DE102019126980A1 - Electrical machine, arrangement of a bearing device and method for producing such an electrical machine - Google Patents

Abstract

Electric machine (1) with a stator (10) and a rotor (20), the rotor (20) being rotatably mounted about an axis of rotation (R) by means of at least one bearing device (30), the electric machine (1) being a bearing device (30) and at least one bearing carrier (15), the at least one bearing carrier (15) being arranged at least in sections within the rotor (20), the at least one bearing device (30) in the radial direction between the at least one bearing carrier (15) and the rotor (20) is arranged.

Description

The present invention relates to an electrical machine, an arrangement of a bearing device and a method for producing such an electrical machine.

Electrical machines are well known from the prior art. Typically, electrical machines can be used as generators for generating electrical energy and / or as a drive device in which electrical energy z. B. is implemented in a rotational movement. In particular, rotating electrical machines for this purpose comprise a rotor and a stator, the rotor being supported so that it can rotate about an axis of rotation relative to the stator by means of at least one bearing device. The stator and / or the rotor has at least one coil, preferably a plurality of coils, whereby the rotor and stator generate magnetic fields which repel each other and which can be used, for example, to cause the rotor to rotate relative to the stator.

It is provided in the prior art that the rotor - viewed in mutually opposite end sections in the direction of the axis of rotation - is in each case mounted so as to be rotatable about the axis of rotation via a bearing device.

It was an object of the present invention to provide an electrical machine which is improved over the electrical machines known from the prior art, in particular with regard to economical installation space or with regard to the effort involved in producing the electrical machine and its weight.

This object is achieved by an electrical machine according to claim 1, an arrangement according to claim 9 and a method according to claim 10. Further exemplary embodiments can be found in the dependent claims and the description.

According to a first aspect of the present invention, an electrical machine with a stator and a rotor is provided, the rotor being rotatably mounted about an axis of rotation by means of at least one bearing device, the electrical machine having at least one bearing carrier, the at least one bearing carrier at least partially within of the rotor is arranged, wherein the at least one bearing device is arranged in the radial direction between the at least one bearing carrier, in particular a portion of the at least one bearing carrier arranged inside the rotor, and the rotor.

Compared to the electrical machines known from the prior art, it is provided according to the invention that the at least one bearing carrier is provided, which is arranged inside the rotor. This allows the at least one bearing device to be arranged within the rotor, so that it is not necessary to mount the rotor, in particular the rotor shaft, at its end face in a corresponding external section. Correspondingly, the electrical machine can be dimensioned smaller in the direction of the axis of rotation. Furthermore, it is to be regarded as advantageous that by using the at least one bearing carrier and the at least one bearing device, which is arranged within the rotor and thus in the radial direction between the at least one bearing carrier and the rotor, the rotor, in particular in its end section, does not must be adapted in terms of its geometry in order to make it storable for a storage device arranged outside the rotor. Accordingly, it is possible, for example, to dispense with tapering the rotor shaft outside the area of the stator. For example, the stator can be arranged outside the rotor and / or inside the rotor. It is even conceivable that the stator is part of the bearing bracket.

The electrical machine is preferably a rotating electrical machine, the stator and / or rotor of which has at least one coil, the at least one coil being designed to generate a magnetic field. In particular, it is provided that the electrical machine is designed as a drive device with which a drive movement is caused at least temporarily via the rotation of the rotor via the axis of rotation. For example, a vehicle is driven by means of the electric machine. Furthermore, it is conceivable that the electrical machine, in addition to the bearing bracket with the bearing device located on the inside, ie. H. the bearing device, which is arranged inside the rotor, an additional bearing device is provided, which is formed outside of the rotor. Furthermore, it is provided that a gearwheel is connected to the rotor in a rotationally fixed manner, in particular on the end face, in order to transmit a rotational movement, for example to a drive axle.

The bearing device is preferably a plain bearing and / or a roller bearing. In this case, the bearing device comprises, for example, an inner bearing ring and / or an outer bearing ring, the outer bearing ring being arranged on an inner side of the rotor and the inner bearing ring being arranged on an outer side of the bearing carrier. Accordingly, it is conceivable that the bearing inner ring of the bearing device is non-positively, cohesively and / or positively connected to the outside of the bearing bracket is connected and / or the bearing outer ring is non-positively, cohesively and / or positively connected to the inside of the rotor. In the case of a roller bearing, it is conceivable, for example, that it is a needle roller bearing, a ball bearing and / or a cylinder bearing, the roller bodies of which are arranged circumferentially around the outer circumference of the bearing carrier.

In particular, it is provided that the bearing device is formed or placed at the otherwise open end of the rotor, i. E. H. is arranged at the end portion of the rotor, and is preferably flush with the rotor towards the open end. Alternatively, it is conceivable that the bearing device is offset in the direction of the axis of rotation with respect to the front end of the rotor, in particular offset in a direction which is directed into the interior of the rotor. In particular, the design as a flush finish proves to be advantageous for the dimensioning in the direction of the axis of rotation, since no additional installation space has to be taken into account for the offset.

According to a preferred embodiment, it is provided that the rotor is designed as a hollow shaft element or hollow shaft profile, the bearing carrier engaging in an opening on the end of the rotor. It can be the case that the bearing carrier has a section arranged inside the rotor, the extent of which, measured in the direction of the axis of rotation, is less than 50%, preferably less than 40% and, particularly preferably, less than 25% of the extent of the rotor in the direction of the Axis of rotation. In other words: the bearing carrier only protrudes into the end section of the rotor and is used exclusively to support or fasten the bearing device within the rotor shaft at one end of the rotor. It is conceivable that the bearing bracket protrudes into the interior of the rotor, and protrudes in the direction of the axis of rotation inwardly with respect to the bearing device.

It is preferably provided that the bearing bracket is tubular. This makes it possible in an advantageous manner to save material and weight, since a massive design of the bearing bracket is dispensed with. For this purpose, the bearing carrier is preferably forged in order to induce a corresponding microstructure that withstands the corresponding loads during operation of the electrical machine. In addition, the design of the bearing support or the tube section allows the interior of the bearing support to be used to guide a cooling fluid, which in turn can be used to cool the electrical machine from the inside. Furthermore, it is preferably provided that the bearing bracket is in one piece. It is also conceivable that the bearing carrier is configured in several parts, for example as a hybrid component with a first section and a second section, the first section and the second section being made of different materials. The bearing bracket is preferably made of a metal.

It is also conceivable that the bearing bracket has a wall with interruptions. I. E. In the direction of rotation, the wall of the bearing bracket is interrupted or has free spaces. This further reduces the weight of the electrical machine. For example, the free spaces are provided in the section of the bearing carrier that is surrounded by the rotor and that carries the bearing device.

It is also conceivable that the outside of the bearing carrier is structured or profiled, in particular to form a receptacle and / or a form fit with the bearing device. For example, the bearing bracket has a circumferential groove or groove on its outside, into which, for example, the bearing device can be inserted. In other words: the bearing device, in particular its inner ring, is at least partially sunk into the bearing bracket. As a result, not only is a radial expansion of the system comprising the bearing device and bearing carrier reduced, but a form fit in the axial direction is also required. It is also conceivable that the bearing bracket is in two parts and the groove is formed by putting the two parts together. For example, a first part has a reduced outer diameter at its front end. An inner ring can then be pulled onto this reduced outer diameter during assembly. For axial fixation, a second part is then connected to the first part, the second part having means against which the drawn-on inner ring strikes in the axial direction. As a result, a circumferential groove or groove can be implemented in a simple manner on the outside of the bearing carrier, in which the bearing device is advantageously fixed in relation to an axial offset. It is conceivable that, for example, the second part is made of a plastic.

It is also conceivable that the bearing bracket has grooves or grooves or a profile on its inside and / or outside. In this way, for example, a targeted influencing of a cooling fluid flowing through can be carried out on the inside. On the outside, the grooves or the profiling form, for example, a feed system with which a lubricant can be transported to the storage facility. It is also conceivable that a cross section of the bearing carrier widens in the axial direction, in particular within the rotor. As a result, an additional press fit of the bearing device, in particular of the bearing inner ring, can be brought about.

In particular, provision is made for at least one further storage facility to be provided in addition to the at least one storage facility. It is provided in particular that the bearing device is offset in the axial direction with respect to the further bearing device. The at least one bearing device is preferably provided at one end of the rotor, and the further bearing device is arranged at a further end of the rotor opposite the one end. In particular, it is provided that the further bearing device is also arranged between the bearing carrier and the rotor in the radial direction. The bearing bracket is preferably the same bearing bracket that also supports the bearing device. In other words: a single bearing bracket carries both the at least one bearing device and the at least one further bearing device. For this purpose, it is provided in particular that a section of the bearing carrier engaging the rotor extends over more than 50%, preferably more than 60% and, particularly preferably, more than 75% of a total extension of the rotor in the direction of the axis of rotation. As a result of the storage via the at least one bearing device and the at least one further bearing device, it is advantageously possible to dispense entirely with bearing devices that are arranged outside the rotor.

It is particularly preferably provided that the electrical machine comprises at least one channel for a cooling fluid. The interior of the bearing carrier, which is in particular arranged in a stationary manner, preferably forms part of the channel via which this cooling fluid is introduced into the electrical machine. It proves to be particularly advantageous that the bearing bracket is stationary, i. H. without rotating movement, is arranged so that the introduced air is not swirled in the entrance area or in the area of the bearing bracket.

It is particularly preferably provided that at least one raceway for rolling elements is formed on an inside of the rotor and / or on an outside of the bearing carrier. The raceway is preferably forged onto the outside of the bearing carrier and / or the inside of the rotor or is forged integrally with the raw element of the bearing carrier or the rotor. This advantageously makes it possible to dispense with an additional component, for example in the form of a bearing ring, when assembling the electrical machine. This significantly simplifies the manufacture of the electrical machine. It is also conceivable, for example, that the tubular element is crimped or bent at one end in order to form a side delimitation for a roller bearing.

It is preferably provided that the electrical machine has at least one wing element for sucking in a cooling fluid. By means of this vane element, it is advantageously possible to generate a negative pressure within the electrical machine, in particular within the rotor, which induces or at least supports a fluid flow, in particular the cooling fluid, into the interior of the electrical machine. For example, the cooling fluid is air that is required to cool the electrical machine down during operation in order to avoid possible damage.

The at least one vane element is preferably arranged on an inside of the rotor. As a result, the rotational movement of the rotor, which is already present, can advantageously be used to move the wing element, and in particular to generate the desired negative pressure. In this way, air is automatically drawn into the electrical machine during operation or the flow is supported here. For this purpose, the wing elements or lamellar wing elements preferably protrude radially inward from the inside of the rotor. It is preferably conceivable that the wing element is inclined by approximately 45 ° to 70 ° with respect to the axis of rotation. In particular, the wing elements are arranged in the manner of a turbine.

According to a further aspect of the present invention, an arrangement of a bearing device in a rotor is provided, the rotor being mounted so as to be rotatable about an axis of rotation by means of the at least one bearing device, at least one bearing carrier being arranged at least in sections within the rotor, the at least one bearing device in radial direction is arranged between the at least one bearing bracket and the rotor. All the features and advantages that have been described for the electrical machine apply in an analogous manner to the arrangement and vice versa.

According to a further aspect of the present invention, a method for producing an electrical machine is provided, a bearing device being arranged in a rotor according to the invention. All of the features and advantages described for the electrical machine and the arrangement can be transferred analogously to the method and vice versa.

Further advantages and features emerge from the following description of preferred embodiments of the subject matter according to the invention with reference to the attached figures. Individual features of the individual embodiment can be combined with one another within the scope of the invention.

• 1: schematische Darstellung einer elektrischen Maschine gemäß dem Stand der Technik,
• 2: schematische Darstellung einer elektrischen Maschine gemäß einer ersten beispielhaften Ausführungsform der vorliegenden Erfindung und
• 3 schematische Darstellung einer elektrischen Maschine gemäß einer zweiten beispielhaften Ausführungsform der vorliegenden Erfindung.

It shows:

• 1 : schematic representation of an electrical machine according to the state of the art,
• 2 : a schematic representation of an electrical machine according to a first exemplary embodiment of the present invention and
• 3 schematic representation of an electrical machine according to a second exemplary embodiment of the present invention.

In 1 is an electrical machine 1 shown according to the prior art. Such electrical machines 1 can be used as generators for generating electrical energy or as a drive device using electrical energy. In particular, it is a rotating electrical machine 1 who have favourited a stator 10 and a rotor 20th provides. It is provided here that the stator 10 and / or the rotor 20th Has coils for generating magnetic fields. This makes it possible, for example, to control the coils accordingly to control the magnetic fields of the stator 10 and / or the rotor 20th align such that the repulsive magnetic forces cause a rotation of the rotor 20th around the axis of rotation R. to lead. In the in 1 illustrated embodiment is the rotor 20th designed as a hollow shaft profile or as a hollow shaft. In particular, the rotor extends 20th in the direction of the axis of rotation R. over the end faces of the stator 10 away and is thus on both sides opposite the stator 10 in the direction of the axis of rotation R. in front. To the front sides of the rotor 20th the rotor tapers 20th in order to have cylindrical or sleeve-shaped pipe end sections in the end sections, over which the rotor 20th through appropriate storage facilities 30th around the axis of rotation R. is rotatably mounted. In particular, it is in the in 1 example shown provided that a gear 40 on the face at the end of the rotor 20th connects and rotatably with the rotor 20th is connected in order to transmit the rotational movement generated, for example, to a drive axle, preferably a drive axle of a vehicle.

In 2 is an electrical machine 1 in accordance with a first exemplary embodiment of the present invention. In the 2 illustrated electrical machine 1 differs in particular from the electrical machine 1 that a bearing bracket 15th is provided. It is preferably the bearing bracket 15th around a tubular or sleeve-shaped element. This sleeve-shaped or tubular bearing bracket 15th is at least partially within the rotor, which is designed as a hollow shaft profile 20th arranged. By means of the in the rotor 20th protruding bearing bracket 15th it is advantageously possible to store the rotor 20th about the bearing bracket 15th to undertake. The storage facility is for this purpose 30th seen in the radial direction between the bearing bracket 15th and the rotor 20th arranged. This is particularly the case with the storage facility 30th around a bearing ring, for example a plain bearing and / or roller bearing, such as. B. a needle bearing, ball bearing and / or cylinder bearing. Correspondingly comprises a bearing device designed as a roller bearing 30th a bearing inner ring and a bearing outer ring, the bearing inner ring on an outside AS of the bearing bracket 15th is arranged, and a bearing outer ring on an inside IS of the rotor 20th is arranged or formed. Rolling bodies are then between the bearing inner ring and the bearing outer ring 32 arranged, preferably with a rolling element cage, whereby a rotation of the rotor that is as frictionless as possible 20th around the axis of rotation R. is possible.

Furthermore, it is preferably provided that the bearing bracket 15th in the in 2 Example shown one in the rotor 20th having engaging portion which is smaller than half, preferably than a third, and, particularly preferably, smaller than a quarter of a total length of the rotor 20th in the direction of the axis of rotation R. . The longitudinal section of the bearing bracket is used as the engaging section 15th understood that of the rotor 20th is encased and not from the rotor 20th protrudes. In other words: the bearing bracket 15th only engages in an open end or in the front opening of the rotor 20th one to one end of the rotor 20th (in the in 2 illustrated embodiment that the gear 40 opposite end of the rotor 20th ) rotatable around the axis of rotation R. to store.

Furthermore, it is particularly preferably provided that the bearing bracket 15th Is tubular or sleeve-shaped. In particular, the bearing bracket 15th tubular in such a way that one in the radial direction of the bearing carrier 15th dimensioned wall thickness is smaller than an extension of the storage facility 30th in the radial direction. Such a thin wall for the bearing bracket 15th makes it possible to use a comparatively light electric machine 1 provide. The bearing bracket is preferably used for this 15th Forged in order to guarantee or withstand the corresponding loads that occur during the operation of the electrical machine 1 occur. Furthermore, it is preferably provided that the hollow area or the interior of the tubular bearing carrier 15th is used to flow a cooling fluid, preferably a cooling gas, in particular air, through a fluid stream 38 into the interior of the electrical machine 1 initiate. This makes it possible, particularly simply, to inject a cooling fluid into the interior, in particular the interior of the rotor 20th to introduce, and from the inside out the electric machine 1 to cool. This is particularly advantageous at high speeds. Furthermore, it is particularly preferably provided that the electrical machine 1 at least one wing element 42 has, which is set in rotation to a corresponding negative pressure within the rotor 20th to generate the desired fluid flow 38 to cause and / or support for cooling the electrical machine. The wing elements are preferably used for this purpose 42 or at least one wing element 42 on the inside IS of the rotor 20th formed protruding. Here are the wing elements 42 preferably obliquely to the axis of rotation R. and / or that perpendicular to the axis of rotation R. aligned with the running plane. Furthermore, it is particularly preferably provided that the from the inside IS of the rotor 20th protruding wing elements 42 so far into the interior of the rotor 20th protrude that they are seen in the radial direction from the inside IS of the rotor 20th coming, opposite the inside IS of the bearing bracket 15th protrude.

In 3 is an electrical machine 1 illustrated in accordance with a second exemplary embodiment of the present invention. In particular, the second embodiment differs from the first embodiment in that the bearing bracket 15th one in the rotor 20th has engaging portion which is longer than 40%, preferably 50%, and, particularly preferably, longer than 70% of an extension length of the rotor 20th (in the direction of the axis of rotation R. seen). This makes it possible to use the rotor 20th with at least one storage facility 30th , and with at least one additional storage facility 30` rotatable about the axis of rotation at two points spaced apart from one another in the axial direction R. to store. This makes it possible in an advantageous manner to use any end face on the rotor 20th trained external storage facilities 30th to forego, creating a comparatively space-saving and space-saving electrical machine 1 can be provided. It is particularly preferred that the bearing bracket 15th , especially in the form of a tubular bearing bracket 15th , has one and / or more openings in its pipe wall which allow the fluid flow 38 from inside the bearing bracket 15th can flow radially outward, in particular into an interspace that is delimited from the outside AS of the bearing bracket 15th and the inside IS of the rotor 20th , and in particular between the storage facility 30th and the further bearing device 30 'in the axial direction.

List of reference symbols

1

electric machine

10

stator

15th

Bearing bracket

20th

rotor

30th

Storage facility

30`

further storage facility

32

Rolling elements

38

Fluid flow

40

gear

42

Wing element

IS

inside

AS

Outside

R.

Rotation matter

Claims (10)

Electric machine (1) with a stator (10) and a rotor (20), the rotor (20) being rotatably mounted about an axis of rotation (R) by means of at least one bearing device (30), the electric machine (1) at least one Bearing carrier (15), the at least one bearing carrier (15) being arranged at least in sections within the rotor (20), the at least one bearing device (30) in the radial direction between the at least one bearing carrier (15), in particular one within the rotor (20) arranged portion of the at least one bearing bracket (15), and the rotor (20) is arranged. Electrical machine (1) according to Claim 1 , wherein the rotor (20) is designed as a hollow shaft element, wherein the bearing bracket (15) engages in a front opening of the rotor (20). Electrical machine (1) according to one of the preceding claims, wherein the bearing bracket (30) is tubular. Electrical machine (1) according to one of the preceding claims, wherein in addition to the at least one bearing device (30) at least one further bearing device (30 ') is provided. Electrical machine (1) according to one of the preceding claims, wherein the electrical machine (1) comprises at least one channel for a cooling fluid (38). Electrical machine (1) according to one of the preceding claims, wherein at least one raceway for rolling elements (32) is formed on an inside (IS) of the rotor and / or on an outside (AS) of the bearing carrier (15). Electrical machine (1) according to one of the preceding claims, wherein at least one wing element (42) is provided for sucking in a cooling fluid (38). Electric machine according to Claim 7 , wherein the at least one wing element (42) is arranged on an inner side (IS) of the rotor (20). Arrangement of a bearing device (30) in a rotor (20), the rotor (20) being mounted so as to be rotatable about an axis of rotation (R) by means of the at least one bearing device (30), at least one bearing bracket (15) at least in sections within the rotor ( 20) is arranged, wherein the at least one bearing device (30) is arranged in the radial direction between the at least one bearing carrier (15) and the rotor (20). Method for producing an electrical machine (1), wherein a bearing device (30) in a rotor (20) according to Claim 9 is arranged.

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