JP2013515455A - Rotor for modulating pole machine - Google Patents

Abstract

  A rotor for a modulating pole machine, wherein the rotor is configured to generate a rotor magnetic field for interacting with the stator magnetic field of the stator of the modulating pole machine, defining a circumferential mounting surface Tubular support structures 201, 301 having a plurality of elongated recesses 202 extending in the axial direction of the tubular support structure on the mounting surface, and disposed on the mounting surface of the tubular support structure, and a rotor magnetic field A plurality of permanent magnets 203 magnetized in the circumferential direction of the rotor so as to generate a radial direction of the rotor magnetic field generated by the permanent magnets. Are separated from each other in the circumferential direction of the rotor by an axially extending rotor pole area 204 and at least one permanent magnet 203 or one rotor pole area 204 is in one of the plurality of recesses. At least partially extends and the rotor.

Description

  The present invention relates to a rotor for a modulation pole machine, and more particularly to a rotor for a modulation pole machine that can be easily mass-produced.

  Over the years, there has been an increasing interest in electromechanical designs such as modulated pole machines, claw-pole machines, Lundell machines, and transverse flux machines (TFMs). An electrical machine using these mechanical principles was disclosed around 1910 by Alexandersson and Fessenden. One of the most important reasons of increasing interest is that this design allows very high torque output compared to, for example, induction machines, switched reluctance machines, and even permanent magnet brushless machines. Furthermore, such a machine is advantageous in that the coil is often easy to manufacture. However, one of the disadvantages of this design is that they are typically relatively expensive to manufacture, and they are subject to high leakage flux, resulting in low power factor and requiring more magnetic material. It is to become. The low power factor requires large power electronics (or a power supply when the machine is used synchronously), which also increases the volume, weight, and cost of the entire drive mechanism.

  The stator of a modulating pole electric machine is basically characterized by the use of a single center winding that provides magnetic force to the teeth formed by the soft magnetic core structure. Here, the soft magnetic core is formed around the winding. In contrast, in other common electromechanical structures, the windings are formed around the tooth core area. Examples of modulated pole machine topologies are sometimes recognized as, for example, claw pole machines, Crow-feet machines, Landell machines, or TFM machines. A modulated pole machine having an embedded magnet is further characterized by an active rotor structure that includes a plurality of permanent magnets separated by a rotor pole area. The active rotor structure is composed of an even number of segments, half of the segments are formed from a soft magnetic material and the remaining half of the segments are formed from a permanent magnet material. The permanent magnets are arranged such that the magnetization direction of the permanent magnets is substantially circumferential, that is, the north and south poles are substantially oriented in the circumferential direction, respectively.

  Traditionally, rotors are manufactured by making a relatively large number of individual rotor segments, typically 10-50. However, the assembly process is complex and time consuming because many components should be combined to obtain a well-defined air gap to maintain machine performance. In addition, the assembly process is complicated by the reverse polarity direction of the permanent magnet segments that tend to repel the rotor pole areas against each other during assembly.

  WO2009116935 discloses a rotor and a method for manufacturing a rotor in which the number of individual parts is reduced, thereby reducing the time required to assemble the rotor. However, this approach increases the complexity and cost of the individual parts. In addition, components can exhibit large variations in cross-sectional area, which can lead to undesirable deformations such as curvature during heat treatment, which can make it difficult to achieve good overall tolerances. Also, the integrated thin bridge area can cause strength problems during assembly, especially if the structure must be slightly deformed during assembly to meet the requirements for geometric tolerances.

International Publication No. 200916935 US Pat. No. 634,265

  In general, it is desirable to provide a rotor for a modulation pole machine that is relatively inexpensive to manufacture and assemble. It is further desired to provide a rotor with good performance parameters such as high structural stability, low reluctance, efficient flux path guidance, light weight, and low inertia.

In this specification, according to a first aspect, a rotor for a modulation pole machine is configured to generate a rotor magnetic field for interacting with a stator magnetic field of a stator of the modulation pole machine. In the rotor
A tubular support structure defining a circumferential mounting surface, wherein the mounting surface has a plurality of elongated 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, extending axially to direct the rotor magnetic field generated by the permanent magnet in a radial direction A plurality of permanent magnets separated from each other in the circumferential direction of the rotor by a rotor pole area;
An embodiment of a rotor is disclosed in which at least one permanent magnet or at least one rotor pole area extends at least partially radially into one of the plurality of recesses. Accordingly, at least one component selected from the permanent magnet and the rotor pole area extends at least partially into one of the plurality of recesses such that a portion of the component extends out of the recess. .

  As a result, in the rotor embodiment described herein, the permanent magnet and rotor pole area form a tubular rotor structure that is 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. For this purpose, some or all of the permanent magnets and / or some or all of the rotor magnetic pole areas are separated from the one of the circumferential surfaces of the tubular rotor structure by each of the mounting surfaces of the tubular support structure. Projecting radially into the recess.

  The rotor embodiments described herein provide an efficient and reliable assembly process, even when the individual component tolerances are relatively large, and even the strength and fragility of the components to be assembled. A well-defined air gap is provided even when the behavior is limited.

  In some embodiments, the plurality of recesses can radially adjust a position of at least one permanent magnet or at least one rotor pole area that extends at least partially into one of the plurality of recesses in the radial direction. So that the radial length of the portion extending out of the recess can be adjusted.

  The recess may be adapted to allow radial adjustment of the position of the component by having a depth greater than that required for the average component. This allows components made with radial lengths greater than the average due to manufacturing variations to be inserted deeper into the recesses and the average radial length of the portion extending out of the recesses Can be equal to that of the element. The reverse principle can be used for components made with radial lengths less than average.

  In some embodiments of the present invention, at least one permanent magnet or at least one rotor pole area extending at least partially into one of the plurality of recesses is in contact with the two sidewalls of the recess, ie 2 Either in direct contact with one side wall or separated from the two side walls by an adhesive.

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

  The plurality of permanent magnets can be arranged so that the magnetization direction of every other magnet is reversed around the circumference. Thereby, the individual rotor pole areas may only interfere with magnets showing the same polarity.

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

  In some embodiments, the circumferential mounting surface is defined by the inner surface of the tubular support structure. This design is beneficial for the outer rotor.

  In some embodiments, the circumferential mounting surface is defined by the outer surface of the tubular support structure. This design is beneficial for the inner rotor.

  The tubular support structure can comprise any number of recesses, such as between 2 and 200, between 5 and 60, or between 10 and 30. In some embodiments of the invention, permanent magnets or rotor pole areas are fitted in all recesses. The tubular support structure can have any axial length. In some embodiments of the present invention, the axial length of the tubular support structure corresponds to the axial length of the permanent magnet and / or rotor pole area. 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 only a portion of the axial length of the support structure. The recess can be formed by connecting first and second parallel side walls extending radially in the tubular support structure by a third wall. In some embodiments of the invention, the third wall is perpendicular to the first and second walls. In some embodiments of the present invention, the third wall is curved and has a curved shape that generally follows the curvature of the tubular support structure. The rotor can have any size. The recess in the tubular support structure can be adapted to allow radial adjustment of the rotor pole area or permanent magnet position, thereby adjusting the radial length of the portion extending out of the recess. It is made like that.

  A rotor, such as a tubular support structure, may comprise means for transmitting torque generated by the rotor-stator interaction. In some embodiments, the tubular support structure is connected to a shaft for transmitting the generated torque. For example, the surface of the tubular support structure that faces the mounting surface for mounting the magnet and / or rotor pole area can be used to mount the rotor to a hub, shaft, or the like.

  The cost of manufacturing any product is closely related to the accuracy requirements of the final product. High-precision manufacturing requires complex and expensive manufacturing techniques, or a relatively high defect rate of the manufactured product is unavoidable, either resulting in high manufacturing costs. High accuracy requirements are applied to ensure efficient interaction between the rotor and stator of the modulating pole machine. This creates corresponding high accuracy requirements for the rotor components, such as the rotor pole area and the permanent magnet. However, by providing the rotor with a support structure comprising a plurality of recesses, the rotor pole area or permanent magnet can be adjusted radially into the recesses of the tubular support structure, thereby providing a radius from the recesses. The length of the portion extending in the direction can be adjusted. This reduces the accuracy requirements of the rotor pole area or permanent magnet and thus correspondingly reduces manufacturing costs. In some embodiments of the invention, the gap between the component positioned in the recess and the back of the recess is filled with a suitable material, for example, a suitable type of adhesive, such as an epoxy adhesive.

  In some embodiments, the support structure may include a small recess for axial transport of adhesive during radial adjustment of the rotor pole piece or permanent magnet in the recess. These small recesses can provide a respective channel for the adhesive to escape axially from the area under the pole piece or permanent magnet, thereby increasing tolerance adjustment accuracy.

  The tubular support structure may also serve to simplify the assembly process of the rotor portion by providing a frame into which the rotor pole area and permanent magnet can be inserted. Further, the tubular support structure serves to provide a stiffer rotor, reducing the risk of rotor distortion during use. Because the tubular support structure can be manufactured with high precision, the resulting rotor geometrical variation is reduced, which increases the overall quality of the product and reduces the risk of human error. Thereby, fewer rotors need to be discarded.

  An advantage of the present invention is that by having a recess in the tubular support structure, the position of the permanent magnet or rotor pole area can be modified to accommodate greater tolerances of the individual components. This includes the tolerance of the tubular support structure. A further advantage is that the tubular support structure provides a frame for simply assembling the rotor according to the invention with good concentricity.

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

  In some embodiments of the present invention, the rotor pole area is formed from a soft magnetic material, such as soft magnetic powder. Forming the rotor pole area from soft magnetic powder can simplify the manufacture of the rotor, and flux concentration can be made more efficient by taking advantage of an effective three-dimensional flux path. is there.

  In some embodiments of the present invention, the tubular support structure is comprised of a non-magnetic material, such as aluminum or plastic, such as extruded aluminum or injection molded plastic, and / or other suitable non-magnetic material. By manufacturing a tubular support structure of non-magnetic material, the magnetic properties of the rotor are not disturbed.

  According to a first aspect, a permanent magnet is fitted in the recess of the tubular support structure, and the rotor pole area is arranged between two adjacent permanent magnets. By fitting the permanent magnet into the recess of the support structure, the permanent magnet extends radially beyond the rotor pole area. This allows a more efficient utilization of the magnetic flux generated by the permanent magnet.

  In some embodiments of the present invention, the rotor pole area is fitted within the recess of the support structure.

  In some embodiments of the present invention, the permanent magnet or rotor pole area is fitted into the recess of the tubular support structure by a friction fit formed by the sidewall of the recess. By using a friction fit, a simple and reliable method of securing the permanent magnet or rotor pole area is provided. The friction fit can be generated by designing the recess to be slightly smaller than the permanent magnet or rotor pole area. The adjustment of the frictional force can be easily done by deformation under the control of the recess walls, for example some lip of material that can be bent with a small enough desired force not to damage the pole area or the magnet This can be easily done by an integral design mechanism.

According to a second aspect, the present invention is a rotor magnetic pole area for a rotor as described above, wherein when fitted into the recess, the rotation extends radially from the recess defining a radial axis. In the magnetic pole area,
A first constant width section that forms a first end of the rotor pole area and is adapted to be at least partially fitted into a recess of the support structure, the first constant width section. Has a first constant width section in which the width of the rotor pole section in the first constant width section is constant,
A tapered section starting from the end of the first constant width section, wherein the tapered section has two non-parallel side walls, whereby the rotor pole area in the tapered section; It relates to a rotating magnetic pole area having a tapered section with a non-constant width.

  Thus, the tapered section of two adjacent rotor pole sections forms a slot opening with parallel walls for the permanent magnet, thereby making the expensive permanent magnet geometry simple and low cost It can be so.

  In some embodiments of the invention, the sidewall of the first constant width section is parallel to the radial axis.

  In some embodiments of the invention, the sidewall of the tapered section is non-parallel to the radial axis.

  As used herein, the length of the rotor pole area is defined as the dimension that extends along the radial axis of the tubular support structure when the rotor pole area is fitted into the tubular support structure. The height of the area is defined as the dimension that extends along the axis of the tubular support structure when the rotor pole area is fitted into the tubular support structure, and the width of the rotor pole area is the length of the rotor pole area. It is defined as the dimension perpendicular to the height and height.

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

  The tapered section may have any length. In some embodiments of the present invention, the length of the tapered section represents 40-95 percent of the total length of the rotor pole area. In some embodiments of the present invention, the length of the tapered section corresponds to 60-90 percent of the total length of the rotor pole area. The length of the tapered section can be determined by the radial length of the permanent magnet. In some embodiments of the invention, the two sidewalls of the tapered section are straight walls that are angled toward the central radial axis so that the width of the rotor pole area is equal to the first As the distance from the constant width section increases, it decreases monotonically along the radial axis. This design is advantageous when the rotor pole area is used on the outer rotor. In some embodiments of the present invention, the two sidewalls of the tapered section are straight walls that are angled away from the central radial axis so that the width of the rotor pole area is equal to the first As the distance from the constant width section increases, it increases monotonically along the radial axis. This design is advantageous when the rotor pole area is used with the inner rotor.

  In order to ensure the cylindrical shape of the rotor, in some embodiments of the present invention, the rotor pole area preferably comprises a tapered section. As described above, the tapered section ensures that the width of the rotor pole area is expanded for the inner rotor and reduced for the outer rotor. However, by further having a first constant width section adapted to be positioned in the recess of the tubular support structure, the rotor pole area can be inserted into the recess by movement along the radial axis. Therefore, the assembly of the rotor using the rotor magnetic pole area can be simplified. This has been shown to be superior to the technique of pushing the rotor pole area into the recess by axial movement. This is because the height of the rotor pole area is typically large so that such indentation will make the rotor pole area unstable at the beginning of the insertion process. Thereby, the manufacturing cost can be reduced. Furthermore, the first constant width section serves to ensure a tighter fit when the rotor pole area is used for the inner rotor.

  In some embodiments of the present invention, the rotor pole section further comprises a second constant width section, the second constant width section starting from the point where the tapered section ends, 2 and the side walls of the second constant width section are parallel, so that the width of the rotor pole area is constant in the second constant width section.

  In some embodiments, the two sidewalls of the second constant width section are parallel to the radial axis.

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

  By having a second constant width section, the width of the space formed by the two adjacent rotor pole sections can be reduced from the point where the second constant width section begins. Thereby, it is possible to prevent the magnets arranged in the space from falling out of the pockets in the radial direction.

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

According to a third aspect, the present invention is a method of manufacturing a rotor pole area as disclosed above and below using powder compression, comprising:
Obtaining a die having a reversal shape of the rotor pole area disclosed above and below, comprising a first constant width section and a second constant width section;
Filling the die with magnetic powder, such as 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 front punches moves relative to the other punch along the radial axis of the resulting rotor pole area and is partially in at least one of the first constant width section or the second constant width section of the die And thereby the length of at least one of the first constant width section or the second constant width section of the resulting rotor pole area is shortened during consolidation.

  The magnetic powder may be, for example, soft magnetic iron powder, powder containing Co or Ni, or an alloy containing a part thereof. The soft magnetic powder may be substantially pure water atomized iron powder or sponge iron powder having irregular shaped particles coated with an electrical insulator. In this context, the term “substantially pure” means that the powder is substantially free of inclusions and the amount of impurities O, C, and N is kept to a minimum. The average particle size is generally less than 300 μm and greater than 10 μm.

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

  The electrical insulator of the powder particles may be made of an inorganic material. Particularly suitable is the type of insulator disclosed in US Pat. No. 634,265 (incorporated herein by reference), which is substantially pure having an insulating oxygen and phosphorus containing barrier. The present invention relates to particles of base powder made of iron. Powders with insulated particles are available as Somaloy® 500, Somaloy® 550, or Somaloy® 700 available from Hoeganas AB (Sweden).

  Thereby, the rotor pole area is efficiently performed in the same operation by use of a powder forming method, where the formation is performed in a single compacting tool setup.

  By having a constant width section in the die, the punch can move into the section to varying degrees without damaging the die. This allows for greater tolerances in iron powder compression and further reduces manufacturing costs.

According to a fourth aspect, the present invention is a method for manufacturing a rotor for a modulating pole machine, wherein the rotor comprises a tubular support structure that defines a circumferential mounting surface and is tubular. The support structure comprises a plurality of elongated recesses periodically positioned on the mounting surface along the mounting surface of the support structure, the elongated recesses extending in the axial direction of the tubular support structure, each recess having two sidewalls And the rotor further comprises a plurality of permanent magnets circumferentially separated from each other by an axially extending rotor pole section formed from a soft magnetic material,
At least partially disposing a permanent magnet or rotor pole area within each of the recesses, wherein the permanent magnet or rotor pole area extends radially out of the recess, thereby allowing the two adjacent recesses to Forming a plurality of slots therebetween;
Positioning a permanent magnet or rotor pole area within each formed slot.

  In some embodiments of the present invention, the method further includes positioning an air gap fixture concentrically with the support structure, wherein the rotor pole area or permanent magnet faces the air gap fixture. A side of the permanent magnet or rotor pole area is adjusted radially in the recess so that it contacts the air gap fixture.

  The air gap fixture is preferably cylindrical when assembling the outer rotor and tubular when assembling the inner rotor. The air gap fixture may have an axial length that is approximately equal to the axial length of the support structure, an axial length that is smaller than the support structure, or an axial length that exceeds the axial length of the support structure, etc. Can have any axial length.

  By using an air gap fixture, a quick and simple method of assembling a rotor according to the present invention is provided, reducing manufacturing costs. Further, the air gap fixture can be used in an automated manufacturing process, thereby further reducing manufacturing costs. The air gap fixture also serves to ensure that there is not much variation in the final product.

  In some embodiments of the present invention, the air gap fixture further comprises a magnetic device for increasing the contact pressure between the rotor pole area or permanent magnet and the air gap fixture.

  The magnetic device may be a configuration of a magnetic flux circuit in which pole pieces or permanent magnets form part of the magnetic circuit, so that the magnetic force caused by the magnetic circuit is a desired air gap geometry of the application machine. The pole piece and the permanent magnet can be held in proximity to the fixture present. The magnetic circuit can include a magnetic field source, which can be an electromagnet using wires and coils that maintain a controllable current to generate the magnetic field, or can be by an external permanent magnet. The external permanent magnet may be a rotor permanent magnet. In addition, there may be axially extending radial recesses on the surface of the magnetic fixture surface, further improving the geometric control of the rotor pole pieces and permanent magnets during the assembly process.

  By using an air gap fixture with a magnetic device, magnetic energy can be used to adjust the position of the rotor pole area. This further reduces manufacturing costs.

  According to a fifth aspect, the present invention is an electrical rotating machine, the first stator core area being substantially circular and including a plurality of teeth, and the substantially circular and plurality of teeth. A second stator core section comprising: a core disposed between the first circular stator core section and the second circular stator core section; and the rotor disclosed above and / or below A first stator core section, a second stator core section, a coil, and a rotor surrounding a common geometric axis, and the first stator core section; The plurality of teeth of the second stator core area are arranged to protrude toward the rotor, and the teeth of the second stator core area are circumferential with respect to the teeth of the first stator core area The present invention relates to an electrical rotating machine that is shifted in direction.

  Various aspects of the present invention can be implemented in a variety of forms, including the rotor and rotor pole areas described above and below, and additional product means, which form at least one of the aspects described above. One or more corresponding to preferred embodiments described in connection with at least one of the aspects and / or the dependent claims, each generating one or more of the benefits and advantages mentioned in relation to Each of the preferred embodiments. Further, it should be understood that the embodiments described in connection with one of the aspects described herein may be applied to other aspects.

  The above and / or additional objects, features, and advantages of the present invention will be further described by the following illustrative, non-limiting detailed description of embodiments of the present invention with reference to the accompanying drawings.

1 is an exploded perspective view of a prior art modulation pole machine. FIG. 1 is a cross-sectional view of a prior art modulation pole machine. FIG. 6 illustrates an outer rotor tubular support structure according to some embodiments of the present invention. FIG. 4 is a more detailed view of a recess in the outer rotor according to some embodiments of the present invention. Fig. 6 shows a tubular support structure comprising a plurality of permanent magnets 203 of the outer rotor according to some embodiments of the present invention. 2 illustrates an outer rotor according to some embodiments of the present invention. FIG. 6 shows an inner rotor according to some embodiments of the present invention. FIG. 6 illustrates a rotor pole area 401 for an outer rotor according to some embodiments of the present invention. FIG. 6 illustrates a method of manufacturing a rotor pole area 502 according to some embodiments of the present invention. 2 illustrates an outer rotor according to some embodiments of the present invention. FIG. 4 is a more detailed view of a portion of an outer rotor according to some embodiments of the present invention. FIG. 3 shows a rotor according to some embodiments of the invention. FIG. 4 is a more detailed view of a rotor according to some embodiments of the invention. (A) and (b) show an example of a magnetic air gap fixing device. It is a figure which shows an example of a modulation | alteration pole machine. In particular, (a) shows a perspective view of the active part of the machine including the stator 10 and the rotor 30, and (b) shows an enlarged view of a part of the machine. An example of the stator 10 of the modulation pole machine of FIG. 9 is shown. It is a figure which shows an example of a three-phase modulation pole machine. In particular, (a) shows an active part of an example of a three-phase modulation pole machine, and (b) shows an example of a stator of the machine of (a).

  The following description refers to the accompanying drawings. The accompanying drawings illustrate by way of example the manner in which the invention may be practiced.

  The present invention is in the field of modulating pole electric machine 100, an example of which is shown in schematic exploded perspective view in FIG. 1a. The stator 10 of a modulating pole electric machine is basically characterized by the use of a central single winding 20 that provides a magnetic force to a plurality of teeth 102 formed by a soft magnetic core structure. Here, the stator core is formed around the winding 20. In contrast, in other common electromechanical structures, the windings are formed around the core area of individual teeth. Examples of modulated pole machine topologies are sometimes recognized as, for example, claw pole machines, claw feet machines, Landell machines, or TFM machines. More particularly, the illustrated modulation pole electric machine 100 includes two substantially circular stator core sections 14, 16 each including a plurality of teeth 102, a first circular stator core section, and a second circular section. A coil 20 disposed between the stator core sections and a rotor 30 including a plurality of permanent magnets 22 are provided. In addition, the stator core sections 14, 16, the coil 20, and the rotor 30 surround a common geometric axis 103, and the teeth of the two stator core sections 14, 16 provide a closed circuit flux path. In order to form, it is arranged to protrude toward the rotor 30. The machine in FIG. 1 is of the radial type since the teeth of the stator project radially towards the rotor, in which case the stator surrounds the rotor. However, the stator can also be arranged inside the rotor and this type is also shown in some of the following figures. The scope of the invention presented below is not limited to any specific type of modulating pole electric machine, but can be applied equally to both axial and radial type machines, and for rotors. Therefore, the present invention can be applied to a stator arranged on the inner side and a stator arranged on the outer side. Similarly, the present invention is not limited to single phase machines but can be applied to multiphase machines.

  The active rotor structure 30 is composed of an even number of segments 22, 24, half of the segments, also referred to as the rotor pole area 24, are formed from soft magnetic material and the other half are formed from permanent magnet material 22. The The state of the art method is to manufacture these segments as separate components. Often, the number of segments can be relatively large, typically on the order of 10-50 individual areas. The permanent magnet 22 is arranged such that the magnetization direction of the permanent magnet is substantially circumferential, that is, the north and south poles are substantially oriented in the circumferential direction, respectively. Furthermore, every other permanent magnet 22 counted in the circumferential direction is arranged to have a magnetization direction opposite to that of the remaining permanent magnets. The magnetic function of the soft magnetic pole area 24 in the desired mechanical structure is completely three-dimensional, and the soft magnetic pole area 24 has a high permeability in all three spatial directions, making various magnetic fluxes efficient. It is necessary to be able to bear on. Conventional designs that use laminated steel sheets do not exhibit the required high permeability in the direction perpendicular to the plane of the steel sheet. Here, it is beneficial to use soft magnetic structures and materials that exhibit higher magnetic flux isotropy than the state of the art laminated steel sheet structures.

  FIG. 1b shows the same radially modulated pole electric machine as in FIG. 1 in a cross-sectional view of the assembled machine, with the stator teeth 102 extending towards the rotor, and two stator cores It shows more clearly how the stator teeth of the zones 14, 16 are offset in the rotational direction with respect to each other.

  In the following, examples of rotors that can be used as part of the modulating pole electric machine shown in FIGS. 1a and 1b will be described in more detail. It should be understood that the rotor described herein can also be used with stators of different types of modulating pole machines than those described above.

  FIG. 2a shows an outer rotor tubular support structure 201 according to some embodiments of the present invention. Tubular support structure 201 has a radius and a height, where the height extends along the axial axis of tubular support structure 201. The tubular support structure 201 includes a plurality of recesses 202 that are periodically positioned around the periphery of the support structure 201 on a circumferential mounting surface that is an inner surface of the tubular support structure 201. The tubular support structure 201 may be made of an impermeable material, for example, a nonmagnetic material such as aluminum or plastic. The plurality of recesses 202 extend in the axial direction of the tubular support structure. FIG. 2b shows a more detailed view of the recess. The recess comprises two parallel side walls 205 and 206 extending radially in the tubular support structure. Two parallel side walls 205 and 206 are connected by an end wall 207. The recess extends over the entire height of the tubular support structure 201.

  FIG. 2c shows a tubular support structure comprising a plurality of permanent magnets 203 of the outer rotor according to some embodiments of the present invention. A permanent magnet 203 is fitted in each of the plurality of recesses. The permanent magnet 203 can be secured in the recess 202 by a friction fit and / or by any type of securing means such as an appropriate type of adhesive.

  FIG. 2d shows an outer rotor according to 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 areas 204.

  The rotor pole area 204 is fitted in a slot formed by a permanent magnet fitted in the recess 202 of the support structure 201. The rotor pole area 204 can be secured to the permanent magnet and / or support structure by a friction fit made by the permanent magnet and / or by any type of securing means such as a suitable type of adhesive. . The permanent magnet 203 extends further outward in the radial direction than the rotor magnetic pole area 204 when fitted in the recess 202 of the support structure 201. Thereby, the polar area can use a larger proportion of the magnetic field generated by the permanent magnet 203 to generate the rotor magnetic field. This reduces the magnetic requirements of the permanent magnet, and thus smaller permanent magnets can be used, reducing manufacturing costs. FIG. 3 shows an inner rotor corresponding to the outer rotor shown in FIG. 2d.

  FIG. 4 illustrates a rotor pole area 401 for an outer rotor according to some embodiments of the present invention. The rotor pole area 401 has a width 407 and a length 406. The rotor magnetic pole section 401 includes three sections, namely a first constant width section 402, a tapered section 403, and a second constant width section 404. The first constant width section 402 is adapted to fit at least partially in the recess of the support structure. The first constant width section 402 comprises two sidewalls parallel to the radial axis of the rotor pole section 401 so that the width of the rotor pole section 401 is constant in the first constant width section 402. Guarantee. The length of the first constant width section may correspond approximately to the depth of the recess, for example, the spread of the two sidewalls of the recess. The tapered section 403 comprises two straight sidewalls having equal but opposite angles with respect to the radial axis of the rotor pole section 401, so that the width of the tapered section is the first constant width section 402. Monotonically decreases with increasing distance from However, in other embodiments, the sidewalls of the tapered section are mirrored such that the distance from the first constant width section 402 increases and the width of the rotor pole section in the tapered section increases monotonically. The The second constant width section 404 comprises two sidewalls parallel to the radial axis of the rotor pole area 401 so that the width of the rotor pole section 401 is constant in the second constant width section. Guarantee. Furthermore, the second constant width section comprises a concave end 405 when the rotor pole area is used for the outer rotor and is convex when the rotor pole area is used for the inner rotor. With an end. In some embodiments of the present invention, the rotor pole area comprises only a first constant width section 402 and a tapered section 403.

  FIG. 5 illustrates a method of manufacturing a rotor pole area 502 according to some embodiments of the present invention. The rotor pole area 502 is manufactured by filling a die 501 with iron or iron-based powder and compressing the iron powder with two punches 505 and 506. The die 501 has a reverse shape of the desired rotor pole area as shown in FIG. 4, for example, but the lengths of the first constant width section 503 and the second constant width section 504 of the die 501 are extended. Is different. This allows the punches 505 and 506 to move in the radial direction of the resulting rotor pole area 502 and partially enters the first constant width section 503 and the second constant width section 504 of the die 501. , Thereby compressing the iron powder in the die 501 to form the rotor pole area 502.

  FIG. 6a shows an outer rotor according to some embodiments of the present invention. The outer rotor comprises a tubular support structure 601, a plurality of permanent magnets 603, and a plurality of rotor pole areas 604 as shown in FIG. The tubular support structure includes a plurality of recesses 602 that are periodically positioned around the periphery of the support structure 601. The rotor pole area 604 is fitted in a plurality of recesses 602 in the tubular support structure 601 and the permanent magnet 603 is fitted in a slot formed by two adjacent rotor pole areas 604.

  FIG. 6b is a more detailed view of a portion of the outer rotor shown in FIG. 6a. FIG. 6 b shows how the shape of the rotor pole area 604 fitted in the recess 602 of the tubular support structure 601 affects the space formed by two adjacent rotor pole areas 604. The tapered section 607 of the rotor pole section 604 indicates that the width of the space formed between two adjacent rotor pole sections 604 is constant along the tapered section 607 of the rotor pole section 204. Guarantee. Thereby, the permanent magnet 605 having a certain width can be fitted into the space. By providing a second constant width section 608 in the rotor pole section 604, the width of the space formed between two adjacent rotor pole sections 604 is such that the second constant width section of the rotor pole section 604 is Decrease along 608. This prevents the permanent magnet 603 confined in the space from sliding out of the rotor in the radial direction.

  FIG. 7 a shows a rotor according to some embodiments of the present invention that further comprises an air gap fixture 605. The air gap fixture can ensure accurate positioning of the rotor pole area during manufacture of the rotor. The air gap fixture 605 may have a cylindrical shape, or may have a conical shape when assembling the outer rotor, and may have a tubular shape when assembling the inner rotor. An air gap fixture 605 can be used to adjust the rotor pole area 604 radially within the recess 602. The air gap fixture may comprise a magnetic device that allows magnetic energy to be used to adjust the radial position of the rotor pole area 604 within the recess 602. After the rotor is assembled, the air gap fixture can be removed. FIG. 7b shows a more detailed view of FIG. 7a. By using an air gap fixture, a quick and simple method of assembling a rotor according to the present invention is provided, reducing manufacturing costs.

  FIGS. 8A and 8B show an example of a magnetic air gap fixing device. The magnetic air gap fixture 605 includes a generally cylindrical body having a circumferential recess 851 for receiving the coil 852, which places the rotor pole area 853 in place. Provide a controllable magnetic field to maintain.

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

  The machine comprises a stator 10, which comprises a central single winding 20, which provides a magnetic force to a plurality of teeth 102 formed by a soft magnetic core structure. The stator core is formed around the winding 20. In contrast, in other common electromechanical structures, the windings are formed around the core area of individual teeth. More specifically, the modulating pole electric machine of FIGS. 9 and 10 includes two substantially annular stator core sections 14, 16 each including a plurality of teeth 102, a first circular stator core section, and a first circular stator core section. A winding 20 disposed between two circular stator core sections and a rotor 30 including a plurality of permanent magnets 22. Further, the stator core sections 14, 16, the coil 20, and the rotor 30 surround a common geometric axis, and the teeth 102 of the two stator core sections 14, 16 provide a closed circuit flux path. In order to form, it is arranged to protrude toward the rotor 30. The stator teeth of the two stator core sections 14, 16 are offset circumferentially with respect to each other.

  Each stator section includes an annular core back portion 261 that provides a circumferential flux path between adjacent teeth. In addition, the stator comprises a flux bridge or yoke component 18 that provides at least one axial flux path between the two stator core sections. In the machine in FIGS. 9 and 10, the stator teeth project radially towards the rotor, in which case the rotor surrounds the stator. However, the stator can also be arranged outside the rotor. The rotor embodiments described herein can be used in single-phase and / or multi-phase machines.

  The active rotor structure 30 is composed of an even number of segments 22, 24, half of the segments, also referred to as the rotor pole area 24, are formed from soft magnetic material and the other half are formed from permanent magnet material 22. The These segments can be manufactured as individual components. For illustration purposes, only the magnetically active portion of the rotor is shown in FIGS. The tubular support structure described herein is not explicitly shown in FIGS.

  The permanent magnet 22 is arranged such that the magnetization direction of the permanent magnet is substantially the circumferential direction, that is, the N pole and the S pole are respectively substantially oriented in the circumferential direction. Further, every other permanent magnet 22 counted in the circumferential direction is arranged to have a magnetization direction opposite to that of the adjacent permanent magnet. The magnetic function of the soft magnetic pole area 24 in the desired mechanical structure is completely three-dimensional, and each soft magnetic pole area 24 has a high permeability in all three spatial directions, making various fluxes efficient. Can bear it.

  This design of the rotor 30 and the stator 10 has the advantage of allowing magnetic flux concentration from the permanent magnet 22, so that the surface of the rotor 30 facing the teeth of the stator 10 is adjacent to the adjacent permanent magnet 22. Both can provide total magnetic flux to the facing tooth surfaces. The magnetic flux concentration can be viewed as a function of the area of the permanent magnet 22 facing each pole area 24 divided by the area facing the teeth. In particular, due to the circumferential misalignment of the teeth, the teeth facing the pole area create an active air gap that extends only over a portion of the axial extent of the pole area. Nevertheless, the magnetic flux from the entire axial extent of the permanent magnet is directed axially and radially in the pole area towards the active air gap. These flux concentration characteristics of each pole section 24 allow a low cost, weak permanent magnet to be used as the rotor permanent magnet 22 and still achieve a very high air gap flux density. Magnetic flux concentration can be facilitated by making the pole area from magnetic powder to achieve an effective three-dimensional magnetic flux path. Furthermore, this design also allows the use of magnets to be more efficient than the corresponding type of machine.

  With continued reference to FIGS. 9 and 10, the single-phase stator 10 may be used as a stator for a single-phase machine as shown in FIGS. 9 and 10, and / or one stator for a multi-phase machine. It may be used as a phase, for example one of the stator phases 10a-c of the machine of FIG. The stator 10 comprises two identical stator core sections 14, 16 each comprising a plurality of teeth 102. Each stator core area is made of soft magnetic powder compacted into a predetermined shape with a press tool. When the stator core areas have the same shape, they can be pressed with the same tool. Then, in a second operation, the two stator core sections are joined together to integrally form a stator core having radially extending stator core teeth. Here, the teeth of one stator core area are offset in the axial and circumferential directions with respect to the teeth of the other stator core area.

  Each stator core section 14, 16 can be consolidated into a piece. Each stator core section 14, 16 may be formed as an annular disc having a substantially circular central opening defined by a radially inner edge 551 of the annular core back portion 261. The teeth 102 project radially outward from the radially outer edge of the annular disk-shaped core back. The annular portion between the inner edge 551 and the teeth 102 provides radial and circumferential flux paths and a circumferential cavity sidewall that houses the coil 20. Each stator core area includes a circumferential flange 18 at or near the inner edge 551. In the assembled stator, the circumferential flange 18 is arranged inside the stator core area, ie on the side facing the coil 20 and the other stator core area. In the embodiment shown in FIGS. 9 and 10, the stator core sections 14, 16 are formed as identical components. In particular, both stator core sections are provided with flanges 18 each projecting towards the other stator core section. In the assembled stator, the flanges 18 can abut one another to form an axial flux bridge and provide an axial flux path between the stator core sections. Thus, in the assembled stator for the outer rotor machine, the coil surrounds the stator core back formed by the flange 18.

  Each tooth 102 has an interface 262 that faces the air gap. During machine operation, magnetic flux is transmitted through interface 262, through the air gap, and through the corresponding interface of the rotor pole pieces.

  FIG. 11 (a) shows the active part of an example of a three-phase modulation pole machine, and FIG. 11 (b) shows an example of the stator of the machine of FIG. 11 (a). This machine includes a stator 10 and a rotor 30. Stator 10 includes three stator phase sections 10a, b, c, each similar to that described in connection with FIGS. In particular, each stator phase section comprises a respective stator component pair 14a, 16a; 14b, 16b; and 14c; 16c, each pair holding one circumferential winding 20a-c, respectively. To do.

  Thus, similar to the examples of FIGS. 9 and 10, each electrically modulated pole machine stator phase section 10a-c of FIG. 11 comprises a central coil 20a-c, eg, a single winding, where the central coils 20a-c are Magnetic force is supplied to the plurality of teeth 102 formed by the soft magnetic core structure. More particularly, each stator phase 10a-c of the illustrated electrical modulation pole machine 100 includes two stator core sections 14 each having a plurality of teeth 102 and being substantially annular, and a first circular stator. A coil 20 disposed between the core section and the second circular stator core section. Furthermore, the stator core section 14 and the coil 20 of each stator phase 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 disposed coaxially with the stator 10, surrounds the stator, and forms an air gap between the stator and the rotor teeth 102. The rotor can be provided as alternating permanent magnets 22 and pole pieces 24 as described in connection with FIGS. 9 and 10, but extends axially across all stator phase areas.

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

  The embodiments of the invention disclosed herein can be used for direct wheel drive motors for electric bicycles or other electric vehicles, particularly lightweight vehicles. Such applications may impose requirements for high torque, relatively low speed, and low cost. These requirements are met by a motor with a relatively large number of magnetic poles in a compact geometry using small volume permanent magnets and wire coils to meet and meet the cost requirements of high rotor assembly routines. can do.

  In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims or described in different embodiments does not mean that a combination of these measures cannot be used by itself.

  As used herein, the term “comprising / comprising” identifies the presence of a described feature, integer, step, or component, and includes one or more other features. It is emphasized that this does not exclude the presence or addition of integers, steps, components, or the presence or addition of groups thereof.

Claims (19)

A rotor for a modulating pole machine, wherein the rotor is configured to generate a rotor magnetic field for interacting with the stator magnetic field of the stator of the modulating pole machine;
A tubular support structure defining a circumferential mounting surface, wherein the mounting surface has a plurality of elongated recesses extending in the axial direction of the tubular support structure;
A plurality of permanent magnets magnetized in a circumferential direction of the rotor so as to generate the rotor magnetic field, the plurality of permanent magnets at least in a radial direction the rotor magnetic field generated by the permanent magnets; A plurality of permanent magnets separated from each other in the circumferential direction of the rotor by axially extending rotor magnetic pole sections,
The plurality of permanent magnets extend at least partially radially into each of the plurality of recesses, and each rotor pole area is disposed between two adjacent permanent magnets.   The plurality of recesses are adapted to adjust the position of the permanent magnet in the radial direction, whereby the radial length of a part of each permanent magnet extending outward from the recess is made adjustable. The rotor according to claim 1.   The rotor according to claim 1 or 2, wherein each permanent magnet is in contact with two side walls of the recess.   The rotor according to any one of claims 1 to 3, wherein the permanent magnet is fitted into the recess of the tubular support structure by a friction fit formed by a side wall of the recess. A rotor for a modulating pole machine, wherein the rotor is configured to generate a rotor magnetic field for interacting with the stator magnetic field of the stator of the modulating pole machine;
A tubular support structure defining a circumferential mounting surface, wherein the mounting surface has a plurality of elongated recesses extending in the axial direction of the tubular support structure;
A plurality of permanent magnets magnetized in a circumferential direction of the rotor so as to generate the rotor magnetic field, the plurality of permanent magnets at least in a radial direction the rotor magnetic field generated by the permanent magnets; A plurality of permanent magnets separated from each other in the circumferential direction of the rotor by axially extending rotor pole areas,
At least one rotor pole area extends at least partially radially into one of the plurality of recesses, and the rotor pole area is fitted in the recess of the support structure when the radial axis is Extending radially from the recess defining the rotor, and the rotor pole area is
A first constant width section forming a first end of the rotor pole area and adapted to be at least partially fitted into a recess of the support structure, wherein the first constant width section A first constant width section having two parallel sidewalls so that the width of the rotor pole area is constant;
Two non-parallel sidewalls that are tapered sections starting from the end of the first constant width section, the tapered section being such that the width of the rotor pole section in the tapered section is not constant And a rotor having a tapered section.   The rotor pole section further comprises a second constant width section starting from the point where the tapered section ends and forming a second end of the rotor pole section, the width of the rotor pole section 6. The rotor according to claim 5, wherein side walls of the second constant width section are parallel so that is constant in the second constant width section.   The plurality of recesses are adapted to radially adjust the position of the rotor pole area, thereby adjusting the radial length of a portion of each rotor pole area extending out of the recess. The rotor according to claim 5 or 6, which is made possible.   The rotor according to any one of claims 5 to 7, wherein the rotor magnetic pole area is fitted into the recess of the tubular support structure by a friction fit formed by a sidewall of the recess.   The rotor according to any one of claims 1 to 8, wherein the circumferential mounting surface is an inner surface of the tubular support structure.   The rotor according to any one of claims 1 to 9, wherein the circumferential mounting surface is an outer surface of the tubular support structure.   11. A rotor as claimed in any one of the preceding claims, wherein the rotor pole area is made from a soft magnetic material.   The rotor according to any one of claims 1 to 11, wherein the tubular support structure is made of a nonmagnetic material such as aluminum or plastic. In the rotor pole area,
A first constant width section that forms a first end of the rotor pole area and is adapted to be at least partially fitted in a recess of a support structure, wherein the first constant width section A first constant width section having two parallel sidewalls so that the width of the rotor pole area of
A tapered section starting from a point where the first constant width section ends, and a tapered section having two non-parallel side walls so that the width of the rotor magnetic pole section in the tapered section is not constant; Rotor pole area with.   And further comprising a second constant width section starting from the end of the tapered section and forming a second end of the rotor pole section, wherein the width of the rotor pole section is the second constant width. The rotor pole area of claim 13, wherein the side walls of the second constant width section are parallel so as to be constant in the section. A method for producing a rotor pole area according to claim 13 or 14 using powder compression, comprising:
Obtaining a die having an inverted shape of a rotor pole section having a first constant width section and a second constant width section;
Filling the die with magnetic powder;
Compressing the magnetic powder in the die using at least two punches;
At least one of the punches moves relative to the other punch along a radial axis of the rotor pole area to be manufactured, and at least one of the first constant width section or the second constant width section of the die Method of partially entering one, whereby the length of at least one of the first constant width section or the second constant width section of the rotor pole area to be manufactured is shortened. A method for manufacturing a rotor for a modulating pole machine, wherein the rotor has a tubular support structure that defines a circumferential mounting surface, the tubular support structure being a part of the support structure. A plurality of elongated recesses periodically positioned on the mounting surface along the mounting surface, the elongated recesses extending in an axial direction of the tubular support structure, each recess having two sidewalls; The rotor further comprises a plurality of permanent magnets, wherein the plurality of permanent magnets are circumferentially separated from each other by an axially extending rotor pole section formed from a soft magnetic material,
At least partially disposing a permanent magnet or rotor pole area within each of the recesses, wherein the permanent magnet or rotor pole area extends radially out of the recess and thereby two adjacent Forming a plurality of slots between the recesses;
Placing a permanent magnet or rotor pole area within each formed slot.   And further comprising the step of positioning an air gap fixture concentrically with the support structure, wherein the rotor pole area or permanent magnet has a side surface of the permanent magnet or rotor pole area facing the air gap fixture. 17. The method of claim 16, wherein the method is adjusted radially within the recess to contact the gap fixture.   The rotor for a modulation pole machine according to claim 17, wherein the air gap fixture further comprises a magnetic device for increasing the contact pressure between a rotor pole area or a permanent magnet and the air gap fixture. Method for manufacturing. A modulation pole machine having a stator and a rotor according to any one of claims 1 to 12, wherein the stator is
First and second stator core sections each including a plurality of teeth projecting radially toward the rotor;
A winding disposed between the first stator core section and the second stator core section;
A rotor pole area extending axially to separate the permanent magnets, wherein teeth of the second stator core area are circumferentially offset relative to the teeth of the first stator core area Extending axially relative to both the first stator core area and the second stator core area;
The direction of magnetization of the permanent magnet of the rotor is substantially circumferential, so that during use of the modulating pole machine, the magnetic flux path generated in the axially extending magnetic pole section is at least circumferentially and The magnetic flux is concentrated in the axial direction from the facing area of the adjacent permanent magnet to the position of one tooth of the stator section, and the magnetization direction of every other permanent magnet is the magnetization of the permanent magnet in between Modulating pole machine that is opposite to direction.

Images