Patent Publication Number: US-2020280237-A1

Title: Motor Including Bearing Assembly

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a divisional application of U.S. patent application Ser. No. 16/112,947 filed on Aug. 27, 2018. The application claims the benefit of Taiwan application serial No. 106135117, filed on Oct. 13, 2017, and the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a ball bearing and, more particularly, to a bearing assembly capable of adjusting the gaps between the balls and the inner and outer races thereof. 
     The present invention generally relates to a motor and, more particularly, to a motor including a bearing assembly. 
     2. Description of the Related Art 
     To increase the rotating speed of the rotor, the shaft of the conventional motor is coupled with at least one bearing which may be a self-lubricating bearing or a ball bearing. The at least one bearing is disposed into a bearing seat. As an example of the ball bearing, there are two ball bearings (each including inner and outer races) used. The two ball bearings are spaced from each other in the bearing seat. The inner race is press fit around the shaft, and the outer race is press fit with the bearing seat. Alternatively, an adhesive is applied between the outer race and the bearing seat to fix the outer race to the bearing seat. 
     No matter the outer race is coupled with the bearing seat by press fitting or via the use of the adhesive, the ball bearings can rotate smoothly and do not produce noise in the early time. However, after a certain period of time, the gaps between the balls and the inner and outer races will become larger due to the friction. Thus, noise is generated during the operation of the motor. In a worse case, the ball bearings are even broken and cannot operate anymore. 
     In light of this, it is necessary to improve the bearing structure of the conventional motor. 
     SUMMARY OF THE INVENTION 
     It is therefore the objective of this invention to provide a bearing assembly which has a slit that is adjustable. Specifically, a gap between the outer race of the ball bearing and the bearing seat can be adjusted to permit the outer race of the ball bearing to be securely fixed in the bearing seat. 
     It is another objective of this invention to provide a bearing assembly which has a slit that is adjustable. The balls of the ball bearing can be securely coupled with the inner and outer races of the ball bearing to prevent the noise during the operation of the motor and to prolong the service life of the motor. 
     In an aspect, a bearing assembly including a bearing seat, at least one bearing and a shaft is disclosed. The bearing seat includes a chamber, a shaft-coupling hole and a shaft hole. The shaft-coupling hole and the shaft hole intercommunicate with the chamber. The bearing seat has a slit which is adjustable. The at least one bearing is received in the chamber. The shaft extends through the shaft hole and the at least one bearing and includes at least one abutment portion. The at least one bearing abuts the at least one abutment portion. 
     In another aspect, a motor including a bearing assembly is disclosed. 
     In a further aspect, a motor including a bearing assembly is disclosed. The motor includes a housing, a stator received in the housing, a bearing seat mounted to the housing and having a slit which is adjustable, a bearing received in the bearing seat and including an inner race and an outer race, a shaft extending through the bearing, and a rotor coupled with the shaft and rotating relatively to the stator. 
     Based on the above, via the arrangement of the slit, the bearing assembly according to the invention can misalign the inner race with the outer race by applying pressure to the inner race or the outer race when gaps are formed between the balls and the inner race and the outer race due to the friction therebetween. In this regard, a positioning member can be tightened up to adjust the slit in a size as required, such that the balls can be securely coupled with the inner race and the outer race. Therefore, the motor including the bearing assembly can achieve the advantages of reducing the noise in rotation and increasing the lifespan of the bearings. 
     In an example, the bearing assembly further includes a cover coupled with the bearing seat. Thus, the cover is able to abut the bearing. 
     In the example, the at least one bearing includes an upper bearing relatively distant to the cover and a lower bearing relatively adjacent to the cover. Each of the upper and lower bearings includes an inner race and an outer race. An elastic member is disposed between the cover and the outer race of the lower bearing. 
     In the example, the outer race includes an outer wall fitted with a rubber ring. Thus, a vibration reduction effect can be provided. 
     In the example, the cover includes a central hole, and an annular lip is provided at an edge of the central hole and protrudes from a face of the cover facing the bearing seat. Thus, the elastic member can be positioned. 
     In the example, the inner race has an outer diameter and the outer race has an outer diameter, and the annular lip includes a diameter larger than the outer diameter of the inner race and smaller than the outer diameter of the outer race. Thus, the elastic member can be aligned with the outer race. 
     In the example, the bearing seat includes a plurality of engaging holes on one end face of the bearing seat where the shaft-coupling hole is. The cover has a plurality of through-holes. A plurality of fasteners respectively extends through the plurality of through-holes and is threadedly engaged with the plurality of engaging holes of the bearing seat, respectively. Thus, the assembly is convenient. 
     In the example, the bearing seat has a horizontal through-hole extending through the slit, and a positioning member extends through the horizontal through-hole to adjust the slit. Thus, the adjustment of the slit is convenient. 
     In the example, the slit is formed on an end of the bearing seat where the shaft-coupling hole is, and the slit is radially aligned with one of the at least one bearing. Thus, the fastening effect is improved. 
     In the example, the slit is radially aligned with one of the upper and lower bearings. Thus, the fastening effect is improved. 
     In the example, the slit extends through the bearing seat from an inner periphery to an outer periphery of the bearing seat and intercommunicates with the chamber. Thus, the adjustment of the slit is convenient. 
     In the example, the positioning member includes a screw and a nut. Thus, the assembly is convenient. 
     In the example, the horizontal through-hole is provided with inner threads, and the positioning member is provided with outer threads and is threaded through the inner threads of the horizontal through-hole. Thus, the assembly is convenient. 
     In the example, the elastic member is a rubber ring, a spring or a spring washer. Thus, pressure can be applied to the bearing. 
     In the example, the elastic member surrounds the annular lip and abuts the outer race. Thus, the outer race can be misaligned with the inner race under the arrangement of the slit. 
     In the example, the shaft includes an expansion portion. The expansion portion has an end forming an upper abutment portion and another end forming a lower abutment portion. The inner race of the upper bearing abuts the upper abutment portion, and the outer race of the upper bearing abuts an inner periphery of the bearing seat delimiting the chamber. The inner race of the lower bearing abuts the lower abutment portion, and the outer race of the upper bearing abuts the elastic member. Thus, the upper and lower bearings can be positioned with respect to the shaft. 
     In the example, the bearing seat further includes a protrusion protruding from a top of the bearing seat where the shaft hole is. The protrusion includes a slit extending through the protrusion and intercommunicating with the shaft hole. The protrusion includes a horizontal through-hole extending through the protrusion. A positioning member extends through the horizontal through-hole of the protrusion to adjust the slit. Thus, the adjustment of the slit is convenient. 
     In the example, the positioning member is a screw and a nut. Thus, the assembly is convenient. 
     In the example, the horizontal through-hole of the protrusion is provided with inner threads, and the positioning member is provided with outer threads and is threaded through the inner threads of the horizontal through-hole. Thus, the assembly is convenient. 
     In the example, the slit of the protrusion intercommunicates with the slit of the bearing seat. Thus, the adjustment of the slits is convenient. 
     In the example, the slit is formed on an end of the bearing seat where the shaft hole is and intercommunicates with the shaft hole. Thus, the adjustment of the slits is convenient. 
     In the example, the bearing seat includes a disc at an end of the bearing seat where the shaft-coupling hole is. The slit extends through the disc and towards another end of the bearing seat where the shaft hole is. The disc includes a cutoff portion intercommunicating with the horizontal through-hole. Thus, the adjustment of the slits is convenient. 
     In the example, a bottom plate is coupled with a bottom of the housing and includes a seat coupled with an end of the shaft. Thus, the rotating shaft can be supported. 
     In the example, a support is disposed between the shaft and the seat and is a self-lubricating bearing, an oil bearing or a ball bearing. Thus, the rotating shaft can be positioned more stably. 
     In the example, the inner race has an outer diameter and the outer race has an outer diameter. The bearing seat has a shaft hole. The shaft hole has a diameter larger than the outer diameter of the inner race and smaller than the outer diameter of the outer race. Thus, the top of the bearing seat is able to abut the outer race. 
     In the example, a positioning ring is disposed between the rotor and the shaft and has an end connected to the inner race of the bearing. Thus, the rotor is able to couple with the shaft. 
     In the example, the shaft is coupled with an elastic element. The elastic element has an end connected to an end of the positioning ring, as well as another end connected to an end of the support. Thus, pressure can be applied to the bearing. 
     In the example, the bearing seat includes a horizontal through-hole extending through the slit, and a positioning member extends through the horizontal through-hole to adjust the slit. Thus, the adjustment of the slit is convenient. 
     In the example, the positioning member includes a screw and a nut. Thus, the assembly is convenient. 
     In the example, the horizontal through-hole is provided with inner threads, and the positioning member is provided with outer threads and is threaded through the inner threads of the horizontal through-hole. Thus, the assembly is convenient. 
     In the example, the motor further includes a positioning ring fit around the bearing seat via a hole thereof. The positioning ring includes a slit extending through the positioning ring from an inner periphery delimiting the hole to an outer periphery of the positioning ring. A horizontal through-hole extends through the slit. A positioning member extends through the horizontal through-hole to adjust the slit. Thus, the bearing can be clamped by the bearing seat more securely. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a perspective, exploded view of a bearing assembly for a motor according to a first embodiment of the invention. 
         FIG. 2  is a cross sectional, assembled view of the bearing assembly for the motor according to the first embodiment of the invention. 
         FIG. 3  shows the bearing assembly of  FIG. 2  which further includes a rubber ring coupled with each outer race of a bearing of the bearing assembly. 
         FIG. 4  is a cross sectional view of the bearing assembly for the motor taken along line  4 - 4  in  FIG. 2 . 
         FIG. 5  is a partially enlarged view of  FIG. 2  before a cover is assembled. 
         FIG. 6  is a partially enlarged view of  FIG. 2  after the cover is assembled. 
         FIG. 7  is a cross sectional view of a motor including the bearing assembly of the first embodiment of the invention. 
         FIG. 8  is a perspective view of a bearing assembly for a motor according to a second embodiment of the invention. 
         FIG. 9  is a perspective view of a bearing assembly for a motor according to a third embodiment of the invention. 
         FIG. 10  is a perspective view of a bearing assembly for a motor according to a fourth embodiment of the invention. 
         FIG. 11  is a perspective view of a bearing assembly for a motor according to a fifth embodiment of the invention. 
         FIG. 12  is a perspective view of a bearing assembly for a motor according to a sixth embodiment of the invention. 
         FIG. 13  is a perspective view of a bearing assembly for a motor according to a seventh embodiment of the invention. 
         FIG. 14  is a cross sectional view of an assembled motor including a bearing assembly according to an eighth embodiment of the invention. 
         FIG. 15  is perspective view of a bearing assembly for a motor according to a ninth embodiment of the invention. 
     
    
    
     In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “first”, “second”, “inner”, “outer”, “top”, “bottom”, “axial”, “radial” and similar terms are used hereinafter, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings, and are utilized only to facilitate describing the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a bearing assembly for a motor according to a first embodiment of the invention. The bearing assembly includes a bearing seat  1  and a shaft  2  extending through the bearing seat  1 . 
     Referring to  FIGS. 1 and 2 , the bearing seat  1  includes a chamber S, a shaft-coupling hole  11  and a shaft hole  12  which are intercommunicating with each other. The shaft-coupling hole  11  and the shaft hole  12  are located at two ends of the bearing seat  1 , respectively. Thus, at least one bearing  13  can be disposed into the chamber S via the shaft-coupling hole  11 . In this embodiment, there are two bearings  13  disposed in the chamber S, including an upper bearing  13   a  and a lower bearing  13   b . Each of the upper bearing  13   a  and the lower bearing  13   b  includes an inner race  131 , an outer race  132  and a plurality of balls  133 . The plurality of balls  133  is disposed between the inner race  131  and the outer race  132  to permit the inner race  131  and the outer race  132  to rotate relatively to each other. The inner race  131  has an outer diameter D 1  and the outer race  132  has an outer diameter D 2 . 
     Referring to  FIG. 3 , the outer race  132  further includes an outer wall  132   a  fitted with a rubber ring  134 . When the bearing  13  is disposed in the chamber S, the rubber ring  134  is located between the outer race  132  and an inner wall of the bearing seat  1  to provide a vibration reduction effect. The rubber ring  134  is made of a flexible material such as rubber or silicon. The rubber ring  134  is in an “L” shape and is fit around the outer wall  132   a  of the outer race  132 , as is shown with the upper bearing  13   a  in  FIG. 3 . Alternatively, the rubber ring  134  is in the form of a sleeve fit around the outer wall  132   a  of the outer race  132 , as is shown with the lower bearing  13   b  in  FIG. 3 . 
     Referring to  FIGS. 1 and 2 , the bearing seat  1  further includes a plurality of engaging holes  14  on one end face of the bearing seat  1  where the shaft-coupling hole  11  is. Each of the plurality of engaging holes  14  can be engaged with a fastener  32 . The bearing seat  1  further includes a slit  15  which is adjustable and preferably radially aligned with the bearing  13 . The slit  15  extends through the bearing seat  1  and intercommunicates with the chamber S and the shaft-coupling hole  11 . The bearing seat  1  has a horizontal through-hole  16  extending through the slit  15  and radially aligned with the bearing  13 . A positioning member  17  can extend through the horizontal through-hole  16  to adjust the slit  15  in a size as required. The positioning member  17  includes a screw and a nut. Alternatively, the horizontal through-hole  16  is provided with inner threads. In this regard, the positioning member  17  is provided with outer threads and threaded through the inner threads of the horizontal through-hole  16 , thereby adjusting the size of the slit  15 . Accordingly, the bearing seat  1  can firmly clamp the bearing  13 . 
     Referring to  FIGS. 1 and 2 , the shaft  2  extends through the chamber S of the bearing seat  1 . Two ends of the shaft  2  extend out of the shaft-coupling hole  11  and the shaft hole  12  of the bearing seat  1 , respectively. To couple the shaft  2  with the bearing seat  1  without relative rotation, the shaft  2  includes at least one abutment portion  21 . The inner race  131  of the bearing  13  abuts the abutment portion  21 . In this embodiment, the shaft  2  includes an expansion portion  20 . The expansion portion  20  has an end forming an upper abutment portion  21   a  and another end forming a lower abutment portion  21   b . Furthermore, the abutment portion  21  can be formed in an integral or mold-injecting manner or is press fit with a sleeve to form a diameter difference between the sleeve and the shaft  2 . 
     Referring to  FIGS. 1 and 2 , the bearing assembly for the motor according to the first embodiment of the invention further may include a cover  3  having a plurality of through-holes  31  and a plurality of fasteners  32 . Each of the plurality of through-holes  31  is aligned with a respective engaging hole  14 . Each of the plurality of fasteners  32  can extend through a respective through-hole  31  and a respective engaging hole  14 . The fastener  32  preferably couples with the engaging hole  14  by threaded engagement to fix the cover  3  to the end of the bearing seat  1  where the shaft-coupling hole  11  is. The cover  3  further includes a central hole  33 . An annular lip  34  is provided at an edge of the central hole  33  and protrudes from the face of the cover  3  facing the bearing seat  1 . The annular lip  34  includes a diameter D 3  larger than the outer diameter D 1  of the inner race  131  and smaller than the outer diameter D 2  of the outer race  132 . 
     Referring to  FIGS. 1 and 2 , an elastic member  35  may be disposed between the annular lip  34  and the outer race  132 . The elastic member  35  is preferably disposed on the outer periphery of the annular lip  34  and abuts the outer race  132 . Therefore, the elastic member  35  can apply pressure to the outer race  132 . The elastic member  35  can be a conventional rubber ring, a spring or a spring washer. 
     Referring to  FIGS. 2, 4 and 5 , the shaft  2  extends through the bearing seat  1  in a manner that the two ends of the shaft  2  extend out of the shaft-coupling hole  11  and the shaft hole  12  of the bearing seat  1 , respectively. The inner races  131  of the bearings  13  are securely coupled with the shaft  2 , and the outer races  132  of the bearings  13  are securely coupled with an inner periphery of the bearing seat  1  delimiting the chamber S. The cover  3  is fixed to the end of the bearing seat  1  where the shaft-coupling hole  11  is. The inner race  131  of the upper bearing  13   a  abuts the upper abutment portion  21   a  of the shaft  2 , and the outer race  132  of the upper bearing  13   a  abuts the bearing seat  1 . The inner race  131  of the lower bearing  13   b  abuts the lower abutment portion  21   b  of the shaft  2 , and the elastic member  35  abuts the outer race  132  of the lower bearing  13   b . Therefore, the bearings  13  are coupled with the shaft  2 . In addition, by extending the positioning member  17  through the horizontal through-hole  16 , the tops of the inner race  131  and the outer race  132  are aligned with each other and the bottoms of the inner race  131  and the outer race  132  are aligned with each other. Thus, the plurality of balls  133  can be firmly coupled with the inner race  131  and the outer race  132 . 
     Referring to  FIG. 6 , after the motor is used for a long time, gaps are formed between the balls  133  and the inner race  131  and the outer race  132  due to the friction therebetween. In this situation, the positioning member  17  can be loosened. Since the elastic member  35  surrounds the annular lip  34  and abuts the outer race  132 , the pressure that the outer race  132  exerts on the inner race  131  can be adjusted to reduce the distance between the cover  3  and the top of the bearing seat  1 . As a result, the outer race  132  is misaligned with the inner race  131 , causing misalignment between the tops of the inner race  131  and the outer race  132  and between the bottoms of the inner race  131  and the outer race  132 . This enables the plurality of balls  133  to be firmly coupled with the inner race  131  and the outer race  132  again. At this time, the positioning member  17  can be tightened to reduce the slit  15  of the bearing seat  1 , such that the bearing seat  1  can properly clamp the bearing  13 . 
     Referring to  FIG. 7 , the bearing seat  1  further includes an engagement face  10  having a plurality of positioning holes  101 . A fastener  8  extends into a respective positioning hole  101  to couple a housing  4  of a motor with the bearing seat  1 . The housing  4  accommodates a stator  42 , a circuit board  43 , and a permanent magnet  7  mounted to an inner periphery of the housing  4 . The housing  4  and the bearing seat  1  can rotate relatively to the stator  42 . As the motor is used for a long time where gaps are formed between the balls  133  and the inner race  131  and the outer race  132  due to the friction therebetween, the positioning member  17  can be loosened for the elastic member  35  to adjust the pressure the outer race  132  exerts on the inner race  131 . In this regard, the outer race  132  is misaligned with the inner race  131  to permit the balls  133  to firmly connect to the inner race  131  and the outer race  132  again. Then, the positioning member  17  is tightened up to permit the bearing seat  1  to properly clamp the bearing  13 . Thus, the housing  4  and the bearing seat  1  can smoothly rotate relatively to the stator  42  to reduce the noise in rotation and to increase the lifespan of the bearings  13 . 
       FIG. 8  shows a bearing assembly for a motor according to a second embodiment of the invention. As compared with the first embodiment, the bearing seat  1  in the second embodiment further includes a protrusion  18  protruding from a top of the bearing seat  1  where the shaft hole  12  is. The protrusion  18  also includes a slit  15 ′ which is adjustable. The slit  15 ′ extends through the protrusion  18  and intercommunicates with the shaft hole  12 . The protrusion  18  also includes a horizontal through-hole  16 ′ extending through the protrusion  18 . A positioning member  17  can extend through the horizontal through-hole  16 ′. The positioning member  17  may be a screw and a nut. Alternatively, the horizontal through-hole  16 ′ includes inner threads such that the threaded positioning member  17  can be directly screwed through the horizontal through-hole  16 ′ to adjust the slit  15 ′. In this regard, since the bearing seat  1  includes two slits  15  and  15 ′ and two horizontal through-holes  16  and  16 ′, each positioning member  17  can be operated to adjust a corresponding slit  15  or  15 ′ in a size as required when the motor is used for a long time where gaps are formed between the balls  133  and the inner race  131  and the outer race  132  due to the friction therebetween. This permits the bearing seat  1  to firmly clamp the bearing  13  as shown in  FIG. 2 . 
       FIG. 9  shows a bearing assembly for a motor according to a third embodiment of the invention. As compared with the second embodiment, the slit  15  in this embodiment intercommunicates with the slit  15 ′ of the protrusion  18 . A positioning member  17  can extend through the horizontal through-hole  16 , and another positioning member  17  can also extend through the horizontal through-hole  16 ′ of the protrusion  18 . In this arrangement, as the motor is used for a long time where gaps are formed between the balls  133  and the inner race  131  and the outer race  132  due to the friction therebetween, each positioning member  17  can be operated to adjust a corresponding slit  15  or  15 ′ in a size as required. Advantageously, the bearing seat  1  is able to clamp the bearing  13  more securely as is shown in  FIG. 2 . 
       FIG. 10  shows a bearing assembly for a motor according to a fourth embodiment of the invention. As compared with the second embodiment, the bearing seat  1  in the fourth embodiment further includes a protrusion  18  protruding from an outer periphery of the bearing seat  1  at an end of the shaft hole  12 . The protrusion  18  also includes a slit  15 ′ which is adjustable. The slit  15 ′ extends through the protrusion  18  and intercommunicates with the shaft hole  12 . The protrusion  18  includes a horizontal through-hole  16 ′ extending through the protrusion  18 . A positioning member  17  can extend through the horizontal through-hole  16 ′. The positioning member  17  may be a screw and a nut. Alternatively, the horizontal through-hole  16 ′ includes inner threads such that the threaded positioning member  17  can be directly screwed through the horizontal through-hole  16 ′ to adjust the slit  15 ′ in a size as required. In this regard, since the bearing seat  1  includes two slits  15  and  15 ′ and two horizontal through-holes  16  and  16 ′, each positioning member  17  can be operated to adjust a corresponding slit  15  or  15 ′ in a size as required when the motor is used for a long time where gaps are formed between the balls  133  and the inner race  131  and the outer race  132  due to the friction therebetween. This permits the bearing seat  1  to firmly clamp the bearing  13  as shown in FIG.  2 . 
       FIG. 11  shows a bearing assembly for a motor according to a fifth embodiment of the invention. As compared with the fourth embodiment, the slit  15 ′ is formed on an end of the bearing seat  1  where the shaft hole  12  is. The slit  15 ′ extends through the bearing seat  1  from the inner periphery to the outer periphery thereof and intercommunicates with the shaft hole  12 . The horizontal through-hole  16 ′ extends through the slit  15 ′. A positioning member  17  can extend through the horizontal through-hole  16 ′. The positioning member  17  may be a screw and a nut. Alternatively, the horizontal through-hole  16 ′ includes inner threads such that the threaded positioning member  17  can be directly screwed through the horizontal through-hole  16 ′ to adjust the slit  15 ′ in a size as required. In this regard, each positioning member  17  can be operated to adjust the slit  15  in a size as required when the motor is used for a long time where gaps are formed between the balls  133  and the inner race  131  and the outer race  132  due to the friction therebetween. This permits the bearing seat  1  to firmly clamp the bearing  13  as shown in  FIG. 2 . 
       FIG. 12  shows a bearing assembly for a motor according to a sixth embodiment of the invention. As compared with the fifth embodiment, the bearing seat  1  includes a disc  19  at an end of the bearing seat  1  where the shaft-coupling hole  11  is. The slit  15  extends through the disc  19  and towards another end of the bearing seat  1  where the shaft hole  12  is. The horizontal through-hole  16  extends through the slit  15 . The disc  19  includes a cutoff portion  191  intercommunicating with the horizontal through-hole  16  to permit the positioning member  17  to extend into the horizontal through-hole  16 . In this arrangement, the slit  15  can be adjusted in a size as required for the bearing seat  1  to firmly clamp the bearing  13  as is shown in  FIG. 2 . 
       FIGS. 13 and 14  show a motor including the bearing assembly according to an embodiment of the invention. The motor includes a housing  4  having a compartment R. The compartment R has an opening coupled with a bottom plate  41 . The bottom plate  41  is located at an end of the housing  4 . The housing  4  includes a stator  42  and a circuit board  43 . The bottom plate  41  includes a seat  44  that can support a shaft  5  that rotates. A support  45  is preferably disposed between the shaft  5  and the seat  44 . The support  45  may be a conventional self-lubricating bearing, an oil bearing, a ball bearing or the like that provides the shaft  5  with stable rotation. The support  45  is a ball bearing in this embodiment. The housing  4  further includes a bearing seat  46  having a shaft hole  461 . The shaft hole  461  has a diameter D 4 . An end of the shaft  5  extends through the shaft hole  461 . A bearing  13  is received in the bearing seat  46  and includes an inner race  131 , an outer race  132  and a plurality of balls  133 . The inner race  131  has an outer diameter D 1  and the outer race  132  has an outer diameter D 2 . The diameter D 4  of the shaft hole  461  is larger than the outer diameter D 1  of the inner race  131  but is smaller than the outer diameter D 2  of the outer race  132 , permitting the top of the bearing seat  46  to abut the outer race  132 . The bearing seat  46  includes a slit  462  and a horizontal through-hole  463 . The slit  462  is adjustable. A positioning member  17  can extend through the horizontal through-hole  463  to adjust the slit  462  in a size as required. 
     Referring to  FIGS. 13 and 14 , the shaft  5  has an end that abuts the support  45  and rotates thereupon. The shaft  5  is coupled with a rotor  51  and an elastic element  52 . The rotor  51  rotates relatively to the stator  42 . A positioning ring  53  is preferably disposed between the rotor  51  and the shaft  5 , such that the rotor  51  can be coupled with the shaft  5 . The elastic element  52  has an end connected to the support  45 , as well as another end connected to an end of the positioning ring  53 . Another end of the positioning ring  53  is connected to the other inner race  131  of the other bearing  13 . The elastic element  52  can apply pressure to the inner race  131 , thereby securely coupling the plurality of balls  133  with the inner race  131  and the outer race  132 . 
     Referring to  FIGS. 13 and 14  again, as the motor is used for a long time where gaps are formed between the balls  133  and the inner race  131  and the outer race  132  due to the friction therebetween, the positioning member  17  can be loosened. Due to the arrangement of the elastic element  52 , the elastic element  52  pushes the positioning ring  53  and the shaft  5  upwards in an axial direction by applying pressure thereto. Accordingly, the inner race  131  moves relatively to the outer race  132 . This permits the plurality of balls  133  to securely couple with the inner race  131  and the outer race  132  again. In this regard, the positioning member  17  can be tightened up to reduce the slit  15  of the bearing seat  46 , permitting the bearing seat  46  to firmly clamp the bearing  13 . In this arrangement, the shaft  5  can smoothly rotate relatively to the bearing seat  46  again, thus reducing the noise during the operation and increasing the lifespan of the bearing  13 . 
       FIGS. 14 and 15  show a motor including the bearing assembly according to another embodiment of the invention. In this embodiment, the slit  462  can be adjusted by a positioning ring  6 . The positioning ring  6  includes a hole  61 , a slit  62  and a horizontal through-hole  63 . The positioning ring  6  is fit around the bearing seat  46 . The slit  62  extends through the positioning ring  6  from an inner periphery delimiting the hole  61  to an outer periphery thereof. The horizontal through-hole  63  extends through the slit  62 . A positioning member  17  can extend through the horizontal through-hole  63  to adjust the slit  62  in a size as required. Therefore, via the use of the positioning ring  6 , the bearing  13  can be firmly clamped by the bearing seat  46 . This makes the shaft  5  rotate relatively to the bearing seat  46  more smoothly, reducing the noise in rotation and increasing the lifespan of the bearing  13 . 
     In summary, via the arrangement of the slit, the bearing assembly according to the invention can misalign the inner race with the outer race by applying pressure to the inner race or the outer race when gaps are formed between the balls and the inner race and the outer race due to the friction therebetween. In this regard, a positioning member can be tightened up to adjust the slit in a size as required, such that the balls can be securely coupled with the inner race and the outer race. Therefore, the motor including the bearing assembly can achieve the advantages of reducing the noise in rotation and increasing the lifespan of the bearings. 
     Although the invention has been described in detail with reference to its presently preferable embodiments, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims