Motor plastic package stator assembly

Abstract

The motor plastic package stator assembly comprises a magnetic shoe, a grounding piece, a metal magnetic conductive ring, a bearing, a gasket and a plastic shell, the metal magnetic conductive ring is located on the outer side of the circumference of the magnetic shoe, the grounding piece is fixedly connected with the metal magnetic conductive ring, the gasket is arranged below the bearing and is coated at the bottom of the plastic shell, and the inner diameter of the bearing is larger than the outer diameter of the gasket. The plastic casing covers and fixes the metal magnetic conductive ring, the grounding sheet, the magnetic shoe, the bearing and the gasket. According to the plastic package stator assembly of the motor, the magnetic shoe, the grounding piece, the metal magnetic conductive ring, the bearing and the gasket are fixed in a plastic package mode while the plastic shell is formed in an injection molding mode, the assembly time of the stator is shortened, the assembly efficiency is improved, and the cost is reduced.

Description

Technical Field

[0001] The invention relates to a motor, and more particularly to a plastic-sealed stator assembly of a motor. Background Art

[0002] As market competition becomes increasingly fierce, companies are facing increasing cost pressure. In order to maintain competitive advantage, reducing product costs is of great significance to the company's overall cost reduction and efficiency improvement strategy. Summary of the invention

[0003] In order to achieve the above-mentioned purpose of reducing product cost, the present invention provides a motor plastic-sealed stator assembly.

[0004] According to the present invention, the motor plastic-sealed stator assembly includes a magnetic tile, a grounding plate, a metal magnetic ring, a bearing, a gasket and a plastic casing, wherein the metal magnetic ring is located outside the circumference of the magnetic tile, the grounding plate is fixedly connected to the metal magnetic ring, the gasket is arranged below the bearing and is plastic-coated at the bottom of the plastic casing, the inner diameter of the bearing is larger than the outer diameter of the gasket, and the plastic casing plastic-coats and fixes the metal magnetic ring, the grounding plate, the magnetic tile, the bearing and the gasket.

[0005] In a preferred embodiment, the plastic housing has four first cavities, and four first positioning inserts are inserted into the first cavities during the overmolding process to position the magnetic tile in the circumferential direction.

[0006] In a preferred embodiment, below the first cavity, the plastic housing is integrally formed with four positioning posts to fix the magnetic tile in a circumferential direction.

[0007] In a preferred embodiment, the plastic housing is integrally formed with four positioning plates to fix the metal magnetic ring and the magnetic tile in height direction.

[0008] In a preferred embodiment, the plastic housing has two symmetrically designed second cavities, and the bottom of the plastic housing has two symmetrically designed third cavities. Four second positioning inserts are inserted into the second and third cavities during the overmolding process to position the metal magnetic ring and magnetic tile in the height direction.

[0009] In a preferred embodiment, the metal magnetic conductive ring has a groove, and the enlarged portion of the grounding plate is fixed in the groove.

[0010] In a preferred embodiment, the plastic housing has two designed fourth cavities, and two third positioning inserts are inserted into the fourth cavities during the overmolding process to position the grounding plate in height and circumferential directions.

[0011] In a preferred embodiment, the plastic housing has three fifth cavities that are evenly distributed around the circumference, and three fourth positioning inserts are inserted into the fifth cavities during the overmolding process to position the bearing in height and circumferential directions.

[0012] In a preferred embodiment, the plastic housing has a sixth cavity located in the center, and a fifth positioning insert is inserted into the sixth cavity during the overmolding process to position the gasket in height and circumferential directions.

[0013] In a preferred embodiment, the plastic housing is integrally formed with a connector.

[0014] According to the motor plastic-sealed stator assembly of the present invention, the magnetic tiles, grounding plates, metal magnetic rings, bearings and gaskets are plastic-sealed and fixed while the plastic casing is injection-molded, thereby shortening the stator assembly time, improving assembly efficiency and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the assembly of a motor plastic-sealed stator assembly according to a preferred embodiment of the present invention.

[0016] Figure 2 yes Figure 1 Cross-sectional view of the motor's plastic-encapsulated stator assembly.

[0017] Figure 3 yes Figure 1 Assembly diagram of the motor's plastic-sealed stator assembly's housing, magnetic tiles, grounding plates and metal magnetic rings.

[0018] Figure 4 The figure shows the assembly method of magnetic tiles according to the prior art.

[0019] Figure 5 yes Figure 1 Schematic diagram of the partial structure of the motor plastic-sealed stator assembly.

[0020] Figure 6 yes Figure 1 Top view of the motor's plastic-encapsulated stator assembly.

[0021] Figure 7 yes Figure 1 Another cross-sectional view of the motor's plastic-encapsulated stator assembly.

[0022] Figure 8 yes Figure 1 Bottom view of the motor's plastic-sealed stator assembly.

[0023] Fig. 9 Show Figure 1 Positioning of bearings and washers during the specific injection molding process.

[0024] Fig.10 The figure shows the assembly method of the connector according to the prior art. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0026] The motor according to a preferred embodiment of the present invention is a PMDC (permanent magnet direct current) brushed motor, the housing is a plastic housing 6, and the stator structure is connected together with the plastic housing 6 by injection molding to form a plastic-sealed stator assembly, that is, the plastic housing 6 and the stator structure are integrally formed, which shortens the assembly time of the motor, improves the assembly efficiency, and reduces the cost. It should be understood that the PMDC brushed motor here is only used as an example and not a limitation, and the present invention is also applicable to brushless motors.

[0027] like Figure 1 and Figure 2 As shown, the stator structure includes a magnetic tile 1, a grounding plate 2, a metal magnetic ring 3, a bearing 4 and a gasket 5, and a plastic housing 6 is plastic-coated to fix the metal magnetic ring 3, the grounding plate 2, the magnetic tile 1, the bearing 4 and the gasket 5 to form a plastic-encapsulated stator assembly. In the specific injection molding process, the magnetic tile 1, the grounding plate 2, the metal magnetic ring 3, the bearing 4 and the gasket 5 are positioned in the mold through their respective positioning inserts, and then the plastic is injected along the plastic inlet to fix all the components (i.e., the magnetic tile 1, the grounding plate 2, the metal magnetic ring 3, the bearing 4 and the gasket 5) while forming the plastic housing 6.

[0028] In the prior art, the casing is formed by deep drawing of magnetic conductive materials, which is relatively costly. In the present invention, the casing is more of a plastic casing 6, and the added metal magnetic conductive ring 3 plays the role of magnetic conductivity of the original casing. The metal magnetic conductive ring 3 can be formed by coiling, which can reduce the cost compared to mass production of casings. In particular, the inventors found that if conventional thermoplastic plastics such as PA66 are used to form the plastic casing 6, due to its high molding temperature, the magnetic tile 1 as an insert may crack after injection molding. Therefore, the plastic casing 6 of the present invention uses low-temperature injection molding materials. The low temperature of the injection molding process will not cause the magnetic tile 1 to crack, and the precision requirements for parts are relatively low. Preferably, it is a bulk molding compound (Bulk Molding Compound, BMC) thermosetting material. The BMC material has a high hardness and meets the strength requirements of the motor. In other embodiments, it can also be a sheet molding compound (Sheet Molding Compound, SMC).

[0029] The magnetic tile 1 is a part of the stator structure, usually sintered from ferrite material. The grounding plate 2 is connected to the metal magnetic ring 3 to ensure a good conductive connection between the motor circuit grounding wire and the metal magnetic ring. The metal magnetic ring 3 interacts with the magnetic field of the magnetic tile 1 on the circumferential outer side of the magnetic tile 1 to enhance the magnetic flux and improve the magnetic field distribution. Figure 3 In the present invention, the magnetic tile 1, the grounding plate 2 and the metal magnetic ring 3 are integrally packaged by injection molding through the plastic housing 6, and the motor assembly line can reduce the assembly process of the magnetic tile 1, the grounding plate 2 and the metal magnetic ring 3, reduce the required equipment investment, improve production efficiency and reduce costs.

[0030] In the prior art, in order to ensure the performance and stability of the motor, the magnetic tile 1' is usually accurately positioned and fixedly assembled on the inner side of the housing 6' by means of magnetic tile glue 1a' and spring clip 1b', such as Figure 4 As shown. Specifically, the magnetic tile glue 1a' is applied on the surface of the magnetic tile 1' facing the housing 6', and two spring clips 1b' are placed in the gap between adjacent magnetic tiles 1' to support the magnetic tile 1' through the tension of the spring clips 1b' to limit the circumferential direction, and the magnetic tile 1' is assembled in the housing 6' after heating, drying and fixing. The magnetic tile 1 of the present invention is integrally injection-molded and packaged by the plastic housing 6, and there is no need to use the magnetic tile glue 1a' and the spring clip 1b', thereby reducing the parts required to be assembled on the motor assembly line.

[0031] In the specific injection molding process, the magnetic tile 1 and the metal magnetic ring 3 are positioned and fixed in the circumferential direction and the height direction by the upper and lower positioning inserts. Figure 5 As shown, the plastic housing 6 has four first cavities 61, and four first positioning inserts are inserted into the first cavities 61 to position the magnetic tile 1 in the circumferential direction. Below the first cavities 61, the plastic housing 6 directly forms four positioning columns 62, as shown in FIG. Figure 6 As shown, the magnetic tile 1 is fixed in the circumferential direction. Figure 5 and Figure 7 As shown, the plastic housing 6 directly forms four positioning plates 63 to fix the magnetic tile 1 and the metal magnetic conductive ring 3 in the height direction.

[0032] In the specific injection molding process, such as Figure 6 As shown, the top of the plastic housing 6 has two second cavities 64 of symmetrical design, such as Figure 8 As shown, the bottom of the plastic housing 6 has two symmetrically designed third cavities 65, and four second positioning inserts are inserted into the second cavity 64 and the third cavity 65 to position the metal magnetic ring 3 and the magnetic tile 1 in the height direction.

[0033] like Figure 3 As shown, the top of the metal magnetic ring 3 has a groove 31, and the enlarged portion of the bottom end of the grounding plate 2 is fixed in the groove 31 by welding. Figure 6 As shown, the top of the plastic housing 6 also has a fourth cavity 66 with a spaced design, and two third positioning inserts are inserted into the fourth cavity 66 to position the grounding plate 2 in the height and circumferential directions. The present invention can reduce the volume of the metal magnetic ring 3 while completing the grounding function by adding the grounding plate 2 connected to the metal magnetic ring 3 at the contact position between the grounding wire and the stator structure.

[0034] The bearing 4 radially supports the rotor structure to allow the rotor structure to rotate inside the stator structure, and the gasket 5 is designed to be overmolded at the bottom of the plastic housing 6 (below the bearing 4), and axially supports the rotor structure to adjust the gap or reduce vibration and noise. In the present invention, the bearing 4 and the gasket 5 are integrally injection-molded and packaged through the plastic housing 6, and the motor assembly line can reduce the press-fitting process of the bearing and the gasket, reduce the required equipment investment, improve production efficiency, and reduce costs.

[0035] In the specific injection molding process, such as Fig. 9 As shown, the bearing 4 and the gasket 5 are positioned in the height direction and the circumferential direction by the lower mold and the fourth and fifth positioning inserts 8, 9. In particular, the inner diameter of the bearing 4 is larger than the outer diameter of the gasket 5, thereby leaving a fixed position for the fourth positioning insert 8, so that the bearing 4 and the gasket 5 can be integrally injection molded. Figure 8 As shown, the bottom of the plastic housing 6 also has three fifth cavities 67 that are evenly distributed in the circumference and a sixth cavity 68 located in the center, three fourth positioning inserts 8 are inserted into the fifth cavity 67 to position the bearing 4 in the height and circumferential directions, and a fifth positioning insert 9 is inserted into the sixth cavity 68 to position the gasket 5 in the height and circumferential directions.

[0036] Due to the different application scenarios and structures of the motor, the plastic housing 6 can be formed integrally with the connector or without the connector according to actual needs during molding and design. In this embodiment, the connector 69 is formed integrally with the plastic housing 6, and the terminal is fixed to the connector 69 by post-installation, thereby connecting the electrical part of the motor to the external circuit. In the prior art, the connector 69' is first installed into the carbon brush holder 69a', such as Fig.10 Obviously, the present invention can reduce the number of steps for installing the connector 69 into the brush holder, improve production efficiency and reduce costs.

[0037] The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The above embodiment of the present invention can also be modified in various ways. That is, all simple, equivalent changes and modifications made according to the claims and the description of the present invention fall within the scope of protection of the claims of the present invention. The contents not described in detail in the present invention are all conventional technical contents.

Claims

1. A motor plastic-sealed stator assembly, characterized in that: The motor plastic-sealed stator assembly includes a magnetic tile, a grounding plate, a metal magnetic ring, a bearing, a gasket and a plastic casing, wherein the metal magnetic ring is located outside the circumference of the magnetic tile, the grounding plate is fixedly connected to the metal magnetic ring, the gasket is arranged below the bearing and is plastic-coated at the bottom of the plastic casing, the inner diameter of the bearing is larger than the outer diameter of the gasket, and the plastic casing is plastic-coated to fix the metal magnetic ring, the grounding plate, the magnetic tile, the bearing and the gasket.

2. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The plastic housing has four first cavities, and four first positioning inserts are inserted into the first cavities during the overmolding process to position the magnetic tile in the circumferential direction.

3. The motor plastic-sealed stator assembly according to claim 1, characterized in that: Below the first cavity, the plastic housing is integrally formed with four positioning posts to fix the magnetic tile in a circumferential direction.

4. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The plastic housing is integrally formed with four positioning plates to fix the metal magnetic ring and magnetic tile in height direction.

5. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The plastic casing has two symmetrically designed second cavities, and the bottom of the plastic casing has two symmetrically designed third cavities. Four second positioning inserts are inserted into the second and third cavities during the overmolding process to position the metal magnetic ring and magnetic tile in the height direction.

6. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The metal magnetic conductive ring has a groove, and the enlarged part of the grounding plate is fixed in the groove.

7. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The plastic housing has two designed fourth cavities, and two third positioning inserts are inserted into the fourth cavities during the overmolding process to position the grounding plate in height and circumferential directions.

8. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The plastic housing has three fifth cavities which are evenly distributed around the circumference. Three fourth positioning inserts are inserted into the fifth cavities during the overmolding process to position the bearing in height and circumferential directions.

9. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The plastic housing has a sixth cavity located at the center, and a fifth positioning insert is inserted into the sixth cavity during the overmolding process to position the gasket in height and circumferential directions.

10. The motor plastic-sealed stator assembly according to claim 1, characterized in that: The plastic housing is integrally molded with connectors.

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