KR20120106984A - Rotor for modulated pole machine - Google Patents

Abstract

As a rotor for modulating poles, the rotor is configured to generate a rotor magnetic field for interaction with the stator magnetic field of the stator of the modulation poles, the rotor as tubular support structures 201 and 301 forming a circumferential mounting surface. The tubular support structure comprises a plurality of elongate recesses 202 in the mounting surface, the elongate recess arranged in the tubular support structure and the mounting surface of the tubular support structure, extending in the axial direction of the tubular support structure. A plurality of permanent magnets 203 magnetized circumferentially of the rotor to generate a rotor magnetic field, the permanent magnets 203 being axially oriented to direct the rotor magnetic field generated by the permanent magnets in the radial direction. Separated from each other in the circumferential direction of the rotor by a rotor pole section 204 extending to the at least one permanent magnet 203 or one rotor pole section ( 204 includes a plurality of permanent magnets, at least partially extending into one of the plurality of recesses.

Description

ROTOR FOR MODULATED POLE MACHINE}

The present invention relates to a rotor for a modulated pole machine, and more particularly to a rotor for a modulated pole that can be easily manufactured in large quantities.

Over the years, electromechanical designs such as modulating poles, claw pole machines, Lundell machines, and transverse flux machines (TFMs) have become increasingly of interest. Electric machines that use the principles of these machines were earlier started in 1910 by Alexandersson and Fessenden. One of the most important reasons for increasing interest is that the design enables very high torque output, for example in connection with induction machines, switched magnetoresistive machines and even permanent magnet brushless machines. This machine is also advantageous in that coils are often easy to manufacture. However, one of the drawbacks of the design is that they typically experience the need for higher leakage fluxes and more magnetic materials, where they are relatively expensive to manufacture and generate low power factors. Low power factors require larger power electronic circuits (or power supplies when the machines are used simultaneously) that also increase the volume, weight and cost of the total drive.

The modulated electrical pole stator is basically characterized by the use of a central single winding capable of magnetically feeding a plurality of teeth formed by the soft magnetic core structure. The soft magnetic core is then formed around the windings, while for other common electrical mechanical structures the windings are formed around the tooth core section. Examples of modulating polarity forms are often recognized, for example, as claw polarity, Crow-feet-machine, Lundel machine or TFM machine. The modulating pole with embedded magnets is further characterized by an active rotor structure comprising a plurality of permanent magnets separated by a rotor pole section. The active rotor structure is constructed from the same number of segments, while half of the number of segments is made of soft magnetic material and the other half of the segments is made from permanent magnet material. The permanent magnets are arranged such that the magnetization direction of the permanent magnets is substantially circumferential, that is, each of the N pole and the S pole is oriented substantially in the circumferential direction.

Traditionally, rotors are typically made by making 10 to 50 rather large number of individual rotor segments. However, the assembly process is complicated and time consuming because multiple components are combined together resulting in a well formed air gap to preserve the performance of the machine. The assembly process is also complicated by the opposite polarization direction of the permanent magnet segments, which may tend to repel the rotor pole sections from each other during assembly.

WO 2009116935 discloses a rotor and a method for manufacturing the rotor, wherein the number of individual parts is reduced, thereby reducing the time required to assemble the rotor. However, this approach results in increased complexity and cost of the individual parts. Moreover, it can be difficult to reach good overall tolerances because the components can exhibit large variations in cross-sectional area that can lead to unwanted deformations such as bending during heat treatment. If the structure must be slightly deformed during assembly to meet the demand for geometrical tolerances, thin integral bridge sections may also cause strength problems, particularly during assembly.

It is generally desirable to provide a rotor for a modulating magnetic pole which is relatively inexpensive to manufacture and assemble. It is further desirable to provide such rotors with good performance parameters such as high structural stability, low magnetoresistance, efficient magnetic flux path guidance low weight and inertia, and the like.

According to a first aspect, an embodiment of a rotor for a modulating pole is disclosed herein, wherein the rotor is configured to generate a rotor magnetic field for interaction with the stator magnetic field of the stator of the modulation pole.

A tubular support structure defining a circumferential mounting surface, the tubular support structure comprising a plurality of elongate recesses in the mounting surface, the elongate recesses extending in the axial direction of the tubular support structure,

A plurality of permanent magnets magnetized in the circumferential direction of the rotor to generate a rotor magnetic field, the permanent magnet extending axially to direct the rotor magnetic field generated by the permanent magnet at least radially; A plurality of permanent magnets, separated from one another in the circumferential direction of the rotor by an electron pole section,

At least one permanent magnet or at least one rotor pole section extends at least partially radially into one of the plurality of recesses. Thus, at least one component selected from the permanent magnet and the rotor pole section at least partially extends into one of the plurality of recesses such that a portion of the component extends from the recess.

Thus, in the embodiment of the rotor described herein, the permanent magnet and the rotor pole section form a tubular rotor structure coaxial with the tubular support structure. One of the circumferential surfaces of the tubular rotor structure is connected to the circumferential mounting surface of the tubular support structure. To this end, some or all of the permanent magnets and / or some or all of the rotor pole sections protrude into each recess of the mounting surface of the tubular support structure radially from one of the circumferential surfaces of the tubular rotor structure. .

Embodiments of the rotors described herein are effective and reliable when well-defined air gaps are provided with relatively large tolerances on individual components, even when the components to be assembled have limited strength and brittle behavior. Provides an assembly process.

In some embodiments, at least one permanent magnet or at least one extending at least partially radially into one of the plurality of recesses so that the radial length of the portion extending from the recess can be adjusted. It is adapted to allow the position of the rotor pole section of to be adjusted radially.

The recess can be adapted to have a depth greater than the depth required for the average component so that the position of the component can be adjusted radially. Thereby, a component manufactured with a radial length greater than average can be inserted deeper into the recess as a result of manufacturing variation, so that the radial length of the portion extending from the recess can be that of the average component. To be. The opposite principle can be used for components manufactured with sub-average radial lengths.

In some embodiments of the invention, at least one permanent magnet or at least one rotor pole section extending at least partially into one of the plurality of recesses contacts two sidewalls of the recess, ie by adhesion Contact or separate from the two side walls.

The rotor may be any type of rotor, such as an inner rotor adapted to rotate radially inside the outer stator or an outer rotor adapted to rotate around the inner stator.

A plurality of permanent magnets may be arranged such that all second magnets around the circumference are inverted in the magnetization direction. Thereby, the rotor pole section can only interface with a magnet exhibiting the same polarity.

The recess may be periodically located along the mounting surface of the tubular support structure. The wall of the recess can extend radially into the tubular support structure. Thus, a permanent magnet or rotor pole section extending at least partially into one of the plurality of recesses may extend from the recess in the radial direction.

In some embodiments, the circumferential mounting surface is formed by the inner surface of the tubular support structure. This design is beneficial for external rotors.

In some embodiments, the circumferential mounting surface is formed by the outer surface of the tubular support structure. This design is advantageous for the internal rotor.

The tubular support structure may comprise any number of recesses, such as 2 to 200, 5 to 60, or 10 to 30. In some embodiments of the invention, all recesses have permanent magnet or rotor pole sections. The tubular support structure can have any axial length. In some embodiments of the invention, the axial length of the tubular support structure corresponds to the axial length of the permanent magnet and / or rotor pole section. In some embodiments of the invention, the recess extends along the entire axial length of the tubular support structure. In some embodiments of the invention, the recess extends along a limited portion of the axial length of the support structure. The recess may be formed by first and second parallel sidewalls extending radially into the tubular support structure connected by the third wall. In some embodiments of the invention, the third wall is perpendicular to the first and second walls. In some embodiments of the invention, the third wall is curved and has a curve approximately following the curvature of the tubular support structure. The rotor can have any size. The recess of the tubular support structure can be applied to allow the position of the rotor pole section or permanent magnet to be adjusted radially so that the radial length of the portion extending from the recess can be adjusted.

The rotor, for example the tubular support structure, may comprise means for transmitting the torque generated by the interaction between the rotor and the stator. In some embodiments, the tubular support structure is connected to the shaft to deliver the generated torque. For example, the surface of the tubular support structure opposite the mounting surface for mounting the magnet and / or the rotor pole section can be used for mounting the rotor on a hub, shaft, or the like.

The cost of manufacturing any product is closely related to the precision requirements of the final product. High precision manufacturing requires complex and expensive manufacturing techniques or relatively large reject rates of the manufactured product, both approaches resulting in high manufacturing costs. In order to ensure efficient interaction between the rotor and the stator of the modulation poles, high precision requirements are applied. This leads to corresponding high precision requirements for the components of the rotor, for example the rotor pole section and the permanent magnet. However, by supplying a rotor having a support structure comprising a plurality of recesses, the rotor pole section or permanent magnet can be adjusted radially into the recess of the tubular support structure, thereby extending radially from the recess. Allow the length of the part to be adjusted. This can reduce the precision requirements of the rotor section or permanent magnet, thereby correspondingly reducing the manufacturing cost. In some embodiments of the invention, the gap between the component located in the recess and the back side of the recess is filled with a suitable material, such as a suitable type of adhesive, such as an epoxy adhesive.

In some embodiments, the support structure may include a compact recess for axially transporting the adhesive during radial adjustment of the rotor pole pieces or permanent magnets in the recess. The compact recess can provide respective channels for the adhesive to axially escape the area under the pole piece or permanent magnet thereby improving the tolerance adjustment accuracy.

The tubular support structure can also function to simplify the assembly process of the rotor section by providing a frame into which the rotor pole section and the permanent magnet can be inserted. The tubular support structure can additionally function to provide a more rigid rotor, reducing the risk of tilting the rotor through use. Since the tubular support structure can be manufactured with great precision, the final rotor can have a reduced geometrical deviation, increasing the overall quality of the product and reducing the risk of human error. Thereby fewer rotors need to be discarded.

An advantage of the present invention is that having a recess in the tubular support structure allows the position of the permanent magnet or rotor pole section to be modified, and higher tolerances of the individual components can be handled, which also allows the It includes tolerances. Another disadvantage is that the tubular support structure provides a frame for easy and good concentric assembly of the rotor according to the invention.

In some embodiments, the tubular support structure may be a single component or may be provided, for example, as a plurality of segments or modules divided axially and / or circumferentially. Similarly, some or each of the permanent magnets and / or pole pieces may be modular, for example divided axially or otherwise divided into multiple components.

In some embodiments of the invention, the rotor pole section is made from a soft magnetic material, such as a soft magnetic powder. By manufacturing the rotor pole section from the soft magnetic powder, the manufacture of the rotor can be simplified and the magnetic flux concentration that takes advantage of the effective three-dimensional magnetic flux path can be more efficient.

In some embodiments of the present invention, the tubular support structure is made of nonmagnetic material and / or other suitable nonmagnetic material, such as aluminum, plastic, for example extruded aluminum, injection molded plastic, and the like. By making the tubular support structure from nonmagnetic material, the magnetic properties of the rotor are not disturbed.

According to a first aspect, a permanent magnet is fitted inside the recess of the tubular support structure, and the rotor pole section is disposed between two adjacent permanent magnets. By fitting a permanent magnet inside the recess of the support structure, the permanent magnet extends radially beyond the rotor pole section. This may allow more efficient use of the magnetic flux generated by the permanent magnets.

In some embodiments of the invention, the rotor pole section fits inside the recess of the support structure.

In some embodiments of the invention, the permanent magnet or rotor pole section is fitted inside the recess of the tubular support structure by a friction fit formed by the sidewalls of the recess. By using a friction fit, an easy and reliable method of securing a permanent magnet or rotor pole section is provided. The friction fit can be created by designing the recess to be smaller at night than the permanent magnet or rotor pole section. The adjustment of the friction force can be facilitated by the controlled deformation of the recess wall, for example by some integral design features such as the lip of the material which can be bent with a desired force small enough to prevent damaging the pole section or the magnet. .

According to a second aspect, the invention relates to a rotor pole section for a rotor as disclosed above, wherein the rotor pole section extends radially from the recess forming a radial axis when fitted within the recess. Rotor pole section,

A first constant width zone defining a first end of the rotor pole section configured to be at least partially fitted into a recess of the support structure, the first constant width zone being a rotor pole in the first constant width zone; A first constant width region, having two parallel sidewalls such that the width of the section is constant,

A taper zone starting at the point where the first constant width zone ends, the tapered zone comprising a tapered zone having two non-parallel sidewalls such that the width of the rotor pole section in the tapered zone is not constant .

Thus, the tapered regions of two adjacent rotor pole sections form slot openings with parallel walls for permanent magnets, thereby facilitating the simple and low cost geometry of expensive permanent magnets.

In some embodiments of the invention, the sidewalls of the first constant width region are parallel to the radial axis.

In some embodiments of the invention, the sidewalls of the tapered zone are not parallel to the radial axis.

For the purposes of the present description, the length of the rotor pole section is defined as the dimension extending along the radial axis of the tubular support structure when the rotor pole section is fitted in the tubular support structure, and the height of the rotor pole section is the rotor. The pole section is defined as a dimension extending along the axis of the tubular support structure when fitted to the tubular support structure, and the width of the rotor pole section is defined as a dimension perpendicular to the length and height of the rotor pole section.

The height of the rotor pole section may be constant through both the first constant width zone and the tapered zone. The length of the first constant width region may approximately correspond to the depth of the recess, for example the height (in the radial direction) of the sidewall of the recess. In some embodiments of the invention, the first constant width region corresponds to 2 to 30 percent of the total length of the rotor pole section. In some embodiments of the invention, the length of the first constant width region corresponds to 5 to 20 percent of the total length of the rotor pole section. In some embodiments of the invention, the length of the first constant width region corresponds to 8 to 12 percent of the total length of the rotor pole section.

The tapered zone can have any length. In some embodiments of the invention, the length of the tapered section corresponds to 40 to 95 percent of the total length of the rotor pole section. In some embodiments of the invention, the length of the tapered section corresponds to 60 to 90 percent of the total length of the rotor pole section. The length of the tapered zone can be determined by the radial length of the permanent magnet. In some embodiments of the invention, the two side walls of the tapered zone are straight walls angled toward the central radial axis so that the width of the rotor pole section is monotonically along the radial axis with increasing distance to the first constant width zone. This design is advantageous when the rotor pole section is used for an external rotor. In some embodiments of the invention, the two sidewalls of the tapered zone are straight walls angularly spaced from the central radial axis such that the width of the rotor pole section is along the radial axis with increasing distance to the first constant width zone. Monotonically increasing, this design is advantageous when the rotor pole section is used for the internal rotor.

In order to ensure the cylindrical shape of the rotor, in some embodiments of the invention, the rotor pole section preferably comprises a tapered section. As mentioned above, the tapered zone ensures that the width of the rotor pole section is expanded for the inner rotor and reduced for the outer rotor. However, by further having a first constant width zone adapted to be located in the recess of the tubular support structure, assembly of the rotor using the rotor pole section can be inserted into the recess when the rotor pole section is moved along the radial axis. Can be simplified. This appears to be superior to pressing the rotor pole sections in the recess using axial movement because the height of the rotor pole sections is typically large, making them unstable at the beginning of the insertion process. This can reduce manufacturing costs. The first constant width region also serves to ensure a tighter fit when the rotor pole section is used for the internal rotor.

In some embodiments of the invention, the rotor pole section further comprises a second constant width zone starting at the point where the taper zone ends and forming a second end of the rotor pole section. The sidewalls of are parallel to each other such that the width of the rotor pole section is constant within the second constant width region.

In some embodiments, the two side walls of the second constant width region are parallel to the radial axis.

The second constant width region may have any length. In some embodiments of the invention, the second constant width region has a length corresponding to 2-20 percent of the total length of the rotor pole section. In some embodiments of the invention, the second constant width region has a length corresponding to 5-15 percent of the total length of the rotor pole section.

By having a second constant width zone, the width of the space formed by two adjacent rotor pole sections can be reduced from the point where the second constant width zone begins. By this, the magnet disposed in the space can be prevented from falling out of the pocket in the radial direction.

In some embodiments of the invention, the height of the pole section is greater than the length and the length is greater than the width.

According to a third aspect, the present invention provides a method of manufacturing a rotor pole section as disclosed above and below using powder densification,

Obtaining a die having an inverse shape of the rotor pole section as disclosed above and below comprising a first constant width zone and a second constant width zone,

Filling the die with magnetic powder, for example iron or iron-based powder,

Compressing the deformable magnetic powder in the die using, for example, two or more punches,

At least one of the punches moves relative to the other punch along the radial axis of the final rotor pole section to partially enter at least one of the first constant width region or the second constant width region of the die, thereby providing a final rotor pole. A method of manufacturing a rotor pole section in which the length of at least one of the first constant width region or the second constant width region of the section is reduced during densification.

The magnetic powder may for example be a soft magnetic iron powder or a powder of an alloy containing Co or Ni or a portion thereof. The soft magnetic powder may be substantially pure water sprayed iron powder or sponge iron powder with irregularly shaped particles coated with an electrical insulator. In this context, the term "substantially pure" means that the powder can be substantially free of inclusions and the amounts of impurities O, C and N can be kept to a minimum. The average particle diameter is generally less than 300 μm and more than 10 μm.

However, as long as the soft magnetic properties are sufficient and the powder is suitable for die densification, any soft magnetic metal powder or metal alloy powder can be used.

The electrical insulator of the powder particles can be made of an inorganic material. Particularly suitable are the types of insulators disclosed in US Pat. No. 6,348,265 (incorporated herein by reference), which relates to particles of a base powder consisting essentially of pure iron with insulating oxygen and a phosphorus containing barrier. Powders with insulated particles are available as Somaloy (R) 500, Somaloy (R) 550 or Somaloy (R) 700 available from Hoeganas AB, Sweden.

In this regard, the rotor pole section is efficiently manufactured in the same operation by the use of a powder forming method where the molding takes place in a single densification tool set-up.

By having a constant width zone within the die, the punch can move to varying degrees within the zone without damaging the die. This allows for greater tolerance of the compressibility of iron powder, further reducing manufacturing costs.

According to a fourth aspect, the present invention relates to a method for manufacturing a rotor for a modulating polar instrument, said rotor comprising a tubular support structure defining a circumferential mounting surface, said tubular support structure being characterized by the support structure in the mounting surface. A plurality of elongate recesses periodically positioned along the mounting surface, the elongate recesses extending in the axial direction of the tubular support structure, each recess having two sidewalls, and the rotor from the soft magnetic material The method further comprises a plurality of permanent magnets circumferentially separated from each other by the manufactured axially extending rotor pole sections, the method further comprising

Disposing a permanent magnet or rotor pole section at least partially inside each recess, wherein the permanent magnet or rotor pole section extends radially from the recess and thereby allows a plurality of recesses between two adjacent recesses; A permanent magnet or rotor pole section placement step of forming a slot,

Placing a permanent magnet or rotor pole section inside each formed slot.

In some embodiments of the invention, the method further comprises disposing an airgap fixture concentric with the support structure, wherein the rotor pole section or permanent magnet is radially adjusted within the recess to face the airgap fixture. The side of the magnet or rotor pole section comes into contact with the air gap fixture.

The air gap fixture is preferably circular when assembling the outer rotor and tubular when assembling the inner rotor. The airgap fixture may have any axial length, such as an axial length that is approximately equal to the axial length of the support structure, an axial length that is lower than the support structure, or an axial length that exceeds the axial length of the support structure.

By using the air gap fixture, a fast and easy assembly method of the rotor according to the present invention is provided, which reduces manufacturing costs. Air gap fixtures can additionally be used in automated manufacturing processes, thereby further reducing manufacturing costs. The airgap fixture may likewise function to ensure small deviations in the final product.

In some embodiments of the invention, the airgap fixture further comprises a magnetic device for enhancing the contact pressure between the rotor pole section or permanent magnet and the airgap fixture.

The magnetic device is a magnetic flux circuit in which the pole piece or permanent magnet forms part of the magnetic circuit such that the magnetic force generated by the magnetic circuit can hold the pole piece and the permanent magnet in close proximity to the fixture representing the desired air gap geometry of the applicator. May be an array of. The magnetic circuit may comprise a magnetic field source, which may be an electromagnet using wires and coils having a controllable current to generate a magnetic field or by an external permanent magnet. The external permanent magnet may be a permanent magnet of the rotor. Additionally, there may be recesses extending radially axially in the surface of the magnetic fixture surface to further improve the geometry control of the rotor pole pieces and the permanent magnets during the assembly process.

By using an airgap fixture that includes a magnetic device, magnetic energy can be used to adjust the position of the rotor pole section, which may further reduce manufacturing costs.

According to a fifth aspect, the present invention relates to an electric rotating machine, the machine comprising: a first stator core section substantially circular and comprising a plurality of teeth, a second stator core section substantially circular and comprising a plurality of teeth And a coil arranged between the first and second circular stator core sections and a rotor as disclosed above and / or below, wherein the first stator core section, the second stator core section, the coil and the rotor have a common geometry. Enclose an axis, the plurality of teeth of the first stator core section and the second stator core section are arranged to protrude toward the rotor, the teeth of the second stator core section being circumferential with respect to the teeth of the first stator core section Is displaced.

Different aspects of the present invention respectively yield one or more of the benefits and advantages described in connection with at least one of the foregoing aspects and correspond to the preferred embodiments described in connection with at least one of the aspects disclosed in the foregoing and / or dependent claims. It can be implemented in different ways, including the rotor and rotor pole sections and additional product means described above and below, each having one or more preferred embodiments. Moreover, it will be understood that the embodiments described in connection with one of the aspects described herein may apply equally to the other aspects.

The above and / or additional objects, features and advantages of the present invention will become more apparent from the following illustrative, non-limiting detailed description of embodiments of the invention, with reference to the accompanying drawings.

1A shows an exploded perspective view of a conventional modulation pole,
1b shows a cross-sectional view of a conventional modulation pole,
2A illustrates a tubular support structure of an outer rotor in accordance with some embodiments of the present invention,
2B shows a more detailed view of the recess of the external rotor in accordance with some embodiments of the present invention,
2C illustrates a tubular support structure including a plurality of permanent magnets 203 of an external rotor, in accordance with some embodiments of the present invention,
2D illustrates an external rotor in accordance with some embodiments of the invention,
3 illustrates an internal rotor in accordance with some embodiments of the invention,
4 illustrates a rotor pole section 401 for an external rotor, in accordance with some embodiments of the present invention,
5 illustrates a method for manufacturing the rotor pole section 502 in accordance with some embodiments of the invention,
6A illustrates an external rotor in accordance with some embodiments of the present invention,
6B shows a more detailed view of a portion of an external rotor, in accordance with some embodiments of the present invention,
7A illustrates a rotor in accordance with some embodiments of the present invention,
7B shows a more detailed view of a rotor in accordance with some embodiments of the present invention,
8A and 8B show examples of magnetic air-gap fixture devices,
FIG. 9 shows an example of a modulation pole, in particular FIG. 9A shows a perspective view of an active part of a machine comprising a stator 10 and a rotor 30, and FIG. 9B shows an enlarged view of a part of the machine. ,
FIG. 10 shows an example of the stator 10 of the modulation pole of FIG. 9,
FIG. 11 shows an example of a three phase modulation pole, in particular FIG. 11A shows an active part of an example of a three phase modulation pole, and FIG. 11B shows an example of a stator of the machine of FIG. 11A.

In the following description, reference is made to the accompanying drawings that show, by way of illustration, how the invention may be practiced.

The present invention is in the field of modulated electric poles 100, one example of which is shown in FIG. 1A in a schematic exploded perspective view. The modulated electric pole stator 10 is basically characterized by the use of a central single winding 20 capable of magnetically feeding a plurality of teeth 102 formed by a soft magnetic core structure. The stator core is then formed around the windings 20, while for other common electrical mechanical structures the windings are formed around individual tooth core sections. Examples of modulated polar morphology are often recognized, for example, as claws, crow-fits, Lundel machines or TFM machines. More specifically, the modulated electron pole 100 shown depicts two stator core sections 14, 16 that are each substantially circular and include a plurality of teeth 102, and first and second circular stator core sections. And a rotor 30 including a coil 20 arranged therebetween and a plurality of permanent magnets 22. In addition, the stator core sections 14, 16, coil 20 and rotor 30 enclose a common geometric axis 103, and the plurality of teeth of the two stator core sections 14, 16 have a closed circuit magnetic flux. It is arranged to protrude toward the rotor 30 to form a path. The machine of figure 1 is of radial type because the stator teeth project radially towards the rotor and in this case the stator surrounds the rotor. However, the stator may equally well be arranged internally with respect to the rotor, which type is also shown in some of the figures below. The scope of the present invention as set out below is not limited to any particular type of modulated electronic pole, but internally and externally arranged stators for both axial and radial machines and rotors Equally well for all of Similarly, the present invention is not limited to a single phase machine but equally well applicable to a multiphase machine.

The active rotor structure 30 is composed of the same number of segments 22, 24, while half of the number of segments, also called rotor pole sections 24, is made of soft magnetic material and differs from the number of segments. Half is made of permanent magnet material 22. State of the art is to make these segments as individual components. Often, the number of segments can be rather large, typically between 10 and 50 individual sections. The permanent magnets 22 are arranged such that the magnetization direction of the permanent magnets is substantially circumferential, that is, the N pole and the S pole are each oriented substantially in the circumferential direction. Further, all the second permanent magnets 22 counted in the circumferential direction are arranged with their magnetization directions in opposite directions with respect to the other permanent magnets. The functionality of the soft magnetic pole section 24 in the desired mechanical structure is completely three-dimensional, and it may be possible for the soft magnetic pole section 24 to have a variable magnetic flux with high permeability in all three spatial directions. Traditional designs using laminated steel sheets advantageously use soft magnetic structures and materials that do not exhibit the required high permeability in a direction perpendicular to the plane of the steel sheet and which exhibit higher magnetic flux isotropy than state of the art laminated steel sheets.

FIG. 1B shows the same radial modulation electronic polarity as from FIG. 1, but how the stator teeth 102 extend toward the rotor and how the stator teeth of the two stator core sections 14, 16 relate to each other It is shown in a cross sectional view of the assembled machine which more clearly shows whether it is displaced rotationally.

In the following, an example of a rotor that can be used as part of the modulated electric pole shown in FIGS. 1A and 1B will be described in more detail. It is to be understood that the rotor described in this application can be used with stators of different types of modulation poles than described above.

2A illustrates a tubular support structure 201 of an external rotor in accordance with some embodiments of the present invention. The tubular support structure 201 has a radius and a height, the height extending along the axis of the tubular support structure 201. The tubular support structure 201 includes a plurality of recesses 202 periodically positioned around the periphery of the support structure 201 in the circumferential mounting surface, which is an inner surface of the tubular support structure 201. The tubular support structure 201 may be made of an impermeable material such as, for example, a nonmagnetic material such as aluminum or plastic. A plurality of recesses 202 extend in the axial direction of the tubular support structure. 2b shows a more detailed view of the recess. The recess includes two parallel sidewalls 205, 206 extending radially into the tubular support structure. Two parallel sidewalls 205, 206 are connected by end walls 207. The recess extends through the entire height of the tubular support structure 201.

2C illustrates a tubular support structure including a plurality of permanent magnets 203 of an external rotor in accordance with some embodiments of the present invention. Each of the plurality of recesses includes a permanent magnet 203. The permanent magnet 203 may be secured in the recess 202 by any kind of fastening means, such as a friction fit and / or a suitable type of adhesive.

2D illustrates an external rotor in accordance with some embodiments of the present invention. The outer rotor includes a tubular support structure 201, a plurality of permanent magnets 203, and a plurality of rotor pole sections 204. The rotor pole section 204 fits into a slot formed by a permanent magnet fitted inside the recess 202 of the support structure 201. The rotor pole section 204 may be fastened to the permanent magnet and / or support structure by a friction fit formed by a permanent magnet and / or any type of fastening means, for example a suitable type of adhesive. As the permanent magnets 203 fit into the recesses 202 of the support structure 201, they extend radially outwardly more than the rotor pole section 204. By this, more of the magnetic field generated by the permanent magnet 203 can be used by the pole section to generate the rotor magnetic field. This can reduce the magnetic requirements of the permanent magnets, so that smaller permanent magnets can be used, thereby reducing the manufacturing cost. FIG. 3 shows the inner rotor corresponding to the outer rotor shown in FIG. 2D.

4 illustrates a rotor pole section 401 for an external rotor in accordance with some embodiments of the present invention. Rotor pole section 401 has a width 407 and a length 406. Rotor pole section 401 includes three zones: a first constant width region 402, a tapered region 403, and a second constant width region 404. The first constant width region 402 is adapted to fit at least partially within the recess of the support structure. The first constant width region 402 includes two sidewalls parallel to the radial axis of the rotor pole section 401, whereby the width of the rotor pole section 401 is defined by the first constant width region 402. To ensure that it is constant within. The length of the first constant width region may correspond approximately to the depth of the recess, for example the range of the two sidewalls of the recess. The tapered zone 403 includes two straight sidewalls that are identical in relation to the radial axis of the rotor pole section 401 but with opposite angles so that the width of the tapered zone increases to the first constant width zone 402. It decreases monotonically with distance. However, in another embodiment, the sidewalls of the tapered zone are mirror imaged such that the rotor pole section of the tapered zone monotonically increases with increasing distance to the first constant width zone 402. The second constant width region 404 includes two sidewalls parallel to the radial axis of the rotor pole section 401, whereby the width of the rotor pole section 401 is constant in the second constant width region. To ensure. The second constant width region may further include a concave end 405 when the rotor pole section is used for the outer rotor and a convex end when the rotor pole section is used for the inner rotor. In some embodiments of the invention, the rotor pole section includes only the first constant width region 402 and the tapered region 403.

5 illustrates a method of manufacturing the rotor pole section 502 in accordance with some embodiments of the present invention. The rotor pole section 502 is made by filling the die 501 with iron or iron-based powder and by compressing the iron powder with two punches 505, 506. The die 501 has the difference that the lengths of the first and second constant width zones 503, 504 of the die 501 extend, and, for example, of the desired rotor pole section as shown in FIG. 4. Have an inverted shape. This allows the punches 505, 506 to be moved in the radial direction of the final rotor pole section 502, partially entering the first and second constant width zones 503, 504 of the die 501, This compresses the iron powder in die 501 to form rotor pole section 502.

6A illustrates an external rotor in accordance with some embodiments of the present invention. The outer rotor includes a tubular support structure 601, a plurality of permanent magnets 603, and a plurality of rotor pole sections 604, as shown in FIG. 4. The tubular support structure includes a plurality of recesses 602 periodically positioned around the perimeter of the support structure 601. The rotor pole section 604 fits into a plurality of recesses 602 of the tubular support structure 601, and the permanent magnet 603 fits into a slot formed by two adjacent rotor pole sections 604.

FIG. 6B shows a more detailed view of the portion of the external rotor shown in FIG. 6A. FIG. 6B shows how the shape of the rotor pole section 604 fitted in the recess 602 of the tubular support structure 601 affects the space formed by two adjacent rotor pole sections 604. . Taper zone 607 of rotor pole section 604 ensures that the width of the space formed between two adjacent rotor pole sections 604 is constant along the taper zone of rotor pole section 204. This allows the permanent magnet 605 having a constant width to fit in the space. By providing a second constant width zone 608 to the rotor pole section 604, the width of the space formed between two adjacent rotor pole sections 604 is equal to the second constant width zone of the rotor pole section 604. Is reduced along 608. This ensures that the permanent magnet 603 surrounded in the space slides radially from the rotor.

7A illustrates a rotor in accordance with some embodiments of the present invention further including an airgap fixture 605. The air gap fixture can ensure accurate positioning of the rotor pole section during manufacture of the rotor. The airgap fixture 605 may have a cylindrical shape or alternatively a conical shape when assembling the outer rotor and a tubular shape when assembling the inner rotor. Airgap fixture 605 may be used to adjust rotor pole section 604 radially within recess 602. The airgap fixture may include a magnetic device that allows magnetic energy to be used to adjust the radial position of the rotor pole section 604 in the recess 602. After assembling the rotor, the air gap fixture can be removed. FIG. 7B shows a more detailed view of FIG. 7A. By using the air gap fixture, a fast and easy assembly method of the rotor according to the present invention is provided, which reduces manufacturing costs.

8A and 8B show examples of magnetic airgap fixture devices. The magnetic airgap fixture 605 has a generally cylindrical body having a circumferential recess 851 for receiving a coil 852 to provide a controllable magnetic field to hold the rotor pole section 853 in place. Include.

9 shows an example of a modulation pole. In particular, FIG. 9 shows a phase of an active portion of a single phase, for example a single phase machine or a multiphase machine. 9A shows a perspective view of an active part of a machine including a stator 10 and a rotor 30. 9b shows an enlarged view of a part of the machine.

FIG. 10 shows an example of the stator 10 of the modulation pole of FIG. 9. In particular, FIG. 10 shows a cutaway view of the stator 10.

The machine includes a stator 10 that includes a central single winding 20 that magnetically feeds a plurality of teeth 102 formed by a soft magnetic core structure. The stator core is formed around the windings 20, while for other common electric mechanical structures the windings are formed around individual tooth core sections. More specifically, the modulating electrical poles of FIGS. 9 and 10 include two stator core sections 14, 16 that are each annular and substantially annular, and first and second annular stator core sections. And a rotor 30 comprising a winding 20 arranged therebetween and a plurality of permanent magnets 22. In addition, the stator core sections 14, 16, coil 20, and rotor 30 enclose a common geometric axis, and the plurality of teeth 102 of the two stator core sections 14, 16 are closed circuit magnetic fluxes. It is arranged to protrude toward the rotor 30 to form a path. The stator teeth of the two stator core sections 14, 16 are circumferentially displaced with respect to each other.

Each stator section includes an annular core back surface 261 that provides a circumferential flux path between neighboring teeth. The stator further comprises a flux bridge or yoke component 18 that provides at least an axial flux path between the two stator core sections. In the machine of FIGS. 9 and 10, the stator teeth project radially towards the rotor, in which case the rotor surrounds the stator. However, the stator may be equally well positioned externally to the rotor. Embodiments of the rotors described herein can be used in single phase and / or multiphase machines.

The active rotor structure 30 is constructed from the same number of segments 22, 24, and half of the number of segments, also referred to as rotor pole section 24, is made of soft magnetic material and the number of segments The other half is made of permanent magnet material 22. These segments can be manufactured as individual components. For purposes of illustration only the magnetic active portion of the rotor is shown in FIGS. 9 to 10. The tubular support structure described herein is not explicitly shown in FIGS. 9-10.

The permanent magnets 22 are arranged such that the magnetization direction of the permanent magnets is substantially circumferential, that is, the N poles and the S poles each face substantially circumferentially. Further, all the second permanent magnets 22 counted in the circumferential direction are arranged with their magnetization directions in opposite directions with respect to their neighboring permanent magnets. The functionality of the soft magnetic pole section 24 in the desired mechanical structure is completely three dimensional, and each soft magnetic pole section 24 may be capable of effectively having a variable magnetic flux with high permeability in all three spatial directions.

This design of the rotor 30 and the stator 10 allows the total magnetic flux from the surfaces of the facing permanent teeth 22 to the surface of the facing teeth of the rotor 30 facing the teeth of the stator 10 from all of the neighboring permanent magnets 22. It has the advantage of enabling magnetic flux concentration from the permanent magnet 22 so that it can be presented. The flux concentration can be seen as a function of the area of the permanent magnets 22 facing each pole section 24 divided into areas facing the teeth. In particular, due to the circumferential displacement of the teeth, the teeth facing the pole section create an active air gap that only partially extends across the axial range of the pole section. Nevertheless, the magnetic flux from the full axial range of the permanent magnet is directed axially and radially within the pole section towards the active air gap. These magnetic flux concentration characteristics of each pole section 24 make it possible to use weak, low cost permanent magnets as permanent magnets 22 in the rotor, and to achieve very high air gap magnetic flux densities. The magnetic flux concentration can be facilitated by the pole section made from magnetic powder which enables an effective three dimensional magnetic flux path. In addition, the design also enables more efficient use of the magnet than in corresponding types of machines.

With continued reference to FIGS. 9 and 10, the single phase stator 10 is a stator of a single phase machine as shown in FIGS. 9 and 10 and / or for example the stator phases 10a to 10c of the machine of FIG. 11. Can be used as the stator phase of a multiphase machine such as Stator 10 includes two identical stator core sections 14, 16 each comprising a plurality of teeth 102. Each stator core section is made of soft magnetic powder that is densified to be molded in a press tool. When the stator core sections have the same shape, they can be pressed in the same tool. The two stator core sections are then joined in a second operation and form a stator core with radially extending stator core teeth, wherein the teeth of one stator core section are axial with respect to the teeth of the other stator core section. Direction and circumferentially.

Each stator core section 14, 16 can be compacted into a single part. Each stator core section 14, 16 may be formed as an annular disk having a central substantially circular opening formed by the radially inner edge 551 of the annular core backside 261. Teeth 102 protrude radially outward from the radially outer edge of the annular disc-shaped back surface. The annulus between the inner edge 551 and the teeth 102 provides radial and circumferential flux paths and sidewalls of the circumferential cavity that houses the coil 20. Each stator core section includes a circumferential flange 18 at or near the inner edge 551. In the assembled stator, the circumferential flange 18 is arranged on the inner surface of the stator core section, ie the side facing the coil 20 and the other core section. In the embodiment shown in FIGS. 9 and 10, the stator core sections 14, 16 are formed as the same component. In particular, both stator core sections include flanges 18 that project toward each other stator core section. In the assembled stator, the flanges 18 form an axial flux bridge that abuts each other and allows the provision of an axial flux path between the stator core sections. In the assembled stator for the external rotor machine, the coil thus encloses the stator core back surface formed by the flange 18. Each tooth 102 has an interface 262 facing the air gap. During operation of the machine, the magnetic flux communicates through the interface 262 via the air gap and through the corresponding interface of the pole pieces of the rotor.

FIG. 11A shows an active part of an example of a three-phase modulation polarizer, and FIG. 11B shows an example of a stator of the machine of FIG. 11A. The machine includes a stator 10 and a rotor 30. Stator 10 includes three stator phase sections 10a, 10b, 10c, respectively, as described in connection with FIGS. 9 and 10. In particular, each stator phase section includes a respective pair of stator components 14a, 16a; 14b, 16b; 14c, 16c, each holding one circumferential wing 20a-20c, respectively.

Thus, as in the examples of FIGS. 9 and 10, each modulated electrical pole stator phase section 10a-10c of FIG. 11 magnetically feeds a number of teeth 102 formed by a soft magnetic core structure. For example, it comprises central coils 20a to 20c, such as a single winding. More specifically, each stator phase 10a-10c of the modulated electrical pole 100 shown includes two stator core sections 14, a first, each of which comprises a plurality of teeth 102 and is substantially annular. And a coil 20 arranged between the second circular stator core sections. In addition, the stator core section 14 and the coil 20 on each stator surround a common axis, and the plurality of teeth 102 of the stator core section 14 are arranged to project radially outward. In the example of FIG. 11, the rotor 30 is arranged coaxially with the stator 10 and surrounds the stator to form an air gap between the stator and the teeth 102 of the rotor. The rotor may be provided as an alternating permanent magnet 22 and pole piece 24 as described in connection with FIGS. 9 and 10, but extends across all stator phase sections.

While some embodiments have been described and illustrated in detail, the invention is not limited thereto and may also be practiced in other ways within the scope of the subject matter defined in the following claims. In particular, it should be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention.

Embodiments of the invention disclosed herein may be used for direct wheel drive motors for electric bicycles or other electrically driven vehicles, in particular light vehicles. Such applications may place demands on high torque, relatively low speed and low cost. These needs can be met by motors with relatively high pole numbers of compact geometry using small-volume permanent magnets and wire coils to meet or meet cost requirements by improved rotor assembly routines.

In the device claim enumerating several means, several of these means may be embodied by one and the same hardware item. The fact that only certain means are cited in different dependent claims or described in different embodiments does not indicate that these means cannot be used to advantage.

The term "comprising / comprising", when used herein, is taken to describe the presence of a stated feature, integral, step, or component, but the presence of one or more other features, components, steps, components, or groups thereof. It should be emphasized that or does not exclude the addition.

Claims (19)

A rotor for modulating poles, wherein the rotor is configured to generate a rotor magnetic field for interaction with a stator magnetic field of the stator of the modulation poles,
A tubular support structure defining a circumferential mounting surface, said tubular support structure comprising a plurality of elongate recesses in said mounting surface, said elongate recesses extending in the axial direction of said tubular support structure. Support structure,
A plurality of permanent magnets magnetized in the circumferential direction of the rotor to generate a rotor magnetic field, the permanent magnets extending axially to direct the rotor magnetic field generated by the permanent magnet at least radially; Separated from each other in the circumferential direction of the rotor by a rotor pole section, the permanent magnet extending at least partially radially into each one of the plurality of recesses, each rotor pole section having two adjacent A plurality of permanent magnets, disposed between the permanent magnets,
Rotor.
The method of claim 1,
The plurality of recesses are adapted to allow the position of the permanent magnets to be adjusted radially so that the radial length of the portion of each permanent magnet extending from the recess can be adjusted;
Rotor.
The method according to claim 1 or 2,
Each permanent magnet is in contact with the two sidewalls of the recess,
Rotor.
The method according to any one of claims 1 to 3,
Wherein the permanent magnet is fitted inside the recess of the tubular support structure by a friction fit formed by the sidewalls of the recess
Rotor.
A rotor for modulating poles, wherein the rotor is configured to generate a rotor magnetic field for interaction with a stator magnetic field of the stator of the modulation poles,
A tubular support structure defining a circumferential mounting surface, said tubular support structure comprising a plurality of elongate recesses in said mounting surface, said elongate recesses extending in the axial direction of said tubular support structure. Support structure,
A plurality of permanent magnets magnetized in the circumferential direction of the rotor to generate a rotor magnetic field, the permanent magnets extending axially to direct at least radially the rotor magnetic field generated by the permanent magnets; A rotor pole section separated from each other in the circumferential direction of the rotor, at least one rotor pole section extending radially at least partially into one of a plurality of recesses, the rotor pole section being the support structure And a plurality of permanent magnets extending radially from the recess, which when formed in a recess of, form a radial axis,
The rotor pole section,
A first constant width zone defining a first end of the rotor pole section configured to be at least partially fitted into a recess of the support structure, the first constant width zone being a rotor pole in the first constant width zone; A first constant width region, having two parallel sidewalls such that the width of the section is constant,
A taper zone starting at the point where the first constant width zone ends, the tapered zone having a tapered zone having two non-parallel side walls which ensure that the width of the rotor pole section in the tapered zone is not constant doing,
Rotor.
The method of claim 5, wherein
The rotor pole section further comprising a second constant width zone starting at the point where the tapered zone ends and forming a second end of the rotor pole section, the sidewalls of the second constant width zone being parallel, Wherein the width of the rotor pole section is constant within the second constant width region,
Rotor.
The method according to claim 5 or 6,
The plurality of recesses is adapted to enable radial adjustment of the position of the rotor pole section so that the radial length of the portion of each rotor pole section extending from the recess can be adjusted;
Rotor.
8. The method according to any one of claims 5 to 7,
Wherein the rotor pole section is fitted inside the recess of the tubular support structure by a friction fit defined by the side wall of the recess.
Rotor.
The method according to any one of claims 1 to 8,
The circumferential mounting surface is an inner surface of the tubular support structure,
Rotor.
10. The method according to any one of claims 1 to 9,
The circumferential mounting surface is an outer surface of the tubular support structure,
Rotor.
11. The method according to any one of claims 1 to 10,
The rotor pole section is made from a soft magnetic material,
Rotor.
12. The method according to any one of claims 1 to 11,
The tubular support structure is made of a nonmagnetic material such as aluminum or plastic,
Rotor.
In the rotor pole section,
A first constant width region forming a first end of the rotor pole section, adapted to at least partially fit in a recess of the support structure, the first constant width zone being a rotor pole in the first constant width zone; A first constant width region having two parallel sidewalls such that the width of the section is constant,
A taper zone starting at the point where the first constant width zone ends, the tapered zone comprising a tapered zone having two non-parallel sidewalls such that the width of the rotor pole section in the tapered zone is not constant ,
Rotor pole section.
The method of claim 13,
The rotor pole section further comprising a second constant width region starting at the point where the taper zone ends and forming a second end of the rotor pole section, the sidewalls of the second constant width region being parallel, Wherein the width of the rotor pole section is constant in the second constant width region,
Rotor pole section.
A method for producing a rotor pole section according to claim 13 or 14 using powder densification,
Obtaining a die having an inverse shape of the rotor pole section comprising a first constant width region and a second constant width region,
Filling the die with magnetic powder,
Compressing magnetic powder in the die using at least two punches,
At least one of the punches moves relative to the other punch along the radial axis of the final rotor pole section to partially enter at least one of the first constant width region or the second constant width region of the die, thereby providing the final The length of at least one of the first constant width region or the second constant width region of the rotor pole section is reduced,
How to manufacture the rotor pole section.
A method for manufacturing a rotor for modulating poles, the rotor comprising a tubular support structure defining a circumferential mounting surface, the tubular support structure being a plurality of periodically located along the mounting surface of the support structure in the mounting surface. An elongate recess of which the axial recess extends in the axial direction of the tubular support structure, each recess having two sidewalls, and the rotor extending in an axial direction made from a soft magnetic material A method for manufacturing a rotor for a modulating polar instrument, the method further comprising a plurality of permanent magnets circumferentially separated from each other by a rotor pole section.
Disposing a permanent magnet or rotor pole section at least partially inside each recess, wherein the permanent magnet or rotor pole section extends radially from the recess and thereby has a plurality between two adjacent recesses; A permanent magnet or rotor pole section placement step, forming a slot of the,
Disposing a permanent magnet or rotor pole section inside each formed slot,
Method for manufacturing a rotor for modulating polar instrument.
17. The method of claim 16,
Disposing an airgap fixture concentric with the support structure, wherein the rotor pole section or permanent magnet is radially adjusted within the recess to the side of the permanent magnet or rotor pole section facing the airgap fixture. In contact with the air gap fixture,
Method for manufacturing a rotor for modulating polar instrument.
The method of claim 17,
The air gap fixture further comprises a magnetic device for enhancing the contact pressure between the rotor pole section or the permanent magnet and the air gap fixture,
Method for manufacturing a rotor for modulating polar instrument.
13. A modulation pole comprising a rotor and a stator according to any one of claims 1-12.
The stator is
First and second stator core sections each comprising a plurality of teeth projecting radially towards the rotor,
A winding arranged between said first and second stator core sections,
The teeth of the second stator core section are circumferentially displaced relative to the teeth of the first stator core section, and the axially extending rotor pole sections separating the permanent magnets comprise first and second stator core sections. Extends axially to all of
The magnetization direction of the permanent magnet of the rotor allows the flux path generated in the axially extending pole section during use of the modulating poles to extend at least in the circumferential and axial directions and from the facing area of the adjacent permanent magnet Substantially circumferential in order to be able to concentrate the magnetic flux to the position of the teeth of one of the sections, the magnetization directions of all the second permanent magnets opposing the magnetization directions of the permanent magnets therebetween,
Modulated polarity.

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