Low-noise high-stability large motor

Abstract

The application relates to the technical field of electric machines, in particular to a large-sized electric machine with low noise and high stability, which comprises a stator assembly, a rotor assembly and a heat dissipation cover; the stator assembly comprises a stator core formed by stacking a plurality of stator laminations; a rotor through hole is arranged at the center of the stator core, and a plurality of stator teeth are arranged in the rotor through hole in a ring shape; a winding is arranged on the stator teeth; a front bearing seat and a rear bearing seat are respectively fixedly arranged at the two ends of the stator assembly; the heat dissipation cover is fixedly arranged on the rear bearing seat; a heat dissipation fan is arranged in the heat dissipation cover; the rotor assembly is arranged in the stator assembly and comprises a rotor core formed by stacking a plurality of rotor laminations and a rotor shaft penetrating through the rotor core; the rotor core is provided with a plurality of rotor slots and a plurality of evenly-distributed escape holes in a ring shape; one magnetic steel is arranged in each rotor slot; the two ends of the rotor shaft are rotatably arranged on the front bearing seat and the rear bearing seat through bearings; and the number of the rotor slots is greater than that of the stator teeth. The application can effectively reduce the noise of the large-sized electric machine and improve the stability of the electric machine.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a large motor with low noise and high stability. Background Technology

[0002] The working principle of a permanent magnet motor is that a rotating magnetic field is formed by windings on the stator, and magnets are placed in the rotor. When the magnets are in the rotating magnetic field, they drive the rotor to rotate. During the operation of the motor, the motor will generate a certain amount of noise and vibration due to electromagnetic effects and the rotation of the rotor. In many existing noise reduction motors, vibration damping structures are usually selected to reduce the mechanical vibration of the motor, thereby achieving a certain degree of noise reduction and stability improvement. However, this method is usually more effective in smaller motors. For large motors that are mainly used to provide greater power, the vibration energy of the motor increases, so the vibration reduction and noise reduction effect of additional vibration damping structures will be reduced. A new type of motor structure is needed to achieve the requirements of low noise and high stability for large motors. Summary of the Invention

[0003] This invention provides a large motor with low noise and high stability, which can effectively solve the problems in the background art.

[0004] This invention provides a low-noise, high-stability large motor, comprising:

[0005] The stator assembly includes a stator core formed by stacking multiple stator laminations; a rotor through hole is provided at the center of the stator core, and multiple evenly distributed stator teeth are arranged circumferentially around the rotor through hole; the winding is arranged on the stator teeth.

[0006] The front bearing housing is fixedly mounted at one end of the stator assembly;

[0007] The rear bearing housing is fixedly mounted at the other end of the stator assembly;

[0008] A heat sink is fixedly mounted on the rear bearing housing; a cooling fan is installed inside the heat sink.

[0009] The rotor assembly, disposed in the rotor through hole of the stator assembly, includes a rotor core formed by multiple stacked rotor laminations and a rotor shaft passing through the rotor core; the rotor core is provided with multiple evenly distributed rotor slots in a circumferential direction, and multiple evenly distributed clearance holes in a ring, with the clearance holes being closer to the rotor shaft than the rotor slots; a magnet with the same shape as the rotor slot is placed in each rotor slot; the two ends of the rotor shaft are respectively rotatably mounted on the front bearing housing and the rear bearing housing via bearings;

[0010] The number of rotor slots is greater than the number of stator teeth.

[0011] Furthermore, a first side and a second side are provided at the end of the rotor slot near the rotor shaft. The distance between the first side and the second side gradually increases outward along the radial direction of the rotor core, so that the closest first side and the second side in two adjacent rotor slots are parallel to each other.

[0012] Furthermore, a third side and a fourth side are provided at the end of the rotor slot away from the rotor shaft, which are parallel to each other.

[0013] Furthermore, the first and third sides are coplanar, and the extended surface passes through the central axis of the rotor core.

[0014] Furthermore, the end of the rotor slot furthest from the rotor shaft is provided with an oblique angle, and the oblique angle is connected to the fourth side surface.

[0015] Furthermore, a keyway is provided at the center of the rotor core, with unequal depths on both sides of the keyway.

[0016] Furthermore, a balance through hole is provided on the rotor core, and the balance through hole and the keyway are located on both sides of the rotor core.

[0017] Furthermore, the stator core end is provided with a protective cover whose diameter gradually increases outward; the rotor core end is provided with multiple fan blades arranged in the circumferential direction, and the fan blades are spaced apart from the inner wall of the protective cover and the rotor shaft.

[0018] Furthermore, the multiple fan blades are divided into two groups. The fan blades in the first group are referred to as the first fan blades, and the fan blades in the second group are referred to as the second fan blades. The first fan blades are closer to the rotor shaft than the second fan blades, and the first fan blades and the second fan blades are alternately arranged.

[0019] The technical solution of this invention can achieve the following technical effects:

[0020] This motor optimizes the rotor's magnetic field by improving the rotor lamination structure. By setting clearance holes to limit the magnetic field position and increase its strength, and by setting the number of rotor slots to be greater than the number of stator teeth, the force waves generated during motor operation are transformed from a high-frequency, low-amplitude mode to a low-frequency, high-amplitude mode. Then, the strong structural strength of the large motor itself eliminates the influence of the slightly larger force waves, thereby effectively reducing motor vibration and achieving the requirements of low noise and high stability. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the low-noise, high-stability large motor in this invention;

[0023] Figure 2 This is a side sectional view of the low-noise, high-stability large motor of the present invention;

[0024] Figure 3 This is a schematic diagram of the stator lamination structure in this invention;

[0025] Figure 4 This is a schematic diagram of the rotor lamination structure in this invention;

[0026] Figure 5 In this invention Figure 4 Enlarged view of point B;

[0027] Figure 6 This is a cross-sectional view of the stator assembly and rotor assembly combined in this invention;

[0028] Figure 7 In this invention Figure 2 Enlarged view of point A;

[0029] Figure 8 This is a front view of the first and second blades in this invention.

[0030] Reference numerals: 1. Stator assembly; 11. Stator lamination; 12. Rotor through hole; 13. Stator tooth; 14. Protective cover; 2. Front bearing housing; 3. Rear bearing housing; 4. Heat sink cover; 5. Cooling fan; 6. Rotor assembly; 61. Rotor lamination; 62. Rotor shaft; 63. Rotor slot; 63a. First side; 63b. Second side; 63c. Third side; 63d. Fourth side; 63e. Angled; 64. Clearance hole; 65. Keyway; 66. Balance through hole; 67a. First fan blade; 67b. Second fan blade; 7. Magnet. Detailed Implementation

[0031] The basic principles and main features of the technical solution of the present invention will be described below with reference to the accompanying drawings of the embodiments of the present invention. The following description will use one or more embodiments for a more intuitive understanding. These embodiments are merely some, not all, of the embodiments of the present invention.

[0032] In the description of this invention, the terms indicating orientation or positional relationship (such as up, down, left, right, etc.) are based on the orientation shown in the drawings or some conventional positional relationships, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the features referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0033] This invention provides a large motor with low noise and high stability, such as... Figures 1-2 and Figure 6 As shown, the main body of the motor consists of stator assembly 1, front bearing housing 2, rear bearing housing 3, heat sink 4, rotor assembly 6, and other components. The specific structure of each component is as follows:

[0034] Stator assembly 1 is used to generate a rotating magnetic field. Stator assembly 1 includes a stator core formed by stacking multiple stator laminations 11, each stator lamination 11 having the same shape, such as... Figure 3 As shown, the stator laminations 11 are stacked together along the rotor shaft 62 axially. The stator core formed after stacking has a rotor through hole 12 at its center, and the rotor through hole 12 is provided with multiple evenly distributed stator teeth 13 in the circumferential direction. The windings are arranged on the stator teeth 13, and each stator tooth 13 is wound with a set of coils. The specific winding method of the coils on the stator teeth 13 is the prior art and will not be described in detail here.

[0035] The front bearing housing 2 is fixedly installed at one end of the stator assembly 1; the rear bearing housing 3 is fixedly installed at the other end of the stator assembly 1; both the front bearing housing 2 and the rear bearing housing 3 are provided with connection structures for the motor to connect to the outside world.

[0036] The heat sink 4 is fixedly mounted on the rear bearing seat 3; a cooling fan 5 is installed inside the heat sink 4. The cooling fan 5 is preferably driven by a separate drive mechanism so that the cooling fan 5 can be separated from the rotor shaft 62, so as to avoid the wind resistance encountered by the cooling fan 5 during rotation affecting the smooth rotation of the rotor shaft 62, resulting in motor noise and motor vibration.

[0037] The rotor assembly 6 is disposed in the rotor through-hole 12 of the stator assembly 1 and rotates within the rotating magnetic field. The rotor assembly 6 includes a rotor core formed by stacking multiple rotor laminations 61, and a rotor shaft 62 passing through the rotor core. The rotor laminations 61 are as follows... Figure 4 As shown; the rotor core is provided with multiple evenly distributed rotor slots 63 and multiple evenly distributed clearance holes 64, and the clearance holes 64 are closer to the rotor shaft 62 than the rotor slots 63; a magnet 7 with the same shape as the rotor slot 63 is placed in each rotor slot 63; the rotor shaft 62 is rotatably mounted on the front bearing seat 2 and the rear bearing seat 3 through bearings at both ends.

[0038] In addition to reducing weight, the clearance hole 64 can also effectively control the magnetic circuit in the rotor core. Since the magnetic permeability of iron is much greater than that of air, when the clearance hole 64 is set in the rotor core, the magnetic resistance is increased in the area of ​​the clearance hole 64 that is too close to the rotor shaft 62 and does not need magnetic conduction. In this way, the magnetic flux generated by the magnet 7 will be more concentrated in the outer area of ​​the rotor core. Thus, the magnetic pull force generated by the rotating magnetic field on the rotor core will be more concentrated on the outer side of the rotor core. This not only increases the torque generated by the magnetic pull force, but also effectively avoids rotor core vibration caused by excessive dispersion of magnetic pull force, thereby reducing noise and improving the stability of the motor during operation.

[0039] The number of rotor slots 63 is greater than the number of stator teeth 13, meaning the number of magnets 7 is greater than the number of winding coils. For example, in this embodiment, the ratio of rotor slots 63 to stator teeth 13 is 68 / 60. This achieves better vibration reduction in large motors. The specific principle is as follows: Radial force waves generated during the interaction between the stator and rotor are, in traditional small motor designs, made so that the number of poles (i.e., the number of magnets 7) is equal to or slightly less than the number of winding coils (i.e., the number of stator teeth 13). Although the resulting radial force waves are relatively frequent, their amplitude is small. For small motors, which are lightweight and susceptible to impact, small-amplitude force waves are safer. However, when this… When high-frequency, low-amplitude force waves act on a large motor, these frequent force waves cause the rotor of the large motor to wobble frequently and in an unpredictable manner, resulting in noise. Therefore, in this motor, the number of poles (i.e., the number of magnets 7) is increased to be slightly larger than the number of winding coils (i.e., the number of stator teeth 13). Although this increases the amplitude of the force waves to some extent, it can greatly reduce the frequency of the force waves. Since the motor structure is very large and has high strength, compared with the case of a small motor, the increase in the amplitude of the force waves is far less than the increase in the structural strength of the large motor, while the frequency of the force waves is significantly reduced. Therefore, the motor wobble and noise caused by force waves can be greatly reduced.

[0040] Preferably, a first side surface 63a and a second side surface 63b are provided at one end of the rotor slot 63 near the rotor shaft 62, and the distance between the first side surface 63a and the second side surface 63b gradually increases outward along the radial direction of the rotor core, such as... Figure 5As shown, this arrangement ensures that the closest first side surface 63a and second side surface 63b in two adjacent rotor slots 63 are parallel to each other. This maintains a uniform distance between the first side surface 63a and second side surface 63b, resulting in relatively uniform magnetic field lines formed by the magnets 7 within this distance. Therefore, when the rotating magnetic field rotates, the generated magnetic pull can act evenly across the entire parallel section between the first side surface 63a and second side surface 63b, effectively preventing vibration caused by excessive localized stress on the rotor core. Furthermore, the parallel spacing effectively enhances the mechanical strength of the rotor core, preventing deformation.

[0041] Preferably, a third side surface 63c and a fourth side surface 63d, which are parallel to each other, are provided at the end of the rotor slot 63 away from the rotor shaft 62, such as... Figure 5 As shown, this arrangement allows the closest third side 63c and fourth side 63d of two adjacent rotor slots 63 to form an outwardly expanding shape. This expansion creates a wider corresponding area on both sides of the magnetic bridge at the far-axis end of the two magnets 7, thereby reducing the density of magnetic field lines at this location. The density of magnetic field lines is smaller than that of the parallel section, and it decreases further outward. As a result, the magnetic pull generated by the rotating magnetic field gradually decreases from the inside to the outside. Since the magnetic pull generated by the rotating magnetic field on each magnet 7 is different, without this expansion section, a fault position where the magnetic pull suddenly disappears would be created in the radial direction of the rotor core. This would cause an impact where the magnetic pull suddenly disappears, and the degree of impact at each magnet 7 is different. The more this unbalanced impact occurs in the outer region of the rotor core, the more likely it is to cause the rotor core to wobble. The expansion section ensures that the magnetic pull at each magnet 7 gradually disappears outward, which can, to a certain extent, avoid the unbalanced impact caused by the sudden disappearance of the magnetic pull at the outer edge of the rotor core, thereby ensuring the stability of the rotor core.

[0042] Preferably, an oblique angle 63e is provided at the end of the rotor slot 63 furthest from the rotor shaft 62, and the oblique angle 63e is connected to the fourth side surface 63d. The oblique angle 63e further changes the geometry of the magnetic pole edge, so that the change of magnetic pull tends to change from steep to gradual.

[0043] Preferably, the first side surface 63a and the third side surface 63c are coplanar, and the coplanar surface extends through the central axis of the rotor core, such as... Figure 5As shown, the parallel segments between the magnets 7 are not radially symmetrical about the rotor core, but are offset to one side of the rotor core's radial direction. This creates a certain distance between the magnetic bridge (i.e., the parallel segments) and the radial direction of the rotor core. The rotating magnetic field generated by the winding is radially symmetrical about the rotor core. If the magnetic bridge did not have this offset, there would be a dead point between the rotating magnetic field and the magnet's magnetic field. That is, due to the good matching and overlap between the rotating magnetic field and the magnet's magnetic field, sufficient magnetic pull could not be generated to start the motor. This offset ensures that there is always a certain difference between the rotating magnetic field and the magnet's magnetic field, and they will not overlap. This ensures that sufficient magnetic pull can be generated at any starting position, guaranteeing the motor's rapid start.

[0044] The rotor core and rotor shaft 62 are connected by a key to ensure synchronous rotation between them. When the keyway 65 is set in the center of the rotor core, it is preferable that the two sides of the keyway 65 have different depths. This asymmetrical design makes the two working surfaces of the key and the keyway have different interferences, so that the two sides of the connecting key have asymmetrical prestress. In this way, no matter how the direction of the electromagnetic torque changes, the connecting key is always pressed to one side, avoiding noise and vibration caused by the back and forth shaking of the connecting key in the keyway 65.

[0045] In order to balance the mass of the missing keyway 65 and ensure the smooth rotation of the rotor core, it is preferable to set a balance through hole 66 on the rotor core. The balance through hole 66 and the keyway 65 are located on both sides of the rotor core, so as to achieve the balance of the rotor core with minimal operation.

[0046] In addition to the vibration noise mentioned above, motor noise also includes noise generated by the airflow during motor cooling. Therefore, improving the airflow during motor cooling is one way to eliminate motor noise. In this motor, a protective cover 14 with a gradually increasing diameter is provided at the end of the stator core. The protective cover 14 contains the connection lines between the windings. Multiple fan blades arranged circumferentially are provided at the end of the rotor core, and the fan blades are spaced apart from the inner wall of the protective cover 14 and the rotor shaft 62. Figure 7 As shown, traditional fan blade structures, lacking inner and outer partitions, cause the airflow inside the motor to become highly turbulent, resulting in airflow collisions that generate noise and vibration. By incorporating inner and outer partitions, the turbulent airflow is first thrown into these partitions, creating relative high pressure, before being discharged outside. Under this pressure, a stable airflow, as shown in the diagram, is gradually formed, thus preventing airflow collisions and noise.

[0047] Preferably, the fan blades are divided into two groups. The fan blades in the first group are designated as the first fan blade 67a, and the fan blades in the second group are designated as the second fan blade 67b, such as... Figure 8As shown, the first blade 67a is closer to the rotor shaft 62 than the second blade 67b, and the first blade 67a and the second blade 67b are arranged alternately. In this way, when the rotor core rotates, the airflow between the first blade 67a and the second blade 67b can form an S-shaped flow channel. The airflow can automatically enter the gaps on both sides along the flow channel, instead of being forcibly pushed into the gaps by the blades, thereby further reducing the collision of the airflow with the rotor assembly.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A large motor with low noise and high stability, characterized in that, include: The stator assembly (1) includes a stator core formed by stacking multiple stator laminations (11); a rotor through hole (12) is provided at the center of the stator core, and multiple evenly distributed stator teeth (13) are arranged around the rotor through hole (12); the winding is arranged on the stator teeth (13); The front bearing housing (2) is fixedly disposed at one end of the stator assembly (1); The rear bearing housing (3) is fixedly disposed at the other end of the stator assembly (1); A heat sink (4) is fixedly mounted on the rear bearing seat (3); a cooling fan (5) is installed inside the heat sink (4); The rotor assembly (6) is disposed in the rotor through hole (12) of the stator assembly (1), including a rotor core formed by stacking multiple rotor laminations (61) and a rotor shaft (62) passing through the rotor core; the rotor core is provided with multiple evenly distributed rotor slots (63) in a circumferential manner, and multiple evenly distributed clearance holes (64) in a ring, and the clearance holes (64) are closer to the rotor shaft (62) than the rotor slots (63); a magnet (7) with the same shape as the rotor slot (63) is placed in each rotor slot (63); the two ends of the rotor shaft (62) are respectively rotatably disposed on the front bearing seat (2) and the rear bearing seat (3) through bearings; The number of rotor slots (63) is greater than the number of stator teeth (13); The rotor slot (63) is provided with a first side surface (63a) and a second side surface (63b) at one end near the rotor shaft (62). The distance between the first side surface (63a) and the second side surface (63b) gradually increases outward along the radial direction of the rotor core, so that the closest first side surface (63a) and second side surface (63b) in two adjacent rotor slots (63) are parallel to each other. The rotor slot (63) is provided with a third side surface (63c) and a fourth side surface (63d) that are parallel to each other at one end away from the rotor shaft (62); The rotor slot (63) is provided with an angle (63e) at the end furthest from the rotor shaft (62), and the angle (63e) is connected to the fourth side surface (63d).

2. The low-noise, high-stability large motor according to claim 1, characterized in that, The first side surface (63a) and the third side surface (63c) are coplanar, and the surface extends through the central axis of the rotor core.

3. The low-noise, high-stability large motor according to claim 1, characterized in that, A keyway (65) is provided at the center of the rotor core, and the two sides of the keyway (65) are not of equal depth.

4. The low-noise, high-stability large motor according to claim 3, characterized in that, The rotor core is provided with a balance through hole (66), and the balance through hole (66) and the keyway (65) are located on both sides of the rotor core.

5. The low-noise, high-stability large motor according to claim 1, characterized in that, The stator core end is provided with a protective cover (14) whose diameter gradually increases outward; the rotor core end is provided with a plurality of fan blades arranged in the circumferential direction, and the fan blades are spaced apart from the inner wall of the protective cover (14) and the rotor shaft (62).

6. The low-noise, high-stability large motor according to claim 5, characterized in that, The fan blades are divided into two groups. The fan blades in the first group are referred to as the first fan blade (67a) and the fan blades in the second group are referred to as the second fan blade (67b). The first fan blade (67a) is closer to the rotor shaft (62) than the second fan blade (67b), and the first fan blade (67a) and the second fan blade (67b) are arranged alternately.

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