Stator structure and motor having it

Abstract

This application provides a stator structure and a motor having the same, including a stator core, an end cover, and a connecting structure. The end cover is a conductor and is disposed at one end of the stator core. The connecting structure further includes an annular structure, which is sleeved on the outside of the stator core and electrically connected to the stator core. The connecting structure is electrically connected to the end cover. And / or, the connecting structure can be electrically connected to a support structure, which is used to support the structure to be installed. This application can reduce shaft voltage to improve the safety of the motor.

Description

Technical Field

[0001] This application relates to the field of motor technology, specifically to a stator structure and a motor having the same. Background Technology

[0002] Currently, the development of permanent magnet brushless DC motors needs to balance high performance and low cost; however, safety is the most important design indicator for a motor.

[0003] However, motor damage during long-term operation is a common phenomenon, with numerous causes, which has brought considerable negative impact to the market. One safety hazard is the shaft current breakdown caused by high shaft voltage, leading to corrosion of the bearing outer ring. The main sources of excessive shaft voltage leading to shaft current breakdown of the oil film are: 1. Imbalance in the motor's internal magnetic circuit, resulting in alternating magnetic flux with harmonics linked to the shaft, creating a large potential difference; 2. The presence of common-mode voltage and parasitic coupling capacitance in the inverter generates high-frequency discharge shaft current at the bearing, damaging it.

[0004] Therefore, how to provide a stator structure that can reduce shaft voltage to improve motor safety, and a motor having the same structure, has become an urgent problem for those skilled in the art. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this application is to provide a stator structure and a motor having the same, which can reduce shaft voltage to improve motor safety.

[0006] To address the aforementioned problems, this application provides a stator structure, comprising:

[0007] Stator core;

[0008] End cap, the end cap is a conductor, and the end cap is set at one end of the stator core;

[0009] The connection structure further includes a ring structure, which is sleeved on the outside of the stator core and electrically connected to the stator core; the connection structure is electrically connected to the end cover; and / or, the connection structure can be electrically connected to a support structure, which is used to support the structure to be installed.

[0010] Furthermore, when the connecting structure is electrically connected to the supporting structure, a connecting hole is provided on the connecting structure; the fastening structure can pass through the connecting hole to fasten the connecting structure to the supporting structure, thereby making the connecting structure electrically connected to the supporting structure.

[0011] Furthermore, the connecting structure includes a connector disposed on the outer periphery of the annular structure; a connecting hole is disposed on the connector.

[0012] Furthermore, when the connecting structure is electrically connected to the end cover, the connecting structure includes an axial extension portion, which is connected to the annular structure and extends in the direction of the central axis of the annular structure; the axial extension portion extends to one end of the stator core so that the axial extension portion contacts the end cover, thereby making the axial extension portion electrically connected to the end cover.

[0013] Furthermore, a second clearance groove is provided on the outer surface of the stator core, and the axial extension is disposed in the second clearance groove.

[0014] Furthermore, a first clearance groove is provided on the outer surface of the stator core, and an annular structure is disposed within the first clearance groove.

[0015] Furthermore, the stator core is made of lamination assemblies; the lamination assemblies include a first lamination group, a second lamination group, and a third lamination group; the first lamination group includes at least one first lamination; the second lamination group includes at least one second lamination; the third lamination group includes at least one third lamination; the first lamination group, the second lamination group, and the third lamination group are stacked sequentially; the outer diameter of the second lamination is smaller than the outer diameter of the first lamination; the outer diameter of the second lamination is smaller than the outer diameter of the third lamination; when a first clearance groove is provided on the outer surface of the stator core, the first clearance groove is formed on the outer periphery of the second lamination group.

[0016] Furthermore, when a second clearance groove is provided on the outer surface of the stator core, a groove is provided on the outer periphery of the third lamination group, and the groove forms the second clearance groove.

[0017] Furthermore, the stator structure also includes a plastic-coated structure; the stator core, connecting structure, and end cap are encapsulated into a single unit through the plastic-coated structure.

[0018] According to another aspect of this application, an electric motor is provided, including a stator structure, the stator structure being the stator structure described above.

[0019] This application provides a stator structure and a motor having the same. This application can reduce shaft voltage, thereby improving the safety of the motor. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the motor structure in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the stator structure in an embodiment of this application;

[0022] Figure 3 This is a top view of the stator structure in an embodiment of this application;

[0023] Figure 4 This is a schematic diagram of the stator structure in an embodiment of this application;

[0024] Figure 5 This is a schematic diagram of the stator structure in an embodiment of this application;

[0025] Figure 6 This is a schematic diagram of the stator structure in an embodiment of this application;

[0026] Figure 7 This is a schematic diagram of the operation process of the stator structure in the embodiments of this application;

[0027] Figure 8 This is a schematic diagram of the operation process of the stator structure in the embodiments of this application;

[0028] Figure 9 This is a schematic diagram of the connection structure in an embodiment of this application;

[0029] Figure 10 This is a schematic diagram of the connection structure in an embodiment of this application;

[0030] Figure 11 This is a schematic diagram of the stator core structure in the embodiments of this application;

[0031] Figure 12 This is a schematic diagram of the structure of the first lamination in the embodiment of this application;

[0032] Figure 13 This is a schematic diagram of the structure of the second lamination in an embodiment of this application;

[0033] Figure 14 This is a schematic diagram of the structure of the third lamination in the embodiments of this application;

[0034] Figure 15 This is a schematic diagram illustrating the working principle of the motor in the embodiments of this application;

[0035] Figure 16 This is a circuit diagram of the motor in an embodiment of this application;

[0036] Figure 17 This is a circuit diagram of a motor in related technologies.

[0037] 1. Stator core; 11. First lamination group; 111. First lamination; 12. Second lamination group; 121. Second lamination; 13. Third lamination group; 131. Third lamination; 2. End cover; 3. Connecting structure; 31. Ring structure; 32. Connector; 321. Connecting hole; 33. Axial extension; 4. Plastic-coated structure; 5. Bearing; 6. Shaft; 7. Rotor; 8. Cover; 91. Stator winding; 92. Permanent magnet. Detailed Implementation

[0038] See also Figure 1-17As shown in the diagram, a stator structure includes a stator core 1, an end cap 2, and a connecting structure 3. The end cap 2 is a conductor and is disposed at one end of the stator core 1. The connecting structure 3 further includes an annular structure 31, which is sleeved on the outside of the stator core 1 and electrically connected to the stator core 1. The connecting structure 3 is electrically connected to the end cap 2. And / or, the connecting structure 3 can be electrically connected to a support structure, which is used to support the structure to be installed.

[0039] In this application, the connecting structure 3 connects the end cap 2 to the stator core 1 and / or the support structure, which is equivalent to connecting a small resistor in parallel across the capacitor on the bearing side. This reduces the voltage distribution across the bearing and lowers the shaft voltage. The support structure can be a load mounting bracket for mounting an air conditioner. The support structure is made of conductive material. The support structure is made of metal. This application effectively reduces the voltage distribution across the bearing and lowers the shaft voltage by employing the principle of parallel impedance reduction, thereby improving safety. The ring assembly can be fastened by welding to the stator core 1, interference fit, threaded fastening, etc.

[0040] Based on the parasitic coupling capacitance circuit generated by the common-mode voltage, such as Figure 15 The capacitance values ​​for the plastic-coated structure are shown below.

[0041] In related technologies, without the addition of connection structure 3, the circuit is as follows: Figure 17 As shown in the diagram, the impedance corresponding to the distribution voltage of the shaft voltage Vb is 1 / (JCrf+JCb1+JCb2), where Crf is the capacitance between the stator and rotor cores, and Cb1 and Cb2 are the bearing capacitances.

[0042] After connection structure 3 in this application, the circuit diagram is as follows: Figure 17 As shown in the diagram, the impedance corresponding to the distribution voltage Vb of the shaft voltage is 1 / (JCrf+JCb1+JCb2+1 / R), where R is the resistance of the parallel load mounting bracket. The shaft voltage is reduced to (JCrf+JCb1+JCb2) / (JCrf+JCb1+JCb2+1 / R) times its original value. The distribution of the shaft voltage is also reduced accordingly. Here, Cwf is the capacitance between the winding and stator core 1; Cmf is the capacitance between stator core 1 and the permanent magnet; Cwm is the capacitance between the winding and the permanent magnet; Cwr is the capacitance between the winding and the rotor core; Cmr is the capacitance between the permanent magnet and the rotor core; Crf is the capacitance between stator core 1 and the rotor core; Cb is the bearing capacitance; Vb is the shaft voltage; and Vcom is the common-mode voltage. Furthermore, R decreases as the contact area of ​​the load mounting bracket increases; that is, the larger the contact area, the smaller the parallel resistance, and the more significant the voltage reduction.

[0043] The stator assembly of this application consists of a stator structure, a BB cover (cover body 8), and a plastic encapsulating material BMC; the stator structure consists of a stator core 1, a plastic-coated frame, a connecting structure 3, and a stator winding 91, etc. The stator core 1 is composed of three different types of laminations; the connecting structure 3 electrically connects the end cover 2, the stator core 1, and the support structure, which can effectively reduce the bearing side impedance, reduce the voltage drop, and reduce the shaft voltage.

[0044] This application also discloses some embodiments in which, when the connecting structure 3 is electrically connected to the supporting structure, a connecting hole is provided on the connecting structure 3; a fastening structure can pass through the connecting hole to fasten the connecting structure 3 to the supporting structure, thereby making the connecting structure 3 electrically connected to the supporting structure. For example, screws or bolts are used to pass through the connecting hole to connect the connecting structure 3 to the supporting structure, so that the supporting structure and the connecting structure 3 are in tight contact, forming an effective electrical connection.

[0045] This application also discloses some embodiments in which the connecting structure 3 includes a connector 32 disposed on the outer periphery of the annular structure 31; a connecting hole 321 is disposed on the connector 32. The connector 32 is integrally connected to the annular structure 31. The connector 32 extends out of the plastic-coated structure 4.

[0046] This application also discloses some embodiments in which, when the connecting structure 3 is electrically connected to the end cover 2, the connecting structure 3 includes an axial extension 33, which is connected to the annular structure 31 and extends along the central axis of the annular structure 31; the axial extension 33 extends to one end of the stator core 1 so that the axial extension 33 contacts the end cover 2, thereby making the axial extension 33 electrically connected to the end cover 2. The axial extension 33 is a strip structure that extends from the annular structure 31 to the position of the end cover 2 to contact the end cover 2.

[0047] This application also discloses some embodiments in which a second clearance groove is provided on the outer surface of the stator core 1, and the axial extension 33 is disposed in the second clearance groove. This allows the axial extension 33 to be embedded in the stator core 1, so that the axial extension 33 is firmly connected to the stator core 1, which can ensure the stability of the motor during operation, and the outer periphery of the axial extension 33 is injection molded with injection molding material.

[0048] This application also discloses some embodiments in which a first clearance groove is provided on the outer surface of the stator core 1, and an annular structure 31 is disposed in the first clearance groove. The annular structure 31 can be embedded in the stator core 1, thereby making the stator core 1 and the annular structure 31 tightly connected.

[0049] This application also discloses some embodiments in which the stator core 1 is made of lamination assemblies; the lamination assemblies include a first lamination group 111, a second lamination group 121, and a third lamination group 131; the first lamination group 111 includes at least one first lamination 111; the second lamination group 121 includes at least one second lamination 121; the third lamination group 131 includes at least one third lamination 131; the first lamination group 111, the second lamination group 121, and the third lamination group 131 are stacked sequentially; the outer diameter of the second lamination 121 is smaller than the outer diameter of the first lamination 111; the outer diameter of the second lamination 121 is smaller than the outer diameter of the third lamination 131; when a first clearance groove is provided on the outer surface of the stator core 1, the outer periphery of the second lamination group 121 forms the first clearance groove. The stator core 1 is composed of three different core lamination structures to adapt to the annular connection assembly to realize the connection between the end cover 2, the core, and the load support.

[0050] This application also discloses some embodiments in which a second clearance groove is provided on the outer surface of the stator core 1, and a groove is provided on the outer periphery of the third lamination group 131 13, forming the second clearance groove. The groove is an axially extending strip groove, and the shape and size of the groove are adapted to the axial extension portion 33.

[0051] The first lamination 111 is a conventional lamination with no special function, such as an outer diameter of X (mm); the second lamination 121 is a small outer diameter structure, that is, the outer diameter of the second lamination 121 is smaller than the outer diameter of the first lamination; for example, the outer diameter of the second lamination 121 is X-2 (mm), which is smaller than the outer diameter of the first lamination 111 so as to form a first relief groove that fits the annular structure 31, so that the annular structure 31 can be effectively embedded into the first relief groove.

[0052] The third lamination 131 mates with the axial extension 33. The outer periphery of the third lamination 131 has a groove, i.e., a second clearance groove, to limit and reinforce the axial extension 33. For example, the outer diameter of the third lamination 131 is X (mm), the groove width is 2-5 mm, and the inner diameter is X-2 mm. At this point, the stator core 1 structure has the effect of fitting with the connecting structure 3. The third lamination 131, in conjunction with the axial extension 33, can effectively fix and constrain the axial extension 33 from one side. The axial extension 33 is a strip-shaped extension post, with a width ranging from 2-5 mm, less than the width of a single tooth. A single tooth ensures that the annular contact post is installed on only one tooth (the stator has twelve slots, i.e., twelve identical stator teeth).

[0053] The inner diameter of the annular structure 31 is X-2 (mm), which is tightly embedded in the recessed part of the stator core 1. The outer diameter is X+2 (mm). At this time, the wall thickness of the annular connecting component is 4mm, which has a certain strength and can avoid injection molding deformation. The height Z of the annular connecting component is in the range of 1-3 (mm) (preferably 2mm). At this time, the second lamination 121 should have 4 pieces (for example, each piece has a plastic-coated structure of 0.5 mm).

[0054] The axial extension 33 and the connector 32 form an L-shaped bracket. The connector 32 is a connecting plate. The plate surface of the connecting plate is parallel to the load bracket surface (i.e., the support structure) of the mounting angle contact, and the connector 32 is exposed in the plastic cover to achieve the purpose of contacting the load mounting bracket, i.e., the support structure. At this time, the intersection surface of the first punch 111 and the second punch 121 forms the mounting angle contact load bracket surface. The axial extension 33 of the L-shaped bracket contacts the end cover 2. At this time, the axial height H of the axial extension is the distance between the mounting angle contact load bracket surface and the contact surface of the end cover 2.

[0055] The connection structure 3 of this application is composed of a ring structure 31 and an L-shaped bracket. The stator core 1 is embedded in the ring structure 31. The upper side of the L-shaped bracket contacts the end cover 2. The height H is the height of the axial extension, that is, the distance from the support structure to the rear end cover 2. The inner diameter of the ring connection component is X-2 (mm) and the outer diameter is X+2 (mm). At this time, the thickness of the ring structure 31 (the distance from the inner circumference to the outer circumference) is less than 5 mm of plastic-coated structure, the optimal thickness is 3-5 mm of plastic-coated structure, and the even better thickness is 4 mm. This can ensure the contact function of the structure and will not affect the magnetic force trend of the teeth.

[0056] Meeting the embedding requirements and possessing high structural strength, the thickness of the annular structure 31 is Z, ranging from 1 to 3 mm (preferably 2 mm). After injection molding, the outer edge of the L-shaped plane is exposed outside the molding compound, making close contact and conducting with the load metal bracket. At this time, the annular connection structure 3 connects and conducts the end cap 2, stator core 1, and load mounting bracket. (e.g.) Figures 9-10 )

[0057] This application also discloses some embodiments, in which the stator structure further includes a plastic-coated structure; the stator core 1, the connecting structure 3 and the end cap 2 are plastic-encapsulated into an integral structure by the plastic-coated structure.

[0058] According to another aspect of this application, an electric motor is provided, including a stator structure, which is the stator structure described above. The motor also includes a rotor 7 and a shaft 6, with a permanent magnet 92 disposed on the rotor 7; the stator structure also includes a stator winding 91.

[0059] The method for manufacturing the motor described in this application is as follows:

[0060] Step 1: Design the core laminations and stator core 1 that meet the requirements based on the motor performance;

[0061] Step 2: Design a connection structure 3 that meets the requirements based on the stator core 1 design;

[0062] Step 3: Based on the stator core 1 with plastic coating, injection mold the stator assembly;

[0063] Step 4: Install the stator assembly according to the design to achieve the connection between end cover 2, iron core, and load support.

[0064] It will be readily understood by those skilled in the art that the aforementioned advantageous methods can be freely combined and superimposed without conflict.

[0065] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A stator structure, characterized in that, include: Stator core (1); End cap (2), the end cap (2) is a conductor, and the end cap (2) is disposed at one end of the stator core (1); The connection structure (3) further includes an annular structure (31), which is sleeved on the stator core (1) and electrically connected to the stator core (1); the connection structure (3) is electrically connected to the end cover (2); the connection structure (3) includes an axial extension (33), which is connected to the annular structure (31) and extends along the central axis of the annular structure (31); the axial extension (33) extends to one end of the stator core (1) so that the axial extension (33) contacts the end cover (2), thereby making the axial extension (33) electrically connected to the end cover (2).

2. The stator structure according to claim 1, characterized in that, The connecting structure (3) can be electrically connected to the supporting structure, which is used to support the structure to be installed; the connecting structure (3) has a connecting hole; the fastening structure can pass through the connecting hole to fasten the connecting structure (3) to the supporting structure, thereby making the connecting structure (3) electrically connected to the supporting structure.

3. The stator structure according to claim 2, characterized in that, The connection structure (3) includes a connector (32), which is disposed on the outer periphery of the annular structure (31); the connection hole (321) is disposed on the connector (32).

4. The stator structure according to claim 1, characterized in that, A second clearance groove is provided on the outer surface of the stator core (1), and the axial extension (33) is provided in the second clearance groove.

5. The stator structure according to claim 1, characterized in that, A first clearance groove is provided on the outer surface of the stator core (1), and the annular structure (31) is disposed in the first clearance groove.

6. The stator structure according to any one of claims 1-5, characterized in that, The stator core (1) is made of lamination assembly; the lamination assembly includes a first lamination group (11), a second lamination group (12) and a third lamination group (13); the first lamination group (11) includes at least one first lamination (111); the second lamination group (12) includes at least one second lamination (121); the third lamination group (13) includes at least one third lamination (131); the first lamination group (11), the second lamination group (12) and the third lamination group (13) are stacked sequentially; the outer diameter of the second lamination (121) is smaller than the outer diameter of the first lamination (111); the outer diameter of the second lamination (121) is smaller than the outer diameter of the third lamination (131); when a first clearance groove is provided on the outer surface of the stator core (1), the first clearance groove is formed on the outer periphery of the second lamination group (12).

7. The stator structure according to claim 6, characterized in that, When a second clearance groove is provided on the outer surface of the stator core (1), a groove is provided on the outer periphery of the third lamination group (13), and the groove forms the second clearance groove.

8. The stator structure according to claim 1, characterized in that, The stator structure also includes a plastic-coated structure; the stator core (1), the connecting structure (3), and the end cap (2) are encapsulated into an integrated structure by the plastic-coated structure.

9. An electric motor, characterized in that, The stator structure is the stator structure according to any one of claims 1-8.

Images