Electric machines and electric appliances

Abstract

The utility model discloses a motor and electrical equipment, and the motor includes: stator subassembly, stator subassembly includes stator core, rotor subassembly, rotor subassembly includes rotor main body and is worn in rotor main body's rotor shaft, two bearing seats, two bearing seats are arranged respectively in rotor main body's axial both sides, and rotor shaft passes through two bearings and is supported and is installed in two bearing seats, and bearing includes inner ring and outer ring, and inner ring is connected with rotor shaft electricity, and outer ring is connected with bearing seat electricity, capacitor, capacitor, stator core and one of bearing seat series connection, and two bearing seats pass through first conducting part electricity and are connected, so that capacitor, stator core and two bearing seats form equivalent capacitance. According to the utility model embodiment's motor balances the inner ring and outer ring of bearing, effectively reduces the voltage difference of bearing inner ring and outer ring, improves the problem of bearing electric corrosion, is favorable for reducing bearing noise.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and more specifically, to a motor and electrical equipment. Background Technology

[0002] In motors using pulse width modulation (PWM) variable frequency speed control, the common-mode voltage is divided and distributed across the inner and outer rings of the bearing due to the coupling effect of the distributed capacitance inside the motor, creating a voltage difference. A high voltage difference can cause the oil film of the bearing grease to break down and be destroyed, damaging the bearing metal surface and generating severe bearing noise. Utility Model Content

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a motor that improves the problem of bearing electro-corrosion and helps to reduce bearing noise.

[0004] Another objective of this invention is to provide an electrical device having the aforementioned motor.

[0005] An electric motor according to an embodiment of the present invention includes: a stator assembly, the stator assembly including a stator core; a rotor assembly, the rotor assembly including a rotor body and a rotor shaft passing through the rotor body; two bearing seats, the two bearing seats respectively disposed on both axial sides of the rotor body, the rotor shaft being supported and mounted on the two bearing seats by two bearings respectively, each bearing including an inner ring and an outer ring, the inner ring being electrically connected to the rotor shaft, and the outer ring being electrically connected to the bearing seat; and a capacitor, the capacitor, the stator core and one of the bearing seats being connected in series, the two bearing seats being electrically connected by a first conductive element, so that the capacitor, the stator core and the two bearing seats form an equivalent capacitance.

[0006] According to the embodiment of the present invention, the motor connects a capacitor, a stator core, and one of the bearing housings in series, and the two bearing housings are electrically connected through a first conductive element. This balances the voltage distribution between the inner and outer rings of the bearing, effectively reduces the voltage difference between the inner and outer rings, improves the problem of bearing electro-corrosion, and helps reduce bearing noise.

[0007] In addition, the motor according to the above embodiments of this utility model may also have the following additional technical features:

[0008] According to some embodiments of the present invention, the motor has a capacitor located on one axial side of the stator assembly. The motor also includes a pin, one end of which is electrically connected to the capacitor, and the other end of which is inserted into the stator core for electrical connection with the stator core.

[0009] According to some embodiments of the present invention, one of the bearing seats is a first bearing seat, the first bearing seat and the stator assembly cooperate to form a receiving cavity, the capacitor is located in the receiving cavity and is electrically connected to the first bearing seat through a second conductive element.

[0010] According to some embodiments of the present invention, the stator assembly includes an insulator, the insulator includes an insulating body and a first mating part, the stator core is mounted on the insulating body, the first mating part is disposed at one axial end of the insulating body and mates with the first bearing seat, the insulating body and the first bearing seat form the receiving cavity, the first mating part is located radially outside the receiving cavity, the first mating part is provided with a through hole, the second conductive element passes through the through hole, and the portion of the second conductive element outside the receiving cavity is electrically connected to the first bearing seat.

[0011] According to some embodiments of the present invention, the through hole is also used to bring out the leads of the winding of the stator assembly.

[0012] According to some embodiments of the present invention, the capacitance value of the capacitor is less than or equal to 30pF.

[0013] According to some embodiments of the present invention, the stator assembly includes an insulator, the insulator includes an insulating body, a first mating part and a second mating part, the first mating part and the second mating part are respectively disposed at both ends of the insulating body, the two bearing seats are a first bearing seat and a second bearing seat, wherein the first end of the first conductive element is sandwiched between the first bearing seat and the first mating part, and the second end of the first conductive element is connected to the second bearing seat and the second mating part by fasteners.

[0014] According to some embodiments of the present invention, a hook is formed at the first end of the first conductive member, the hook is disposed at the end of the first mating part away from the insulating body, and the first bearing seat abuts against the end face of the hook facing away from the first mating part.

[0015] According to some embodiments of the present invention, the second bearing housing includes an outer extension extending radially away from the bearing, the second mating portion includes an inner extension extending radially, and the second end of the first conductive element, the inner extension, and the outer extension are arranged in an axially stacked manner and connected by fasteners.

[0016] The electrical equipment according to an embodiment of the present invention includes a motor according to an embodiment of the present invention.

[0017] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of a motor according to an embodiment of the present utility model.

[0020] Figure label:

[0021] Motor 100;

[0022] Stator assembly 10; stator core 11; insulator 12; insulation body 121; first mating part 122; second mating part 123; inner extension 124; winding 13; lead wire 131;

[0023] Rotor assembly 20; Rotor body 21; Rotor shaft 22;

[0024] Bearing housing 30; First bearing housing 31; Receiving cavity 311; Second bearing housing 32; Extension section 321;

[0025] Bearing 40; Inner ring 41; Outer ring 42;

[0026] Capacitor 50;

[0027] First conductive element 61; first end 611; second end 612; second conductive element 62; pin 63;

[0028] Fastener 70. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0030] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0031] In the description of this utility model, "first feature" and "second feature" may include one or more of the features, "multiple" means two or more, "first feature above" or "below" the second feature may include the first and second features being in direct contact, or the first and second features being in contact through another feature between them, and "first feature above", "above" and "over" the second feature may include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0032] The motor 100 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0033] Reference Figure 1 As shown, the motor 100 according to an embodiment of the present invention may include: a stator assembly 10, a rotor assembly 20, two bearing seats 30 and a capacitor 50.

[0034] Specifically, the stator assembly 10 includes a stator core 11; the rotor assembly 20 includes a rotor body 21 and a rotor shaft 22 passing through the rotor body 21. For example, the rotor body 21 may include a rotor core, permanent magnets, etc. Figure 1 As shown, the stator assembly 10 may have a receiving cavity, the rotor body 21 is located in the receiving cavity of the stator assembly 10, and the rotor shaft 22 passes through the stator assembly 10.

[0035] Two bearing housings 30 are respectively located on both axial sides of the rotor body 21, and the rotor shaft 22 is supported and mounted on the two bearing housings 30 by two bearings 40 respectively. This allows the bearing housings 30 to provide support for the bearings 40, and the bearings 40 to provide support for the rotation of the rotor shaft 22.

[0036] The bearing 40 includes an inner ring 41 and an outer ring 42. For example, there may be balls between the inner ring 41 and the outer ring 42, allowing the inner ring 41 and the outer ring 42 of the bearing 40 to rotate freely. In addition, the inner ring 41 is electrically connected to the rotor shaft 22, and the outer ring 42 is electrically connected to the bearing housing 30, so that the inner ring 41 and the rotor shaft 22 are at the same potential, and the outer ring 42 and the bearing housing 30 are at the same potential.

[0037] A large difference in capacitance between the equivalent capacitance on the stator side and the equivalent capacitance on the rotor side can lead to a large voltage difference between the inner and outer rings of the bearing, i.e., excessive shaft voltage, thereby increasing the risk of electro-corrosion of the bearing.

[0038] Therefore, in this application, capacitor 50, stator core 11, and one of the bearing housings 30 are connected in series, and the two bearing housings 30 are electrically connected through a first conductive element 61, so that capacitor 50, stator core 11, and the two bearing housings 30 form an equivalent capacitance. That is, stator core 11 and bearing housing 30 are connected through capacitor 50, and the two bearing housings 30 are connected together. Adjusting the capacitance of the outer ring 42 of bearing 40, i.e., adjusting the equivalent capacitance on the stator side, balances the voltage division between the inner ring 41 and outer ring 42 of bearing 40, reduces the voltage difference between the inner ring 41 and outer ring 42 of bearing 40, and thus improves the electro-corrosion problem of bearing 40.

[0039] Furthermore, the voltage difference between the inner and outer rings of the comparative example and the embodiment of this application was measured using a voltage detector. Specifically, the difference between the comparative example and the embodiment of this application is that the capacitor 50 and the first conductive element 61 are not provided, and the stator core 11 and the bearing housing 30 are not connected in series. During the testing process, the two test heads of the voltage detector were connected to the rotor shaft 22 and the bearing housing 30 respectively, and three sets of data were obtained. Among them, the three sets of voltage differences obtained by the comparative example were 11.975V, 12.95V, and 12.538V, respectively, while the three sets of voltage differences obtained by the embodiment of this application were 2.544V, 2.069V, and 2.181V, respectively. The comparison shows that the motor 100 of the embodiment of this application effectively reduces the voltage difference between the inner ring 41 and the outer ring 42 of the bearing 40.

[0040] According to the embodiment of this application, the motor 100 connects the capacitor 50, the stator core 11 and one of the bearing housings 30 in series, and the two bearing housings 30 are electrically connected through the first conductive element 61. This balances the voltage distribution between the inner ring 41 and the outer ring 42 of the bearing 40, effectively reduces the voltage difference between the inner ring 41 and the outer ring 42 of the bearing 40, improves the problem of electrical corrosion of the bearing 40, and helps to reduce the noise of the bearing 40.

[0041] In the embodiments of this application, the capacitance value of capacitor 50 can be selected according to different motors 100 (e.g., motors 100 with different power). In some embodiments of this utility model, the capacitance value of capacitor 50 is less than or equal to 30pF. An excessively large capacitance value of capacitor 50 can easily lead to leakage current. Within the above-mentioned value range, the capacitance value of capacitor 50 is more reasonable, less prone to current leakage, and meets regulatory requirements. For example, the capacitance value of capacitor 50 can be 30pF, 25pF, 20pF, 15pF, 10pF, 5pF, etc.

[0042] According to some embodiments of this utility model, such as Figure 1 As shown, capacitor 50 is located on one axial side of stator assembly 10. Motor 100 also includes pin 63, one end of which is electrically connected to capacitor 50, and the other end of which is inserted into stator core 11 for electrical connection with stator core 11.

[0043] The pin 63 not only enables electrical connection between capacitor 50 and stator core 11, but also provides support for capacitor 50, enabling its installation. This simplifies the structure by eliminating the need for a separate mounting structure for capacitor 50. However, depending on actual needs, capacitor 50 can also be installed using a different mounting structure to improve installation reliability.

[0044] During the assembly process, a socket can be provided on the stator assembly 10. After the stator core 11, winding 13, insulator 12 and other components of the stator assembly 10 are assembled, the pin 63 is inserted into the socket to achieve mechanical and electrical connection with the stator core 11.

[0045] In some embodiments of this utility model, such as Figure 1 As shown, one of the two bearing housings 30 is the first bearing housing 31, which mates with the stator assembly 10 to form a receiving cavity 311. The capacitor 50 is located within the receiving cavity 311 and is electrically connected to the first bearing housing 31 via a second conductive element 62.

[0046] The capacitor 50 can make full use of the space between the first bearing housing 31 and the stator assembly 10, making the structure compact. The first bearing housing 31 and the stator assembly 10 can provide shielding and protection for the capacitor 50. For example, the stator assembly 10 has an end opening at one axial end, through which the rotor assembly 20 can be mounted. The first bearing housing 31 can be formed as an end cap, which is located on one axial side of the stator assembly 10 and covers the end opening. The outer periphery of the end cap is connected to the stator assembly 10 so that the end cap and the stator assembly 10 cooperate to define a receiving cavity 311.

[0047] It should be noted that the second conductive component 62 can be any conductive component such as a wire or a metal sheet.

[0048] In some embodiments, continue to refer to Figure 1 As shown, the stator assembly 10 includes an insulator 12, which includes an insulating body 121 and a first mating portion 122. The stator core 11 is mounted on the insulating body 121, and the first mating portion 122 is located at one axial end of the insulating body 121 and mates with a first bearing housing 31. A receiving cavity 311 is formed between the insulating body 121 and the first bearing housing 31, and the first mating portion 122 is located radially outside the receiving cavity 311.

[0049] The first mating part 122 can be used to connect the stator assembly 10 and the first bearing housing 31, and the first mating part 122 can form a gap between the insulating body 121 and the first bearing housing 31 to facilitate the formation of the receiving cavity 311, which is convenient for arranging components such as the capacitor 50.

[0050] In some specific embodiments, the insulator 12 can be an injection molded body, formed by injection molding. Injection molding not only produces the insulator 12 but also simultaneously connects the insulator 12 to components such as the stator core 11 and windings 13, improving insulation and corrosion resistance. The insulator 12 can be integrally injection molded or formed through multiple injection molding processes, all of which are within the protection scope of this utility model.

[0051] Furthermore, the first mating part 122 is provided with a through hole, through which the second conductive element 62 passes, and the portion of the second conductive element 62 located outside the receiving cavity 311 is electrically connected to the first bearing housing 31. Therefore, the connection operation between the second conductive element 62 and the first bearing housing 31 can be performed from the outside of the first bearing housing 31, making the operation more convenient. During assembly, the first bearing housing 31 can be assembled with the stator assembly 10 first, and then the second conductive element 62 can be connected to the first bearing housing 31, ensuring that the second conductive element 62 and its connection structure with the first bearing housing 31 do not interfere with the assembly of the first bearing housing 31 and the stator assembly 10.

[0052] For example Figure 1 As shown, the first bearing housing 31 is provided with a mounting hole, and the fastener 70 passes through the part of the second conductive element 62 located outside the receiving cavity 311 and the mounting hole, so as to realize the mechanical connection and electrical connection between the second conductive element 62 and the first bearing housing 31.

[0053] In some embodiments, the through hole is also used to bring out the lead 131 of the winding 13 of the stator assembly 10. In other words, the lead 131 of the winding 13 and the second conductive element 62 are brought out through the same hole; in other words, the second conductive element 62 can be arranged using the through hole on the insulator 12 for bringing out the lead 131 without the need for additional holes, which helps to simplify the structure of the first mating part 122 and reduce production costs.

[0054] According to some embodiments of this utility model, such as Figure 1 As shown, the stator assembly 10 includes an insulator 12, which includes an insulating body 121, a first mating portion 122, and a second mating portion 123. The first mating portion 122 and the second mating portion 123 are respectively disposed at both axial ends of the insulating body 121. The two bearing seats 30 are a first bearing seat 31 and a second bearing seat 32. The first end 611 of the first conductive element 61 is sandwiched between the first bearing seat 31 and the first mating portion 122, and the second end 612 of the first conductive element 61 is connected to the second bearing seat 32 and the second mating portion 123 via fasteners 70.

[0055] During assembly, the first end 611 of the first conductive element 61 can be clamped between the first bearing seat 31 and the first mating part 122, and then the second end 612 of the first conductive element 61 and the second mating part 123 can be connected by fastener 70. Alternatively, the second end 612 of the first conductive element 61 and the second mating part 123 can be connected by fastener 70 first, and then the first end 611 of the first conductive element 61 can be clamped between the first bearing seat 31 and the first mating part 122.

[0056] The two ends of the first conductive element 61 adopt different connection methods. On the one hand, it is easy to accommodate machining and assembly errors. For example, it is not necessary to set mounting holes for fasteners 70 at both ends, avoiding the difficulty or even inability to install due to errors in the machining position of the mounting holes. On the other hand, the clamping installation method is conducive to improving the installation efficiency of the first end 611 of the first conductive element 61, thereby improving the overall installation efficiency.

[0057] In some embodiments, continue to refer to Figure 1 As shown, the first end 611 of the first conductive member 61 forms a hook, which is attached to the end of the first mating part 122 away from the insulating body 121, and the first bearing seat 31 abuts against the end face of the hook facing away from the first mating part 122.

[0058] During the assembly process, the hook can be first set on the first mating part 122 to achieve initial fixation. Then, the first bearing seat 31 is assembled with the stator assembly 10 and abuts against the hook to achieve further fixation. This improves the connection reliability of the first end 611 of the first conductive element 61 and the stability of the electrical connection. The hook ensures that the first end 611 of the first conductive element 61 is firmly and reliably positioned in the axial, radial and circumferential directions. Furthermore, during the assembly of the first bearing seat 31 and the stator assembly 10, the first conductive element 61 and the first mating part 122 are not easily loosened, which would affect the assembly.

[0059] In some specific embodiments, the main body of the first conductive element 61 can extend axially along the outer peripheral surface of the stator assembly 10, so that the first end 611 and the second end 612 can respectively cooperate with the first bearing seat 31 and the second bearing seat 32, and the first conductive element 61 and the stator assembly 10 are less likely to interfere.

[0060] In some embodiments, continue to refer to Figure 1 As shown, the second bearing housing 32 includes an outer extension 321 extending radially away from the bearing 40, and the second mating part 123 includes an inner extension 124 extending radially. The second end 612 of the first conductive element 61, the inner extension 124 and the outer extension 321 are stacked axially and connected by fasteners 70.

[0061] By stacking the second end 612, inner extension 124, and outer extension 321 axially, the first conductive element 61, the second bearing housing 32, and the stator assembly 10 can be axially limited. Furthermore, by connecting the three components with fasteners 70, axial, radial, and circumferential fixation can be achieved, improving the reliability of the connection and the stability of the electrical connection. Moreover, the fasteners 70 can be assembled from one axial side of the stator assembly 10, providing ample operating space and reducing operational difficulty.

[0062] In some specific embodiments, the second bearing housing 32 and the second mating part 123 can be connected by injection molding. That is, the connection with the second bearing housing 32 is realized during the injection molding process of the second mating part 123, which eliminates the assembly process, improves production efficiency, and improves the connection reliability between the second bearing housing 32 and the stator assembly 10.

[0063] The electrical device according to an embodiment of the present invention includes a motor 100 according to an embodiment of the present invention. Since the motor 100 according to the present invention has the aforementioned beneficial technical effects, the electrical device according to the present invention balances the voltage distribution between the inner ring 41 and the outer ring 42 of the bearing 40, effectively reducing the voltage difference between the inner ring 41 and the outer ring 42 of the bearing 40, improving the problem of electro-corrosion of the bearing 40, and helping to reduce the noise of the bearing 40.

[0064] In the above embodiments, the electrical equipment may be, but is not limited to, an air conditioner, etc.

[0065] Other components and operations of the motor 100 and electrical equipment according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0066] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0067] In the description of this specification, the references to terms such as "embodiment," "specific embodiment," and "example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0068] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An electric machine characterized in that, include: A stator assembly, the stator assembly including a stator core; A rotor assembly, the rotor assembly including a rotor body and a rotor shaft passing through the rotor body; Two bearing housings are respectively disposed on both axial sides of the rotor body. The rotor shaft is supported and mounted on the two bearing housings by the two bearings respectively. Each bearing includes an inner ring and an outer ring. The inner ring is electrically connected to the rotor shaft, and the outer ring is electrically connected to the bearing housing. A capacitor, the stator core and one of the bearing housings are connected in series, and the two bearing housings are electrically connected through a first conductive element, so that the capacitor, the stator core and the two bearing housings form an equivalent capacitance.

2. The electric machine of claim 1, wherein, The capacitor is located on one axial side of the stator assembly. The motor also includes a pin, one end of which is electrically connected to the capacitor, and the other end of which is inserted into the stator core for electrical connection with the stator core.

3. The electric machine of claim 1, wherein, One of the bearing housings is a first bearing housing, which is fitted with the stator assembly to form a receiving cavity. The capacitor is located in the receiving cavity and is electrically connected to the first bearing housing through a second conductive element.

4. The motor according to claim 3, characterized in that, The stator assembly includes an insulator, which comprises an insulating body and a first mating portion. The stator core is mounted on the insulating body. The first mating portion is located at one axial end of the insulating body and mates with a first bearing seat. A receiving cavity is formed between the insulating body and the first bearing seat. The first mating portion is located radially outside the receiving cavity. The first mating part is provided with a through hole, the second conductive element passes through the through hole, and the part of the second conductive element located outside the receiving cavity is electrically connected to the first bearing seat.

5. The motor according to claim 4, characterized in that, The through hole is also used to bring out the leads of the windings of the stator assembly.

6. The motor according to claim 1, characterized in that, The capacitance of the capacitor is less than or equal to 30pF.

7. The motor according to any one of claims 1-6, characterized in that, The stator assembly includes an insulator, which comprises an insulating body, a first mating portion, and a second mating portion. The first mating portion and the second mating portion are respectively disposed at both axial ends of the insulating body. The two bearing seats are a first bearing seat and a second bearing seat. The first end of the first conductive element is sandwiched between the first bearing seat and the first mating part, and the second end of the first conductive element is connected to the second bearing seat and the second mating part by fasteners.

8. The motor according to claim 7, characterized in that, The first end of the first conductive element forms a hook, which is hooked to the end of the first mating part away from the insulating body, and the first bearing seat abuts against the end face of the hook facing away from the first mating part.

9. The motor according to claim 7, characterized in that, The second bearing housing includes an outer extension extending radially away from the bearing, and the second mating portion includes an inner extension extending radially. The second end of the first conductive element, the inner extension, and the outer extension are arranged axially stacked and connected by fasteners.

10. An electrical appliance, characterized in that, Includes the motor according to any one of claims 1-9.

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