WO2017012765A1

WO2017012765A1 - Permanently excited electric machine having optimized geometry

Info

Publication number: WO2017012765A1
Application number: PCT/EP2016/062756
Authority: WO
Inventors: Barlas Turgay; Christian Prag; Sebastian Tabarelli
Original assignee: Robert Bosch Gmbh
Priority date: 2015-07-20
Filing date: 2016-06-06
Publication date: 2017-01-26
Also published as: DE102015213624A1

Abstract

The invention relates to an electric machine (10) having a stator (16) and a rotor (28). The rotor (28) has, per pole (14), a respective first magnetic pocket (34) with a first magnetic element (36) arranged therein and a second magnetic pocket (38) with a second magnetic element (40) arranged therein. The electric machine (10) is characterized in that the first and second magnetic pockets (34, 38) are connected to one another in the circumferential direction and form a common magnetic pair pocket (33), which has a first and second border region (27, 29), which each have a circularly bent edge (84) and an elliptically bent edge (86) in a cross-sectional view. The circularly bent edges (84) are configured where a circumferential web (74) has a minimum thickness (92), and the elliptically bent edges (86) are configured where a radial web (100, 102) and the circumferential web (74) converge. In this way, a torque-optimized electric machine (10) having a high-speed performance can be provided.

Description

description

Permanently energized electric machine with optimized geometry field of the invention

The invention relates to an electrical machine, such as a motor or a generator. In particular, the invention relates to a permanently excited

Synchronous machine.

State of the art

Electrical machines are used in a variety of industrial applications and are increasingly used in the automotive industry as a drive for motor vehicles, such as for hybrid vehicles or for purely electrically powered vehicles.

Electrical machines used in motor vehicles are often configured as permanently excited synchronous machines and have a stator and a rotor rotatably mounted relative to the stator.

The rotors usually have one or more plate packs, too

Rotor packages called, in the longitudinal direction of the rotor stacked laminations on. In the circumferential direction of the rotor spaced recesses of the rotor, so-called magnetic pockets, permanent magnets are arranged, the magnetic fields can be used by interaction with a magnetic field generated by the stator for driving the rotor. Frequently permanently excited electric machines have each pole of the electric machine two V-shaped to each other and each arranged in a magnetic pocket

Permanent magnets on.

In particular, in so-called SMG types of electrical machines (separate motor generator, SMG) is also often a Ganzlochwicklung with a number of holes q = 2 used, creating a magnetic field with low harmonic content or low upper field content in an air gap between the rotor and the stator can. This may also result in that in the

Permanent magnets small eddy current losses or iron losses occur, so that kept a temperature of the permanent magnets low and a inexpensive class of permanent magnets can be used. With increasing number of holes q iron losses and thus total losses of the electric machine can increase at high speeds. DE 10 2012 219 055 AI describes a rotating electrical machine with pro

Pol the electric machine in each case two V-shaped arranged in a rotor permanent magnet. The permanent magnets are arranged in a Magnetpol- opening angle to each other, which has a vertex on a rotor axis.

DISCLOSURE OF THE INVENTION Advantages of the Invention Embodiments of the present invention may advantageously enable to provide a high-speed and / or high mechanical stability optimized electric machine with respect to maximum torque and losses, in particular eddy current losses and / or iron losses.

According to one aspect of the invention, a permanently energized electric machine is proposed, which has a stator which has juxtaposed along a circumference of the stator and in each case by a tooth of the stator spaced grooves, in which grooves one each

Stator winding is arranged. Next, the electric machine has a one

Rotary axis relative to the stator rotatably mounted and concentric with the stator arranged rotor, wherein the rotor per pole of the electric machine each having a first magnetic pocket having disposed therein at least a first magnetic element and a second magnetic pocket having disposed therein at least one second magnetic element. In this case, a radially extending radial web of the rotor is formed between a first edge of each pole and the first magnet pocket and between a second edge of each pole opposite the first edge in the circumferential direction of the rotor and the second magnet pocket. Next, the electric machine has a circumferentially extending the electric machine and the first magnetic pocket and the second magnetic pocket on a

Outer circumference circumferential circumferential ridge on. The electric machine according to the invention is characterized in particular by the fact that the first magnetic pocket and the second magnet pocket of each pole of the electrical machine are connected to each other in the circumferential direction of the electric machine and form a common magnet pair pocket, which has a first edge region and a second peripheral region opposite the first edge region

Edge region, wherein the first edge region and the second edge region in a cross section, e.g. a circular cross-section through the pair of magnetic bags and / or the electric machine, each having a circular curved edge and an elliptically curved edge, wherein the circularly curved edges of the magnetic pair are each formed at a point of the rotor on which the peripheral ridge a measured smallest in the radial direction Has thickness, and wherein the elliptically curved edges of the pair of magnetic bags are each formed at a position at which the radial webs each with the

Collide with each other. The pole of the electric machine can be a magnetic pole and / or a

Designate segment of the electrical machine. The angle of a segment corresponds to 360 ° mechanically divided by the number of magnetic poles of the electric machine. The rotor of the electric machine can be at least one disc pack in

Longitudinal direction of the rotor stacked laminations have, in which the magnetic pockets and / or the magnetic pair pockets, e.g. as punched out, can be introduced. The individual magnetic pockets and / or magnetic pair pockets may extend substantially over an entire length of the rotor and per magnetic pocket, a plurality of

Magnetic elements, e.g. in the form of permanent magnets, in

Longitudinal direction of the rotor arranged side by side and / or stacked on top of each other. The peripheral ridge may partially or fully circulate the magnet pair pockets of each pole of the electrical along the outer circumference. The circumferential ridge may denote an outer region of the rotor and / or of the lamella packet, which surrounds the magnet pair pockets along the outer circumference in FIG

Surround substantially annular and / or can rotate in a ring. The radial webs may be on each edge of a pole of one

Rotor inner diameter extend to the peripheral ridge. The radial webs may be in the circumferential direction opposite edge regions of each pole of the electric machine, which by the disk set - - can be trained. The radial webs can as it were the rotor in the

Essentially spike-like, at least in part.

The circular curved edges of the magnetic pair bag can in a

Cross section through the magnet pair bag circularly curved areas and / or

Designate corners of an outer edge of the respective magnetic pair bag.

Likewise, the elliptically curved edges of the magnet pair bag in a cross section through the magnet pair bag may indicate elliptically curved portions and / or corners of the outer edge of the respective magnet pair bag. The circularly curved edges can each be arranged closer to the stator in the radial direction than the elliptically curved regions. The circular

Curved edges can in each case at those points of

Magnet pair bag be formed, which the stator and / or the

Rotor outside diameters are closest, i. have a minimum distance to the stator and / or the rotor outer diameter. The elliptically curved edges may be located at those locations of the magnetic pair pocket which are furthest apart circumferentially

are spaced. A circumferentially dimensioned distance of the circularly curved edges of each pair of magnetic particles can be smaller than a circumferentially dimensioned distance of the elliptically curved edges.

Ideas for embodiments of the present invention may be considered, inter alia, as being based on the thoughts and findings described below. In permanently excited synchronous machines with two V-shaped magnet elements arranged per pole of the electrical

Machine is to obtain a speed resistance and / or mechanical stability of the electrical machine usually necessary, a web or a central web and / or a bridge between the magnetic elements (or between the

Magnetic pockets) of a pole and / or form in the disk set of the rotor, since due to the V-shaped arrangement, an additional sheet metal mass between the magnetic pockets and a rotor outer diameter can be formed. In other words, the magnetic elements of a pole are usually spaced from each other by the central web in the circumferential direction. In order to ensure a punchability of the magnetic pockets, a thickness of the central web of approximately 0.6 mm to 0.7 mm can generally not be undershot. However, a part of the field lines of the magnetic elements can directly connect from the north pole to the south pole of the magnetic elements (magnetic short circuit) via the center bar, without, for example, a radial direction between rotor and stator arranged gap or air gap to contribute torque generation. In other words, due to the central web, a stray flux can arise, which can not be used for torque generation. According to the invention, this effect can be avoided by eliminating the central web between the magnetic pockets of a pole and by interconnecting the magnetic pockets in the circumferential direction so that the common magnet pair pocket is formed and the stray flux can be kept low or avoided. In addition, by avoiding the leakage flux, a magnetic mass can advantageously be reduced and material costs can be saved.

However, the elimination of the central web between the magnetic pockets of a pole can also reduce a rotational speed resistance and / or mechanical stability of the electrical machine. According to the invention this is compensated by the design of the edge regions of the magnetic pair pocket, each with a circular and an elliptically curved edge, i. the embodiment of the invention

Edge regions can advantageously increase a speed resistance and / or mechanical stability of the rotor. Accordingly, by the inventive design of the electric machine a

Torque density and / or power density to be increased while ensuring the mechanical speed resistance. In other words, an electrical machine with increased reluctance and / or synchronous torque can be provided with simultaneously high mechanical stability.

Furthermore, characteristics of electrical machines, such as the torque and losses of the electric machine, in particular

Eddy current losses and / or iron losses, depending on a variety of the geometry of the electrical machine related variables (geometric variables) and / or parameters. Furthermore, parameters of the electrical machine can compete with each other, ie an optimization of a parameter may result in a deterioration of another parameter. Correspondingly, the geometric parameters and / or parameters of the electrical machine can be optimized and / or selected with regard to a compromise between competing parameters, which can be accomplished, for example, in the context of multi-target optimization. The geometric variables of the electric machine proposed in this invention and described below may represent such an optimization of the electrical machine with respect to the torque and / or a power of the electric machine, wherein the geometric variables, in particular with regard to an iron length, losses, a quality and / or a price of the magnetic elements, a copper mass and / or a torque ripple can represent an optimal compromise. The geometric variables can also be optimized in such a way that, for example, one parameter is optimized while at the same time maximizing other degrees of freedom. In particular, the electric machine according to the invention can be optimized such that it has a high torque density and / or

Power density with high mechanical stability, low losses, inexpensive magnets and / or a low torque ripple may have.

According to one embodiment of the invention, a ratio of a radius of the circularly curved edge to a rotor outer radius of the rotor is between 0.011 and 0.013.

According to one embodiment of the invention, a ratio of a major half axis and / or a major radius of the elliptically curved edge to the rotor outer radius is between 0.016 and 0.018.

According to one embodiment of the invention, the smallest radially measured thickness of the circumferential ridge between the magnet pair pocket and a rotor outer diameter of the rotor is between 0.6 mm and 3.0 mm. The peripheral web can rotate around the magnet pair bag on an outer circumference of the rotor, rotate for example annularly.

According to one embodiment of the invention, a ratio of one

Rotor outside diameter of the rotor to a maximum mechanical speed of the electric machine between 0.01 and 0.04 mm / min ^A -l (0.04 mm * min).

Due to the elimination of the central web between the two magnetic pockets of a pole, it may be advantageous in terms of speed stability and / or mechanical stability of the rotor to widen the web or to increase its thickness measured in the radial direction. Such expansion can be carried out with the aid of the abovementioned ratios according to the invention and / or

geometrical sizes can be realized in an advantageous manner.

According to an embodiment of the invention, an inner pole gap width of the electric machine and an outer pole gap width are each between 0.8 mm and 5.0 mm, and / or a ratio of the inner pole gap width of The electric machine to the outer pole gap width is between 0.3 and 1.8, preferably between 0.3 and 1.79. The inner pole gap width may denote a distance of a radially inner outer edge of at least one of the edge regions of the magnetic pair pocket to the edge of the pole, and the outer pole gap width may be at a distance from a radially outer

Outside edge of at least one of the edge regions of the magnetic pair bag to the edge of the pole denote. The inner and / or the outer pole gap width can each designate a width and / or thickness of at least one of the radial webs. The radially outer outer edge of the magnet pair pocket lies in the radial direction closer to the stator than the radially inner outer edge. The invention

Ratio of the inner to the outer pole gap width can be advantageous to a stability of the electric machine and a torque effect. The inventive dimension of the inner and / or outer pole gap width and their ratio can further beneficial effect on a rotational speed resistance of the rotor.

According to one embodiment of the invention, a ratio of one

Rotor inner diameter of the rotor to a Statoraußendurchmesser the stator between 0.4 and 0.8.

According to one embodiment of the invention, the stator outer diameter is between 110 mm and 500 mm, and / or a ratio of one

Statorinnenendurchmessers to a Statoraußendurchmesser is between 0.6 and 0.9, preferably between 0.64 and 0.88.

The inventive choice of the sizes of the rotor inner diameter ^'of the Statoraußendurchmessers, the Statorinnendurchmessers as well as the ratios indicated above advantageously a torque of the electric machine further optimized and / or may be maximized.

According to one embodiment of the invention, the stator and the rotor are spaced apart in the radial direction of the electric machine via an air gap, wherein a ratio of an air gap in the air gap thickness of the air gap to a stator inner diameter of the stator is between 0.003 and 0.04. This can be done in an advantageous manner

Upper field components are damped and eddy current losses and / or iron losses can be kept low. It can also be increased and / or optimized an efficiency of the electric machine. According to one embodiment of the invention, a hole number of the electric machine is greater than or equal to 0.5. In particular, the electric machine may have a number of holes equal to two, wherein the number of holes may be a number of slots per pole number and strand of the electric machine. By the

According to the choice of the number of holes according to the invention, harmonics of the magnetic field can advantageously be reduced or the magnetic field can have a low upper field component, which in turn can advantageously have an effect on a torque of the electrical machine. This also eddy current losses can be kept low, which can lead to a reduced heating of the magnetic elements during operation of the electrical machine, so that

In particular, inexpensive magnetic elements can be used.

According to one embodiment of the invention, a ratio of a

Magnet pocket height of magnet pair bag to a pole cover the

Magnetic pair bag between 0.03 mm / ° el. (Millimeters per degree electrical) and 0.041 mm / ° el., Preferably between 0.0307 mm / ° el. and 0.0409 mm / ° el .. The

Magnetic pockets may form essentially parallelepipedic recesses in the rotor, which in a cross section through the rotor each extend substantially parallel to one another and parallel to the axis of rotation of the rotor

Have major surfaces on which the magnetic elements can be supported. The pocket height of the magnet can in this case designate a distance of the two main surfaces of at least one of the magnetic pockets of the magnet pair pocket. The pole cover of the magnet pair bag may indicate a common pole cover of the first and second magnet pocket of a pole. The poling of the

Magnetic pair bag may be an angle between a first outer edge of the first magnetic pocket and a second outer edge of the second magnetic pocket

denote, wherein the first and second outer edge of two

opposite edge regions of the pole of the electric machine can be arranged. In other words, the pole cover may designate an angle between a first leg resting against the first outer edge of the first magnetic pocket and a second leg resting against the second outer edge of the second magnetic pocket. The pole cover is typically specified in degrees electrically (° el.), Which can be converted over the number of pole pairs of the electrical machine into mechanical degrees.

Due to the inventive geometry of the electric machine with the inventive ratio of the magnetic pocket height to the poling of the Magnetic pair bag can advantageously be optimized and / or maximized torque of the electric machine. In particular, this can be a reluctance torque of the electric machine optimized and / or maximized, ie, a torque which consists of a geometry of the electric machine or a lamination of the rotor neglecting a on the

Magnetic elements based magnetic torque results. at

Maximizing the reluctance torque may also be magnetic material for the

Magnetic elements can be saved, so that costs for the electrical machine can be saved.

According to one embodiment of the invention, a Polübereckung the first magnetic element and the second magnetic element between 104 ° el. and 126 ° el., preferably between 104.1 ° el. and 125.5 ° el. The Polbedeckung of the first and second magnetic element may denote a common Polübereckung the first and second magnetic element. The pole cover may be at an angle between a first leg which may abut one of the stator at the nearest edge of the first magnetic element, and a second leg, which at one of the stator at the nearest edge of the second

Magnetic element may be present, be measured. Due to the inventively measured Polübereckung of the first and second magnetic element, a torque of the electric machine can be optimized and / or maximized in an advantageous manner.

According to one embodiment of the invention, a Polübereckung the magnetic pair bag is between 145 ° el. and 175 ° el., preferably between 145.7 ° el. and 174.5 ° el ..

According to one embodiment of the invention, the first magnetic element and the second magnetic element are arranged in a V-shape with each other, wherein a V angle of the first magnetic element and the second magnetic element is mechanically between 5 ° mechanical and 28.3 ° mechanical, and / or wherein a Pool pair number of the electric machine is eight. In particular, the V angle can be between 5 ° mechanical (mechanical grade or ⁰ mechanical grade) and 15 ° mechanical. The magnetic elements can be arranged in such a V-shape relative to one another that the V-shape is opened in the direction of the stator. In this case, the V angle can be dimensioned between a horizontal tangent on a stator of the nearest edge of a magnetic element and directed in the direction of the stator main surface of the respective magnetic element. The first - - And second magnetic element can be arranged in such a V-shape to each other that an angle between a longitudinal direction of extension of the first and a longitudinal direction of extension of the second magnetic element a difference of 180 ° mech. and twice the amount of the V angle.

According to an embodiment of the invention, a distance between one of the first and second magnetic elements to a pole center of the pole is between 0 mm and 7 mm. The distance may mean a smallest distance of one of the magnetic elements to the Polmitte, i. The distance may, for example, designate a distance from one of the pole centers on the nearest edge (so-called inner magnetic edge) of at least one of the first and second magnetic elements to the pole center. The

Polmitte may also designate an axis of symmetry of the pole and / or the rotor segment.

According to an embodiment of the invention, the stator has radially outwardly a yoke, which circumferentially rotates the grooves and the teeth of the stator, wherein a ratio of a radially measured thickness of the yoke to a radially metered tooth height of the teeth of the stator between 0 , 5 and 1.5, for example between 0.51 and 1.02. As a result, a magnetic conductivity of the stator can be optimized in an advantageous manner.

According to one embodiment of the invention, a ratio of an average tooth width of the teeth to a radially metered tooth height of the teeth of the stator is between 0.1 and 0.35, preferably between 0.15 and 0.31. The mean tooth width may be half the sum (arithmetic mean) of a radially outer width of a tooth and a radially inner width of the tooth, wherein the respective widths may be dimensioned orthogonal to the radial direction. According to one embodiment of the invention, a ratio of an outer

Groove width to an inner groove width of the grooves of the stator between 0.9 and 1.1. The outer groove width may be a width of the groove at a radially outer edge of the groove and the inner groove width may be a width of the groove at a radial

refer to the inner edge of the groove. The radially inner edge can lie opposite the radially outer in the radial direction. The

Slot widths can each be dimensioned orthogonal to the radial direction.

As a result, the stator magnetic field generated by stator windings arranged in the slots can be further optimized in an advantageous manner. Furthermore, by - - As parallel flanked grooves a larger copper fill factor and thus a lower loss electric machine can be provided.

Brief description of the drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, in which neither the drawings nor the description are to be construed as limiting the invention.

Fig. 1 shows a cross section of a part of an electric machine according to an embodiment of the invention.

2A and 2B each show a detailed view of a cross section through a rotor of an electric machine according to an embodiment of the invention.

The figures are only schematic and not to scale. Same

Reference numerals in the figures designate the same or equivalent features.

Embodiments of the invention

Fig. 1 shows a cross section of a part of an electric machine 10 according to an embodiment of the invention, wherein a segment 12 with a

magnetic pole 14 of the electric machine 10 is shown. The electric machine 10 has a plurality of circumferentially juxtaposed such segments 12. The electric machine 10 may be a permanent-magnet synchronous machine, for example.

The electric machine 10 has a stator 16. The stator 16 has juxtaposed grooves 20 along a circumference of the stator 16, which are spaced from each other by a tooth 18 of the stator 16 and / or separated. In the grooves 20, a stator winding 22 is arranged in each case. Radially outboard, the stator 16 further includes a yoke 24 which rotates the teeth 18 and grooves 20 in the circumferential direction. The yoke 24 may thus designate an outer area of the stator 16.

Further, the electric machine 10 has a rotatably mounted about a rotation axis 26 relative to the stator 16 and concentric with the stator 16 arranged rotor 28. The rotor 28 may have at least one disk pack 30, which - - may consist of a plurality of stacked in the longitudinal direction of the rotor 28 laminations 32. Pro pole 14 of the electric machine 10, the rotor 28 each have a first magnetic pocket 34 having disposed therein at least a first magnetic element 36 and a second

Magnetic pocket 38 with a least a second arranged therein

Magnetic element 40 on. The magnetic pockets 34, 38 may e.g. be introduced as punched in the disk pack 30 and in the laminations 32. The

Magnet pockets 34, 38 may extend substantially over an entire length of the rotor 28 and per magnetic pocket 34, 38, a plurality of magnetic elements 36, 40, such as permanent magnets, in

Longitudinal direction of the rotor 28 may be arranged side by side. The magnetic pockets 34, 38 may each be substantially cuboidal

Form recesses in the rotor 28, which in a cross section through the rotor 28 in each case two substantially parallel to each other and parallel to

Have axis of rotation 26 of the rotor 28 extending main surfaces 42, 44, on which the magnetic elements 36, 40 may be supported. A distance between the two main surfaces 42, 44 is referred to as the magnetic pocket height 46 of a magnetic pocket 34, 38. The two magnetic pockets 34, 38 may also be opposite each other with respect to a Polmitte 90 in the circumferential direction. The magnetic elements 36, 40 may rest against the major surfaces 42, 44 or at least one of

Major surfaces 42, 44, i. a height of the magnetic elements 36, 40 may be smaller than the magnetic pocket height 46.

The first and second magnet pockets 34, 38 of each pole 14 are in

Circumferential direction of the rotor 28 connected together and form a

common magnetic pair pocket 33. The pocket height 46 of the first and second magnetic pockets 34, 38 also indicates the pocket height 46 of the magnetic pair pocket 33. A structural design of the pocket pair 33 is shown in detail in FIGS. 2A and 2B.

The magnet pair bag 33 has a pole cover 48, which is given at an angle between a first outer edge 35 of the first magnet pocket 34 and a second outer edge 39 of the second magnet pocket 38. The first outer edge 35 is at a first edge region 27 of the magnetic pair pocket 33 and the second outer edge 39 is at a second edge region 29 of

Magnetic pair bag 33, wherein the first and second edge region 27, 29 and the first and second outer edge 35, 39 in the circumferential direction

are opposite. In other words, the common pole cover 48 - - An angle between a first on the first outer edge 35 adjacent leg 49 (or a first tangent 49) and a second on the second outer edge 39 adjacent leg 51 (or a second tangent 51) denote. The pole cover 48 is typically specified in degrees electrically (° el.), Which can be converted over a number of pole pairs of the electric machine 10 in mechanical degrees. The pole cover 48 of the

Magnetic pair bag 33 is between 145 ° el. and 175 ° el., preferably between 145.7 ° el. and 174.5 ° el. Further, a ratio of the magnet pocket height 46 to the pole cover 48 of the magnet pair pocket 33 is between 0.03 mm / ° el. and 0.041 mm / ° el. Preferably, the ratio of the magnet pocket height 46 to the common pole cover 48 is between 0.0307 mm / ° el. and 0.0409 mm / ° el. Further, the electric machine 10 has a common pole cover 52 of the first magnetic member 36 and the second magnetic member 40 between 104 ° el. and 126 ° el., preferably between 104 ° el. and 125.5 ° el., on. The

Pole cover 52 may be an angle between a first leg 53 (or a first tangent 53) which may abut a stator 16 at the nearest edge 54 of the first magnetic element 36, and a second leg 55

(or a second tangent 55), which at one of the stator 16 on

nearest edge 56 of the second magnetic element 40 may be dimensioned. The first magnetic element 36 and the second magnetic element 40 are V-shaped to each other, wherein a V-angle 58 of the first magnetic element 36 and the second magnetic element 40 each between 5 ° mech. (Degree meanhan) and 28.3 ° mech., Preferably between 5 ° mech. and 15 ° mech., Is. The V-angle 58 can between a horizontal tangent 59 at the stator 16 on the nearest edge 54, 56 of the magnetic elements 36, 40 and a in

Direction of the stator 16 directed main surface 60 of the respective magnetic element 36, 40 be dimensioned.

Further, a ratio of a stator inner diameter of the stator 16 to a stator outer diameter of the stator 16 is between 0.6 and 0.9, preferably between 0.64 and 0.88. The stator outer diameter of the stator 16 is between 110 mm and 500 mm. - -

The electric machine 10 further has a number of holes greater than or equal to 0.5. In particular, the electric machine 10 may have a number of holes equal to two. A pole pair number of the electric machine 10 may be eight in particular.

The stator 16 and the rotor 28 of the electric machine 10 are spaced from each other in the radial direction by an air gap 62, wherein a ratio of a dimensioned in the radial direction air gap thickness 64 of the air gap 62 to the stator inner diameter of the stator 16 between 0.003 and 0.04.

Between the first outer edge 35 of the first magnetic pocket 34 and a first edge 65 and a first boundary 65 of the pole 14 and between the second outer edge 39 of the second magnetic pocket 38 and a second edge 67 and a second boundary 67 of the pole 14, the electrical Machine 10 each have a pole gap 68. Generally, the pole gap 68 is a distance one of

Outside edges 35, 39 one of the magnetic pockets 34, 38 to one of the edges 65, 67 of the pole 15 of the electric machine 10 denote. Each of the pole gaps 68 has an inner pole gap width 70 and an outer pole gap width 72. The inner pole gap width 70 can be a distance of a radially inner

Outside edge 71 of one of the magnet pockets 34, 38 to each directly adjacent arranged edge 65, 67 of the pole 14 denote, and the outer pole gap width 72 may be a distance of a radially outer outer edge 73 of the magnetic pockets 34, 38 to each directly adjacent edge 65, 67 of Pols 14 designate. The radially outer outer edge 73 lies in the radial direction closer to the stator 16 than the radially inner outer edge 71. A

Ratio of the inner pole gap width 70 to the outer pole gap width 72 is between 0.3 and 1.8, preferably between 0.3 and 1.79. Further, the inner pole gap width 70 and the outer pole gap width are each between 0.8 mm and 5.0 mm.

Between the magnet pair pocket 33 and a rotor outer diameter of the rotor 28, the rotor 28 on a peripheral ridge 74 and web 74, which the

Magnetic pair bag 33 on an outer circumference of the rotor 28 rotates. A smallest radially dimensioned thickness 92 of the circumferential ridge 74 between the magnet pair pocket 33 and the rotor outer diameter of the rotor 28 is between 0.6 mm and 3.0 mm. The thickness 92 may be about a minimum distance of the edge regions 27, 29 of the magnetic pair bag to the rotor outer diameter. - -

Between the first edge 65 of each pole 14 and the first magnet pocket 34 and between the second edge 67 of each pole 14 and the second magnet pocket 38 is in each case a radially extending radial web 100, 102 of the rotor 28 is formed. The radial webs 100, 102 may differ from the

Rotor inner diameter extend to the circumferential ridge 74 in the radial direction and pull through the rotor 28 like a spoke. The inner pole gap width 71 and the outer pole gap width 72 may denote a thickness and / or width of the respective radial web 100, 102.

A ratio of the rotor outer diameter to a maximum mechanical speed of the electric machine is further from 0.01 to 0.04 mm / min ^A -l, and a ratio of the rotor inner diameter to

Stator outer diameter is between 0.4 and 0.8.

Further, a ratio of a radially-dimensioned thickness 25 of the yoke 24 to a radially-dimensioned tooth height 19 of the teeth 18 of the stator 16 is between 0.5 and 1.5, for example between 0.51 and 1.02. The tooth height 19 may designate a length of the teeth 18 dimensioned in the radial direction.

Further, a ratio of an average tooth width of the teeth 18 to the radially-dimensioned tooth height 19 of the teeth 18 of the stator 16 is between 0.1 and 0.35, preferably between 0.15 and 0.31. The tooth width may generally be a distance between two directly adjacent grooves 20. The middle

Teeth width may be as half the sum, i. as an arithmetic mean, a radially outer (maximum) width 76 of a tooth 18 and a radially inner (minimum) width 78 of the tooth 18, wherein the respective widths 76, 78 may be orthogonal to the radial direction.

Further, a ratio of an outer groove width 80 to an inner groove width 82 of the grooves 20 of the stator 16 is between 0.9 and 1.1. The outer groove width 80 may be a width of a groove 20 at a radially outer edge 81 of the groove 20 and the inner groove width 82 may indicate a width of the groove 20 at a radially inner edge 83 of the groove 20. The radially inner edge 83 can thereby lie opposite the radially outer edge 81 in the radial direction. The

Slot widths 80, 82 may each be dimensioned orthogonal to the radial direction. Further, a distance 88 of one of the first and second magnetic members 36, 40 to the pole center 90 is between 0 mm and 7 mm. The distance 88 may be a smallest distance of one of the magnetic elements 36, 40 to Polmitte 90 and approximately from one of the Polmitte 90 nearest edge 91, the so-called. Inner magnetic edge 91, the respective magnetic element 36, 40 are measured to Polmitte 90, wherein the Polmitte 90 may denote about an axis of symmetry of the pole 14 and the rotor segment.

2A and 2B each show a detailed view of a cross section through a rotor 28 of an electric machine 10 according to an embodiment of the invention. In Fig. 2A is a detail view of a cross section through the

Magnetic pair bag 33 shown, and Fig. 2B shows a detailed view of the

Randbereich 29 der Magnetpaartasche 33. Unless otherwise described, the rotor 28 shown in Figs. 2A and 2B may have the same elements and features as that described in Fig. 1.

As clearly shown in FIGS. 2A and 2B, the first edge region 27 and the second edge region 29 of the magnetic pair pocket 33 each have a circularly curved edge 84 and an elliptically curved edge 86 in a cross section through the magnetic pair pocket 33. The circularly curved edge 84 of the first and second edge regions 27, 29 of the magnetic pair pocket 33 is in each case arranged closer to the stator 16 than the respective elliptically curved edge 86 of the first and second edge regions 27, 29. The circularly curved edges 84 of the first and second Edge region 27, 29 or the circularly curved edges 84 of the magnetic pair pocket 33 are each formed at one point of the rotor 28 and / or in each case at a location of the magnetic pair pocket 33, on which the circumferential ridge 74 has the smallest thickness 92 dimensioned in the radial direction. In other words, the circularly curved edges 84 are each arranged at the location of the magnetic pair pocket 33 which has a smallest radial distance to the rotor outer diameter and / or to the stator 16. The circularly curved edges 84 are thus in each case at an outer region 85 closest to the stator 16 and an outer edge 85, respectively

Magnetic pair bag 33 is formed. The elliptically curved edges 86 of the first and second edge regions 27, 29 and the elliptically curved edges 86 of the magnetic pair pocket 33 are respectively formed at a location of the rotor 28 and / or at a location of the magnetic pair pocket 33 at which the radial lands 100, 102 each meet with the peripheral ridge 74. The elliptically curved edges 86 are respectively at the outer edges 73 and the outer regions 73 of the - -

Magnetic pair bag 33 is formed. The elliptically curved edges 86 may in this case denote those edges 86 of the magnetic pair pocket 33 which are closest to the edges 65, 67 of each pole 14 in the circumferential direction or which are spaced furthest apart in the circumferential direction. Furthermore, the circular curved edges 84 and the elliptical

curved edges 86 denote those edges 84, 86 of the magnetic pair pocket 33, which are closest to the stator 16 in the radial direction.

A ratio of a radius of the circularly curved edge 84 to a rotor outer radius of the rotor is between 0.011 and 0.013, and a ratio of a major half axis and a major radius of the elliptically curved edge 86 to the rotor outer radius is between 0.016 and 0.018.

Claims

claims

1. Permanently energized electric machine (10), comprising:

a stator (16) which extends along a circumference of the stator (16)

has juxtaposed and in each case by a tooth (18) of the stator spaced apart grooves (20), in which grooves (20) in each case a stator winding (22) is arranged; and

a rotor (28) rotatably mounted about an axis of rotation (26) relative to the stator (16) and concentric with the stator (16),

wherein the rotor (28) per pole (14) of the electrical machine (10) each have a first magnetic pocket (34) with at least one first magnetic element (36) disposed therein and a second magnetic pocket (38) with at least one second magnetic element disposed therein (40), wherein between a first edge (65) of each pole (14) and the first magnet pocket (34) and between a first edge (65) in

Circumferentially opposite second edge (67) of each pole (14) and the second magnet pocket (38) each one in the radial direction

extending radial web (90, 92) of the rotor (28) is formed,

wherein the rotor (28) has a circumferentially extending and the first magnetic pocket (34) and the second magnetic pocket (38) on a

Outer circumference of the rotor (28) circumferential peripheral web (74), characterized in that

the first magnet pocket (34) and the second magnet pocket (38) of each pole (14) of the electrical machine (10) are interconnected in the circumferential direction of the electrical machine and have a common magnet pocket

Magnet pair bag (33) form, which has a first edge region (27) and a first edge region (27) in the circumferential direction opposite the second edge region (29),

wherein the first edge region (27) and the second edge region (29) have in each case a circularly curved edge (84) and an elliptically curved edge (86) in a cross section through the electric machine (10); wherein the circularly curved edges (84) of the magnetic pair pocket (33) are each formed at a location where the peripheral ridge (74) has a radially-dimensioned smallest thickness (92); and

wherein the elliptically curved edges (86) of the magnetic pair pocket (33) are each formed at a location where the radial lands (90, 92) meet each other with the peripheral land (74). Electric machine (10) according to claim 1,

wherein a ratio of a radius of the circularly curved edge (84) to a rotor outer radius of the rotor is between 0.011 and 0.013;

and or

wherein a ratio of a major half-axis of the elliptically curved edge (86) to the rotor outer radius is between 0.016 and 0.018.

Electric machine according to one of the preceding claims,

the smallest radial thickness (92) of the

Peripheral bar (74) between the magnetic pair bag (33) and a

Rotor outer diameter of the rotor (33) is between 0.6 mm and 3.0 mm; and or

wherein a ratio of a rotor outer diameter of the rotor (28) to a maximum mechanical speed of the electric machine (10) between 0.01 mm / min ^A -l and 0.04 mm / min ^A -l.

An electric machine (10) according to any one of the preceding claims, wherein an inner pole gap width (70) of the electric machine (10) and an outer pole gap width (72) are each between 0.8 mm and 5.0 mm; and or

wherein a ratio of the inner pole gap width (70) of the electric machine (10) to the outer pole gap width (72) is between 0.3 and 1.8.

An electric machine (10) according to any one of the preceding claims, wherein a ratio of a rotor inner diameter of the rotor (28) to a stator outer diameter of the stator (16) is between 0.4 and 0.8;

and or

wherein the stator outer diameter is between 110 mm and 500 mm; and or

wherein a ratio of a stator inner diameter to a

Stator outer diameter is between 0.6 and 0.9.

Electric machine (10) according to one of the preceding claims, wherein the stator (16) and the rotor (28) in the radial direction of the electric machine (10) via an air gap (62) are spaced from each other, and wherein a ratio of one in the radial Direction measured air gap thickness (64) of the air gap (62) to a stator inner diameter of the stator is between 0.003 and 0.04; and or wherein a number of holes of the electric machine (10) is greater than or equal to 0.5.

7. Electrical machine (10) according to one of the preceding claims,

wherein a ratio of a magnetic pocket height (46) of the magnetic pair pocket (33) to a pole cover (48) of the magnetic pair pocket (33) is between 0.03 mm / ° el. and 0.041 mm / ° el. is; and or

wherein a Polübereckung (52) of the first magnetic element (36) and the second magnetic element (40) between 104 ° el. and 126 ° el. is.

8. Electrical machine (10) according to one of the preceding claims,

wherein a Polübereckung (48) of the magnetic pair bag (33) between 145 ° el. and 175 ° el. is.

9. Electrical machine (10) according to one of the preceding claims,

wherein the first magnetic member (36) and the second magnetic member (40) are V-shaped to each other; and

wherein a V-angle (58) of the first magnetic element (36) and the second magnetic element (40) each between 5 ° mech. and 28.3 ° mech. is; and or

wherein a pool pair number of the electric machine (10) is eight.

10. Electrical machine (10) according to one of the preceding claims,

wherein a distance of one of the first and second magnetic members to a pole center (90) of the pole (14) is between 0 mm and 7 mm; and / or wherein the stator (16) has radially outwardly a yoke (24) which circumferentially revolves the grooves (20) and the teeth (18) of the stator (16), wherein a ratio of a radially measured thickness (25 ) of the yoke (24) to a radially metered tooth height (19) of the teeth (18) of the stator (16) is between 0.5 and 1.5.

Electric machine (10) according to one of the preceding claims,

wherein a ratio of an average tooth width of the teeth (18) to a radially dimensioned tooth height (19) of the teeth (18) of the stator (16) is between 0.1 and 0.35; and or

wherein a ratio of an outer groove width (80) to an inner groove width (82) of the grooves (20) of the stator (16) is between 0.9 and 1.1.