Motor and cooling fan

Abstract

The utility model relates to a motor and a cooling fan. Wherein the motor comprises a shaft core, a bearing, a middle pipe, a coil and magnetic groups, the shaft core and the bearing are arranged in the middle pipe, the shaft core is sleeved with the bearing, the middle pipe is sleeved with the coil, the multiple magnetic groups are evenly arranged around the coil, and the shaft core and the middle pipe are both insulators. As the shaft core is an insulator, even if a magnetic field is unbalanced during operation of the motor, the shaft core does not generate shaft voltage and does not transmit the shaft voltage to the bearing, so that the problem of electric corrosion of the bearing can be reduced. In addition, the shaft core is an insulator, so that when the motor operates, the generation of shaft voltage caused by static electricity generated by friction between the shaft core and a bearing or air and the like can be reduced. In addition, as the middle tube is also an insulator, shaft voltage and common-mode voltage which are generated by external interference and are conducted to the bearing can be reduced. Therefore, the problem of electric corrosion of the bearing in the motor can be reduced.

Description

Technical Field

[0001] This application relates to the field of fan technology, and in particular to an electric motor and a cooling fan. Background Technology

[0002] In some electric motors, such as those used in cooling fans, bearings are prone to electrolytic corrosion when used in high-frequency switching or high-power equipment due to various factors. The causes of electrolytic corrosion generally include the generation of shaft voltage and the introduction of common-mode voltage. Shaft voltage is generated by factors such as magnetic field imbalance, external interference, and static electricity buildup, while common-mode voltage is usually caused by the rapid switching action of power semiconductor devices in the equipment.

[0003] In related technologies, to address the cause of magnetic field imbalance, highly precise manufacturing processes are generally employed to improve the symmetry of the motor's magnetic assembly, coils, bearings, and shaft, thereby enhancing the balance of the magnetic field during motor operation. However, this solution is costly and fails to resolve the electro-corrosion problems caused by external interference, self-static accumulation, and the introduction of common-mode voltage. To address electro-corrosion caused by external interference, self-static accumulation, and the introduction of common-mode voltage, related technologies typically involve coating the shaft or intermediate tube with an insulating layer such as grease or oxide, or adding an insulator between the shaft and the intermediate tube. However, these solutions rely on the performance of the insulating layer or insulator. If the insulating layer or insulator wears down to the point that its insulation impedance is less than the shaft voltage's breakdown voltage, the bearing will be electro-eroded by discharge, thus the electro-corrosion problem persists. Utility Model Content

[0004] In view of the above, it is necessary to provide an electric motor and a cooling fan that can reduce the problem of bearing electro-corrosion.

[0005] The first aspect of this application provides an electric motor, including a shaft, a bearing, a middle tube, a coil, and a magnetic assembly. The shaft and the bearing are disposed within the middle tube, the bearing is sleeved on the shaft, the coil is sleeved on the middle tube, and a plurality of magnetic assemblies are evenly arranged around the coil. Both the shaft and the middle tube are insulators.

[0006] In the electric motor of this application, since the shaft core is an insulator, even if there is an imbalance in the magnetic field during motor operation, the shaft core will not generate shaft voltage, nor will it be conducted to the bearing, thereby reducing the problem of bearing electrolytic corrosion. Furthermore, since the shaft core is an insulator, the generation of shaft voltage due to static electricity caused by friction between the shaft core and the bearing or air during motor operation is reduced. Additionally, since the intermediate tube is also an insulator, the conduction of shaft voltage and common-mode voltage caused by external interference to the bearing is reduced. Therefore, this application reduces the problem of bearing electrolytic corrosion in electric motors.

[0007] In some embodiments, the bearing includes a first bearing and a second bearing, which are respectively sleeved on both ends of the shaft core. In this case, when the motor is running, the shaft core and the middle tube are supported by the first and second bearings, which can improve the stability of the relative rotation between the shaft core and the middle tube.

[0008] In some embodiments, the electric motor further includes an elastic element, which is sleeved on the shaft core and its two ends are respectively connected to a first bearing and a second bearing. In this case, the elastic element can maintain a predetermined distance between the first bearing and the second bearing, and can also reduce the vibration of the first bearing or the second bearing during rotation by utilizing its elasticity, thereby further improving the stability of the relative rotation of the shaft core and the central tube.

[0009] In some embodiments, the elastic element is a conductor. In this case, the charge of the first bearing or the second bearing can be conducted by the elastic element, thereby making the potentials of the first bearing and the second bearing the same, which can reduce the possibility of discharge erosion caused by the potential difference between the first bearing and the second bearing.

[0010] In some embodiments, the shaft core comprises a material selected from zirconium oxide, aluminum oxide, silicon nitride, or silicon carbide. In this case, using a material selected from zirconium oxide, aluminum oxide, silicon nitride, or silicon carbide can create a shaft core that is wear-resistant, corrosion-resistant, has a low coefficient of thermal expansion, is high-temperature resistant, and has high insulation properties. This can both extend the service life of the shaft core and reduce the problem of bearing electrolytic corrosion caused by shaft voltage.

[0011] In some embodiments, the tube is made of a liquid crystal polymer or a polyphenylene sulfide. In this case, a heat-resistant, dimensionally stable, and highly insulating tube can be formed using a liquid crystal polymer or a polyphenylene sulfide. This provides stable support for the coil and improves stability. Furthermore, it reduces the conduction of shaft voltage or common-mode voltage caused by electrical signal interference in the coil to the bearing, thereby reducing the problem of bearing electrolytic corrosion.

[0012] In some embodiments, the electric motor further includes an upper housing having a rotor mounting portion and a magnetic assembly mounting portion. The rotor mounting portion is used to mount the shaft core, and the magnetic assembly mounting portion is used to mount the magnetic assembly. In this case, the upper housing, shaft core, and magnetic assembly can form a stable whole to maintain stability when operating as the rotor portion of the electric motor.

[0013] In some embodiments, the motor further includes a lower housing with a stator mounting portion for mounting a center tube. In this case, the lower housing, center tube, and coils can form a stable whole to maintain stability when operating as the stator portion of the motor.

[0014] In some embodiments, the electric motor further includes a circuit assembly fitted onto the stator mounting portion and electrically connected to the coil. In this case, the circuit assembly can apply an electrical signal to the coil to control the magnetic field of the coil, thereby controlling the operation of the electric motor.

[0015] A second aspect of this application also provides a cooling fan, including any of the electric motors provided in the first aspect of this application.

[0016] In the cooling fan of this application, since the motor shaft is an insulator, even if there is an imbalance in the magnetic field during motor operation, the shaft will not generate shaft voltage, nor will it be conducted to the bearing, thereby reducing the problem of bearing electrolytic corrosion. Furthermore, since the motor shaft is an insulator, the generation of shaft voltage due to static electricity caused by friction between the shaft and the bearing or air during motor operation is reduced. Additionally, since the motor's tube is also an insulator, the conduction of shaft voltage and common-mode voltage caused by external interference to the bearing is reduced. Moreover, the first and second bearings of the motor are connected by an elastic element, and this elastic element is conductive. In this case, the charge of the first or second bearing can be conducted through the elastic element, thereby ensuring that the potentials of the first and second bearings are the same, reducing the possibility of discharge corrosion caused by potential differences between the first and second bearings. Therefore, this application reduces the problem of bearing electrolytic corrosion. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the electric motor according to an embodiment of this application.

[0018] Figure 2 This is a schematic diagram of the cooling fan structure according to an embodiment of this application.

[0019] Explanation of key component symbols:

[0020] 1. Cooling fan; 11. Motor; 12. Fan blade; 13. Outer frame; 111. Shaft core; 112. Bearing; 113. Middle tube; 114. Coil; 115. Magnetic assembly; 116. Elastic element; 117. Upper housing; 118. Lower housing; 119. Circuit assembly; First bearing 1121; Second bearing 1122.

[0021] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0022] In the description of the embodiments in this application, the words "exemplary," "or," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary," "or," and "for example" is intended to present the relevant concepts in a specific manner.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this application's specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. It should be understood that, unless otherwise stated, " / " in this application means "or". For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. "At least one" refers to one or more. "More than one" refers to two or more. For example, at least one of a, b, or c can represent: a, b, c, a and b, a and c, b and c, and a, b, and c (seven cases).

[0024] It should also be noted that the terms "first" and "second" in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0025] In some electric motors, such as those used in cooling fans, the metal bearings are prone to electrochemical corrosion when used in high-frequency switching or high-power equipment due to various factors. Electrochemical corrosion, also known as "electrochemical corrosion," typically manifests as follows: In low-level corrosion, the ball bearings turn black and lose their shine; in moderate corrosion, pits appear on the inner and outer raceways, causing abnormal noises during operation; in high-level corrosion, wavy lines appear on the inner and outer raceways, the raceways are damaged, and there is severe abnormal noise and a rapid rise in temperature; in severe corrosion, the bearing is completely damaged, its lifespan ends, and it becomes inoperable. The causes of bearing electrochemical corrosion generally include the generation of shaft voltage and the introduction of common-mode voltage. The generation of shaft voltage is further caused by factors such as magnetic field imbalance, external interference, and the accumulation of static electricity within the bearing itself.

[0026] Magnetic field asymmetry, also known as magnetic circuit asymmetry, includes asymmetry caused by design errors in motor design such as rotor diameter, stator diameter, and rotor-stator coaxiality; asymmetry caused by dimensional accuracy, coil density, coil uniformity, and coil symmetry of various components during motor manufacturing; and asymmetry caused by phase-to-phase equivalent impedance deviations due to inconsistencies in materials and manufacturing processes. Static electricity accumulation typically occurs when the motor shaft, during high-speed operation, continuously rubs against air and other substances, generating static electricity that accumulates into voltage. When this voltage exceeds the withstand voltage of the oil film between the balls and raceways in the bearing, discharge occurs, causing bearing corrosion. Shaft voltage generated by external interference is usually due to interference from external high-frequency converters or pulses when the motor is energized. Common-mode voltage is typically introduced when the motor is used in high-frequency switching or high-power equipment, caused by the rapid switching action of power semiconductor devices in the equipment.

[0027] In related technologies, to address the cause of magnetic field imbalance, highly precise manufacturing processes are generally employed to improve the symmetry of the motor's magnetic assembly, coils, bearings, and shaft, thereby enhancing the balance of the magnetic field during motor operation. However, this approach is costly, and the causes of electro-corrosion also include external interference, self-static accumulation, and the introduction of common-mode voltage. Therefore, this approach still fails to solve the electro-corrosion problem caused by external interference, self-static accumulation, and the introduction of common-mode voltage. To address the electro-corrosion problem caused by external interference, self-static accumulation, and the introduction of common-mode voltage, related technologies still use metal to fabricate components such as the shaft and central tube to maintain stability. Then, the problem is solved by coating the shaft or central tube with insulating layers such as grease or oxides, or by adding an insulator between the shaft and central tube. However, these solutions rely on the performance of the insulating layer or insulator. If the insulating layer or insulator wears down to the point that its insulation impedance is less than the breakdown voltage of the shaft voltage, the bearing will be burned by electrical discharge, thus the problem of electro-corrosion persists.

[0028] Therefore, this application provides an electric motor and a cooling fan that can reduce the problem of bearing electro-corrosion.

[0029] Figure 1 This is a schematic diagram of the structure of the electric motor 11 according to an embodiment of this application.

[0030] Please see Figure 1This application first provides an electric motor 11, which can be used in a cooling fan, meaning the electric motor 11 of this application embodiment can be used in high-temperature environments. The electric motor 11 may include a shaft core 111, a bearing 112, a central tube 113, a coil 114, and magnetic assemblies 115. The shaft core 111 and bearing 112 are disposed within the central tube 113, with the bearing 112 sleeved on the shaft core 111. The coil 114 is sleeved on the central tube 113, and multiple magnetic assemblies 115 are evenly arranged around the coil 114. In the electric motor 11 of this application embodiment, both the shaft core 111 and the central tube 113 are insulators. In this case, since the shaft core 111 is an insulator, the problem of electro-corrosion of the bearing 112 caused by magnetic field imbalance can be reduced. Furthermore, since the shaft core 111 is an insulator, the generation of shaft voltage caused by static electricity generated by friction between the shaft core 111 and the bearing 112 or air during operation can be reduced. Furthermore, since the intermediate tube 113 is also an insulator, the shaft voltage and common-mode voltage generated by external interference can be reduced from being conducted to the bearing 112. Therefore, this application can reduce the problem of electro-corrosion of the bearing 112 in the motor 11.

[0031] It is understandable that even if there is an imbalance in the magnetic field when the motor 11 is running, since the shaft core 111 is an insulator, it will not generate shaft voltage and will not be conducted to the bearing 112. This reduces the problem of electro-corrosion of the bearing 112, that is, it reduces the problem of electro-corrosion of the bearing 112 caused by the imbalance of the magnetic field. It also reduces the generation of shaft voltage due to static electricity generated by friction between the shaft core 111 and the bearing 112 or air. Because the shaft core 111 is an insulator, the static electricity generated by friction between the shaft core 111 and the bearing 112 or air is less, and there is no conductor to conduct the static charge on the shaft core 111. Therefore, it reduces the problem of electro-corrosion caused by shaft voltage generated by the accumulation of static electricity. The shaft voltage and common-mode voltage caused by external interference are reduced from being conducted to the bearing 112. Since the middle tube 113 is an insulator, external interference is isolated from the shaft core 111 and the bearing 112 by the middle tube 113. Therefore, the shaft voltage caused by external interference on the shaft core 111 or the bearing 112 is also less. Similarly, since the common-mode voltage can also be isolated from the shaft core 111 and the bearing 112 by the middle tube 113, the problem of electro-corrosion caused by the addition of common-mode voltage on the shaft core 111 or the bearing 112 can be avoided.

[0032] In the embodiments of this application, such as Figure 1As shown, the shaft core 111 and bearing 112 are disposed within the central tube 113. The bearing 112 is sleeved on the shaft core 111, meaning the central tube 113 can be a tube with a central opening, and the shaft core 111 is an elongated cylindrical shape. The shaft core 111 can be located within the central tube 113, and the bearing 112 is sleeved on the shaft core 111 and connected to the central tube 113. This allows the central tube 113 and the shaft core 111 to rotate relative to each other via the bearing 112. Furthermore, the coil 114 is sleeved within the central tube 113, and multiple magnetic groups 115 are evenly arranged around the coil 114. When the coil 114 is energized, the magnetic field generated by the coil 114 interacts with the magnetic field of the magnetic groups 115. Under the interaction of the magnetic fields, the coil 114 can rotate relative to the magnetic groups 115. Thus, by controlling the electrical signal connected to the coil 114, the relative rotation of the magnetic groups 115 and the coil 114 can be controlled to achieve the rotational output of the motor 11.

[0033] In some embodiments, the shaft core 111 may be made of one of the following materials: zirconium oxide, aluminum oxide, silicon nitride, or silicon carbide. In this case, using one of the following materials, the shaft core 111 can be formed to be wear-resistant, corrosion-resistant, with a low coefficient of thermal expansion, high temperature resistance, and high insulation. On the one hand, this can improve the service life of the shaft core 111, and on the other hand, it can reduce the problem of bearing 112 being electro-corroded due to shaft voltage.

[0034] In other embodiments, the shaft core 111 may also include one of novel ceramic materials such as boron nitride and boron carbide. That is, the shaft core 111 in the embodiments of this application may also be prepared using one of novel ceramic materials such as boron nitride and boron carbide.

[0035] In some embodiments, the central tube 113 may comprise a material selected from liquid crystal polymer (LCP) or polyphenylene sulfide (PPS). In this case, using either liquid crystal polymer or polyphenylene sulfide can create a heat-resistant, dimensionally stable, and highly insulating central tube 113. This provides stable support for the coil 114, improving its stability. Furthermore, it reduces the conduction of shaft voltage or common-mode voltage caused by electrical signal interference in the coil 114 to the bearing 112, thereby reducing the problem of electrolytic corrosion of the bearing 112.

[0036] In other embodiments, the central tube 113 may also comprise one of a plastic material such as polyetherimide (PEI), polysulfone (PSF), or polyimide (PI). That is, the central tube 113 in the embodiments of this application may be prepared from one of a plastic material such as polyetherimide, polysulfone, or polyimide.

[0037] In some embodiments, such as Figure 1 As shown, the bearing 112 may include a first bearing 1121 and a second bearing 1122, which are respectively sleeved on both ends of the shaft core 111. In this case, when the motor 11 is running, the shaft core 111 and the middle tube 113 are supported by the first bearing 1121 and the second bearing 1122, which can improve the stability of the relative rotation of the shaft core 111 and the middle tube 113.

[0038] In some embodiments, the first bearing 1121 or the second bearing 1122 may be a double ball bearing 112.

[0039] In some embodiments, such as Figure 1 As shown, the motor 11 also includes an elastic element 116, which is sleeved on the shaft core 111 and its two ends are respectively connected to the first bearing 1121 and the second bearing 1122. In this case, the elastic element 116 can maintain a predetermined distance between the first bearing 1121 and the second bearing 1122, and at the same time, the elasticity can reduce the vibration of the first bearing 1121 or the second bearing 1122 during rotation, thereby further improving the stability of the relative rotation of the shaft core 111 and the middle tube 113.

[0040] In some embodiments, the elastic element 116 may include a spring. The spring is sleeved on the shaft core 111 and its two ends are respectively connected to a first bearing 1121 and a second bearing 1122.

[0041] In some embodiments, the elastic element 116 is a conductor. In embodiments of this application, the elastic element 116 can be a metal spring. In this case, the charge of the first bearing 1121 or the second bearing 1122 can be conducted by the elastic element 116, thereby making the potentials of the first bearing 1121 and the second bearing 1122 the same, which can reduce the discharge erosion caused by the potential difference between the first bearing 1121 and the second bearing 1122.

[0042] In some embodiments, such as Figure 1 As shown, the motor 11 also includes an upper housing 117, which has a rotor mounting portion and a magnetic assembly 115 mounting portion. The rotor mounting portion is used to mount the shaft core 111, and the magnetic assembly 115 mounting portion is used to mount the magnetic assembly 115. In this case, the upper housing 117, the shaft core 111, and the magnetic assembly 115 can form a stable whole to maintain stability when operating as the rotor part of the motor 11.

[0043] In some embodiments, such as Figure 1As shown, the motor 11 also includes a lower housing 118, which has a stator mounting portion for mounting the intermediate tube 113. In this case, the lower housing 118, the intermediate tube 113, and the coil 114 can form a stable whole to maintain stability when operating as the stator part of the motor 11.

[0044] In some embodiments, such as Figure 1 As shown, the motor 11 also includes a circuit assembly 119, which is sleeved on the stator mounting portion and electrically connected to the coil 114. In this case, the circuit assembly 119 can apply an electrical signal to the coil 114 to control the magnetic field of the coil 114, thereby controlling the operation of the motor 11.

[0045] In the embodiments of this application, the upper housing 117 and the lower housing 118 can cooperate to form a cavity that accommodates the shaft core 111, bearing 112, middle tube 113, coil 114, magnetic assembly 115 and circuit assembly 119, thereby protecting the shaft core 111, bearing 112, middle tube 113, coil 114, magnetic assembly 115 and circuit assembly 119.

[0046] In some embodiments, the upper housing 117 and the lower housing 118 may be made of a high-temperature resistant material.

[0047] In some embodiments, the upper housing 117 can be used to mount the fan blades 12 for heat dissipation in high-temperature operating environments.

[0048] In some embodiments, coil 114 may include a plastic-coated coil winding.

[0049] In some embodiments, the magnetic assembly 115 may include at least one of a permanent magnet or an excitation magnet.

[0050] Figure 2 This is a schematic diagram of the structure of the cooling fan 1 according to an embodiment of this application.

[0051] Please see Figure 2 The embodiments of this application also provide a cooling fan 1, including the motor 11 in any of the above embodiments of this application. The cooling fan 1 can be used for heat dissipation in high-temperature environments.

[0052] In some embodiments, such as Figure 2 As shown, the cooling fan 1 may also include fan blades 12. The upper housing 117 of the motor 11 can be used to mount the fan blades 12.

[0053] In some embodiments, such as Figure 2As shown, the cooling fan 1 may also include an outer frame 13, and the lower housing 118 of the motor 11 may be connected to the outer frame 13. Thus, the lower housing 118 can be stably fixed to the outer frame 13, while the upper housing 117 and the fan blades 12 can rotate relative to the lower housing 118.

[0054] In the cooling fan 1 of this application, since the shaft core 111 of the motor 11 is an insulator, even if there is an imbalance in the magnetic field when the motor 11 is running, the shaft core 111 will not generate shaft voltage, nor will it be conducted to the bearing 112, thereby reducing the problem of electrolytic corrosion of the bearing 112. Furthermore, since the shaft core 111 of the motor 11 is an insulator, the generation of shaft voltage caused by static electricity generated by friction between the shaft core 111 and the bearing 112 or air during motor operation is reduced. Additionally, since the middle tube 113 of the motor 11 is also an insulator, the conduction of shaft voltage and common-mode voltage generated by external interference to the bearing 112 is reduced. Furthermore, the first bearing 1121 and the second bearing 1122 of the motor 11 are connected by an elastic element 116, and the elastic element 116 is a conductor. In this case, the charge of the first bearing 1121 or the second bearing 1122 can be conducted by the elastic element 116, thereby making the potentials of the first bearing 1121 and the second bearing 1122 the same, which can reduce the discharge corrosion caused by the potential difference between the first bearing 1121 and the second bearing 1122. Thus, the problem of electro-corrosion of bearing 112 can be reduced by this application.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. An electric motor characterized by, The motor comprises a shaft core, a bearing, a middle tube, a coil and a plurality of magnetic groups, the shaft core and the bearing are arranged in the middle tube, the bearing is sleeved on the shaft core, the coil is sleeved on the middle tube, the plurality of magnetic groups are arranged around the coil, and the shaft core and the middle tube are both insulators.

2. The electric motor of claim 1, wherein The bearing comprises a first bearing and a second bearing, and the first bearing and the second bearing are respectively sleeved on two ends of the shaft core.

3. The electric motor of claim 2, wherein, The motor further comprises an elastic member, the elastic member is sleeved on the shaft core, and two ends of the elastic member are respectively connected to the first bearing and the second bearing.

4. The electric motor of claim 3, wherein The elastic member is a conductive body.

5. The electric motor of claim 1, wherein The shaft core comprises one of zirconia, alumina, silicon nitride or silicon carbide.

6. The electric motor of claim 1, wherein The middle tube comprises one of liquid crystal polymer or polyphenylene sulfide.

7. The electric motor of claim 1, wherein The motor further comprises an upper housing, the upper housing is formed with a rotor mounting portion and a magnetic group mounting portion, the rotor mounting portion is used for mounting the shaft core, and the magnetic group mounting portion is used for mounting the magnetic groups.

8. The electric motor of claim 1, wherein The motor further comprises a lower housing, the lower housing is formed with a stator mounting portion, and the stator mounting portion is used for mounting the middle tube.

9. The electric motor of claim 8, wherein, The motor further comprises a circuit assembly, the circuit assembly is sleeved on the stator mounting portion, and the circuit assembly is electrically connected to the coil.

10. A heat dissipating fan characterized by comprising: The motor comprises any one of the motors according to claims 1 to 9.

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