Brushless motor without attracting iron powder

Abstract

The utility model discloses a brushless motor without attracting iron powder, which comprises a motor stator main body, a motor rotor main body is rotatably connected in the motor stator main body, the motor stator main body comprises stator punching sheets, a connection gap is arranged between the motor stator main body and the motor rotor main body, and the stator punching sheets are connected with the motor rotor main body. The motor rotor main body comprises a rotor punching sheet, a magnetic steel sheet is arranged on the rotor punching sheet, an enameled wire is arranged at a stator winding position on the inner side of the motor stator main body, the maximum gap between the motor stator main body and the motor rotor main body is 1.45 mm, and the minimum gap between the motor stator main body and the motor rotor main body is 0.4 mm. According to the brushless motor without attracting iron powder, the stator and rotor structures of the motor are changed, the magnetic field distribution is changed, the motion state of iron dust particles is changed, the iron dust particles cannot be attracted by strong magnets on the rotor, the iron dust particles move smoothly and are not blocked in air gaps of the stator and the rotor, and the motor works normally.

Description

Technical Field

[0001] The utility model relates to the technical field of brushless motors, in particular to a brushless motor that does not absorb iron powder. Background Art

[0002] Brushless motors are energy-driven support devices widely used in various tools and applications, particularly in marine shipbuilding. Traditional series-wound motors, due to their insufficient power and torque, high energy consumption, and low efficiency, are unsuitable for the high-intensity marine shipbuilding applications. Brushless motors offer high power, high torque, high efficiency, and long life, making them suitable for a wide range of applications. These motors are used in high-voltage brushless angle grinders, which are used in the manufacture of marine shipbuilding equipment. Their high power and high torque make them suitable for grinding and cutting high-strength structures in marine equipment. However, the grinding process in shipbuilding generates a large amount of iron dust. The strong magnetic rotor of the motor attracts this dust, which accumulates and blocks the air gap between the stator and rotor, causing overheating and demagnetization, resulting in motor weakness and tool failure. To address this problem in conventional brushless motors, we designed a brushless motor with a structure that resists this attraction. Summary of the Invention

[0003] Technical problem solved: In response to the shortcomings of the existing technology, the utility model provides a brushless motor that does not attract iron powder. It changes the stator and rotor structure of the motor, changes the magnetic field distribution, and changes the movement state of iron dust particles. The strong magnet on the rotor cannot attract iron dust particles. The iron dust particles can move smoothly in the air gap between the stator and rotor without blockage, and the motor works normally, which can effectively solve the problems in the background technology.

[0004] Technical solution: To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a brushless motor that does not absorb iron powder, comprising a motor stator body, the internal rotation of the motor stator body is connected to the motor rotor body, the motor stator body comprises a stator punching, a connection gap is set between the motor stator body and the motor rotor body, the motor rotor body comprises a rotor punching, a magnetic steel sheet is set on the rotor punching, an enameled wire is set at the stator winding position on the inner side of the motor stator body, the maximum gap between the motor stator body and the motor rotor body is 1.45mm, and the minimum gap between the motor stator body and the motor rotor body is 0.4mm.

[0005] As a preferred technical solution of the present application, in the structure composed of the motor stator body and the motor rotor body, the force direction of the iron powder particles in the magnetic field is opposite to the movement direction of the rotor punching.

[0006] As a preferred technical solution of the present application, during the rotation of the fan blades, the direction of the wind entering between the motor stator body and the motor rotor body is the same as the movement direction of the rotor punchings.

[0007] As a preferred technical solution of the present application, the wind drives the iron powder particles to move axially spirally toward the air outlet between the air gap between the motor stator body and the motor rotor body, and the iron powder particles obtain kinetic energy, momentum and driving force under the pressure of the wind.

[0008] As a preferred technical solution of the present application, the iron powder particles are subjected to the thrust of wind pressure during the movement between the air gap of the motor stator body and the motor rotor body, which offsets a part of the force on the iron particles in the magnetic field. At this time, the ferromagnetic attraction of the iron powder particles is weakened, and the iron powder particles are weakened from being adsorbed by the ferromagnetic surface. The iron powder particles flow axially spirally toward the air outlet with the wind and are discharged from the body without sticking to the inner cavity of the motor.

[0009] As a preferred technical solution of the present application, the iron powder particles are subjected to a force in a magnetic field: F1=m.▽B; wherein F1 is the force on the iron powder particles in the magnetic field, m is the magnetic moment vector of the iron powder particles in the magnetic field, "." is the dot product, ▽ is the divergence, and B is the magnetic field induction intensity;

[0010] F2=Pq*S

[0011] Pq=Pi+Pb,Pb=0.5*ρ*υ2

[0012] Among them, F2 is the force of air pushing the iron powder particles forward, S is the surface area of ​​the iron powder particles, Pq is the total pressure of the gas, Pi is the pressure prohibited by the gas, Pb is the pressure generated by the air movement, ρ is the air density, and υ is the air flow velocity.

[0013] As a preferred technical solution of the present application, the motor stator body and the motor rotor body form a brushless motor to perform energy conversion, converting electrical energy into mechanical energy: Pe = TeΩ, where Pe is electromagnetic power, Te is electromagnetic torque, Ω = W1 / P, W1 is the stator current frequency, and P is the logarithm of the magnetic magnitude.

[0014] Beneficial effects: Compared with the prior art, the utility model provides a brushless motor that does not absorb iron powder, which has the following beneficial effects: the brushless motor that does not absorb iron powder changes the stator and rotor structure of the motor, changes the magnetic field distribution, and changes the movement state of iron dust particles. The strong magnet on the rotor cannot absorb iron dust particles, and the iron dust particles can move smoothly in the air gap between the stator and rotor without blockage, and the motor works normally; the brushless motor with this structure is used in the shipbuilding and grinding process. In the environment of strong iron dust, the strong magnet of the motor does not absorb iron powder, the motor generates very little heat, and the motor has the advantages of high power, high torque, high working efficiency, low energy consumption, and low cost. The entire brushless motor has a simple structure, is easy to operate, and has better use effect than other brushless motor methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The utility model is a schematic diagram of the overall structure of a brushless motor that does not absorb iron powder.

[0016] Figure 2 The utility model is a schematic diagram of the structure of the connection between the stator punching and the rotor punching in a brushless motor that does not absorb iron powder.

[0017] Figure 3 This is a schematic structural diagram of the overall side of a brushless motor that does not absorb iron powder in the present invention.

[0018] Figure 4 This is the control principle diagram of brushless DC motor.

[0019] Figure 5 This is the AC brushless motor control schematic.

[0020] Figure 6 This is the voltage phasor diagram of the brushless permanent magnet motor.

[0021] Figure 7 This is a force diagram of iron powder particles (iron powder with small magnetic moment) in a brushless motor that does not absorb iron powder according to the utility model.

[0022] In the figure: 1. Motor stator body; 2. Motor rotor body; 101. Stator punching sheet; 102. Connection gap; 103. Enameled wire; 201. Rotor punching sheet; 202. Magnetic steel sheet. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0024] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating positions or relationships, are based on the positions or relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0026] like Figure 1-7 As shown, a brushless motor that does not absorb iron powder includes a motor stator body 1, the internal rotation of the motor stator body 1 is connected to the motor rotor body 2, the motor stator body 1 includes a stator punching 101, a connection gap 102 is set between the motor stator body 1 and the motor rotor body 2, the motor rotor body 2 includes a rotor punching 201, a magnetic steel sheet 202 is set on the rotor punching 201, an enameled wire 103 is set at the stator winding position on the inner side of the motor stator body 1, the maximum gap between the motor stator body 1 and the motor rotor body 2 is 1.45 mm, and the minimum gap between the motor stator body 1 and the motor rotor body 2 is 0.4 mm. By changing the motor stator and rotor structure, changing the magnetic field distribution, and changing the movement state of the iron dust particles, the strong magnet on the rotor cannot attract the iron dust particles, and the iron dust particles move smoothly in the stator and rotor air gap without blockage, and the motor works normally.

[0027] Furthermore, in the structure composed of the motor stator body 1 and the motor rotor body 2 , the force direction of the iron powder particles in the magnetic field is opposite to the movement direction of the rotor punching 201 .

[0028] Furthermore, during the rotation of the fan blades, the direction of the wind entering between the motor stator body 1 and the motor rotor body 2 is the same as the movement direction of the rotor punching 201 .

[0029] Furthermore, the wind drives the iron powder particles to move axially and spirally toward the air outlet between the air gap between the motor stator body 1 and the motor rotor body 2, and the iron powder particles obtain kinetic energy, momentum and driving force under the pressure of the wind.

[0030] Furthermore, the iron powder particles are subjected to the thrust of wind pressure during the movement between the air gap of the motor stator body 1 and the motor rotor body 2, which offsets part of the force on the iron particles in the magnetic field. At this time, the ferromagnetic attraction of the iron powder particles is weakened, and the iron powder particles are weakened from being adsorbed by the ferromagnetic surface. The iron powder particles flow axially spirally toward the air outlet with the wind and are discharged from the body without sticking to the inner cavity of the motor.

[0031] Furthermore, the force exerted on the iron powder particles in the magnetic field is: F1 = m.▽B; where F1 is the force exerted on the iron powder particles in the magnetic field, m is the magnetic moment vector of the iron powder particles in the magnetic field, “.” is the dot product, ▽ is the divergence, and B is the magnetic field induction intensity;

[0032] F2=Pq*S

[0033] Pq=Pi+Pb,Pb=0.5*ρ*υ2

[0034] Among them, F2 is the force of air pushing the iron powder particles forward, S is the surface area of ​​the iron powder particles, Pq is the total pressure of the gas, Pi is the pressure prohibited by the gas, Pb is the pressure generated by the air movement, ρ is the air density, and υ is the air flow velocity.

[0035] Furthermore, the motor stator body 1 and the motor rotor body 2 form a brushless motor to perform energy conversion, converting electrical energy into mechanical energy: Pe = TeΩ, where Pe is electromagnetic power, Te is electromagnetic torque, Ω = W1 / P, W1 is the stator current frequency, and P is the logarithm of the magnetic magnitude.

[0036] 1: The principle of brushless motor movement:

[0037] The energy conversion of the brushless motor is also from electrical energy to mechanical energy: Pe = TeΩ (P E is the electromagnetic power, Te is the electromagnetic torque, Ω=W1 / P, W1 is the stator current frequency, P is the logarithm of the magnetic level)

[0038] Power generation in brushless AC / DC motors occurs through a control circuit that sequentially switches on the inverter power transistors to power the motor's stator coils. Electromagnetic torque is generated by current flowing through the stator coils, cutting through the rotor's magnetic field and generating an induced electromotive force. The magnetic field forces the current-carrying conductor, generating electromagnetic torque. This electromagnetic torque then generates rotor motion, converting electrical energy into magnetic energy and magnetic energy into mechanical energy.

[0039] Brushless motor voltage equation:

[0040]

[0041] E0 is the main magnetic flux Q0 generated by the permanent magnet and the exciting electromotive force generated in the stator winding R a is the stator resistance per phase, and are the direct-axis and quadrature-axis components of the stator current, respectively, X d and X q is the virtual electromotive force of the direct-axis and quadrature-axis reactance: Electromagnetic power: Electromagnetic torque: X d =W1Ld;X q =W1L q ,

[0042] 2. Pain points encountered in brushless motor movement

[0043] Pain points encountered in brushless motor movement: Brushless motors are prone to heating up in dusty (iron dust) environments. The movement principle of brushless motors has been explained above: the power supply is turned on by the control circuit in an algorithmic sequence to turn on the inverter power tube and supply power to the stator coil of the motor. The conductor with current generates electromagnetic torque under the action of the magnetic field force, and the rotor generates rotor movement under the action of the electromagnetic torque. Advantages of brushless motors in scene applications: Motors of the same weight have high power and strong torque, which can meet the needs of high power and high torque in scenes. However, some products (such as angle grinders) will heat up during use due to blockage or accumulation of iron powder, and in severe cases, there is a possibility of burning the machine.

[0044] In order to solve the pain points of the product, the utility model: changes the structure of the stator and rotor, changes the distribution of the magnetic field in the air gap between the stator and rotor, thereby changing the movement state of the particles in the magnetic field, reducing the force applied to the particles during movement, making it difficult for the particles to be adsorbed by the rotor and carried out by the wind, and making it difficult for the stator and rotor of the machine to be blocked, and there is no heat or burning phenomenon.

[0045] 3: The state of iron powder particles in the magnetic field

[0046] Iron powder particles are attracted to a magnet because the magnetic field generated by the magnet interacts with the electrons in the iron powder. A magnet is an object with a magnetic field that attracts ferromagnetic materials such as iron and cobalt. The magnet's attraction to iron is based on the magnetic field, which is generated by the movement of electrons within the magnet. This movement of electrons generates a magnetic field, which in turn acts on surrounding objects, attracting ferromagnetic materials to the magnet's surface. The electrons in the iron powder have spin and orbital angular momentum, which interact to form a magnetic moment. Because the spin and orbital angular momentum of the electrons in the iron powder are regular, their interaction creates a relatively large magnetic moment. When the magnet's magnetic field acts on this magnetic moment, the electrons in the iron powder are deflected, causing the iron powder to be attracted. When a large number of iron powder particles are attracted, the magnet heats up and its magnetic properties decrease. Iron powder particles are not attracted in a uniform magnetic field. However, in real-world applications, the magnetic field is non-uniform. Iron powder particles are attracted to the magnet's surface in a non-uniform magnetic field. In actual applications, the air gap between the stator and rotor of the motor is uneven. Due to the different distribution densities of the air gap magnetic field, the iron particles are magnetized into small magnetic moments under the magnetic field. These small magnetic moments have different potential energies in the uneven magnetic field, causing the small magnetic moments to be acted upon by a force in the magnetic field. The direction of this force is from the smaller magnetic induction intensity to the larger magnetic induction intensity, causing them to be attracted by the magnet.

[0047] 4. Change the force state of iron powder particles in the magnetic field

[0048] Change the structure of the motor's stator and rotor so that the direction of force on the iron powder particles in the magnetic field is opposite to the direction of movement of the rotor. When the fan blades rotate, the direction of the wind entering between the stator and rotor is the same as the direction of movement of the rotor. The wind drives the iron powder particles to move in an axial spiral between the stator and rotor air gap toward the air outlet. Driven by the pressure of the wind, the iron powder particles gain kinetic energy, momentum, and driving force. During the movement between the stator and rotor air gaps, the iron powder particles are subjected to the thrust of wind pressure, which offsets part of the force on the iron particles in the magnetic field, weakening the ferromagnetic attraction of the iron powder particles and weakening the adsorption of the iron powder particles by the ferromagnetic surface. The iron powder flows in an axial spiral toward the air outlet with the wind and is discharged from the body without sticking to the inner cavity of the motor. The analysis is as follows:

[0049] The force exerted on iron powder particles in a magnetic field is: F1=m.▽BF1 is the force exerted on iron powder particles in a magnetic field, m is the magnetic moment vector of the iron powder particles in the magnetic field, “.” is the dot product, ▽ is the divergence, and B is the magnetic field induction intensity.

[0050] F2 = Pq * SPq = Pi + Pb, where Pb = 0.5 * ρ * υ2. F2 is the force exerted by the air on the iron powder particles, S is the surface area of ​​the iron powder particles, Pq is the total pressure of the gas, Pi is the pressure of the gas, Pb is the pressure exerted by the air, ρ is the air density, and υ is the air velocity.

[0051] Operating Principle: Utilizes a synchronous (DC) brushless permanent magnet motor, operated by an electronically controlled inverter. Brushless motor electronic control systems have a wide range of applications. This motor is used in high-voltage brushless angle grinders, particularly in the manufacture of marine equipment. Its high power and torque make it suitable for grinding and cutting high-strength structures in marine equipment.

[0052] However, the high-voltage brushless angle grinder of this motor produces a large amount of iron dust during the grinding process in shipbuilding. The strong magnetic motor rotor will strongly absorb the iron powder, which will accumulate and block the air gap between the stator and rotor, causing heat and demagnetization, making the motor weak and the tool unusable.

[0053] Changing the stator and rotor structure of the motor changes the magnetic field distribution and the movement state of the iron dust particles. The strong magnet on the rotor cannot attract the iron dust particles. The iron dust particles can move smoothly in the air gap between the stator and rotor without blockage, and the motor works normally.

[0054] It should be noted that, in this article, relational terms such as first and second (number one, number two), etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including a..." do not exclude the presence of other identical elements in the process, method, article or device that includes the elements.

[0055] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements shall fall within the scope of the present invention as claimed.

Claims

1. A brushless motor that does not absorb iron powder, comprising a motor stator body (1), characterized in that: The motor stator body (1) is rotatably connected to the motor rotor body (2) inside. The motor stator body (1) includes a stator punching sheet (101). A connection gap (102) is provided between the motor stator body (1) and the motor rotor body (2). The motor rotor body (2) includes a rotor punching sheet (201). A magnetic steel sheet (202) is provided on the rotor punching sheet (201). An enameled wire (103) is provided at the stator winding position inside the motor stator body (1). The maximum gap between the motor stator body (1) and the motor rotor body (2) is 1.45 mm, and the minimum gap between the motor stator body (1) and the motor rotor body (2) is 0.4 mm.

2. The brushless motor without iron powder absorption according to claim 1, characterized in that: In the structure composed of the motor stator body (1) and the motor rotor body (2), the force direction of the iron powder particles in the magnetic field is opposite to the movement direction of the rotor punching (201).

3. The brushless motor without iron powder absorption according to claim 1, characterized in that: During the rotation of the fan blades, the direction of the wind entering between the motor stator body (1) and the motor rotor body (2) is the same as the movement direction of the rotor punching (201).

4. The brushless motor without iron powder absorption according to claim 1, characterized in that: The wind drives the iron powder particles to move in an axial spiral manner toward the air outlet between the air gap of the motor stator body (1) and the motor rotor body (2), and the iron powder particles obtain kinetic energy, momentum and driving force under the pressure of the wind.

5. The brushless motor without iron powder absorption according to claim 4, characterized in that: The iron powder particles are subjected to the thrust of wind pressure during movement between the air gap of the motor stator body (1) and the motor rotor body (2), which offsets a portion of the force exerted on the iron particles in the magnetic field. At this time, the ferromagnetic attraction of the iron powder particles is weakened, and the iron powder particles are weakened from being adsorbed by the ferromagnetic surface. The iron powder particles flow in an axial spiral toward the air outlet along with the wind and are discharged from the machine body without sticking to the inner cavity of the motor.

6. The brushless motor without iron powder absorption according to claim 5, characterized in that: The iron powder particles are subjected to a force in a magnetic field: F1 = m.▽B; where F1 is the force on the iron powder particles in the magnetic field, m is the magnetic moment vector of the iron powder particles in the magnetic field, "." is the dot product, ▽ is the divergence, and B is the magnetic field induction intensity; F2=Pq*S Pq=Pi+Pb,Pb=0.5*ρ*υ2 Among them, F2 is the force of air pushing the iron powder particles forward, S is the surface area of ​​the iron powder particles, Pq is the total pressure of the gas, Pi is the pressure prohibited by the gas, Pb is the pressure generated by the air movement, ρ is the air density, and υ is the air flow velocity.

7. The brushless motor without iron powder absorption according to claim 1, characterized in that: The motor stator body (1) and the motor rotor body (2) form a brushless motor to perform energy conversion, converting electrical energy into mechanical energy: Pe=TeΩ, where Pe is electromagnetic power, Te is electromagnetic torque, Ω=W1 / P, W1 is the stator current frequency, and P is the magnetic level logarithm.

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