Motor rotor, motor and range hood

Abstract

The utility model discloses a motor rotor, a motor and a range hood. The motor rotor is characterized in that combined magnetic steel is formed by combining at least two kinds of magnetic steel; the rotating shaft is arranged in a hollow inner cavity of the rotor body formed by the combined magnetic steel; the filler assembly is used for filling a gap between the combined magnetic steel and the rotating shaft; an included angle beta is formed between the magnetization direction of each piece of magnetic steel in the combined magnetic steel and the horizontal line where the width direction of the magnetic steel is located, and beta is larger than 0 degree and smaller than 90 degrees. Compared with the prior art, the combined magnetic steel has the advantages that the magnetic steel sheets in the combined magnetic steel adopt different magnetization directions, so that the combined magnetic steel designed by the scheme has a magnetic field waveform with better sinusoidal property, and due to the guide effect of the magnetization directions, a motor adopting the magnetized magnetic steel has smaller magnetic density of a rotor yoke part, thereby being beneficial to reducing the height of the rotor yoke and improving the reliability of the motor. The motor has better electromagnetic performance, a larger magnetic field amplitude can be obtained under the condition of the same magnetic steel consumption, and larger magnetic flux can be obtained.

Description

Technical Field

[0001] The utility model relates to a motor device, in particular to a motor rotor, a motor using the rotor and a range hood operated by the motor. Background Art

[0002] In recent years, range hood products have higher requirements on motor performance and vibration noise, and are clearly developing in the direction of high air pressure, large air volume and low noise. As one of the core components of range hoods, the performance of the motor directly affects the function of the range hood product.

[0003] High power density motors are the key to achieving the above-mentioned range hood performance requirements. At present, range hood products have high requirements for vibration and noise. The vibration and noise factors of the electric motor are mainly concentrated in the rotor. The structural strength of the rotor and the contact method between the shaft and the impeller are key research objects. The characteristics of the rotor design and process will directly affect the sound quality of the whole machine.

[0004] In the prior art, for example, the existing Chinese utility model patent No. 201821213504.1 "A Surface-mounted Permanent Magnet Rotor Structure" discloses a surface-mounted permanent magnet rotor structure, the excitation magnetic field of which is provided by permanent magnets, the rotor does not require excitation current, and the motor efficiency is improved; although the surface-mounted motor rotor can achieve high power, the pasting is unreliable and the motor speed is limited; for example, the Chinese invention patent No. 201210316633.4 "An Embedded Sinusoidal Permanent Magnet Motor Rotor" discloses an embedded sinusoidal permanent magnet motor rotor, which solves the problem in the prior art that the permanent magnets of traditional motors are generally attached to the outside of the rotor and are easy to fall off when the rotor rotates at high speed. Although the embedded motor rotor can achieve high speed, it has poor load capacity and a high risk of abnormal noise;

[0005] In summary, traditional electric motors have problems such as large vibration, high noise, low efficiency and high cost during use. Combined with the existing various motor rotor structures, in order to achieve low rotor noise and reduced torque operation, it is necessary to integrate the advantages of the above-mentioned types of rotors into one. However, the manufacturing process is relatively cumbersome and unreliable, and the strength of the integrity cannot be guaranteed.

[0006] Therefore, how to optimize the traditional rotor structure to improve the performance of the rotor is an urgent problem to be solved, and further improvement and perfection of the existing motor rotor structure is needed. Utility Model Content

[0007] The first technical problem to be solved by the utility model is to provide a motor rotor with higher overall strength and reliability in response to the above-mentioned existing technical status. The rotor structure can effectively improve the vibration of the motor and then reduce the risk of abnormal noise generated by the motor.

[0008] The second technical problem to be solved by the present invention is to provide an electric motor using the above rotor structure in view of the above-mentioned existing technical status, and the electric motor has small vibration and low noise.

[0009] The third technical problem to be solved by the present invention is to provide a range hood which adopts the above-mentioned motor to work in view of the above-mentioned existing technical status.

[0010] The technical solution adopted by the utility model to solve the above-mentioned first technical problem is: a motor rotor, characterized in that the motor rotor includes:

[0011] Combined magnetic steel, a rotor body with a hollow inner cavity formed by combining at least two magnetic steels;

[0012] The rotating shaft is arranged in the hollow inner cavity of the rotor body composed of the combined magnetic steel;

[0013] A filler component, used to fill the gap between the combined magnetic steel and the rotating shaft;

[0014] The magnetization direction of each magnetic steel in the combined magnetic steel is an angle β formed between the radial center line of the magnetic steel and the tangent line of the circle where the magnetic steel is located, and the value range of the angle β is 0°<β<90°.

[0015] Preferably, the combined magnetic steel comprises first magnetic steel and second magnetic steel arranged alternately at intervals, wherein each pair of first magnetic steel and second magnetic steel constitutes a magnetic pole, and the magnetic poles are arranged circumferentially in the order of alternating N poles and S poles, and the magnetization directions between two adjacent groups of magnetic poles are opposite.

[0016] In order to optimize the cogging torque and the pulsating torque and to improve the average torque to a certain extent, preferably, the first magnetic steel is a magnetic steel with a trapezoidal cross-section, and the long side of the trapezoidal cross-section of the first magnetic steel is arranged inwardly close to the rotating shaft, and the short side of the trapezoidal cross-section of the first magnetic steel is arranged outwardly away from the rotating shaft.

[0017] Preferably, the second magnetic steel is a magnetic steel with a fan-shaped cross section, the inner arc of the fan-shaped cross section of the second magnetic steel is arranged inwardly close to the rotating shaft, and the outer arc of the fan-shaped cross section of the second magnetic steel is arranged outwardly away from the rotating shaft. The outer arc and the inner arc of the second magnetic steel are designed as an eccentric structure, so that the motor can obtain a back electromotive force with high sinusoidality and low harmonic content in the air gap magnetic field.

[0018] As a further preferred embodiment, the second magnetic steel is further formed with grooves on both sides of the outer arc of the fan ring section to improve the air gap magnetic field and electromotive force waveform. The groove structure can improve the air gap magnetic field and electromotive force waveform on the one hand, and on the other hand, when filling, the filler can form a wrapping angle to wrap the second magnetic steel, thereby improving the connection strength between the filler and the magnetic steel.

[0019] Preferably, the filler is an integral injection molded part or a plastic-filled part. The filler can fill any air gap, firmly wrap the rotor assembly into a whole, and the processing technology is simple and reliable, and the stability is strong.

[0020] Preferably, the surface of the rotating shaft is provided with a plurality of convex strips which are staggered in the axial direction and spaced apart in the circumferential direction. The convex strips on the rotating shaft surface are designed so that when the filler is filled, a groove can be formed in the central circumferential direction to match the plurality of staggered convex strips on the rotating shaft, thereby enhancing the axial and tangential strength between the filler and the rotating shaft.

[0021] In order to facilitate processing and manufacturing and improve the processing and assembly efficiency of the rotor assembly, preferably, the motor rotor processing mold includes:

[0022] A magnetizing module, magnetizing the magnetic steel according to a magnetizing direction;

[0023] A positioning module is used to position each magnetic steel, arrange the magnetic steel into the combined magnetic steel in a circumferential direction, and fix the rotating shaft in the mold cavity;

[0024] The filling module is used to inject or glue the filler into the mold cavity, and the motor rotor is formed after curing.

[0025] The technical solution adopted by the utility model to solve the second technical problem is: an electric motor, including a rotor and a stator, characterized in that: the rotor adopts the electric motor rotor as described above.

[0026] The technical solution adopted by the utility model to solve the third technical problem is: a range hood, including a housing, a fan and a motor driving the fan to rotate, characterized in that the motor adopts the motor described above.

[0027] Compared with the prior art, the advantages of the utility model are: a rotor-free core structure is adopted, and the combined magnetic steel and the rotating shaft are integrally formed by a filler, which not only simplifies the processing steps, but also helps to reduce the moment of inertia and the weight of the motor, improve the torque density and power density of the motor, increase the speed range of the motor, and reduce the cost of the motor; secondly, the magnetic steel sheets in the combined magnetic steel adopt different magnetization directions, so that the combined magnetic steel designed in this scheme has a more sinusoidal magnetic field waveform, and due to the guiding effect of the magnetization direction, the motor using this magnetized magnetic steel has a smaller rotor yoke magnetic density, which is beneficial to reducing the rotor yoke height, and the motor has better electromagnetic properties. When the same amount of magnetic steel is used, a larger magnetic field amplitude can be obtained, and a larger magnetic flux can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the three-dimensional structure of the combined magnetic steel of the motor rotor according to an embodiment of the utility model.

[0029] Figure 2 Schematic diagram of the magnetization direction of the combined magnetic steel of the motor rotor according to an embodiment of the utility model.

[0030] Figure 3a This is a schematic diagram of the structure of the first magnetic steel in the combined magnetic steel of an embodiment of the utility model.

[0031] Figure 3b for Figure 3a A projection view of the first magnetic steel is shown.

[0032] Figure 4a Schematic diagram of the second magnetic steel structure in the combined magnetic steel of an embodiment of the utility model.

[0033] Figure 4b for Figure 4a A projection view of the second magnetic steel is shown.

[0034] Figure 5 It is a schematic diagram of the three-dimensional structure of the filler of the motor rotor according to an embodiment of the utility model.

[0035] Figure 6 This is a cross-sectional view (top view) of the filler of the motor rotor according to an embodiment of the utility model.

[0036] Figure 7 This is a cross-sectional view (side view) of the filler of the motor rotor according to an embodiment of the utility model.

[0037] Figure 8 It is a schematic diagram of the three-dimensional structure of the rotating shaft of the motor rotor according to an embodiment of the utility model.

[0038] Fig. 9 This is a schematic diagram of the overall assembly structure of the motor rotor according to an embodiment of the utility model. DETAILED DESCRIPTION

[0039] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0040] This embodiment discloses a range hood, which includes a housing, a fan and a motor for driving the fan to rotate, wherein the motor includes a rotor and a stator, and the rotor is made of Figures 1 to 9 The motor rotor structure shown is realized.

[0041] like Fig. 9 As shown, the motor rotor of this embodiment adopts a rotor-free iron core structure, and the motor rotor includes a combined magnetic steel 1, a rotating shaft 2 and a filler 3, wherein the rotating shaft 2 is arranged in the hollow inner cavity of the rotor body composed of the combined magnetic steel 1, and the filler 3 component is used to fill the gap between the combined magnetic steel 1 and the rotating shaft 2.

[0042] Specifically, Figure 1 As shown, the combined magnetic steel 1 adopts a rotor body with a hollow inner cavity formed by a combination of at least two magnetic steels (that is, the N pole or S pole of the combined magnetic steel 1 is composed of multiple pieces of magnetic steel); this embodiment adopts a one-stage two-piece structure, that is, the combined magnetic steel 1 includes a first magnetic steel 11 and a second magnetic steel 12 that are alternately arranged at intervals, and each pair of the first magnetic steel 11 and the second magnetic steel 12 constitutes a magnetic pole, and the magnetic poles are arranged in the circumferential direction in the order of alternating N poles and S poles, and the magnetization directions between two adjacent groups of magnetic poles are opposite;

[0043] like Figure 2 As shown, the magnetization direction of each magnetic steel in the combined magnetic steel 1 is set to be the angle β formed between the radial center line of the magnetic steel and the tangent of the circle where the magnetic steel is located. In this embodiment, the value range of the angle β is 0°<β<90°.

[0044] The conventional magnetization direction is usually 0 degrees or 90 degrees. In this embodiment, the magnetization direction of each magnet is selected at any angle between 0 and 90 degrees. Compared with the conventional magnetization method, the magnetization direction at a certain angle can improve the sinusoidality and torque density of the air gap magnetic field waveform, that is, reduce the air gap magnetic flux distortion rate and further reduce the risk of vibration and abnormal noise.

[0045] like Figure 3a , Figure 3b As shown, the first magnetic steel 11 is a magnetic steel with a trapezoidal cross section, and the long side 111 of the trapezoidal cross section of the first magnetic steel 11 is arranged inwardly close to the rotating shaft 2, and the short side 112 of the trapezoidal cross section of the first magnetic steel 11 is arranged outwardly away from the rotating shaft 2. The ratio between the width L1 of the short side 112 and the width L2 of the long side 111 is A, and the value range of A is 0<A<1. This unequal side design of the trapezoidal cross section can optimize the torque and pulsating torque of the tooth slot, and improve the average torque to a certain extent.

[0046] like Figure 4a , Figure 4b As shown, the second magnetic steel 12 is a magnetic steel with a fan-shaped cross section, the center o1 of the inner arc 121 of the fan-shaped cross section of the second magnetic steel 12 is the center point of the entire combined magnetic steel 1, the radius of the inner arc 121 is r1, the center o2 of the outer arc 122 of the fan-shaped cross section of the second magnetic steel 12 is eccentric to the center o1 of the inner arc 121, the eccentric distance between the two centers is d, and the radius of the outer arc 122 is r2, that is, r1+d=r2. The eccentric structural design between the outer arc 122 and the inner arc 121 of the second magnetic steel 12 enables the motor to obtain a back electromotive force with high sinusoidality and low harmonic content in the air gap magnetic field, so as to improve the vibration of the motor, and further reduce the risk of abnormal sound generation.

[0047] In addition, a small piece is cut off on both sides of the outer arc 122 of the fan ring section of the second magnetic steel 12 to form a groove 123 that can improve the air gap magnetic field and electromotive force waveform, see Figure 4b The slot 123 structure can improve the air gap magnetic field and electromotive force waveform on the one hand, and on the other hand, when filling, the filler 3 can form a wrapping corner 33 to wrap the second magnetic steel 12, thereby improving the connection strength between the filler 3 and the magnetic steel.

[0048] The surface of the rotating shaft 2 of this embodiment is provided with a plurality of convex strips 21 which are staggered in the axial direction and spaced apart in the circumferential direction, see Figure 8 The convex strip 21 on the surface of the rotating shaft 2 is designed so that the filler 3 can form a groove 34 in the center circumferential direction when filling, see Figure 7 The groove 34 matches with the multiple staggered ridges 21 on the shaft 2 , thereby enhancing the axial and tangential strength between the filler 3 and the shaft 2 .

[0049] The filler 3 can be selected as an integral injection molded part or a glue-filled part, such as Figure 5 to Figure 7 As shown, the filler 3 is formed with a first magnetic steel groove 31 for accommodating the first magnetic steel 11 and a second magnetic steel groove 32 for accommodating the second magnetic steel 12. The filler 3 can fill any air gap and firmly wrap the rotor assembly into a whole. The processing technology is simple and reliable, and the stability is strong. While ensuring the overall structural strength and reliability of the rotor assembly, it also ensures that the rotor assembly runs smoothly under high-speed centrifugal force.

[0050] In order to facilitate processing and manufacturing and improve the processing and assembly efficiency of rotor assembly molding, in terms of preparation method, the rotor assembly processing mold includes a magnetizing module, a positioning module and a filling module. The specific preparation process is: first, the first magnetic steel 11 and the second magnetic steel 12 are magnetized according to the magnetization direction, which can ensure the consistency of the magnetic flux of each magnetic steel, and the magnetization saturation can reach about 98%; then, the magnetized magnetic steel is embedded in the mold cavity for positioning, and arranged to form a ring-shaped combined magnetic steel 1, and the rotating shaft 2 is embedded in the center hole of the mold cavity. The upper and lower molds fix the combined magnetic steel 1 and the rotating shaft 2 in the positioning mold; finally, the filler 3 is injected or glued into the upper and lower mold cavities, and the motor rotor is formed after curing.

[0051] This embodiment adopts an iron coreless motor rotor structure, and the magnetic steel adopts an unconventional magnetization direction of any angle between 0 and 90 degrees, so that the motor obtained by using the magnetic steel has a smaller rotor yoke magnetic density, which is beneficial to reducing the rotor yoke height. The rotor core can be eliminated without affecting the performance, which is beneficial to reducing the moment of inertia and motor weight, and improving the motor torque density and power density.

[0052] In the specification and claims of the present invention, terms indicating directions, such as "front", "rear", "up", "down", "left", "right", "side", "top", "bottom", etc., are used to describe various exemplary structural parts and elements of the present invention, but these terms are used here only for the purpose of convenience of description and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in the present invention can be arranged in different directions, these terms indicating directions are only used as explanations and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

Claims

1. A motor rotor, characterized in that: The motor rotor comprises: Combined magnetic steel (1), composed of at least two types of magnetic steel to form a rotor body with a hollow inner cavity; A rotating shaft (2) is arranged in the hollow inner cavity of a rotor body composed of the combined magnetic steel (1); A filler (3) component, used to fill the gap between the combined magnetic steel (1) and the rotating shaft (2); The magnetization direction of each magnetic steel in the combined magnetic steel (1) is an angle β formed between the radial center line of the magnetic steel and the tangent line of the circle where the magnetic steel is located, and the value range of the angle β is 0°<β<90°.

2. The motor rotor according to claim 1, characterized in that: The combined magnetic steel (1) comprises first magnetic steel (11) and second magnetic steel (12) which are alternately arranged at intervals, wherein each pair of the first magnetic steel (11) and the second magnetic steel (12) constitutes a magnetic pole, the magnetic poles are arranged in a circumferential direction in an alternating order of N poles and S poles, and the magnetization directions of two adjacent groups of magnetic poles are opposite.

3. The motor rotor according to claim 2, characterized in that: The first magnetic steel (11) is a magnetic steel with a trapezoidal cross section, wherein the long side (111) of the trapezoidal cross section of the first magnetic steel (11) is arranged in an inward direction close to the rotating shaft (2), and the short side (112) of the trapezoidal cross section of the first magnetic steel (11) is arranged in an outward direction away from the rotating shaft (2).

4. The motor rotor according to claim 2, characterized in that: The second magnetic steel (12) is a magnetic steel with a fan-shaped cross section. The inner arc (121) of the fan-shaped cross section of the second magnetic steel (12) is arranged in an inward direction close to the rotating shaft (2), and the outer arc (122) of the fan-shaped cross section of the second magnetic steel (12) is arranged in an outward direction away from the rotating shaft (2).

5. The motor rotor according to claim 4, characterized in that: The second magnetic steel (12) is also provided with grooves (123) on both sides of the outer arc (122) of the fan ring cross section, which can improve the air gap magnetic field and electromotive force waveform.

6. The motor rotor according to claim 1, characterized in that: The filler (3) is an integral injection-molded part or a glue-filled part.

7. The motor rotor according to claim 1, characterized in that: The surface of the rotating shaft (2) is provided with a plurality of convex strips (21) which are staggered in the axial direction and distributed at intervals in the circumferential direction.

8. The motor rotor according to claim 1, characterized in that: The motor rotor processing mold includes A magnetizing module, magnetizing the magnetic steel according to a magnetizing direction; A positioning module is used to position each magnetic steel, arrange the magnetic steel in a circumferential direction to form the combined magnetic steel (1), and fix the rotating shaft (2) in the mold cavity; The filling module is used to inject or glue filler (3) into the mold cavity, and after curing, the motor rotor is formed.

9. An electric motor, comprising a rotor and a stator, characterized in that: The rotor is a motor rotor as described in any one of claims 1 to 8.

10. A range hood, comprising a housing, a fan and a motor for driving the fan, characterized in that: The electric motor is the electric motor as claimed in claim 9.

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