Patent Publication Number: US-11025127-B2

Title: Motor including an elastic mesh supporting a bearing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. application Ser. No. 15/698,884, filed on Sep. 8, 2017, which claims priority under 35 U.S.C. §§ 119 and 365 to Korean Patent Application No. 10-2016-0116747 filed on Sep. 9, 2016. The disclosures of the prior applications are incorporated by reference in their entirety. 
    
    
     FIELD 
     The present disclosure relates to a motor, and more particularly, to a motor including a bearing mounted to a rotating shaft of the motor. 
     BACKGROUND 
     A motor may be installed in a household appliance such as a vacuum cleaner. For example, a motor in a vacuum cleaner may generate a driving force for suctioning dust into a dust collecting part. 
     An example motor may include a motor housing, a stator installed in the motor housing, a rotor rotated by the stator, and a rotating shaft having the rotor mounted thereon. 
     In some examples, the rotating shaft of the motor may be supported by at least two bearings. The rotating shaft may be rotated at high speed while being supported by the at least two bearings. 
     In some cases, the at least two bearings may be mounted at different positions of the rotating shaft. The at least two bearings may support the rotating shaft at positions spaced apart from each other. 
     In some examples, a motor may be configured as an assembly of a plurality of parts, and an assembly tolerance may exist in the assembly. 
     A bearing provided in the motor may be installed in a state in which the bearing can be distorted due to the assembly tolerance. In this case, the amount of abrasion of the bearing may increase, and the lifespan of the bearing may be shortened. 
     SUMMARY 
     This disclosure describes implementations of a motor which can decrease abrasion of a bearing and increase the lifespan of the bearing. 
     According to one aspect of subject matter described in this application, a motor includes a motor housing, a rotating shaft assembly including a rotating shaft, a rotor, and a bearing in which the rotor and the bearing are mounted to the rotating shaft. The motor further includes a stator installed in the motor housing, the stator surrounding the rotor, a bracket mounted to the motor housing, and an elastic mesh that defines a plurality of pores, that is disposed between the bracket and the bearing, and that contacts at least one of the bracket or the bearing. 
     Implementations according to this aspect may include one or more of following features. The elastic mesh may include a metal wire mesh in which at least one metal wire has one or more curved portions. The elastic mesh may have a hollow cylindrical shape, and the plurality of pores may be open toward a radial direction of the elastic mesh. In some examples, a height of the elastic mesh may be greater than a height of the bearing. 
     In some implementations, the elastic mesh may include a mesh part that has a shape that is curled at least twice. In some cases, the mesh part may include an inner mesh part located at an innermost side in a radial direction, the inner mesh part contacting an outer circumferential surface of the bearing, and an outer mesh part located at an outermost side in the radial direction, the outer mesh part contacting the bracket. 
     In some implementations, the motor may further include a thermal conductive adhesive that fixes the elastic mesh to at least one of an outer circumferential surface of the bearing or the bracket. The motor may further include an O-ring that is fixed to the rotating shaft and located between the elastic mesh and the rotating shaft. The O-ring may support the bearing and have an external diameter less than an internal diameter of the elastic mesh. 
     In some implementations, the O-ring and the elastic mesh may define a gap between an outer circumference of the O-ring and the elastic mesh. The bearing may include an inner rim fixed to the rotating shaft, an outer rim spaced apart from the inner rim, and a rolling member disposed between the inner rim and the outer rim. The bracket may include an elastic mesh housing part that has an internal diameter greater than an external diameter of the outer rim, and the elastic mesh may be disposed between the outer rim and the elastic mesh housing part. 
     In some implementations, the motor may further include an O-ring that is mounted to the rotating shaft and that contacts the inner rim, the O-ring being spaced apart from the elastic mesh. The O-ring may include an inner ring contacting the inner rim, and an outer ring spaced apart from the outer rim. The outer ring may have an external diameter less than an internal diameter of the elastic mesh. 
     In some implementations, the bracket may further include a cover part that covers a portion of the bearing between the inner rim and the outer rim, and the elastic mesh may have a first end that contacts the cover part. In some examples, the elastic mesh may have a second end that is spaced apart from the rotor, the second end facing toward the rotor. The motor may further include a second bearing mounted to the rotating shaft, the motor housing may include a hollow part having an internal diameter greater than a diameter of the rotating shaft, and the hollow part may contact the second bearing to thereby support the second bearing. 
     In some implementations, the motor may further include a second bearing mounted to the rotating shaft, and a second elastic mesh defining a plurality of pores. The motor housing may include a hollow part that has an internal diameter greater than a diameter of the rotating shaft, and the second elastic mesh is disposed between an inner surface of the hollow part and an outer surface of the second bearing. 
     According to another aspect of subject matter described in this application, a motor includes a motor housing, a rotating shaft assembly including a rotating shaft, a rotor, and a bearing in which the rotor and the bearing are mounted to a rotating shaft. The motor further includes a stator installed in the motor housing, the stator surrounding the rotor, an impeller connected to the rotating shaft, an impeller cover that surrounds an outer circumference of the impeller in which the impeller cover defines an air inlet between the impeller and the impeller cover, a bracket mounted to at least one of the motor housing or the impeller cover, an elastic mesh that defines a plurality of pores, that is disposed between the bracket and the bearing, and that contacts at least one of the bracket or the bearing, and a diffuser mounted to at least one of the impeller cover or the bracket in which the diffuser includes a guide vane configured to guide air toward a space between the elastic mesh and the rotor. 
     Implementations according to this aspect may include one or more of following features. The bearing may include an inner rim fixed to the rotating shaft, an outer rim spaced apart from the inner rim, and a rolling member disposed between the inner rim and the outer rim. The bracket may include an elastic mesh housing part that has an internal diameter greater than an external diameter of the outer rim, and the elastic mesh may be disposed between the outer rim and the elastic mesh housing part. 
     In some implementations, the bracket may include a cover part that covers a portion of the bearing between the inner rim and the outer rim, and the elastic mesh has a first end that contacts the cover part. The elastic mesh may have a second end that is spaced apart from the rotor, the second end facing toward the rotor. In some examples, the motor may further include a second bearing mounted to the rotating shaft, and a second elastic mesh defining a plurality of pores. The motor housing may include a hollow part that has an internal diameter greater than a diameter of the rotating shaft, the second bearing may have an external diameter less than the internal diameter of the hollow part, and the second elastic mesh may be disposed between an inner surface of the hollow part and an outer surface of the second bearing. 
     According to the present disclosure, the plurality of pores formed in the elastic mesh can efficiently dissipate heat transferred from the bearing while assisting the elastic mesh to be smoothly elastically deformed. In some implementations, the elastic mesh having the plurality of pores can generate a damping effect, thereby absorbing external impact. Thus, it may be possible to highly reduce noise and vibration and to improve the reliability of the motor. 
     In some implementations, the metal wire mesh having the plurality of pores has a high elastic deformation rate, and can maintain the alignment of the bearing, In some implementations to heat dissipation. 
     In some implementations, when the concentricities of the bearing and the second bearing spaced apart from each other do not correspond to each other due to an assembly tolerance, the elastic mesh elastically deformed by the bearing can align the position of the bearing, and the concentricities of the bearing and second bearing can correspond to each other through a simple structure of the elastic mesh. 
     In some implementations, the elastic mesh aligns the position of the bearing, and the second elastic mesh aligns the position of the second bearing, so that the position of each of the bearing and the second bearing can be optimally aligned. 
     In some implementations, air guided by the guide vane of the diffuser is flowed into the elastic mesh, so that heat transferred from the bearing to the elastic mesh can be efficiently dissipated. 
     The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view showing an example motor. 
         FIG. 2  is an exploded perspective view showing the example motor. 
         FIG. 3  is an enlarged sectional view of portion A of  FIG. 1 . 
         FIG. 4  is a cross-sectional view showing an example elastic mesh elastically deformed by an example bearing. 
         FIG. 5  is a graph showing an example lifespan of example bearings with respect to their concentricity errors. 
         FIG. 6  is a sectional view showing another example of the elastic mesh shown in  FIG. 4 . 
         FIG. 7  is a sectional view showing still another example of the elastic mesh shown in  FIG. 4 . 
         FIG. 8  is a sectional view showing another example motor. 
         FIG. 9  is an enlarged sectional view of portion B of  FIG. 8 . 
         FIG. 10  is a cross-sectional view showing an example second elastic mesh elastically deformed by an example second bearing. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary implementations of the present disclosure will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a sectional view showing an example motor.  FIG. 2  is an exploded perspective view showing the example motor.  FIG. 3  is an enlarged sectional view of portion A of  FIG. 1 .  FIG. 4  is a cross-sectional view when an example elastic mesh is elastically deformed by an example bearing. 
     The example motor M includes a motor housing  1 , a rotating shaft assembly R, a stator  2 , a bracket  8 , and an elastic mesh  9 . 
     The motor housing  1  may form an external appearance of the motor M. The motor housing  1  may have a hollow cylindrical shape having one open surface. An air outlet  11  through which air inside the motor housing  1  is discharged to the outside may be formed in the motor housing  1 . A plurality of air outlets  11  may be formed in the motor housing  1 . 
     The rotating shaft assembly R may include a rotating shaft  3 , and a rotor  4  and a bearing  5 , which are mounted to the rotating shaft  3 . 
     The stator  2  may be installed in the motor housing  1 . The stator  2  may be mounted to the motor housing  1  using a fastening member such as a screw. 
     The stator  2  may be formed in a hollow cylindrical shape. The stator  2  may be installed to surround the outer circumference of the rotor  4 . 
     The stator  2  may be configured as an assembly of a plurality of members. The stator  2  may include a stator core  21 , a pair of insulators  22  and  23  coupled to the stator core  21 , and a coil  24  disposed at the insulators  22  and  23 . 
     The rotating shaft  3  is rotated together with the rotor  4 , and may be supported by a bearing  5 . The rotating shaft  3  may be rotated by the rotor  4 . 
     A portion of the rotating shaft  3  may be located inside the motor housing  1 , and the rest of the rotating shaft  3  may be located inside an impeller cover  73  which will be described later. The rotating shaft  3  may be disposed long from the inside of the motor housing  1  to the inside of the impeller cover  73 . 
     In some implementations, an example impeller connection part  32  to which an impeller  71  is connected may be formed at the rotating shaft  3 . The impeller connection part  32  may be formed at a position spaced apart from a part  31  surrounded by the rotor  4 . The impeller connection part  32  may be formed at an end portion of the rotating shaft  3 . 
     A second bearing mounting part at which a second bearing  6  which will be described later is mounted may be formed at the rotating shaft  3 . 
     The rotor  4  may be mounted to surround a portion of the rotating shaft  3 . The rotor  4  may be rotatably located inside the stator  2 . The rotor  4  may be formed in a hollow cylindrical shape. 
     The rotor  4  may include an iron core  41  fixed to the rotating shaft  3 , a magnet  42  installed at the iron core  41 , and a pair of end plates  43  and  44  that fix the magnet  42 . 
     The rotor  4  may be mounted to surround the part  31  between one end and the other end of the rotating shaft  3 . The rotor  4  may be mounted between the impeller connection part  32  and the bearing mounting part. 
     The bearing  5  may include an inner rim  51  fixed to the rotating shaft  3 , an outer rim  52  spaced apart from the inner rim  51 , and a rolling member  53  disposed between the inner rim  51  and the outer rim  52 . 
     The bearing  5  may be one of a roller bearing and a ball bearing. The bearing  5  may be configured as a ball bearing in which the rolling member  53  is configured as a ball to have high performance in high-speed rotation. 
     In some implementations, the motor M may further include an O-ring  54  that is fixed to the rotating shaft  3  and that supports bearing  5 . 
     The O-ring  54  may be fixed to the rotating shaft  3 , and may be included in a rotating shaft assembly or in a rotor assembly together with the rotating shaft  3  and the rotor  4 . 
     The O-ring  54  may be located between the bearing  5  and the rotor  4  in the length direction of the rotating shaft  3 . The O-ring  54  may restrict the bearing  5  from moving toward the rotor  4 . The O-ring  54  may serve as a bearing stopper supporting the bearing  5 . 
     The O-ring  54  may be fixed to the rotating shaft  3  to come in contact with a portion of the bearing  5 . At least one portion of the O-ring  54  may face the inner rim  51  of the bearing  5 . The O-ring  54  may come in contact with the inner rim  51  of the bearing  5 . The O-ring  54  may be a bearing stopper that restricts the inner rim  51  of the bearing  5  from sliding toward the rotor  4 . 
     The external diameter D 1  of the O-ring  54  may be smaller than the internal diameter D 2  of the elastic mesh  9 . 
     The O-ring  54  may be located inside the elastic mesh  9 . When the rotating shaft  3  rotates, the O-ring  54  may be rotated in an empty space formed inside the elastic mesh  9 . 
     A gap G 1  may be formed between the outer circumference of the O-ring  54  and the elastic mesh  9 , and the O-ring  54  and the elastic mesh  9  may not come in contact with each other. If the O-ring  54  and the elastic mesh  9  come in contact with each other, at least one of the O-ring  54  and the elastic mesh  9  may be abraded. On the other hand, if the O-ring  54  and the elastic mesh  9  do not come in contact with each other, the lifespan of each of the O-ring  54  and the elastic mesh  9  can be maximized. 
     The O-ring  54  may be mounted to the rotating shaft  3 , come in contact with the inner rim  51  of the bearing  5 , and be spaced apart from the elastic mesh  9 . 
     The O-ring  54  may include an inner ring  55  coming in contact with the inner rim  51  and an outer ring  56  spaced apart from the outer rim  52 . The outer circumference of the outer ring may be the outer circumference of the O-ring  54 , and the external diameter of the outer ring  56  may be the external diameter D 1  of the O-ring  54 . 
     In the motor M, a portion of the rotating shaft  3 , which is located inside the motor housing  1 , may be directly supported by the motor housing  1 . 
     When the rotating shaft  3  is directly supported by the motor housing  1 , a rotating shaft support part rotatably supporting the rotating shaft  3  may be formed in the motor housing  1 . The rotating shaft support part may be formed in the motor housing  1  to surround the outer circumference of the rotating shaft  3 . A lubrication medium for preventing abrasion between the rotating shaft  3  and the rotating shaft support part, such as a lubricant, may be provided to at least one of the rotating shaft  3  and the rotating shaft support part. 
     In some implementations, in the motor M, the portion of the rotating shaft  3 , which is located inside the motor housing  1 , may be supported through the second bearing  6 . The motor M may further include the second bearing  6  mounted to the rotating shaft  3 , and the second bearing  6  may rotatably support the rotating shaft  3 . 
     The second bearing  6  may be mounted to the rotating shaft  3  to be spaced apart from the bearing  5 . The second bearing  6  may be spaced apart from the bearing  5  in the length direction of the rotating shaft  3 . 
     The bearing  5  and the second bearing  6  may rotatably support the rotating shaft  3  at positions spaced apart from each other. In this case, the weight of the rotating shaft  3  may be distributed by the bearing  5  and the second bearing  6 . 
     In the motor M, the bearing  5  and the second bearing  6  may be mounted together between the rotor  4  and the impeller  71 . In this case, the bearing  5  and the second bearing  6  may be mounted at a position between the rotor  4  and the impeller  71  to be spaced apart from each other in the axial direction of the rotating shaft  3 . 
     In some implementations, in the motor M, the bearing  5  and the second bearing  6  may be mounted to be spaced apart from each other with the rotor  4  interposed therebetween. In this case, the bearing  5  and the second bearing  6  may support the rotating shaft  3  by efficiently distributing the weight of the rotating shaft  3 . When the bearing  5  and the second bearing  6  are arranged with the rotor  4  interposed therebetween, the maximum weight applied to the bearing  5  and the second bearing  6  is lower than that when the bearing  5  and the second bearing  6  are mounted together between the rotor  4  and the impeller  71 , and the lifespan of each of the bearing  5  and the second bearing  6  is longer than that when the bearing  5  and the second bearing  6  are mounted together between the rotor  4  and the impeller  71 . In some implementations, when the bearing  5  and the second bearing  6  are arranged with the rotor  4  interposed therebetween, a separate space for allowing the bearing  5  and the second bearing  6  to be spaced apart from each other is not required, and the motor M can be compact as compared with when the bearing  5  and the second bearing  6  are mounted together between the rotor  4  and the impeller  71 . 
     The second bearing  6  may be located between the rotating shaft  3  and the motor housing  1  to support the rotating shaft  3 . In this case, the second bearing  6  may be spaced apart from the bearing  5  with the rotor  4  interposed therebetween. 
     In some cases, when the motor M includes both of the bearing  5  and the second bearing  6 , the bearing  5  may be a load-side bearing close to the impeller  71 , and the second bearing  6  may be a non-load-side bearing distant from the impeller  71 , or vice versa. 
     In some implementations, when the motor M includes both of the bearing  5  and the second bearing  6 , the bearing  5  may be a bracket-side bearing surrounded by the bracket  8 , and the second bearing  6  may be a motor housing-side bearing surrounded by motor housing  1 . 
     The bearing  5  may be a first bearing mounted between the impeller  71  and the second bearing  6 , for example, or between the impeller  71  and the rotor  4 , and the second bearing  6  may be an end bearing mounted at an end portion of the rotating shaft  3 , which is opposite to the impeller  71 . 
     When the rotating shaft  3  is supported by the second bearing  6 , the second bearing  6  may be mounted to the rotating shaft  3  to be located inside the motor housing  1 . A hollow part  12  larger than the rotating shaft  3  may be formed in the motor housing  14 . The hollow part  12  may be formed larger than the second bearing  6 . The second bearing  6  may be directly supported by the motor housing  1 , or may be supported by the motor housing  1  with a separate elastic member interposed therebetween. 
     When the second bearing  6  is directly supported by the motor housing  1 , the outer circumferential surface of the second bearing  6  may come in contact with the hollow part  12  to be supported by the hollow part  12 . 
     The second bearing  6  may include an inner rim  61  fixed to the rotating shaft  3 , an outer rim  62  spaced apart from the inner rim  61 , and a rolling member  63  disposed between the inner rim  61  and the outer rim  62 . 
     In some implementations, the second bearing  6  may be one of a roller bearing and a ball bearing. The second bearing  6  may be configured as a ball bearing in which the rolling member  63  is configured as a ball to have high performance in high-speed rotation. 
     The inner rim  61  of the second bearing  6  may be fixed to the rotating shaft  3 , and the outer rim  62  of the second bearing  6  may come in contact with the hollow part  12  to be fixed to the hollow part  12 . 
     The motor M may further include a second O-ring  64  fixed to the rotating shaft  3 , the second O-ring  64  supporting the second bearing  6 . The second O-ring  64  may be fixed to the rotating shaft  3 , and may be included in a rotating shaft assembly or in a rotor assembly together with the rotating shaft  3  and the rotor  4 . 
     The second O-ring  64  may be located between the second bearing  6  and the rotor  4  in the length direction of the rotating shaft  3 . The second O-ring  64  may restrict the second bearing  6  from moving toward the rotor  4 . The second O-ring  64  may serve as a bearing stopper supporting the second bearing  6 . 
     The second O-ring  64  may be fixed to the rotating shaft  3  to come in contact with a portion of the second bearing  6 . At least one portion of the second O-ring  64  may face the inner rim  61  of the second bearing  6 . The second O-ring  64  may come in contact with the inner rim  61  of the second bearing  6 . The second O-ring  64  may be a bearing stopper that restricts the inner rim  61  of the second bearing  6  from sliding toward the rotor  4 . 
     The second O-ring  64  may be mounted to the rotating shaft  3 , come in contact with the inner rim  61  of the second bearing  6 , and be spaced apart from the hollow part  12 . 
     The second O-ring  64  may include an inner ring  65  coming in contact with the inner rim  61  of the second bearing  6  and an outer ring  66  spaced apart from the outer rim  62  of the second bearing  6 . 
     In some implementations, the motor M may further include the impeller  71  connected to the rotating shaft  3 , and the impeller cover  73  surrounding the outer circumference of the impeller  71 , the impeller cover  73  having an air inlet  72  formed therein. 
     The impeller  71  may be rotated together with the rotating shaft  3  in the state in which the impeller  71  is connected to the rotating shaft  3 . The impeller  71  may be located between the impeller cover  73  and a diffuser  74  which will be described later. 
     The impeller cover  73  may protect the impeller  71  by surrounding the outer circumference of the impeller  71 . 
     A surface of the impeller cover  73  may open toward the motor housing  1 . The impeller cover  73  may be disposed to cover one open surface of the motor housing  1 . The impeller cover  73  may be coupled to the motor housing  1  or the bracket  8  using a fastening member such as a screw, for example, or may be screw-coupled to the motor housing  1  or the bracket  8 . 
     The air inlet  72  may be formed smaller than the surface of the impeller cover  73 , which is opposite to the motor housing  1 . 
     The inner circumferential surface of the impeller cover  73  may be spaced apart from the impeller  7 , and air flowed by the impeller  71  may be flowed between the inner circumference of the impeller cover  73  and the impeller  71 . 
     In some implementations, the motor M may further include the diffuser  74  located inside the impeller cover  73 . The diffuser  74  may be mounted to at least one of the impeller cover  73  and the bracket  8 . 
     The diffuser  74  may include a body part  75  having a smaller size than the impeller cover  73 , a diffuser vane  76  protruding from the outer circumference of the body part  75 , and a guide vane  77  guiding air flowed by the diffuser vane  76 . 
     The diffuser vane  76  may be formed to change the dynamic pressure of air passing through the impeller  71  to static pressure. 
     The guide vane  77  may be formed to guide air of which pressure is increased by the diffuser vane  76  to at least one of the elastic mesh  9  and the rotor  4 . 
     The guide vane  77  may guide air toward between the elastic mesh  9  and the rotor  4 . A portion of the air guided by the guide vane  77  may be flowed into the elastic mesh  9  to dissipate heat of the elastic mesh  9 . 
     The bracket  8  may be mounted to at least one of the motor housing  1  and the impeller cover  73 . 
     In some examples, an elastic mesh housing part  81  of which internal diameter is greater than the external diameter of the outer rim  52  of the bearing  5  may be formed at the bracket  8 . A gap in which the elastic mesh  9  can be accommodated may be formed between the outer rim  52  of the bearing  5  and the elastic mesh housing part  81 . 
     The elastic mesh housing part  81  may be formed larger than the O-ring  54 , and the internal diameter of the elastic mesh housing part  81  of the bracket  8  may be greater than the external diameter of the O-ring  54 . The O-ring  54  may be rotated in a space formed inside the elastic mesh housing part  81 . A gap may be formed between the inner circumferential surface of the elastic mesh housing part  81  of the bracket  8  and the outer circumference of the O-ring  54 . The gap may be larger than the thickness of the elastic mesh  9 . 
     The bracket  8  may include a cover part  82  covering between the inner rim  51  and the outer rim  52 . The cover part  82  may be formed in a shape bent from the elastic mesh housing part  81 . The cover part  82  may be formed in a ring shape at one end of the elastic mesh housing part  81 . A rotating shaft through-hole  83  through which the rotating shaft  3  rotatably passes may be formed in the cover part  82 . The diameter D 3  of the rotating shaft through-hole  83  may be smaller than the internal diameter D 2  of the elastic mesh  9 . 
     The cover part  82  may be spaced apart from the O-ring  54 , and a bearing accommodation space S 1  in which the bearing  5  is accommodated may be formed between a surface of the O-ring  54  facing the bearing  5  and a surface of the cover part  82  facing the bearing  5 . 
     The bracket  8  may include a fastening part  84  fastened to at least one of the motor housing  1  and the impeller cover  73 . The fastening part  84  may be formed in a ring shape. The fastening part  84  may be fastened to at least one of the motor housing  1  and the impeller cover  73  using a fastening member  85  such as a screw. The fastening part  84  may be formed larger than the elastic mesh housing part  81 . The bracket  8  may include at least one connection part  86  connecting the fastening member  85  and the elastic mesh housing part  81 . 
     In some implementations, the bearing  5  and the second bearing  6  may be mounted such that their center axes correspond to each other. When the center axes of the bearing  5  and the second bearing  6  do not correspond to each other, the abrasion of any one of the bearing  5  and the second bearing  6  may be large. 
     In the motor M, the center axis H 1  of the elastic mesh housing part  81  and the center axis of the hollow part  12  may not correspond to each other due to an assembly tolerance of the motor housing  1  and the bracket  8 . For example, when the bearing and the second bearing  6  are mounted with the rotor  4  interposed therebetween, a concentricity error between the bearing  5  and the second bearing  6  may be increased. 
     Although the center axis H 1  of the elastic mesh housing part  81  and the center axis of the hollow part  12  do not correspond to each other, the elastic mesh  9  may adjust the position of the bearing  5  to be aligned with the position of the second bearing  6  such that the center axis B 1  of the bearing  5  and the center axis of the second bearing  6  closely correspond to each other. 
     The elastic mesh  9  may be disposed between the bracket  8  and the bearing  5 , and may support bearing  5 . The elastic mesh  9  may be press-fitted between the bracket  8  and the bearing  5 . 
     In some implementations, in the motor M, the concentricities of the bearing  5  and the second bearing  6  may not correspond to each other due to the assembly tolerance of the motor housing  1  and the bracket  8 . When the concentricities of the bearing  5  and the second bearing  6  may not correspond to each other as described above, the elastic mesh  9  may support the bearing  5  such that the concentricity of the bearing  5  corresponds to that of the second bearing  6  in a state in which a portion of the elastic mesh  9  is elastically compressed. 
     The bearing  5 , as shown in  FIG. 4 , may pressurize a portion of the elastic mesh  9  in case the center axis B 1  of the bearing  5  and the center axis H 1  of the elastic mesh housing part  81  do not correspond to each other. In this case, the elastic mesh  9  may support the bearing  5  in the state in which the portion pressurized by the bearing  5  is compressed. 
     The elastic mesh  9  may be formed in a structure in which the elastic mesh  9  can be easily elastically deformed, and heat transferred from the bearing  5  can be easily dissipated. 
     A plurality of pores S 2  and S 3  may be formed in the elastic mesh  9 . The elastic mesh  9  may be disposed between the bracket  8  and the bearing  5  to come in contact with at least one of the bracket  8  and the bearing  5 . 
     The elastic mesh  9  may have a hollow cylindrical shape. A cylindrical empty space may be formed inside the elastic mesh  9 . 
     The elastic mesh  9  may be disposed between the outer rim  52  and the elastic mesh housing part  81 . 
     The height L 1  may be greater than the height L 2  of the bearing  5 . A portion of the elastic mesh  9  may be disposed between the outer rim  52  and the elastic mesh housing part  81 . The internal diameter of the elastic mesh  9  may be equal to or smaller than the external diameter of the outer rim  52 . In some implementations, the external diameter of the elastic mesh  9  may be equal to or smaller than the internal diameter of the elastic mesh housing part  81 . A portion of the elastic mesh  9  may be press-fitted between the outer rim  52  and the elastic mesh housing part  81 , and may be fixed between the elastic mesh housing part  81  and the outer rim  52  in the state in which the portion of the elastic mesh  9  is press-fitted. 
     In some implementations, the internal diameter D 2  of the elastic mesh  9  may be greater than the external diameter D 1  of the outer ring  56 . 
     The elastic mesh  9  may include a first area  9 A that faces the bearing  5  and a second area  9 B that does not face the bearing  5 . 
     The first area  9 A of the elastic mesh  9  may face the bearing accommodation space S 1 . The second area  9 B of the elastic mesh  9  may include an area that faces the O-ring  54 . The second area  9 B of the elastic mesh  9  may further include an area that does not face both of the bearing accommodation space S 1  and the O-ring  54 . 
     The elastic mesh  9  may have one end  94  spaced apart from the impeller  71  and the diffuser  74 , the one end  94  facing the cover part  82 . The one end o 4  of the elastic mesh  9  may come in contact with the cover part  82 . When the one end  94  of the elastic mesh  9  comes in contact with the cover part  82 , the one end  94  of the elastic mesh  9  may be held by the cover part  82 , and the mounting position of the elastic mesh  9  may be determined by the cover part  82 . 
     In some implementations, the elastic mesh  9  may be protected by the elastic mesh housing part  81 , the cover part  82 , and the outer rim  52 . 
     In some implementations, the elastic mesh  9  may have the other end  95  spaced apart from the rotor  4 , the other end  95  facing the rotor  4 . The other end of the elastic mesh  9  may be located at the outside of the bearing accommodation space S 1 . 
     The elastic mesh  9  may include a metal wire mesh in which at least one metal wire  91  is irregularly tangled. 
     Heat of the bearing  5  may be transferred to the metal wire  91 , and the heat transferred to the metal wire  91  may be transferred to the bracket  8  through a bracket contact part  92  of the metal wire  91 , which comes in contact with the bracket  8 . 
     In some implementations, the heat transferred to the metal wire  91  may be dissipated in an air cooling manner through the second area  9 B of the metal wire  91 , which does not face the bearing  5 . 
     For example, the heat of the bearing  5  may be transferred to the bracket  8  through the elastic mesh  9 , and the heat transferred to the bracket  8  may be transferred to air in the motor M through the elastic mesh  9 . 
     The plurality of pores S 2  and S 3  may be open in the radial direction of the elastic mesh  9 . The plurality of pores S 2  and S 3  may include at least one first pore S 2  that faces the outer rim  52  of the bearing  5  and at least one second pore S 3  that does not face the outer rim  52  of the bearing  5 . 
     The second pore S 3  may be located at the outside of the bearing accommodation space S 1 , and the air guided by the diffuser  74  may be introduced into the elastic mesh  9  through the second pore S 3 . 
     Hereinafter, an example of heat dissipation of the bearing will be described in detail as follows. 
     In the motor M, when the rotating shaft  3  rotates, the impeller  71  may be rotated, and air may be suctioned into the impeller  71  through the air inlet  72 . 
     The air suctioned into the impeller  71  may be flowed into the diffuser  74 , and the air flowed into the diffuser  74  may be sequentially guided by the diffuser vane  76  and the guide vane  77 . 
     The air guided by the guide vane  77  may be flowed toward between the elastic mesh  9  and the rotor  4 , and a portion of the air may be flowed into the elastic mesh  9  to be introduced into the plurality of pores S 2  and S 3  of the elastic mesh  9 . 
     A process in which air is introduced into the elastic mesh  9  will be described in detail. The air may be introduced into the elastic mesh  9  through the second pore S 3  of the elastic mesh  9 , which is located at the outside of the bearing accommodation space S 1 , and at least a portion of the air may be guided to the outer rim  52  of the bearing  5  and the elastic mesh housing part  81  to be flowed into the first pore S 2 . For example, the air may be introduced into not only the second pore S 3  of the elastic mesh  9  but also the first pore S 2  of the elastic mesh  9 . 
     The air introduced into the plurality of pores S 2  and S 3  of the elastic mesh  9  may come in contact with each of the bearing  5 , the elastic mesh  9 , and the elastic mesh housing part  81  between the outer circumferential surface of the bearing  5  and the elastic mesh housing part  81 , and may absorb heat of each of the bearing  5 , the elastic mesh  9 , and the elastic mesh housing part  81 . 
       FIG. 5  is a graph showing an example lifespan of each bearing with respect to its concentricity error between the bearings. 
       FIG. 5  is, for example, a graph showing an example lifespan of each bearing with respect to its concentricity error between the bearing  5  and the second bearing  6 , shown in  FIG. 1 . When the concentricity error between the bearing  5  and the second bearing  6  is 0.05 mm or less, the lifespan of each bearing can be highly maintained. When the concentricity error between the bearing  5  and the second bearing  6  is 0.05 mm or more, the lifespan of each bearing is rapidly decreased as shown in  FIG. 5 . 
     For example, the concentricity error between the bearing  5  and the second bearing  6  may be maintained to be 0.05 mm or less. In this example, although the center axis of the bearing  5  and the center axis of the second bearing  6  do not correspond to each other, the elastic mesh  9  elastically deformed by the bearing  5  can maintain the center axis of the bearing  5  and the center axis of the second bearing  6  to have an error of 0.05 mm or less, and thus the lifespan of each of the bearing  5  and the second bearing  6  can be maximized. 
       FIG. 6  is a sectional view showing another example of the elastic mesh shown in  FIG. 4 . 
     The motor M may include a thermal conductive adhesive  96  that may fix the elastic mesh  9  to at least one of the outer circumferential surface of the bearing  5  and the bracket  8 . 
     For example, the thermal conductive adhesive  96  may be located between the outer rim  52  of the bearing  5  and the elastic mesh housing part  81  of the bracket  8 . 
     The thermal conductive adhesive  96  may restrict the elastic mesh  9  from being arbitrarily separated between the outer rim  52  of the bearing  5  and the elastic mesh housing part  81  of the bracket  8 . 
     The thermal conductive adhesive  96  may be formed at a plurality of portions between the outer rim  52  of the bearing  5  and the elastic mesh housing part  81  of the bracket  8 . 
     Air introduced into the elastic mesh  9  may be diffused into the elastic mesh  9  while passing between the thermal conductive adhesives  96 . 
       FIG. 7  is a sectional view showing still another example of the elastic mesh shown in  FIG. 4 . 
     An elastic mesh  9 ′ may have a shape in which a mesh part having a plurality of pores formed therein is curled at least twice. 
     In some implementations, the elastic mesh  9 ′ may be manufactured by curling, plural times, a strip-shaped mesh part in a scroll form. The strip-shaped mesh part may be formed of a metal having a high heat transfer performance. The strip-shaped mesh part may be configured such that a plurality of metal wires are irregularly coupled, or may be configured such that a plurality of metal wires are arranged in a regular pattern such as a grid pattern. 
     In the elastic mesh  9 ′, an inner mesh part  97  located at the innermost side in the radial direction may come in contact with the outer circumferential surface of the bearing  5 . In some implementations, an outer mesh part  99  located at the outermost side in the radial direction may come in contact with the bracket  8 . At least a portion of the outer mesh part  99  may come in contact with the elastic mesh housing part  81  of the bracket  8 . 
     The elastic mesh  9 ′ may further include at least one center mesh part  98  located between the inner mesh part  97  and the outer mesh part  99 . The center mesh part  98  may be curled to surround the inner mesh part  97 , and the outer mesh part  99  may be curled to surround the center mesh part  98 . 
     The elastic mesh  9 ′ may include the inner mesh part  97  and the outer mesh part  99  without the center mesh part  98 . In this case, the outer mesh part  99  may be curled to surround the inner mesh part  97 . 
     In some implementations, the elastic mesh  9 ′ entirely formed in a hollow cylindrical shape can be manufactured through a simple process of curling, plural times, one strip-shaped mesh part in a scroll form. In some implementations, heat can be dissipated through not only the pores formed in the mesh part but also pores between the mesh parts  97 ,  98 , and  99  sequentially arranged in the radial direction. 
       FIG. 8  is a sectional view showing another example motor.  FIG. 9  is an enlarged sectional view of portion B of  FIG. 8 .  FIG. 10  is a cross-sectional view when an example second elastic mesh is elastically deformed by an example second bearing. 
     In some implementations, the motor M may include a second bearing  6 ′ of which external diameter D 5  is smaller than the internal diameter D 4  of a hollow part  12 . The second bearing  6 ′ may be mounted to a rotating shaft  3 . The motor M may further include a second elastic mesh  9 ″ that has a plurality of pores and that is disposed between the inner surface of the hollow part  12  and the outer surface of the second bearing  6 ′. 
     In this implementation, the other components except the second bearing  6 ′ and the second elastic mesh  9 ″ and their operations are identical or similar to those of the aforementioned implementation. Therefore, the components identical or similar to those of the aforementioned implementation are designated by like reference numerals, and their detailed descriptions will be omitted. 
     Only the installation position of the second elastic mesh  9 ″ is different from that of the elastic mesh  9  of the aforementioned implementation, and its detailed structure and function may be identical to those of the elastic mesh  9  of the aforementioned implementation. 
     In some implementations, the motor M may include both of the elastic mesh  9  and the second elastic mesh  9 ″, and the elastic mesh  9  and the second elastic mesh  9 ″ may align the positions of a bearing  5  and the second bearing  6 ′ to positions different from each other. The alignment of the position of the bearing  5  by the elastic mesh  9  is identical to that of the aforementioned implementation, and therefore, its detailed description will be omitted. 
     The second elastic mesh  9 ″ may be press-fitted between an outer rim  62  of the second bearing  6 ′ and the hollow part  12 , and may be fixed to at least one of the outer rim  62  of the second bearing  6 ′ and the hollow part  12  by the thermal conductive adhesive  96  as shown in  FIG. 6 . In some implementations, it will be apparent that the second elastic mesh  9 ″ may have a shape in which a mesh part having a plurality of pores formed therein is curled at least twice as shown in  FIG. 6 . 
     The detailed structure of the second elastic mesh  9 ″ is identical or similar to that of the elastic mesh  9  of the aforementioned implementation, and therefore, its detailed description will be omitted. 
     In some implementations, a second O-ring  64  of this implementation may include an inner ring  65  mounted to the rotating shaft  3  and an outer ring  66  spaced apart from the outer rim  62  of the second bearing  6 ′. In some implementations, the second O-ring  64  may be mounted to the rotating shaft  3  to be located inside the second elastic mesh  9 ″. 
     A gap G 2  may be formed between the outer circumference of the second O-ring  64  and the second elastic mesh  9 ″. 
     In some implementations, the second O-ring  64  may not come in contact with the inner circumferential surface of the second elastic mesh  9 ″, and thus the abrasion of the second elastic mesh  9 ″ and the second O-ring  64  can be minimized. In some implementations, the gap G 2  can assist air flowed by a diffuser  74  to be introduced into the plurality of pores of the second elastic mesh  9 ″. 
     The second bearing  6 ′, as shown in  FIG. 10 , may pressurize a portion of the second elastic mesh  9 ″ in a state in which the center axis B 2  does not correspond to the center axis H 2  of the hollow part  12 . In this case, the second elastic mesh  9 ″ may support the second bearing  6 ′ in the state in which the portion pressurized by the second bearing  6 ′ is compressed. 
     For example, the center axis H 2  of the hollow part  12  shown in  FIG. 10  may not correspond to the center axis H 1  of the elastic mesh housing part  18  shown in  FIG. 4  due to an assembly tolerance of a motor housing  1  and a bracket  8 . In this case, the position of the second bearing  6 ′ may be aligned with the position of the rotating shaft  3  in the state in which the second bearing  6 ′ is supported by the second elastic mesh  9 ″, and the concentricities of the bearing  5  and the second bearing  6 ′ may correspond to each other. 
     In this implementation, at least one of the elastic mesh  9  and the second elastic mesh  9 ″ may be elastically deformed such that the concentricities of the bearing  5  and the second bearing  6 ′ correspond to each other. 
     In some implementations, the concentricities of the bearing  5  and the second bearing  6 ′ may correspond to each other as each of the elastic mesh  9  and the second elastic mesh  9 ″ is elastically deformed according to the assembly tolerance of the motor housing  1  and the bracket  8 . 
     For example, the position of the bearing  5  may be aligned by the elastic mesh  9 , and the position of the second bearing  6 ′ may be aligned by the second elastic mesh  9 ″. In this case, the concentricities of the bearing  5  and the second bearing  6 ′ can smoothly correspond to each other, as compared with the case of the aforementioned implementation. 
     In some implementations, a through-hole  13  facing at least a portion of the second elastic mesh  9 ″ may be formed in the motor housing  1 . A portion of the air flowed by the diffuser  74  may pass through the plurality of pores of the second elastic mesh  9 ″, and the air passing through the plurality of pores of the second elastic mesh  9 ″ may be smoothly discharged to the outside of the motor housing  1  through the through-hole  13 . 
     In some implementations, a flow path through which air passes may be formed between the hollow part  12  and the second bearing  6 ′ by the through-hole  13  formed in the motor housing  1 . The second elastic mesh  9 ″ is disposed in the flow path formed between the hollow part  12  and the second bearing  6 ′, to efficiently dissipate heat transferred from the second bearing  6 ′. 
     Although some implementations of the present disclosure are described for illustrative purposes, it will be apparent to those skilled in the art that various modifications and changes can be made thereto within the scope of the disclosure without departing from the essential features of the disclosure. 
     Accordingly, the aforementioned implementations should be construed not to limit the technical spirit of the present disclosure but to be provided for illustrative purposes so that those skilled in the art can fully understand the spirit of the present disclosure. 
     The scope of the present disclosure should not be limited to the aforementioned implementations but defined by appended claims. The technical spirit within the scope substantially identical with the scope of the present disclosure will be considered to fall in the scope of the present disclosure defined by the appended claims.