CN110896682A

CN110896682A - Rotor structure of motor and motor

Info

Publication number: CN110896682A
Application number: CN201880017037.1A
Authority: CN
Inventors: 陶志杰; 颜学力; 张雷雷
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2018-06-26
Filing date: 2018-09-19
Publication date: 2020-03-20
Also published as: CN208272734U; WO2020000698A1

Abstract

The motor comprises a stator structure and a rotor structure rotating relative to the stator structure, the rotor structure comprises a forming body (1) and a plurality of magnets (3) embedded in the forming body (1) and used for generating a magnetic field in the motor, the forming body (1) is integrally provided with a rotating shaft (11) rotating around a central shaft of the motor, a magnetic yoke (12) and a retainer (13) for retaining the position relation among the magnets (3), and the surfaces of the magnets (3) are attached to the inner peripheral side of the magnetic yoke (12). Therefore, the rotor structure of the motor is compact in structure, convenient for motor assembly, easy to realize automation, capable of improving stability and reliability of the rotor structure of the motor and capable of improving production efficiency and yield.

Description

Rotor structure of motor and motor

Technical Field

The embodiment of the invention relates to the technical field of motors, in particular to a motor rotor structure of a brushless direct current motor and a motor adopting the rotor 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 the 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, 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 energized by connecting an enamel wire to other circuit parts (e.g., a circuit board 40) and is integrally assembled to a 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. The substrate of the circuit board may be a PCB (rigid circuit board) or an FPC (flexible circuit board). 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.

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

However, for the existing rotor structure, if the annular magnet is adopted, the magnetic field intensity is not enough, and the output requirement of the motor cannot be met; even if the tile-shaped magnet is adopted and fixed by using the independent plastic retainer, the materials of the upper cover and the retainer and redundant assembly processes are increased virtually, so that the production efficiency is low; in addition, the assembly of a single retainer has uncertainty, the position of the assembled magnet cannot be well controlled, and the consistency of rotor mass production is not facilitated.

Disclosure of Invention

In view of this, embodiments of the present invention are directed to at least one of the technical problems in the prior art, and provide a novel rotor structure of a motor and a motor having the same, which are compact in structure, convenient for motor assembly, easier to implement automation, and capable of improving stability and reliability of the rotor structure of the motor, and improving production efficiency and yield.

The invention provides a rotor structure of a motor, the motor comprises a stator structure and a rotor structure rotating relative to the stator structure, wherein the rotor structure comprises a molded body and a plurality of magnets embedded in the molded body and used for generating a magnetic field in the motor, the molded body integrally comprises a rotating shaft rotating around a central shaft of the motor, a magnetic yoke and a retainer for maintaining the position relation between the magnets, and the surface of the magnet is attached to the inner peripheral side of the magnetic yoke.

Further, the molded body may further integrally include an upper cover coupled to the yoke to cover the magnet together with the yoke.

Further, the rotating shaft and the yoke are metal members.

Further, the holder and the upper cover are plastic members.

Further, the rotating shaft, the yoke, the holder, and the upper cover are integrally formed by insert molding.

Further, the magnet is a tile-shaped magnet.

Further, the holder is positioned between the plurality of magnets to hold a positional relationship between the plurality of magnets.

In addition, an embodiment of the present invention further provides a motor, wherein: the motor comprises a stator structure and a rotor structure of the motor.

Further, the stator structure is connected with a circuit board, the stator structure comprises a coil winding, the coil winding comprises an iron core and a coil wound on the iron core, and the coil is connected with the circuit board through a plurality of contact pins.

Furthermore, a small hole for inserting the pin is formed on the plastic bottom of the iron core, one end of the pin passes through the small hole and is connected with the coil, a connecting hole corresponding to the pin is formed on the pad on the circuit board, and the other end of the pin is welded to the connecting hole of the pad and is electrically connected with the circuit board.

According to the rotor structure of the motor, the performance and the assembly process of the motor are greatly improved, the rotor structure can be widely applied to manufacturing and assembling of the motor, and the production efficiency is 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, 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 the mounting part 25;

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 a PCB or an FPC. Due to the adoption of an automatic welding dead fixing mode, the PCB is not easy to break, and the FPC is not easy to deviate and deform. Especially, for the FPC circuit board, its own has the compliance, adopts above-mentioned stator package assembly, for prior art, more can effectively avoid the condition such as rosin joint, false solder, solder joint are not firm, has higher welding yield. In a preferred embodiment, the circuit board 4 is an FPC, which can be bent freely, so that the wiring is easier.

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 rotor structure of an electric machine, the electric machine comprising a stator structure and a rotor structure rotating relative to the stator structure, characterized in that:

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).

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

the molded body (1) further integrally has an upper cover (14) connected to the yoke (12) and covering the magnet (3) together with the yoke (12).

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

the rotating shaft (11) and the yoke (12) are metal parts.

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

the holder (13) and the upper cover (14) are plastic parts.

5. The rotor structure of an electric machine according to claim 2 or 4, characterized in that:

the rotating shaft (11), the yoke (12), the holder (13), and the upper cover (14) are integrally formed by insert molding.

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

the magnet (3) is a tile-shaped magnet.

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

the holding frame (13) is positioned among the magnets (3) and used for keeping the position relation among the magnets (3).

8. An electric machine characterized by: the motor includes the rotor structure of stator structure and motor, the motor includes that stator structure and relative stator structure carry out rotatory rotor structure, its characterized in that:

9. The electric machine of claim 8, wherein: the molded body (1) further integrally has an upper cover (14) connected to the yoke (12) and covering the magnet (3) together with the yoke (12).

10. The electric machine according to claim 8 or 9, characterized in that: the rotating shaft (11) and the yoke (12) are metal parts.

11. The electric machine of claim 9, wherein: the holder (13) and the upper cover (14) are plastic parts.

12. The electric machine according to claim 8 or 11, characterized in that: the rotating shaft (11), the yoke (12), the holder (13), and the upper cover (14) are integrally formed by insert molding.

13. The electric machine according to claim 8 or 9, characterized in that: the magnet (3) is a tile-shaped magnet.

14. The electric machine according to claim 8 or 9, characterized in that: the holding frame (13) is positioned among the magnets (3) and used for keeping the position relation among the magnets (3).

15. The electric machine of claim 14, wherein:

the stator structure is connected with a circuit board (4),

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).

16. The electric machine of claim 5, wherein:

a small hole for inserting the pin (24) is formed on the plastic bottom (23) of the iron core (21), one end of the pin (24) passes through the small hole to be connected with the coil (22),

the pad (41) on the circuit 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 connection hole of the pad (41) to be electrically connected with the circuit board (4).