Single-pole three-phase brushless DC motor

Abstract

The application discloses a single-magnetic-pole three-phase brushless direct current motor, a stator of which comprises annular silicon steel sheets, first convex poles, second convex poles and third convex poles which are uniformly arranged radially in the inner circle of the annular silicon steel sheets, and first coil windings, second coil windings and third coil windings which are respectively arranged on the first convex poles, the second convex poles and the third convex poles; a rotor of which comprises a magnetically conductive ring which is rotatable on the inner circle of the annular silicon steel sheets and first magnetic steels and second magnetic steels which are uniformly arranged radially on the outer circle of the magnetically conductive ring; the magnetic force line directions of the first coil windings, the second coil windings and the third coil are all in a first direction, the magnetic force line directions of the first magnetic steels and the second magnetic steels are all in a second direction, and the first direction and the second direction are opposite to each other so that repulsive force of a magnetic field is generated to drive the rotor to rotate; the magnetic force line directions of the stator and the rotor of the application are opposite to each other, repulsive force is formed to drive the rotor to rotate, and eddy current loss and copper loss generated by the penetration of the alternating magnetic field of the stator into the permanent magnet of the rotor are avoided or weakened.

Description

Technical Field

[0001] This application relates to the field of motor technology, specifically to a single-pole three-phase brushless DC motor. Background Technology

[0002] The driving force of a conventional motor is generated by the rotating magnetic field of the stator and the air gap between the rotor. That is, the rotor will try to make its magnetic field lines align with the magnetic field lines of the stator, forming a torque generated by the attraction between opposite magnetic poles to drive the rotor to rotate. While the stator and rotor generate magnetic forces, their magnetic fields generate self-induction and mutual induction, leading to eddy currents and hysteresis losses.

[0003] Magnetic fields are similar to electric fields. Magnetic field strength has vector characteristics, possessing both magnitude and direction. Taking an internal rotor motor as an example, the magnetic field formed by the stator acts on the rotor, with its magnetic field lines pointing from the N pole to the S pole (N→S). The rotor's permanent magnet magnetic field interacts with the stator, with its magnetic field lines pointing from the S pole to the N pole (S→N). In traditional motors, the N poles of both interact with the S pole, resulting in opposite magnetic field lines attracting each other. However, most brushless DC motors currently use neodymium iron boron (NdFeB) strong magnetic material for the rotor's permanent magnets. NdFeB is a conductor, thus generating eddy currents under the alternating magnetic flux of the stator. During motor operation, the alternating rotating magnetic field formed by the stator windings and the rotor's magnetic field superimpose each other. The two magnetic fields generate self-inductance and mutual inductance through the air gap, leading to eddy currents and heat generation. This eddy current heating increases copper losses and reduces motor efficiency. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings, the purpose of this application is to provide a single-pole three-phase brushless DC motor, thereby effectively solving the above-mentioned technical problems.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] This application provides a single-pole three-phase brushless DC motor, including a housing, within which a stator and a rotor are disposed.

[0007] The stator includes an annular silicon steel sheet and a first salient pole, a second salient pole, and a third salient pole that are radially and uniformly arranged around the inner ring of the annular silicon steel sheet. A first coil winding, a second coil winding, and a third coil winding are respectively wound on the first salient pole, the second salient pole, and the third salient pole.

[0008] The rotor includes a rotatable magnetic ring located in the inner ring of the annular silicon steel sheet and a first magnet and a second magnet that are radially and uniformly arranged around the outer ring of the magnetic ring.

[0009] When the first coil winding, the second coil winding, and the third coil winding are energized, they form a magnetic field with the gap between the first magnet and the second magnet. The magnetic field lines of the first coil winding, the second coil winding, and the third coil winding are all in a first direction, and the magnetic field lines of the first magnet and the second magnet are all in a second direction. The first direction and the second direction are the same so that the magnetic field generates a repulsive force to drive the rotor to rotate.

[0010] Furthermore, the first coil winding, the second coil winding, and the third coil winding are wound in the same direction, wherein,

[0011] The first end of the first coil winding extends to connect to the first energized end, the first end of the second coil winding extends to connect to the second energized end, and the first end of the third coil winding extends to connect to the third energized end. The second ends of the first coil winding, the second end of the second coil winding, and the second end of the third coil winding are connected to each other.

[0012] Furthermore, the portion where the second end of the first coil winding, the second end of the second coil winding, and the second end of the third coil winding are connected to each other extends to connect the fourth energized end.

[0013] Furthermore, Hall effect magnetic induction signal sensors are embedded in the portions of the first salient pole, the second salient pole, and the third salient pole near the rotor.

[0014] 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.

[0015] 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. The interior of the central shaft is a hollow cavity. The three-phase wire harness of the coil winding extends from inside the housing through the hollow cavity to the outside of the housing. Beneficial effects

[0016] In this application, the magnetic lines of force between the stator and rotor of the motor are arranged in opposite directions through the air gap, forming a repulsive force to drive the rotor to rotate. This avoids or reduces the eddy current loss and copper loss caused by the stator's alternating magnetic field penetrating the rotor's permanent magnet, thereby improving the motor's efficiency. At the same time, it reduces the heat generated by the eddy current effect, effectively controls the rotor temperature rise, avoids demagnetization of the permanent magnet due to high temperature, and extends the effective life of the motor. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a cross-sectional view of the overall structure of a single-pole three-phase brushless DC motor provided in an embodiment of this application.

[0019] Figure 2 This is a structural diagram of the stator and rotor of a single-pole three-phase brushless DC motor provided in an embodiment of this application.

[0020] Figure 3 Wiring diagram of a single-pole three-phase brushless DC motor provided in one embodiment of this application. Figure 1 .

[0021] Figure 4 Wiring diagram of a single-pole three-phase brushless DC motor provided in one embodiment of this application. Figure 2 .

[0022] Figure 5 Working principle of a single-pole three-phase brushless DC motor provided in an embodiment of this application Figure 1 .

[0023] Figure 6 Working principle of a single-pole three-phase brushless DC motor provided in an embodiment of this application Figure 2 .

[0024] Figure 7 Working principle of a single-pole three-phase brushless DC motor provided in an embodiment of this application Figure 3 .

[0025] Figure 8 Working principle of a single-pole three-phase brushless DC motor provided in an embodiment of this application Figure 4 .

[0026] Figure 9 Working principle of a single-pole three-phase brushless DC motor provided in an embodiment of this application Figure 5 .

[0027] Figure 10 Working principle of a single-pole three-phase brushless DC motor provided in an embodiment of this application Figure 6 . Detailed Implementation

[0028] 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.

[0029] 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.

[0030] 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. Example

[0031] This embodiment provides a single-pole three-phase brushless DC motor, including a housing, as shown below. Figure 1 As shown, the housing includes a magnetically conductive outer shell 1, a front cover 2, and a rear cover 3. The magnetically conductive outer shell 1 is connected to the front cover 2, and the magnetically conductive outer shell 1 is connected to the rear cover 3 by fastening screws. The stator and rotor are arranged in the internal area formed by the magnetically conductive outer shell 1, the front cover 2, and the rear cover 3.

[0032] like Figure 2-4As shown, the stator includes annular silicon steel sheets and a first salient pole 100, a second salient pole 200, and a third salient pole 300 that are radially and uniformly arranged around the inner ring of the annular silicon steel sheets. A first coil winding LA, a second coil winding LB, and a third coil winding LC are respectively wound on the first salient pole 100, the second salient pole 200, and the third salient pole 300. At the same time, Hall magnetic induction signal sensors are embedded in the parts of the first salient pole 100, the second salient pole 200, and the third salient pole 300 near the rotor. The Hall magnetic induction signal sensors are used to sense the running position of the rotor and feed it back to the motor controller.

[0033] The rotor includes a rotatable magnetic ring located in the inner ring of an annular silicon steel sheet and a first magnet G1 and a second magnet G2 radially and evenly distributed around the outer ring of the magnetic ring. The rotor also includes a bearing 5 and a central shaft 6. The magnetic ring is positioned by the bearing 5 and mounted on the central shaft 6. The magnets are embedded on the outer circumference of the magnetic ring. The interior of the central shaft 6 is a hollow cavity. The three-phase wire harness of the coil winding extends from inside the housing through the hollow cavity to the outside of the housing.

[0034] When energized, the first coil winding LA, the second coil winding LB, and the third coil winding LC form a magnetic field with the gap between the first magnet G1 and the second magnet G2. The magnetic field lines of the first coil winding LA, the second coil winding LB, and the third coil are all in the first direction, while the magnetic field lines of the first magnet G1 and the second magnet G2 are all in the second direction. The first and second directions are the same, so that the magnetic field generates a repulsive force to drive the rotor to rotate. The magnetic field lines between the stator and the rotor of the motor are arranged in opposite directions through the air gap, forming a repulsive force to drive the rotor to rotate. This avoids or reduces the eddy current loss and copper loss caused by the stator alternating magnetic field penetrating the rotor permanent magnet, thereby improving the efficiency of the motor. At the same time, it reduces the heat generated by the eddy current effect, effectively controls the rotor temperature rise, avoids the demagnetization of the permanent magnet due to high temperature, and extends the effective life of the motor.

[0035] The first coil winding LA, the second coil winding LB, and the third coil winding LC are wound in the same direction, wherein,

[0036] The first end a of the first coil winding LA extends to connect to the first energized end A, the first end b of the second coil winding LB extends to connect to the second energized end B, and the first end c of the third coil winding LC extends to connect to the third energized end C. The second end x of the first coil winding LA, the second end y of the second coil winding LB, and the second end z of the third coil winding LC are interconnected. In addition, in some embodiments, the portion where the second end x of the first coil winding LA, the second end y of the second coil winding LB, and the second end z of the third coil winding LC are interconnected extends to connect to the fourth energized end D.

[0037] There are two methods for drawing the wiring diagrams of the motor windings and the controller:

[0038] like Figure 3 As shown, A, B, and C are three phase lines, output by the motor controller. The three voltages with a phase angle difference of 60 degrees are input to LA, LB, and LC of the three-phase windings of the motor, respectively. Two phases are the input terminals, and the other phase is the common output terminal, forming a "two-in-one-out" power supply mode.

[0039] like Figure 4 As shown, A, B, C, and D are the four phase lines, output by the motor controller. The three voltages with a phase angle difference of 60 degrees are input to LA, LB, and LC of the three-phase windings of the motor, respectively. D is the common output terminal.

[0040] The stator adopts a three-phase winding structure and operates in a two-to-two power supply mode: when the rotor and stator are in such a state... Figure 2 Taking the position shown as the starting point, that is, when the magnetic pole N of the first magnet G1 is directly opposite the first salient pole 100, the motor controller inputs the positive power supply to the first coil winding LA. LA is connected in series with the winding LC. The second end z of LC is connected to the negative power supply. The winding LB is in a floating and de-energized state. At this time, according to the right-hand screw theorem, the salient poles of the stator windings LA and LC generate a magnetic field with polarity N, which generates a repulsive force with the N pole of the magnet, driving the rotor to rotate counterclockwise.

[0041] The following is a combination of the above. Figures 5-10 The process of a motor rotor completing one revolution in six steps is detailed below:

[0042] Step ①, when the rotor and stator are in a close proximity Figure 5 Taking the position shown as the starting point, that is, when the magnetic pole N of the first magnet G1 is directly opposite the three-phase winding LA on the stator salient pole, the motor controller inputs the positive power supply to winding a of winding LA, connects LA x to LC c, and connects winding LC in series. Point z of LC is connected to the negative power supply, and winding LB is in a floating and de-energized state. At this time, according to the right-hand screw theorem, the magnetic field polarity generated by the salient poles of stator windings LA and LC is N, which generates repulsive forces f1 and f2 with the N poles of the first magnet G1 and the second magnet G2, respectively. The rotational torque formed by f1 is zero, and the rotational torque formed by f2 is greater than zero. The combined rotational torque is in the counterclockwise direction, which pushes the rotor to rotate counterclockwise by 60 degrees until the position where the second magnet G2 is directly opposite the salient pole of winding LB.

[0043] Step ②: When the magnetic pole N of the rotor's second magnet G2 is directly opposite the salient pole of the winding LB, the motor controller inputs the positive power supply to winding LA at point a. The x-axis of LA is connected to winding LB at point b. The winding LB is connected in series, and the y-axis of winding LB is connected to the negative power supply. The current directions of the two windings are the same, and the magnetic poles formed in the air gap magnetic field are the same. The winding LC is in the de-energized state. At this time, according to the right-hand screw theorem, the magnetic field polarity generated by the salient poles of the stator windings LB and LA is N. They generate repulsive forces with the N poles of the rotor's second magnet G2 and first magnet G1, respectively. The combined rotational torque is in the counterclockwise direction, which in turn pushes the rotor to rotate counterclockwise by 60 degrees until the first magnet G1 is directly opposite the salient pole of the stator winding LC.

[0044] Step 3: When the magnetic pole N of the first magnet G1 of the rotor is aligned with the salient pole of the stator winding LC, the motor controller inputs the positive power supply to the winding LB, then connects the y-axis of the winding LB to the z-axis of the winding LC, connecting the winding LC in series. The z-point of the winding LC is connected to the negative power supply. The current directions of the two windings are the same, and the magnetic poles formed in the air gap magnetic field are the same. The winding LA is in the de-energized state. At this time, according to the right-hand screw theorem, the magnetic field polarity generated by the salient poles of the stator windings LB and LC is N, which repulses the N poles of the first magnet G1 and the second magnet G2 of the rotor, respectively. The combined rotational torque is in the counterclockwise direction, which in turn pushes the rotor to rotate counterclockwise by 60 degrees until the second magnet G2 is aligned with the salient pole of the stator winding A.

[0045] Step 4: When the magnetic pole N of the rotor's second magnet G2 is aligned with the salient pole of the stator winding A, the motor controller inputs the positive power supply to the winding LA, then connects the x-axis of the winding LA to the c-axis of the winding LC, connecting the winding LC in series. The z-point of the winding LC is connected to the negative power supply. The current directions of the two windings are the same, and the magnetic poles formed in the air gap magnetic field are the same. The winding LB is in the de-energized state. At this time, according to the right-hand screw theorem, the magnetic field polarity generated by the salient poles of the stator windings LA and LC is N, which repulses the N poles of the rotor's second magnet G2 and first magnet G1, respectively. The combined rotational torque is counterclockwise, which in turn pushes the rotor to rotate counterclockwise by 60 degrees until the first magnet G1 is aligned with the salient pole of the stator winding LB.

[0046] Step 5: When the magnetic pole N of the first magnet G1 of the rotor is aligned with the salient pole of the stator winding LB, the motor controller inputs the positive power supply to the winding LA. The x-axis of the winding LA is connected to the b-axis of the winding LB in series. The z-axis of the winding LB is connected to the negative power supply. The current directions of the two windings are the same, and the magnetic poles formed in the air gap magnetic field are the same. The winding LC is in the de-energized state. At this time, according to the right-hand screw theorem, the magnetic field polarity generated by the salient poles of the stator windings LB and LA is N. They repel the N poles of the first magnet G1 and the second magnet G2 of the rotor, respectively. The combined rotational torque is in the counterclockwise direction, which in turn pushes the rotor to rotate counterclockwise by 60 degrees until the second magnet G2 is aligned with the salient pole of the stator winding LC.

[0047] Step 6: When the magnetic pole N of the rotor's second magnet G2 is aligned with the salient pole of the stator winding LC, the motor controller inputs the positive power supply to the winding LB. The y-axis of the winding LB is connected to the c-axis of the winding LC, connecting the winding LC in series. The z-point of the winding LC is connected to the negative power supply. The current directions of the two windings are the same, and the magnetic poles formed in the air gap magnetic field are the same. The winding LA is de-energized. At this time, according to the right-hand screw theorem, the magnetic field polarity generated by the salient poles of the stator windings LC and LB is N. This magnetic field generates repulsive forces with the N poles of the rotor's second magnet G2 and first magnet G1, respectively. The combined rotational torque is counterclockwise, which in turn pushes the rotor to rotate counterclockwise by 60 degrees until the first magnet G1 is aligned with the salient pole of the stator winding LA. Thus, the rotor completes a 360-degree circular motion.

[0048] Steps ① to ③ above complete one 180-degree rotation, completing one power supply cycle. Two power supply cycles, i.e., steps ① to ⑥, complete a 360-degree rotation of the rotor. This cycle repeats continuously, causing the motor rotor to rotate continuously.

[0049] If the power supply sequence in step ① is changed from windings LA and LC to windings LA and LB, the rotor's rotation direction will change from counterclockwise to clockwise.

[0050] If the phase voltage is a sine wave, this application is also applicable to permanent magnet synchronous motors. Similarly, this application proposes a new magnetic drive-repulsion drive mode, the principle of which is also applicable to permanent magnet motors such as stepper motors and servo motors. In addition, the principle of this application is also applicable to linear drive motion mechanisms.

[0051] 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 three-phase 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 first salient pole, a second salient pole, and a third salient pole that are radially and uniformly arranged around the inner ring of the annular silicon steel sheet. A first coil winding, a second coil winding, and a third coil winding are respectively wound on the first salient pole, the second salient pole, and the third salient pole. The rotor includes a rotatable magnetic ring located in the inner ring of the annular silicon steel sheet and a first magnet and a second magnet that are radially and uniformly arranged around the outer ring of the magnetic ring. When the first coil winding, the second coil winding, and the third coil winding are energized, they form a magnetic field with the gap between the first magnet and the second magnet. The magnetic field lines of the first coil winding, the second coil winding, and the third coil winding are all in a first direction, and the magnetic field lines of the first magnet and the second magnet are all in a second direction. The first direction and the second direction are the same so that the magnetic field generates a repulsive force to drive the rotor to rotate.

2. The single-pole three-phase brushless DC motor as described in claim 1, characterized in that: The first coil winding, the second coil winding, and the third coil winding are wound in the same direction, wherein, The first end of the first coil winding extends to connect to the first energized end, the first end of the second coil winding extends to connect to the second energized end, and the first end of the third coil winding extends to connect to the third energized end. The second ends of the first coil winding, the second end of the second coil winding, and the second end of the third coil winding are connected to each other.

3. The single-pole three-phase brushless DC motor as described in claim 2, characterized in that: The portion where the second end of the first coil winding, the second end of the second coil winding, and the second end of the third coil winding are connected to each other extends to the fourth energized end.

4. The single-pole three-phase brushless DC motor as described in claim 1, characterized in that: Hall effect magnetic induction signal sensors are embedded in the portions of the first salient pole, the second salient pole, and the third salient pole near the rotor.

5. The single-pole three-phase 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.

6. The single-pole three-phase brushless DC motor as described in claim 5, 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. The interior of the central shaft is a hollow cavity. The three-phase wire harness of the coil winding extends from inside the housing through the hollow cavity to the outside of the housing.

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