Rotor assembly, magnetic suspension motor and air blower

Abstract

The invention provides a rotor assembly, a magnetic suspension motor and an air blower, and the rotor assembly comprises two supports which are arranged at an interval; the rotating shaft is arranged between the two supports, the two ends of the rotating shaft face the two supports respectively, the rotating shaft and the supports are arranged in a spaced mode, and the rotating shaft is provided with a through hole penetrating through the two axial ends of the rotating shaft; the supporting shaft is arranged in the through hole in a penetrating mode, and the two ends of the supporting shaft are connected to the support; when the magnetic suspension motor works, the inner wall surface of the through hole is not in contact with the outer wall surface of the supporting shaft, so that the technical problem that a rotating shaft of a magnetic suspension motor in the prior art is relatively low in inherent frequency and cannot realize higher-speed rotation can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic suspension motors, and in particular relates to a rotor assembly, a magnetic suspension motor and a blower. Background Art

[0002] High-speed permanent magnet motors are widely used in different industrial fields due to their simple structure, high power density, no excitation loss, high efficiency and other advantages. With the improvement of motor performance requirements in industrial applications, the design of high-speed permanent magnet motors often presents the characteristics of high operating speed, high power density and high electromagnetic load, which will undoubtedly greatly increase the difficulty of permanent magnet motor design. When the rated speed of the designed rotor becomes higher and higher, the influence of the rotor's natural frequency on the rotor operation becomes more obvious, which will cause the rotor to vibrate more and more obviously, and then make the motor bearing accuracy difficult to control. Therefore, how to improve the rotor's natural frequency is currently a difficult problem.

[0003] High-speed permanent magnet motors have the advantages of small size, high power density and high efficiency. However, since the magnetic levitation high-speed motor IPM rotor is equipped with axial bearings, radial bearings, protective bearings, position sensors, etc., the rotor is too long and the rotor fixed frequency is too small, making it impossible to further increase the rotor speed.

[0004] The existing methods for improving the natural frequency of high-speed permanent magnet motor rotors are: 1. Optimizing the raw materials of the rotor to improve the strength of the rotor material itself, but this method often increases the cost of the rotor sharply; 2. Optimizing the spacing of the rotor assembly parts to make the rotor more compact to improve the rotor fixed frequency, but it will increase the difficulty of motor assembly and the difficulty of installing protective bearings; 3. Adjusting the material of the rotor assembly parts and optimizing the rotor center of gravity to improve the rotor fixed frequency, but the improvement effect is minimal.

[0005] How to effectively improve the natural frequency of the rotor is a technical problem that needs to be solved urgently. Summary of the invention

[0006] Therefore, the present invention provides a rotor assembly, a magnetic levitation motor and a blower, which can solve the technical problem in the prior art that the natural frequency of the rotating shaft of the magnetic levitation motor is low and a higher speed rotation cannot be achieved.

[0007] The present invention provides a rotor assembly, which is applied to a magnetic levitation motor, comprising:

[0008] Two brackets, the two brackets are arranged at intervals;

[0009] A rotating shaft is arranged between the two brackets, with two ends of the rotating shaft facing the two brackets respectively and spaced apart from the brackets, and the rotating shaft is provided with through holes penetrating through the two axial ends thereof;

[0010] A support shaft is inserted into the through hole, and both ends of the support shaft are connected to the bracket;

[0011] When the magnetic levitation motor is working, the inner wall surface of the through hole is not in contact with the outer wall surface of the support shaft.

[0012] In some embodiments, a first bearing is sleeved on the support shaft, and when the magnetic levitation motor is working, the outer circumferential surface of the first bearing does not contact the inner wall surface of the through hole.

[0013] In some embodiments, a first weight-reducing space is disposed at the first end of the through hole, and a second weight-reducing space is disposed at the second end of the through hole.

[0014] In some embodiments, at least two second bearings are sleeved on the support shaft, one second bearing is arranged in the first weight reduction space, and the other second bearing is arranged in the second weight reduction space; when the magnetic levitation motor is working, the outer cylindrical surface of the second bearing does not contact the inner wall surface of the weight reduction space, and when the magnetic levitation motor is not working, the outer cylindrical surface of the second bearing contacts the inner wall surface of the weight reduction space, and the inner wall surface of the through hole does not contact the support shaft.

[0015] In some embodiments, a first radial magnetic levitation rotor and a second radial magnetic levitation rotor are sleeved on the rotating shaft. In the radial direction of the rotating shaft, the first radial magnetic levitation rotor at least partially overlaps with the first weight reduction space, and the second radial magnetic levitation bearing rotor at least partially overlaps with the second weight reduction space.

[0016] In some embodiments, along the axial direction of the rotating shaft, the through hole includes at least a first through hole and a second through hole, and the cross-sectional areas of the first through hole and the second through hole are different.

[0017] In some embodiments, both ends of the support shaft are fixedly connected to the bracket.

[0018] In some embodiments, both ends of the support shaft are connected to the bracket so as to be rotatable around their own axes.

[0019] The present invention also provides a magnetic levitation motor, comprising the rotor assembly according to any one of claims 1 to 8.

[0020] The invention provides a blower, comprising a magnetic suspension motor.

[0021] In some embodiments, the air outlet of the blower is provided with a guide tube, and the outlet of the guide tube leads to the through hole.

[0022] The present invention sets an axial through hole on the rotating shaft, and sets a support shaft in the through hole. When the magnetic levitation motor is working, the rotating shaft does not contact the support shaft, and when the magnetic levitation motor is not working, the rotating shaft falls on the support shaft. Compared with the prior art that requires protective bearings to be set at both ends of the rotating shaft, the present application sets a through hole, which, on the one hand, reduces the weight of the rotating shaft and increases the natural frequency of the rotating shaft; on the other hand, it shortens the axial length of the rotating shaft, optimizes the mass distribution, and can also increase the natural frequency of the rotating shaft. After the natural frequency of the rotating shaft is increased, a higher rotation speed can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. The drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0024] Figure 1 is a schematic diagram of a rotating shaft of an embodiment of the present invention provided with a through hole;

[0025] Figure 2 is a schematic diagram of an embodiment of the present invention when a conical surface is provided;

[0026] Figure 3 is a schematic diagram of a case where a first bearing is provided on the support shaft of an embodiment of the present invention;

[0027] Figure 4 is a schematic diagram of a case where a support shaft is disposed in a through hole of a rotating shaft according to an embodiment of the present invention;

[0028] Figure 5 is a schematic diagram of an embodiment of the present invention when a second bearing is provided;

[0029] The accompanying drawings are marked as follows:

[0030] 1. Rotating shaft; 101. Through hole; 2. Support shaft; 301. First bearing; 302. Second bearing; 401. First weight reduction space; 402. Second weight reduction space; 501. First radial magnetic levitation rotor; 502. Second radial magnetic levitation rotor; 6. Axial bearing; 7. Conical surface. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0033] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0034] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0035] The present invention provides a rotor assembly, a magnetic suspension motor and a blower, which can solve the technical problem in the prior art that the natural frequency of the rotating shaft of the magnetic suspension motor is low and a higher speed rotation cannot be achieved.

[0036] See also Figure 1-5As shown, the present invention provides a rotor assembly, which is applied to a magnetic levitation motor, and includes:

[0037] Two brackets, the two brackets are arranged at an interval;

[0038] A rotating shaft 1 is arranged between two brackets, with two ends of the rotating shaft 1 facing the two brackets and spaced apart from the brackets, and the rotating shaft 1 is provided with through holes 101 penetrating through its two axial ends;

[0039] A support shaft 2 is inserted into the through hole 101, and both ends of the support shaft 2 are connected to the bracket;

[0040] When the magnetic levitation motor is working, the inner wall surface of the through hole 101 is not in contact with the outer wall surface of the support shaft 2 .

[0041] Through the above arrangement, when the magnetic levitation motor is working, the rotating shaft 1 floats up a certain distance under the action of the magnetic levitation bearing and then rotates. At this time, the support shaft 2 is not in contact with the rotating shaft 1, and the support shaft 2 does not affect the rotation of the rotating shaft 1; when the magnetic levitation motor is not working, the magnetic levitation bearing no longer floats the rotating shaft 1, and the rotating shaft 1 falls down onto the support shaft 2. Since the through hole 101 is provided on the rotating shaft 1, the weight of the rotating shaft 1 is reduced, thereby increasing the natural frequency of the rotating shaft 1. In the prior art, protective bearings are arranged at both ends of the rotating shaft 1, and both ends of the rotating shaft 1 are passed through the protective bearings. When the rotating shaft 1 is working, it does not contact the protective bearings. When the rotating shaft 1 is not working, it falls downward on the protective bearings, which makes the axial length of the rotating shaft 1 longer; when the rotating shaft 1 in the present application is not working, it falls on the supporting shaft 2 passed through the through hole 101, which makes the axial length of the rotating shaft 1 of the present application smaller than the axial length of the rotating shaft 1 in the prior art, thereby further reducing the weight of the rotating shaft 1, and then increasing the natural frequency of the rotating shaft 1. After the natural frequency of the rotating shaft 1 is increased, the maximum rotation speed of the rotating shaft 1 can be further increased.

[0042] The two brackets can utilize the structure used to set the protection bearing in the prior art, and the rotating shaft 1 is shortened and set between the two brackets. The supporting shaft 2 is connected to the bracket to bear the rotating shaft 1 that is not working.

[0043] Furthermore, the through hole 101 is a circular hole and is coaxial with the rotating shaft 1 .

[0044] Preferably, Figure 3 and Figure 4 The support shaft 2 is sleeved with a first bearing 301 . When the magnetic levitation motor is working, the outer circumferential surface of the first bearing 301 does not contact the inner wall surface of the through hole 101 .

[0045] By sleeved the first bearing 301 on the support shaft 2, the rotating shaft 1 falls on the first bearing 301 when not working. Due to inertia, the rotating shaft 1 still has a certain rotation speed when not working. When the rotating rotating shaft 1 falls on the first bearing 301, the rotating shaft 1 can drive the outer ring of the first bearing 301 to continue to rotate, avoiding sliding friction, which can not only reduce friction noise and friction vibration, but also reduce the heat generated by friction.

[0046] Furthermore, a plurality of first bearings 301 are provided, for example, four first bearings 301 are evenly arranged; and the cross section of the support shaft 2 is circular.

[0047] Furthermore, an annular vibration-damping layer is arranged between the inner ring of the first bearing 301 and the outer circle of the support shaft 2. When the rotating shaft 1 falls on the first bearing 301, the annular vibration-damping layer plays a vibration-damping role, reduces noise, and also reduces the impact on the inner wall surface of the through hole 101 of the rotating shaft 1, thereby avoiding the inner wall surface of the through hole 101 having different concave and convex structures due to the impact generated when the rotating shaft 1 falls, avoiding the change of the center of gravity of the rotating shaft 1, ensuring the integrity of the inner wall surface of the through hole 101, and further ensuring the rotation balance of the rotating shaft 1.

[0048] Preferably, Figure 1 and Figure 5 As shown, a first weight-reducing space 401 is disposed at the first end of the through hole 101 , and a second weight-reducing space 402 is disposed at the second end of the through hole 101 .

[0049] By providing the first weight reduction space 401 and the second weight reduction space 402 , on the one hand, the weight of the rotating shaft 1 is further reduced and the natural frequency of the rotating shaft 1 is increased; on the other hand, the center of gravity of the rotating shaft 1 is optimized and the natural frequency of the rotating shaft 1 is further increased.

[0050] Preferably, Figure 5 As shown, at least two second bearings 302 are sleeved on the support shaft 2, one of the second bearings 302 is arranged in the first weight reduction space 401, and the other second bearing 302 is arranged in the second weight reduction space 402; when the magnetic levitation motor is working, the outer cylindrical surface of the second bearing 302 does not contact the inner wall surface of the weight reduction space, and when the magnetic levitation motor is not working, the outer cylindrical surface of the second bearing 302 contacts the inner wall surface of the weight reduction space, and the inner wall surface of the through hole 101 does not contact the support shaft 2.

[0051] By arranging two second bearings 302 on the support shaft 2, and the two second bearings 302 are arranged in the weight reduction space, since the weight reduction space is larger, the diameter of the second bearing 302 is also larger, which improves the load-bearing capacity of the second bearing 302. Since the through hole 101 and the support shaft 2 are always not in contact, it is conducive to the flow of air between the support shaft 2 and the through hole 101, which is also conducive to cooling the rotating shaft 1.

[0052] Furthermore, the first weight reduction space 401 and the second weight reduction space 402 are both cylindrical spaces.

[0053] Further, such as Figure 2 As shown, the side wall surface of the first weight reduction space 401 facing the through hole 101 is a conical surface 7, and the small end of the conical surface 7 faces the through hole 101. The conical surface 7 can not only reduce the weight of the shaft 1, but also reduce the concentrated stress and improve the strength of the shaft. The conical surface 7 can also guide the airflow, which is beneficial for air to enter the through hole 101 from the first weight reduction space 401, and is beneficial for cooling the shaft 1.

[0054] Preferably, Figure 1 As shown, a first radial magnetic suspension rotor 501 and a second radial magnetic suspension rotor 502 are sleeved on the rotating shaft 1. In the radial direction of the rotating shaft 1, the first radial magnetic suspension rotor 501 at least partially overlaps with the first weight reduction space 401, and the second radial magnetic suspension bearing rotor at least partially overlaps with the second weight reduction space 402.

[0055] The function of the first radial magnetic suspension shaft and the second radial magnetic suspension bearing is to suspend the rotating shaft 1. The first radial magnetic suspension bearing includes a first radial magnetic suspension rotor 501 fixed on the rotating shaft 1 and a first radial magnetic suspension stator fixed on the bearing seat. Since the first radial magnetic suspension rotor 501 is sleeved on the rotating shaft 1 and at least partially overlaps with the first weight reduction space 401, the first radial magnetic suspension rotor 501 has a wrapping and strengthening effect on the rotating shaft 1, so that the thickness between the inner wall surface of the first weight reduction space 401 and the outer wall surface of the rotating shaft 1 can be reduced, further reducing the weight of the rotating shaft 1, and then increasing the natural frequency of the rotating shaft 1. The second radial magnetic suspension rotor 502 has the same function as the first radial magnetic suspension rotor 501.

[0056] Preferably, along the axial direction of the rotating shaft 1 , the through hole 101 includes at least a first through hole and a second through hole, and the cross-sectional areas of the first through hole and the second through hole are different.

[0057] When the through hole 101 is a circular hole, the aperture of the first through hole is different from the aperture of the second through hole. By making the apertures of the through holes 101 different, the mass distribution of the shaft 1 can be optimized, thereby increasing the natural frequency of the shaft 1 and ultimately increasing the maximum rotation speed of the shaft 1.

[0058] Preferably, both ends of the support shaft 2 are fixedly connected to the bracket.

[0059] The support shaft 2 is fixed on the bracket, which improves the stability of the support shaft 2. When the rotating shaft 1 falls on the support shaft 2, excessive vibration can be avoided. When the rotating shaft 1 moves radially for adjustment, the movement of the rotating shaft 1 is more stable due to the fixed connection.

[0060] Preferably, both ends of the support shaft 2 are connected to the bracket so as to be rotatable around their own axis.

[0061] The two ends of the support shaft 2 are connected to the bracket so that they can rotate around their own axes, so that when the rotating shaft 1 falls on the support shaft 2, the support shaft 2 itself can also rotate around its own axis, reducing the force exerted on the support shaft 2 by the rotation of the rotating shaft 1. When the first bearing 301 is provided, the outer circle of the first bearing 301 rotates with the rotating shaft 1. Considering the impact force and possible jamming generated when the rotating shaft 1 falls on the support shaft 2, the support shaft 2 itself can also rotate around its own axis, which transfers part of the rotation energy of the rotating shaft 1 to the support shaft 2 that can rotate around its own axis, which is conducive to the rapid deceleration of the rotating shaft 1. Specifically, bearings are provided at both ends of the support shaft 2 for connection.

[0062] The present invention also provides a magnetic levitation motor, comprising the rotor assembly.

[0063] The rotor assembly of the magnetic levitation motor further includes an axial bearing 6 disposed on the rotating shaft 1 , and the axial bearing 6 limits the axial direction of the rotating shaft 1 .

[0064] The two brackets may be part of the housing of the magnetic levitation motor, or may be separately arranged in the housing.

[0065] The present invention provides a blower, comprising the magnetic levitation motor.

[0066] Preferably, the air outlet of the blower is provided with a guide pipe, and the outlet of the guide pipe leads to the through hole 101.

[0067] A part of the wind blown by the blower enters the through hole 101 through the guide pipe to cool the rotating shaft 1 .

[0068] It is easy for those skilled in the art to understand that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention. These improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A rotor assembly, applied to a magnetic levitation motor, characterized in that: include: Two brackets, the two brackets are arranged at intervals; A rotating shaft (1) is arranged between the two brackets, with two ends of the rotating shaft (1) facing the two brackets respectively and spaced apart from the brackets, and the rotating shaft (1) is provided with through holes (101) penetrating through its two axial ends; A support shaft (2) is inserted into the through hole (101), and two ends of the support shaft (2) are connected to the bracket; When the magnetic levitation motor is working, the inner wall surface of the through hole (101) and the outer wall surface of the support shaft (2) are not in contact with each other.

2. The rotor assembly according to claim 1, characterized in that: The support shaft (2) is sleeved with a first bearing (301), and when the magnetic levitation motor is working, the outer circumferential surface of the first bearing (301) is not in contact with the inner wall surface of the through hole (101).

3. The rotor assembly according to claim 1, characterized in that: A first weight-reducing space (401) is provided at the first end of the through hole (101), and a second weight-reducing space (402) is provided at the second end of the through hole (101).

4. The rotor assembly according to claim 3, characterized in that: At least two second bearings (302) are sleeved on the support shaft (2), one of the second bearings (302) is arranged in the first weight reduction space (401), and the other second bearing (302) is arranged in the second weight reduction space (402); when the magnetic levitation motor is working, the outer cylindrical surface of the second bearing (302) does not contact the inner wall surface of the weight reduction space; when the magnetic levitation motor is not working, the outer cylindrical surface of the second bearing (302) contacts the inner wall surface of the weight reduction space, and the inner wall surface of the through hole (101) does not contact the support shaft (2).

5. The rotor assembly according to claim 4, characterized in that: A first radial magnetic suspension rotor (501) and a second radial magnetic suspension rotor (502) are sleeved on the rotating shaft (1); in the radial direction of the rotating shaft (1), the first radial magnetic suspension rotor (501) at least partially overlaps with the first weight reduction space (401), and the second radial magnetic suspension bearing rotor at least partially overlaps with the second weight reduction space (402).

6. The rotor assembly according to claim 1, characterized in that Along the axial direction of the rotating shaft (1), the through hole (101) comprises at least a first through hole and a second through hole, and the cross-sectional areas of the first through hole and the second through hole are different.

7. The rotor assembly according to any one of claims 1 to 6, characterized in that: Both ends of the support shaft (2) are fixedly connected to the bracket.

8. The rotor assembly according to any one of claims 1 to 6, characterized in that: Both ends of the support shaft (2) are connected to the bracket in a manner that allows them to rotate around their own axes.

9. A magnetic levitation motor, characterized in that: A rotor assembly comprising any one of claims 1-8.

10. A blower, characterized in that: Including the magnetic levitation motor as described in claim 9.

11. The blower according to claim 10, characterized in that The air outlet of the blower is provided with a flow guide pipe, and the outlet of the flow guide pipe leads to the through hole (101).

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