DE102019131138A1 - Rotor, electric rotary machine and drive assembly - Google Patents

Abstract

The invention relates to a rotor of an electric rotary machine, an electric rotary machine and a drive arrangement for a motor vehicle that can be driven by an electric motor. The rotor (1) of an electric rotary machine comprises at least one stacking arrangement (20) of rotor laminations arranged along an axis of rotation (2) of the rotor (1) (22) and on at least one axial side of the stack arrangement (20) a pressure element (10), with which an axial pressure force on the stack arrangement (20) is brought about or can be brought about, the pressure element (10) having a first shaped element (11) and the stacked arrangement (20) has a second shaped element (21), the two shaped elements (11, 21) each have an axial extension and along the axial direction of one of the two shaped elements (11, 21) at least in sections in the other shaped element (11, 21) ) is positioned. With the rotor according to the invention and the electric rotary machine can be constructively e ensure a long service life as well as reliable and measurable operation in a simple and cost-effective manner.

Description

The invention relates to a rotor of an electric rotary machine, an electric rotary machine and a drive arrangement for a motor vehicle that can be driven by an electric motor.

Various electrical rotary machines which have a rotor are known from the prior art.

A rotor of an electric rotating machine is generally constructed in such a way that it has a plurality of stack arrangements which, arranged coaxially to one another, form the rotor body. A respective stack arrangement is known to be composed of several individual sheets and can also be referred to as a so-called stack or rotor stack.

Permanent magnets or wire windings, which are exposed to a magnetic field of a stator of the rotating electrical machine, extend through the stacking arrangement of the metal sheets.

When the electric rotary machine is in operation, magnetic fields that occur can cause individual metal sheets, in particular a stack arrangement arranged axially at the end, to tilt relative to one another.

The prior art knows several ways of securing the axial positions of the metal sheets with respect to one another and of the stacking arrangements with respect to one another.

For example, it is known to bake the stack assemblies with a so-called baking varnish. A layer of baked enamel surrounds the individual stack arrangements or the rotor, so that the positions of the individual sheets of the respective stack arrangement are secured with respect to one another. However, the baking process is associated with a lot of effort.

It is also known to provide a plurality of axially extending weld seams on the radial outside of the rotor, which weld seams connect the stack assemblies and their sheets to one another. In this case, however, sheet metal sheets can still tilt in the circumferential direction between two weld seams. In order to reliably prevent individual metal sheets from tilting relative to one another, a corresponding number of such weld seams must be applied.

A third known solution is the arrangement of a cover plate on an axial end face of an axially outer stack arrangement. The cover plate is acted upon by a force in the axial direction on the stacking arrangements, so that the positions of the stacking arrangements and their metal sheets are secured with respect to one another. The cover plate thus functions as a pressure element in the axial direction. Such a cover plate must be secured in its position in relation to the rotor, which is usually implemented in such a way that the respective cover plate is tensioned against the stack arrangement on a shaft carrying the rotor or on a rotor carrier carrying the rotor, with an anti-rotation lock between the Shaft or the rotor arm and the cover plate is realized.

In a known embodiment, the anti-rotation device is implemented by a projection on the cover plate, which engages in a positive-locking manner in the radial direction inward into a recess in the shaft or in the rotor arm. A nut is provided to apply the axial preload force to the cover plate. The nut sits on an external thread of the shaft or of the rotor arm, whereby a normal force is exerted on the cover plate by the nut and thus a frictional connection is realized between the nut and the cover plate.

However, this configuration entails the risk that if there should be play in the anti-rotation device on the shaft or on the rotor arm due to wear, the nut may also be slightly rotated, so that the nut may loosen.

In this situation, there is also a relative rotational movement between the cover plate and the stacking arrangements or the shaft or the rotor arm, which is particularly disadvantageous if a device for detecting the respective angle of rotation is arranged on the cover plate. If there is an angular deviation between the position of the cover plate and the staggered arrangement, the exact angular position of the stacked arrangement can no longer be detected in a corresponding manner.

Proceeding from this, the present invention is based on the object of providing a rotor and an electric rotary machine equipped with it, which guarantee a long service life and reliable and measurable operation in a structurally simple and cost-effective manner.

The object is achieved by the rotor according to the invention according to claim 1. Advantageous configurations of the rotor are specified in subclaims 2 to 8. In addition, an electric rotary machine, which has the rotor, is made available according to claim 9. Furthermore, a drive arrangement, which the electrical A rotary machine as provided in claim 10.

The features of the claims can be combined in any technically meaningful manner, in which case the explanations from the following description and features from the figures can also be used, which include additional embodiments of the invention.

In the context of the present invention, the terms “axial” and “radial” always relate to the axis of rotation of the rotor.

The invention relates to a rotor of an electric rotary machine, comprising at least one stack arrangement of rotor laminations arranged along an axis of rotation of the rotor and a pressure element on at least one axial side of the stack arrangement. With the pressure element, an axial pressure force is brought about or can be brought about on the stack arrangement. The pressure element has a first form element and the stacked arrangement has a second form element, the two form elements each having an axial extent and at least partially positioned in the other form element along the axial direction of one of the two form elements.

This means in particular that one shaped element engages the other shaped element.

A so-called stack can be understood as a stack arrangement.

The axis along which the rotor laminations are arranged parallel to one another corresponds to the axis of rotation of the rotor. The rotor laminations are thus components of the stacked arrangement that are stacked as individual layers.

The pressure element essentially serves to ensure the compact arrangement of the individual rotor laminations in the stack arrangement. The pressure element is designed essentially two-dimensionally. Preferably, the pressure member is made of a non-magnetic material such as an aluminum alloy or a non-magnetic stainless steel.

The pressure element can also be referred to as a cover plate.

The axial engagement of the two shaped elements in one another leads to the shaped elements superimposing one another in the circumferential direction of the rotor, so that the pressure element is entrained in a form-fitting manner when the stack arrangement or the entire rotor is rotated. Correspondingly, the pressure element is carried along in a position radially remote from the axis of rotation when the stack arrangement is rotated. A torque is thus transmitted into the pressure element relatively far radially outward, so that relatively small forces are required in the circumferential direction to apply a counter-torque against the effect of the mass moment of inertia of the pressure element. In a corresponding manner, the shaped elements can be made relatively small, and no or little wear is to be expected on the shaped elements.

Another advantage of this inventive embodiment is that when the pressure element is used as a carrier device of a component of a rotor position sensor, it is ensured that the correct angular position of the stack arrangement can be detected essentially without play due to the entrainment of the pressure element in the rotary movement of the stack arrangement. In particular, the cover element can form the component of the rotor position sensor as an integral component.

According to one aspect of the invention, the first shaped element is a projection and the second shaped element is a recess, so that the projection is positioned in the recess.

In particular, it is provided that the projection and the recess are designed to be complementary in shape and size with regard to their respective cross-section on its or its radially outer contour.

In particular, the projection can be produced by a cutting process in the sheet material of the pressure element and a bending process of a tongue produced thereby from the plane of the pressure element. The recess can be formed for the purpose of reducing the mass of the stack arrangement or the entire rotor and can be formed in all rotor laminations of the stack arrangement and, if appropriate, in all stack arrangements of the rotor. In particular, a respective rotor lamination or a respective stack arrangement can have a plurality of cutouts for the purpose of mass reduction, so that further cutouts are provided in addition to the cutout into which the projection of the pressure element engages. An opening in the pressure element formed by the bending process to produce the projection can optionally be used to implement an inlet or outlet for a cooling fluid from the stack arrangement. Alternatively or additionally, a plurality of fluid openings can be provided in the pressure element, preferably in a radially outer region of the pressure element, through which cooling fluid can exit the stack arrangement or enter the stack arrangement. Besides that, it can Pressure element have a plurality of projections configured essentially identically to one another, these several projections being arranged along the circumference, preferably at regular angular distances from one another, and the stack arrangement correspondingly has several recesses into which the several projections engage axially.

In a further embodiment, the rotor comprises a plurality of stack arrangements aligned parallel to one another.

The rotor laminations of these stack arrangements, also called stacks, are all aligned parallel to one another. By means of the pressure element, a pressure force is applied indirectly to all stack arrangements which are arranged in a row behind the stack arrangement, which is directly acted upon by the pressure element with a pressure force.

In this embodiment it is advisable for a pressure element in the embodiment according to the invention to be arranged axially on both sides of the stacked arrangement package thus formed.

According to a further advantageous embodiment, the rotor comprises a shaft, the axis of rotation of which corresponds to the axis of rotation of the rotor, the shaft having a section with an external thread on which a nut is arranged, which rests axially on the pressure element.

The nut has an internal thread that is complementary to the external thread of the shaft and has at least one surface area with which it can be attached to a contact area of the pressure element, in particular to a radially inner area of the pressure element, which is provided with a central opening through which the shaft passes leads, rests or presses.

In particular, it can be provided that this central opening does not have a shaped element which, in a form-fitting manner, causes the pressure element to be entrained during a rotational movement of the shaft through radial engagement in the shaft. Correspondingly, if there is a relative rotational movement of the stack arrangement in relation to the shaft and the form-fitting entrainment of the pressure element by the form elements on the pressure element and the stack arrangement, no damage can occur in the contact area of the pressure element on the shaft.

In this case, the nut comprises a shoulder formed in the radial direction, on which the radially inner edge of a central opening of the pressure element rests in the radial direction.

This shoulder extends in the axial direction so that the radially inner edge of the pressure element can rest on it.

As a result, centering of the pressure element in relation to the shaft and consequently also to the axis of rotation and, accordingly, also to the stacking arrangement or arrangements via the nut is realized in a simple manner. The surface area of the nut with which the nut can exert the axial pressing force on the pressure element is advantageously provided axially to the side of this shoulder.

The nut itself can, if necessary, directly exert a compressive force axially on the stack arrangement.

In this embodiment, an axial gap can be provided radially on the inside between the pressure element and the stack arrangement, so that the frictional torque caused by the nut on the pressure element when the nut is tightened acts only in the radially outer area of the pressure element on the stack arrangement.

In an alternative embodiment, the nut is axially spaced from the stack arrangement, so that a pressing force is exerted on the stack arrangement only by the pressure element.

However, according to the invention, an embodiment should not be excluded in which the nut has no shoulder on which the pressure element sits with its central opening, but in which the pressure element is arranged exclusively axially next to the nut, so that the pressure element is completely radially inward to reaches the shaft and is centered in a corresponding manner by the shaft itself.

In a supplementary embodiment, the pressure element has at least some sections of the shape of a hollow truncated cone, the nut resting against the area of the smaller diameter of the hollow truncated cone and the pressure element resting with its area of larger diameter against the stacking arrangement.

According to the invention, it should not be ruled out that an intermediate layer, such as a lacquer layer or a sealing layer, may also be arranged between the area of the larger diameter and the stack arrangement.

In particular, in this embodiment it is provided that the pressure element is compressed by the nut, so that the pressure element has the function of a disc spring and with a Spring restoring force exerts a corresponding reaction force on the stack arrangement.

The advantage of this embodiment is that a permanent pressure in the axial direction on the radially outer area of the stack arrangement is brought about, in which an axial resistance of the individual rotor laminations to one another is to be prevented.

The pressure element has the shape of a hollow truncated cone in particular when it is in the untensioned state. In the installed position, it can be deformed by tightening the nut in such a way that it essentially corresponds to a flat or two-dimensional disk.

According to a further embodiment, the first shaped element designed as a projection rests against a radially outer wall of the second shaped element designed as a recess.

In an alternative embodiment, it is provided that the first shaped element, which is embodied as a projection, rests against a radially inner wall of the second shaped element, which is embodied as a recess.

As an alternative or in addition to centering the pressure element on the radially inner region, this configuration also allows centering on the radially outer region of the pressure element.

As a result of the spring force, the projection presses radially outward against the wall of the recess.

This embodiment can be implemented in particular when the pressure element has the shape of a hollow truncated cone, at least in the relaxed state, and is tensioned by tightening the nut so that the projection protruding from an axially lateral boundary surface of the pressure element is pivoted into the recess with a slight pivoting movement. Depending on the realized pivot angle, the projection is also displaced radially outward, as a result of which the pressure element can be centered on the stack arrangement. In addition, this increases a pressing force on the wall of the recess. The pressing force is essentially dependent on the spring constant of the pressure element, which functions here as a plate spring, and on the path of the deformation of the pressure element.

Furthermore, according to the invention, an electric rotary machine is made available which has a stator and a rotor according to the invention. In addition to the rotor according to the invention, the rotary electric machine comprises a stator which is aligned essentially coaxially with the rotor. The electric rotary machine can be designed as an internal rotor motor or also be designed as an external rotor motor. The electric rotary machine can also be designed for a generator function.

In addition, a drive arrangement for a motor vehicle that can be driven by an electric motor, comprising an electric rotary machine according to the invention, is provided.

Further components of the drive arrangement can, depending on the configuration, be an internal combustion engine for a hybrid drive of the motor vehicle, and / or a transmission for stepping up or stepping down the available torque for the purpose of driving the drive wheels of a motor vehicle.

• 1: ein erfindungsgemäßer Rotor in geschnittener Seitenansicht und
• 2: den erfindungsgemäßen Rotor in geschnittener Seitenansicht in einer alternativen Ausführungsform.

The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way restricted by the purely schematic drawings, it being noted that the exemplary embodiments shown in the drawings are not restricted to the dimensions shown. It is shown in

• 1 : a rotor according to the invention in a sectional side view and
• 2 : the rotor according to the invention in a sectional side view in an alternative embodiment.

The rotor according to the invention 1 includes multiple stacking arrangements 20th , a printing element 10 as well as a wave 40 .

The multiple stacking arrangements 20th are along an axis of rotation 2 of the rotor 1 arranged coaxially to one another and axially next to one another and together form a body of the rotor 1 .

A respective stacking arrangement 20th has several rotor laminations 22nd which are arranged parallel to one another and bear against one another in the axial direction. A stacking arrangement 20th is accordingly from a stack of rotor laminations 22nd educated. In the individual rotor sheets 22nd formed axial openings are brought into congruence with one another in the axial direction and are implemented in a respective stack arrangement 20th a recess 23 as well as a recording room 25th . The recesses 23 and recording rooms 25th of the individual stacking arrangements 20th are also brought into congruence with one another in the axial direction, so that they are in the Extend essentially in an axially parallel extension through the entire rotor body.

The recording rooms 25th are arranged radially further out than the recesses 23 .

A respective recording room 25th serves to accommodate a permanent magnet 26th , the permanent magnets 26th when integrating the rotor 1 are in an electric rotating machine with electrically conductive windings of a stator of the electric rotating machine in an operative electromotive relationship. A respective recess 23 serves to reduce the mass of the respective stack arrangement 20th or the entire rotor 1 .

The stacking arrangements 20th are coaxial with the shaft 40 on the radial outside 41 the wave 40 arranged. An axially extending groove 42 on the radial outside 41 the wave 40 into which the stacking arrangements 20th engage radially, serves to prevent rotation of the stack assemblies 20th in relation to the wave 40 . The stacking arrangements 20th and the wave 40 therefore always rotate together around the axis of rotation 2 of the rotor 1 .

Axially next to the stacking arrangements 20th is on the wave 40 also a mother 30th arranged. The wave 40 has an axial section with an external thread 43 on which the mother 30th with a complementary internal thread 31 is arranged.

The mother 30th also forms on her the stacking arrangements 20th facing axial side a radially outwardly facing shoulder 32 out. Axially to the side of this paragraph 32 is a radially extending surface area 33 mother 30th intended.

The pressure element 10 is axially adjacent to the stack assemblies 20th arranged and with the radially inner edge of a central opening 13th through which the wave 40 axially through it, in the radial direction on the shoulder 32 mother 30th arranged. So that is the pressure element 10 through the mother 30th centered and coaxial to the shaft 40 arranged.

The mother 30th lies with its area 33 on a radially extending contact area 14th an axial side of the pressure element 10 on a radially inner region of the pressure element 10 at. The mother 30th presses the pressure element 10 in the axial direction to the axially adjacent stack arrangement 20th , being the mother 30th in the embodiment shown, however, not even on the stacking arrangements 20th is applied. The mother's 30th applied axial force is supported on the side of the stack assembly 20th thus only in the radially outer area of the pressure element 10 from.

The axial position of the pressure element 10 between the mother 30th and the stacking arrangements 20th is thus secured.

Due to the application of force to the pressure element 10 axially through the nut 30th causes the pressure element 10 an axial compressive force on the stack assembly 20th at which the pressure element 10 directly applied, as well as indirectly an axial pressure force on all stack arrangements 20th which are arranged in series behind the immediately axially adjacent stacking arrangement 20th are located. This ensures the compact arrangement of the individual rotor laminations 22nd in the stacking arrangements 20th guaranteed.

It is advisable here to also provide a pressure element and nut designed according to the invention on the axially opposite side of the rotor body.

The pressure element 10 corresponds essentially to a flat or two-dimensional disk, the pressure element 10 at least one extending essentially axially in the direction of the stack arrangements 20th extending protrusion 12th trains. The lead 12th is possibly by a cutting process in the sheet material of the pressure element 10 as well as a bending process of a tongue produced thereby out of the plane of the pressure element 10 generated out. The lead 12th extends in the axial direction into the recess 23 the stacking arrangement 10 or the rotor lamination 22nd on which the pressure element 10 rests against a radially outer wall 24 this recess 23 at.

The lead 12th acts as a first form element 11 and the recess 23 acts as a second feature 21 , wherein the axial engagement of the two form elements 11 , 21 into each other leads to the shape elements 11 , 21 in the circumferential direction of the rotor 1 superimpose one another, so that the pressure element is entrained in a form-fitting manner 10 upon a rotary movement of the stack assemblies 20th or the entire rotor 1 is effected.

The pressure element 10 is thus against a relative rotation in relation to the stack arrangements 20th secured, which means that the printing element 10 and the stacking arrangements 20th always rotate together and without play.

The pressure element 10 optionally furthermore has the function that it comprises a transmitter element, not shown here, of a rotor position sensor as an integral component.

Due to the entrainment of the pressure element 10 in the rotation of the stack assemblies 20th the correct angular position of the stack arrangement is thus essentially free of play 20th detectable.

At the axially outer edge area of the pressure element 10 In the embodiment shown, this has an edge which extends axially with at least one component 15th on. This edge 15th increases the geometrical moment of inertia of the pressure element 10 around one perpendicular to the axis of rotation 2 extending axis and thus ensures a uniform introduction of the pressing force on a circumferential path on the stack arrangement 20th .

Furthermore, through this edge 15th at the same time a flow guide device can be formed for the targeted supply of cooling channels of the rotor 1 exiting cooling fluid in the direction of the windings of the stator of the electric rotary machine.

2 shows the rotor according to the invention 1 in a sectional side view in an alternative embodiment.

This alternative embodiment differs from the rotor 1 according to 1 in that the mother 30th here itself directly also axially on the stack arrangement 20th causes a compressive force.

In this embodiment, on the radially inner side of the pressure element 10 an axial gap between the pressure element 10 and the stacking arrangement 20th be provided to which the pressure element 10 is immediately adjacent.

The pressure element 10 thus lies axially on its radially inner side only on the nut 30th on and radially outside axially on the stack assemblies 20th at.

One from the mother 30th The frictional torque caused thus only acts in the radially outer area between the pressure element 10 and stacking 20th .

With the rotor according to the invention and the electric rotary machine, a long service life and reliable and measurable operation can be ensured in a structurally simple and cost-effective manner.

List of reference symbols

1

rotor

2

Axis of rotation

10

Printing element

11

first form element

12th

head Start

13th

central opening

14th

Attachment area of the printing element

15th

edge

20th

Stacking arrangement

21

second form element

22nd

Rotor lamination

23

Recess

24

Wall of the recess

25th

Recording room

26th

Permanent magnet

30th

mother

31

inner thread

32

paragraph

33

Surface area of the mother

40

wave

41

radial outside of the shaft

42

Groove

43

External thread

Claims (10)

A rotor (1) of an electric rotating machine, comprising at least one stack arrangement (20) of rotor laminations (22) arranged along an axis of rotation (2) of the rotor (1) and a pressure element (10) on at least one axial side of the stack arrangement (20) with which an axial compressive force on the stacked arrangement (20) is or can be brought about, the pressure element (10) having a first shaped element (11) and the stacked arrangement (20) having a second shaped element (21), the two shaped elements (11, 21) each have an axial extent and one of the two shaped elements (11, 21) is positioned at least in sections in the other shaped element (11, 21) along the axial direction. Rotor (1) Claim 1 , characterized in that the first shaped element (11) is a projection (12) and the second shaped element (21) is a recess (23), so that the projection (12) is positioned in the recess (23). Rotor (1) according to one of the preceding claims, characterized in that the rotor (1) comprises a plurality of stack arrangements (20) aligned parallel to one another. Rotor (1) according to one of the preceding claims, characterized in that the rotor (1) comprises a shaft (40), the axis of rotation of which corresponds to the axis of rotation (2) of the rotor (1), the shaft (40) having a section with a Has external thread (43) on which a nut (30) is arranged which rests axially on the pressure element (10). Rotor (1) Claim 4 , characterized in that the nut (30) comprises a shoulder (32) formed in the radial direction, on which the radially inner edge of a central opening (13) of the pressure element (10) rests in the radial direction. Rotor (1) after one of the Claims 4 and 5 , characterized in that the pressure element (10) at least in sections has the shape of a hollow truncated cone, the nut (30) resting against the area of the smaller diameter of the hollow truncated cone and the pressure element (10) with its area of larger diameter resting against the stacking arrangement (20 ) is present. Rotor (1) after one of the Claims 2 to 6th , characterized in that the first shaped element (11) designed as a projection (12) rests against a radially outer wall (24) of the second shaped element (21) designed as a recess (23). Rotor (1) Claim 7 , characterized in that the projection (12) presses radially outward against the wall (24) of the recess (21) due to spring force. Electric rotary machine with a stator and a rotor (1) according to one of the Claims 1 to 8th . Drive arrangement for a motor vehicle drivable by an electric motor, comprising an electric rotary machine according to FIG Claim 9 .

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