TWI587609B - Brushless DC motor - Google Patents

Description

Brushless DC motor

The present invention relates to a direct current motor which is intended to provide an effect of reducing the occurrence of cogging torque while reducing noise, and also relatively saving power during full-time operation of the brushless DC motor.

According to the motor, the motor (also known as the motor) can convert electrical energy into mechanical energy, which drives the machine for rotation, vibration or linear motion. It is widely used in the field of automatic control and electromechanical integration. There are many home appliances in life. All need to use the motor to carry out related operations, and the types and working applications of the relative motors are becoming more and more diverse.

Although there are many types of motors, they can be roughly divided into DC motors and AC motors according to the driving current, and for the basic structure, they are mainly composed of a stator and a rotor. Among them, the AC motor has a simple structure. The price is low, but in the early days, because the shift control was difficult, it was mainly used in fixed speed or multi-speed shift applications.

Since the AC motor is in actual operation, its speed is proportional to the input current frequency. In principle, the higher the frequency, the faster the speed. As the inverter is applied to the AC motor, the shift control has been in the industry for quite some time. In recent years, the rapid development of large-scale integrated circuits, advances in power electronic components, and complex control laws have been realized by microprocessor-based software, enabling variable speed control of AC motors to be achieved by digital inverter drive systems. And then widely used in various fields.

Generally, the rotor of a DC motor is an electromagnet (wrapped with an enameled wire), the stator is a permanent magnet, and the permanent magnet is used as a surrounding magnetic field. The electromagnet wound by the coil is an intermediate rotor, mainly by changing the current direction in a timely manner. The rotor can continue to rotate in the same direction; for example, a brushed DC motor is driven by a current flowing through a brush and then rotated by an armature, and the vertical magnetic field is generated by adding a plurality of sets of wire-wound windings on the rotor, via a brush ( Brush) and commutation adjustment, so that the current flowing into the armature can control the rotor magnetic field to remain in the direction perpendicular to the magnetic field.

As for the brushless DC motor, it mainly solves the problem of brush and phase changer maintenance of the brushed DC motor. The biggest difference between the operation principle and the brushed DC motor is that the brushless DC motor is replaced by an electronic phase change. The purpose of maintaining the rotor and stator magnetic fields at a predetermined phase difference is achieved.

However, when the conventional brushless DC motor is used for speed adjustment, it can be achieved by changing the electric voltage. It will feel simpler and easier under the condition, but if the motor is loaded, it will seriously cause the problem of insufficient torque. The power supply of a larger power must be selected to start the motor from a standstill, which not only causes the power supply to be limited by the brushless DC motor, but also consumes relatively much power during the full-time operation of the brushless DC motor.

In view of the above, the present invention provides an effect of reducing the occurrence of cogging torque and reducing noise, and also relatively saving power during the full-time operation of the brushless DC motor.

In order to achieve the above, the brushless DC motor of the present invention basically comprises: at least two stators, and a rotor; wherein: the two stator systems are arranged along a same axis, each stator has a The annular body is provided with stator teeth extending toward the center of the body, and a shoe portion is formed at the end of each stator tooth, and a predetermined number of gates is arranged on each stator tooth. a coil, and the shoe portions of the two stators are alternately arranged in a circular hole shape; the rotor is disposed in a circular hole-like configuration of the two stators, and the rotor is disposed on a rotating shaft and is provided with a plurality of Permanent magnets, and all permanent magnets are arranged in such a way that the outer periphery of the shaft forms a south/north interlaced configuration.

With the above technical features, the brushless DC motor of the present invention can be electrically connected to a DC power source through an inverter circuit, and is integrated with a microcontroller and a gate drive circuit. According to the received speed control signal and the signal transmitted by the Hall sensing element, the coil circuit of the two stators is driven alternately, or the coil circuit of any stator is driven to form an interaction between the energized stator and the rotor. The electromagnetic field causes the rotor to continue to rotate in the same direction. Not only can the power supply of the brushless DC motor be reduced, but also the power is saved during the full-time operation of the brushless DC motor, thereby reducing the cogging torque and reducing the noise.

According to the above technical feature, the brushless DC motor is further provided with at least one Hall sensing element at the periphery of the two stators.

According to the above technical feature, the stator is further electrically connected to a power source by an inverter circuit, and the inverter circuit is connected in series.

According to the above technical feature, the gap of the boot preferably ranges from 2 mm to 5 mm.

According to the above technical feature, the stator teeth are electrical angles of the spacing (180 degrees/m) of the adjacent coils, and m is the number of stators.

Each of the stators is provided with eight stator teeth, and the rotor is provided with eight permanent magnets.

According to the above technical feature, each of the stator systems is provided with an even number of stator teeth, and the rotor is provided with an even number of permanent magnets.

According to the above technical features, each of the stator systems is respectively provided with an even number of stator teeth, The rotor is provided with an even number of permanent magnets corresponding to the stator.

Each of the stators is composed of a plurality of silicon steel sheets of the same configuration.

The axial length of each of the permanent magnets covers the range of shoe settings of the two stators.

The present invention further provides a brushless DC motor, comprising: at least two stators arranged along an identical axis, each stator has an annular body, and each stator is composed of a plurality of silicon steel sheets of the same configuration. a stacking body is disposed on the body with stator teeth extending toward the center of the body, a boot portion is formed at a tail end of each stator tooth, and a coil of a predetermined number of turns is disposed on each stator tooth, and the adjacent shoe portion is disposed The gap is in the range of 2 mm to 5 mm, and the two stators are staggered around each other in a circular hole configuration, and at least one Hall sensing element is disposed at the periphery of the two stators. The adjacent coils of the stator teeth are electrical angles spaced apart from each other (180 degrees/m), and m is the number of stators; a rotor is disposed in a circular hole-like configuration of the two stators, and the rotor is coupled to the rotor A plurality of permanent magnets are disposed around the rotating shaft, and all of the permanent magnets are arranged in a manner of forming a south/North pole staggered configuration on the periphery of the rotating shaft. The stator system is respectively provided with an even number of stator teeth, and the rotor is provided with an even number of permanent magnets. , each permanent magnet It covers the range of the shoe portion disposed in the longitudinal lines of the two stator.

Specifically, the brushless DC motor disclosed in the present invention mainly generates a high torque output during low-speed operation and a mode of driving a coil circuit of any stator by driving the coil circuits of two stators alternately. Producing a cogging torque and reducing the effect of noise can not only reduce the limitation of the power supply of the brushless DC motor, but also save energy during the full-time operation of the brushless DC motor.

11‧‧‧Inverter circuit

12‧‧‧Microcontroller

13‧‧‧ gate drive circuit

20‧‧‧Brushless DC Motor

21‧‧‧ Stator

211‧‧‧ body

212‧‧‧Standard teeth

213‧‧‧ Boots

214‧‧‧ coil

22‧‧‧Rotor

221‧‧‧ shaft

222‧‧‧ permanent magnet

23‧‧‧ Hall Inductive Components

Fig. 1 is a perspective view showing the appearance of a brushless DC motor of the present invention.

Fig. 2 is an exploded view showing the structure of the brushless DC motor of the present invention.

Figure 3 is a cross-sectional view showing the structure of the brushless DC motor of the present invention.

Fig. 4 is a reference diagram of the configuration of the brushless DC motor of the present invention.

Fig. 5 is a schematic view showing the magnetic interaction relationship between the stator and the rotor when the brushless DC motor of the present invention operates in a manner of mutually driving the coil circuits of the two stators.

Fig. 6 is a schematic view showing the magnetic interaction relationship between the stator and the rotor when the brushless DC motor of the present invention operates in the manner of driving the coil circuit of any of the stators.

The present invention mainly provides a brushless DC motor which can generate a high torque output during low speed operation and a low torque output during high speed operation. For example, FIG. 1 is a perspective view of the brushless DC motor of the present invention, and FIG. 2 The brushless DC motor structure of the present invention is shown in a sectional view of the brushless DC motor of the present invention. The brushless DC motor 20 of the present invention basically comprises: two stators 21, and a rotor 22; The two stators 21 are arranged along a same axis. Each of the stators 21 has an annular body 211. The body 211 is provided with stator teeth 212 extending toward the center of the body 211. A tail portion 213 is formed on the end of the stator tooth 212, and a coil 214 having a predetermined number of turns is disposed on each of the stator teeth 213. The gap of the shoe portion 213 is preferably between 2 mm and 5 mm. Less than 2 mm is difficult to wind, and more than 5 mm is easy to generate useless magnetic force, and the cost is higher, and the boots 213 of the two stators 21 are interlaced around each other in a circular hole configuration; in implementation, the stator systems are Multiple Syndiotactic configuration stacking silicon steel configuration.

The adjacent teeth 214 of the stator teeth 212 are electrical angles spaced apart from each other (180 degrees/m), and m is the number of the stators 21, where the relationship between the mechanical angles and the electrical angles is unambiguously The number of stators is determined. Further, the adjacent coils of the stator teeth are electrical angles spaced apart from each other (180 degrees/m), and m is the number of stators.

Therefore, one cycle of the electrical angle does not correspond to one cycle of the mechanical angle. In the preferred embodiment of the present invention, two stators 21, the stator teeth 212 of the stators 21 are eight, and one cycle of the electrical angle It corresponds to 1/4 of the rotation angle of the rotor 22. At this time, even if the electrical angle is an induced voltage at a constant angle, the induced voltage is detected at a position different from the mechanical angle. If the mechanical angles are different, there may be a case where a change is made in the induced voltage based on the mechanical structure of the number of the stators 21.

The rotor 22 is disposed in a circular hole-like configuration of the two stators 21. The rotor 22 is disposed on a rotating shaft 221 and is provided with a plurality of permanent magnets 222, and all of the permanent magnets 222 are formed on the periphery of the rotating shaft. The arrangement of the north pole staggered configuration is arranged; and the brushless DC motor 20 of the present invention is further provided with at least one Hall sensing for sensing the position of the permanent magnet 222 at the periphery of the two stators 21 Element 23.

Furthermore, the present invention treats the stators as independent phases. Compared with the conventional motor stator, the UVW three-phase transmission coils are wound around the stator teeth of the same stator, and the UVW phase each accounts for 1/3. That is, the U phase occupies an angle of 120 degrees. However, in the present invention, the two stators are respectively classified into a UV phase, and the three stators are in a UVW phase, and any one of the stators functions only as a U, V or W phase, that is, 360 degrees are all U phase.

Referring to FIG. 4, the brushless DC motor 20 of the present invention can be electrically connected to a DC power source through an inverter circuit 11 in use, wherein the inverter circuit 11 is adopted. Connected in series, and in conjunction with a microcontroller 12 and a gate drive circuit 13, in accordance with the received speed control signal and the signal transmitted by the Hall sensing element 23, to interactively drive the two stators 21 The coil circuit (as shown in Fig. 5), or the coil circuit of any of the stators 21 (as shown in Fig. 6), causes the energized stator 21 and the rotor 22 to form an electromagnetic field that causes the rotor 22 to continue. Rotate in the same direction.

That is, the brushless DC motor disclosed in the present invention can be started from a stationary state without requiring a high-power power source, and can be further switched to operate in a manner of driving a coil circuit of any of the stators after being operated to a set rotational speed. Not only can the power supply of the brushless DC motor be reduced, but also the power is saved during the full-time operation of the brushless DC motor.

In this embodiment, each of the stators 21 is provided with eight stator teeth 212; the rotor 22 is provided with eight permanent magnets 222; further, the axial length of each of the permanent magnets 222 covers the The shoe portions 213 of the two stators 21 are preferably set in a range.

It is worth mentioning that, in the specific implementation of the brushless DC motor of the present invention, the number of stator teeth of each stator and the number of permanent magnets of the rotor can be designed according to actual size and have different number of configurations, and appropriate The driving circuit can effectively improve the operating efficiency of the overall brushless DC motor or increase the range of the rotating speed by effectively controlling the coil commutation timing of each stator.

Compared with the conventional conventional technology, the brushless DC motor disclosed in the present invention mainly reduces the occurrence of cogging torque, reduces the noise effect, and operates on the motor by mutually driving the coil circuits of the two stators. After the set speed, it can be switched to drive the coil circuit of any stator, which not only reduces the limitation of the power supply of the brushless DC motor, but also saves energy during the full-time operation of the brushless DC motor. .

In summary, the present invention provides a preferred and feasible brushless DC motor, and the invention patent application is provided according to the law; the technical content and technical features of the present invention have been disclosed above, but those skilled in the art may still be based on the present invention. The invention is to be construed as being limited and modified by the spirit of the invention. Therefore, the scope of the present invention should be construed as being limited by the scope of the appended claims

20‧‧‧Brushless DC Motor

21‧‧‧ Stator

211‧‧‧ body

212‧‧‧Standard teeth

213‧‧‧ Boots

214‧‧‧ coil

22‧‧‧Rotor

221‧‧‧ shaft

222‧‧‧ permanent magnet

23‧‧‧ Hall Inductive Components

Claims (10)

A brushless DC motor comprising: at least two stators arranged along an identical axis, each stator has an annular body, and the body is provided with stator teeth extending toward the center of the body. a tail portion is formed at each end of the stator teeth, and a coil of a predetermined number of turns is wound around each of the stator teeth, and the boots of the two stators are alternately arranged in a circular hole shape; further, the stator is further An inverter circuit is electrically connected to a power source, and the inverter circuit is connected in series; a rotor is disposed in a circular hole configuration of the two stators, and the rotor is disposed on a rotating shaft and is provided with a plurality of Permanent magnets, and all permanent magnets are arranged in such a way that the outer periphery of the shaft forms a south/north interlaced configuration. The brushless DC motor of claim 1, wherein the brushless DC motor further comprises at least one Hall sensing element at a periphery of the two stators. The brushless DC motor of claim 1, wherein the gap of the adjacent shoe ranges from 2 mm to 5 mm. A brushless DC motor according to any one of claims 1 to 3, wherein the stator teeth are electrical angles of the spacing (180 degrees/m) of adjacent coils, and m is the number of stators. A brushless DC motor according to any one of claims 1 to 3, wherein each of the stators is provided with eight stator teeth, respectively, and the rotor is provided with eight permanent magnets. A brushless DC motor according to any one of claims 1 to 3, wherein each of the stators is provided with an even number of stator teeth, the rotor being provided with an even number of permanent magnets. A brushless DC motor according to any one of claims 1 to 3, wherein each of the stators is provided with an even number of stator teeth each having an even number of permanent magnets corresponding to the stator. A brushless DC motor according to any one of claims 1 to 3, wherein each of the stator systems is formed by stacking a plurality of silicon steel sheets of the same configuration. A brushless DC motor according to any one of claims 1 to 3, wherein the axial length of each of the permanent magnets covers a range of shoe settings of the two stators. A brushless DC motor comprising: at least two stators arranged along an identical axis, each stator has an annular body, and each stator is composed of a plurality of silicon steel sheets of the same configuration, A stator tooth extending toward a center of the body is disposed on the body, and a boot portion is formed at a tail end of each stator tooth, and a coil of a predetermined number of turns is disposed on each stator tooth, and a gap of the adjacent boot portion is in a range The system is between 2mm and 5mm, and the two stators are staggered around each other in a circular hole shape, and at least one Hall sensing element is disposed at the periphery of the two stators. The adjacent coils of the teeth are electrical angles spaced apart from each other (180 degrees/m), and m is the number of stators. Further, the stator is further electrically connected to a power source by an inverter circuit, and the inverter circuit is connected in series. a rotor, which is disposed in a circular hole-like configuration of the two stators, the rotor is disposed on a rotating shaft and is provided with a plurality of permanent magnets, and all of the permanent magnets are formed in a south/north interlaced configuration on the periphery of the rotating shaft. Mode arrangement, this Subsystem are provided an even number of stator teeth, the rotor has an even number of permanent magnets based, the axial length of the permanent magnet system of the shoe cover portion setting range of the two stators.