Magnetic suspension motor composite rotating shaft and magnetic suspension motor

Abstract

The magnetic suspension motor composite rotating shaft comprises a rotating shaft body, a magnetic isolation ring, a magnetic steel strip and a sheath, the rotating shaft body is provided with a plurality of shaft sections which are sequentially arranged along the axial direction of the rotating shaft body, the outer diameters of the adjacent shaft sections are different, and one shaft section in the middle of the rotating shaft body is a magnetic steel installation section; the magnetic isolation rings are fixedly arranged on the outer ring of the magnetic steel installation section in a sleeving mode, a magnetic steel installation space is formed between the two magnetic isolation rings, notches are evenly distributed in the opposite end faces of the two magnetic isolation rings in the circumferential direction, the multiple magnetic steel strips are evenly distributed on the outer circumferential face of the magnetic steel installation section, and the extending direction of the magnetic steel strips is parallel to the axial direction of the rotating shaft body. Two ends of the magnetic steel strip are respectively inserted into the notches; and the sheath coaxially sleeves the outer rings of the magnetic steel strips and the magnetic isolation ring. According to the utility model, the gap between the magnetic steel and the rotating shaft body can be utilized to reduce the probability of heat transfer from the magnetic steel to the rotating shaft body, and the heat dissipation effect can be improved by cooperating with the air holes of the sheath.

Description

Technical Field

[0001] The present application belongs to the field of motor technology, and in particular relates to a magnetic levitation motor composite shaft and a magnetic levitation motor. Background Art

[0002] In the related technical solution, the magnetic levitation motor includes an integrally formed shaft, on the outer circumferential surface of which a permanent magnet is attached to form a composite shaft structure. The composite shaft as a whole is used as the rotor of the motor, and no additional iron core is required to be provided and magnetic steel is inserted into the iron core.

[0003] The inventors learned that the rotating shaft includes a rotating shaft body, and a number of magnets are arranged outside the rotating shaft body. The magnets are separated by magnetic isolation bridges, and the outer side of the magnets is fixed with a sheath such as a carbon fiber sleeve or a non-magnetic metal sleeve. As the power of the permanent magnet motor increases, the radius of the rotating shaft also increases, so the centrifugal force on the magnets also increases geometrically. In order to prevent the magnets from being thrown out, the thickness of the carbon fiber sleeve or the non-magnetic metal sleeve must also be increased, but the heat dissipation capacity will decrease. In addition, the harmonic magnetic field generated by the stator can pass through the carbon fiber sleeve or the non-magnetic metal sleeve, causing the magnets to heat up, resulting in the performance of the magnets being reduced or even demagnetized due to the high temperature. The more powerful the motor, the more so.

[0004] In the relevant technical solutions, as shown in the attached Figure 4 As shown in Chinese patent application CN109888953A, in order to cool down the magnetic steel in the sheath of the composite shaft, a blind hole is opened at one end of the shaft, and the blind hole is connected to the outside of the shaft through an oblique ventilation hole, thereby achieving ventilation and cooling inside the shaft to indirectly reduce the temperature of the magnetic steel.

[0005] However, in the above technical solution, the airflow outside the sheath and the airflow inside the shaft cannot directly contact the magnetic steel, so the indirect cooling efficiency is low and the effect is not good.

[0006] It should be noted that the above contents belong to the technical knowledge of the inventor and do not necessarily constitute prior art. Utility Model Content

[0007] The utility model aims to provide a magnetic levitation motor composite shaft and a magnetic levitation motor, which can improve the heat dissipation efficiency of the magnetic steel position of the composite shaft.

[0008] In order to solve the above problems, in the first aspect, the utility model provides a composite shaft of a magnetic suspension motor, comprising a shaft body, a magnetic isolation ring, a magnetic steel bar and a sheath, wherein the shaft body has a plurality of shaft sections arranged in sequence along its own axial direction, and the outer diameters of adjacent shaft sections are different, and a shaft section in the middle of the shaft body is a magnetic steel installation section;

[0009] There are two magnetic isolation rings, which are fixedly mounted on the outer ring of the magnetic steel installation section. A magnetic steel installation space is formed between the two magnetic isolation rings. The opposite end faces of the two magnetic isolation rings are respectively provided with grooves evenly distributed along the circumferential direction. The grooves penetrate the outer ring surface of the magnetic isolation ring but do not penetrate the inner ring surface of the magnetic isolation ring.

[0010] There are multiple magnetic steel strips and they are evenly distributed along the outer circumference of the magnetic steel installation section. The extension direction of the magnetic steel strip is parallel to the axial direction of the rotating shaft body. The two ends of the magnetic steel strip are respectively inserted into two relatively arranged slots. The magnetic steel strip has an arc surface, and the arc surface is flush with the outer circumferential surface of the magnetic isolation ring, so that there is a gap between the magnetic steel strip and the magnetic steel installation section. The sheath is a porous structure, and the sheath is coaxially sleeved on the outer ring of the magnetic steel strip and the magnetic isolation ring. The beneficial effects of one or more of the above technical solutions are:

[0011] (1) Compared with the prior art method of directly sticking the magnetic steel to the outer side of the rotating shaft: in this solution, the magnetic isolation ring is fixed at the magnetic steel installation section, and a notch is set at the magnetic isolation ring. The two ends of the magnetic steel strip are respectively inserted into the two matching notches in the two magnetic steel rings to achieve the axial positioning of the magnetic steel strip along the rotating shaft. The sheath set on the magnetic isolation ring and the outside of the magnetic steel strip is used to achieve the circumferential positioning of the magnetic steel strip along the rotating shaft, so that the magnetic steel can be stably fixed on the surface of the rotating shaft body. This setting method does not need to use gluing or other methods to directly fix the magnetic steel to the rotating shaft body, which is convenient for subsequent disassembly and replacement.

[0012] (2) In this solution, on the basis of using the magnetic isolation ring and the sheath to fix the magnetic steel strip, the slot penetrates the outer ring surface of the magnetic isolation ring but does not penetrate the inner ring surface of the magnetic isolation ring. When the magnetic steel strip is plugged into the slot, there is a gap between the magnetic steel strip and the outer circular side surface of the shaft body. At the same time, there is also a gap between adjacent magnetic steel strips along the axial direction of the shaft body, so that most of the side surfaces of the magnetic steel strip can be exposed to the gap position and connected to the outside world through the porous structure of the sheath, so that the airflow passes through the sides of the magnetic steel strip to take away the corresponding heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present application and do not constitute improper limitations on the present invention.

[0014] Figure 1 It is a half-section schematic diagram of the composite rotating shaft in the utility model;

[0015] Figure 2 for Figure 1 A schematic diagram of the structure of part A in the middle;

[0016] Figure 3 It is a schematic diagram of the end face of the magnetic ring of the utility model;

[0017] Figure 4 It is a schematic diagram of the internal structure of a magnetic levitation motor in the prior art.

[0018] Among them, 1. shaft body; 101. magnetic steel installation section; 102. magnetic isolation ring; 1011. slot; 103. magnetic steel bar; 104. gap; 106. sheath; 1061. air hole; 107. support end; 108. output end; 109. blind hole; 110. through hole; 111. fan blade; 112. shoulder section. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the overall concept of the present application, a detailed description is given below in an illustrative manner in conjunction with the accompanying drawings.

[0020] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] like Figure 4 As shown, in the prior art, in order to cool down the magnetic steel in the sheath of the composite shaft, a blind hole is opened at one end of the shaft, and the blind hole is connected to the outside of the shaft through an oblique ventilation hole, thereby achieving ventilation and cooling inside the shaft to indirectly reduce the temperature of the magnetic steel.

[0022] Example 1

[0023] like Figure 1-Figure 3 As shown, this embodiment provides a composite shaft of a magnetic levitation motor, including a shaft body 1, a magnetic isolation ring 102, a magnetic steel strip 103 and a sheath 106. The shaft body 1 has a plurality of shaft sections arranged in sequence along its own axial direction, and the outer diameters of adjacent shaft sections are different. A shaft section in the middle of the shaft body 1 is a magnetic steel installation section 101. There are two magnetic isolation rings 102, and the magnetic isolation rings 102 are respectively fixedly sleeved on the outer ring of the magnetic steel installation section 101, and a magnetic steel installation space is formed between the two magnetic isolation rings 102. The opposite end faces of the two magnetic isolation rings 102 are respectively provided with notches 1011 evenly distributed along the circumferential direction, and the notches 1011 penetrate the outer annular surface of the magnetic isolation ring 102 but do not penetrate the inner annular surface of the magnetic isolation ring 102.

[0024] There are multiple magnetic steel strips 103 and they are evenly distributed along the outer circumference of the magnetic steel mounting section 101. The extension direction of the magnetic steel strips is parallel to the axial direction of the rotating shaft body 1. The two ends of the magnetic steel strips 103 are respectively inserted into two oppositely arranged slots 1011. The magnetic steel strips 103 have an arc surface, and the arc surface is flush with the outer circumferential surface of the magnetic isolation ring 102, so that there is a gap between the magnetic steel strips 103 and the magnetic steel mounting section 101. The sheath 106 is a porous structure, and the sheath 106 is coaxially sleeved on the outer ring of the magnetic steel strips 103 and the magnetic isolation ring 102.

[0025] Specifically, the cross section of the rotating shaft body 1 is circular. Generally, the outer diameter of the magnetic steel installation section 101 on which the magnetic isolation ring 102 and the magnetic steel strip 103 are installed is basically the largest or second largest section among the shaft sections. In this embodiment, the shaft section of the magnetic steel installation section 101 at one end along the axial direction of the rotating shaft body 1 is a shaft shoulder section 112, and the shaft shoulder section 112 is convenient for stopping against one of the magnetic steel rings, so as to facilitate the positioning of the magnetic steel ring and the magnetic steel strip 103 along one end of the axial direction of the rotating shaft body 1.

[0026] Specifically, corresponding air holes 1061 may also be provided on the magnetic isolation ring 102 to increase the heat dissipation capacity of the magnetic isolation ring 102 and the magnetic steel strip 103 .

[0027] In this embodiment, one end of the shaft body 1 is the output end 108, and the other end is the support end 107. The shaft body 1 has a blind hole 109 arranged along the axial direction and extending from the support end 107 to the center of the shaft. The blind hole 109 extends to at least one of the two magnetic steel rings away from the support end 107. One end of the blind hole 109 away from the support end 107 is respectively connected to a plurality of through holes 110, and the through holes 110 are directly opposite to the gap between the magnetic steel bar 103 and the magnetic steel mounting section 101.

[0028] Specifically, when in use, the output end 108 of the shaft body 1 is generally located outside the magnetic levitation motor, and is used to connect structures such as blades to be driven. The support end 107 of the shaft body 1 is generally located inside the magnetic levitation motor, and is used to connect to the bearing seat to achieve positioning support. In the case of using the blind hole 109, an airflow path can be formed by the external space of the shaft, the support end 107, the blind hole 109, the through hole 110, and the external space of the shaft, so that the heat dissipation of the shaft can be achieved by using the airflow.

[0029] In this embodiment, a plurality of blades 111 are fixed to the outer circumferential surface of the magnetic steel mounting section 101, and the shape of the blades 111 is set to: when the blades 111 rotate, an airflow from the support end 107 to the output end 108 can be formed. Specifically, the shape and size of the blades 111 can be set by those skilled in the art as needed, as long as an airflow in the desired direction can be formed during the rotation around the axis of the shaft body 1. When the blades 111 are provided, the direction of the airflow is: the airflow first flows from the position of the blades 111 to the position of the through hole 110 on one side of the output end 108. During the flow process, negative pressure is formed on the outer annular surface of the shaft body 1, the gap between the shaft body 1 and the magnetic steel strip 103, and the gap between adjacent magnetic steel strips, which will also generate airflow disturbances to increase the heat dissipation effect of the magnetic steel strip 103.

[0030] In this embodiment, the cross section of the blind hole 109 is circular, and the blind hole 109 is a bell mouth at one end that passes through the shaft body 1 , and the bell mouth gradually becomes larger in a direction approaching the supporting end 107 .

[0031] In this embodiment, the surface of the magnetic steel strip 103 facing the magnetic steel installation section 101 and the fan blade 111 is an inner arc surface, and the inner arc surface is coaxial with the magnetic steel installation section 101. In this arrangement, the gap thickness between the magnetic steel strip 103 and the outer cylindrical surface of the shaft body 1 is basically a constant value, which facilitates the uniform heat dissipation of the magnetic steel strip 103.

[0032] In this embodiment, the gaps between adjacent magnetic steel strips 103 form magnetic isolation grooves, and the air holes 1061 on the sheath 106 are at least connected to each magnetic isolation groove. In this arrangement, the magnetic isolation grooves can prevent the formation of eddy currents along the circumference of the shaft body 1 by the multiple magnetic steel strips 103, thereby reducing heat generation. At the same time, the air holes 1061 on the sheath 106 are connected to the magnetic isolation grooves in a manner that can effectively connect the external environment of the shaft with the gap between the magnetic steel strips 103 and the outer circumferential side of the shaft body 1.

[0033] In some other embodiments, in order to avoid the formation of eddy currents, the magnetic steel strip is divided into multiple sections along the length direction, and adjacent sections are fixed by gluing. In order to prevent the sheath from deforming the magnetic steel strip, a supporting protrusion (not shown in the figure) is provided at the gap between the outer circumference of the shaft body and the magnetic steel strip, and the supporting protrusion abuts each section of the magnetic steel strip.

[0034] In this embodiment, the cross section of the air hole 1061 is circular, and the extension direction of the air hole 1061 is not perpendicular to the axial angle of the shaft body 1. This arrangement is convenient for increasing the length of the air hole 1061, thereby increasing the surface area of ​​the air hole 1061, so as to increase the contact area between the airflow at the position of the air hole 1061 and the magnetic steel strip 103, thereby improving the heat dissipation effect.

[0035] In this embodiment, a glue bonding layer is provided between the magnetic isolation ring 102 and the magnetic steel installation section 101. In other embodiments, the magnetic isolation ring 102 is fixed to the magnetic steel installation section 101 of the shaft body 1 by welding, bolt connection or clamping.

[0036] Example 2

[0037] This embodiment also provides a magnetic levitation motor, including the magnetic levitation motor composite shaft in Embodiment 1, and also including a motor housing and a stator fixed to the inner wall surface of the motor housing.

[0038] In this embodiment, an exhaust hole is provided on the side wall of the motor housing, and the exhaust hole is opposite to the blind hole 109 that passes through one end of the rotating shaft body 1. A fan connected to the exhaust hole is provided on the outside of the motor housing; an air inlet is also provided on the outer wall of the motor housing, and the air inlet is opposite to the magnetic steel mounting section 101 and the fan blades 111.

[0039] When in use, the exhaust fan draws air from one end of the blind hole 109 where the through hole 110 is provided toward the supporting end 107 , so as to cooperate with the fan blade 111 and the air inlet near the fan blade 111 to form a directional airflow.

[0040] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A magnetic levitation motor composite shaft, characterized in that: include: The rotating shaft body has a plurality of shaft segments arranged in sequence along its axial direction, and the outer diameters of adjacent shaft segments are different. A shaft segment in the middle of the rotating shaft body is a magnetic steel installation segment; There are two magnetic isolation rings, which are fixedly sleeved on the outer ring of the magnetic steel installation section, respectively, and a magnetic steel installation space is formed between the two magnetic isolation rings. The opposite end faces of the two magnetic isolation rings are respectively provided with notches evenly distributed along the circumferential direction, and the notches penetrate the outer ring surface of the magnetic isolation ring but do not penetrate the inner ring surface of the magnetic isolation ring; There are multiple magnetic steel bars, which are evenly distributed along the outer circumference of the magnetic steel installation section. The extension direction of the magnetic steel bars is parallel to the axial direction of the rotating shaft body. The two ends of the magnetic steel bars are respectively inserted into two oppositely arranged slots. The magnetic steel bars have an arc surface, and the arc surface is flush with the outer circumferential surface of the magnetic isolation ring, so that there is a gap between the magnetic steel bars and the magnetic steel installation section. The sheath is a porous structure and is coaxially sleeved on the outer ring of the magnetic steel strip and the magnetic isolation ring.

2. The magnetic levitation motor composite shaft according to claim 1, characterized in that: One end of the shaft body is the output end, and the other end is the support end. The shaft body has a blind hole arranged along the axial direction and extending from the support end to the center of the shaft. The blind hole extends to at least one of the two magnetic steel rings away from the support end. One end of the blind hole away from the support end is connected to a plurality of through holes respectively, and the through holes are opposite to the gap between the magnetic steel bar and the magnetic steel mounting section.

3. The magnetic levitation motor composite shaft according to claim 2, characterized in that: A plurality of fan blades are fixed to the outer circumferential surface of the magnetic steel mounting section, and the shape of the fan blades is set to form an airflow from the support end to the output end when the fan blades rotate.

4. The magnetic levitation motor composite shaft according to claim 2, characterized in that: The cross section of the blind hole is circular, and one end of the blind hole that passes through the rotating shaft body is a bell mouth, and the bell mouth gradually becomes larger in a direction close to the supporting end.

5. The magnetic levitation motor composite shaft according to claim 1, characterized in that: The surface of the magnetic steel strip facing the magnetic steel installation section and the fan blade is an inner arc surface, and the inner arc surface is coaxial with the magnetic steel installation section.

6. The magnetic levitation motor composite shaft according to claim 1, characterized in that: Magnetic isolation grooves are formed between adjacent magnetic steel strips, and the air holes on the sheath are at least connected to each magnetic isolation groove.

7. The magnetic levitation motor composite shaft according to claim 6, characterized in that: The cross section of the air hole is circular, and the extension direction of the air hole is not perpendicular to the axial angle of the rotating shaft body.

8. The magnetic levitation motor composite shaft according to claim 1, characterized in that: A glue bonding layer is provided between the magnetic isolation ring and the magnetic steel installation section.

9. A magnetic levitation motor, characterized in that: The invention comprises the composite rotating shaft of the magnetic levitation motor as described in any one of claims 1 to 8, and also comprises a motor housing and a stator fixed to the inner wall surface of the motor housing.

10. The magnetic levitation motor according to claim 9, characterized in that: The side wall of the motor housing is provided with an air extraction hole, the air extraction hole is directly opposite to one end of the blind hole penetrating the rotating shaft body, and the outside of the motor housing is provided with a fan connected to the air extraction hole; The outer wall of the motor housing is also provided with an air inlet, and the air inlet is directly opposite to the magnetic steel installation section.

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