Air gap control method for motor in low-voltage direct-current brushless water pump

Abstract

The invention discloses an air gap control method for a motor in a low-voltage direct-current brushless water pump, the motor is arranged in a bottom shell of the water pump, and the air gap control method comprises the steps that a motor stator and the bottom shell are subjected to injection molding in an integrated mold-out mode to form a bottom shell assembly; a plastic material with the thickness of 0.2-0.7 mm is used as a sealing isolation layer between the motor stator and the motor rotor, at least more than two positioning holes are uniformly distributed on the outer end face of the motor stator by taking the circle center as the center, and positioning pins which are respectively aligned with the front and rear directions of the positioning holes are arranged in an injection mold of the bottom shell. During injection molding, a positioning needle is inserted into the positioning hole for positioning, and the unilateral air gap between the plastic outer wall of the stator and the lower part of the rotor is controlled to be 0.5-1.2 mm. The air gap control method can save the product cost, improve the magnetic induction performance of the water pump motor and achieve the purpose of saving electric energy.

Description

Technical Field

[0001] The invention relates to the field of water pumps, in particular to the field of low-voltage direct current brushless water pumps. Background Art

[0002] The conventional structure of a low-voltage DC brushless water pump is that the bottom of the bottom shell is open, and a stator mounting frame is arranged on the upper part of the bottom shell. After the stator inside the bottom shell is installed, sealant is poured into the bottom shell, and then a bottom cover is added to the bottom of the bottom shell. According to this structural method, since the center of the stator needs a mounting frame, the aperture of the center of the stator will be larger, and the diameter of the rotor installed in the center hole of the stator will also be larger. Because the mounting frame is an independent part, the isolation gap between the rotor and the stator will also be larger, which will result in not only more production and processing steps, but also high cost. At the same time, due to the large air gap between the rotor and the stator, the magnetic induction rotation efficiency of the motor will decrease, increasing the energy consumption of the water pump. Summary of the invention

[0003] In order to solve the above problems, the present invention provides an air gap control method for a motor in a low-voltage DC brushless water pump, wherein the motor is arranged in a bottom shell of the water pump, and the air gap control method comprises: the motor stator and the bottom shell are injection molded in an integral manner to form a bottom shell assembly, the motor rotor is arranged in a first inner countersunk hole of the bottom shell assembly, a 0.2-0.7 mm thick plastic material is controlled between the motor stator and the motor rotor as a sealing isolation layer, and a rotating shaft is also passed through the center hole of the motor rotor. When the motor rotor rotates, it rotates around the rotating shaft.

[0004] Furthermore, the outer end surface of the motor stator is evenly distributed with at least two positioning holes centered on the center of the circle, and the injection mold of the bottom shell is provided with positioning pins aligned with the front and rear directions of the positioning holes respectively. When the front mold and the rear mold of the mold are closed, the positioning pins are inserted into the positioning holes on the motor stator to form positioning for the motor stator and the bottom shell during injection molding.

[0005] Furthermore, the single-sided air gap between the plastic outer wall of the stator and the lower part of the rotor is controlled to be 0.5-1.2 mm.

[0006] Furthermore, a boss is provided at the bottom of the first inner countersunk hole, and a mounting countersunk hole with an upper opening is provided at the center of the boss, and the first inner countersunk hole and the mounting countersunk hole have the same center.

[0007] Furthermore, a second inner countersunk hole with an opening at the bottom is arranged at the bottom center of the rotor, and the diameter and height of the second inner countersunk hole are greater than the diameter and height of the boss.

[0008] Furthermore, the bottom shell of the bottom shell assembly is made of plastic, preferably BMC plastic.

[0009] The working principle of the present invention is as follows: when the bottom shell and the stator of the water pump are formed into a bottom shell assembly by integral injection molding, the original stator mounting frame will be cancelled, and the aperture of the stator center for mounting the rotor can also be reduced. Because the plastic wall thickness outside the stator can be appropriately reduced by integral injection molding, the air gap between the rotor and the stator can also be reduced at the same time. The use of this process and method can greatly reduce product costs, while improving the magnetic induction performance of the water pump motor, thereby achieving the purpose of saving electric energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments of the present invention.

[0011] Figure 1 An exploded schematic diagram of the present invention is shown.

[0012] Figure 2 A schematic diagram of the finished product after assembly of the present invention is shown.

[0013] Figure 3 A cross-sectional view of the assembled present invention is shown.

[0014] Figure 4 An enlarged cross-sectional view of the present invention after assembly is shown. DETAILED DESCRIPTION

[0015] like Figure 1-Figure 4 As shown, the present invention is further described in detail by way of embodiments:

[0016] The present invention discloses an air gap control method for a motor in a low-voltage DC brushless water pump. In an implementation, the motor is arranged in a bottom shell of the water pump, and the air gap control method includes: a motor stator 2 and a bottom shell 1 are injection molded in an integral mold to form a bottom shell assembly, a motor rotor 4 is arranged in a first inner countersunk hole 104 of the bottom shell assembly, a plastic material with a thickness of T1=0.2-0.7mm is used as a sealing isolation layer 101 between the motor stator 2 and the motor rotor 4, a rotating shaft 3 is also passed through the center hole of the motor rotor 4, and two ends of the rotating shaft 3 are respectively installed at the center of the inner wall of the water pump cover and the bottom center of the first inner countersunk hole 104, and when the motor rotor 4 rotates, it rotates around the rotating shaft 3.

[0017] In this embodiment, at least two positioning holes 201 are evenly distributed on the outer end surface of the motor stator 2 with the center of the circle as the center. The injection mold of the bottom shell 1 is provided with positioning pins aligned with the positioning holes 201 in the front and rear directions respectively. When the front mold and the rear mold of the mold are closed, the positioning pins are inserted into the positioning holes 201 on the motor stator to form positioning for the motor stator 2 and the bottom shell 1 during injection molding.

[0018] In this embodiment, the air gap 5 between the plastic outer wall 101 of the motor stator 2 and the lower part of the motor rotor 4 is controlled to be T2=0.5-1.2mm. After the motor stator 2 is conductive, it rotates with the motor rotor 4 through the sealing isolation layer 101 by magnetic field induction. Since the plastic layer of the sealing isolation layer 101 is relatively thin and the space of the air gap 5 is also relatively small, the magnetic induction performance of the motor can be well improved and the power consumption can be reduced.

[0019] In this embodiment, a boss 102 is provided at the bottom of the first inner countersunk hole 104, and a mounting countersunk hole with an upper opening is provided at the center of the boss 102. The first inner countersunk hole 104 and the mounting countersunk hole have the same center, and the mounting countersunk hole is used to fix the lower end of the rotating shaft 3.

[0020] In this embodiment, a second inner countersunk hole 41 with an opening at the bottom is provided at the bottom center of the motor rotor 4. The diameter and height of the second inner countersunk hole 41 are greater than the diameter and height of the boss 102. When the motor rotor 4 rotates, it will not be blocked by the boss 102.

[0021] In this embodiment, the bottom shell 1 in the bottom shell assembly is made of plastic, preferably BMC plastic.

[0022] In this embodiment, the water pump upper cover and the bottom shell 1 are connected and fixed at the bracket position 103 with a screw structure. A hole is set in the center of the inner wall of the water pump upper cover for fixing the upper end of the rotating shaft 3. The structure of the water pump upper cover is conventional existing technology and will not be described in detail here.

[0023] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0025] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communicative with each other; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly limited.

[0026] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present invention. Those of ordinary skill in the art can change, modify, replace and modify the above embodiments within the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for controlling the air gap of a motor in a low-voltage DC brushless water pump, wherein the motor is arranged in a bottom shell of the water pump, characterized in that: The method comprises: a motor stator and a bottom shell are injection molded in an integral manner to form a bottom shell assembly, a motor rotor is arranged in a first inner countersunk hole of the bottom shell assembly, a 0.2-0.7 mm thick plastic material is used as a sealing isolation layer between the motor stator and the motor rotor, and a rotating shaft is also passed through the central hole of the motor rotor.

2. The air gap control method of a motor in a low-voltage DC brushless water pump according to claim 1, characterized in that: The outer end surface of the motor stator is evenly distributed with at least two positioning holes centered on the center of the circle. The injection mold of the bottom shell is provided with positioning pins aligned with the positioning holes in the front and rear directions respectively. When the front mold and the rear mold of the mold are closed, the positioning pins are inserted into the positioning holes on the motor stator to form positioning for the motor stator and the bottom shell during injection molding.

3. The air gap control method of a motor in a low-voltage DC brushless water pump according to claim 2, characterized in that: The single-sided air gap between the plastic outer wall of the stator and the lower part of the rotor is controlled to be 0.5-1.2 mm.

4. The air gap control method of a motor in a low-voltage DC brushless water pump according to claim 1, characterized in that: A boss is arranged at the bottom of the first inner countersunk hole, a mounting countersunk hole with an upper opening is arranged at the center of the boss, and the first inner countersunk hole and the mounting countersunk hole have the same center.

5. The air gap control method of a motor in a low-voltage DC brushless water pump according to claim 3, characterized in that: A second inner countersunk hole with an opening at the bottom is arranged at the center of the bottom of the rotor, and the diameter and height of the second inner countersunk hole are both greater than the diameter and height of the boss.

6. The air gap control method of a motor in a low-voltage DC brushless water pump according to claim 1, characterized in that: The bottom shell is made of plastic, preferably BMC plastic.

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