Coating method of motor winding

Abstract

The invention provides a coating method of a motor winding, which comprises the following steps of: 1, sinking at least one part of the end part of the motor winding of a stator below the liquid level of a fluidized bed, and enabling the stator to be inclined relative to the liquid level of the fluidized bed at the moment; 2, driving the end part of the motor winding to leave the liquid level of the fluidized bed; and thirdly, coating is completed, or the first step and the second step are executed again. According to the configuration, the motor winding sinks into the fluidized bed in an inclined posture, a sufficient gas exhaust passage is reserved, gas can be exhausted from the gas exhaust passage, the probability that a closed cavity is formed between the liquid level and the motor winding is reduced, a better coating effect is achieved, the insulating property is improved, and the failure rate and the repair rate of a stator are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of motors, and in particular to a coating method for motor windings. Background Art

[0002] With the development of new energy vehicles, the improvement of passenger car motors is also changing with each passing day. At present, in order to ensure the safety of motor products, the motor stator often uses two processes: insulating resin impregnation and epoxy resin powder end encapsulation to improve the insulation performance of the motor stator.

[0003] However, with the trend of high-voltage development of passenger car motors, the working voltage level of motors is getting higher and higher, and the requirements for insulation systems are also getting higher and higher. In addition, with the development of technology, the end length of the stator winding is shortened and the gap is reduced. For the stator winding, in the process of using traditional processes to encapsulate the end of epoxy resin powder, the epoxy resin powder liquid level in the fluidized bed is easy to combine with the winding structure itself to form a closed air cavity. The epoxy resin powder cannot enter the closed air cavity, and thus cannot completely cover the end of the stator winding, forming a process defect commonly known as "copper leakage", which seriously affects the safety of the motor. Summary of the invention

[0004] The object of the present invention is to provide a coating method for motor windings to solve the problem that the existing coating process is prone to process defects.

[0005] In order to solve the above technical problems, the present invention provides a coating method for motor windings, which comprises: Step 1: sinking at least a portion of the end of the motor winding of the stator below the liquid surface of the fluidized bed, while the stator is inclined to the liquid surface of the fluidized bed; Step 2: driving the end of the motor winding away from the liquid surface of the fluidized bed; Step 3: Complete the coating, or perform step 1 and step 2 again.

[0006] Optionally, after step 1, the motor winding coating method further comprises: Step 4: Swing and / or rotate the stator around the axis.

[0007] Optionally, step four is executed more than twice; in the adjacent steps four, the stator swings in different directions or rotates around the axis in different directions; or in the adjacent steps four, the stator swings and rotates around the axis in sequence.

[0008] Optionally, in step 4, the stator is maintained for a predetermined time after the oscillation stops or the rotation around the axis stops.

[0009] Optionally, after step 1, the motor winding coating method further comprises: Step 5: Align the stator so that the end of the motor winding is parallel to the liquid surface of the fluidized bed, and all parts of the end of the motor winding are sunk below the liquid surface of the fluidized bed.

[0010] Optionally, after step 5, the motor winding coating method further comprises: Step six: Rotate the motor winding around the axis.

[0011] Optionally, in step one, a portion of the end of the motor winding is above the liquid surface of the fluidized bed, a portion is below the liquid surface of the fluidized bed, and the center of the end is below the liquid surface of the fluidized bed.

[0012] Optionally, the motor winding is preheated before the end of the motor winding is sunk into the liquid surface of the fluidized bed; and / or, the motor winding is heated and cured after coating is completed.

[0013] Optionally, in step one, the inclination angle of the motor winding is 0°~40°.

[0014] Optionally, in step 1: Firstly, the stator is tilted so that the end of the motor winding of the stator is tilted toward the liquid surface of the fluidized bed, and then at least a part of the end of the motor winding is sunk below the liquid surface of the fluidized bed; or First, at least a portion of the end of the motor winding is sunk below the liquid surface of the fluidized bed, and then the stator is tilted so that the end of the motor winding of the stator is tilted to the liquid surface of the fluidized bed; or At the same time, the stator is tilted so that the end of the motor winding of the stator is tilted toward the liquid surface of the fluidized bed, and at least a part of the end of the motor winding is sunk below the liquid surface of the fluidized bed.

[0015] In summary, the coating method of the motor winding provided by the present invention includes: step one: sinking at least a part of the end of the motor winding of the stator below the liquid surface of the fluidized bed, at which time the stator is inclined to the liquid surface of the fluidized bed; step two: driving the end of the motor winding away from the liquid surface of the fluidized bed; step three: completing the coating, or performing step one and step two again.

[0016] With such configuration, by sinking the motor winding into the fluidized bed in an inclined posture, sufficient gas exhaust passages are left, through which the gas can be discharged, reducing the probability of forming a closed cavity between the liquid surface and the motor winding, achieving a better coating effect, improving the insulation performance, and reducing the failure rate and repair rate of the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Those skilled in the art will appreciate that the drawings are provided for a better understanding of the present invention, but do not constitute any limitation on the scope of the present invention.

[0018] Figure 1 4 is a flow chart of a method for coating motor windings according to an embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of the motor winding according to an embodiment of the present invention sinking into the fluidized bed in an inclined posture.

[0020] Figure 3 Schematic diagram of the motor winding swing according to an embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the motor winding swinging and moving downward at the same time according to an embodiment of the present invention.

[0022] Figure 5 It is a schematic diagram of a motor winding according to an embodiment of the present invention being sunk into a fluidized bed and aligned.

[0023] Figure 6 It is a schematic diagram of the motor winding rotating around the axis according to an embodiment of the present invention.

[0024] In the accompanying drawings: 1-stator; 10-motor winding; 11-iron core; 2-fluidized bed; 20-liquid surface. DETAILED DESCRIPTION

[0025] In order to make the purpose, advantages and features of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0026] As used in the present invention, the singular forms "one", "an", "one" and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, and "one end" and "the other end" and "the proximal end" and "the distal end" generally refer to two corresponding parts, which include not only the endpoints. The terms "step one", "step two" and "step three" are only used to describe the sequence number of the steps and cannot be understood as indicating or implying the order of the steps. In addition, as used in the present invention, "installed", "connected", "connected", and one element "set" on another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or one side of another element, unless the content clearly indicates otherwise. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used relative to the exemplary embodiments as shown in the figures, with the upward or upper direction toward the top of the corresponding figure, and the downward or lower direction toward the bottom of the corresponding figure.

[0027] The object of the present invention is to provide a coating method for motor windings to solve the problem that the existing coating process is prone to process defects.

[0028] Please refer to Figures 1 to 6 , an embodiment of the present invention provides a coating method for a motor winding, which comprises: Step 1 S1: sinking at least a portion of the end of the motor winding 10 of the stator 1 below the liquid surface 20 of the fluidized bed 2, and at this time, the stator 1 is inclined to the liquid surface 20 of the fluidized bed 2; Step 2 S2: driving the end of the motor winding 10 away from the liquid surface 20 of the fluidized bed 2; Step three S3: Complete coating, or perform step one S1 and step two S2 again.

[0029] In an exemplary embodiment, the overall shape of the stator 1 is generally an annular column around an axis A. The stator 1 includes an iron core 11 and a plurality of conductors (such as flat enameled wires) passing through the iron core 11. The conductors are bent at both axial ends passing through the iron core 11 so that conductors of the same phase can be connected to each other, such as by welding, to form a motor winding 10.

[0030] The motor winding 10 used in the motor winding coating method provided in this embodiment may be in the form of, for example but not limited to, X-pin, Hair-pin or I-pin. The twisted connection method of the conductor ends of different winding forms is different, and the specifics can be understood by referring to the prior art.

[0031] It is understandable that the welding of the conductor requires the removal of a portion of the conductor's insulation layer (such as paint), or the welding process may also affect and damage a portion of the insulation layer, which ultimately results in the presence of a portion of the conductor being affected by welding at both axial ends of the iron core 11. The end of the motor winding 10 referred to in this embodiment refers to the section of the conductor at both axial ends of the iron core 11 that is affected by welding. This section requires additional insulation coating because the original insulation layer is removed or damaged. Depending on the winding form or welding process, the end of the motor winding 10 can be simplified and abstractly understood as a plane (circle) perpendicular to the axis of the stator 1, or as a column (cylinder) with a certain thickness in the axial direction of the stator 1. When performing insulation coating, a fluidized bed 2 can be used, in which epoxy resin powder can be placed, and the liquid surface 20 is the outer package interface after the epoxy resin powder is suspended in the fluidized bed 2. The principle of the fluidized bed 2 can refer to the prior art, and this embodiment will not be described in detail.

[0032] Please refer to Figure 2 In step 1 S1, the stator 1 is inclined to the liquid surface 20 of the fluidized bed 2, which means that the axis A of the stator 1 and the direction B perpendicular to the liquid surface 20 of the fluidized bed 2 are arranged at a certain angle. The angle α of the stator 1 (the angle between the axis A of the stator 1 and the direction B perpendicular to the liquid surface 20 of the fluidized bed 2) is preferably 0° to 40°.

[0033] When at least a portion of the end of the motor winding 10 sinks below the liquid surface 20 of the fluidized bed 2, the stator 1 presents an inclined posture. To achieve this state, it can be achieved in the following ways: The stator 1 may be tilted first so that the end of the motor winding 10 of the stator 1 is tilted toward the liquid surface 20 of the fluidized bed 2, and then at least a portion of the end of the motor winding 10 is sunk below the liquid surface 20 of the fluidized bed 2; Alternatively, at least a portion of the end of the motor winding 10 may be sunk below the liquid surface of the fluidized bed 2, and then the stator 1 may be tilted so that the end of the motor winding 10 of the stator 1 is tilted toward the liquid surface 20 of the fluidized bed 2. The stator 1 can also be tilted at the same time so that the end of the motor winding 10 of the stator 1 is tilted toward the liquid surface 20 of the fluidized bed 2 , and at least a portion of the end of the motor winding 10 is sunk below the liquid surface 20 of the fluidized bed 2 .

[0034] Further, the direction in which the end of the motor winding 10 sinks into the liquid surface 20 of the fluidized bed 2 may be moved along a direction B perpendicular to the liquid surface 20 of the fluidized bed 2, or may be moved along the direction of the axis A of the stator 1. Optionally, in step 2 S2, the direction in which the end of the motor winding 10 is driven to leave the liquid surface 20 of the fluidized bed 2 may be moved along a direction B perpendicular to the liquid surface 20 of the fluidized bed 2, or may be moved along the direction of the axis A of the stator 1. In some embodiments, the movement direction of the end of the motor winding 10 (that is, the movement direction of the stator 1) may also be along a direction between the direction B and the direction of the axis A. This embodiment is not limited to this.

[0035] Step 3 S3 is performed after step 1 S1 and step 2 S2. In some embodiments, the end of the motor winding 10 is tilted and sunk into the fluidized bed 2 and lifted out of the fluidized bed 2. After one leaching is completed, the coating thickness of the epoxy resin powder can be further tested. If the coating thickness meets the requirements, the coating is completed. If the coating thickness does not meet the requirements, the step 1 S1 and step 2 S2 can be returned and repeated, that is, at least part of the end of the motor winding 10 is sunk into the liquid surface 20 of the fluidized bed 2 again to repeat the coating.

[0036] In step 1 S1, in some embodiments, for example, when the angle α of the inclination of the stator 1 is small, the end of the motor winding 10 can be completely sunk into the liquid surface 20 of the fluidized bed 2. At this time, the exhaust process of the end occurs during the sinking process, or the exhaust is achieved by swinging or rotating in the subsequent step 4 S4 (see the following description for details). In other embodiments, for example, when the angle α of the inclination of the stator 1 is large, when a part of the end of the motor winding 10 sinks below the liquid surface 20 of the fluidized bed 2, another part of the end of the motor winding 10 is above the liquid surface 20 of the fluidized bed 2, such as Figure 3 Preferably, when a portion of the end of the motor winding 10 is above the liquid surface 20 of the fluidized bed 2 and a portion of the end is below the liquid surface 20 of the fluidized bed 2, the center of the end of the motor winding 10 (i.e., the intersection of the end of the motor winding 10 and the axis A) is below the liquid surface 20 of the fluidized bed 2, so as to prevent the center point or center area of ​​the end from being unable to contact the epoxy resin powder during subsequent swinging or rotation.

[0037] Please refer to Figures 2 to 4, Optionally, after the step 1 S1, the coating method of the motor winding further includes: step 4 S4: swinging and / or rotating the stator 1 around the axis. In step 4 S4, the swinging of the stator 1 means that the stator 1 rotates around a swing axis perpendicular to the axis A. When the stator 1 swings, the inclination angle α of the stator 1 gradually decreases. When the inclination angle α of the stator 1 is zero, the stator 1 is in a straightened state, and its axis A is perpendicular to the liquid surface 20 of the fluidized bed 2. In some embodiments, after the stator 1 is straightened, it can jump to step 2 S2 and step 3 S3 to complete the coating. In other embodiments, after the stator 1 is straightened, the stator 1 can continue to swing in the opposite direction, and the inclination angle α gradually increases. During the swinging process, the part of the end of the motor winding 10 that sank into the liquid surface 20 of the fluidized bed 2 in step 1 S1 is released from the liquid surface 20, and the part of the end that was originally on the liquid surface 20 sinks into the liquid surface 20 of the fluidized bed 2. It should be noted that the swinging angle of the stator 1 in step 4 S4 is not necessarily the same as the tilting angle of the stator 1 in step 1 S1 .

[0038] Please refer to Figure 6 When the stator 1 rotates around the axis A, the inclination angle α of the stator 1 may remain unchanged. As the stator 1 rotates around the axis A, the end portion of the motor winding 10 that sinks into the liquid surface 20 of the fluidized bed 2 in step 1 S1 is released from the liquid surface 20, and the end portion that was originally on the liquid surface 20 sinks into the liquid surface 20 of the fluidized bed 2. In some embodiments, the swinging and rotation around the axis A of the stator 1 may also be performed simultaneously. After step 4 S4 is completed, the process may jump to step 2 S2 and step 3 S3.

[0039] Optionally, step four S4 is executed more than twice; in the adjacently executed step four S4, the stator 1 swings in different directions or rotates around the axis A in different directions; or in the adjacently executed step four S4, the stator 1 swings and rotates around the axis A in sequence. That is to say, in the process of repeatedly executing step four S4, the stator 1 is equivalent to swinging back and forth, or rotating forward and reversely, or, after the stator 1 swings once, it subsequently rotates around the axis A once, and then swings again, and so on. Furthermore, the stator 1 maintains a predetermined time after the swinging stops or the rotation around the axis A stops. After each step four S4 is executed, the stator 1 can remain stationary for a period of time to facilitate gas discharge.

[0040] Whether the stator 1 is swung or rotated around the axis A, all parts of the end of the motor winding 10 can be sunk into the liquid surface 20 of the fluidized bed 2 to achieve the coating of epoxy resin powder. In addition, by tilting, swinging or rotating the stator 1 around the axis A, the gas can be effectively discharged, the probability of forming a closed cavity can be reduced, and a better coating effect can be achieved. In particular, in some embodiments, the swinging and the rotation around the axis A can be combined and applied simultaneously, that is, the stator 1 rotates around the axis A while swinging. In this way, a better exhaust effect can be achieved.

[0041] Step 4 S4 may be executed more than twice continuously, or may be executed more than twice at intervals. For example, in one embodiment, the steps may be executed in the order of step 1 S1, step 4 S4, step 2 S2, step 3 S3, step 1 S1, step 4 S4, step 2 S2, step 3 S3, and in this case, step 4 S4 is executed twice at intervals.

[0042] Please refer to Figure 4 and Figure 5 Furthermore, the coating method of the motor winding also includes: Step five S5: straighten the stator 1 so that the end of the motor winding 10 is parallel to the liquid surface 20 of the fluidized bed 2, and all parts of the end of the motor winding 10 are sunk below the liquid surface 20 of the fluidized bed 2. Step five S5 can be performed after the coating is completed in step three S3, that is, the stator 1 can be straightened after the end of the motor winding 10 is lifted off the liquid surface 20 of the fluidized bed 2. Optionally, step five S5 can also be performed before step two S2, that is, the stator 1 is straightened first, and then the end of the motor winding 10 is lifted off the liquid surface 20 of the fluidized bed 2. Optionally, step five S5 can also be performed during step four S4, that is, the stator 1 is straightened during the swinging or rotating process of the stator 1.

[0043] Optionally, after step five S5, the motor winding coating method further includes: Step six S6: Rotate the stator 1 around the axis A. Step six S6 is preferably performed when the end of the motor winding 10 is still below the liquid level 20 of the fluidized bed 2. When the stator 1 is aligned and the end of its motor winding 10 is still below the liquid level 20 of the fluidized bed 2, the stator 1 is driven to rotate around the axis A at a certain angle so that the end of its motor winding 10 can fully contact the epoxy resin powder. After stopping the rotation, it is optional to keep still for a certain period of time to improve the bonding effect of the epoxy resin powder. After completing step six S6, it is possible to return to step two S2, lift the end of the motor winding 10 away from the liquid level 20 of the fluidized bed 2, and then complete the coating in step three S3.

[0044] After one end of the motor winding 10 is coated, the stator 1 can be turned over, and the other end of the motor winding 10 can also be coated using the motor winding coating method provided in this embodiment.

[0045] Optionally, the coating method of the motor winding also includes: preheating the motor winding 10 before sinking the end of the motor winding 10 into the liquid surface 20 of the fluidized bed 2; and / or, heating and curing the motor winding 10 after coating. In one embodiment, the motor winding 10 is preheated or heat-cured, for example, the entire stator 1 can be heated to improve the bonding effect of the epoxy resin powder. Then, a manipulator or a clamping device mechanism can be used to clamp the preheated stator 1, and perform subsequent tilting, sinking, swinging or rotating operations. Optionally, the heating method for preheating and heat curing is not limited, and can be selected from oven heating, infrared heating or induction heating.

[0046] In summary, the coating method of the motor winding provided by the present invention comprises: step 1: sinking at least a part of the end of the motor winding of the stator under the liquid surface of the fluidized bed, at which time the stator is inclined to the liquid surface of the fluidized bed; step 2: driving the end of the motor winding away from the liquid surface of the fluidized bed; step 3: completing the coating, or performing the steps 1 and 2 again. With such a configuration, by sinking the motor winding into the fluidized bed in an inclined posture, sufficient gas discharge passages are left, from which the gas can be discharged, reducing the probability of forming a closed cavity between the liquid surface and the motor winding, achieving a better coating effect, improving the insulation performance, and reducing the failure rate and rework rate of the stator.

[0047] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the protection scope of the present invention.

Claims

1. A coating method for motor windings, characterized in that: include: Step 1: sinking at least a portion of the end of the motor winding of the stator below the liquid surface of the fluidized bed, while the stator is inclined to the liquid surface of the fluidized bed; Step 2: driving the end of the motor winding away from the liquid surface of the fluidized bed; Step 3: Complete the coating, or perform step 1 and step 2 again.

2. The coating method for motor windings according to claim 1, characterized in that: After step 1, the coating method of the motor winding further comprises: Step 4: Swing and / or rotate the stator around the axis.

3. The coating method for motor windings according to claim 2, characterized in that: The step four is executed more than twice; in the adjacent steps four, the stator swings in different directions or rotates around the axis in different directions; or in the adjacent steps four, the stator swings and rotates around the axis in sequence.

4. The coating method for motor windings according to claim 2, characterized in that: In the step 4, the stator is maintained for a predetermined time after the oscillation stops or the rotation around the axis stops.

5. The coating method for motor windings according to claim 1, characterized in that: After step 1, the coating method of the motor winding further comprises: Step 5: Align the stator so that the end of the motor winding is parallel to the liquid surface of the fluidized bed, and all parts of the end of the motor winding are sunk below the liquid surface of the fluidized bed.

6. The coating method for motor windings according to claim 5, characterized in that: After step 5, the coating method of the motor winding further comprises: Step six: Rotate the motor winding around the axis.

7. The coating method for motor windings according to claim 1, characterized in that: In the step 1, a portion of the end of the motor winding is above the liquid surface of the fluidized bed, a portion is below the liquid surface of the fluidized bed, and the center of the end is below the liquid surface of the fluidized bed.

8. The coating method for motor windings according to claim 1, characterized in that: The motor winding is preheated before the end of the motor winding is sunk into the liquid surface of the fluidized bed; and / or the motor winding is heated and cured after coating.

9. The coating method for motor windings according to claim 1, characterized in that: In step 1, the inclination angle of the motor winding is 0°~40°.

10. The coating method for motor windings according to claim 1, characterized in that: In step one: Firstly, the stator is tilted so that the end of the motor winding of the stator is tilted toward the liquid surface of the fluidized bed, and then at least a part of the end of the motor winding is sunk below the liquid surface of the fluidized bed; or First, at least a portion of the end of the motor winding is sunk below the liquid surface of the fluidized bed, and then the stator is tilted so that the end of the motor winding of the stator is tilted to the liquid surface of the fluidized bed; or At the same time, the stator is tilted so that the end of the motor winding of the stator is tilted toward the liquid surface of the fluidized bed, and at least a part of the end of the motor winding is sunk below the liquid surface of the fluidized bed.

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