Patent Publication Number: US-2020287439-A1

Title: Brushless motor and electronic products having the brushless motor

Description:
The present invention claims priority under 35 U.S.C. § 119 to Chinese Application No. 201910164330.7 filed on Mar. 5, 2019 the entire content of which is incorporated herein by reference. 
     BACKGROUND 
     Technical Field 
     The disclosure relates to the electromechanical field, and in particular, to a brushless motor and an electronic product having the brushless motor. 
     Description of Related Art 
     When a motor is used, it is generally required that a housing of the motor reaches a certain ingress protection rating, to prevent external miscellanies and water vapor from entering the motor to cause damage to internal components of the motor. 
     For an inner rotor motor, because a stator is disposed outside a rotor, the stator is stationary relative to a housing of the motor. Therefore, when manufactured, the housing of the inner rotor motor easily reaches a predetermined ingress protection rating. However, for an outer rotor motor, because a rotor is disposed outside a stator, the rotor rotates at a high speed relative to a housing of the motor. Therefore, when manufactured, it is not easy for the housing of the outer rotor motor to reach a predetermined ingress protection rating. 
     An outer rotor motor which has seal ring disposed in a gap between a cover body and a rotary shaft, to prevent external miscellanies and water vapor from entering the motor, is known. 
     It is found that, due to a small contact area between the sealing ring and an outer cover, the sealing ring is not easily fastened to the outer cover. When the rotary shaft rotates at a high speed, the sealing ring may easily fall off from the gap. Consequently, the motor is not sealed, and the service life of the motor is shortened. In addition, the sealing ring is in surface contact with the rotary shaft. Consequently, the friction between the sealing ring and the rotary shaft increases, and the sealing ring is easily worn, leading to a short service life. 
     It should be noted that the introduction in Background is merely provided for the convenience of clearly and comprehensively describing the technical solutions of the disclosure and facilitating the understanding of those skilled in the art. These technical solutions shall not be deemed well-known by those skilled in the art simply for having been described in Background. 
     SUMMARY 
     According to a first aspect of the embodiments of the disclosure, a brushless motor is provided. The brushless motor includes: a shaft, extending along a central axis; a stator part, disposed on a periphery of the shaft; a rotor part, disposed on a periphery of the stator part, arranged facing the stator part in a radial direction, and fastened to the shaft to rotate as the shaft rotates; a bearing part, disposed on a periphery of the shaft, and supporting the shaft in rotation; and a housing, receiving the stator part, the rotor part, and the bearing part, and including: an upper plate part located on an axial side of the rotor part, a tubular part extending in an axial direction from a radial outer side of the upper plate part, and a lower plate part located on an other axial side of the rotor part. An accommodating part is formed around the shaft on a radial inner side of the upper plate part, and a sealing component is arranged between the accommodating part and the shaft. 
     The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a brushless motor according to Embodiment 1 of the disclosure. 
         FIG. 2  is a schematic diagram of a sealing component viewed from an angle according to the disclosure. 
         FIG. 3  is a schematic diagram of the sealing component viewed from another angle according to the disclosure. 
         FIG. 4  is a schematic diagram of a cross section viewed in a B-B direction in  FIG. 3 . 
         FIG. 5( a )  to  FIG. 5( c )  are other schematic diagrams of the brushless motor according to Embodiment 1 of the disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     The foregoing and other features of the disclosure will become apparent from the following specification with reference to the accompanying drawings. Specific embodiments of the disclosure are disclosed in the specification and the accompanying drawings. The specification and the accompanying drawings describe several embodiments to which the principles of the disclosure are applicable. However, it should be understood that, the disclosure is not limited to the embodiments described herein, but shall include all modifications, variations and equivalents falling within the scope of the appended claims. 
     In the embodiments of the disclosure, terms such as “first”, “second”, “upper”, and “lower” are used for distinguishing different elements in name, but it does not indicate spatial arrangement or time sequence of these elements, and these elements should not be limited by these terms. The term “and/or” includes any one or all combinations of the one or more associated listed terms. Terms such as “contain”, “include”, and “comprise” refer to existence of the stated features, elements, parts, or components, but does not exclude existence or adding of one or more other features, elements, parts, or components. 
     In the embodiments of the disclosure, a singular form such as “a” or “an” includes a plural form. The singular form should be broadly understood as “a type” or “a class”, and rather than limited to the meaning “one”. In addition, the term “the” should be understood as including both a singular form and a plural form, unless otherwise specified in the context. In addition, the terms “according to” should be understood as “according to at least . . . ”, and the term “based on” should be understood as “based on at least . . . ”, unless otherwise specified in the context. 
     In addition, in the following description of the disclosure, for ease of description, a radius direction centered on a central axis of a shaft of a motor is referred to as a “radial direction”, a direction around the central axis is referred to as a “peripheral direction”, a direction along the central axis is referred to as an “axial direction” or an “extending direction of the axial direction”, a side away from the central axis in the radius direction is referred to as a “radial outer side”, and a side close to the central axis in the radius direction is referred to as a “radial inner side”. 
     Embodiment 1 of the disclosure provides a brushless motor.  FIG. 1  is a schematic diagram of the brushless motor according to Embodiment 1 of the disclosure.  FIG. 2  is a schematic diagram of a sealing component viewed from an angle according to the disclosure.  FIG. 3  is a schematic diagram of the sealing component viewed from another angle according to the disclosure.  FIG. 4  is a schematic diagram of a cross section viewed in a B-B direction in  FIG. 3 . 
     In the present embodiment, as shown in  FIG. 1 , a brushless motor  1  includes: a shaft  11 , a stator part  12 , a rotor part  13 , a bearing part  14 , and a housing  15 . The shaft  11  extends along a central axis C. The stator part  12  is disposed on the periphery of the shaft  11 . The rotor part  13  is disposed on the periphery of the stator part  12 , arranged facing the stator part  12  in a radial direction, and fastened to the shaft  11  to rotate as the shaft  11  rotates. The bearing part  14  is disposed on the periphery of the shaft  11 , and supports the shaft  11  in rotation. The housing  15  receives the stator part  12 , the rotor part  13 , and the bearing part  14 . 
     In the present embodiment, as shown in  FIG. 1 , the housing  15  includes: an upper plate part  151  located on an axial side of the rotor part  13 , a tubular part  152  extending in an axial direction from a radial outer side of the upper plate part  151 , and a lower plate part  153  located on the other axial side of the rotor part  13 . An accommodating part  1511  is formed around the shaft  11  on a radial inner side of the upper plate part  151 , and a sealing component  16  is arranged between the accommodating part  1511  and the shaft  11 . Therefore, the sealing component  16  is received in the accommodating part  1511 , which can prevent the sealing component  16  from falling off when the shaft  11  rotates at a high speed, thereby ensuring that the motor is sealed well, improving dust-proof and water-proof performance of the motor, and prolonging the service life of the motor. 
     In the present embodiment, as shown in  FIG. 1 , the accommodating part  1511  is a structure protruding along a direction away from the stator part  12  in the axial direction, but the disclosure is not limited thereto. The accommodating part  1511  may alternatively be a structure recessed along a direction close to the stator part  12  in the axial direction. As long as the sealing component  16  can be received, this is not limited in the disclosure. 
     In an implementation of the present embodiment, as shown in  FIG. 2  to  FIG. 4 , the sealing component  16  includes a body part  161  and at least two contact parts  162 , and the contact parts  162  extend from the body part  161  to a radial inner side. As shown in  FIG. 1 , the contact parts  162  are in contact with the shaft  11 , so that the shaft  11  is tightly clamped by using the contact parts  162 . Because the sealing component  16  is in contact with the shaft  11  by using only the contact parts  162 , a contact area between the sealing component  16  and the shaft  11  is small, so that the friction between the sealing component  16  and the shaft  11  is reduced, and the sealing component  16  is worn less. In addition, a lubricating oil may further be applied between the contact parts  162  and the shaft  11 , to improve the lubrication, and reduce the friction between the contact parts  162  and the shaft  11 . Therefore, the sealing component  16  is worn less, and the service life of the sealing component  16  is prolonged. 
     In the present embodiment, as shown in  FIG. 4 , a cross section of the contact parts  162  is in a claw shape, but the present embodiment is not limited thereto. The cross section of the contact parts  162  may alternatively be in other shapes, for example, a parallelogram or a rectangle, as long as the shaft  11  can be clamped. In addition, in the present embodiment, two contact parts  162  are taken as an example for description, but this is not limited in the present embodiment. There may alternatively be three or more contact parts  162 . In addition, extension lines of the two contact parts  162  in the present embodiment intersect in a direction extending to the body part  161 . An intersection angle is not limited in the present embodiment, which may be any angle between 0° and 180°. Alternatively, extension lines of a plurality of contact parts  162  may be parallel in the direction extending to the body part  161 . 
     In the present embodiment, the sealing component  16  is formed of an elastic material. The elastic material is, for example, rubber, an elastic nylon material, or silica gel, which is not limited in the present embodiment. The elastic material may further have specific hardness, to ensure wear resistance. The hardness ranges, for example, from 65 HA to 75 HA, and may alternatively be within other ranges, which is not limited in the present embodiment. 
     In the present embodiment, as shown in  FIG. 1 , the accommodating part  1511  and the shaft  11  are arranged with a gap G. Therefore, rigid contact between the housing  15  and the shaft  11  can be avoided, and a mechanical loss of the motor due to the friction between the housing  15  and the shaft  11  can also be avoided. In addition, a portion of the accommodating part  1511  nearest to the stator part  12  in the axial direction is closer to the stator part  12  than a portion of the sealing component  16  nearest to the stator part  12  in the axial direction. Therefore, the sealing component  16  is totally received in the accommodating part  1511 , and can be fastened reliably and hardly fall off, thereby ensuring that the motor is sealed well. 
     In the present embodiment, the accommodating part  1511 , the upper plate part  151 , and the tubular part  152  are integrally formed. Therefore, the housing can be formed through a simple process, thereby reducing manufacturing costs. In addition, the housing  15  is formed of a high-strength material, for example, steel. A strength range of the high-strength material is, for example, equal to or greater than 10 kgf/mm 2 . Therefore, crushing resistance of the housing  15  is ensured. 
       FIG. 5( a )  to  FIG. 5( c )  are other schematic diagrams of the brushless motor according to Embodiment 1 of the disclosure.  FIG. 5( a )  shows a status of the brushless motor viewed from an axial side of the brushless motor,  FIG. 5( c )  shows a status of the brushless motor viewed from the other side of the brushless motor, and  FIG. 5( b )  shows a status of the brushless motor viewed in the radial direction of the brushless motor.  FIG. 5( a )  and  FIG. 5( c )  are schematic diagrams, and  FIG. 5( b )  is a cross-sectional view. 
     In the present embodiment, as shown in  FIG. 5( a ) , the upper plate part  151  is provided with a plurality of through holes  1512 . A quantity of the through holes  1512  is four herein, and may alternatively be other quantities such as two or five, which is not limited in the disclosure. The plurality of through holes  1512  are formed by performing a stamping process on the upper plate part  151 . As shown in  FIG. 5( b ) , a portion, provided with the plurality of through holes  1512 , of the upper plate part  151  is recessed by a predetermined depth d along a direction close to the stator part  12  in the axial direction, and an inner wall of the through hole  1512  is provided with a thread. Therefore, an effective contact length of the through hole  1512  and a screw is increased by using the stamping process, and the upper plate part  151  is clamped more tightly. 
     In the present embodiment, as shown in  FIG. 1 , the tubular part  152  is provided with a positioning part  1521  recessed to a radial inner side. That is, a portion of the tubular part  152  is recessed to the radial inner side to form the positioning part  1521 . An axial side of the stator part  12  close to the lower plate part  153  is provided with a circuit board  17 . The positioning part  1521  is in contact with the circuit board  17 , to position the circuit board  17 . 
     In addition, the positioning part  1521  may not be disposed on the axial side of the tubular part  152  close to the lower plate part  153  as shown in  FIG. 1 . A location of the positioning part  1521  may be adjusted depending on a location of the circuit board  17 . For example, the circuit board  17  may be disposed on an axial side of the stator part  12  close to the upper plate part  151 . The positioning part  1521  may be disposed on an axial side of the tubular part  152  close to the upper plate part  151  and corresponding to the circuit board  17 , to position the circuit board  17 . 
     In the present embodiment, as shown in  FIG. 1 , the lower plate part  153  includes a folded part  1531  extending along a direction close to the stator part  12  in the axial direction on a radial outer side. A radial outer surface of the folded part  1531  is fastened to a radial inner surface of the tubular part  152 . Therefore, the sealing performance between the lower plate part  153  and the tubular part  152  is ensured. In addition, the circuit board  17  may further be in contact with the folded part  1531 . Therefore, the circuit board  17  is fastened by using both the positioning part  1521  and the folded part  1531 , to further ensure the stability of the circuit board  17 . 
     In the present embodiment, as shown in  FIG. 5( a )  and  FIG. 5( c ) , one side of the upper plate part  151  away from the stator part  12  is provided with a protection jig positioning part  1513 , one side of the lower plate part  153  away from the stator part  12  is provided with a positioning blind hole  1532 , and the upper plate part  151  and the lower plate part  153  are positioned and assembled by using the protection jig positioning part  1513  and the positioning blind hole  1532 . 
     In addition, in the present embodiment, as shown in  FIG. 5( c ) , the side of the lower plate part  153  away from the stator part  12  is provided with a wire connector  18 . Two wire connectors  18  are shown in  FIG. 5( c ) , but the present embodiment is not limited thereto. The quantity of the wire connectors may be one, three, or the like. The periphery of the wire connector  18  may further be provided with a sealing member such as a sealant (not shown in the figure). In addition, a central portion  1533  of the lower plate part  153  protrudes relative to a peripheral portion  1534  around the central portion  1533  in a direction away from the stator part  12 , and an edge of the central portion  1533  may also be provided with a sealing member (not shown in the figure). Therefore, the periphery of the housing is sealed by various sealing members, which improves dust-proof and water-proof effects of the motor, and improves an ingress protection rating of the motor. For example, the ingress protection rating of the motor is equal to or higher than IP51. 
     According to the embodiment of the disclosure, the sealing component is received in the accommodating part, which can prevent the sealing component from falling off when the shaft rotates at a high speed, thereby ensuring that the motor is sealed well, improving dust-proof and water-proof performance of the motor, and prolonging the service life of the motor. 
     Embodiment 2 of the disclosure provides an electronic product, which includes the brushless motor in Embodiment 1. As the structure of the brushless motor is described in detail in Embodiment 1, content thereof is incorporated herein and not described herein. 
     In the present embodiment, a structure of the electronic product is not limited, which may be household appliances such as an air conditioner, a water dispenser, a washing machine, a sweeper, a compressor, a blower, and a mixer, or may be electronic products in other fields. 
     According to the present embodiment, the sealing component is received in the accommodating part, which can prevent the sealing component from falling off when the shaft rotates at a high speed, thereby ensuring that the motor is sealed well, improving dust-proof and water-proof performance of the motor, prolonging the service life of the motor, and prolonging the service life of the electronic product. 
     Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises. While preferred embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.