Single-magnetic-pole brushless direct current motor
By designing an asymmetrical distribution of stator salient poles and rotor magnets in a single-pole brushless DC motor, the rotor is driven to rotate using a rotating induction magnetic field, which solves the heat generation problem caused by eddy current losses and improves the efficiency and lifespan of the motor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DALIAN HONGBO NEW ENERGY TECHNOLOGY DEVELOPMENT CO LTD
- Filing Date
- 2025-05-15
- Publication Date
- 2026-05-15
AI Technical Summary
Existing permanent magnet motors generate heat during operation due to eddy current losses, which reduces the conversion efficiency of electrical energy to mechanical energy. Furthermore, high temperatures may cause demagnetization of the rotor permanent magnets, shortening the motor's lifespan.
It adopts a single-pole brushless DC motor structure, with salient poles on the stator and magnets on the rotor. The magnets and salient poles are asymmetrically distributed. The rotor is driven to rotate by rotating induction magnetic field, which reduces eddy current losses. Hall magnetic induction signal sensor is used to sense the rotor position and control the power supply sequence.
It effectively reduces eddy current losses, lowers heat generation, improves the conversion efficiency of electrical energy to mechanical energy, avoids demagnetization of permanent magnets, and extends motor life.
Smart Images
Figure CN224249456U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of motor technology, and more specifically to a single-pole brushless DC motor. Background Technology
[0002] As is well known, in the fields of electromechanical technology and engineering, motors are broadly classified into three categories: DC motors, asynchronous motors, and synchronous motors. With the progress of modern industry and the requirements for energy conservation and emission reduction, asynchronous motors are gradually being phased out. In recent years, brushless DC motors, developed within permanent magnet motors, have been widely used due to their advantages such as simple structure, compact size, high power density, high efficiency, fast dynamic response, and ease of control.
[0003] A brushless DC motor typically consists of a rotor made of permanent magnet materials, such as neodymium iron boron (NdFeB), and a stator made of soft magnetic materials, such as silicon steel sheets, wound with copper wire. Its basic principle is that the electronic commutation function of the motor controller sequentially outputs three phase currents with a 120-degree phase angle. Following a specific logical sequence, these phases are supplied to the stator windings as square wave currents, creating a rotating magnetic field that drives the rotor to rotate, thus converting electrical energy into mechanical energy.
[0004] Current permanent magnet motors suffer from eddy current losses: Most permanent magnet motors currently use neodymium iron boron (NdFeB) strong magnetic material as the rotor's permanent magnet. NdFeB is a conductor. During motor operation, the alternating rotating magnetic field formed by the stator windings and the rotor's magnetic field superimpose each other, generating eddy current induction and heating. Furthermore, the eddy current induction effect increases quadratically with the frequency of the stator's alternating magnetic field. Eddy current heating not only reduces the motor's energy conversion efficiency but also increases the rotor temperature as the frequency of the alternating magnetic field increases, leading to demagnetization of the rotor's permanent magnets and reducing the motor's effective lifespan. Utility Model Content
[0005] To overcome the above-mentioned shortcomings, the purpose of this application is to provide a single-pole brushless DC motor, thereby effectively solving the above-mentioned technical problems.
[0006] To achieve the above objectives, this application adopts the following technical solution:
[0007] This application provides a single-pole brushless DC motor, characterized in that it includes a housing, within which a stator and a rotor are disposed.
[0008] The stator includes an annular silicon steel sheet, and a plurality of salient poles are evenly distributed along the radial direction of the inner ring of the annular silicon steel sheet, and coil windings are wound on the salient poles;
[0009] The rotor includes a rotatable magnetic ring located in the inner ring of the annular silicon steel sheet. A plurality of magnets are uniformly arranged in the radial direction of the outer ring of the magnetic ring. All magnets have the same magnetic polarity on the side facing the salient pole, and the number of magnets is different from the number of salient poles so that the magnets and the salient poles are asymmetrically arranged.
[0010] When the coil winding wound on the salient pole is energized, it forms a rotating induced magnetic field that drives the rotor to rotate in the form of repulsion.
[0011] Furthermore, a Hall magnetic induction signal sensor is embedded in the portion of the salient pole near the magnet.
[0012] Furthermore, the rotor also includes a bearing and a central shaft, the magnetic ring is positioned by the bearing to be mounted on the central shaft, and the magnet is embedded on the outer circumferential surface of the magnetic ring.
[0013] Furthermore, the coil windings wound on the multiple salient poles are all wound in the same direction, have the same power supply direction, and are input at a phase angle of 72 degrees to each other.
[0014] Furthermore, the ratio of the number of salient poles to the number of magnets is 5:4.
[0015] Furthermore, the ratio of the number of salient poles to the number of magnets is 3:2.
[0016] Furthermore, the housing includes a magnetically conductive outer shell, a front cover, and a rear cover. The magnetically conductive outer shell is connected to the front cover, and the magnetically conductive outer shell is connected to the rear cover by fastening screws. The stator and the rotor are disposed in the internal area formed by the magnetically conductive outer shell, the front cover, and the rear cover.
[0017] Furthermore, the interior of the central shaft is a hollow cavity, and the three-phase wire harness of the coil winding extends from inside the housing through the hollow cavity to the outside of the housing.
[0018] Beneficial effects
[0019] This application provides a single-pole brushless DC motor that uses the positional relationship between the salient poles on the stator and the magnets on the rotor, along with the structure where all magnets face the salient poles with the same polarity, to create a repulsive force between the stator and rotor, driving the rotor to rotate. This avoids or reduces eddy current losses caused by the stator's alternating magnetic field penetrating the rotor's permanent magnets, improves the conversion efficiency between the motor's electrical and mechanical energy, reduces heat generation caused by eddy current effects, effectively controls rotor temperature rise, avoids demagnetization of permanent magnets due to high temperatures, and extends the effective lifespan of the motor. Attached Figure Description
[0020] The accompanying drawings are provided to illustrate the technical solutions of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure. The shapes and sizes of the components in the drawings do not reflect actual proportions and are only intended to illustrate the content of this application.
[0021] Figure 1 This is a cross-sectional view of the overall structure of the motor provided in an embodiment of this application.
[0022] Figure 2 This is a schematic diagram of the stator and rotor structure of an electric motor provided in an embodiment of this application.
[0023] Figure 3 The operating principle of the motor provided in an embodiment of this application Figure 1 .
[0024] Figure 4 The operating principle of the motor provided in an embodiment of this application Figure 2 .
[0025] Figure 5 The operating principle of the motor provided in an embodiment of this application Figure 3 .
[0026] Figure 6 The operating principle of the motor provided in an embodiment of this application Figure 4 .
[0027] Figure 7 The operating principle of the motor provided in an embodiment of this application Figure 5 .
[0028] In the above attached figures,
[0029] 1. Magnetic housing; 2. Front cover; 3. Rear cover; 4. Fastening screw; 5. Central shaft; 6. Bearing; 7. Annular silicon steel sheet; 8. Salient pole; 9. Coil winding; 10. Magnetic ring; 11. Magnet; 12. Hall magnetic induction signal sensor; 13. Three-phase wire harness. Detailed Implementation
[0030] The above-described solution will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. The implementation conditions used in the embodiments may be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are generally those in routine experiments.
[0031] Unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. In this document, "electrical connection" includes the situation where constituent elements are connected together by an element having some electrical function. There is no particular limitation on the "electrically functioning element," as long as it enables the transmission and reception of electrical signals between the connected constituent elements. An "electrically functioning element" can be, for example, an electrode or wiring, a switching element such as a transistor, or other functional elements such as a resistor, inductor, or capacitor. "Up," "down," "left," and "right" are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0032] In this application, the terms "upper," "lower," "inner," "middle," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0033] Example
[0034] One embodiment of this application provides a single-pole brushless DC motor, such as... Figure 1 As shown, the motor includes a housing, which includes a magnetic outer shell 1, a front cover 2, and a rear cover 3. The magnetic outer shell 1 is connected to the front cover 2 and the magnetic outer shell 1 is connected to the rear cover 3 by fastening screws 4. The stator and rotor are arranged in the internal area formed by the magnetic outer shell 1, the front cover 2, and the rear cover 3. The interior of the central shaft 5 is a hollow cavity. The three-phase wire harness 13 of the coil winding 9 on the stator extends from the inside of the housing through the hollow cavity to the outside of the housing.
[0035] like Figure 2 As shown, the stator includes an annular silicon steel sheet 7, and multiple salient poles 8 are evenly distributed along the radial direction of the inner ring of the annular silicon steel sheet 7 (five salient poles 8 are used in this embodiment). A coil winding 9 is wound on each salient pole 8. The coil winding 9 wound on each salient pole 8 has the same winding direction and the same power supply direction, and they are input at a phase angle of 72 degrees to each other.
[0036] The rotor includes a bearing 6, a central shaft 5, and a magnetic ring 10. The magnetic ring 10 is located within the inner ring of the annular silicon steel sheet 7 and is positioned on the central shaft 5 by the bearing 6. Magnets 11 are embedded on the outer circumference of the magnetic ring 10. There are multiple magnets 11 (four magnets 11 are used in this embodiment), and the four magnets 11 are evenly arranged radially along the outer ring of the magnetic ring 10. The magnetic polarity of all magnets 11 facing the salient pole 8 is the same (NNNN or SSSS). The number of magnets 11 is not equal to the number of salient poles 8. To achieve an asymmetrical arrangement of magnets 11 and salient poles 8, this embodiment uses a 5:4 ratio of salient poles 8 to magnets 11. In other embodiments, the ratio can be 3:2. The coil winding 9 wound on the salient pole 8 generates a rotating induction magnetic field, driving the rotor to rotate through repulsion. A Hall effect magnetic induction signal sensor 12 is embedded near the magnets 11 on the salient pole 8. The Hall effect magnetic induction signal sensor 12 senses the rotor's operating position and feeds it back to the motor controller. The working principle of this embodiment is as follows:
[0037] Combination Figures 3-7 As shown, the five salient poles on the annular silicon steel sheet of the motor stator are A, B, C, D, and E, and the four magnets on the magnetic ring of the electronic rotor are N1, N2, N3, and N4.
[0038] The stator adopts a five-phase winding structure. When the rotor and stator are in a near-terminal position... Figure 3 The position shown is taken as the starting point, that is, when the magnetic pole N of rotor magnet N3 is between stator salient poles C and D, the motor controller processes the position signal of Hall position sensor and supplies power to windings A, B, and C respectively, so that windings A, B, and C and magnets N1, N2, and N3 form a repulsive force to drive the rotor to rotate 72 degrees clockwise, completing the first step of operation. In this way, a total of 5 steps are needed to complete one 360-degree rotation cycle.
[0039] Based on the above, it can be seen that the rotation of the motor rotor is divided into 5 steps, with each step involving a rotation of 72 mechanical degrees.
[0040] Step 1, when the rotor and stator are in a certain position Figure 3 When the rotor magnet N3 is positioned between the stator salient poles C and D, the motor controller processes the position signal from the Hall position sensor and supplies power to the coil windings on the stator salient poles A, B, and C respectively. This causes the stator salient poles A, B, and C to generate a repulsive force with the magnets N1, N2, and N3, driving the rotor to rotate 72 degrees clockwise. Figure 4 The location shown;
[0041] Step 2, when the rotor and stator are in a certain position Figure 4When the rotor magnet N3 is positioned such that its magnetic pole N is between the stator salient poles D and E, the motor controller processes the position signal from the Hall position sensor and supplies power to the coil windings on the stator salient poles B, C, and D respectively. This causes the stator salient poles B, C, and D to generate a repulsive force with the magnets N1, N2, and N3, driving the rotor to rotate 72 degrees clockwise. Figure 5 The location shown;
[0042] Step 3, when the rotor and stator are in a certain position Figure 5 When the rotor magnet N3 is positioned between the stator salient poles E and A, the motor controller processes the position signal from the Hall position sensor and supplies power to the coil windings on the stator salient poles C, D, and E respectively. This causes the stator salient poles C, D, and E to generate a repulsive force with the magnets N1, N2, and N3, driving the rotor to rotate 72 degrees clockwise. Figure 6 The location shown;
[0043] Step 4, when the rotor and stator are in a certain position Figure 6 When the rotor magnet N3 is positioned such that its magnetic pole N is between the stator salient poles A and B, the motor controller processes the position signal from the Hall position sensor and supplies power to the coil windings on the stator salient poles D, E, and A respectively. This causes the stator salient poles D, E, and A to generate a repulsive force with the magnets N1, N2, and N3, driving the rotor to rotate 72 degrees clockwise. Figure 7 The location shown;
[0044] Step 5, when the rotor and stator are in a certain position Figure 7 When the rotor magnet N3 is in the position shown, that is, between the magnetic pole N of the rotor magnet N3 and the stator salient poles B and C, the motor controller processes the position signal of the Hall position sensor and supplies power to the coil windings on the stator salient poles E, A, and B respectively, so that the stator salient poles E, A, and B and magnets N1, N2, and N3 form a repulsive force to drive the rotor to rotate 72 degrees clockwise, rotating to position ①.
[0045] The above 5 steps complete one power supply cycle, the rotor rotates 360 degrees, and the cycle repeats, so that the motor rotor rotates continuously.
[0046] The above embodiments are only for illustrating the technical concept and features of this application, and are intended to enable those skilled in the art to understand the content of this application and implement it accordingly. They should not be used to limit the scope of protection of this application. All equivalent changes or modifications made in accordance with the spirit and essence of this application should be included within the scope of protection of this application.
Claims
1. A single-pole brushless DC motor, characterized in that: Includes a housing, within which a stator and a rotor are disposed, wherein, The stator includes an annular silicon steel sheet, and a plurality of salient poles are evenly distributed along the radial direction of the inner ring of the annular silicon steel sheet, and coil windings are wound on the salient poles; The rotor includes a rotatable magnetic ring located in the inner ring of the annular silicon steel sheet. A plurality of magnets are uniformly arranged in the radial direction of the outer ring of the magnetic ring. All magnets have the same magnetic polarity on the side facing the salient pole, and the number of magnets is different from the number of salient poles so that the magnets and the salient poles are asymmetrically arranged. When the coil winding wound on the salient pole is energized, it forms a rotating induced magnetic field that drives the rotor to rotate in the form of repulsion.
2. The single-pole brushless DC motor as described in claim 1, characterized in that: A Hall magnetic induction signal sensor is embedded in the part of the salient pole near the magnet.
3. The single-pole brushless DC motor as described in claim 1, characterized in that: The rotor also includes a bearing and a central shaft. The magnetic ring is positioned by the bearing to be mounted on the central shaft, and the magnet is embedded on the outer circumference of the magnetic ring.
4. The single-pole brushless DC motor as described in claim 1, characterized in that: The coil windings wound on the multiple salient poles are all wound in the same direction, have the same power supply direction, and are input at a phase angle of 72 degrees to each other.
5. The single-pole brushless DC motor as described in claim 1, characterized in that: The ratio of the number of salient poles to the number of magnets is 5:
4.
6. The single-pole brushless DC motor as described in claim 1, characterized in that: The ratio of the number of salient poles to the number of magnets is 3:
2.
7. The single-pole brushless DC motor as described in claim 1, characterized in that: The housing includes a magnetically conductive outer shell, a front cover, and a rear cover. The magnetically conductive outer shell is connected to the front cover, and the magnetically conductive outer shell is connected to the rear cover by fastening screws. The stator and the rotor are disposed in the internal area formed by the magnetically conductive outer shell, the front cover, and the rear cover.
8. The single-pole brushless DC motor as described in claim 3, characterized in that: The central shaft has a hollow cavity inside, and the three-phase wire harness of the coil winding extends from inside the housing through the hollow cavity to the outside of the housing.