EP2920864A2

EP2920864A2 - Transversal flow machine with an improved rotor

Info

Publication number: EP2920864A2
Application number: EP13796019.1A
Authority: EP
Inventors: Martin Braun; Kurt Reutlinger
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2012-11-16
Filing date: 2013-11-12
Publication date: 2015-09-23
Also published as: DE102013206034A1; WO2014076064A3; WO2014076064A2

Abstract

The invention relates to a transversal flow machine (2) comprising a rotor element (4); said rotor element comprises a rotational axis; said rotor element comprises several magnetic elements (8) comprising magnetic poles (10a, b), said magnetic elements being distributed over the periphery of the rotor element; said magnetic poles of the magnetic elements are aligned in the peripheral direction; said magnetic elements (8) with alternating magnetic pole orientation are arranged such that respectively adjacent magnetic poles of two adjacent magnetic elements have identical polarity; a spacer (18, 18a, 18b) is arranged between two adjacent magnetic poles with identical polarity; and two stationary elements (6), the rotor element (4) is arranged between the two stationary elements (6) and at a defined distance therefrom; said stationary elements (6) being designed to ensure the magnetic circuit of a magnetic element (8) closes; the invention being characterised in that the spacers (18, a8a, 18b) are magnetically conductive.

Description

Transverse flux machine with improved rotor

The present invention relates to drive technology in vehicles. In particular, the present invention relates to a transverse flux machine for vehicles, in particular automobiles. Furthermore, in particular, the present invention relates to a transverse flux machine with an improved rotor and a vehicle, in particular an electric or hybrid vehicle with a transverse flux machine according to the invention.

State of the art

Transverse flux machines have long been known. In these, the magnetic flux runs axially and radially and, depending on the design, tangentially via a pole line, such a topology makes it possible to reach the axis of rotation

concentric stator winding. An advantage of transversal flux machines lies in their high torque density and thus high power density at low

Weight and high efficiency.

Here, however, the three-dimensional flow path to the design and installation of such transverse flux machines special requirements, which exist in many different types. For example, document describes

WO 2009/115247 AI a machine as a pancake, which has axial air gaps. On both sides of the rotor is ever a stator of the transverse flux machine. The rotor described there consists of

Permanent magnets embedded in a support structure. However, the magnetic flux is not optimized between rotor and stator

Guided way.

Disclosure of the invention

One aspect of the present invention may thus be seen to provide improved flux control of magnetic flux in a magnetic circuit between magnetic elements in the rotor through the stator. Accordingly, a transverse flux machine and a vehicle, in particular an electric or hybrid vehicle comprising such

Transverse flux machine according to the independent claims. Preferred embodiments will be apparent from the dependent

Claims.

To improve the magnetic flux, the transverse flux machine according to the invention has a rotor element-stator combination with reduced magnetic resistance over the air gap between the rotor and stator elements. Since the magnetic elements are furthermore oriented in the circumferential direction, the rotor according to the invention provides a preferred possibility of influencing the magnetic field lines in their direction after passing through the magnetic elements in such a way that the magnetic field lines change towards the stator element.

One aspect of the present invention is therefore to better guide the path of the magnetic field lines and to reduce the magnetic resistance along the flow path by means of magnetically conductive material.

As a result, either a larger flow in the transverse flux machine can be achieved, which can increase the torque density or the power of the machine, or it can be the amount of magnetic material in the rotor element and thus reduces the cost of the machine at a constant power.

For this purpose, the present invention provides flux guides as a collector arrangement by means of which the magnetic flux in the machine can be increased and better guided.

Based on a transverse flux machine, as shown for example in WO 2009/115247 AI, spacer elements, so-called flux guides of magnetically conductive material are provided in the rotor element according to the invention between the magnetic elements of the rotor. As a result, in the present invention, the path of the field lines is improved by a ferromagnetic material, such as iron, between the

Magnetic elements, the path of the field lines positively influences and directs. In particular, the magnetically conductive flux conducting pieces between two magnetic elements act in such a way that they form a virtual magnetic pole, corresponding to the two, identical magnetic poles which adjoin the flux conducting piece.

In addition, in the flux guide, the field lines can already be directed in the direction of the outer stator elements and thus, unlike the magnetic elements themselves, no longer aligned parallel to the stator, but already, at least partially, inclined in its direction. Since the flux conducting piece itself can thus be regarded as a virtual magnetic pole, this can be regarded as the surface of the flux conducting element adjoining the stator. This already reduces the distance between the actual poles of the magnetic elements of the rotor element and the stator elements.

In the structure according to the invention of a rotor element, the magnetic field lines thus pass through a smaller air gap between the rotor element and the stator element and are otherwise guided by soft magnetic materials, whereby the magnetic field of the magnetic elements is weakened less.

Flux collector or flux collector or flux collector are hereinafter also referred to as spacer elements, in particular between the magnetic elements.

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

Show it

FIGS. 1 a, b show axial views of a rotor element;

Figures 2a-c detailed representations of components of a

Transverse flux machine according to the present invention; Figures 3a, b detailed views of the structure of an inventive

Transverse flux machine with spacers; and

FIGS. 4 a, b show further exemplary embodiments of spacer elements according to the present invention. Figure la shows the axial view of a rotor element with radially continuous magnetic elements. The rotor element 4 has magnetic elements 8, which in the circumferential direction of the

Rotor element 4 are arranged and in each case to each other or to two adjacent magnetic elements have alternating magnetic pole orientation. In other words, two adjacent magnetic elements 8 are each arranged with the same north or south pole to each other. The rotor element may preferably be disc-shaped. The adjacent magnetic poles

10a, b of two adjacent magnetic elements 8 are thus formed the same pole. The individual magnetic elements 8 have a constant angular offset 22 to each other. The axis of rotation of the rotor element 4 is perpendicular to the drawing plane in FIG. 1a.

The magnetic elements 8 may be received in the material of the rotor element 4 or embedded in this, which is formed for example as a fiber-reinforced composite material. In contrast, Figure lb shows the axial view of a rotor element 4 with radially split magnetic elements eighth

The essential difference with respect to Figure la is the division of the integral magnetic elements 8 into individual magnetic elements, e.g. in each case two, wherein in each case one individual magnet element is arranged radially on the inside and another radially outside on the rotor element 4. A magnetic element 8 thus consists of a plurality of magnetic individual elements

different radial position or distance from the axis of rotation of the rotor element 4, these are thus arranged stacked.

In the continuous magnetic elements according to FIG

Stand element come to a flux concentration, while in the case of Figure lb can be saved in shared magnetic elements magnetic material. This is facilitated, in particular, by the fact that in the field of

Statorelementes, in which the stator winding 14 is arranged, no

Magnetic material is because there is responsible for there only a small part of the flow in the transverse flux machine 2. The stator winding will open the stator element 6 is arranged opposite the rotor element 4 between the divided magnetic elements 8.

The circular or plate-shaped rotor element 4 on each side opposite stator elements 6, as shown in Figure 2a.

For simplicity, the axial view of the stator element 6 is shown in Figure 2a stretched. Stator element 6 in this case has return plate 7 or yoke and Distanzverkürzungselemente 16 or teeth, which protrude from the surface of the stator in the direction of the rotor element, on. The

Distance shortening elements 16 are alternately on each side of the

Stator winding 14 arranged and have a constant angular offset 22.

Due to the elongated illustration of Figure 2a, the

Stator winding 14, real designed as a ring winding, and the angular offset 22 as straight, elongated elements or lengths.

An overall arrangement of Figures la / b and Figure 2a is shown in Figure 2b. This is a radial, also elongated view of the machine.

Here, a rotor element 4 is surrounded by two stator elements 6 to one side. The axis of rotation of the rotor element 4 in FIG. 2b is parallel to the plane of the drawing. By way of example, the magnetic field line course 12 is shown in FIG. 2b. This is in the plan view, side view, in the radial direction of the transverse flux machine in the form of an 8.

The radially outer Distanzverkürzungselemente 16 are hereby drawn throughout, while the radially inner

Distanzverkürzungselemente 16 are drawn by dashed lines. The same corresponds to the field lines 12, these are drawn radially outboard continuously, while they are shown radially inwardly dashed lines. The continuous field lines 12 are in this case in the outer part of the machine, thus radially outboard, change in the stator yokes 7, the radial position and run through the inner magnetic element row or magnet half a second time by a magnetic element 8 and are closed via the second stator yoke 7, so that the field line 12 comes back to the beginning and thus also closes.

FIG. 2c shows the combined illustration from FIG. 2a with a rotor element 4 according to FIG. 1b, wherein the carrier material of the rotor element 4 is not shown, and the drawing is shown longitudinally stretched.

Also in Figure 2c, the magnetic field lines 12 are shown. The field lines 12 emerge from the north poles of the magnetic elements 8 are transferred by the Distanzverkürzungselemente 16 and the stator teeth in the stator 6, change in the yoke 7, the radial position and pass through the second row of teeth of the stator back to the rotor element 8. There, the field lines 12 go to the south poles of the magnetic elements 8, which corresponds to only half of a "8" - form shown above.

With further reference to FIGS. 3 a, b, detailed representations of the structure of a transverse flux machine according to the invention are shown with spacing elements or flux-conducting elements.

FIGS. 3 a, 3 b substantially correspond to the representation of FIG. 2 b, wherein the spaces between the magnetic elements 8 do not correspond to the rotor carrier material, but rather by spacer elements 18 or

Flux guiding elements are bridged or filled. As a result of the two identical poles of the individual magnet elements 8, which adjoin a spacer element 18 in each case, the flux guide itself forms a virtual magnetic pole which, however, as shown in FIG

Distance connecting elements 16 and the teeth of the stator 6 is arranged. This reduces the magnetically active air gap 17 between the rotor element 8 and the distance shortening elements 16 of the stator elements 6.

Preferably, the flux-guiding elements are made of a soft magnetic composite (SMC) material, since losses due to alternating components or field changes during operation in the flux-conducting elements cause only small losses due to eddy currents. The spacer elements 18 can either be designed as simple intermediate elements between the magnetic elements 8 of the rotor element 4, as shown in FIG. 3 a, or a widening beyond the magnetic elements 8 to the air gap 17 or into the air gap 17 and thus to the distance shortening elements 16 the stator elements 6, whereby the magnetic air gap resistance 17 is further reduced.

This widening can either be designed such that the flux guide elements 18 wider than the gap between two

Magnet elements 8 is formed and thus includes or overlaps this, simultaneously or additionally, the flux guide 18b also protrude in the direction of the stator elements 6, the magnetic elements 8 and thus the

Approximate distance shortening elements 16 to the magnetic

Air gap 17 further to reduce. This broadening thus facilitates the transition of the magnetic flux via the air gap 17, since, for example, shown in Figure 3b, the flux guide 18 b provide the flow 12 a larger cross-sectional area than, for example, in Fig. 3a

Still referring to Figures 4a, b are further exemplary ones

Embodiments of spacer elements according to the present invention shown.

The flux directors 18 may alternatively be used e.g. have centrally a cavity or an opening 20 which, for example, carrier material of the

Rotor element 8, e.g. Fiber material, record and so contribute to improving the mechanical properties.

A flux guide 18, as shown in Figure 4b, in turn, be composed of several individual pieces, while having an opening 20 at the same time. Due to the consisting of several sections

Fluxing 18, a preferred assembly may be possible.

Taking into account FIG. 1b, flux-conducting elements 18 can alternatively also be made radially split. The flux guide elements 18 of FIGS. 4a, b are shown in such a way as they would be oriented or arranged in their use in FIGS. 3a, 3b. The opening 20 thus runs radially outward and can absorb eg fiber material.

Claims

Transverse flux machine (2), comprising

a rotor element (4);

wherein the rotor element has a rotation axis;

wherein the rotor element comprises

a plurality of magnetic elements (8) having magnetic poles (10a, b),

wherein the magnetic elements are distributed over the circumference of the rotor element;

wherein the magnetic poles of the magnetic elements are aligned in the circumferential direction; and

wherein the magnetic elements (8) with alternating

Magnetpolorientierung are arranged so that each adjacent magnetic poles of two adjacent magnetic elements are formed polgleich;

wherein in each case a spacer element (18, 18a, 18b) is arranged between two adjacent pole-like magnetic poles; and

two upright elements (6),

wherein the rotor element (4) is arranged between the two stator elements (6) and spaced therefrom in a defined manner;

wherein the stator elements (6) are arranged to provide a termination of the magnetic circuit of a magnetic element (8);

characterized in that

the spacer elements (18, 18a, 18b) are formed magnetically conductive.

Transverse flux machine according to claim 1, wherein the spacer elements (18) are adapted to reduce a magnetic resistance via the air gap (17) between the rotor element (4) and stator elements (6).

Transverse flux machine according to claim 1 or 2, wherein the

Stator elements (6) have Distanzverkürzungselemente (16) which protrude axially in the direction of the rotor element (4) and for receiving

Magnetic field lines are set up; and

wherein the spacer elements (18, 18a, 18b) are arranged, the

Air gap resistance (17) between magnetic elements (8) and

To reduce distance shortening elements (16).

4. Transverse flux machine according to one of the preceding claims, wherein the spacer elements (18, 18 a, 18 b) consist of a ferromagnetic material or of a soft magnetic composite (SMC) material.

5. Transversal flux machine according to one of the preceding claims, wherein the spacer elements (18) have an opening (20).

6. Transverse flux machine according to claim 5, wherein the opening (20) is filled with magnetically non-conductive or poorly conductive material.

7. transverse flux machine according to one of the preceding claims, wherein the spacer elements (18) are each formed of a plurality of individual elements.

8. transverse flux machine according to one of the preceding claims, wherein the spacer elements (18) are formed substantially flush with the magnetic elements (8). 9. transverse flux machine according to one of the preceding claims, wherein the spacer elements (18) via the magnetic elements (8) in the direction of at least one stator element (6) are formed protruding.

10. Transverse flux machine according to one of the preceding claims, wherein a magnetic element (8) of a plurality of radially divided

Individual elements is formed.

1 1. Transverse flux machine according to one of claims 3 to 10, wherein the Distanzverkürzungselemente (16) are arranged in non-conductive material or coated therewith.

12. Vehicle, in particular electric vehicle or hybrid vehicle, comprising a transverse flux machine (2) according to one of the preceding claims