Patent Publication Number: US-2023163653-A1

Title: Motor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/794,794, filed on Feb. 19, 2020, which claims the benefit of Korean Patent Application No. 10-2019-0084976, filed on Jul. 15, 2019. The disclosures of the prior applications are incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     Various embodiments of the present disclosure relate to a motor in which a structure of an insulator is improved. 
     BACKGROUND 
     A general motor realizes a driving force via interaction between a stator and a rotor. Basically, structures of the stator and the rotor are the same. 
     However, types of the motors are divided based on a principle of rotation of the rotor due to the interaction between the stator and the rotor. In addition, the types of the motors may be divided based on a type or a phase of power applied to a stator coil. In addition, the types of the motors may be divided depending on a scheme for winding the stator coil. In an example, a variable voltage motor is of a direct current type, while a 3-phase induction motor is of an alternating current type. 
     A general structure of the motor includes a rotation shaft, a rotor coupled to the shaft, and a stator fixedly disposed inside a housing. Further, the stator surrounds the rotor and is spaced from the rotor by a predetermined spacing. 
     In addition, the stator has teeth to wind a coil therearound to generate a rotating magnetic field, thereby inducing electrical interaction between the rotor and the stator to induce rotation of the rotor. 
     A scheme for winding the coil may include a concentrated winding scheme and a distributed winding scheme. In the concentrated winding scheme, the coil is wound in one slot in a concentrated manner. Further, the distributed winding scheme, the coil is wound in at least two slots in a divided manner. 
     In the concentrated winding scheme, copper loss may be reduced via reducing a winding amount, compared to the distributed winding scheme. However, the coil is excessively concentrated in the slot, causing a large change in a magnetic flux density and increasing core loss (or iron loss), that is, power loss of the iron core. Thus, the concentrated winding scheme is generally used in a small motor. 
     Recently, motors used in various home appliances (such as hair dryers, cleaners, and the like) have been developed to overcome spatial restriction and improve an insulation performance due to demands of miniaturization and performance improvement. 
     In order to improve the performance of the motor, it is necessary to increase the number of windings of the coil in a winding space or increase a diameter of the coil. However, the winding space defined between the teeth of the stator is limited in size. Insulation of the coil is not secured when a size of the stator is reduced to follow a trend of lightening the motor. This may adversely affect the performance of the motor. 
     In Patent Document 1 (KR 10-2015-0031634, published on Mar. 25, 2015), a structure of an insulator is simplified by arranging terminals with the same shape such that center axes of virtual circles formed by extending an inner circumferential faces thereof are different from each other. Further, Patent Document 2 (KR 10-2017-0052986, published on May 15, 2017) discloses a structure in which a fixing portion protruding from a bus-bar is inserted into a slot portion defined in an insulator to couple the bus-bar and a stator with each other. Further, Patent Document 3 (KR 10-2016-0139824, published on Dec. 7, 2016) discloses a structure in which a structure of a terminal of a bus-bar is improved, so that the terminal is fitted to a top face of a stator in an annular structure. Further, Patent document 4 (KR 10-2016-0030924, published on Mar. 21, 2016) discloses a structure in which input/output terminals of a bus-bar are alternately arranged in a vertical direction on an outer circumference. 
     However, in the structures of the bus-bar and the insulator applied to the above-mentioned patent documents, a plurality of bus-bars are arranged inwardly of an outer diameter of the motor, and connection of lead wires is achieved while winding the lead wires around the insulator. This requires a lot of space in a radial direction. 
     In particular, when the terminals are located on the same plane as in the structure of Patent Document 1, utilization of the space is increased, but a lot of space is required in the radial direction as described for securing insulation between the terminals. Further, when the space in the radial direction is reduced, it is difficult to secure the insulation. 
     Therefore, there is a need for structural improvement allowing achieving miniaturization of the motor and at the same time ensuring the insulation performance. 
     PRIOR ART DOCUMENT 
     Patent Document 
     
         
         Patent Document 1: KR 10-2015-0031634 (published on Mar. 25, 2015) 
         Patent Document 2: KR 10-2017-0052986 (published on May 15, 2017) 
         Patent Document 3: KR 10-2016-0139824 (published on Dec. 7, 2016) 
         Patent document 4: KR 10-2016-0030924 (published on Mar. 21, 2016) 
       
    
     SUMMARY 
     One purpose of the present disclosure is to provide a motor with improved bus-bar and insulator structures by which spatial restrictions caused by miniaturization of the motor may be overcome. 
     Further, another purpose of the present disclosure is to provide a motor with improved bus-bar and insulator structures by which the motor is minimized while insulation performance is secured. 
     Further, another purpose of the present disclosure is to provide a high-speed 3-phase motor having a teeth-divided core and a concentrated winding to ensure performance improvement and miniaturization. 
     Further, another purpose of the present disclosure is to provide a motor in which connections of U, V, and W phases lead wires and neutral-point lead wires to terminals may be achieved while overcoming spatial restriction in a stator&#39;s outer diameter and a radial direction of a back yoke. 
     Further, another purpose of the present disclosure is to provide a motor with an improved insulator structure such that an insulation distance for each of U, V, W, and neutral-point lead wires may be secured while overcoming spatial restriction in a radial direction of a back yoke. 
     Further, another purpose of the present disclosure is to provide a motor in which connection of a bus-bar and an insulator is realized within a radial region of a stator core for miniaturization of the motor. 
     Further, another purpose of the present disclosure is to provide a motor in which a teeth-divided core is coupled to a stator core in an axial direction for connection of the lead wires to terminals. 
     Purposes of the present disclosure are not limited to the above-mentioned purpose. Other purposes and advantages of the present disclosure as not mentioned above may be understood from following descriptions and more clearly understood from embodiments of the present disclosure. Further, it will be readily appreciated that the purposes and advantages of the present disclosure may be realized by features and combinations thereof as disclosed in the claims. 
     To achieve the various purpose of the present disclosure, an exemplary embodiment of the present disclosure provides a motor in which a bus-bar, a neutral-point lead wire, and an insulator are vertically stacked. 
     An exemplary embodiment of the present disclosure provides a motor in which connection of the U, V, and W phases lead wires to terminals and connection of the neutral-point lead wires to terminals may be realized in opposite faces of the stator core. 
     An exemplary embodiment of the present disclosure provides a motor in which insulation performance may be improved by ensuring an insulation distance between a stator core, a bus-bar (U, V, and W phases lead wires), and a neutral-point lead wire connection ring. 
     In a first aspect, the present disclosure proposes a motor comprising: a stator; and a rotor rotatable with respect to the stator, wherein the stator includes: a stator core defining a back yoke; teeth extending radially from the back yoke; each coil wound around each tooth, wherein ends of the coils are respectively drawn out of the teeth to define 3-phases power lead wires of the coils; and an insulator module coupled to a top face of the stator core, wherein the insulator module includes: each power terminal unit connected to each of the 3-phases power lead wires; a neutral terminal unit connected to a neutral point of the coil; and an insulator body for achieving insulations between the power and neutral terminal units and the stator core, and between the power and neutral terminal units, wherein the power terminal unit and the neutral terminal unit are positioned at different vertical levels. 
     In one implementation, each power terminal unit includes: a power terminal disposed on a top face of the insulator body and connected to each of the 3-phases power lead wires; and a connection terminal connected to the power terminal and thus connected to each of the 3-phases power lead wires. 
     In one implementation, the power terminal includes: a power terminal body protruding from the top face of the insulator body; and a guide groove defined in the power terminal body to receive and guide each of the 3-phase power lead wires. 
     In one implementation, each power terminal unit includes a power connecting member having one end connected to the power terminal and the other end connected to the connection terminal. 
     The motor of claim  4 , wherein the power connecting member is disposed on a portion of a top face of the insulator body. 
     In one implementation, each of the 3-phases lead wires is drawn radially and outwardly of the back yoke and is connected to each power terminal. 
     In one implementation, the other ends of the coils are respectively drawn out of the teeth to define neutral-point lead wires of the coils, wherein the neutral terminal unit includes: each neutral terminal protruding in a radial direction of the back yoke and connected to each neutral-point lead wire; and a neutral connecting member for connecting the neutral terminals with each other. 
     In one implementation, the neutral connecting member defines a portion of an inner face of the insulator module. 
     In one implementation, the neutral terminals have the same vertical level. 
     In one implementation, the insulator body includes: a lower insulator body positioned on a top face of the stator core to insulate the stator core from the neutral terminal unit; and an upper insulator body positioned on a top face of the lower insulator body to insulate the neutral terminal unit from the power terminal unit. 
     In one implementation, the lower insulator body includes a first face in contact with a top face of the stator core, and a second face having a receiving groove defined therein for receiving the neutral terminal unit therein, wherein the upper insulator body includes a third face being in contact with the second face and having a receiving groove defined therein for receiving the neutral terminal unit therein, and a fourth face having a receiving groove defined therein for receiving the power terminal unit therein. 
     In one implementation, the third face and the fourth face are spaced apart by a predetermined vertical dimension from each other so that a height of the upper insulator body has the predetermined dimension, wherein a sum of vertical dimensions of the receiving grooves formed in the third and fourth faces respectively is smaller than the predetermined dimension. 
     In a second aspect, the present disclosure proposes a motor comprising: a stator; and a rotor rotatable with respect to the stator, wherein the stator includes: a stator core having an inner circumferential face defining a back yoke, and a groove defined along the inner circumferential face; teeth, each tooth including a coupling portion received in the groove and a wound portion extending from the coupling portion radially and inwardly of the back yoke; each coil wound around each tooth; and an insulator module coupled to a top face of the stator core, wherein the insulator module includes: a plurality of terminal units connected to the coils; and an insulator body for insulating the terminal units from the stator core and for insulating between the plurality of terminal units, wherein the plurality of terminal units and the insulator body are stacked vertically to form the insulator module. 
     In one implementation, ends of the coils are respectively drawn out of the teeth to define 3-phases power lead wires of the coils, while the other ends of the coils are respectively drawn out of the teeth to define neutral-point lead wires of the coils, wherein the plurality of terminals includes: each power terminal unit connected to each of the 3-phases power lead wires; and a neutral terminal unit connected to the neutral-point lead wires. 
     In one implementation, each power terminal unit includes each power terminal connected to each of the 3-phases power lead wires and disposed on a top face of the insulator body and in a radial region of the back yoke, wherein the neutral terminal unit includes each neutral terminal connected to each neutral-point lead wire and disposed radially and inwardly of the back yoke. 
     In one implementation, each of the 3-phases lead wires is drawn radially and outwardly of the back yoke and is connected to each power terminal. 
     In one implementation, each power terminal unit further includes: a connection terminal connected to the power terminal and thus connected to each of the 3-phases power lead wires; and a power connecting member having one end connected to the power terminal and the other end connected to the connection terminal. 
     In one implementation, the connection terminal and the power connecting member are located in a radial region of the insulator body. 
     In one implementation, each of the neutral-point lead wires is connected to each neutral terminal disposed inwardly of the insulator body. 
     In one implementation, the neutral terminal unit further includes a neutral connecting member for connecting the neutral terminals with each other, wherein the neutral connecting member is disposed in a groove defined in an inner face of the insulator body. 
     The features of the above-described embodiments may be implemented in a combined manner in other embodiments as long as they are not inconsistent with other embodiments. 
     Effects of the present disclosure are as follows but are not limited thereto. 
     According to the present disclosure, an outer diameter of the stator may be reduced and a radial thickness of the back yoke may be reduced, thereby realizing miniaturization and weight lightening of the motor. 
     In addition, connection of the 3-phases (U, V, W) and neutral-point lead wires to the terminals may be achieved while not being limited based on the radial thickness of the back yoke. 
     In addition, the insulator module is coupled to the stator core in the axial direction. This may minimize the radial thickness of the stator core such that the motor may be miniaturized. 
     In addition, the insulation distances between the stator core and the bus-bar (U, V, and W phases lead wires) and the neutral-point lead wire connection ring are secured to ensure insulation improvement. 
     In addition, in order to speed up and miniaturize the motor, the concentrated winding scheme around the teeth-divided core may be applied. The teeth-divided core may be axially coupled to the stator core to facilitate the lead wire connection to the terminals. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings: 
         FIG.  1    is a perspective view of a conventional cleaner. 
         FIG.  2    is a plan view illustrating winding of a conventional coil. 
         FIG.  3    shows an overall configuration of a motor according to an embodiment of the present disclosure. 
         FIG.  4    is an exploded perspective view of a motor according to one embodiment of the present disclosure. 
         FIG.  5 A  is a perspective view of a divided-core of  FIG.  4   . 
         FIG.  5 B  is a cross-sectional view taken along a line of a-a′ of  FIG.  5 A . 
         FIG.  6 A  is a perspective view of an insulator module of  FIG.  4   . 
         FIG.  6 B  shows a cross section view taken along a line of a-a′ of  FIG.  6 A . 
         FIG.  7    is a perspective view of a state in which a power terminal unit is separated from an insulator module. 
         FIG.  8    is a perspective view of a state in which a neutral terminal unit is separated from an insulator module. 
         FIG.  9    is an exploded perspective view of an insulator module. 
         FIG.  10    is a perspective view of a motor according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     For simplicity and clarity of illustration, elements in the figures are not necessarily drawn to scale. The same reference numbers in different figures denote the same or similar elements, and as such perform similar functionality. Further, descriptions and details of well-known steps and elements are omitted for simplicity of the description. Furthermore, in the following detailed description of the present disclosure, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be understood that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the present disclosure. 
     Examples of various embodiments are illustrated and described further below. It will be understood that the description herein is not intended to limit the claims to the specific embodiments described. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the present disclosure as defined by the appended claims. 
     It will be understood that, although the terms “first”, “second”, “third”, and so on may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section described below could be termed a second element, component, region, layer or section, without departing from the spirit and scope of the present disclosure. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes”, and “including” when used in this specification, specify the presence of the stated features, integers, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, operations, elements, components, and/or portions thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expression such as “at least one of” when preceding a list of elements may modify the entire list of elements and may not modify the individual elements of the list. 
     Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this inventive concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
       FIG.  1    is a perspective view of a conventional cleaner. 
     Referring to  FIG.  1   , a vacuum cleaner may include a cleaner main body  1  with a motor for generating a suction force, a suction nozzle  6  for sucking air containing dust, and an extension tube  5  for connecting the cleaner main body  1  and the suction nozzle  6  with each other. 
     Although not shown, the suction nozzle  6  may be directly connected to the cleaner main body  1  without the extension tube  5 . 
     The cleaner main body  1  may include a dust container  2  in which dust separated from air is stored. Accordingly, dust introduced through the suction nozzle  6  may be stored in the dust container  2  through the extension tube  5 . 
     The cleaner main body  1  may be provided with a handle  3  for a user to grip. The user may perform cleaning while gripping the handle  3 . The cleaner main body  1  may include a battery (not shown), and the cleaner main body  1  may include a battery accommodating portion  4  in which the battery (not shown) is accommodated. The battery accommodating portion  4  may be provided below the handle  3 . The battery (not shown) may be connected to the suction nozzle  6  to supply power to the suction nozzle  6 . 
       FIG.  2    is a plan view illustrating winding of a conventional coil. 
     Referring to  FIG.  2   , a structure of a conventional inner rotor type motor and coil winding thereof will be described. In the conventional inner rotor type motor, teeth  83  extend from a stator core  82  radially inwardly of the stator core  82 . The conventional inner rotor type motor may include an insulator  84  for insulating the stator core  82  from the coil. 
     In the conventional coil winding, a u-phase coil  85   u  is wound around a 1st tooth  83  clockwise (in a direction of an arrow). The coil does not necessarily have to be wound clockwise. In either case, coils of respective phases have to be wound in the same direction. 
     When the coil winding around the tooth  83  is finished, the u-phase coil  85   u  is drawn out of the insulator  84  and then is wound around 4th and 7th teeth sequentially in the same direction as the direction in which the coil is wound around the 1st tooth. Thus, two coil connection wires  86   u  may be formed outwardly of the insulator  84 . Similarly, a v-phase coil  85   v  is wound around 2nd, 5th, and 8th teeth sequentially in the same manner as the winding manner of the u-phase coil. Thus, two connection wires  86   v  may be formed. Further, a w-phase coil  85   w  is wounded around 3rd, 6th, and 9th teeth sequentially. Thus, two connection wires  86   w  may be formed. The 3-phases power coils are wound around the 9th, 8th, and 7th teeth, respectively, and then are drawn out of the insulator  84  and are joined with each other to form a neutral-point lead wire  87  outwardly of the insulator  84 . 
     The connection wires  86  extend along an outer circumferential face of the insulator. Further, arrangement and insulation of the connection wires  86  are performed by utilizing a radial thickness of a back yoke defining the stator core  82 . 
     That is, in the conventional motor, the arrangement and insulation of the lead wires of the coils are performed using the radial thickness of the back yoke. This causes difficulty in miniaturizing and reducing an overall size of the motor. In addition, although not shown in the drawing, a terminal to connect to each of the 3-phases power lead wires and the neutral-point lead wire should be disposed within the radial thickness of the back yoke to secure an insulation distance. 
       FIG.  1    and  FIG.  2    as described above have described the schematic configurations of the small motor and the inner rotor type motor used in the cleaners. A motor to be described in following embodiments of the present disclosure is also a small motor used in the cleaner or the like. The motor includes an insulator structure allowing securing an insulation performance of the motor while reducing a size and a weight of the motor. 
     Hereinafter, a motor according to an embodiment of the present disclosure will be described with reference to  FIGS.  3  to  10   . 
       FIG.  3    shows an overall configuration of a motor according to an embodiment of the present disclosure. 
       FIG.  3    shows an overall motor structure of the present embodiment. Connection and insulation structures of the coils and a structure of the insulator will be omitted in  FIG.  3   . Those omitted in the present drawing will be described in  FIGS.  4  to  10    below. It will be understood that the features of  FIGS.  4  to  10    are applied to the overall configuration of  FIG.  3   . 
     A motor assembly in accordance with the present embodiment includes a motor  20 , a housing for receiving the motor  20  therein and defining an overall frame of the motor, a flow generator  30  installed on a top of the housing to generate air flow, and a diffuser  40  for dispersing the air flow generated by the flow generator  30 . 
     The motor  20  includes an annular stator  21 , a shaft  23  penetrating a center of the stator  21 , and a rotor  22  into which the shaft  23  is mounted. The rotor  22  generates a rotational force via interaction with the stator  21 . Further, the shaft  23  is rotatably supported by a bearing  24 . 
     The motor  20  of the present embodiment is illustrated as a brushless direct current motor (BLDC motor). In the present drawing about the BLDC motor, a structure in which the stator  21  is disposed outwardly of the rotor  22  is illustrated. However, the present disclosure is not limited thereto. A motor having a structure in which the stator  21  is disposed inwardly of the rotor  22  is not excluded. 
     In the drawing, the motor housing  10  is shown below the motor  20  and has a space defined therein for accommodating the motor  20  therein. The motor housing  10  includes a cylindrical motor mounting portion  11  with an open top, a connection arm  14  radially outwardly extending from an upper end of the motor mounting portion  11 , and an annular body coupling portion  15  provided at an end of the connection arm  14  and having a diameter larger than that of the motor mounting portion  11 . A bottom center portion of the motor mounting portion  11  may include a bearing support  12  for fixing and supporting a bearing  24  at a lower portion of the motor  20 . 
     The bearing  24  may be installed in a form of a bearing assembly in which a bearing holder  70  and an elastic mesh  60  are sequentially wound on an outer circumferential face of the bearing  24 . 
     A bracket  50 , the diffuser  40 , and the flow generator  30  may be provided above the motor  20 , and the flow generator  30  may include an impeller  31  and an impeller cover  33 . 
     The bracket  50  may include a center portion  54  aligned with a hole  45  defined in a central portion of the diffuser and a support  51  formed in an annular shape and having a radius larger than that of the center portion  54 . Further, a connecting portion  53  for connecting the center portion  54  and the support  51  with each other may be formed. 
     In addition, the support  51  may include a fastening portion  52  protruding in a radial direction to be fastened to the motor housing  10 , thereby supporting an upper portion of the motor  20 . 
     The diffuser  40  has the hole  45  defined in the center portion thereof. 
     Further, a plurality of cooling flow path outlets  43  are provided along an outer circumferential face of the hole  45  to define flow paths through which heat generated by the motor  20  discharges. 
     In one example, a cylindrical portion  412  for forming an outer diameter corresponding to an outer diameter of a side wall of the motor mounting portion  11  along a radial direction of the diffuser  40  is formed and a plurality of vanes  42  are formed along an outer circumferential face of the cylindrical portion  412 , thereby guiding flow of air pressurized by the impeller  31 . 
     The impeller  31  is installed above the diffuser  40 , and a shaft hole  312  into which the shaft  23  is inserted is provided at a center of the impeller  31 . The impeller  31  may be a diagonal flow type impeller in which the shaft hole  312  is defined in a hub  311  that supports the impeller  31  for securing an overall rigidity thereof, the hub  311  has a face inclined downward in a radial direction from a center of rotation, and a radial blade  313  is included. 
     The impeller cover  33  includes an air inlet  331  defined in an upper center portion thereof, which is a passage through which air moves, and is provided in a form inclined downward with respect to the air inlet  331 . A cover coupling portion  332  is provided at a lower end of the impeller cover  33 . The cover coupling portion  332  may be provided in a step shape, and the body coupling portion  15  may be fitted into the step-shaped cover coupling portion  332 . 
       FIG.  4    is an exploded perspective view of a motor according to one embodiment of the present disclosure. 
     Referring to  FIG.  4   , a motor of the present embodiment includes a stator and a rotor configured to rotate with respect to the stator. The stator may include a stator core  300  defining a back yoke, teeth  520  extending in a radial direction from the back yoke, a coil  510 , an insulator module  100  coupled to a top face of the stator core  300 , and a divided-core  500  inserted into the stator core  300  in an axial direction. 
     The teeth  520  extend radially inwardly (inner type) of the back yoke in the present embodiment. However, the present disclosure is not necessarily limited thereto. The teeth  520  may extend radially outwardly (outer type) of the back yoke. 
     The stator core is formed in a hollow cylindrical shape. Thus, the stator core defines an arc of the back yoke. As used herein, a radial and inward direction refers to a direction radially and inwardly of an arc of an inner face of the stator core or means a direction radially and inwardly of the back yoke. 
     In addition, in the present embodiment, a configuration is described in which a concentrated winding scheme around the teeth  520  is applied and a teeth-divided core is inserted into the stator core  300  in an axial direction (longitudinal direction) thereof. This configuration is employed because space constraint occurs due to a small size of the stator core  300  caused by the miniaturization of the motor and, thus, it is difficult to couple the teeth-divided core with the back yoke of the stator in a radial direction of the motor. 
     The insulator module  100  may be coupled to a top face of the stator core  300  and include terminal units  110  and  130  connected to lead wires  511  and  513  from the divided core  500 . An insulator body  150  of the insulator module  100  may have a predetermined height H for insulation of the lead wires  511  and  513  and insulation between the terminal units. 
     The terminal units  110  and  130  may be positioned at different vertical levels within the predetermined height H. The terminal units  110  and  130  may define different layer layers of the insulator module  100 . The layers defined by the terminal units  110  and  130  and the insulator body  150  may be combined with each other to form the insulator module  100 . A detailed structure thereof will be described later. 
     In one example, the insulator module  100  includes each power terminal unit  110  connected to each of 3-phases power lead wires of the coils  510 , a neutral terminal unit  130  connected to a neutral point of the coil  510 , and the insulator body  150  to achieve insulation between the stator core  300  and the terminal units  110  and  130  and between the terminal units  110  and  130 . 
     The insulator module  100  may be formed by insert injection molding the terminal units  110  and  130  and the insulator body  150 . However, the present disclosure is not necessarily limited thereto. As will be described below, the terminal units  110  and  130  and the insulator body  150  may be stacked on each other to form the insulator module  100 . That is, members defining layers respectively may be stacked on each other to form the insulator module  100 . 
     When the insulator module  100  is formed using the stacking scheme, the layers may be fixed to each other via various methods. In one example, grooves and protrusions are formed in and on the layers constituting the insulator module  100 , and then the protrusions may be press-fitted into the corresponding grooves, such that the layers may be fixed to each other. Alternatively, the layers may be fixed to each other by applying an adhesive to faces of the layers and bonding the layers to each other. 
     The power terminal units  110  and the neutral terminal unit  130  may be located at different vertical levels in the insulator body  150 . A spacing between the vertical levels of the terminal units  110  and  130  may be contained in the predetermined height H of the body  150  of the insulator module  100 . 
     In the present embodiment, the power terminal unit  110  is located at a top level of the body  150  of the insulator module  100 , while the neutral terminal unit  130  is located at a middle level of the body  150  of the insulator module  100 . In detail, the power terminal unit  110  may define a portion of a top face of the insulator module  100 , while the neutral terminal unit  130  may define a portion of an inner circumferential face of the insulator module  100 . 
     The predetermined height H may mean a vertical dimension to a top from a bottom of the body  150  of the insulator module  100 . The height H may be preferably defined as a vertical dimension of the insulator body  150 . However, the present disclosure may not be limited thereto. When the power terminal unit  110  protrudes from a top of the insulator module  100 , the height may include a vertical dimension from the bottom of the insulator module  100  to the top of the power terminal unit  110 . 
     Further, for example, while maintaining the relative difference between the vertical levels of the power terminal unit  110  and the neutral terminal unit  130 , the insulator body  150  may be configured to surround the top face  112   u  of a power connecting member as described later of the power terminal unit  110 . In this case, the predetermined height H means a vertical dimension from the bottom to the top of the insulator module  100 . The insulator body  150  may define a top layer and a bottom layer of the insulator module  100 . 
     In one example, as the insulator module  100  has the predetermined height H, this may realize insulation between the terminal units  110   m  and  130  and the stator core  300 . Further, the terminal units  110  and  130  are located at different vertical levels within the predetermined height H, so that the insulation between the terminal units  110  and  130  can be performed. 
     The stator core  300  may be formed in a cylindrical shape having inner space into which the divided-core  500  is inserted. Each of the inner circumferential face and the outer circumferential face of the stator core  300  may be partially flattened. 
     That is, planar faces  310   a  and  330   a  may be formed on the inner circumferential face and the outer circumferential face of the stator core  300 , respectively. 
     Due to the planar faces  310   a  and  330   a , the radial thickness of the stator core  300  may be reduced to reduce the overall size of the motor. Further, due to the planar faces  310   a  and  330   a , a portion that may act as a resisting portion against magnetic flux flowing through the stator core  300  may be reduced to improve the performance of the motor. 
     In one example, a shape of the body of the insulator module  100  may be a hollow cylindrical shape, which corresponds to the shape of the stator core  300 . Planar faces  150   a  may be formed at portions of the outer and inner circumferential faces of the insulator body  151  that are in contact with the planar faces  310   a  and  330   a  respectively. 
     In addition, at least one groove  331  may be defined in a portion of the inner circumferential face  330  of the stator core  300  along a circumference of the inner circumferential face  330 . A tooth  520  of the divided-core  500  may be engaged with the groove  331  in the axial direction (the longitudinal direction of the stator core). 
       FIG.  5 A  is a perspective view of a divided-core of  FIG.  4   .  FIG.  5 B  is a cross-sectional view taken along a line of a-a′ of  FIG.  5 A . 
     Referring to  FIGS.  5 A and  5 B , the divided-core  500  of the present embodiment is a teeth-divided core. Further, the divided-core  500  may be inserted into the stator core  300  along an axial direction perpendicular to the radial direction of the stator core  300 . 
     The core  500  may include an insulator  530  surrounding the tooth  520  and insulating the coil  510  from the tooth  520 . The insulator  530  surrounds outer faces of a wound portion  523  and a pole shoe  525  of the tooth  520  and defines a section in which the coil  510  is wound. As described above, the coil  510  may be wound around the tooth  520  in a concentrated winding manner. Further, the 3-phases power lead wires  511  may be drawn horizontally and outwardly of the divided-core  500  from a top portion of the core  500 . Further, the neutral-point lead wires  513  may be drawn horizontally from a top portion of the divided-core  500  and downwardly. 
     The motor of the present embodiment has a structure in which the divided-core  500  is inserted into the stator core  300  along the axial direction from a position below the stator core  300 , and the insulator module  100  is brought into contact with the top face of the stator core  300  in the axial direction. Thus, the 3-phases power lead wires  511  should be connected to the terminals on the insulator module  100 , while the neutral-point lead wires  513  should be connected to the terminals on the insulator module  100 . Therefore, the lead wires from the coil  510  may be preferably drawn out from a top portion of the divided-core  500 . 
     In one example, when the coil  510  is wound in a first direction D 1 , the coil  510  is wound radially and inwardly of the tooth  520 . The winding may begin in a clockwise or counterclockwise direction, downwardly of the tooth  520 . Then, the coil  520  may be wound upwardly of the tooth  520  and then connected to the terminal. 
     When the coil  510  is wound in a second direction D 2 , the coil  510  is wound radially and outwardly of the tooth  520 . The winding may begin in a clockwise or counterclockwise direction, downwardly of the tooth  520 . Then, the coil  520  may be wound upwardly of the tooth  520  and then connected to the terminal. 
     A top portion of the tooth  520  may mean a portion close to the insulator module  100 , and a bottom portion of the tooth  520  may mean an opposite portion to the top portion. 
     As a result, even when the coil  510  is wound in one of the first direction D 1  and the second direction D 2 , the 3-phases power lead wires  511  may be drawn horizontally and outwardly of the teeth  520  from the top portion of the core  500 . 
     The power terminal  113  to be described later is provided on the top face of the insulator module  100 . The neutral terminal  131  is disposed on an inner face of the insulator module  100 . Thus, the 3-phase power lead wires  511  and the neutral-point lead wires  513  may be connected to the terminals in the radial region of the back yoke, that is, in the radial region of the stator core  300 . 
     In one example, the tooth  520  may include a coupling portion  521  coupled to the groove  331  of the stator core  300 , the wound portion  523  extending from the coupling portion  521  in the radial direction of the back yoke, and the pole shoe  525  branching from the wound portion  523  and constituting a magnetic circuit. 
     The insulator  530  surrounds outer faces of a wound portion  523  and a pole shoe  525  of the tooth  520  and defines a section in which the coil  510  is wound. 
     The pole shoe  525  branches from the wound portion  523  and has a curved inner face along a virtual circumferential face inside the stator core  300 . Further, each of the neutral-point lead wires  513  may be connected to the terminal at a position between the inner circumferential face  330  of the stator core  300  and the virtual circumferential surface to ensure an insulation performance. 
       FIG.  6 A  is a perspective view of an insulator module of  FIG.  4   .  FIG.  6 B  shows a cross section view taken along a line of a-a′ of  FIG.  6 A . 
     Referring to  FIGS.  6 A and  6 B , as described above, the insulator module  100  may include the insulator body  150 . 
     Each power terminal unit  100  in accordance with the present embodiment includes a power terminal  113  protruding from the top of the body  150  within the radial region of the back yoke and connected to one of the 3-phase power lead wires  511  of the coil  510 , a connection terminal  111  connected to the power terminal  113  and connected to the one of the 3-phase power lead wires  511 , and a power connecting member  112  having one end connected to the power terminal  113  and the other end connected with the connection terminal  111 . 
     The power terminal  113  may include a power terminal body  1132  upwardly protruding from the insulator body  150  and a guide groove  1131  defined in the body  1131  to receive and guide one of the 3-phase power lead wires  511  of the coil  510 . 
     Each 3-phase power lead wires  511  may be fitted into the guide groove  1131 . Preferably, the groove  1131  may have a width smaller than a diameter of the 3-phase power lead wire  511 . Thus, the 3-phase power lead wire  511  may be press-fitted into the guide groove  1131 . 
     In one example, a bottom face of the guide groove  1131  may have a predetermined angle of inclination to guide each 3-phase power lead wire  511 . 
     The connection terminal  111  may be connected to each of the 3-phases power lead wires. Although not shown in the drawing, the connection terminal  111  is connected to a printed circuit board (PCB). The connection terminal  111  may be connected to the power terminal  113  via the power connecting member  112 . 
     The power connecting member  112  electrically and physically connects the power terminal  113  and the connection terminal  111  with each other. A top face  112   u  of the power connecting member  112  may define a portion of a top face of the insulator module  100 . A side face  112   s  of the power connecting member  112  may define a portion of the inner circumferential face of the insulator module  100 . 
     That is, the top face  112   u  of the power connecting member  112  may be located on the top face of the insulator body  150  of the insulator module  100 . The connection terminal  111  may extend upward from the top face  112   u . The side face  112   s  of the power connecting member  112  may be curved to correspond to the circular shape of the insulator body  150  of the insulator module  100  to define a portion of the inner circumferential face of the insulator module  100 . Thus, the power connecting member  112  may define a top portion of the insulator module  100 . 
     However, the top face  112   u  of the power connecting member  112  does not necessarily define the top face of the insulator module  100 . The insulator body  150  may be formed on the top face  112   u  of the power connecting member  112  such that the insulator body  150  may define a top face of the insulator module  100 . 
     The neutral terminal  131  protrudes radially and inwardly of the back yoke and may be disposed on an inner face of the insulator body  150  of the insulator module  100 . The neutral terminals  131  may be electrically and physically connected with each other via a neutral connecting member  132 . 
     The neutral connecting member  132  may be curved to correspond to the circular shape of the insulator body  150  of the insulator module  100  to define a portion of an inner face of the insulator module  100 . 
     The insulator body  150  of the present embodiment may be coupled to the top face of the stator core  300 , have the height H for securing the insulation distance from the stator core  300 , and have a predetermined thickness T in the radial direction. In addition, the insulator body  150  may be formed in a hollow cylindrical shape corresponding to the shape of the stator core  300 . 
     Referring to  FIG.  8   , each neutral terminal  131  may be formed in a hook shape, and may include an extension  1311  protruding inwardly of the insulator body  150  from the neutral connecting member  132  and a hook  1313  bent from one end of the extension  1311  toward an inner circumferential face of the lower insulator body  155 . However, the shape of the neutral terminal  131  is not limited to a structure only including the extension  1311  and the hook  1313 . Various shapes thereof configured such that the neutral terminal  131  is formed inside the lower insulator body  155  and is connected to each neutral-point lead wire  513  may be included herein. 
     The insulator body  150  may have the predetermined height H. The predetermined height H may correspond to a sum of a first height H 1  of an lower insulator body  151  and a second height H 2  of a upper insulator body  153 , which will be described later. 
     A height of the neutral terminal unit  130  may be smaller than the first height H 1 . A height of the power terminal unit  110  may be smaller than the second height H 2 . Thus, the insulation between the terminal units and insulation between the terminal units and the stator core  300  may be ensured. 
     Preferably, the power terminals  113  may be formed at the same vertical level in the insulator module  100 . The neutral terminals  131  may be formed at the same vertical level in the insulator module  100 . 
     In one example, the insulator body  150  may have the predetermined thickness T. The top face  112   u  of the power connecting member  112  may have a first thickness T 1  that is smaller than the thickness T. Therefore, the thickness T may correspond to a sum of the first thickness T 1  and a remaining thickness T 2  of the top face of the insulator body  150 . 
     That is, the terminal units  110  and  130  may be radially and vertically surrounded with the insulator body  150 . 
       FIG.  7    is a perspective view of a state in which a power terminal unit is separated from an insulator module.  FIG.  8    is a perspective view of a state in which a neutral terminal unit is separated from an insulator module. 
     Referring to  FIG.  7   , each power terminal unit  110  may be each of three separate members corresponding to three phases, respectively. In one power terminal unit  110   b , a connection terminal  111   b  and a power terminal  113   b  may be directly electrically and physically connected to each other without a power connecting member  112 . In the power terminal units  110   a  and  110   c  having the power connecting members  112   a  and  112   c , the power connecting members  112   a  and  112   c  may be curved at the same curvature. 
     Further, the power terminals  113   a ,  113   b , and  113   c  may be preferably spaced from each other at 120 degrees angular spacing. Each three-phase power lead wire  511  may be connected to each of the power terminals without bending thereof while passing through the radial thickness of the back yoke or insulator. 
     In one example, a receiving groove  1523  may be defined in a top face of the insulator body  150  of insulator module  100  to allow each of the power terminal units  110   a ,  110   b , and  110   c  to be seated thereon respectively. The receiving grooves  1523   a ,  1523   b , and  1523   c  may correspond to the power terminals respectively. The receiving groove  1523   a ,  1523   b , and  1523   c  may be spaced from each other at a predetermined spacing. Thus, an insulator portion may act as the insulating spacing. 
     Referring to  FIG.  8   , the neutral terminal unit  130  may include a neutral connecting member  132  curved along the inner circumferential face of the insulator body  150  of the insulator module  100 . The neutral connecting member  132  may have a third thickness T 3  that is smaller than a predetermined thickness T of the insulator body  150  of the insulator module  100 . Preferably, the third thickness T 3  may be the same thickness as the first thickness T 1 . 
     In one example, a receiving groove  152  in which the member  132  of the neutral terminal unit  130  is seated may be formed in the inner circumferential face of the insulator body  150  of the insulator module  100 . 
       FIG.  9    is an exploded perspective view of an insulator module. Referring to  FIG.  9   , the insulator body  150  may include a lower insulator body  151  positioned above the stator core  300  to insulate between the stator core  300  and the neutral terminal unit  130 , and an upper insulator body  153  positioned on a top face of the lower insulator body  151  to insulate between the neutral terminal unit  130  and the power terminal unit  110 . 
     The lower insulator body  151  may have a first face  1511  in contact with the top of the stator core  300  and a second face  1512  in which a receiving groove  1521  is formed for receiving the neutral terminal unit  130  therein. The upper insulator body  153  has a third surface  1533  in which a receiving groove  1522  in which the neutral terminal unit  130  is seated, the third surface  1533  being in contact with the second surface  1512 , and a fourth surface  1534  in which a receiving groove  1523  is formed, in which the power terminal unit  110  is seated. 
     Each of the upper insulator body  151  and the lower insulator body  153  has a predetermined thickness T. The lower insulator body  151  and the upper insulator body  153  are stacked to define the predetermined height H. 
     That is, each of the lower insulator body  151  and upper insulator body  153  has the same thickness as the thickness T of the insulator module  100  and has a flat surface on each of an inner circumferential face and outer circumferential face thereof. When the sum of the first height H 1  of the lower insulator body and the second height H 2  of the upper insulator body corresponds to the predetermined height H, when the lower insulator body  151  and the upper insulator body  153  are stacked on each other. 
     The lower insulator body  151  extends from the first face  1511  to the second surface  1512  to form the first height H 1 . The lower insulator body  151  at a vertical level in which the receiving groove  1521  is formed may have a fourth thickness T 4 . The receiving groove  1521  may receive the neutral terminal unit  130  therein. The neutral terminal unit  130  may have a third thickness T 3  such that the sum of the third thickness T 3  and the fourth thickness T 4  is equal to the thickness T from the inner circumferential face to the outer circumferential face of the lower insulator body  151 . 
     That is, the lower portion of the neutral terminal unit  130  may be surrounded with the lower insulator body  151 . 
     The upper insulator body  153  extends from the third face  1533  to the fourth surface  1534  to define the second height H 2 . A receiving groove  1522  in which the neutral terminal unit  130  rests may be defined in the third face  1533 . A receiving groove  1523  in which the power terminal unit  110  is seated may be formed in the fourth surface  1534 . 
     Thus, the receiving groove  1522  may be defined in the third face  1533  and the second face  1512  and may receive the neutral terminal unit  130  therein. The thickness of the portion in which the receiving groove  1522  is formed in the third face  1533  may be the same as the fourth thickness T 4 . 
     In addition, the third face  1533  and the fourth face  1534  are spaced apart by a predetermined vertical dimension so that the lower insulator body  153  has the second height H 2 . The sum of the depths of the receiving groove  1522  formed in the third face  1533  and the receiving groove  1523  formed in the fourth face  1534  may be smaller than the predetermined vertical dimension. 
     That is, to perform insulation between the neutral terminal unit  130  and the power terminal unit  110  seated in the receiving grooves  1522  and  1523  respectively, the sum of the depths of the receiving grooves formed in the upper and lower portions of the upper insulator body  153  respectively may be preferably smaller than the entire height of the upper insulator body  153 . 
     In one example, the thickness of the portion of the upper body  153  at the level at which the receiving groove  1523  in which the power terminal unit  110  is accommodated is a second thickness T 2 . The power connecting member  112  has a first thickness T 1  such that the sum of the second thickness T 2  and the first thickness T 1  is equal to the thickness T from the inner circumferential face to the outer circumferential face of the upper insulator body  153 . 
     In the above-described embodiment, the layers forming the insulator module  100  may be stacked on each other. However, the present disclosure is not necessarily limited to the stacking method. The insulator module may be formed via an insert injection molding. 
       FIG.  10    is a perspective view of a motor according to an embodiment of the present disclosure. 
     Referring to  FIG.  10   , the divided-core  500  in the present embodiment may be inserted into the stator core  300  and be connected to the insulator module  100 . The divided-core  500  may be inserted into the stator core  300  in the axial direction from below the stator core  300 . The insulator module  100  may be brought into contact with the top face of the stator core  300  along the axial direction from above the stator core  300 . 
     The insulator module  100  has the predetermined height H. The height H may mean the vertical dimension from a bottom face in contact with the top face of the stator core  300  to the top face of the insulator module  100 . In this embodiment, the power connecting member  112  may define a portion of the top face of the insulator module  100 . 
     The coils  510  are drawn horizontally from the top of the teeth  520  toward the inner face of the back yoke while being received in a groove  531  formed in a top face of the insulator  530 . Then, the 3-phase power lead wires  511  of the coils may be connected to the power terminals  113 . Three power terminals  113  corresponding to the 3-phases may be spaced from each other at a 120 degrees angular spacing. At least two of the power terminals  113  corresponding to the 3-phases may be electrically connected to the connection terminals  111  via the power connecting members  112  respectively. 
     The coils  510  are drawn horizontally from the top of the teeth  520 . Then, the neutral-point lead wires  513  may be bent downwardly and connected to the neutral terminals  131 . The neutral terminal  131  may include the extension  1313  extending radially and inwardly of the back yoke from the neutral connecting member  132  and the hook  1311  bent from the extension  1313 . The extension  1313  may extend radially and inwardly of the back yoke to be insulated from the coil  510 . The hook  1311  is preferably bent in a region corresponding to an adjacent tooth of the divided teeth. Accordingly, each of the neutral-point lead wires  513  may be connected to the hook  1311  to secure the insulation distance from the coil  510  located inside the stator core  300 . 
     As a result, each of the 3-phases power lead wires  511  may be connected to each terminal within a radial region of the back yoke. Since the insulator module  100  has the predetermined thickness T corresponding to the radial dimension of the back yoke, the 3-phases power lead wires  511  may be connected to the power terminals  113  within the thickness T. 
     Further, each of the neutral-point lead wires  513  may also be connected with each terminal within the radial region of the back yoke. In detail, the insulator module  100  has the predetermined height H and is present above the stator core  300  and is formed in the shape corresponding to the cylindrical shape of the stator core  300 , each of the neutral-point lead wires  513  may be connected with each terminal inside the insulator module  100 , that is, may be connected to each neutral terminals  131  present in the height H. 
     That is, the connection points between the both lead wires  511  and  513  and the terminals may be present within the radial region of the back yoke. Thus, the insulation performance may be ensured. Further, at the same time, the structural position between the terminal units  110  and  130  according to the thickness T and the height H of the insulator module  100  may improve the insulation performance. Therefore, an outer diameter of the stator may be reduced and thus a radial thickness of the back yoke may be reduced, so that miniaturization and lightening of the motor may be implemented, and at the same time, insulation performance between the terminal units  110  and  130  may be secured. 
     Although the present disclosure has been described with reference to the preferred embodiments of the present disclosure, those skilled in the art may understand that the present disclosure may be variously modified and changed without departing from the spirit and scope of the present disclosure as described in the claims below.