a power generation device that has a turbocharger according to the invention or a turbocharger according to one of the exemplary embodiments described above. The advantages already explained in connection with the media splitting machine and the turbocharger result in particular in connection with the power generation device.

According to a preferred embodiment, the power generation device is an internal combustion engine. According to another preferred embodiment, the power generation device is a fuel cell.

The invention is explained in more detail below with reference to the drawing. The single figure shows a schematic representation of an exemplary embodiment of a power generation device with an exemplary embodiment of a turbocharger that has an exemplary embodiment of a media splitting machine.

The only figure shows a schematic detailed illustration of an exemplary embodiment of a power generation device 1 designed as an internal combustion engine, which has a turbocharger 3 . In particular, a compressor wheel 5 of the turbocharger 3 is shown.

Alternatively, the power generation device can be in the form of a fuel cell.

The turbocharger 3 has a media splitting machine 7 which is arranged upstream of the compressor wheel 5 in such a way that combustion air flowing to the compressor wheel 5 passes through it during operation.

The electrical media splitting machine 7 has a housing 9 in which a rotor 11 is rotatably mounted. In addition, the media splitting machine 7 has a stator 13 fixed to the housing, with a particularly multi-phase drive winding 15 for generating a particularly multi-pole drive magnetic field.

A media gap 17 is formed between the rotor 11 and the stator 13 and encompasses an axis of rotation A of the rotor 11 in an annular manner. The axis of rotation A defines an axial direction. When the media splitting machine 7 is in operation, the media split 17 has a media flow of a medium, in particular combustion air from the internal combustion engine, passing through it. The media gap 17 is therefore penetrated during operation by the combustion air flowing against the compressor wheel 5, i.e. the combustion air flows through the media gap 17 to the compressor wheel 5.

The stator 13 has stator laminations 19, of which only one stator lamina 19 is shown here. At least some of these stator laminations 19, in particular a plurality of the stator laminations 19, which is smaller than a total number of the stator laminations 19 of the stator 13, are designed as guide plates 21. In particular, the stator lamination 19 shown here is designed as a guide plate 21 . The guide plates 21 protrude at least in regions beyond a peripheral wall 23 of the media gap 17 radially inwards into the media gap 17 . In this way, a particularly compact one becomes advantageous Vorleitapparat provided for influencing the media flow in the media gap 17 with high functional integration for the media splitting machine 7, wherein also the magnetic properties of the media splitting machine 7, especially in the interaction between the stator 13 and the rotor 11, are improved. In particular, a magnetic flux of the media splitting machine 7 can be improved.

The guide plates 21 preferably extend in the radial direction up to the rotor 11. In this way, a very particularly favorable magnetic flux for the electric media splitting machine 7 is provided.

The rotor 11 preferably carries a plurality of rotor blades 25 which are arranged on the rotor 11 in a rotationally fixed manner offset axially with respect to the guide plates 21 , that is to say rotate with the rotor 11 during operation of the media splitting machine 7 . These moving blades 25 advantageously form an axial compressor stage, so that overall a two-stage supercharging is provided for the turbocharger 3 in the interaction of the moving blades 25 with the compressor wheel 5 . In this case, the rotor 11 with the moving blades 25 forms a first compressor stage, namely an axial compressor.

The moving blades 25 are preferably arranged upstream of the guide plates 21 in the media gap 17 .

The baffles 21 are preferably shaped and/or adjusted in such a way that the flow of media passing through the media gap 17 is imparted a twist by the baffles 21 when the media splitting machine 7 is in operation. In this way, the baffles 21 act particularly advantageously as an inflow guide for the turbocharger 3 and improve its inflow. In particular, they advantageously shift its surge limit. However, a twist change, in particular also a twist reduction, can also be brought about.

The stator 13, in particular the drive winding 15 of the stator 13, is preferably integrated into the housing 9. This advantageously increases the degree of integration of the media splitting machine 7 and leads to a particularly compact structure.

A flow channel 27 is preferably formed in the housing 9, preferably in the stator 13, which is set up to direct a recirculation flow for the turbocharger 3 along a recirculation flow direction illustrated by a first arrow P1 counter to a media flow direction illustrated by a second arrow P2 of the media flow in the media gap 17 to lead. In this way, a map-stabilizing measure for the turbocharger 3 can advantageously be provided. However, the direction of flow in the flow channel 27 can also reverse at certain operating points. In particular, it is possible for the power generation device 1 to suck air through the flow channel 27 against the arrow PI under full load, which can even contribute to a particularly effective cooling of the stator 13 .

The flow channel 27 preferably passes through the drive winding 15 of the stator 13. In this way, it can preferably contribute to the cooling of the stator 13 and in particular the drive winding 15.

The rotor 11 is preferably non-rotatably connected to a shaft 29 of the compressor wheel 5 .

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 202015101916 U1 [0004]

Claims (11)

Electric media splitting machine (7) for a turbocharger (3), in particular an exhaust gas turbocharger of a power generation device (1). - A housing (9), wherein in the housing (9) a rotor (11) is rotatably mounted, and with - A housing-fixed stator (13) having a drive winding (15) for generating a drive magnetic field, wherein - Between the rotor (11) and the stator (13), a media gap (17) is formed which annularly encompasses an axis of rotation (A) of the rotor (11) and through which a media flow of a medium passes during operation of the media splitting machine (7), wherein - The stator (13) has stator laminations (19), wherein - A plurality of stator laminations (19) is designed as guide plates (21), wherein - the guide plates (21) at least in some areas project radially inwards into the media gap (17) beyond a peripheral wall (23) of the media gap (17). Media splitting machine (7) after claim 1 , wherein the baffles (21) extend in the radial direction up to the rotor (11). Media splitting machine (7) according to one of the preceding claims, wherein the rotor (11) carries a plurality of rotor blades (25) which are offset axially to the guide plates (21) and non-rotatably arranged on the rotor (11). Media splitting machine (7) according to one of the preceding claims, wherein the rotor blades (25) are arranged upstream of the baffles (21) in the media gap (17). Media splitting machine (7) according to one of the preceding claims, wherein the baffles (21) are shaped and/or adjusted in such a way that the media flow passing through the media gap (17) undergoes a twist change through the baffles (21) during operation of the media splitting machine (7). Media splitting machine (7) according to one of the preceding claims, in which the stator (13), in particular the drive winding (15) of the stator (13), is integrated into the housing (9). Media splitting machine (7) according to one of the preceding claims, wherein a flow channel (27) is formed in the housing (9), preferably in the stator (13), which is set up to create a recirculation flow for the turbocharger (3) along a recirculation flow direction to lead against a media flow direction of the media flow in the media gap (17). Media splitting machine (7) according to one of the preceding claims, wherein the flow channel (27) passes through the drive winding (15) of the stator (13). Turbocharger (3), in particular exhaust gas turbocharger of a power generation device (1), with a media splitting machine (7) according to one of the preceding claims, wherein the media splitting machine (7) is arranged upstream of a compressor wheel (5) of the turbocharger (3). Turbocharger (3) after claim 9 , wherein the rotor (11) of the media splitting machine (7) is non-rotatably connected to a shaft (29) of the compressor wheel (5). Power generation device (1), with a turbocharger (3) according to one of claims 9 or 10 .

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