Motor assembly, water pump and water heater

Abstract

The utility model discloses a motor assembly, a water pump and a water heater, the motor assembly comprises a shielding piece, a rotor assembly, a stator assembly and a plastic package piece, the shielding piece comprises a body part and an end plate, the end plate is connected to one end of the body part and arranged around the periphery of the body part, and the body part is provided with an inner cavity; the rotor assembly is rotationally arranged in the inner cavity; the stator assembly is annular, sleeves the outer side of the body part and is arranged around the rotor assembly; the plastic package part wraps the stator assembly and the end, away from the end plate, of the body part, and the plastic package part is connected with the end plate. The motor assembly provided by the utility model can simplify the production process, improve the production efficiency and reduce the production cost.

Description

Technical Field

[0001] This utility model relates to the field of water pump technology, and in particular to a motor assembly, a water pump and a water heater. Background Technology

[0002] Existing water heater pumps typically use a shielding sleeve to prevent water, dust, and other foreign objects from entering the stator. Generally, the shielding sleeve has an annular cavity, the stator is fitted into this cavity, and epoxy resin is poured into the cavity to fix the stator and improve its waterproofness. However, epoxy resin is expensive, and after pouring, it requires baking and other curing processes, as well as expensive Teflon material for demolding. This multi-step process is complex, resulting in low production efficiency and high overall production costs for the water pump. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a motor assembly that simplifies the production process, improves production efficiency, and reduces production costs.

[0004] This utility model also provides a water pump and a water heater having the above-mentioned motor assembly.

[0005] According to a first aspect of the present invention, a motor assembly includes a shielding component, a body portion and an end plate, the end plate being connected to one end of the body portion and arranged around the outer periphery of the body portion, the body portion having an inner cavity; a rotor assembly rotatably disposed in the inner cavity; a stator assembly being annular and sleeved on the outer side of the body portion and arranged around the rotor assembly; and a molding compound covering the stator assembly and the end of the body portion opposite to the end plate, and the molding compound being connected to the end plate.

[0006] The motor assembly according to the first aspect of the present invention has at least the following beneficial effects: by setting a molding compound and covering the stator assembly and the end of the body portion away from the end plate, and connecting the molding compound to the end plate, the shielding component, the stator assembly and the molding compound are injection molded into one piece, eliminating the need for potting, baking and other processes, effectively simplifying the production process of the motor assembly, shortening the production cycle, improving production efficiency, and eliminating the need for tooling made of special materials for demolding, effectively reducing production costs.

[0007] According to some embodiments of the present invention, a portion of the structure of the molding compound fills the gap between the shielding component and the stator assembly.

[0008] According to some embodiments of this utility model, the shielding component is a plastic component or a stainless steel component.

[0009] According to some embodiments of the present invention, the shielding member further includes a plurality of ribs, which are connected to the outer peripheral wall of the body and are arranged at intervals along the circumference of the body. The stator assembly includes a plurality of winding slots, which are arranged at intervals along the circumference and have their openings facing the center of the stator assembly. The plurality of ribs are correspondingly inserted into the slots of the plurality of winding slots.

[0010] According to some embodiments of the present invention, the end plate is provided with a groove on the side facing the stator assembly, the groove is arranged circumferentially along the body portion, the stator assembly includes a plurality of windings arranged sequentially along the circumferential direction of the stator assembly, and a portion of the structure of the plurality of windings is accommodated in the groove.

[0011] According to some embodiments of the present invention, the groove wall and / or the wall surface of the body portion away from the end plate are provided with protrusions, and the protrusions are embedded in the plastic sealant.

[0012] According to some embodiments of the present invention, the motor assembly further includes a lead wire clamp, the stator assembly includes a lead wire, the lead wire is fixed to the lead wire clamp, and the plastic seal further covers at least a portion of the structure of the lead wire clamp.

[0013] According to some embodiments of the present invention, the lead clamp is located on the outer side of the encapsulation along the radial direction of the stator assembly.

[0014] According to some embodiments of the present invention, the end plate is provided with a plurality of first fixing holes, the plurality of first fixing holes being arranged at intervals along the circumference of the stator assembly, and the molding compound is provided with a plurality of second fixing holes, the plurality of second fixing holes being correspondingly connected to the plurality of first fixing holes.

[0015] According to some embodiments of the present invention, the rotor assembly includes a magnetic ring, the stator assembly includes a stator core, the stator core is arranged around the magnetic ring, the minimum inner diameter of the stator core is D1, and the maximum outer diameter of the magnetic ring is D3, satisfying: 0.04≤(D1-D3) / (2*D1)≤0.06.

[0016] According to some embodiments of the present invention, the stator assembly includes a stator core, the minimum inner diameter of the stator core is D1, and the maximum outer diameter of the stator core is D2, satisfying: 1.6≤D2 / D1≤2.

[0017] According to some embodiments of the present invention, the rotor assembly includes a magnetic ring, the magnetic ring includes a plurality of annular portions, the plurality of annular portions being coaxial and sequentially spliced ​​along the axial direction of the rotor assembly.

[0018] A water pump according to a second aspect of the present invention includes an impeller and a motor assembly according to a first aspect of the present invention, wherein the impeller is fixedly connected to the rotor assembly.

[0019] The water pump according to the second aspect of the present invention has at least the following beneficial effects: Since the water pump adopts the above-mentioned motor assembly, by setting a molding compound and covering the stator assembly and the end of the body away from the end plate, and the molding compound is connected to the end plate, the shielding component, the stator assembly and the molding compound are injection molded into one piece, eliminating the processes of potting glue and baking, shortening the production cycle, effectively simplifying the production process of the motor assembly, improving production efficiency, and eliminating the need to use tooling made of special materials for demolding, effectively reducing production costs.

[0020] The water heater according to the third aspect of the present invention includes the water pump of the second aspect of the present invention.

[0021] The water heater according to the third aspect of the present invention has at least the following beneficial effects: the water heater uses the above-mentioned water pump, and by setting a molding compound and covering the stator assembly and the end of the main body away from the end plate, and the molding compound is connected to the end plate, the shielding component, the stator assembly and the molding compound are injection molded into one piece, eliminating the need for potting, baking and other processes, effectively simplifying the production process of the motor assembly, shortening the production cycle and improving production efficiency, and eliminating the need for tooling made of special materials for demolding, effectively reducing production costs.

[0022] 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

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0024] Figure 1 This is a schematic diagram of the structure of the stator assembly, shielding sleeve, and plastic sealant assembled in an embodiment of this utility model;

[0025] Figure 2 yes Figure 1 The diagram shows the decomposed structure.

[0026] Figure 3 This is a cross-sectional view of the motor assembly in an embodiment of this utility model;

[0027] Figure 4 This is a schematic diagram of the shielding component in an embodiment of this utility model;

[0028] Figure 5 This is an axial schematic diagram of the stator assembly (with the windings hidden) in an embodiment of this utility model;

[0029] Figure 6 This is a cross-sectional view of a magnetic ring according to other embodiments of this utility model.

[0030] Figure label:

[0031] Shielding component 100; Body part 110; Rib 111; Inner cavity 112; End plate 120; Groove 121; Protrusion 130; First mounting ear 140; First fixing hole 141;

[0032] Stator assembly 200; stator core 210; yoke 211; tooth 212; winding 220; winding slot 230; slot opening 231; air gap 240;

[0033] Plastic sealant 300; end wall 310; annular peripheral wall 320; second mounting ear 330; second fixing hole 331;

[0034] Cable clip 400;

[0035] Magnetic ring 500; Annular part 510. Detailed Implementation

[0036] 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.

[0037] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0038] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0039] In the description of this utility model, unless otherwise explicitly defined, terms such as setting, installing, connecting, assembling, and cooperating should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0040] Reference Figures 1 to 6 As shown, the first aspect of this utility model provides a motor assembly for use in a water pump of a water heater, such as a gas water heater pump. The motor assembly includes a shield 100, a rotor assembly, a stator assembly 200, and a plastic sealant 300.

[0041] Reference Figure 4 As shown, it can be understood that the shielding member 100 includes a body portion 110 and an end plate 120. The body portion 110 is generally columnar in shape, and the end plate 120 is annular in shape. The end plate 120 is connected to one end of the body portion 110 along the central axis of the body portion 110, and the end plate 120 is arranged around the outer periphery of the body portion 110. The end plate 120 and the body portion 110 are an integral structure.

[0042] Reference Figure 3 As shown, it can be understood that the body portion 110 is provided with an inner cavity 112, and the opening of the inner cavity 112 faces the side of the shield 100 where the end plate 120 is provided. The rotor assembly is rotatably disposed in the inner cavity 112. Specifically, the rotor assembly includes a magnetic ring 500, that is, the magnetic ring 500 is rotatably disposed within the inner cavity 112.

[0043] In other embodiments, reference is made to Figure 6 As shown, it is understandable that for high-performance motor assemblies, the axial length of the magnetic ring 500 is relatively large, making machining more difficult while ensuring accuracy. Therefore, the magnetic ring 500 includes multiple annular portions 510, which are sequentially spliced ​​along the axial direction of the rotor assembly. Thus, the magnetic ring 500 is manufactured by using multiple annular portions 510 spliced ​​along the axial direction of the rotor assembly. Each annular portion 510 has a shorter axial length, reducing machining difficulty and improving machining efficiency while ensuring the accuracy of the magnetic ring 500.

[0044] Of course, the structure of the rotor assembly is not limited to the magnetic ring 500; it can also consist of a rotor core and multiple magnetic tiles, which will not be elaborated here.

[0045] Reference Figure 2 and Figure 5As shown, the stator assembly 200 includes a stator core 210 and multiple windings 220. The stator core 210 is annular and typically consists of multiple core laminations stacked along the axial direction of the stator assembly 200. The stator core 210 includes a yoke 211 and multiple teeth 212. The yoke 211 is annular, and the multiple teeth 212 are all connected to the inner peripheral wall of the yoke 211 and are equally spaced along the circumference of the yoke 211. A winding slot 230 is defined between two adjacent teeth 212, meaning the multiple winding slots 230 are spaced apart along the circumference of the stator assembly 200. The openings of the winding slots 230 face the center of the stator assembly 200, meaning the openings of the winding slots 230 face the central axis of the stator core 210 along the radial direction of the stator assembly 200. The multiple windings 220 are respectively wound around multiple core units and accommodated in the winding slots 230. The stator assembly 200 is fitted around the outer periphery of the body portion 110, meaning the stator core 210 is fitted around the outer periphery of the body portion 110, and the direction of the central axis of the stator core 210 is parallel to the direction of the central axis of the body portion 110. Simultaneously, the stator core 210 is also arranged around the outer periphery of the rotor assembly (i.e., the magnetic ring 500). The direction of the central axis of the stator core 210 is the axial direction of the stator assembly 200.

[0046] Reference Figure 2 As shown, it can be understood that, along the axial direction of the stator assembly 200, both ends of the winding 220 protrude from the two end faces of the stator core 210. The end of the winding 220 facing the end plate 120 abuts against the end plate 120. Therefore, the end plate 120 can position the stator assembly 200, facilitating assembly.

[0047] Reference Figure 1 and Figure 3 As shown, it can be understood that the molding compound 300 is a plastic part manufactured through injection molding. The molding compound 300 covers the stator assembly 200 and the end of the body portion 110 opposite to the end plate 120, and the molding compound 300 is connected to the end plate 120. Specifically, the molding compound 300 includes an end wall 310 and an annular peripheral wall 320 connected to the periphery of the end wall 310. The annular peripheral wall 320 covers the outer periphery of the stator assembly 200, that is, the annular peripheral wall 320 covers the outer peripheral wall of the stator core 210. The end wall 310 covers the side of the stator assembly 200 opposite to the end plate 120 and the end face of the body portion 110 opposite to the end plate 120. The annular peripheral wall 320, at the end opposite to the end wall 310, is fitted to the side of the end plate 120 facing the encapsulation 300, and the annular peripheral wall 320 is bonded and fixed to the end plate 120 to achieve a sealed connection between the annular peripheral wall 320 and the end plate 120. Therefore, the stator assembly 200 is enclosed between the shield 100 and the encapsulation 300, which can meet the water pressure requirements of the water pump's water pressure test and prevent water, dust, and other foreign objects from entering the stator assembly 200, effectively reducing the failure rate and extending its service life.

[0048] Understandably, during the production of the motor assembly, the assembled stator assembly 200 is fitted onto the body 110 of the shield 100. The stator assembly 200 and the shield 100 assembly are then placed into an injection mold. Molten plastic is injected into the mold, completely covering the stator assembly 200 and the end of the body 110 facing away from the end plate 120. After the molten plastic cools and solidifies, the molding compound 300, the shield 100, and the stator assembly 200 are injection molded together, with the stator assembly 200 encased between the molding compound 300 and the shield 100. This prevents water, dust, and other foreign matter from entering the stator assembly 200, reducing the failure rate. This process eliminates the need for epoxy resin filling and baking, effectively simplifying the motor assembly production process, shortening the production cycle, and improving production efficiency.

[0049] Understandably, the molding compound 300 is made of unsaturated polyester bulk molding compound (i.e., BMC material). Unsaturated polyester bulk molding compound has the advantages of low price and high thermal conductivity, which can reduce the production cost of the motor assembly, while effectively improving the heat dissipation capacity of the motor assembly and reducing temperature rise.

[0050] Understandably, since the motor assembly is installed in the water pump, the shield 100 is constantly in contact with water. Therefore, the shield 100 is required to have good corrosion resistance.

[0051] Therefore, it is understandable that the shielding component 100 is a plastic part. For example, the material of the shielding component 100 may be the same as that of the molding compound 300. Alternatively, the shielding component 100 may be made of polyphenylene sulfide (PPS) and processed through injection molding. PPS is a special engineering plastic with advantages such as high mechanical strength, strong chemical resistance, high hardness, and good thermal stability, effectively improving the overall structural strength of the motor assembly and reducing the rate of water corrosion, thus improving structural stability. Alternatively, the shielding component 100 may be made of polyamide (commonly known as nylon, PA) and processed through injection molding. Polyamide has advantages such as light weight, excellent mechanical strength, wear resistance, and good corrosion resistance, which can reduce the overall weight of the motor assembly, meet lightweight design requirements, reduce the rate of water corrosion, and improve structural stability.

[0052] It is understood that in some embodiments, the shielding component 100 may also be made of stainless steel, manufactured through a casting process. Stainless steel possesses excellent corrosion resistance, strength, and heat resistance, which can further improve the structural strength of the shielding component 100, thereby increasing the overall structural strength of the motor assembly and effectively reducing the rate of water corrosion, thus improving structural stability. Simultaneously, it allows the shielding component 100 to fit more closely to the molding compound 300, improving sealing performance to meet the higher water pressure requirements of the hydrostatic test.

[0053] Therefore, by setting up a molding compound 300 and covering the stator assembly 200 and the end of the body 110 away from the end plate 120 with the molding compound 300 connected to the end plate 120, the shield 100, the stator assembly 200 and the molding compound 300 are injection molded into one piece, eliminating the need for potting, baking and other processes, effectively simplifying the production process of the motor assembly, shortening the production cycle, improving production efficiency, and eliminating the need for tooling made of special materials for demolding, effectively reducing production costs.

[0054] Meanwhile, since the plastic encapsulation 300 is directly encapsulated in the stator assembly 200 and the shield 100, there is no need to install an end cap on one end of the shield 100, which effectively shortens the axial height of the motor assembly in the stator assembly 200 and reduces the installation space required for the motor assembly.

[0055] Understandably, a portion of the structure of the molding compound 300 fills the gap between the shield 100 and the stator assembly 200. Specifically, the molding compound 300 is manufactured using an injection molding process. During injection molding, the molten plastic inevitably flows into and fills the gap between the shield 100 and the stator assembly 200. This improves the installation stability of the stator assembly 200 and enhances the bonding strength between the molding compound 300 and the stator assembly 200 and the shield 100, thereby improving the overall structural strength of the motor assembly and enhancing its waterproof performance.

[0056] Reference Figure 2 and Figure 3As shown, it can be understood that in the stator core 210, a winding slot 230 is defined between two adjacent core units. The winding slot 230 has a slot opening 231 facing the central axis of the stator core 210. To improve the installation stability of the stator assembly 200, the shield 100 also includes a plurality of ribs 111. The plurality of ribs 111 are all disposed on the outer peripheral wall of the body portion 110. Each rib 111 extends axially along the stator assembly 200. The plurality of ribs 111 are arranged at equal intervals along the circumference of the body portion 110. The circumference of the body portion 110, i.e., the direction in which the end plate 120 surrounds the body portion 110, is also the circumference of the stator assembly 200. The number of ribs 111 is equal to the number of winding slots 230, and the positions of the plurality of ribs 111 correspond one-to-one with the positions of the slot openings 231 of the plurality of winding slots 230. The plurality of ribs 111 are correspondingly inserted into the slot openings 231 of the plurality of winding slots 230. Therefore, the multiple ribs 111 can limit the stator assembly 200 in the circumferential direction, preventing the stator assembly 200 from rotating relative to the body portion 110 and improving the installation stability of the stator assembly 200. At the same time, it can increase the contact area between the shield 100 and the stator assembly 200, improving the bonding strength. When installing the stator assembly 200, after aligning the multiple ribs 111 with the slots 231 of the multiple winding grooves 230 respectively, the stator assembly 200 can be inserted into the body portion 110 along the axial direction, making assembly convenient.

[0057] Reference Figure 3 and Figure 4 As shown, it can be understood that, along the axial direction of the stator assembly 200, both ends of the winding 220 protrude from the two end faces of the stator core 210. For this purpose, the end plate 120 is provided with a groove 121, located on the side of the end plate 120 facing the stator assembly 200, with the opening of the groove 121 facing the stator assembly 200. The groove 121 is annular and arranged circumferentially along the body portion 110. The ends of the multiple windings 220 facing the end plate 120 are all accommodated within the groove 121. Therefore, the bonding strength between the stator assembly 200 and the shield 100 can be enhanced to a certain extent. Simultaneously, the axial height of the motor assembly in the stator assembly 200 can be shortened, reducing the installation space required for the motor assembly.

[0058] In addition, part of the structure of the molding compound 300 is filled in the groove 121. Specifically, part of the structure of the molding compound 300 is filled in the space between the groove wall of the groove 121 and the winding 220, which helps to enhance the bonding strength between the molding compound 300 and the stator assembly 200 and the shield 100, thereby improving the structural strength of the motor assembly.

[0059] In other embodiments, the groove 121 is composed of a plurality of arc-shaped recesses arranged at equal intervals along the direction surrounding the body portion 110. The inner contours of the plurality of arc-shaped recesses lie on the same circle, and the outer contours of the plurality of arc-shaped recesses lie on the same circle. The side closer to the central axis of the body portion 110 is the inner side, and the side farther from the central axis of the body portion 110 is the outer side. The number of arc-shaped recesses is equal to the number of windings 220. The ends of the plurality of windings 220 facing the end plate 120 are correspondingly accommodated in the plurality of arc-shaped recesses. Therefore, the bonding strength between the stator assembly 200 and the shield 100 can also be enhanced, and the axial height of the motor assembly in the stator assembly 200 can be shortened.

[0060] Reference Figure 2 and Figure 4 As shown, it can be understood that the groove wall of the groove 121 and the wall surface of the body part 110 away from the end plate 120 are both provided with multiple protrusions 130, and the multiple protrusions 130 at both locations are connected to the ribs 111. During injection molding of the encapsulated part 300, after the molten plastic is filled into the mold, the plastic comes into contact with the multiple protrusions 130, and the encapsulated part 300 is encapsulated in the multiple protrusions 130, that is, the protrusions 130 are embedded in the encapsulated part 300. Therefore, the contact area between the shield 100 and the encapsulated part 300 can be increased, thereby enhancing the bonding strength between the shield 100 and the encapsulated part 300, and thus improving the overall structural strength of the motor assembly, so that the encapsulated part 300 and the shield 100 can tightly wrap the stator assembly 200, improving the waterproof performance.

[0061] In other embodiments, only the groove wall of the groove 121 is provided with one or more protrusions 130, which are connected to the ribs 111. Therefore, the bonding strength between the shield 100 and the encapsulation 300 can be enhanced to a certain extent, thereby improving the overall structural strength of the motor assembly and improving the waterproof performance.

[0062] In other embodiments, one or more protrusions 130 are provided on the wall surface of the body portion 110 away from the end plate 120, and the protrusions 130 are connected to the ribs 111. Therefore, the bonding strength between the shield 100 and the molding compound 300 can be enhanced to a certain extent, thereby improving the overall structural strength of the motor assembly and improving the waterproof performance.

[0063] Reference Figure 1 and Figure 3As shown, it can be understood that, generally speaking, the stator assembly 200 also includes lead wires connected to the winding 220. The number of lead wires is typically three or four. These lead wires are used to electrically connect the winding 220 to an external circuit to supply power to the winding 220, enabling it to generate a magnetic field. To prevent the multiple lead wires from becoming tangled or disordered and affecting wiring, the motor assembly also includes a wire clamp 400. Multiple lead wires are fixed to the wire clamp 400. The wire clamp 400 can be a fixing structure used only to fix the relative positions of the multiple lead wires, or it can be a terminal block or connector, allowing the multiple lead wires to be arranged in a specific order, facilitating subsequent wiring to the external circuit and improving assembly efficiency.

[0064] Reference Figure 1 and Figure 3 As shown, it can be understood that the molding compound 300 covers at least a portion of the structure of the wire clip 400. Specifically, the molding compound 300 covers a portion of the structure of the wire clip 400, while another portion of the wire clip 400 protrudes from the outer wall of the molding compound 300, allowing the ends of multiple leads to be exposed on the outside of the molding compound 300, facilitating connection of the leads to external circuits. This allows the wire clip 400 to be fixed to the molding compound 300, ensuring a relatively fixed wiring position and facilitating wiring.

[0065] In other embodiments, when the outlet clamp 400 is a terminal block or connector, only the mating end of the terminal block or connector is exposed outside the plastic seal 300, while the rest of the terminal block or connector is encapsulated by the plastic seal 300, which can improve the installation stability of the outlet clamp 400.

[0066] Reference Figure 1 and Figure 3 As shown, it can be understood that the cable outlet clamp 400 is located on the outer side of the molding compound 300 along the radial direction of the stator assembly 200. Specifically, the cable outlet clamp 400 is located at the annular peripheral wall 320 of the molding compound 300, that is, a part of the structure of the cable outlet clamp 400 is embedded in the annular peripheral wall 320, and another part of the structure of the cable outlet clamp 400 protrudes from the outer wall surface of the annular peripheral wall 320. Therefore, wiring can be performed on the outer periphery of the motor assembly, which is convenient for operation. Furthermore, the protruding part of the cable outlet clamp 400 does not occupy the axial space of the motor assembly in the stator assembly 200, effectively reducing the axial height of the motor assembly in the stator assembly 200.

[0067] In other embodiments, provided there is sufficient installation space for the motor assembly, the cable clamp 400 may also be located at the end wall 310 of the molding compound 300, that is, a part of the structure of the cable clamp 400 is embedded in the end wall 310, and another part of the structure protrudes from the wall surface of the end wall 310 on the side away from the end plate 120.

[0068] Reference Figure 2 and Figure 3 As shown, the end plate 120 includes a plurality of first mounting ears 140 located on its outer periphery. The first mounting ears 140 protrude radially outward from the stator assembly 200, and the plurality of first mounting ears 140 are arranged at equal intervals along the circumferential direction of the stator assembly 200. Correspondingly, the molding compound 300 includes a plurality of second mounting ears 330 located on its outer periphery. Similarly, the second mounting ears 330 protrude radially outward from the stator assembly 200, and the plurality of second mounting ears 330 are arranged at equal intervals along the circumferential direction of the stator assembly 200. The number of second mounting ears 330 is equal to the number of first mounting ears 140, and the plurality of second mounting ears 330 and the plurality of first mounting ears 140 are arranged in a one-to-one correspondence along the axial direction of the stator assembly 200.

[0069] Reference Figure 2 and Figure 3 As shown, the first mounting ear 140 is provided with a first fixing hole 141, which penetrates two opposite end faces of the first mounting ear 140 along the axial direction of the stator assembly 200. That is, the end plate 120 is provided with a plurality of first fixing holes 141 arranged at equal intervals along the circumference of the stator assembly 200. Correspondingly, the second mounting ear 330 is provided with a second fixing hole 331, which penetrates two opposite end faces of the second mounting ear 330 along the axial direction of the stator assembly 200. That is, the molding compound 300 is provided with a plurality of second fixing holes 331 arranged at equal intervals along the circumference of the stator assembly 200. The plurality of second fixing holes 331 are respectively connected to the plurality of first fixing holes 141. Therefore, when installing the motor assembly to the water pump housing, it can be installed by fasteners such as screws or bolts passing through the first fixing holes 141 and the second fixing holes 331, facilitating the fixation of the motor assembly.

[0070] Reference Figure 2 As shown, it can be understood that in this embodiment, the number of the first mounting ear 140, the second mounting ear 330, the first fixing hole 141 and the second fixing hole 331 are all four. Of course, they can also be five, six or more.

[0071] Understandably, the magnetic ring 500 is configured as a sintered ferrite magnet. Sintered ferrite magnets have a dense internal structure and possess high permeability and saturation magnetization. On one hand, the magnetic properties of sintered ferrite are superior to those of plastic ferrite, enabling the surface magnetic flux density of the magnetic ring 500 to reach 1700 Gs to 2000 Gs. On the other hand, sintered ferrite has good corrosion resistance, allowing the magnetic ring 500 to adapt to working environments containing water without secondary protection, which helps reduce manufacturing costs.

[0072] It is easy to understand that the surface magnetic flux density of the magnetic ring 500 refers to the magnetic induction intensity at a certain point on the surface of the magnetic ring 500. The surface magnetic flux density is an important parameter for measuring the surface magnetic field strength of the magnetic ring 500. The surface magnetic flux density can be directly measured using a gaussmeter.

[0073] Reference Figure 5 As shown, it can be understood that the minimum inner diameter of the stator core 210 is defined as D1, and the maximum outer diameter of the magnetic ring 500 is defined as D3, satisfying: 0.04≤(D1-D3) / (2*D1)≤0.06.

[0074] It is understandable that, along the radial direction of the stator core 210, twice the shortest distance from the stator core 210 to its central axis is the minimum inner diameter D1 of the stator core 210.

[0075] Specifically, refer to Figure 5 An air gap 240 exists between the inner peripheral wall of the stator core 210 and the outer peripheral wall of the magnetic ring 500. The minimum width of the air gap 240 along the radial direction of the stator core 210 is defined as W. It can be understood that half the difference between the minimum inner diameter D1 of the stator core 210 and the maximum outer diameter D3 of the magnetic ring 500 is the minimum width W of the air gap 240 along the radial direction of the stator core 210, W = (D1 - D3) / 2. Further, (D1 - D3) / (2 * D1) = W / D1. Therefore, the relationship between the minimum inner diameter D1 of the stator core 210 and the maximum outer diameter D3 of the magnetic ring 500, (D1 - D3) / (2 * D1), is the ratio of the minimum width W of the air gap 240 to the minimum inner diameter D1 of the stator core 210.

[0076] In this embodiment, the ratio of the minimum width W of the air gap 240 to the minimum inner diameter D1 of the stator core 210 is between 0.04 and 0.06. For example, the ratio of the minimum width W of the air gap 240 to the minimum inner diameter D1 of the stator core 210 is 0.04, 0.05, or 0.06.

[0077] Understandably, when the minimum inner diameter D1 of the stator core 210 is constant, if the ratio of the minimum width W of the air gap 240 to the minimum inner diameter D1 of the stator core 210 is less than 0.04, the distance between the outer peripheral wall of the magnetic ring 500 and the inner peripheral wall of the stator core 210 will be too small. For water pump motors, a shielding sleeve 100 is installed between the magnetic ring 500 and the stator core 210. If the distance between the outer peripheral wall of the magnetic ring 500 and the inner peripheral wall of the stator core 210 is too small, friction between the shielding sleeve 100 and the magnetic ring 500 is likely to occur during rotation. Simultaneously, since water enters the gap between the magnetic ring 500 and the shielding sleeve 100 when the pump is working, impurities in the water can easily become stuck in this gap, potentially causing a blockage. When the minimum inner diameter D1 of the stator core 210 is constant, if the ratio of the minimum width W of the air gap 240 to the minimum inner diameter D1 of the stator core 210 is higher than 0.06, the distance between the outer peripheral wall of the magnetic ring 500 and the inner peripheral wall of the stator core 210 will be too large. This will result in a low magnetic flux density and high magnetic reluctance at the air gap 240, leading to a decrease in back electromotive force and consequently, a decline in the performance of the motor assembly. Therefore, the relationship between the minimum inner diameter D1 of the stator core 210 and the maximum outer diameter D3 of the magnetic ring 500 should satisfy: 0.04 ≤ (D1-D3) / (2*D1) ≤ 0.06. This ensures that the width of the air gap 240 along the radial direction of the stator core 210 is within a suitable range, preventing stalling and increasing magnetic flux density, thus guaranteeing good performance of the motor assembly.

[0078] Reference Figure 5 It is understandable that the minimum inner diameter of the stator core 210 is D1, and the maximum outer diameter of the stator core 210 is D2, satisfying: 1.6 ≤ D2 / D1 ≤ 2. It is also understandable that the ratio between the maximum outer diameter D2 and the minimum inner diameter D1 of the stator core 210 can be 1.6, 1.7, 1.8, 1.9, or 2.

[0079] Understandably, when the minimum inner diameter D1 of the stator core 210 is constant, if the ratio between the maximum outer diameter D2 and the minimum inner diameter D1 of the stator core 210 is less than 1.6, and the width of the yoke 211 is constant, the radial dimension of the winding slot 230 along the stator core 210 will be too small. A smaller area of ​​the winding slot 230 will lead to a lower slot fill factor, thus reducing the performance of the motor assembly. On the other hand, when the minimum inner diameter D1 of the stator core 210 is constant, if the ratio between the maximum outer diameter D2 and the minimum inner diameter D1 of the stator core 210 is greater than 2.0, the outer diameter of the motor will increase, which is detrimental to the installation of the motor assembly and increases material usage, thus raising costs. Therefore, when the ratio between the maximum outer diameter D2 of the stator core 210 and the minimum inner diameter D1 of the stator core 210 is 1.6 to 2, the stator core 210 can maintain a compact size while improving the slot fill factor, thereby enabling the motor assembly to meet performance requirements.

[0080] A second aspect of this utility model provides a water pump, including an impeller and a motor assembly as described in the first aspect of this utility model. The impeller is fixedly connected to a magnetic ring 500. For example, the magnetic ring 500 is fitted around the outer circumference of the shaft portion of the impeller, and the magnetic ring 500 and the shaft portion of the impeller are interference-fitted. Alternatively, the magnetic ring 500 and the impeller are injection molded as one piece. Therefore, after the winding 220 is powered, the impeller can be driven to rotate, thereby pumping water.

[0081] Since the water pump adopts all the technical solutions of the motor assembly in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0082] A third aspect of this utility model provides a water heater, including a water pump as described in the second aspect of this utility model. The water pump is used to pressurize water supply. The water heater here can be a gas water heater or an electric water heater, etc.

[0083] Since the water heater adopts all the technical solutions of the water pump in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0084] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A motor assembly, characterized in that, include: A shielding component includes a body and an end plate, the end plate being connected to one end of the body and arranged around the outer periphery of the body, the body having an inner cavity; The rotor assembly is rotatably disposed within the inner cavity; The stator assembly is ring-shaped and sleeved on the outside of the body portion, and is arranged around the rotor assembly; A molding compound covers the stator assembly and the body portion at the end opposite to the end plate, and the molding compound is connected to the end plate.

2. The motor assembly according to claim 1, characterized in that: Part of the structure of the molding compound fills the gap between the shield and the stator assembly.

3. The motor assembly according to claim 1, characterized in that: The shielding component is made of plastic or stainless steel.

4. The motor assembly according to claim 1, characterized in that: The shielding component also includes a plurality of ribs, which are connected to the outer peripheral wall of the body and are arranged at intervals along the circumference of the body. The stator assembly includes a plurality of winding slots, which are arranged at intervals along the circumference and have their openings facing the center of the stator assembly. The plurality of ribs are correspondingly inserted into the slot openings of the plurality of winding slots.

5. The motor assembly according to claim 1, characterized in that: The end plate has a groove on the side facing the stator assembly. The groove is arranged circumferentially along the body portion. The stator assembly includes a plurality of windings arranged sequentially along the circumferential direction. Partial structures of the plurality of windings are accommodated in the groove.

6. The motor assembly according to claim 5, characterized in that: The groove wall and / or the wall surface of the body portion away from the end plate are provided with protrusions, which are embedded in the plastic sealant.

7. The motor assembly according to claim 1, characterized in that: The motor assembly also includes a lead clamp, the stator assembly includes lead wires fixed to the lead clamp, and the molding compound further covers at least a portion of the structure of the lead clamp.

8. The motor assembly according to claim 7, characterized in that: The lead-out clamp is located on the outer side of the encapsulated part along the radial direction of the stator assembly.

9. The motor assembly according to claim 1, characterized in that: The end plate is provided with a plurality of first fixing holes, which are arranged at intervals along the circumference of the stator assembly. The molding compound is provided with a plurality of second fixing holes, which are correspondingly connected to the plurality of first fixing holes.

10. The motor assembly according to claim 1, characterized in that: The rotor assembly includes a magnetic ring, and the stator assembly includes a stator core. The stator core is arranged around the magnetic ring. The minimum inner diameter of the stator core is D1, and the maximum outer diameter of the magnetic ring is D3, satisfying: 0.04≤(D1-D3) / (2*D1)≤0.

06.

11. The motor assembly according to claim 1, characterized in that: The stator assembly includes a stator core, the minimum inner diameter of the stator core is D1, and the maximum outer diameter of the stator core is D2, satisfying: 1.6≤D2 / D1≤2.

12. The motor assembly according to claim 1, characterized in that: The rotor assembly includes a magnetic ring, which comprises multiple annular portions that are coaxial and sequentially spliced ​​along the axial direction of the rotor assembly.

13. A water pump, characterized in that, The assembly includes an impeller and a motor assembly as described in any one of claims 1 to 12, wherein the impeller is fixedly connected to the rotor assembly.

14. A water heater, characterized in that, Includes the water pump as described in claim 13.

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