WO2020000667A1

WO2020000667A1 - Stator structure of motor, stator assembly structure, and motor

Info

Publication number: WO2020000667A1
Application number: PCT/CN2018/105274
Authority: WO
Inventors: 陶志杰; 吕锦贤; 张海宁
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2018-06-26
Filing date: 2018-09-12
Publication date: 2020-01-02
Also published as: CN208369342U; CN110896681A

Abstract

A stator structure of a motor, a stator assembly structure, and a motor. The motor comprises a stator structure and a rotor structure which rotates with respect to the stator structure, and the stator structure is connected to a circuit board. The stator structure comprises a coil winding (2); the coil winding (2) comprises an iron core (21) and a coil (22) wound on the iron core (21); the coil (22) is connected to the circuit board (4) by means of a plurality of pins (24); the circuit board (4) is a flexible circuit board. On this basis, the stator structure of the motor has a compact structure and facilitates assembly and welding of the motor, automation can more easily be achieved, stability and reliability of the stator structure of the motor are improved, and the efficiency and yield of production are improved.

Description

Stator structure, stator assembly structure of motor and motor

Technical field

Embodiments of the present invention relate to the technical field of motors, and in particular, to a stator structure, a stator assembly structure, and a motor using the stator assembly structure of a brushless DC motor.

Background technique

The current brushless DC motor is generally mainly composed of a stator structure, a rotor structure, and a circuit part. The stator structure includes a coil. After the coil is energized, the magnetic field generated by the permanent magnet (magnet) in the rotor structure is combined. The principle of force in a magnetic field, the rotor structure will generate rotational motion. The control part of the motor controls the parameters such as the speed and torque of the motor through the chip to control the voltage and current of the coil to the stator structure. The coil is usually connected to the control circuit through a circuit board, and then the stator structure and the circuit board are integrally mounted on the motor base.

FIG. 5 is an exploded perspective view of a conventional motor; FIG. 6 is an exploded perspective view of a rotor structure in FIG. 5.

As shown in FIG. 5 and FIG. 6, the conventional rotor structure is generally composed of components such as the rotating shaft 110, the yoke 120, the holder 130, the upper cover 140, and the magnet 30.

In addition, the existing stator structure usually includes a multi-phase coil winding 20 composed of an iron core and a coil. The coil winding 20 is connected to other circuit parts (for example, the circuit board 40) through an enameled wire to be energized, and is then assembled on the motor base 50 as a whole. on.

In the coil winding 20, the iron core is a magnetically conductive material with better performance. The coil is wound on the iron core by multiple layers of enameled wire. The wound wire is generally divided into three phases, each of which has an incoming line and an outgoing line. Six leads.

The six leads in the coil winding 20 need to be connected to the circuit board 40 in order to connect the control circuit. At present, the control circuit of the enameled wire connection of the brushless DC motor mainly adopts the following method: The circuit board 40 connected to the control circuit is located directly below the coil winding 20, and six pads are reserved on the circuit board 40 to correspond to the six enameled wires. Position it, and then manually solder the enameled wire to the corresponding pad with a soldering iron to form a conduction circuit. In addition, it is necessary to structurally support the coil winding 20 and the circuit board 40 by a plastic sheet 80. In addition, in order to ensure the normal rotation of the rotating shaft, an upper bearing 60 and a lower bearing 70 are respectively provided.

However, the existing stator assembly structure of the brushless motor requires manual welding. On the one hand, the welding yield is not high and the quality of the solder joint cannot be controlled; on the other hand, the manual operation is inefficient and cannot be automated. Assembly. In addition, the assembly process is prone to bad conditions such as wire breaks, short circuits, and incorrect contact; the entire winding structure is relatively loose, is not firmly connected, and is not stable enough.

In addition, with the above-mentioned stator assembly structure, for a PCB circuit board (hard circuit board), it is easy to cause disconnection, and for an FPC circuit board (flexible circuit board), deviation and deformation are more likely to occur.

In addition, the stator assembly requires a separate plastic sheet, which increases the number of parts and increases costs.

Summary of the invention

An embodiment of the present invention provides a stator structure of a motor. The motor includes a stator structure and a rotor structure rotating relative to the stator structure. The stator structure is connected to a circuit board. The stator structure includes a coil winding, and the coil winding includes An iron core and a coil wound on the iron core, the coil is connected to the circuit board through a plurality of pins, and the circuit board is a flexible circuit board.

Further, the surface of the iron core is covered with a plastic insulating layer.

Further, a plastic bottom is formed at the bottom of the core to extend to the circuit board side, the plastic bottom supports the core with respect to the circuit board, and the plastic bottom is further provided with a mounting portion for mounting the pin.

Further, each phase of the coil has two leads of a lead-in terminal and a lead-out terminal, and the two leads respectively correspond to a pair of the pins, and one end of the pins is connected to the leads of the coil. The other end of the pin is connected to a pad on the circuit board.

Further, a small hole for inserting the pin is formed in the mounting portion, and the pin passes through the small hole and is connected to the lead.

Further, a connection hole corresponding to the pin is formed on a pad of the electric wire board, and the other end of the pin is soldered to the connection hole of the pad to realize electrical connection with the circuit board.

An embodiment of the present invention provides a stator assembly structure, wherein the above-mentioned stator assembly structure includes the above-mentioned stator structure of a motor and a circuit board.

Further, the stator assembly structure further includes a motor base, and the circuit board is fixed on the motor base.

Further, a Hall sensor for detecting a rotation angle of the motor and a capacitor for filtering a current signal are formed on a surface of the circuit board opposite to the stator structure.

An embodiment of the present invention provides a motor, wherein the motor includes a rotor structure and the stator assembly structure described above.

Further, the rotor structure includes a molded body and a plurality of magnets embedded in the molded body for generating a magnetic field inside the motor. The molded body integrally has a rotating shaft rotating around a central axis of the motor, a yoke, and a plurality of the magnets. In the holder that maintains the positional relationship between them, the surface of the magnet is bonded to the inner peripheral side of the yoke.

In addition, the stator assembly structure of the motor according to the embodiment of the present invention greatly improves the assembly process of the existing motor, facilitates automatic welding and assembly, and can be widely used in the manufacture and assembly of brushless motors to improve production efficiency and welding reliability.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the technical solutions and advantages of the embodiments of the present invention, reference will now be made to the following description in conjunction with the accompanying drawings, in which:

1 is an exploded perspective view of a motor according to an embodiment of the present invention;

2 is a cross-sectional view of the motor in an assembled state corresponding to FIG. 1;

3 is a cross-sectional view of a rotor in an assembled state according to an embodiment of the present invention;

4 is an exploded perspective view of a stator assembly structure according to an embodiment of the present invention as viewed from the upper side;

5 is an exploded perspective view of a conventional motor;

FIG. 6 is an exploded perspective view of the rotor structure in FIG. 5.

Reference signs:

1-molded body of rotor structure, 11, 110-rotary shaft, 12, 120-yoke, 13, 130-retainer, 14, 140-upper cover, 2, 20-coil winding of stator structure, 21-iron core, 22-coil, 23-bottom, 24-pin (pin), 25-mounting section, 3, 30-magnet, 4, 40-circuit board, 41-pad, 42-hall sensor, 43-capacitor, 5, 50-motor base, 6, 60-up bearing, 7, 70-down bearing, 80-plastic sheet.

detailed description

In the following, the technical solutions of the embodiments of the present invention will be clearly and completely described with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of them. Based on the embodiments in the embodiments of the present invention, all other embodiments obtained by a person having ordinary skill in the art without making creative efforts belong to the protection scope of the embodiments of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art belonging to the embodiments of the present invention. The terms used in the description of the embodiments of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present invention.

The following describes some embodiments of the present invention in detail with reference to the drawings. Without conflict, the features in the embodiments described below can be combined with each other.

1 is an exploded perspective view of a motor according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of a motor corresponding to FIG. 1 in an assembled state; FIG. 3 is a cross-sectional view of a rotor structure in an assembled state according to an embodiment of the present invention; An exploded perspective view of a stator assembly structure according to an embodiment of the invention as viewed from the upper side.

The (inductive) brushless DC motor of the embodiment of the present invention generally includes a stator structure, a rotor structure that rotates relative to the stator structure, and a circuit part that energizes the stator structure (coil winding) to generate electromagnetic waves.

As shown in FIGS. 1 and 2, the rotor structure includes a molded body 1 and a magnet 3 embedded in the molded body 1 for generating a magnetic field inside the motor. The molded body 1 includes a rotating shaft 11 that rotates around a central axis of the motor, a yoke 12, a holder 13 that holds the magnet, and an upper cover that is connected to the yoke 12 and covers the magnet 3 together with the yoke 12. 14. When molding the molded body 1, the motor shaft 11 and the yoke 12 are first put into a mold, and the molded product having the shaft 11, the yoke 12, the holder 13, and the upper cover 14 is integrally formed by insert injection molding. The upper cover 14 and the holder 13 may be plastic components, and the motor shaft 11 and the yoke 12 may be metal components. In addition, the motor of this embodiment is further provided with an upper bearing 6 and a lower bearing 7 in order to ensure the normal rotation of the rotating shaft.

As shown in FIG. 2 and FIG. 3 together, in the rotor assembly state, the rotating shaft 11 rotates relative to the stator structure together with the entire molded body 1 and the magnet 3, and the holder 13 is located between the plurality of magnets 3 to hold a plurality of Positional relationship between magnets. The magnet 3 (for example, a tile-type magnet) is mounted on the inner side of the molded body 1 (that is, the inner ring of the yoke 12) by a surface mount method (SMT). The magnet 3 is mostly made of rare-earth permanent magnet materials with high coercive force and high magnetic permeability, such as neodymium iron boron, and generates a constant magnetic field inside the motor.

Hereinafter, a manufacturing process of a rotor structure of a motor according to an embodiment of the present invention will be described.

First, the motor shaft 11 and the yoke 12 are prepared in advance, wherein the motor shaft 11 is usually processed by turning, and the yoke 12 is usually processed by a stamping process;

Next, the prepared motor shaft 11 and yoke 12 are put into a mold, the mold is closed, and injection molding is performed. According to this, the upper cover 14 and the holder 13 are formed from the injected plastic, and the metal motor is also formed. The rotating shaft 11 and the yoke 12 are integrally formed (molded body 1);

Next, the obtained molded body 1 is put into a jig, and then the magnet 3 is bonded to the inside of the molded body 1 (yoke 12) through the surface of the jig;

This completes the assembly of the entire rotor.

According to the above rotor structure, an in-mold injection method is used to place a metal motor shaft and yoke into a mold, and the cage of the rotor structure, the shaft, and the yoke (and the upper cover) are integrally injection-molded by insert molding. Next, the rotor structure needs to be assembled by simply putting magnets in such a molded body. According to this, the materials and assembly of a single holder and the upper cover are omitted, the assembly is more convenient, automatic assembly can be realized, a large amount of labor can be saved, and manufacturing efficiency can be improved.

In addition, the cage, the rotating shaft, and the yoke are formed into a molded body, the structure is simple and compact, and the rotor assembly is more reliable. In addition, the cage is integrated with the shaft and the yoke, on the one hand, it can strengthen the cage to prevent it from being easily deformed, and on the other hand, it can prevent the cage from being caused by the shrinkage and deformation of the plastic, manufacturing tolerances and other reasons. The problem of inaccurate positioning can make the rotor more consistent.

As shown in FIG. 4, the stator assembly structure includes a stator structure (coil winding 2) and a circuit board 4.

The coil winding 2 of the stator structure is formed by winding a multilayer enameled wire (coil 22) on an iron core 21 (tooth portion). Taking a three-phase brushless DC motor as an example, the wound coil is divided into three phases, for example The coil has two leads at the incoming end and the outgoing end, respectively corresponding to a pair of pins. The three-phase coil has a total of six leads. The six leads are connected to the corresponding pads 41 of the circuit board 4 as a circuit portion through a plurality of pins 24 (for example, six pins).

While the surface of the iron core 21 is covered with a plastic insulating layer, a plastic bottom 23 is formed on the bottom of the iron core 21 and extends to the circuit board side. The plastic insulation layer plays a role of fixing the iron core 21 and isolating the iron core 21 from the circuit board 4. The plastic bottom 23 can play a fixed supporting role with respect to the circuit board 4. The plastic bottom 23 is also provided with a mounting for the pin 24.部 25。 25.

According to this, when positioning the coil winding 2 with respect to the circuit board 4, there is no need for a separate plastic sheet as in the prior art. Compared with the prior art, this kind of plastic core is covered with a plastic insulation layer. By setting the plastic bottom, the number of components to be assembled can be reduced, and the assembly is more convenient. Due to the tight covering, the stability is also higher.

In this embodiment, one end of the pin 24 is connected to the lead of the coil winding 2, and the other end is connected to the pad 41 on the circuit board 4, so as to achieve conduction between the coil winding 2 and the circuit board 4.

Specifically, as shown in FIG. 1, the mounting portion 25 of the plastic bottom portion 23 of the iron core 21 has six small holes. Pins 24 are inserted into the six small holes in the mounting portion 25, and the pin material can be a tin-plated copper-clad steel wire, which can play a role of conduction. In this embodiment, since the positions of the small holes on the mounting portion 25 are relatively fixed, during the assembly process of the stator assembly structure, the pins 24 can be inserted into the corresponding small holes through a special pin machine, which can effectively improve Productivity.

In addition, the method of inserting the coil 22 into the tin furnace and dipping tin between the inserted pin 24 and the lead of the enameled wire can be used to achieve conduction.

In addition, six pads 41 with connecting holes in the center are formed on the circuit board 4 and correspond to the six pins 24 on the coil 22 respectively. When the pins 24 are soldered to the connecting holes of the corresponding pads 41 on the circuit board 4 , Can realize the electrical connection between the lead and the circuit board 4.

In addition, as shown in FIG. 4, a side surface (upper surface) of the circuit board 4 opposite to the stator structure is also formed with a Hall sensor 42 and a capacitor 43, wherein the Hall sensor 42 is used to detect the motor rotation angle, and the capacitor 43 is used To filter the current signal.

Specifically, after the pins 24 are passed through the connection holes of the corresponding pads 41 on the circuit board 4, the welding of the pins 24 and the circuit board 4 is completed using an automatic spot welding machine, and batch welding can be achieved with high welding efficiency, and It can effectively avoid the problem of weak solder joints and has a high welding yield.

Moreover, during the above-mentioned automatic welding, workers can place the coil windings and circuit boards that need to be welded next, which can save time and improve assembly efficiency.

In this embodiment, the number of pins 24, small holes in the mounting portion 25, and the number of connection holes of the pad 41 can be determined according to the type of the motor, such as a three-phase brushless DC motor, pins 24, small holes, and connection holes. The numbers are six, of which six pins 24 correspond to the incoming end and the outgoing end of a phase circuit in two groups.

In this embodiment, as shown in FIGS. 1 and 4, the stator assembly structure further includes a motor base 5, in which the circuit board 4 is fixed on the motor base 5. Based on the assembled stator assembly structure, it can be further assembled by automation. The method assembles the stator assembly structure with other components such as a rotor component to obtain a motor.

The following describes the welding and assembly methods of the brushless DC motor windings in the embodiments of the present invention:

First, the surface insulation layer of the iron core 21 adopts an injection molding process. By coating a layer of plastic insulation on the surface of the iron core 21, a fixed plastic bottom 23 is formed on the bottom of the iron core 21, and the plastic bottom 23 is installed together. Six small holes are formed in the portion 25;

Secondly, after the iron core is injection-molded, the pins 24 are inserted into the six small holes of the mounting portion 25 by the pin insertion machine;

After inserting the pin 24, put the iron core 21 on the winding machine to start winding. Each phase of the coil is wound on the corresponding end of the pin 24 for a few turns, and then the slot wire of the phase is wound. After slotting the wire, make a few turns on the corresponding pin 24 at the outlet end, repeating the action of each phase in turn until all the coils 22 have been wound;

The coil 22 after winding is put into a tin furnace to immerse tin, so that the leads of the three-phase (six-in-all) enameled wires and the corresponding pins 24 of the emissive wire are conducted;

Then, put the coil 22 soaked in the tin into the jig, and then place the circuit board 4 on the jig. The six pins 24 of the coil 22 are aligned with the six connection holes of the pad 41 of the circuit board 4, respectively. ;

Finally, place the fixture on the automatic spot welder. After setting the position, start the spot welder and start automatic welding. After the welding is completed, the internal resistance, interturn, insulation, and pressure resistance tests are performed after washing and brushing the insulation paint. In this way, the coil winding 2 is assembled.

According to the above-mentioned stator structure and welding process, since the flexible connection between the coil and the circuit board is not as fragile as in the prior art, the embodiment of the present invention adopts a dead fixed method, the structure is reliable, and it can be freely grasped and placed by a robot . For this reason, after the coil winding is completed, it can be clamped by a mechanical hand to complete the process of assembling the coil winding to the motor base.

In addition, the introduction of a spot welder to automatically spot-weld the pins to the circuit board has stable and reliable solder joints and high welding efficiency. Therefore, the assembly structure is simple and convenient, automated assembly can be realized, a large amount of labor can be saved, and assembly efficiency can be improved.

In this embodiment, the circuit board 4 may be an FPC board. Because the FPC board can be bent freely compared to using a PCB board, the wiring is easier. In addition, the FPC circuit board itself has flexibility. Compared with the prior art, the above-mentioned stator assembly structure can effectively avoid false welding, false welding, and weak solder joints, and has a high welding yield.

In the above embodiment of the embodiment of the present invention, a three-phase brushless DC motor (six lead wires) is used as an example for description. However, those skilled in the art can certainly understand that the embodiment of the present invention can also be applied to other types of On the motor.

In addition, a person of ordinary skill in the art should recognize that the above embodiments are only used to describe the embodiments of the present invention, and are not intended to limit the embodiments of the present invention, as long as they are within the essential spirit of the embodiments of the present invention. The appropriate changes and transformations to the above embodiments all fall within the scope of protection of the embodiments of the present invention.

Claims

A stator structure of a motor includes a stator structure and a rotor structure rotating relative to the stator structure. The stator structure is connected with a circuit board (4), and is characterized by:

The stator structure includes a coil winding (2), and the coil winding (2) includes an iron core (21) and a coil (22) wound on the iron core (21),

The coil (22) is connected to the circuit board (4) through a plurality of pins (24),

The circuit board (4) is a flexible circuit board.
The stator structure of a motor according to claim 1, characterized in that:

A plastic insulation layer is coated on the surface of the iron core (21).
The stator structure of a motor according to claim 2, wherein:

A plastic bottom (23) is formed at the bottom of the iron core (21) and extends to the circuit board (4) side. The plastic bottom (23) supports the iron core relative to the circuit board (4). The plastic bottom (23) is further provided with a mounting portion (25) for mounting the pin (24).
The stator structure of a motor according to claim 3, wherein:

Each phase of the coil (22) has two lead wires of an incoming end and an outgoing end. The two leads respectively correspond to a pair of the pins (24), and one end of the pins (24) and The leads of the coil (22) are connected, and the other end of the pin (24) is connected to a pad (41) on the circuit board (4).
The stator structure of a motor according to claim 4, characterized in that:

A small hole for inserting the pin (24) is formed in the mounting portion (25), and the pin (24) passes through the small hole and is connected to the lead.
The stator structure of a motor according to claim 4, characterized in that:

A pad (41) on the electric wire board (4) is formed with a connection hole corresponding to the pin (24), and the other end of the pin (24) is soldered to the pad (41). The connection hole realizes electrical connection with the circuit board (4).
A stator assembly structure, a stator assembly structure, characterized in that the stator assembly structure includes a stator structure of a motor and a circuit board, and a stator structure of the motor includes a stator structure and a rotor structure rotating relative to the stator structure. The stator structure is connected to the circuit board (4), which is characterized in that:

The stator structure includes a coil winding (2), and the coil winding (2) includes an iron core (21) and a coil (22) wound on the iron core (21),

The coil (22) is connected to the circuit board (4) through a plurality of pins (24),

The circuit board (4) is a flexible circuit board.
The stator assembly structure according to claim 7, wherein a surface of the iron core (21) is covered with a plastic insulating layer.
The stator assembly structure according to claim 8, characterized in that a plastic bottom (23) is formed at the bottom of the iron core (21) to the side of the circuit board (4), and the plastic bottom (23) ) The iron core is supported relative to the circuit board (4), and the plastic bottom (23) is further provided with a mounting portion (25) for mounting the pin (24).
The stator assembling structure according to claim 9, characterized in that each phase of the coil (22) has two lead wires of an incoming end and an outgoing end, the two leads and a pair of the pins (24) ) Respectively, one end of the pin (24) is connected to the lead of the coil (22), and the other end of the pin (24) is connected to a pad on the circuit board (4) (41) Connected.
The stator assembly structure according to claim 10, wherein a small hole for inserting the pin (24) is formed in the mounting portion (25), and the pin (24) passes through the small A hole is connected to the lead.
The stator assembly structure according to claim 10, characterized in that the pad (41) on the electric wire plate (4) is formed with a connection hole corresponding to the pin (24), and the pin (24) The other end of) is soldered to the connection hole of the pad (41) to achieve electrical connection with the circuit board (4).
The stator assembly structure according to any one of claims 7 to 12, wherein the stator assembly structure further comprises a motor base (5), and the circuit board (4) is fixed on the motor base (5) .
The stator assembly structure according to claim 12 or 13, wherein:

A Hall sensor (42) for detecting a rotation angle of the motor and a capacitor (43) for filtering a current signal are also formed on a surface of the circuit board (4) opposite to the stator structure.
A motor characterized in that the motor includes a rotor structure and a stator assembly structure, wherein the stator assembly structure includes a stator structure and a circuit board of the motor, and the stator structure of the motor includes a stator structure And a rotor structure that rotates with respect to a stator structure, the stator structure is connected with a circuit board (4), and is characterized by:

The stator structure includes a coil winding (2), and the coil winding (2) includes an iron core (21) and a coil (22) wound on the iron core (21),

The coil (22) is connected to the circuit board (4) through a plurality of pins (24),

The circuit board (4) is a flexible circuit board.
The motor according to claim 15, characterized in that a surface of the iron core (21) is covered with a plastic insulating layer.
The motor according to claim 16, characterized in that a plastic bottom (23) is formed at the bottom of the iron core (21) to extend to the circuit board (4) side, and the plastic bottom (23) is opposite to The circuit board (4) supports the iron core, and the plastic bottom (23) is further provided with a mounting portion (25) for mounting the pin (24).
The electric machine according to claim 17, characterized in that each phase of the coil (22) has two lead wires at the lead-in end and the lead-out end, and the two leads are respectively separated from a pair of the pin (24). Correspondingly, one end of the pin (24) is connected to the lead of the coil (22), and the other end of the pin (24) is connected to a pad (41) on the circuit board (4). ) Are connected.
The motor according to claim 18, wherein a small hole for inserting the pin (24) is formed in the mounting portion (25), and the pin (24) passes through the small hole and Connected to the lead.
The motor according to claim 18, wherein a connection hole corresponding to the pin (24) is formed on a pad (41) on the electric wire plate (4), and the pin (24) The other end is soldered to the connection hole of the pad (41) to achieve electrical connection with the circuit board (4).
The motor according to any one of claims 15 to 18, wherein the stator assembly structure further comprises a motor base (5), and the circuit board (4) is fixed on the motor base (5).
The motor according to claim 20 or 21, wherein a surface of a side of the circuit board (4) opposite to the stator structure is further formed with a Hall sensor (42) for detecting a rotation angle of the motor and Capacitor (43) to filter the current signal.
The electric machine according to any one of claims 15 to 22, wherein:

The rotor structure includes a molded body (1) and a plurality of magnets (3) embedded in the molded body (1) for generating a magnetic field inside the motor,

The molded body (1) is integrally provided with a rotating shaft (11) rotating around a central axis of the motor, a yoke (12), and a holder (13) for maintaining a positional relationship between the plurality of magnets (3). ,

The surface of the magnet (3) is bonded to the inner peripheral side of the yoke (12).