WO2021056039A1

WO2021056039A1 - Electric machine

Info

Publication number: WO2021056039A1
Application number: PCT/AT2020/060336
Authority: WO
Inventors: Christian DORFBAUER; Dietmar Andessner; Gerold Stetina; Philipp Lucas Frühwirth
Original assignee: Miba Emobility Gmbh
Priority date: 2019-09-27
Filing date: 2020-09-16
Publication date: 2021-04-01
Also published as: AT523028A1

Abstract

The invention relates to an electric machine (1) comprising a rotor (4) and a stator (3). The stator (3) has multiple stator poles which are distributed over the circumference of the stator (3), and the stator poles are mutually spaced, thereby forming intermediate spaces (11). A first gear wheel (10) is arranged radially below the stator poles, said gear wheel being driven by the rotor (4), and a transmission element is arranged between the stator poles in at least one of the intermediate spaces (11) in order to transmit the rotational movement of the first gear wheel (10) to another gear wheel (12).

Description

ELECTRIC MACHINE

The invention relates to an electrical machine, in particular an axial flux machine, comprising a rotor and a stator, the stator having a plurality of stator poles which are arranged distributed over the circumference of the stator, the stator poles being spaced apart from one another with the formation of gaps, and being radially a first gear wheel is arranged below the stator poles and is driven by the rotor.

Electrically powered systems often work with DC motors that are operated at very high speeds (up to 20,000 rpm). In order to bring the high speed to the application-specific lower speed, gears are used that have gear ratios of up to 1: 1,000. The space required for such drives is correspondingly large.

Hybrid machines are also known from the prior art. For example, US 2016/072362 A1 describes a hybrid axial flux generator, comprising one or more axial flux generators, the generator comprising at least one rotor with one or more magnets, and wherein the rotor furthermore comprises at least one toothed wheel, a toothed belt pulley, a belt pulley Sprocket comprising a friction wheel as a mechanical energy transfer means. But even here the space requirement of the drive is still relatively large.

The present invention is based on the object of providing an electrical machine with a mechanical drive that requires little installation space.

This object is achieved in the case of the electrical machine mentioned at the outset in that a transmission element for transmitting the rotational movement of the first gear wheel to a further gear wheel is arranged in at least one of the spaces between the stator poles.

The advantage here is that by utilizing the spaces between the stator poles for the transfer of the mechanical kinetic energy from the first to the next gear wheel, part of a gear, for example a transmission gear, can already be introduced into the electrical machine in a space-saving manner, so that s on one on one Rotor shaft can be dispensed with entirely on the outside gear. This, in turn, enables the overall axial length of the electrical machine to be shortened. An electrical machine can thus also be produced which has fewer moving parts, has a lower noise level and which can transmit high torques, in particular if the electrical machine is an axial flow machine.

To further improve these effects, according to an embodiment of the electrical machine's rule, the first gear wheel is arranged exclusively in the free space that is defined by the inner circumference of the stator and its overall axial length.

In order to be able to use the electrical machine in a wide variety of applications, it can be provided according to design variants that:

- That the first and the further gear wheel are belt wheels and the transmission element is a belt;

- That the first and the further gear wheel are chain wheels and the transmission element is a chain;

- That the first gear wheel is a gear and part of an angular gear, and that the transmission element is a shaft which is connected to a gear of the angular gear.

To increase the transmittable torque, it can be provided in the variant of the electrical machine with the belt drive that the belt wheels are Zahnriemenrä the and the belt is a toothed belt.

In the belt drive variant according to another variant it can also be provided that a belt tensioner and / or a pulley for the belt is arranged radially below the stator poles, whereby damage to the stator coils or the belt due to a belt striking can be avoided.

Likewise, to avoid damage to the stator coils, provision can generally be made for a protective element, in which the transmission element is arranged, to be arranged in the space through which the transmission element is guided. In order to create space for the transmission means for transmitting the mechanical kinetic energy, it can be provided according to further design variants of the electrical machine that the spaces between the stator poles are of different sizes and / or that the magnetic flux collectors are arranged asymmetrically or asymmetrically to one another.

According to a further embodiment variant of the electrical machine that reduces installation space, it can be provided that the rotor is only supported via a bearing element which is arranged on the rotor or on the stator.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

They each show in a simplified, schematic representation:

1 shows a variant embodiment of an electrical machine with a belt drive; FIG. 2 shows a detail of the electrical machine according to FIG. 1;

3 shows a detail of another embodiment variant of the electrical machine;

4 shows an angular gear;

5 shows a detail of an embodiment variant of the electrical machine.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component names, whereby the disclosures contained in the entire description can be applied accordingly to the same parts with the same reference numerals or the same component names. The position details chosen in the description, e.g. above, below, side, etc., refer to the figure immediately described and shown and these position details are to be transferred accordingly to the new position if there is a change in position.

1 and 2 show an electrical machine 1 (hereinafter only machine 1), in particular an axial flux machine, at least partially. The machine 1 comprises an optional housing 2, a stator 3 and at least one rotor 4. In the embodiment variant shown, the axial flux machine 1 comprises only one stator 3. However, it is also possible that the machine 1 has two stators 3, between which the rotor 4 is angeord net. In this case, both stators 3 can be designed according to the invention, as will be described in more detail below.

Magnets 5, for example permanent magnets, are arranged on the rotor 4.

The stator 3 has several stator teeth 6, which are only indicated in FIG. 1. These have a coil winding 7 (only indicated schematically in FIG. 2). The stator teeth 6 with the coil windings 7 form the stator poles, so that the stator 3 has a plurality of stator poles which are distributed in a circumferential direction 8 of the stator 3 over its circumference, as can be seen from FIGS. 1 and 2.

The stator 4 also has a, in particular plate-shaped, return element 9 on which the stator teeth 6 rest.

For better utilization of the machine space, the tooth roots and / or the tooth tips can have a larger cross-sectional area than the rest of the stator teeth 6, so that they can be formed prominently (fully).

The tooth roots can also form the return element 12.

The number of stator teeth 6 shown in the figures is not to be understood as limiting. Rather, the number of these depends on the desired performance characteristics of the machine 1.

A first gear wheel 10 is arranged in the center of the machine 1, that is to say radially below the stator teeth 6. This first gear wheel 10 is driven by the rotor 4. For this purpose, it is connected to the rotor 4 in a rotationally fixed manner, for example via a shaft.

The stator poles are arranged at a distance from one another, so that an intermediate space 11 is formed between each of the stator poles.

In order to forward the rotary movement of the first gear wheel 10 to a further gear wheel 12, a traction means 13 is provided in this variant of the machine. The traction means 13 extends through at least one of the intermediate spaces 11. In the embodiment variant shown, a belt is provided as the traction means 13. This is how- placed, in two, in particular adjacent, spaces 11 of the stator 3 ordered, ie one space 11 is used to run out of the traction means 13 from the Sta tor 3 and the other space the return of the traction means 13 in the stator 3, as shown in Fig. 1 is indicated with arrows.

The further gear wheel 12 preferably has a larger diameter than the first gear wheel 10. However, it can also have the same or a smaller diameter as the first gear wheel 10.

Furthermore, the further gear wheel 12 can be connected to a third gear wheel, which in turn can transmit the movement to a fourth gear wheel, etc.

For the variant embodiment of the machine 1 according to FIGS. 1 and 2, a belt is used as traction means 13 for the transmission of the mechanical kinetic energy generated by the first gear wheel 12. Accordingly, in this belt drive, the first and the further gear wheels 10, 12 are designed as belt wheels, for example as V-belt wheels for a V-belt as traction means 13.

There is also the possibility here that the belt is designed as a toothed belt, and consequently the first and the further gear wheel 10, 12 are designed as toothed belt wheels.

Instead of a belt, the belt drive can also have a chain. The first and the further gearwheels 10, 12 are then designed as chain wheels.

Instead of a traction means 13 as the transmission element, a shaft 14 or axle can also be provided, as shown in FIG. 3. The first gear wheel 12 (FIG. 1) is then in contact with a gear wheel 15 of an angular gear 16. This gear wheel 15 is non-rotatably connected to the shaft 14 or the axle. The gear wheel 12 and the gear wheel 15 can be designed, for example, as bevel gears, as shown schematically in FIG.

At its other end, the shaft 14 or the axle has the further gear wheel 12, to which the rotational movement of the gear wheel 10 in the stator is transmitted. However, an angular gear can also be provided at the other end of the shaft 14. As can be seen from FIG. 3, the shaft 14 is again guided through an intermediate space 11 between two stator coils of the stator 3. In contrast to the embodiment variant according to FIGS. 1 and 2 with the looping drive, only one space 11 is required here for the transmission of the rotational movement of the first gear wheel 10.

The first gear wheel 10 is arranged in a free space 17 which is defined by an inner diameter 18 (FIG. 1) of the stator 3, in particular the annular return element 9, and an axial length 19 (FIG. 2). In principle, it is possible here for the first gear wheel to be designed to partially protrude beyond the free space 17. In the preferred embodiment of the machine, the first gear wheel 10 is arranged exclusively in this free space 17. In other words, the first gear wheel 10 does not protrude beyond the stator 3 at any point, that is, neither axially nor radially.

According to an embodiment variant for the execution of the machine 1 with a belt drive, it can be provided that a deflection roller 20 for the belt and / or a belt tensioner is / are arranged radially below the stator poles in the free space 17, in particular exclusively in the free space 17, as this for the pulley 20 dashed lines in Fig. 1 is indicated tet.

In the case of a belt drive with a chain, a chain tensioner can be arranged in the free space 17.

In Fig. 5 a detail of a further embodiment of the machine 1 is shown. In this case, a protective element 21 is arranged in the space 11 between the stator coils, through which the transmission element for transmitting the rotational movement from the first gear wheel 10 to the further gear wheel 12 is guided. In the specific embodiment shown, the protective element 21 is a protective tube and the transmission element is the traction means 13 in the form of a belt. However, this variant is applicable to all variants of the machine 1.

The protective element 21 can also be designed differently, for example as a channel open on one side, as a grid, etc.

Furthermore, the protective element 21 can be arranged exclusively in the stator 3 or led out of this, possibly up to the further gear wheel 12. A protective element 21 is preferably arranged in each intermediate space 11 in which a transmission element for the said transmission of the rotary movement is arranged, so that two protective elements 21 are preferably provided in the machine 1 in the case of a belt drive.

In the embodiment variants of the machine 1 shown in FIGS. 1 to 3, the stator coils are arranged symmetrically distributed in the stator 3. The intermediate spaces 11 are thus all of the same size and in particular have the same width 22 (FIG. 5) in the circumferential direction 8 (FIG. 1). According to a further embodiment variant of the machine, however, there is the possibility that the spaces 11 are of different sizes, in particular have a different width 22 in the circumferential direction 8. Those intermediate spaces 12 are preferably designed with a greater width 22 than the remaining spaces 12, in which a transmission element for the transmission of the rotational movement from the first gear wheel 10 to the further gear wheel 12 is arranged. This can be achieved, for example, through the asymmetrical arrangement of the stator coils or through a smaller design of individual stator coils.

However, it is also possible for magnetic flux collectors 23 of the stator coils to be arranged or designed asymmetrically.

According to a further embodiment variant of the machine 1, it can be provided that the rotor is only supported via a bearing element which is arranged on the rotor or on the stator.

The exemplary embodiments show or describe possible design variants, it being noted at this point that combinations of the individual design variants with one another are also possible.

For the sake of order, it should finally be pointed out that for a better understanding of the structure of the machine 1, this or its details are not necessarily shown to scale. List of reference symbols machine housing stator rotor magnet stator tooth coil winding circumferential direction return element gear wheel gap gear wheel traction means shaft gear wheel angular gear free space inside diameter length deflection roller protection element width flux collector

Claims

Patent claims

1. Electrical machine (1), in particular axial flux machine, comprising a Ro tor (4) and a stator (3), the stator (3) having a plurality of stator poles which are arranged distributed over the circumference of the stator (3), the Stator poles are spaced from each other with the formation of gaps (11), and wherein a first gear wheel (10) is arranged radially below the stator pole, which is driven by the rotor (4), characterized in that in at least one of the gaps (11) A transmission element for transmitting the rotational movement of the first gear wheel (10) to a further gear wheel (12) is arranged between the stator poles.

2. Electrical machine (1) according to claim 1, characterized in that the first gear wheel (10) is arranged exclusively in a free space (17) which is defined by an inner circumference of the stator (3) and its axial length (19).

3. Electrical machine (1) according to claim 1 or 2, characterized in that the first and the further gear wheel (10, 12) are belt wheels and the transmission element is a belt.

4. Electrical machine (1) according to claim 3, characterized in that the Rie menräder are toothed belt wheels and the belt is a toothed belt.

5. Electrical machine (1) according to claim 3 or 4, characterized in that a belt tensioner and / or a pulley (20) for the belt is arranged radially below the stator poles.

6. Electrical machine (1) according to claim 1 or 2, characterized in that the first and the further gear wheel (10, 12) are chain wheels and the transmission element is a chain.

7. Electrical machine (1) according to claim 1 or 2, characterized in that the first gear wheel (10) is a gear and part of an angular gear (16), and that the The transmission element is a shaft (14) which is connected to a gear wheel (15) of the angular gear (16).

8. Electrical machine (1) according to one of claims 1 to 7, characterized in that a protective element (21), in which the transmission element is arranged, is arranged in the intermediate space (11) through which the transmission element is guided.

9. Electrical machine (1) according to one of claims 1 to 8, characterized in that the spaces (11) between the stator poles are of different sizes.

10. Electrical machine (1) according to one of claims 1 to 9, characterized in that the magnetic flux collectors (23) are arranged asymmetrically or are designed asymmetrically to one another.

11. Electrical machine (1) according to one of claims 1 to 5, characterized in that the rotor (4) is mounted only via a bearing element which is arranged on the rotor (4) or on the stator (3).