EP2115856A2

EP2115856A2 - Electric motor and coil element for said motor

Info

Publication number: EP2115856A2
Application number: EP08707367A
Authority: EP
Inventors: Peter Ortloff
Original assignee: ORTLOFF HELENE; Walter Sohner & Co KG GmbH; Walter Soehner GmbH and Co KG
Current assignee: BINOVA GmbH; Ortloff Helene
Priority date: 2007-01-29
Filing date: 2008-01-29
Publication date: 2009-11-11
Also published as: DE102008032112A1; DE102007004359A1; WO2008092630A2; WO2008092630A3

Abstract

The invention relates to an electric motor with a rotor (1) and a stator (2), comprising at least one stator winding element (21) having coil elements, the rotor and the stator (1, 2) being movable in relation to each other and being interspaced by at least one air gap (23, 24). The coil elements of the stator winding element (21) are configured as pancake coils (21.1, 21.2, 21.3) having flat winding elements (3, 4), individual winding elements consisting of circuit sections that are juxtaposed in one plane, at least the ends (33, 43) thereof being at least partially interconnected. The pancake coils (21.1, 21.2, 21.3) are embedded in a plastic stator base (24) juxtaposed one next to the other. Two types of magnet elements (12.1, 12.2) are present in the rotor, namely elements being of south-north polarization in the radial direction and of north-south polarization in the radius direction, said elements alternating in the peripheral direction of the magnet ring. Preferably, the pancake coils (21.1; 21.2) in the stator winding element (21) are arranged in such a manner that approximately 0.75 to 1.5 pancake coils (21.1; 21.2) lie opposite one magnet element (12.1; 12.2).

Description

Electric motor and coil element for such a motor

The invention relates to an electric motor, in particular a DC motor, with a rotor having at least one magnetic ring with at least one magnetic element, and with a stator having at least one Statorwicklungs- element with coil elements, wherein the rotor and stator against each other movable and through at least one air gap Distance are kept. The invention further relates to a coil element for such a motor.

It should be noted that an electric motor and a generator are to be regarded as similar in construction and thus as machines, which differ only by their operating form, so that the invention - mutatis mutandis - extends to a generator for generating electric power.

The first applications of an ironless engine were provided by Michael Faraday (1791 - 1867). Although the ironless machines functioned reliably and were in no way inferior to the iron-bearing motors and generators the professional world divided into two different sized camps in their advocates and their opponents.

In the 1880s, many proposals for new windings for the three well-known principles of ring, drum and disk windings were filed for patent. In 1887, Nikola Tesla developed the first technically mature three-phase motor in the USA, weighing 380 kg at a power of 7.5 kW.

Iron does not amplify the magnetic field in the sense that it adds a field of its own to the magnetic field of the coil, but only shortens the lossy path of the field lines through the air. The magnetic field lines are real energy lines that lose much of their energy in the air as they move away from the source. Iron has the property to conduct the flow much better than the medium air.

The paradox, however, is that so-called air-coil machines do not have the same volume or diameter of iron machines of the same power. The opposite is true, because with optimal technical implementation of the essence of energy conversion, air-core machines are smaller than iron machines. The reason for this is that air-core machines have a higher efficiency, the z. B. becomes visible in a small design and in a high efficiency.

An engine of the type mentioned is known from German folding brochures of MAACON GmbH, Aschauer Strasse 21, 81549 Munich. These are 3-phase Brushless servomotors (torque motors) for servo applications with high demands on dynamics in a compact design. The windings are specially designed for the application. For certain applications, special sheets with low iron losses are used. Despite these measures, the production is complex. In addition, the cost of materials is high. These torque motors are therefore expensive.

In the German-language leaflet of the EAAT GmbH, Annaberger Strasse 231, 0920 Chemnitz, an ironless linear motor is described in which the primary part ironless is constructed with air coils. This linear motor has neither attraction nor locking forces between the primary and secondary parts. The primary part is directly connected to the mechanical guidance of the carriage.

Motors without magnetic field leading iron sheets are known in conventional construction with high efficiencies and high speeds of the German-based companies Faulhaber and Maxon.

Ironless motors and generators are furthermore known from DE-A-103 51 815 and DE-A-103 35 688.

For brushless motors, there are a variety of published protective rights, especially in the field of small engines. For example, brushless electric motors are known from US-B-3 988 654 and DE-A-10 2005 013, respectively. Such motors can be operated with a control loop. For regulation, information about the rotor ge needed. This information can be determined by current measurement without a position sensor.

It has as its object to develop a motor of the type mentioned so that at least one component of the electric motor minimized and thereby the whole electric motor is simplified in construction, continue to be easier and more effectively to produce stator and rotor.

According to the invention this object is achieved in that in an electric motor of the type mentioned, the coil elements of the stator winding are formed as flat body coils having at least one flat winding element consisting of in an (imaginary) plane adjacent cable trains, in which at least their ends at least partially connected to each other, at least a portion of the flat-body coils are adjacent to each other at least part of their volume embedded in a StatorkunstStoffkörper and two types of magnetic elements are present, namely in the radial direction south-north-polarized and in the north-south polarity in the radial direction, which alternately in Peripheral direction of the magnetic ring are arranged.

Preferably, an assignment is selected in which a part or the entirety of flat body coils is arranged in the stator winding element so that about 0.75 to 1.5 flat body coils each face a magnetic element, so that the ratio of magnet to winding between 3: 4 to 4 : 3. The advantages achieved by the invention are, in particular, that the motor is characterized by compact design, low weight, high efficiency, low environmental impact, high strength, short field lines and closed field line course. The choice of materials results in low production costs. Another advantage is that with low power consumption, a high starting torque is generated. The development result is, for example, a plastic motor with an injection-molded stator as a base part and a rotor made of magnet compound, which is characterized in that the stator and rotor form a construction unit without iron.

The motor can optionally be operated without sensors with commutation or else with sensors and thus for precision positioning.

There is a motor that is a mixture of linear and torque motor. The stator around which the rotor turns is equipped with standing windings. Another advantage is that operation without a sensor is possible, that is, that current measurements are used to determine the position. Another advantage is that the production technology differs from the conventional, that is, no wound coils, no metal housing, but punching technology and injection molding technology can be used in principle. In addition, the annular structure of the rotor and stator do not require special bearings.

A significant advantage is that the engine is made without iron. This is a plastic motor, which is in problematic areas such. B. can be installed in cavities of vehicles in which moisture, dirt, high temperature fluctuations and the like. to rule.

The electric motor is preferably characterized in that the rotor consists of an inner and an outer magnetic ring, which are held on a first support member so that between them, leaving an inner and an outer air gap, the stator is arranged with a Statorwicklungselement.

Notwithstanding this, it is possible that the rotor consists of a magnetic ring which is held on a second support member so that the magnetic ring is disposed leaving an inner and an outer air gap between two stator winding elements of the stator. A further variant is characterized in that the rotor consists of two magnetic ring elements which are held on a carrier element so that they are each arranged leaving four inner stator and one outer air gap between four stator winding elements of the stator.

The fact that the engine is essentially a hollow shaft motor, results in a further space in which a gear or a shaft can be mounted. The engine can also be wheel or disc motor. The disc motor can, for. B. a micromotor with the dimensions 5x2mm be designed as a disc. The opposite magnet rings ensure a straight magnetic field course. In addition, short field lines are possible.

The magnetic elements may consist of magnetizable materials which are formed by plastic-bonded material and which can be alternately magnetized as south-north and north-south-poled magnetic elements. The shaped magnetic ring element is very hard and brittle, so that its strength suffers. Therefore, another ring made of plastic is formed around the magnetic ring element. This structure is manufactured in a two-component injection molding process.

The magnetic ring can consist of the following magnetic materials:

Neodymium Iron Boron (NdFeB)

- Samarium Cobalt (SmCo)

- Aluminum Cobalt (AlNiCo)

- strontium ferrite (StFe)

- Barium ferrite (BaFe)

The invention also relates to a coil element according to the subclaims 14 to 21.

The advantages achieved hereby are in particular that a high degree of material filling and thus a higher efficiency, a better heat dissipation and a higher strength are achieved.

The flat winding elements may be formed in pairs opposite each other, that a winding end of a first flat winding element can be connected to a winding end of a second flat winding element.

The winding start of a second flat winding element of a first flat winding element pair can be connected to the winding start of a folded or flat winding element of a second flat winding element pair. The connection can be made by soldering, ultrasonic welding, pressing.

By these measures, the manufacturing problems are solved in a flat winding, which is actually no winding in the conventional sense. Because wound up in the traditional sense is actually nothing. By elegant manufacturing measures, the cable runs are conducted from the beginning of the flat winding electrically conductive to the end. Cleverly the system of the fallen winding is applied to have continuation of the starts and ends substantially in one plane.

At least one insulating element can be arranged between the flat winding elements. The insulating member may be a sheet member or an insulating varnish, which by dipping, spraying, rolling, printing and / or the like. is applied. If a film is used, the thin film material also presses into the spaces between the cable runs when compressed. The film may be about 1 to 150 microns thick.

The cable runs of the flat winding elements may be made of a conductive material, such. As copper, brass, aluminum, tin, zinc, silver, gold, their mixtures and Compounds and the like be. The cable runs can have a thickness of approx. 0.1 to 2.5 mm.

The flat winding element pairs may be formed as a geometric configuration. The geometric configuration of the flat winding element pairs may be a square, a rectangle, a hexagon, an oval, a circular shape, an octagon, or a trapezoid.

The metal foil used for the flat winding elements may preferably have a thickness between 0.1 to 2.5 mm. If the conditions of use require other thicknesses, these should be used. Between the fallen Flachwicklungs- elements of the flat winding element pairs insulating elements are introduced; the winding package is joined together to form a flat body coil element. In this case, the package can be pressed, so that in a simple manner an insulation between the flat windings and the conductor tracks is brought when a film is used.

The invention will be described below with reference to the drawing. Show it:

1 shows a brushless DC motor in a schematic, seen from above sectional view,

2 shows a partial section B of the rotor and stator of a DC motor according to FIG. 1, FIG. 3 shows a star connection of flat body coils of a stator winding element according to FIG. 1 in a diagrammatically represented side view, FIG.

4 shows a double flat element for a flat body coil according to FIG. 3 in a schematically illustrated plan view, FIG.

Fig. 5 to a flat body coil element connected double flat elements in a schematic, perspective view sideways seen from above and

6 shows a further embodiment of a brushless DC motor in a schematic sectional view seen from the side,

Fig. 7 is a schematic representation of FIG. 1 with a flat winding element in detail.

In Fig. 1, a brushless DC motor is shown. It consists of a rotor 1 and a stator 2, which are rotatable relative to each other and separated by one or more air gaps 22, 23.

The rotor 1 has two adjacent magnetic rings 11, 12, which are arranged on a carrier element (not shown). The inner magnetic ring 11 terminates with an inner ring 14, the outer magnetic ring 12 with an outer ring 13. Both magnetic rings 11, 12 are produced in single or multi-component injection molding, such. B. first, a construction ring made of plastic - to increase the strength even with inlaid metal - and then the magnetic material.

As magnetic materials can be used:

Neodymium Iron Boron (NdFeB)

- Samarium Cobalt (SmCo)

- Aluminum Cobalt (AlNiCo)

- strontium ferrite (StFe)

- Barium ferrite (BaFe)

Is z. As the magnetic ring 12 has been formed, as shown in FIGS. 1 and 2, certain areas are magnetized Siert that alternately in the radial direction N-S-poled magnetic elements 12.1, 12.2 are present as permanent magnets. Each magnetic element here has about a 1 M times the length of a coil element 21.1, 21.2, which form the Statorwicklungs- elements 21.

Leaving two air gaps 22, 23 between two magnetic rings 11, 12 of the stator 2 with a substantially annular stator winding element 21, which consists of coil elements in the form of flat body coils 21.1, 21.2, 21.3, as shown in FIGS. The coil elements are embedded in a stator body 24 made of plastic.

Fig. 3 shows a possible interconnection of the flat-body coils 21.1, 21.2, 21.3 as a star connection. Here, the star point 8 is led out and the U-winding with 5, the V-winding with 6 and the W-winding with 7. A delta connection can also be realized. For special properties, the coil elements can also be controlled individually.

A flat-body coil 21.1 consists of a plurality of interconnected flat winding elements 3, 4, as shown in Fig. 4. Although in the following terms from the conventional coil manufacturing technique such as "winding", "winding", "fall" do not have to be strictly expert, they can best make the relationship from the known to the new.

Thus, the flat winding elements 3, 4 actually no "windings", which are "wound up". Rather, these are two in a plane opposing plurality of circuit traces 31.1, ..., 31. n, 41.1, ..., 41. n, starting from a winding start 32, 42 spaced apart from each other and in a rectangular shape a winding end 33, 43 are guided. Another special feature is that the winding ends 33, 43 are connected to a folding 33/43. This is a flat winding pair 3, 4, which looks like an 8 in the plan view. Of course, other geometric shapes such as a double hexagon or the like. possible.

In order to produce a coil element 21.1 from the flat winding pairs 3, 4, as shown in FIG. 5, the flat winding elements 3, 4 are folded in such a way that a flat winding element 3 comes to rest on a flat winding element 4. The folding 33/43 is the plane of rotation or also fulcrum and comes to lie up. Of course, the folding direction can also be reversed.

If the flat winding pairs 3, 4 are folded, winding start 42 of the second flat winding element 4 is connected to the winding start 32 of the first flat winding element 3 of the following flat winding element pair. In this way, the conductor tracks 31.1, ..., 31. n, 41.1, ..., 4l.n the flat winding pairs 3, 4 part of the respective coil element and thus determine the desired number of turns.

Between the flat winding elements 3, 4 are upper and lower, non-conductive foil elements 34.1, ..., 44.1, ..., 44. n laid and joined together to form a coil package. The joining can be a pressing. The pressing pressure can be varied accordingly. Regardless of the type of assembly is made possible by selecting appropriate materials that the insulating material penetrates into the distances between the cable runs 31.1, ..., 41.1 and the flat winding elements against each other.

The motors can be manufactured in micro construction. A coil package of a coil element can here z. B. have a height of about 10 to 15 mm and a width of about 5 to 10 mm. They can also be produced in macro construction.

FIG. 6 shows a further embodiment 100 of a brushless DC motor. The stator has two opposing paired Statorwicklungsele- 21, which are each held by three stator bodies 24 made of plastic. The stator bodies are molded onto a base element.

The rotor 1 has a carrier element 115 on which a magnetic ring 11 and radially spaced therefrom a second magnetic ring 12 are arranged. These parts are manufactured in a two-component injection molding process. Both magnetic rings 11, 12 move in the limited by the stator winding elements 21 trenches.

This motor 100 is a hollow shaft motor. In the resulting space 26, a gear, a shaft or the like. be recorded.

If necessary, soot pigments, Teflon particles or the like can be dispersed in successive surfaces of the rotor and the stator. As a result, a "maintenance-free lubrication" is realized.

Due to its design, its material and its size, the engine can be used wherever long transit times without accessibility are required.

The production of a "plastic engine", as described in its entirety and in its parts with reference to Fig.l to 6, will be explained below.

I) feeding a thin foil of copper. The film is about 0.2 mm thick. II) etch of flat winding elements pairs, consisting of two opposing flat winding elements 3, 4, the winding ends 33, 43 are connected by a folding point.

III) Elimination of the etchant from the flat coil elements pairs. (Punching may be used instead of the etch-out, in which case the metal foil remnants must be removed.)

IV) Falls of the flat winding element pairs such that the flat winding elements 3, 4 are folded and the winding start 42 of the second flat winding element 4 is connected to the winding start 32 of the first flat winding element 3 of the subsequent flat winding element pair. The winding start of the second flat winding element of a first flat winding element pair is connected to the winding start of the fallen flat winding element of a second flat winding element pair. The connection can be made by soldering, riveting, ultrasonic welding, pressing.

V) inserting foil elements 34.1,..., 34. n, 44.1,... 44.n between the fallen flat winding elements 3, 4 of the flat winding element pairs. The film elements can be about 5 microns thick.

VI) compression of the flat winding elements and the film elements as a winding package to Flachkörperpulen- elements 21.1, 21.2, 21.3. The production of the flat body coil elements is a self-contained manufacturing section.

In the further course of production then becomes

VII) of the plastic ring body 24, in which the flat body coil elements 21.1, 21.2, 21.3 are injected. The plastic presses together with the flat-body coil elements and ensures their cohesion and protection. In this way, all the stator winding elements 21 and the base member of the stator 2 are molded in an injection molding process.

VIII) The magnetic rings 11, 12 and the carrier element 15 holding them are injected to the rotor 1. The shaped magnetic ring is very hard and brittle, so that its strength suffers. Therefore, another ring made of plastic is formed around the magnetic ring. This construction is made in a two-component injection molding process. Subsequently, the magnetizable substances are magnetized to permanent magnets.

IX) Finally, rotor and stator 1, 2 are plugged together to the bearingless plastic motor. Due to the accuracy of fit, the air gaps 22, 23 are extremely small.

Fig. 7 shows schematically the DC motor of FIG. 1 with stator 2 and rotor 1. The stator 2 is a flat winding element 3 removed and shown enlarged. The folded flat-body coils 21 can be seen. By these measures, the manufacturing problems are solved with a flat winding, which is actually no winding in the conventional sense. Because wound up in the traditional sense is actually nothing. As a result of the production measures, the cable runs are guided electrically conductively from the beginning of the flat winding to the end thereof. Cleverly, the system of the fallen or folded winding is applied to have continuation of the starts and ends substantially in one plane.

At least one insulating element can be arranged between the flat winding elements. The insulating element can be a film element, an insulating varnish, by dipping, spraying, rolling, printing and / or the like. be applied. Even a screen printing is possible. If a film is used, the thin film material also presses into the spaces between the cable runs when compressed. The insulating film may be about 0.05 to 150 microns thick.

The cable runs of the flat winding elements may be made of a conductive material, such. As copper, brass, aluminum, tin, zinc, silver, gold, their mixtures and compounds and the like. Be. The cable runs can have a thickness of approx. 0.05 to 2.5 mm.

The flat winding element pairs may be formed as a geometric configuration. The geometric configuration of the flat coil element pairs may be square, rectangular, hexagonal, oval, round, octagonal, trapezoidal, or the like.

Claims

Claims:

1. Electric motor, in particular a DC motor, with a rotor (1) having at least one magnetic ring (11, 12) with at least one magnetic element (12.1, 12.2), and with a stator (2), the at least one stator winding element (21) Coil elements, wherein the rotor and stator (1, 2) against each other and movable by at least one air gap (23,24) are kept at a distance, characterized in that the coil elements of the stator winding element (21) as flat body coils (21.1, 21.2, 21.3) are at least one Flachwicklungs- element (3, 4), consisting of in an (imaginary) plane adjacent line trains (31.1, ... 31. n; 41.1, ... 41. n), in which at least the ends (33, 43) of which are at least partially connected to one another so that at least part of the flat-body coils (21.1, 21.2, 21.3) are embedded side by side in at least part of their volume in a stator plastic body (24) and s two types of magnetic elements (12.1, 12.2) are present, namely in the radial direction south-north-poled and in the radial direction north-south polarized, which are arranged alternately in the peripheral direction of the magnetic ring.

2. Electric motor according to claim 1, characterized in that a part or the entirety of flat Kδrperspulen (21.1, 21.2) in the stator winding element (21) is arranged so that about 0.75 to 1.5 flat body coils (21.1, 21.2) respectively a magnetic element (12.1, 12.2) are opposite.

3. Electric motor according to claim 1 or 2, characterized in that the rotor (1) consists of an inner and an outer magnetic ring (11,12) which are held on a first support member (115) so that between them, leaving a inner and an outer air gap of the (22,23) of the standpipe (2) with a stator winding element (21) is arranged.

4. Electric motor according to claim 1, characterized in that the rotor (1) consists of a magnetic ring (11) which is held on a second carrier element so that the magnetic ring, leaving an inner and an outer air gap between two Statorwicklungselementen (21) of the stator (2) is arranged.

5. Electric motor according to claim 1, characterized in that the rotor (1) consists of two magnetic ring elements (11,12) which are held on a support member (115) so that they each leaving an inner and an outer air gap (23 , 24) are arranged between four stator winding elements (21) of the stator (2).

6. Electric motor according to one of the preceding claims, characterized in that the magnetic elements (21.1, 21.2) consist of magnetized pulverulent substances which form part of a plastic ring (11, 12) formed with plastic and alternately as south-north-polarized and are magnetized as north-south poled magnetic elements.

7. Electric motor according to claim 1, characterized in that the flat winding elements (3,4) are formed opposite each other in pairs, so that a winding end (33) of a first flat winding element to (3) with a winding end

(43) of a second flat winding element (4) is connected.

8. Electric motor according to claim 7, characterized in that the connections of the coil ends

(33,43) are formed as folding points.

9. Electric motor according to one of the preceding claims, characterized in that a winding start (33,42) in the interior of the flat winding element (3, 4) begins.

10. Electric motor according to at least one of the preceding claims, characterized in that the winding start (42) of the second flat winding element (4) of a first Flachwicklungselemente- pair with the winding start (32) of the fallen flat winding element (3) of a second flat winding element pair is connected.

11. Electric motor according to at least one of the preceding claims, characterized in that between the flat winding elements (3,4) at least one insulating element (34.1, ... 34. n; 44.1, ... 44. n) is arranged.

12. Electric motor according to at least one of the preceding claims, characterized in that a flat winding element pair (3, 4) is designed as a planar configuration.

13. Electric motor according to claim 12, characterized in that the planar configuration has the shape of a square, a rectangle, a hexagon, an oval, a circular shape, an octagon, a trapezoid or another polygonal shape.

14. Coil element for an electric motor, in particular a direct current motor, characterized in that the coil elements of the motor are formed as flat body coils (21.1, 21.2, 21.3) having at least one flat winding element (3,4), which in an (imaginary) plane next to each other lying line trains (31.1, ... 31. n, 41.1, ... 41.n), in which at least their ends (33,43) are at least partially connected to each other.

15. coil element according to claim 14, characterized in that the flat winding elements (3,4) are formed in pairs opposite one another, so that a winding end (33) of a first flat winding element is connected to (3) with a winding end (43) of a second flat winding element (4).

16. coil element according to claim 15, characterized in that the connections of the winding ends (33,43) are formed as folding points.

17. coil element according to claim 14, characterized in that a winding start (33,42) in the interior of the flat winding element (3; 4) begins.

18. coil element according to at least one of the preceding claims 14 - 17, characterized in that the winding start (42) of the second flat coil element (4) of a first flat winding element pair with the winding start (32) of the fallen flat winding element (3) of a second flat winding element pair connected is.

19. coil element according to at least one of the preceding claims 14 - 18, characterized in that between the flat winding elements (3,4) at least one insulating element (34.1, ... 34. n; 44.1, ... 44. n) is arranged.

20. coil element according to at least one of the preceding claims 14 - 19, characterized in that a flat winding elements pair (3, 4) is designed as a planar configuration.

21. A coil element according to claim 20, characterized in that the planar configuration has the shape of a square, a rectangle, a hexagon, an oval, a circular shape, an octagon, a trapezoid or another polygonal shape.

22. A method for producing a coil element for an electric motor, in particular a DC motor, characterized by the following steps: a) bringing a film of a conductive material; b) forming flat winding element pairs from the foil, each flat winding element pair consisting of two oppositely lying flat winding elements (3, 4), the winding ends (33, 43) of which are connected or connected by a fold, c) tipping the flat winding element Pairs in the region of the folding point such that the flat winding elements (3,4) are folded and a winding start (42) of a second flat winding element (4) with a winding start (32) of a first Flachwicklungs- element (3) of a subsequent flat winding element pair is connected or is connected.

23. The method according to claim 22, characterized in that after the method step c) a method steps d) is carried out, in which at least between the fallen Flachwicklungs- elements (3,4) of the flat winding element pairs I- solationselemente (34.1, ... 34. n) are introduced and that the folded winding package to a flat body coil (21.1, 21.2, 21.3) is merged.

24. The method according to claim 22, characterized in that the method step b) is carried out by etching or laser cutting.

25. The method according to claim 22, characterized in that the method steps b) is performed by Austanzen.