CN110896681A

CN110896681A - Stator structure of motor, stator assembly structure and motor

Info

Publication number: CN110896681A
Application number: CN201880015438.3A
Authority: CN
Inventors: 陶志杰; 吕锦贤; 张海宁
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2018-06-26
Filing date: 2018-09-12
Publication date: 2020-03-20
Also published as: CN208369342U; WO2020000667A1

Abstract

A motor comprises a stator structure and a rotor structure rotating relative to the stator structure, wherein the stator structure is connected with 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 with a circuit board (4) through a plurality of contact pins (24), and the circuit board (4) is a flexible circuit board. Therefore, the stator structure of the motor is compact in structure, convenient for motor assembling and welding, easy to realize automation, capable of improving stability and reliability of the motor stator structure and capable of improving production efficiency and yield.

Description

Stator structure of motor, stator assembly structure and motor

Technical Field

The embodiment of the invention relates to the technical field of motors, in particular to a stator structure and a stator assembly structure of a brushless direct current motor and a motor adopting the stator assembly structure.

Background

The current brushless direct current motor is generally mainly composed of a stator structure, a rotor structure and a circuit part, wherein the stator structure comprises a coil, after the coil is electrified, the magnetic field generated by a permanent magnet (magnet) in the rotor structure is combined, according to the stress principle of an electrified conductor in the magnetic field, the rotor structure generates rotary motion, and a control part of the motor controls parameters such as voltage and current of the coil which is given to the stator structure through a chip to realize the regulation and control of the parameters such as the rotating speed, the torque and the like of the motor, so the coil of the stator structure is generally connected to the control circuit through a circuit board, and then the stator structure and the circuit board are integrally arranged on a motor base.

FIG. 5 is an exploded perspective view of a prior art motor; fig. 6 is an exploded perspective view of the rotor structure of fig. 5.

As shown in fig. 5 and 6, a conventional rotor structure is generally configured by assembling components such as a rotating shaft 110, a yoke 120, a holder 130, an upper cover 140, and a magnet 30.

In addition, the conventional stator structure generally includes a multi-phase coil winding 20 composed of an iron core and a coil, and the coil winding 20 is connected to other circuit parts (for example, a circuit board 40) through an enamel wire to be energized and is integrally assembled on the motor base 50.

In the coil winding 20, the iron core is a magnetic conductive material with good performance, the coil is formed by winding a plurality of layers of enameled wires on the iron core, the wound wires are generally divided into three phases, each of the three phases has an incoming wire and an outgoing wire, and the total number of the three phases is six lead wires.

Six leads in the coil winding 20 need to be in electrical communication with the circuit board 40 for connection to the control circuitry. At present, an enameled wire connection control circuit of a brushless direct current motor mainly adopts the following mode: the circuit board 40 connected with the control circuit is located under the coil winding 20, six bonding pads are reserved on the circuit board 40 to correspond to six enameled wires, the jig is used for assisting positioning, and then the enameled wires are welded to the corresponding bonding pads by manually taking an iron to form a conducting circuit. In addition, it is structurally necessary to support the coil windings 20 and press the circuit board 40 by the 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, in the conventional stator assembly structure of the brushless motor, manual welding operation is required, so that on one hand, the welding yield is not high, and the quality of welding spots cannot be controlled; on the other hand, manual work is inefficient and automated assembly cannot be achieved. In addition, the assembly process is easy to have the bad conditions of disconnection, short circuit, error contact and the like; the whole winding structure is loose, is not firmly connected and is not stable enough.

In addition, with the stator assembly structure, a PCB (hard circuit board) is likely to be broken, and a FPC (flexible circuit board) is more likely to be deviated or deformed.

In addition, the stator assembly structure needs to be additionally provided with a separate plastic sheet, and accordingly, the number of parts is increased, and the cost is also increased.

Disclosure of Invention

The embodiment of the invention provides a stator structure of a motor, the motor comprises a stator structure and a rotor structure rotating relative to the stator structure, the stator structure is connected with a circuit board, wherein: the stator structure comprises a coil winding, the coil winding comprises an iron core and a coil wound on the iron core, the coil is connected with the circuit board through a plurality of contact pins, and the circuit board is a flexible circuit board.

Furthermore, the surface of the iron core is coated with a plastic insulating layer.

Furthermore, a plastic bottom is formed by extending the bottom of the iron core to one side of the circuit board, the iron core is supported by the plastic bottom relative to the circuit board, and a mounting part for mounting the contact pin is further arranged on the plastic bottom.

Further, each phase of the coil has two leads of a wire inlet end and a wire outlet end, the two leads correspond to a pair of the pins, one end of each of the pins is connected to the lead of the coil, and the other end of each of the pins is connected to a pad on the circuit board.

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

Furthermore, the pad on the electric wire board is formed with a connecting hole corresponding to the pin, and the other end of the pin is welded to the connecting hole of the pad to realize the electric connection with the circuit board.

The embodiment of the invention provides a stator assembly structure, wherein: the stator assembly structure comprises the stator structure of the motor and a circuit board.

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

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

The embodiment of the invention provides a motor, wherein the motor comprises a rotor structure and the stator assembly structure.

Further, the rotor structure includes a molded body and a plurality of magnets embedded in the molded body to generate a magnetic field in the motor, the molded body integrally includes a rotating shaft that rotates around a central axis of the motor, a yoke, and a holder that holds a positional relationship between the plurality of magnets, and a surface of the magnet is bonded to an inner peripheral side of the yoke.

In addition, according to the stator assembly structure of the motor provided by the embodiment of the invention, the assembly process of the existing motor is greatly improved, the automatic welding and assembly are convenient to realize, the stator assembly structure can be widely applied to the manufacturing and assembly of the brushless motor, and the production efficiency and the welding reliability are improved.

Drawings

For a more complete understanding of the technical solutions of the embodiments of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

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

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

fig. 3 is a sectional view of the rotor of the embodiment of the present invention in an assembled state;

fig. 4 is an exploded perspective view of the stator assembly structure of the embodiment of the invention, viewed from the upper side;

FIG. 5 is an exploded perspective view of a prior art motor;

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

Reference numerals:

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

Detailed Description

The technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without any creative efforts shall fall within 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 to which embodiments of the present invention belong. The terminology used herein in the description of the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the invention.

Some embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Features in the embodiments described below may be combined with each other without conflict.

Fig. 1 is an exploded perspective view of a motor according to an embodiment of the present invention; fig. 2 is a sectional view of the motor corresponding to fig. 1 in an assembled state; FIG. 3 is a sectional view of the rotor structure of the embodiment of the present invention in an assembled state; fig. 4 is an exploded perspective view of the stator assembly structure of the embodiment of the present invention, viewed from the upper side.

A (inductive) brushless dc motor according to an embodiment of the invention typically comprises a stator structure, a rotor structure rotating relative to the stator structure, and a circuit portion for energizing the stator structure (coil windings) to generate electromagnetic fields.

As shown in fig. 1 and 2, the rotor structure includes a molded body 1 and a magnet 3 embedded inside the molded body 1 for generating a magnetic field inside the motor. The molded body 1 integrally includes a rotating shaft 11 that rotates around the central axis of the motor, a yoke 12, a holder 13 that holds the magnet, and an upper cover 14 that is connected to the yoke 12 and covers the magnet 3 together with the yoke 12. When the molded body 1 is molded, the motor shaft 11 and the yoke 12 are first placed in a mold, and a molded article having the shaft 11, the yoke 12, the holder 13, and the upper cover 14 is integrally molded 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 the 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 3, in the rotor assembled state, the rotating shaft 11 rotates together with the entire molded body 1 and the magnets 3 with respect to the stator structure, and the holder 13 is positioned between the plurality of magnets 3 to hold the positional relationship between the plurality of magnets. The magnet 3 (e.g., a tile-shaped magnet) is mounted on the inner side of the molding body 1 (i.e., the inner ring of the yoke 12) by a Surface Mount Technology (SMT). The magnet 3 is made of rare earth permanent magnet materials with high coercive force and high permeability magnetic induction density such as neodymium iron boron, and a constant magnetic field is generated inside the motor.

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

Firstly, a motor rotating shaft 11 and a magnetic yoke 12 are prepared in advance, wherein the motor rotating shaft 11 is usually formed by turning, and the magnetic yoke 12 is usually formed by stamping;

next, the prepared motor shaft 11 and yoke 12 are placed in a mold, and mold closing and injection molding are performed, whereby the upper cover 14 and holder 13 are molded by injected plastic, and the metal motor shaft 11 and yoke 12 are also formed integrally (molded body 1);

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

thus, the assembly of the entire rotor is completed.

According to the rotor structure, the mode of in-mold injection molding is adopted, the motor rotating shaft and the magnetic yoke which are made of metal materials are placed in a mold, the retainer, the rotating shaft and the magnetic yoke (and the upper cover) of the rotor structure are integrally injection molded through insert molding, and then the rotor structure can be assembled only by installing the magnet in the molded body. In view of the above, the material and the equipment of single holder and upper cover have been saved, and the assembly is more convenient, can realize automatic equipment, can save a large amount of manual works, promote manufacturing efficiency.

In addition, the retainer, the rotating shaft and the magnetic yoke are formed into a forming body, so that the structure is simple and compact, and the rotor assembly is more reliable. And the retainer is integrated with the rotating shaft and the magnetic yoke, so that the retainer can be enhanced to be not easy to deform, the problem that the retainer is not accurately positioned with the rotating shaft and the magnetic yoke due to plastic shrinkage deformation, manufacturing tolerance and the like can be solved, and the consistency of the rotor can be better.

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 plurality of layers of enameled wires (coils 22) around an iron core 21 (tooth portion), and, taking a three-phase brushless dc motor as an example, the wound coils are divided into three phases, each phase coil has two leads of a lead-in end and a lead-out end, corresponding to a pair of pins, respectively, and the three-phase coils have a total of six leads. The six leads are connected to corresponding pads 41 of the circuit board 4 as a circuit portion through a plurality of pins 24 (for example, six pins), respectively.

The surface of the iron core 21 is coated with a plastic insulating layer, and a plastic bottom 23 is formed at the bottom of the iron core 21 and extends towards one side of the circuit board. The plastic insulating layer plays a role in fixing the iron core 21 and isolating the iron core 21 from the circuit board 4, the plastic bottom 23 can play a role in fixing and supporting the circuit board 4, and the plastic bottom 23 is further provided with a mounting part 25 for mounting the contact pin 24.

In view of the above, when fixing a position coil winding 2 for circuit board 4, need not to need an independent plastic piece like prior art in addition, compare in prior art, this kind of mode of cladding plastic insulating layer in order to set up the plastic bottom on iron core 21 can reduce the part of equipment, and the equipment is more convenient, because closely the cladding, stability is also higher.

In the present 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, six small holes are formed on the mounting portion 25 of the plastic bottom 23 of the iron core 21. Inserting pins 24 are inserted into six small holes in the mounting part 25, and the inserting pins can be made of tinned copper clad steel wires and can play a role in conducting. In this embodiment, since the positions of the small holes on the mounting portion 25 are relatively fixed, the pins 24 can be inserted into the corresponding small holes by a special pin inserting machine during the assembling process of the stator assembling structure, and the production efficiency can be effectively improved.

Moreover, the coil 22 may be placed in a tin furnace for immersion tin to achieve conduction between the inserted contact pin 24 and the lead wire of the enamel wire.

In addition, six pads 41 with connecting holes at the centers are formed on the circuit board 4 and respectively correspond to the six pins 24 on the coil 22, and when the pins 24 are welded to the connecting holes of the corresponding pads 41 on the circuit board 4, the leads can be electrically connected with the circuit board 4.

In addition, as shown in fig. 4, a hall sensor 42 and a capacitor 43 are formed on a surface (upper surface) of the circuit board 4 opposite to the stator structure, wherein the hall sensor 42 is used for detecting a rotation angle of the motor, and the capacitor 43 is used for filtering a current signal.

Specifically, after the contact pin 24 passes through the connecting hole of the corresponding pad 41 on the circuit board 4, the contact pin 24 and the circuit board 4 are welded by using an automatic spot welding machine, batch welding can be realized, welding efficiency is high, the problem of infirm welding points can be effectively avoided, and higher welding yield is achieved.

Moreover, during the automatic welding, workers can place the coil winding, the circuit board and the like which need to be welded next, so that time can be saved, and the assembly efficiency is improved.

In this embodiment, the number of the pins 24, the holes on the mounting portion 25, and the connecting holes of the pad 41 may be determined according to the type of the motor, for example, a three-phase brushless dc motor, and the number of the pins 24, the holes, and the connecting holes are six, where two of the six pins 24 are a group corresponding to the wire inlet end and the wire outlet end of the one-phase circuit.

In this embodiment, as shown in fig. 1 and 4, the stator assembly structure further includes a motor base 5, wherein the circuit board 4 is fixed on the motor base 5, and based on the assembled stator assembly structure, the stator assembly structure can be further assembled with other components, such as a rotor assembly, in an automated assembly manner to obtain the motor.

The following describes the welding and assembling method of the brushless dc motor winding according to the embodiment of the present invention:

firstly, the surface insulating layer of the iron core 21 adopts an injection molding process, a layer of plastic insulation is coated on the surface of the iron core 21, a plastic bottom 23 for fixing is formed at the bottom of the iron core 21, and six small holes are formed on an installation part 25 of the plastic bottom 23;

secondly, inserting a contact pin 24 in six small holes of the mounting part 25 by a contact pin machine after the iron core is molded;

after the insertion of the contact pin 24 is completed, the iron core 21 is placed on a winding machine to start winding, each phase of coil is wound on the corresponding contact pin 24 at the incoming line end for several times, then the slot line of the phase is wound, and after the normal slot line is wound, the coil is wound on the corresponding contact pin 24 at the outgoing line end for several times, and the actions of each phase are repeated in sequence until all the coils 22 are wound;

placing the coil 22 after the wire winding into a tin furnace for tin immersion, and conducting leads of the inlet wire end and the outlet wire end of the three phases (six in total) of the enameled wire with the corresponding contact pins 24;

then, the coil 22 soaked with tin is placed in the jig, the circuit board 4 is placed on the jig, and six pins 24 of the coil 22 are respectively aligned with six connecting holes of the bonding pad 41 of the circuit board 4;

and finally, placing the jig on an automatic spot welding machine, starting the spot welding machine after positioning, starting automatic welding, and carrying out internal resistance, turn-to-turn, insulation and voltage resistance tests after plate washing and insulating paint brushing after welding is finished, so that the coil winding 2 is assembled.

According to the stator structure and the welding process, because the coil and the circuit board are not fragile due to flexible connection in the prior art, the stator structure and the welding process are reliable in structure due to the fact that a dead fixing mode is adopted, and the stator structure and the welding process can be grabbed and placed at will by a manipulator. Therefore, after the coil winding is finished, the coil winding can be clamped by a manipulator, and the process of assembling the coil winding on the motor base is completed.

Moreover, a spot welding machine is introduced to automatically spot-weld the contact pin on the circuit board, the welding spot is stable and reliable, and the welding efficiency is also high, so that the assembling structure is simple and convenient, automatic assembling can be realized, a large amount of labor can be saved, and the assembling efficiency is improved.

In the present embodiment, the circuit board 4 may be an FPC board. Because the FPC board can be bent at will compared with a PCB board, wiring is easier. Moreover, the FPC circuit board has flexibility, and the stator assembly structure can effectively avoid the conditions of insufficient solder, false solder, infirm solder joint and the like and has higher welding yield compared with the prior art.

In the above embodiments of the present invention, the three-phase brushless dc motor (six leads) is taken as an example for description, but it is obvious to those skilled in the art that the embodiments of the present invention can also be applied to other types of motors.

In addition, those skilled in the art should recognize that the foregoing embodiments are illustrative of the present invention, and are not meant to be limiting, and that various changes and modifications can be made without departing from the spirit and scope of the embodiments.

Claims

1. A stator structure of an electric machine, the electric machine comprising a stator structure and a rotor structure rotating in relation to the stator structure, the stator structure being connected to a circuit board (4), characterized in that:

the stator structure comprises a coil winding (2), the coil winding (2) comprises a core (21) and a coil (22) wound on the 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.

2. The stator structure of an electric machine according to claim 1, characterized in that:

the surface of the iron core (21) is coated with a plastic insulating layer.

3. The stator structure of an electric machine according to claim 2, characterized in that:

the bottom of iron core (21) to circuit board (4) one side is extended and is formed with plastic bottom (23), plastic bottom (23) for circuit board (4) support the iron core, still be equipped with on plastic bottom (23) and be used for the installation department (25) of contact pin (24).

4. The stator structure of an electric machine according to claim 3, characterized in that:

each phase of the coil (22) is provided with two lead wires of a wire inlet end and a wire outlet end, the two lead wires correspond to a pair of the contact pins (24), one end of each contact pin (24) is connected with the lead wire of the coil (22), and the other end of each contact pin (24) is connected with a bonding pad (41) on the circuit board (4).

5. The stator structure of an electric machine according to claim 4, characterized in that:

the mounting part (25) is formed with a small hole for inserting the pin (24), and the pin (24) passes through the small hole and is connected with the lead.

6. The stator structure of an electric machine according to claim 4, characterized in that:

the pad (41) on the electric wire plate (4) is formed with a connecting hole corresponding to the pin (24), and the other end of the pin (24) is soldered to the connecting hole of the pad (41) to realize the electric connection with the circuit board (4).

7. The utility model provides a stator package assembly, its characterized in that, stator package assembly includes the stator structure and the circuit board of motor, the stator structure of motor, its characterized in that includes stator structure and the rotor structure that relative stator structure carries out the rotation, stator structure is connected its characterized in that with circuit board (4):

the circuit board (4) is a flexible circuit board.

8. The stator assembly structure according to claim 7, wherein a plastic insulating layer is coated on the surface of the core (21).

9. The stator assembly structure according to claim 8, wherein a plastic bottom (23) is formed at the bottom of the iron core (21) and extends towards one side of the circuit board (4), the plastic bottom (23) supports the iron core relative to the circuit board (4), and a mounting portion (25) for mounting the contact pin (24) is further arranged on the plastic bottom (23).

10. A stator assembly structure according to claim 9, wherein each phase of the coil (22) has two lead wires of a lead-in end and a lead-out end, the two lead wires correspond to a pair of the contact pins (24), one end of the contact pin (24) is connected to the lead wire of the coil (22), and the other end of the contact pin (24) is connected to a land (41) on the circuit board (4).

11. The stator assembly structure according to claim 10, wherein the mounting portion (25) is formed with a small hole for inserting the pin (24), and the pin (24) is connected to the lead through the small hole.

12. The stator assembly structure according to claim 10, wherein a land (41) on the electric wire plate (4) is formed with a connection hole corresponding to the pin (24), and the other end of the pin (24) is soldered to the connection hole of the land (41) to achieve the electrical connection with the circuit board (4).

13. A stator assembly according to any one of claims 7 to 12, further comprising a motor base (5), wherein the circuit board (4) is fixed to the motor base (5).

14. The stator assembly structure according to claim 12 or 13, wherein:

and a Hall sensor (42) for detecting the rotation angle of the motor and a capacitor (43) for filtering a current signal are further formed on the surface of one side, opposite to the stator structure, of the circuit board (4).

15. An electric machine characterized by: the motor includes rotor structure and stator package assembly, its characterized in that, stator package assembly includes the stator structure and the circuit board of motor, the stator structure of motor, its characterized in that includes stator structure and the relative stator structure rotor structure who carries out the rotation, stator structure is connected its characterized in that with circuit board (4):

the circuit board (4) is a flexible circuit board.

16. The electrical machine according to claim 15, characterized in that the surface of the core (21) is coated with a plastic insulating layer.

17. The motor according to claim 16, wherein a plastic bottom (23) is formed at the bottom of the iron core (21) and extends towards one side of the circuit board (4), the plastic bottom (23) supports the iron core relative to the circuit board (4), and a mounting portion (25) for mounting the contact pin (24) is further arranged on the plastic bottom (23).

18. An electric machine as claimed in claim 17, characterized in that each phase of the coil (22) has two leads, one in line and one out line, respectively, corresponding to a pair of said pins (24), one end of said pin (24) being connected to said lead of the coil (22) and the other end of said pin (24) being connected to a pad (41) on the circuit board (4).

19. The motor according to claim 18, wherein the mounting portion (25) is formed with an aperture for inserting the pin (24), and the pin (24) is connected to the lead through the aperture.

20. The machine according to claim 18, characterized in that the pads (41) on the electric wire plate (4) are formed with connection holes corresponding to the pins (24), the other ends of the pins (24) being soldered to the connection holes of the pads (41) to achieve the electrical connection with the circuit board (4).

21. The machine according to any of claims 15 to 18, wherein the stator assembly further comprises a machine base (5), the circuit board (4) being fixed to the machine base (5).

22. The machine according to claim 20 or 21, characterized in that the circuit board (4) is also formed with a hall sensor (42) for detecting the angle of rotation of the machine and a capacitor (43) for filtering the current signal on the surface on the side opposite to the stator structure.

23. The electric machine of any one of claims 15 to 22, wherein:

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

the molded body (1) integrally includes a rotating shaft (11) rotating around the central axis of the motor, a yoke (12), and a holder (13) for holding the 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).