Patent Description:
A motor is a device that converts electrical energy into mechanical energy. The motor generally includes a stator and a rotor rotatably disposed with a predetermined gap (e.g., air gap) with respect to the stator. The size and weight of the motor vary depending on an intended use.

Some motors include a motor assembly having an impeller to generate a pressure during rotation or to promote the movement of air. However, in a motor assembly having an impeller, the air volume may be reduced if the sizes of the stator and the rotor are reduced.

In a motor assembly having an impeller, when the sizes of the stator and the rotor are reduced, a method of increasing the number of rotations of the rotor may be used to maintain the air volume. However, when the number of rotations of the impeller and the rotor is increased, a temperature of the stator and the rotor may be excessively increased.

In addition, when the number of rotations of the impeller and the rotor is increased, the amount of displacement of a bearing that supports a rotating shaft increases as much, thereby shortening the life of the bearing.

In addition, when the number of rotations of the impeller and the rotor is increased, the bearing strength for supporting the rotating shaft of the rotor is further reduced due to the size reduction of the stator and the rotor, thereby increasing the wear of the bearing.

In addition, if a portion of the air passing through the impeller is moved toward the stator and the rotor to cool the stator and the rotor, the air flow resistance may increase, thereby degrading power and efficiency of the motor.

<CIT> relates to a fan motor suitable for high-speed rotation of a fan. This fan motor comprises an impeller, a first and a second diffuser, an impeller cover and a motor. The fan motor further comprises a communication portion provided at the hub of the second diffuser.

The present disclosure describes a motor assembly capable of discharging heated air to the outside of a diffuser.

The present disclosure also describes a motor assembly capable of restricting the occurrence of vibration of a bearing.

The present disclosure also describes a motor assembly capable of accelerating cooling of a bearing.

The present disclosure also describes a motor assembly capable of increasing a heat exchange area of a bearing.

In order to achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a motor assembly comprising the features of the attached claim <NUM>.

According to this configuration, an air flow path having a relatively low pressure is provided between the inside of the impeller cover and the outside of the hub of the second diffuser. As a result, the air inside the hub of the second diffuser, which has a relatively high pressure, is quickly moved to the air flow path through the communicating portion and contacts the motor inside the hub to form an air current moved toward the communicating portion, thereby accelerating cooling of the motor. In addition, the motor maintains a relatively low temperature during operation, so that adverse effects due to high temperature may be reduced.

The first diffuser may be configured to include a hub and a plurality of blades provided around the hub. Because the first diffuser does not have an outer wall at an outer end of the plurality of blades in a radial direction, a mold for forming the plurality of blades may enable an access of the first diffuser in the radial direction, thereby facilitating manufacturing of the first diffuser.

In general, when a temperature of the motor is high, electrical resistance of a stator coil may increase to reduce power. However, in some implementations, the motor maintains a relatively low temperature during operation, and thus the increase in the electrical resistance of the stator coil may be restricted and power (e.g., output) may be enhanced.

The second diffuser has a bearing accommodating portion in which a bearing supporting the rotating shaft of the motor is accommodated. Therefore, cooling of the bearing is promoted.

In addition, the second diffuser may be made of a material having a thermal conductivity superior to the first diffuser. Accordingly, heat dissipation of the second diffuser may be promoted, and cooling of the bearing may be further promoted.

In order to achieve these and other advantages and in accordance with the purpose of this specification, as embodied and broadly described herein, there is provided a motor assembly including an impeller, a first diffuser disposed at a downstream side of the impeller, a second diffuser provided at a downstream side of the first diffuser, an impeller cover coupled to the second diffuser so that the impeller and the first diffuser are accommodated therein, and a motor provided at the downstream side of the second diffuser to drive the impeller. The second diffuser includes a hub, an outer wall concentrically disposed outside the hub, and a plurality of blades having one side connected to the hub and the other side connected to the outer wall. The impeller cover is coupled to the outer wall of the second diffuser. A communicating portion, which is configured to allow fluid communication between the inside and the outside of the hub of the second diffuser, is provided at the hub of the second diffuser.

Accordingly, air between the second diffuser and the motor may be discharged to the outside of the second diffuser through the communicating portion.

According to this configuration, the air heated by the motor during operation may be discharged to the outside of the second diffuser through the communicating portion, so that cooling of the motor may be promoted.

Because the impeller cover is coupled to the outer wall of the second diffuser, an air flow path with a relatively low pressure may be provided outside the hub of the second diffuser. Therefore, the air inside the hub of the second diffuser with relatively high pressure may be rapidly moved to the air flow path through the communicating portion, thereby promoting cooling of the motor.

In addition, the motor may maintain a relatively low temperature during operation, so that adverse effects due to high temperature may be reduced.

In general, when the temperature of the motor is high, electrical resistance of a stator coil may increase to thereby degrade power. However, in some implementations, the motor maintains a relatively low temperature during operation, and thus the increase in the electrical resistance of the stator coil may be restricted to improve power.

In addition, because the first diffuser and the second diffuser may be separately manufactured, the manufacturing of the diffusers may be facilitated. For example, in the first diffuser, a plurality of blades are provided around the hub and an outer wall is not provided outside the plurality of blades of the first diffuser. Therefore, the manufacturing of the first diffuser may be facilitated.

In an implementation of the present disclosure, the first diffuser includes a tubular hub having one side open along the axial direction and a plurality of blades provided at an outer wall of the hub. The hub of the second diffuser is inserted and coupled to the inside of the first diffuser so as to be in surface contact with the hub of the first diffuser. Accordingly, a coupling force between the first diffuser and the second diffuser may be improved.

According to the configuration, when an external force is applied to the first diffuser and the second diffuser, deformation of the first diffuser and the second diffuser may be restricted.

In an implementation of the present disclosure, the impeller includes a hub and a plurality of blades protruding radially around the hub and spaced apart from each other in a circumferential direction. The impeller may have a conical shape. The impeller may be configured to gradually increase in an outer diameter from an upstream end toward a downstream end.

According to the present invention, the hub of the second diffuser includes a bearing accommodating portion.

As a result, a bearing strength may be improved by the hub of the first diffuser that is coupled to the bearing accommodating portion to be in surface contact with each other. Therefore, the occurrence of deformation may be restricted.

In an implementation of the present disclosure, the second diffuser is made of a material having thermal conductivity superior to the first diffuser. Therefore, cooling of the bearing accommodating portion and the bearing may be promoted.

In an implementation of the present disclosure, the first diffuser may be made of a synthetic resin member, and the second diffuser may be made of a metal member. For example, the second diffuser may be formed of an aluminum member. Therefore, cooling of the bearing accommodating portion and the bearing may be further promoted.

In an implementation of the present disclosure, the second diffuser includes a heat dissipation fin protruding to increase a surface area. Therefore, cooling of the bearing may be further promoted.

In an implementation of the present disclosure, the heat dissipation fin includes a radial heat dissipation fin having one end connected to the circumference of the bearing accommodating portion and the other end disposed in a radial direction. Therefore, heat dissipation of thermal energy of the bearing accommodating portion may be promoted through the radial heat dissipation fin.

In addition, one end of the bearing accommodating portion may be supported by the radial heat dissipation fin connected to the circumference of the bearing accommodating portion, so that the bearing strength of the bearing accommodating portion may be improved.

According to this configuration, the occurrence of vibration and displacement of the bearing provided inside the bearing accommodating portion may be restricted. Therefore, the occurrence of wear of the bearing may be restricted.

In an implementation of the present disclosure, the heat dissipation fin include a circumferential heat dissipation fin disposed along a circumferential direction on an inner surface of the hub of the second diffuser. Accordingly, rigidity of the hub of the second diffuser may be improved.

According to this configuration, the occurrence of vibration and displacement of the bearing provided in the bearing accommodating portion may be restricted, so that the occurrence of wear of the bearing may be restricted.

In addition, heat dissipation of the thermal energy of the bearing accommodating portion may be promoted, so that cooling of the bearing provided in the bearing accommodating portion may be promoted.

In an implementation of the present disclosure, the motor includes a stator and a rotor rotatably disposed inside the stator, and the hub of the second diffuser includes a stator coupling portion coupled to the stator. Accordingly, a coupling force between the stator and the second diffuser may be stably provided.

In an implementation of the present disclosure, the stator coupling portion is provided in plurality and the plurality of stator coupling portions are spaced apart from each other along the circumferential direction of the stator. Accordingly, the coupling force between the stator and the second diffuser may be increased.

For example, the stator coupling portion may include an outer circumferential surface contact portion in surface contact with the outer circumferential surface of the stator. Accordingly, the coupling state of the stator and the second diffuser may be more stably maintained.

In an implementation of the present disclosure, the stator coupling portion may include an end surface contact portion in surface contact with one end of the stator along the axial direction. Accordingly, the occurrence of axial gap between the stator and the second diffuser may be restricted.

In an implementation of the present disclosure, the stator coupling portion includes a radial section having one end connected to the bearing accommodating portion and the other end extending in a radial direction. Therefore, rigidity of the bearing accommodating portion may be further improved.

In an implementation of the present disclosure, the stator coupling portion has an axial section extending in the axial direction from the radial section, and the outer circumferential surface contact portion is provided on an inner surface of the axial section. Accordingly, the coupling force between the second diffuser and the stator may be further improved.

In an implementation of the present disclosure, the end surface contact portion is provided in the axial section to further protrude inward along the radial direction compared to the outer circumferential surface contact portion. Accordingly, the bearing accommodating portion of the second diffuser is spaced apart from the end of the stator by a preset distance.

According to this configuration, a temperature rise of the bearing accommodating portion and the bearing due to heat generation of the stator coil may be restricted.

In an implementation of the present disclosure, the second diffuser is configured to include the stator coupling portion and the heat dissipation fin. Accordingly, the rigidity of the second diffuser may be improved, and the heat dissipation area may be increased.

In some implementations, the stator coupling portion is configured to have a relatively large size compared to the heat dissipation fin. For example, a width of the stator coupling portion along the circumferential direction is significantly larger than a width of the heat dissipation fin along the circumferential direction.

In addition, the height (or width) of the stator coupling portion along the axial direction is the same as the height (or width) of the heat dissipation fin along the axial direction. Alternatively, the height (or width) of the stator coupling portion along the axial direction is larger than the height (or width) of the heat dissipation fin along the axial direction.

The stator coupling portion may be implemented as three stator coupling portions, and the radial heat dissipation fin may be respectively provided between the radial sections of the stator coupling portions adjacent to each other along the circumferential direction.

The circumferential heat dissipation fin may be respectively provided between radial sections of the stator coupling portions adjacent to each other along the circumferential direction.

The radial heat dissipation fin may be connected by the circumferential heat dissipation fin.

With this configuration, the rigidity of the second diffuser may be remarkably improved. In addition, the heat dissipation area of the second diffuser may be remarkably increased.

In an implementation of the present disclosure, the first diffuser and the second diffuser have fastening member insertion holes penetrated along the axial direction so that a fastening member may be inserted, respectively. For example, a fastening member is coupled to the hub of the first diffuser and the hub of the second diffuser that are coupled to be in surface contact with each other, so that the hub of the first diffuser and the hub of the second diffuser are integrally coupled. Accordingly, the coupling force between the first diffuser and the second diffuser may be further improved.

In an implementation of the present disclosure, two blades adjacent to each other in the circumferential direction, among the plurality of blades of the second diffuser, are disposed such that an upstream end and a downstream end are spaced apart from each other in the circumferential direction.

For example, upstream ends of the plurality of blades of the first diffuser are arranged to be spaced apart from each other at a predetermined distance along the circumferential direction of the first diffuser, and the downstream ends of the plurality of blades extend along the circumferential direction of the first diffuser to be inclined with respect to the axial direction.

Therefore, each downstream end of the plurality of blades is arranged to overlap the upstream end of the other adjacent blade by a preset length. Further, a flow rate of the air moved by the impeller may be reduced and a static pressure may be increased.

In an implementation of the present disclosure, the plurality of blades of the second diffuser have an upstream end and a downstream end adjacent to each other, among the two blades adjacent to each other in the circumferential direction, to be spaced apart from each other in the circumferential direction.

For example, the upstream ends of the plurality of blades of the second diffuser are spaced apart from each other at preset intervals along the circumferential direction of the second diffuser, and each downstream end of the plurality of blades extends along the circumferential direction to be inclined with respect to the axial direction.

For example, the axial length of the second diffuser is shorter than the axial length of the first diffuser, and the downstream ends of two adjacent blades among the plurality of blades of the second diffuser and upstream ends of the other adjacent blades are spaced apart from each other along the circumferential direction.

According to this configuration, because the plurality of blades of the second diffuser do not overlap, manufacturing may be facilitated.

In an implementation of the present disclosure, the length of the blade of the second diffuser is shorter than the length of the blade of the first diffuser.

In an implementation of the present disclosure, the impeller cover includes an impeller accommodating portion in which the impeller is accommodated, a suction portion extending in the axial direction from an upstream end of the impeller accommodating portion and suctioning air, and a first diffuser accommodating portion extending in the axial direction from a downstream end of the impeller accommodating portion and accommodating the first diffuser. As a result, an air flow path communicating with each other is provided between the inside of the impeller cover and the impeller and between the impeller cover and the first diffuser.

In some implementations, the impeller accommodating portion has a conical shape to correspond to a shape of the impeller, and the suction portion and the first diffuser accommodating portion have a cylindrical shape.

In an implementation of the present disclosure, an outer end of the blade of the first diffuser along the radial direction is disposed to face an inner circumferential surface of the first diffuser accommodating portion.

In an implementation of the present disclosure, the outer end of the blade of the first diffuser along the radial direction is disposed to be in contact with the inner circumferential surface of the first diffuser accommodating portion.

Accordingly, it is possible to restrict the occurrence of a flow loss of air moved between the plurality of blades of the first diffuser and the impeller cover by the impeller.

In an implementation of the present disclosure, the hub of the first diffuser includes a through portion penetrating along the axial direction, and the hub of the second diffuser includes a protrusion that protrudes along the axial direction and is inserted into the through portion. Accordingly, the hub of the first diffuser and the hub of the second diffuser overlap in the axial direction, thereby reducing an axial length of the diffuser.

In an implementation of the present disclosure, an anti-rotation protrusion protruding in the axial direction is provided at one of the mutual contact surfaces of the hub of the first diffuser and the hub of the second diffuser, and an anti-rotation protrusion accommodating recess accommodating the anti-rotation protrusion is provided at the other of the mutual contact surfaces. Accordingly, the first diffuser and the second diffuser may be assembled at an accurate position. In addition, the occurrence of a gap of the first diffuser and the second diffuser in the circumferential direction may be restricted.

In an implementation of the present disclosure, a bearing accommodating portion in which a bearing is accommodated is provided at a rear surface of the protrusion of the second diffuser.

In an implementation of the present disclosure, the communicating portion is provided between the blade of the first diffuser and the blade of the second diffuser along the axial direction.

For example, the hub of the second diffuser is configured to protrude from the hub of the first diffuser along the axial direction, and the plurality of blades of the first diffuser and the plurality of blades of the second diffuser are spaced apart from each other by a preset length along the axial direction.

Further, the communicating portion may be provided through a lower side of the downstream end of the hub of the first diffuser.

The communicating portion may be provided at the downstream side of the plurality of blades of the first diffuser.

The communicating portion may be provided at the upstream side of the plurality of blades of the second diffuser.

Therefore, lowering of suction power (or suction efficiency) of the impeller due to the formation of the communicating portion may be restricted.

In an implementation of the present disclosure, the communicating portion is implemented in plurality, which are spaced apart from each other along the circumferential direction of the diffuser. For example, the communicating portion is implemented as <NUM> to <NUM> pieces.

In an implementation of the present disclosure, the hub of the second diffuser includes a cylindrical portion and a disk portion disposed to block one end of the cylindrical portion. The disk portion may be provided at an upstream end of the cylindrical portion based on a moving direction of the air moved by the impeller.

In an implementation of the present disclosure, the communicating portion includes (i) a radial section having one side opened to the inside of the disk portion of the second diffuser and the other side extending to the outside of the cylindrical portion along the radial direction of the disk portion and (ii) an axial section having one side communicating with the radial section and the other side extending along the axial direction. Therefore, the extraction of air from the center of the upstream end of the motor may be facilitated.

For example, the axial section of the communicating portion may be configured to include a first axial section communicating with the radial section and recessed in the outer surface of the second diffuser.

The axial section of the communicating portion may be configured to include a second axial section communicating with the radial section and recessed in the inner surface of the hub of the first diffuser.

In an implementation of the present disclosure, the axial section may be configured to include (i) a first axial section recessed in the outer surface of the second diffuser and being in fluid communication with the first axial section and (ii) a second axial section being in fluid communication with the radial section and recessed in the inner surface of the hub of the diffuser.

Further, the first axial section and the second axial section may be configured to form a flow path through which air is moved cooperatively.

Accordingly, an increase in the thickness of the hub of the first diffuser and/or the hub of the second diffuser due to the formation of the axial section may be restricted.

In an implementation of the present disclosure, the second diffuser includes a bracket coupling portion to which a bracket is coupled.

Further, the bracket is configured to include (i) a bearing accommodating portion in which a bearing is accommodated and (ii) a plurality of leg portions having one end connected to the bearing accommodating portion and the other end curved and disposed along the axial direction.

A bearing, which is disposed at the downstream side of the rotor based on the moving direction of the air moved by the impeller, may be accommodated in the bearing accommodating portion of the bracket.

The plurality of leg portions of the bracket may be configured to be in contact with the ends of the stator coupling portions of the second diffuser, respectively.

The plurality of leg portions may be integrally coupled to the stator coupling portion by a fastening member.

The stator coupling portion may include a fastening member coupling portion to which the fastening member is screwed.

A fastening member insertion portion for allowing the fastening member to be inserted therein may be disposed to penetrate along the axial direction in the plurality of leg portions.

Hereinafter, implementations of the present disclosure will be described in detail with reference to the accompanying drawings. For the sake of brief description with reference to the drawings, the same or equivalent components will be provided with the same reference numbers, and description thereof will not be repeated. A singular representation used herein may include a plural representation unless it represents a definitely different meaning from the context. In describing the present disclosure, if a detailed explanation for a related known function or construction is considered to unnecessarily divert the gist of the present disclosure, such explanation has been omitted but would be understood by those skilled in the art. The accompanying drawings are used to help easily understand the technical idea of the present disclosure and it should be understood that the idea of the present disclosure is not limited by the accompanying drawings.

<FIG> is a perspective view of a motor assembly according to an implementation of the present disclosure, <FIG> is a cross-sectional view of the motor assembly of <FIG>, and <FIG> is an exploded perspective view of the motor assembly of <FIG>. As shown in <FIG>, a motor assembly <NUM> according to an implementation of the present disclosure includes an impeller cover <NUM>, an impeller <NUM>, a first diffuser <NUM>, a second diffuser <NUM>, and a motor <NUM>.

The impeller cover <NUM>, the impeller <NUM>, the first diffuser <NUM>, the second diffuser <NUM>, and the motor <NUM> are coupled along an axial direction.

The axial direction may refer to a direction parallel to a rotating shaft <NUM> of the motor <NUM>. In <FIG> and <FIG>, the axial direction coincides with a vertical direction.

For example, the first diffuser <NUM> is coupled to one side (e.g., a lower side in the drawing) of the impeller <NUM> along the axial direction, and the second diffuser <NUM> is coupled to one side (e.g., a lower side in the drawing) of the first diffuser <NUM>.

Between the impeller cover <NUM>, the first diffuser <NUM>, and the second diffuser <NUM>, an air flow path Pa through which air introduced by the rotation of the impeller <NUM> moves is provided.

The motor <NUM> is coupled to one side (e.g., a lower side in the drawing) of the second diffuser <NUM> along the axial direction.

The impeller <NUM> and the first diffuser <NUM> are accommodated inside the impeller cover <NUM>.

The impeller cover <NUM> is coupled to the second diffuser <NUM>.

When the impeller <NUM> rotates, air is sucked into the impeller cover <NUM> and moves via the first diffuser <NUM> and the second diffuser <NUM>. The air passing through the second diffuser <NUM> is moved along the axial direction radially outward of the motor <NUM>.

In some implementations, the impeller <NUM> includes a hub <NUM> and a plurality of blades <NUM> disposed in a circumferential direction around the hub <NUM>.

The impeller <NUM> may be configured to rotate in a counterclockwise direction, for example, in the view of <FIG>.

The hub <NUM> of the impeller <NUM> has, for example, a conical cross-section.

A rotating shaft hole <NUM> is provided in the center of the hub <NUM> of the impeller <NUM> so that a rotating shaft <NUM> of the motor <NUM> may be inserted.

The impeller cover <NUM> is coupled to the outside of the impeller <NUM>.

The impeller <NUM> is rotatably accommodated inside the impeller cover <NUM>.

When the impeller <NUM> rotates, air is sucked in from the front (e.g., an upper side in the drawing) of the impeller cover <NUM> and discharged to the rear (e.g., a lower side in the drawing).

The front (e.g., an upper side in the drawing) of the impeller cover <NUM> through which air is sucked based on the moving direction of the air moved during rotation of the impeller <NUM> is referred to as an 'upstream side', and the rear (e.g., a lower side) of the impeller cover <NUM> from which the air is discharged may be referred to as a 'downstream side'.

A suction port <NUM> through which air is sucked is provided in the center of the impeller cover <NUM>.

The impeller cover <NUM> includes an impeller accommodating portion <NUM> accommodating the impeller <NUM> and a first diffuser accommodating portion <NUM> accommodating the first diffuser <NUM>.

The impeller accommodating portion <NUM> is implemented in a conical shape to correspond to the shape of the impeller <NUM>.

The impeller cover <NUM> has a suction portion <NUM> through which air is sucked.

The suction portion <NUM> may be disposed to extend along the axial direction from the upstream end of the impeller accommodating portion <NUM>.

The suction port <NUM> is disposed inside the suction portion <NUM> to penetrate along the axial direction.

An inner surface of the suction portion <NUM> may be implemented, for example, in a circular arc cross-sectional shape in which the center is convex inward.

The first diffuser accommodating portion <NUM> extends along the axial direction from the downstream end of the impeller accommodating portion <NUM>.

The suction portion <NUM> is implemented in a cylindrical shape having the same outer diameter though a length of the suction portion <NUM>.

The impeller accommodating portion <NUM> is implemented in a conical cross-sectional shape in which the outer diameter is gradually enlarged.

The first diffuser accommodating portion <NUM> is implemented in a cylindrical shape having the same outer diameter though a length of the first diffuser accommodating portion <NUM>.

For example, the downstream end of the impeller cover <NUM> is coupled to the upstream end of the second diffuser <NUM>.

An insertion portion <NUM> is provided at the downstream end of the impeller cover <NUM> so that the upstream end of the second diffuser <NUM> may be inserted.

The insertion portion <NUM> is cut to extend along the radial direction on the inner surface of the impeller cover <NUM>.

The upstream end of the second diffuser <NUM> is in contact with the insertion portion <NUM> along the axial direction.

Accordingly, an axial movement of the impeller cover <NUM> and the second diffuser <NUM> may be restricted.

An outer circumference of the insertion portion <NUM> is disposed radially outside the outer wall <NUM> of the second diffuser <NUM>, which will be described later.

The first diffuser <NUM> is disposed on one side (e.g., a lower side or a downstream side in the drawing) of the impeller <NUM> along the axial direction.

The first diffuser <NUM> is disposed to be spaced apart by a preset width along the axial direction so that the impeller <NUM> may be rotated.

The second diffuser <NUM> is coupled to one side (e.g., a lower side in the drawing) of the first diffuser <NUM>.

The first diffuser <NUM> includes a hub <NUM> and a plurality of blades <NUM> arranged in a circumferential direction around the hub <NUM>.

The first diffuser <NUM> is installed inside the impeller cover <NUM> so that the outer ends of the plurality of blades <NUM> face the inner circumferential surface of the first diffuser accommodating portion <NUM>.

In some implementations, the outer ends of the plurality of blades <NUM> of the first diffuser <NUM> are configured to contact the inner circumferential surface of the first diffuser accommodating portion <NUM>.

Accordingly, the occurrence of flow loss of the air sucked into the impeller cover <NUM> by the rotation of the impeller <NUM> may be restricted.

The second diffuser <NUM> includes a hub <NUM>, an outer wall <NUM> concentrically disposed around the hub <NUM>, a plurality of blades <NUM> having one end connected to the hub <NUM> and the other end connected to the outer wall <NUM>.

The outer wall <NUM> is provided outside the downstream end of the hub <NUM> of the second diffuser <NUM>.

For example, the outer wall <NUM> is concentrically disposed to be spaced apart from the outer circumference of the downstream end of the hub <NUM> of the second diffuser <NUM> by a predetermined distance.

A region (e.g., an upper region in the drawing) of the second diffuser <NUM> is inserted into and coupled to the inside of the first diffuser <NUM>. Another region (e.g., a lower region in the drawing) of the second diffuser <NUM> protrudes to the outside of the first diffuser <NUM>.

For example, the hub <NUM> of the second diffuser <NUM> is inserted and coupled to the inside of the hub <NUM> of the first diffuser <NUM>.

The outer wall <NUM> of the second diffuser <NUM> is exposed to the outside of the first diffuser <NUM>.

The impeller cover <NUM> is coupled to the outer wall <NUM> of the second diffuser <NUM>.

The upstream end of the outer wall <NUM> of the second diffuser <NUM> is in contact with the end of the insertion portion <NUM> of the impeller cover <NUM> along the axial direction.

A region (e.g., an upper region in the drawing) of the motor <NUM> is inserted and coupled to the inside of the second diffuser <NUM> along the axial direction.

The motor <NUM> includes a stator <NUM> and a rotor <NUM> rotatable with respect to the stator <NUM>.

The stator <NUM> includes, for example, a stator core <NUM> and a stator coil <NUM> wound around the stator core <NUM>.

A rotor accommodating hole <NUM> in which the rotor <NUM> is rotatably accommodated with a predetermined air gap (G) is disposed in the stator core <NUM>.

The rotor accommodating hole <NUM> is disposed to penetrate along the axial direction.

A plurality of teeth <NUM> and slots <NUM> are alternately disposed around the rotor accommodating hole <NUM> along the circumferential direction.

The stator core <NUM> is disposed by insulating and stacking a plurality of electrical steel sheets <NUM> each having the rotor accommodating hole <NUM>, a plurality of slots <NUM>, and teeth <NUM>.

An insulator <NUM> for insulating the stator coil <NUM> is provided in the stator core <NUM>. The insulator <NUM> may be configured to be coupled to contact each other on both sides of the stator core <NUM> along the axial direction, for example.

The rotor <NUM> includes, for example, a rotating shaft <NUM> and a permanent magnet <NUM> that is configured to rotate about the rotating shaft <NUM>.

The permanent magnet <NUM> is implemented in a cylindrical shape.

A rotating shaft hole <NUM> is disposed through the center of the permanent magnet <NUM> so that the rotating shaft <NUM> may be inserted.

The rotating shaft <NUM> is rotatably supported by a bearing <NUM>.

The bearing <NUM> may be disposed on both sides of the permanent magnet <NUM> along the axial direction.

The bearing <NUM> may be implemented as, for example, a ball bearing.

For example, the bearing <NUM> includes an outer ring, an inner ring concentrically disposed inside the outer ring, and a plurality of balls disposed between the outer ring and the inner ring.

The bearing <NUM> includes, for example, a first bearing 310a provided between the impeller <NUM> and the rotor <NUM> and a second bearing 310b spaced apart from the first bearing 310a along the axial direction.

In some implementations, the first bearing 310a has a larger size than the second bearing 310b. For example, the outer ring <NUM>, the inner ring <NUM>, and the ball <NUM> of the first bearing 310a are larger than the outer ring <NUM>, the inner ring <NUM> and the ball <NUM> of the second bearing 310b, respectively. Accordingly, the impeller <NUM> and the rotor <NUM> may be stably supported.

A bracket <NUM> is coupled to one side (e.g., a lower side in the drawing) of the stator <NUM>.

The bracket <NUM> includes, for example, a bearing accommodating portion <NUM> in which the bearing <NUM> is accommodated and a plurality of leg portions <NUM> having one end connected to the bearing accommodating portion <NUM> and the other end bent to be disposed in the axial direction.

In some implementations, the second bearing 310b is accommodated and coupled to the bearing accommodating portion <NUM> of the bracket <NUM>.

The plurality of leg portions <NUM> is implemented, for example, in three pieces.

The plurality of leg portions <NUM> include, for example, a radial section <NUM> extending along a radial direction from the bearing accommodating portion <NUM> and an axial section <NUM> bent from the radial section <NUM> and extending in the axial direction.

In an outer boundary region of the radial section <NUM> and the axial section <NUM>, an inclined portion <NUM> cut obliquely with respect to the axial direction is provided.

A fastening member insertion portion <NUM> is disposed through the axial section <NUM> so that the fastening member <NUM> coupled to the second diffuser <NUM> may be inserted. Here, the fastening member <NUM> may be configured to be screwed to the second diffuser <NUM>.

The stator coil <NUM> can be connected to a printed circuit board (PCB) <NUM>.

The stator coil <NUM> may be connected to, for example, a three-phase AC power source.

The stator coil <NUM> may include a plurality of phase coils connected to phase power (U-phase, V-phase, and W-phase) of the AC power.

In some implementations, the motor assembly <NUM> may be implemented, for example, as a relatively small motor assembly in which an outer diameter of the impeller cover <NUM> is about <NUM>, an outer diameter of the stator <NUM> is about <NUM>, and an outer diameter of the rotor <NUM> is about <NUM>. Therefore, the size and weight of the motor assembly <NUM> may be reduced. Further, in some implementations, when the motor assembly <NUM> is installed in a handheld device, installation and handling may be facilitated.

In some implementations, the stator <NUM> and the rotor <NUM> are implemented so that high-speed rotation (e.g., <NUM> krpm to <NUM> krpm) is possible.

As a result, even though the size and weight of the motor assembly <NUM> are reduced, a relatively high-speed rotation is secured, so that an air volume can be maintained or secured to the level that is equal to or greater than that of a motor assembly having no reduction in size and weight.

A plurality of connection terminals <NUM> respectively connected to the plurality of phase coils are provided on one side of the stator <NUM>. The stator <NUM> includes a plurality of connection terminal support portions <NUM> supporting the plurality of connection terminals <NUM>. The connection terminal support portion <NUM> may be provided in the insulator <NUM>, for example. The plurality of connection terminal support portions <NUM> are spaced apart from each other in the circumferential direction. The plurality of connection terminal support portions <NUM> are configured to extend to one side (e.g., a lower side in the drawing) along the axial direction. The plurality of connection terminal support portions <NUM> are provided such that the plurality of connection terminals <NUM> are respectively arranged on the downstream side of the bracket <NUM> in the axial direction. The plurality of connection terminals <NUM> may be respectively arranged between the plurality of leg portions <NUM> of the bracket <NUM>, for example.

The PCB <NUM> is provided on one side (e.g., a lower side in the drawing) of the bracket <NUM> in the axial direction.

The PCB <NUM> includes, for example, a substrate <NUM> and a circuit component <NUM> mounted on the substrate <NUM>. The substrate <NUM> may include, for example, an inverter circuit capable of providing three-phase AC power to the stator coil <NUM>.

The substrate <NUM> may be implemented, for example, in a disk shape.

A plurality of connection terminal insertion portions <NUM> to which the plurality of connection terminals <NUM> are respectively inserted and coupled are provided on the substrate <NUM>. The plurality of connection terminal insertion portions <NUM> are respectively disposed to penetrate through the substrate <NUM>.

The plurality of connection terminal insertion portions <NUM> include a joint portion <NUM> for electrically connecting the plurality of connection terminals <NUM>, respectively. The joint portion <NUM> may be provided, for example, by soldering the connection terminal <NUM> and the connection terminal insertion portion <NUM> to each other.

<FIG> is a perspective view of the first diffuser of <FIG>. As shown in <FIG>, the first diffuser <NUM> includes the hub <NUM> and the plurality of blades <NUM>.

The first diffuser <NUM> is formed of, for example, a synthetic resin member. Accordingly, a weight of the first diffuser <NUM> may be reduced.

The hub <NUM> of the first diffuser <NUM> has a downwardly opened cylindrical shape.

For example, the hub <NUM> of the first diffuser <NUM> may have an upstream end blocked and a downstream end open based on a moving direction of the air moved by the impeller <NUM>.

The hub <NUM> of the first diffuser <NUM> includes a cylindrical portion <NUM> and a disk portion <NUM> disposed to block one end of the cylindrical portion <NUM> along the axial direction.

In some implementations, the disk portion <NUM> of the first diffuser <NUM> is disposed at an upstream end of the cylindrical portion <NUM>.

A through portion <NUM> is disposed in the center of the hub <NUM> (e.g., the disk portion <NUM>) of the first diffuser <NUM> so that a protrusion <NUM> of the second diffuser <NUM>, which will be described later, may be inserted.

The first diffuser <NUM> may be fastened to the second diffuser <NUM> by a fastening member <NUM>.

Accordingly, the coupling force between the first diffuser <NUM> and the second diffuser <NUM> may be improved.

A fastening member insertion hole <NUM> is disposed through the hub <NUM> of the first diffuser <NUM> so that the fastening member <NUM> may be inserted.

The fastening member insertion hole <NUM> is provided as a plurality of fastening member insertion holes spaced apart from each other in the circumferential direction on the circumference of the through portion <NUM>.

A plurality of blades <NUM> are provided on the outer surface of the hub <NUM> of the first diffuser <NUM>. The plurality of blades <NUM> are arranged to be spaced apart from each other in the circumferential direction. The plurality of blades <NUM> are, for example, respectively arranged to be inclined with respect to the axial direction. For example, the plurality of blades <NUM> are each implemented in a curved cross-sectional shape in which the center is convex toward the upstream side.

The plurality of blades <NUM> are each configured such that a downstream end is disposed in front of an upstream end based on a rotation direction of the impeller <NUM>.

The plurality of blades <NUM> of the first diffuser <NUM> is configured such that an upstream end <NUM> and a downstream end <NUM> of two adjacent blades <NUM> overlap each other in the axial direction.

The downstream end <NUM> of the rear blade <NUM> based on the rotation direction of the impeller <NUM> is disposed at a lower front than the upstream end <NUM> of the front blade <NUM>. That is, the two blades adjacent to each other of the first diffuser <NUM> are disposed to overlap each other in the axial direction by about half the length of the blades.

<FIG> is a side view of the second diffuser of <FIG>, <FIG> is a cross-sectional view of the second diffuser of <FIG>, <FIG> is a bottom view of the second diffuser of <FIG>, <FIG> is a bottom perspective view of the second diffuser of <FIG>, and <FIG> is a view in which an outer wall of the second diffuser of <FIG> is removed. As shown in <FIG>, the second diffuser <NUM> includes a hub <NUM>, an outer wall <NUM>, and a plurality of blades <NUM>.

The hub <NUM> of the second diffuser <NUM> has a cylindrical shape with one side (e.g., a lower side in the drawing) opened. The hub <NUM> of the second diffuser <NUM> is implemented in a downwardly opened cylindrical shape. The hub <NUM> of the second diffuser <NUM> includes, for example, a cylindrical portion <NUM> and a disk portion <NUM> disposed to block one end of the cylindrical portion <NUM> along the axial direction.

The hub <NUM> of the second diffuser <NUM> is configured to be inserted into the hub <NUM> of the first diffuser <NUM>.

The outer surface of the hub <NUM> of the second diffuser <NUM> is configured to be in surface contact with the inner surface of the hub <NUM> of the first diffuser <NUM>.

For example, the cylindrical portion <NUM> of the hub <NUM> of the second diffuser <NUM> is coupled to be in surface contact with the inner surface of the cylindrical portion <NUM> of the hub <NUM> of the first diffuser <NUM>.

The disk portion <NUM> of the hub <NUM> of the second diffuser <NUM> is coupled to be in surface contact with the inner surface of the cylindrical portion <NUM> of the hub <NUM> of the first diffuser <NUM>.

The hub <NUM> of the second diffuser <NUM> is configured to protrude toward one side (e.g., a lower side in the drawing) along the axial direction when coupled with the first diffuser <NUM>.

In some implementations, any one of the mutual contact surfaces (e.g., interfacing surfaces) of the second diffuser <NUM> and the first diffuser <NUM> includes an axially protruding anti-rotation protrusion <NUM>, and the other includes an anti-rotation protrusion accommodating recess <NUM> into which the anti-rotation protrusion is inserted.

The anti-rotation protrusion <NUM> may be disposed, for example, on the second diffuser <NUM>. The anti-rotation protrusion <NUM> is provided on the radially outer side of the protrusion <NUM>. For example, the anti-rotation protrusion <NUM> is disposed to protrude from the outer surface of the second diffuser <NUM>.

The anti-rotation protrusion accommodating recess <NUM> may be disposed in the first diffuser <NUM>. The anti-rotation protrusion accommodating recess <NUM> is, for example, disposed to be recessed along the axial direction on the inner surface of the first diffuser <NUM>. The anti-rotation protrusion accommodating recess <NUM> is provided on the radially outer side of the through portion <NUM>.

The hub <NUM> of the second diffuser <NUM> includes a first section <NUM> inserted into the hub <NUM> of the first diffuser <NUM> and a second section <NUM> disposed outside the first diffuser <NUM>. Here, the second section <NUM> is configured to further protrude outward from an outer circumference of the first section <NUM> in the radial direction.

An outer diameter of the second section <NUM> is larger than an outer diameter of the first section <NUM>.

The outer diameter of the second section <NUM> may be, for example, the same size as the outer diameter of the hub <NUM> of the first diffuser <NUM>.

When the first diffuser <NUM> and the second diffuser <NUM> are combined, a lower end of the first diffuser <NUM> may be in surface contact with an upper end of the second section <NUM>.

A bearing accommodating portion <NUM> is provided at the center of the hub <NUM> of the second diffuser <NUM>.

The bearing accommodating portion <NUM> of the second diffuser <NUM> is disposed on a rear surface of the protrusion <NUM>.

The bearing accommodating portion <NUM> of the second diffuser <NUM> is disposed to protrude along the axial direction at an inner center of the hub <NUM> of the second diffuser <NUM>.

The bearing accommodating portion <NUM> is disposed in the disk portion <NUM> of the hub <NUM> of the second diffuser <NUM>.

An accommodating space <NUM> in which the bearing <NUM> (e.g., the first bearing 310a) is accommodated is disposed in the bearing accommodating portion <NUM>.

The second diffuser <NUM> is formed of a member having superior thermal conductivity compared to the first diffuser <NUM>. Therefore, cooling of the bearing <NUM> (e.g., the first bearing 310a) accommodated in the bearing accommodating portion <NUM> may be promoted.

The second diffuser <NUM> is formed of a metal member. Accordingly, heat dissipation of the second diffuser <NUM> may be promoted. In addition, the rigidity of the second diffuser <NUM> may be improved. The second diffuser <NUM> is formed of, for example, an aluminum (Al) member.

A through hole <NUM> through which the rotating shaft <NUM> may pass is provided in the protrusion <NUM>. The protrusion <NUM> is inserted and coupled to the through portion <NUM> of the first diffuser <NUM> along the axial direction. Accordingly, the first diffuser <NUM> and the second diffuser <NUM> overlap each other along the axial direction, so that an axial length may be shortened. In addition, the occurrence of lateral gap between the first diffuser <NUM> and the second diffuser <NUM> may be restricted.

The second diffuser <NUM> includes a stator coupling portion <NUM> coupled to the stator <NUM>. The stator coupling portion <NUM> is provided inside the second diffuser <NUM>.

The stator coupling portion <NUM> is provided as a plurality of stator coupling portions spaced apart from each other in the circumferential direction of the second diffuser <NUM>. In some implementations, the stator coupling portion <NUM> is implemented as three stator coupling portions.

The stator coupling portion <NUM> is disposed to protrude from, for example, an inner surface of the hub <NUM> of the second diffuser <NUM>.

The stator coupling portion <NUM> has a radial section <NUM> having one end connected to the outer surface of the bearing accommodating portion <NUM> and the other end extending in the radial direction.

The stator coupling portion <NUM> has an axial section <NUM> extending along the axial direction from the radial section <NUM>. The axial section <NUM> is configured to protrude from the inner circumferential surface of the hub <NUM> of the second diffuser <NUM> in the radial direction and to be disposed along the axial direction.

The radial section <NUM> protrudes along the axial direction from the inner surface of the second diffuser <NUM>. The radial section <NUM> has, for example, the same height Hr as that of the bearing accommodating portion <NUM>.

The stator coupling portion <NUM> includes an outer circumferential surface contact portion <NUM> that is in surface contact with the outer circumferential surface of the stator <NUM> (e.g., the stator core <NUM>).

Each of the outer circumferential surface contact portions <NUM> is configured to have, for example, a radius of curvature corresponding to the outer diameter of the stator core <NUM>.

Accordingly, the second diffuser <NUM> and the stator <NUM> (e.g., the stator core <NUM>) may be concentrically coupled to each other.

The bearing accommodating portion <NUM> of the second diffuser <NUM> is implemented in a downwardly opened cylindrical shape.

The bearing accommodating portion <NUM> of the second diffuser <NUM> includes the through hole <NUM> through which the rotating shaft <NUM> may pass.

The second diffuser <NUM> includes a fastening member coupling portion <NUM> to communicate with the fastening member insertion hole <NUM> provided in the first diffuser <NUM>. The fastening member coupling portion <NUM> provided in the hub <NUM> of the second diffuser <NUM> may be configured such that, for example, the fastening member <NUM> passing through the fastening member insertion hole <NUM> of the first diffuser <NUM> is screwed thereto.

The fastening member coupling portion <NUM> of the second diffuser <NUM> may be disposed, for example, through each of the radial sections <NUM> of the stator coupling portion <NUM>.

The stator coupling portion <NUM> includes an end surface contact portion <NUM> in surface contact with one end (e.g., an upper end in the drawing) of the stator <NUM> along the axial direction. Accordingly, the occurrence of an axial gap between the second diffuser <NUM> and the stator <NUM> may be restricted.

The end surface contact portion <NUM> is provided in the axial section <NUM> of the stator coupling portion <NUM>.

According to this configuration, the stator <NUM> and the bearing <NUM> (e.g., the first bearing 310a) may be spaced apart from each other by a preset distance along the axial direction.

Accordingly, an increase in the temperature of the bearing <NUM> provided in the second diffuser <NUM> due to thermal energy generated by the stator <NUM> may be restricted.

The end surface contact portion <NUM> is disposed to be spaced apart from the lower end of the cylindrical portion <NUM> of the hub <NUM> of the second diffuser <NUM> in the axial direction.

The end surface contact portion <NUM> is disposed to be spaced apart from the disk portion <NUM> of the hub <NUM> along the axial direction.

As shown in <FIG>, the axial section <NUM> is configured to protrude from the hub <NUM> of the second diffuser <NUM> in the axial direction.

For example, the stator coupling portion <NUM> is configured to protrude downward from the lower end (e.g., a downstream end of the hub <NUM>) of the hub <NUM> of the second diffuser <NUM>.

The stator coupling portion <NUM> (e.g., the axial section <NUM>) includes a fastening member coupling portion <NUM> so that the fastening member <NUM> coupled in the bracket <NUM> may be screwed therethrough.

The fastening member coupling portion <NUM> of the stator coupling portion <NUM> is disposed at a preset depth along the axial direction from the downstream end of the axial section <NUM>.

The plurality of blades <NUM> of the second diffuser <NUM> are shorter than the plurality of blades <NUM> of the first diffuser <NUM>.

As shown in <FIG>, the plurality of blades <NUM> of the second diffuser <NUM> are configured such that two blades adjacent to each other in the circumferential direction are spaced apart from each other at preset intervals along the circumferential direction.

For example, among the two blades <NUM> adjacent to each other, the downstream end of the blade disposed at the rear is disposed to be spaced apart rearward compared to the upstream end of the blade <NUM> disposed at the front with respect to the rotation direction of the impeller <NUM>.

According to this configuration, the manufacturing of the second diffuser <NUM> may be facilitated.

Referring to <FIG> and <FIG> together, the hub <NUM> of the second diffuser <NUM> includes a communicating portion <NUM> allowing the inside and the outside to communicate with each other. Accordingly, the air inside the second diffuser <NUM> may be discharged to the outside of the second diffuser <NUM>.

According to this configuration, the air inside the second diffuser <NUM>, having a temperature increased by thermal energy generated during operation of the motor <NUM> (e.g., the stator <NUM> and the rotor <NUM>), is discharged to the outside of the second diffuser <NUM> through the communicating portion <NUM>, thereby reducing an internal temperature of the second diffuser <NUM>.

Because the temperature rise of the stator <NUM> and the rotor <NUM> is restricted, it may be restricted that power of the motor <NUM> is inhibited due to an increase in electrical resistance of the stator <NUM> and the rotor <NUM> when the temperature of the stator <NUM> and the rotor <NUM> increases. It is further restricted that the output of the motor <NUM> is inhibited due to an increase in electrical resistance of the stator <NUM> and the rotor <NUM> when the temperature of the stator <NUM> and the rotor <NUM> increases. That is, because the stator <NUM> and the rotor <NUM> in some implementations are operated at a relatively low temperature by the air discharge action of the communicating portion <NUM>, the power of the motor <NUM> may be increased.

The communicating portion <NUM> may be implemented as a plurality of communication portions spaced apart along the circumferential direction of the second diffuser <NUM>. The communicating portion <NUM> may be implemented, for example, as two to fifteen communicating portions. In some implementations, nine communicating portions <NUM> are implemented as illustrated. However, this is only a non-limiting example.

The communicating portion <NUM> is disposed on the upstream side of each of the plurality of blades <NUM> of the second diffuser <NUM>.

<FIG> is an enlarged view of a communicating portion region of <FIG>, <FIG> is a cross-sectional view of the communicating portion region of the second diffuser of <FIG>, <FIG> is a cross-sectional view of a communicating portion region of a second diffuser of a motor assembly according to an implementation of the present disclosure, and <FIG> is a cross-sectional view of a communicating portion region of a second diffuser of a motor assembly according to an implementation of the present disclosure.

As shown in <FIG> and <FIG>, the communicating portion <NUM> is disposed to penetrate through the cylindrical portion <NUM> of the hub <NUM> of the second diffuser <NUM> in the radial direction.

The communicating portion <NUM> may be implemented, for example, in the shape of a long hole having a length longer than a width.

The communicating portion <NUM> has a length disposed in the circumferential direction of the cylindrical portion <NUM> of the hub <NUM> of the second diffuser <NUM> and has a width disposed in the axial direction of the cylindrical portion <NUM> of the hub <NUM>.

The communicating portion <NUM> is disposed on one side (e.g., a lower side in the drawing) of the first diffuser <NUM> in the axial direction.

The communicating portion <NUM> is disposed on one side (e.g., a lower side) of the plurality of blades <NUM> of the first diffuser <NUM> in the axial direction.

Referring back to <FIG>, the communicating portion <NUM> is disposed in the second section <NUM> of the cylindrical portion <NUM> of the second diffuser <NUM>.

Each of the communicating portions <NUM> is disposed so that the upstream side (e.g., an upper side) is opened along the axial direction.

The open region on the upstream side of the communicating portion <NUM> is blocked by the downstream end (e.g., a lower end) of the first diffuser <NUM> when the first diffuser <NUM> and the second diffuser <NUM> are coupled.

In some implementations, as described above, the number of communicating portions <NUM> may be nine. For example, three of the communicating portions <NUM> may be separately disposed through, for example, the stator coupling portion <NUM> (e.g., the axial section <NUM>). Six of the communicating portions <NUM> may be disposed to penetrate through the cylindrical portion (e.g., the second section <NUM>) of the hub <NUM> of the second diffuser <NUM>.

As shown in <FIG>, the second diffuser <NUM> may be configured to include six communicating portions 205a. In some implementations, three of the six communicating portions 205a may be disposed to radially penetrate through the stator coupling portion <NUM> (e.g., the axial section <NUM>). Three of the six communicating portions <NUM> may be disposed to radially penetrate through the hub <NUM> (e.g., the second section <NUM>) of the second diffuser <NUM> to be respectively disposed between the stator coupling portions <NUM>.

Also, as shown in <FIG>, the second diffuser <NUM> may include twelve communicating portions 205b. Three of the twelve communicating portions 205b may be disposed through the stator coupling portion <NUM>. Nine of the twelve communicating portions 205b may be configured to be arranged by three each between the stator coupling portions <NUM>.

According to this configuration, when the impeller cover <NUM>, the impeller <NUM>, the first diffuser <NUM>, the second diffuser <NUM>, and the motor <NUM> are intended to be coupled, the second diffuser <NUM> is inserted and coupled to the inside of the first diffuser <NUM> and the bearing <NUM> (e.g., the first bearing 310a) is accommodated and coupled to the bearing accommodating portion <NUM> of the second diffuser <NUM>.

The stator <NUM> may be inserted and coupled to the second diffuser <NUM> along the axial direction, and the rotor <NUM> may be inserted and coupled to the inside of the stator <NUM>.

The upper end of the rotating shaft <NUM> of the rotor <NUM> is coupled to pass through the first bearing 310a, and the impeller <NUM> is coupled to the upper end of the rotating shaft <NUM>.

The bearing <NUM> (e.g., the second bearing 310b) is coupled to a lower region of the rotating shaft <NUM> of the rotor <NUM>, and the second bearing 310b is inserted and coupled to the bearing accommodating portion <NUM> of the bracket <NUM>.

The plurality of leg portions <NUM> of the bracket <NUM> are respectively fixedly coupled to the stator coupling portion <NUM> by the fastening member <NUM>.

The connection terminal support portions <NUM> of the stator <NUM> are respectively disposed between the plurality of leg portions <NUM> of the bracket <NUM>, and the PCB <NUM> is electrically coupled to the connection terminal <NUM> protruding downward of the bracket <NUM> along the axial direction. Accordingly, a three-phase AC power may be applied to the stator coil <NUM>.

When the operation is started and power is applied to the stator coil <NUM>, the stator coil <NUM> generates a magnetic force, and the rotor <NUM> rotates about the rotating shaft <NUM> by the interaction of the magnetic force of the permanent magnet <NUM> and the magnetic force of the stator coil <NUM>.

When the impeller <NUM> is rotated by the rotation of the rotor <NUM>, air is sucked into the impeller cover <NUM> through the suction port <NUM>.

The air sucked into the impeller cover <NUM> is guided by the plurality of blades <NUM> of the first diffuser <NUM> and the plurality of blades <NUM> of the second diffuser <NUM> along the axial direction and discharged to the downstream side of the second diffuser <NUM>. The discharged air moves downward along the axial direction from the radially outer side of the stator <NUM>.

When the operation is started and the impeller <NUM> is rotated, the speed of the air on the downstream side of the impeller <NUM> increases and the pressure decreases. At this time, because an external air flow path Pa of the second diffuser <NUM> along the radial direction is in a relatively low pressure state, the air inside the hub <NUM> of the second diffuser <NUM> flows to the outside of the hub <NUM> of the second diffuser <NUM> through the communicating portion <NUM>.

When the impeller <NUM> rotates, the air inside the hub <NUM> of the second diffuser <NUM> continuously flows out through the communicating portion <NUM>, so that air is continuously moved toward the communicating portion <NUM> via an upper region of the motor <NUM> (e.g., the stator <NUM> and the rotor <NUM>). Accordingly, the motor <NUM> (e.g., the stator <NUM> and the rotor <NUM>) may be continuously cooled by the air continuously moving toward the communicating portion <NUM>. As a result, the stator <NUM> and the rotor <NUM> may maintain a relatively low temperature, and an increase in electrical resistance due to a temperature rise may be restricted, thereby increasing the power of the motor <NUM>.

<FIG> is a bottom perspective view of a second diffuser of the motor assembly according to an implementation of the present disclosure, and <FIG> are modified examples of a heat dissipation fin of <FIG>.

As shown in <FIG>, a second diffuser 190a of the motor assembly according to an implementation of the present disclosure includes a hub <NUM>, an outer wall <NUM> concentrically disposed on the outside of the hub <NUM>, and a plurality of blades <NUM> having one end connected to the hub <NUM> and the other end connected to the outer wall <NUM> as described above.

The hub <NUM> of the second diffuser 190a includes a bearing accommodating portion <NUM> in which the bearing <NUM> is accommodated.

The second diffuser 190a includes a stator coupling portion <NUM> coupled to the stator <NUM>.

The stator coupling portion <NUM> includes a radial section <NUM> having one end connected to the bearing accommodating portion <NUM> and extending in the radial direction and an axial section <NUM> extending from the radial section <NUM> in the axial direction.

The stator coupling portion <NUM> includes an outer circumferential surface contact portion <NUM> in surface contact with the outer circumference of the stator <NUM> and an end surface contact portion <NUM> in surface contact with one end of the stator <NUM> along the axial direction.

The second diffuser 190a includes a communicating portion <NUM> allowing the inside and the outside of the hub <NUM> of the second diffuser 190a to communicate with each other.

The second diffuser 190a is formed of a metal member. For example, the second diffuser 190a is formed of an aluminum (Al) member.

In some implementations, the second diffuser 190a includes the protruding heat dissipation fin <NUM> to increase a surface area.

The heat dissipation fin <NUM> includes, for example, a radial heat dissipation fin <NUM> having one end connected to the circumference of the bearing accommodating portion <NUM> and the other end extending in the radial direction.

Therefore, heat dissipation of the bearing accommodating portion <NUM> may be promoted. In addition, the bearing strength of the bearing accommodating portion <NUM> may be improved.

According to this configuration, the occurrence of vibration of the bearing <NUM> (e.g., the first bearing 310a) provided in the bearing accommodating portion <NUM> may be restricted. In addition, cooling of the bearing <NUM> (e.g., the first bearing 310a) provided in the bearing accommodating portion <NUM> may be promoted.

The radial heat dissipation fin <NUM> may be respectively disposed between the stator coupling portions <NUM> along the circumferential direction, for example.

In some implementations, the radial heat dissipation fin <NUM> may be implemented in three pieces.

The radial heat dissipation fin <NUM> has the same height as that of the stator coupling portion <NUM> along the axial direction.

In some implementations, the heat dissipation fin <NUM> includes a circumferential heat dissipation fin <NUM> disposed along the circumferential direction on the circumference of the bearing accommodating portion <NUM>.

Accordingly, heat dissipation of the second diffuser 190a may be promoted. In addition, the rigidity of the second diffuser 190a may be improved.

According to this configuration, the occurrence of vibration of the bearing <NUM> (e.g., the first bearing 310a) provided in the bearing accommodating portion <NUM> may be restricted. In addition, cooling of the bearing <NUM> (e.g., first bearing 310a) provided in the bearing accommodating portion <NUM> may be promoted.

The circumferential heat dissipation fin <NUM> are implemented as a plurality of circumferential heat dissipation fins concentrically arranged around the bearing accommodating portion <NUM>.

The circumferential heat dissipation fin <NUM> may be disposed to correspond to the number of the radial heat dissipation fin <NUM>. In some implementations, the circumferential direction heat dissipation fin <NUM> is implemented as three fins.

For example, a protrusion height Hc protruding from the inner surface of the hub <NUM> of the circumferential heat dissipation fin <NUM> in the axial direction is smaller than a protrusion height Hr protruding from the inner surface of the hub <NUM> of the radial heat dissipation fin <NUM> in the axial direction.

The radial heat dissipation fin <NUM> is configured to protrude further from the inner surface of the hub <NUM> in the axial direction than the circumferential heat dissipation fin <NUM>.

Here, as shown in <FIG>, the heat dissipation fin 220a in some implementations may include a radial heat dissipation fin <NUM> and a circumferential heat dissipation fin <NUM> having the same protrusion height from the inner surface of the hub <NUM> along the axial direction.

In some implementations, the radial heat dissipation fin <NUM> and the circumferential heat dissipation fin <NUM> may be configured to have, for example, the same height as that of the stator coupling portion <NUM>.

In addition, as shown in <FIG>, a heat dissipation fin 220b in some implementations includes a radial heat dissipation fin 221b and a circumferential heat dissipation fin 222b respectively protruding from the inner surface of the hub <NUM> along the axial direction. In some implementations, a protrusion height Hr of the radial heat dissipation fin 221b protruding from the disk portion <NUM> of the hub <NUM> along the axial direction is equal to a protrusion height Hc of the circumferential heat dissipation fin 222b. The protrusion height Hr of the radial heat dissipation fin 221b and the protrusion height Hc of the circumferential heat dissipation fin 222b have protrusion heights Hr and Hc smaller than the protrusion height Hs of the stator coupling portion <NUM> protruding from the disk portion <NUM> of the hub <NUM> along the axial direction.

The heat dissipation fin <NUM> may include radial heat dissipation fin <NUM> and circumferential heat dissipation fin <NUM> disposed in different numbers.

As shown in <FIG>, the heat dissipation fin 220c includes three circumferential heat dissipation fins 222c and six radial heat dissipation fins 221c embodied therein. In some implementations, the radial heat dissipation fin 221c may be configured by two between the stator coupling portions <NUM> adjacent to each other in the circumferential direction. The circumferential heat dissipation fins 222c may be respectively disposed between the radial heat dissipation fins 221c in the circumferential direction.

The circumferential heat dissipation fin 222c is configured to connect the stator coupling portion <NUM> and the radial heat dissipation fin 221c adjacent to each other along the circumferential direction, or connect two circumferential heat dissipation fins 222c adjacent to each other.

As shown in <FIG>, a heat dissipation fin 220d includes three radial heat dissipation fins 222d and nine radial heat dissipation fins 221d. In some implementations, the radial heat dissipation fins 221d may be configured by three between the two stator coupling portions <NUM> adjacent to each other in the circumferential direction. Each of the circumferential heat dissipation fins 222d may be provided between two radial heat dissipation fins 221d adjacent to each other, respectively.

Each of the circumferential heat dissipation fins 222d is configured to connect the stator coupling portion <NUM> and the radial heat dissipation fin 221d adjacent to each other, or connect two circumferential heat dissipation fins 222d adjacent to each other, respectively.

As shown in <FIG>, a heat dissipation fin 220e includes two circumferential heat dissipation fins 222d spaced apart from each other in the radial direction around the bearing accommodating portion <NUM> and three radial heat dissipation fins 221d respectively arranged between two stator coupling portions <NUM> adjacent to each other.

Each of the circumferential heat dissipation fins 222d is configured such that one end is connected to the stator coupling portion <NUM> and the other end is connected to the radial heat dissipation fin 221d.

<FIG> is a cross-sectional view of a motor assembly according to an implementation of the present disclosure, and <FIG> is an enlarged view of a main part of <FIG>. A motor assembly 100a in some implementations includes an impeller <NUM>, an impeller cover <NUM>, a first diffuser <NUM>, a second diffuser 190b, and a motor <NUM>.

The impeller cover <NUM>, the impeller <NUM>, the first diffuser <NUM>, the second diffuser 190b, and the motor <NUM> are coupled to each other along the axial direction.

The impeller <NUM> is accommodated inside the impeller cover <NUM>, and the first diffuser <NUM> is coupled to a downstream side of the impeller <NUM>. The second diffuser 190b is coupled to the first diffuser <NUM>, and the impeller cover <NUM> is coupled to the second diffuser 190b so that the impeller <NUM> and the first diffuser <NUM> are accommodated therein.

Here, an air flow path Pa through which the air introduced by the rotation of the impeller <NUM> moves is disposed between the impeller cover <NUM>, the first diffuser <NUM>, and the second diffuser 190b.

The motor <NUM> is coupled to the second diffuser 190b.

The motor <NUM> has a stator <NUM> and a rotor <NUM> that is rotatably accommodated with a predetermined air gap G with respect to the stator <NUM>.

The stator <NUM> includes a stator core <NUM> and a stator coil <NUM> wound around the stator core <NUM>. The stator <NUM> includes a plurality of connection terminals <NUM> having one end electrically connected to the stator coil <NUM> and the other end extending along the axial direction.

The plurality of connection terminals <NUM> are electrically connected to the PCB <NUM>. The PCB <NUM> includes a substrate <NUM> and a plurality of circuit components <NUM> provided on the substrate <NUM>. The PCB <NUM> may include, for example, an inverter circuit to provide three-phase AC power to the stator coil <NUM>.

The rotor <NUM> includes a rotating shaft <NUM> and a permanent magnet <NUM> rotating about the rotating shaft <NUM>. The rotating shaft <NUM> is rotatably supported by a bearing <NUM>. The bearing <NUM> includes a first bearing 310a and a second bearing 310b respectively provided on both sides (e.g., upper and lower sides in the drawing) of the permanent magnet <NUM> along the axial direction. The first bearing 310a may have a larger size than that of the second bearing 310b.

The impeller <NUM> includes a hub <NUM> and a plurality of blades <NUM> provided around the hub <NUM>.

The first diffuser <NUM> includes a cylindrical hub <NUM> and a plurality of blades <NUM> provided on an outer surface of the hub <NUM>.

Outer ends of the plurality of blades <NUM> of the first diffuser <NUM> along the radial direction are disposed to face an inner circumferential surface of the impeller cover <NUM>. For example, the outer ends of the plurality of blades <NUM> of the first diffuser <NUM> along the radial direction are configured to contact the inner circumferential surface of the impeller cover <NUM>.

The second diffuser 190b includes a cylindrical hub <NUM>, an outer wall <NUM> concentrically disposed on the outside of the hub <NUM>, and a plurality of blades <NUM> having one end connected to the hub <NUM> and the other end connected to the outer wall <NUM>.

The hub <NUM> of the second diffuser 190b is configured to be inserted into the hub <NUM> of the first diffuser <NUM>.

One of the mutual contact surfaces (e.g., interfacing surfaces) of the first diffuser <NUM> and the second diffuser 190b includes an axially protruding anti-rotation protrusion <NUM>, and the other includes the anti-rotation protrusion accommodating recess <NUM> into which the anti-rotation protrusion <NUM> is inserted.

The anti-rotation protrusion <NUM> is disposed to protrude from the outer surface of the second diffuser <NUM> in the axial direction, and the anti-rotation protrusion accommodating recess <NUM> is recessed on the inner surface of the first diffuser <NUM> along the axial direction.

The hub <NUM> of the second diffuser 190b includes a cylindrical portion <NUM> and a disk portion <NUM> disposed to block one end of the cylindrical portion <NUM> along the axial direction.

The cylindrical portion <NUM> of the hub <NUM> of the second diffuser 190b includes a first section <NUM> inserted into the first diffuser <NUM> and a second section <NUM> protruding to the outside of the first diffuser <NUM>.

The hub <NUM> (e.g., the disk portion <NUM>) of the second diffuser 190b includes a bearing accommodating portion <NUM> in which the bearing <NUM> (e.g., the first bearing 310a) is accommodated.

A stator coupling portion <NUM> to which the stator <NUM> is coupled is disposed in the second diffuser 190b. The stator coupling portion <NUM> includes a radial section <NUM> having one end connected to the bearing accommodating portion <NUM> and the other end extending in the radial direction and an axial section <NUM> extending from the end of the radial section <NUM> along the axial direction.

A bracket <NUM> accommodating and supporting the bearing <NUM> (e.g., the second bearing 310b) is provided on one side (e.g., a lower side in the drawing) of the motor <NUM> along the axial direction.

The bracket <NUM> includes a bearing accommodating portion <NUM> accommodating the bearing <NUM> (e.g., the second bearing 310b) and a plurality of leg portions <NUM> having one end connected to the bearing accommodating portion <NUM> and the other end bent to be disposed along the axial direction. The plurality of leg portions <NUM> are respectively coupled to the stator coupling portion <NUM> of the second diffuser 190b.

In some implementations, the hub <NUM> of the second diffuser 190b includes a communicating portion 205c allowing the inside and the outside of the hub <NUM> to communicate with each other.

The communicating portion 205c includes a radial section <NUM> disposed to extend outwardly of the cylindrical portion <NUM> along the radial direction at the disk portion <NUM> of the hub <NUM> of the second diffuser 190b and an axial section <NUM> having one side extending from the radial section <NUM> and the other side extending along the axial direction.

In some implementations, the radial section <NUM> of the communicating portion 205c has an inlet <NUM> communicating with the inside of the disk portion <NUM> of the hub of the second diffuser 190b.

The radial section <NUM> of the communicating portion 205c has an external opening <NUM> communicating with the outside of the hub <NUM>.

Therefore, the air inside the hub <NUM> of the second diffuser 190b is moved to the outside of the hub <NUM> through the inlet <NUM>, the radial section <NUM>, and the external opening <NUM>.

In some implementations, the communicating portion 205c may be implemented as a plurality of communicating portions spaced apart from each other in the circumferential direction of the second diffuser 190b. The communicating portion 205c may be disposed, for example, as two to fifteen communicating portions.

In some implementations, some (for example, three) of the plurality of communicating portions 205c may be disposed in the stator coupling portion <NUM>.

The axial section <NUM> includes a first axial section <NUM> recessed in the outer surface of the cylindrical portion <NUM> of the hub <NUM> of the second diffuser 190b.

The first axial section <NUM> has an outlet <NUM> through which air is discharged. The outlet <NUM> is disposed to open outwardly between the plurality of blades <NUM> of the first diffuser <NUM> and the plurality of blades <NUM> of the second diffuser 190b.

Accordingly, the air moved to the outside of the hub <NUM> of the second diffuser 190b through the inlet <NUM> and the radial section <NUM> is moved along the first axial section <NUM> and may flow out to the air flow path Pa through the outlet <NUM>.

The axial section <NUM> includes a second axial section <NUM> recessed in the inner surface of the hub <NUM> of the first diffuser <NUM>. The second axial section <NUM> forms a flow path through which air moves cooperatively with the first axial section <NUM>.

In some implementations, the axial section <NUM> includes both the first axial section <NUM> and the second axial section <NUM>, so that an increase in the thickness of each of the hub <NUM> of the first diffuser <NUM> and the hub <NUM> of the second diffuser 190b may be restricted.

The upstream end of the second axial section <NUM> is disposed to correspond to the external opening <NUM> of the radial section <NUM>, and the downstream end extends to the downstream end of the first diffuser <NUM>.

According to this configuration, when the operation is started and power is applied to the stator coil <NUM>, the rotor <NUM> rotates about the rotating shaft <NUM> according to interaction between the magnetic force generated by the stator coil <NUM> and the magnetic force of the permanent magnet <NUM>.

When the rotating shaft <NUM> is rotated, the impeller <NUM> is rotated, and air is sucked into the impeller cover <NUM> through the suction port <NUM>. The sucked air moves to the downstream side along the outside of the motor <NUM> via the impeller <NUM>, the first diffuser <NUM>, and the second diffuser 190b.

When the impeller <NUM> is rotated, the pressure on the downstream side of the impeller <NUM> is relatively lowered, and the air heated by the motor <NUM> present between the second diffuser 190b and the motor <NUM> moves along the inlet <NUM>, the radial section <NUM>, and the axial section <NUM> and then flows out to the air flow path Pa through the outlet <NUM>.

Accordingly, a relatively low temperature air around the motor <NUM> is introduced between the hub <NUM> of the second diffuser 190b and the motor <NUM>, and in this process, the relatively low temperature air and the motor <NUM> comes into contact with each other, thereby cooling the motor <NUM>.

According to this configuration, when the impeller <NUM> rotates, the air between the second diffuser 190b and the motor <NUM> continuously flows out of the hub <NUM> of the second diffuser 190b through the communicating portion 205c, continuously cooling the motor <NUM>, so that the motor <NUM> may be operated at a relatively low temperature.

Accordingly, an increase in electrical resistance due to a high temperature of the motor <NUM> may be restricted, and thus the power of the motor <NUM> may be improved.

Claim 1:
A motor assembly comprising:
an impeller (<NUM>);
a first diffuser (<NUM>) provided at a downstream side of the impeller (<NUM>);
a second diffuser (<NUM>) provided at a downstream side of the first diffuser (<NUM>);
an impeller cover (<NUM>) coupled to the second diffuser (<NUM>) and accommodating the impeller (<NUM>) and the first diffuser (<NUM>); and
a motor (<NUM>) provided at a downstream side of the second diffuser (<NUM>) and configured to rotate the impeller (<NUM>),
wherein the second diffuser (<NUM>) includes:
a hub (<NUM>),
an outer wall (<NUM>) positioned outside the hub (<NUM>) and being concentric with the hub (<NUM>), and
a plurality of blades (<NUM>), each of the plurality of blades (<NUM>) having a first side connected to the hub (<NUM>) and a second side connected to the outer wall (<NUM>),
wherein the impeller cover (<NUM>) is coupled to the outer wall of the second diffuser (<NUM>), and
wherein a communicating portion (<NUM>) is provided at the hub (<NUM>) of the second diffuser (<NUM>) and allows an inside of the hub (<NUM>) of the second diffuser (<NUM>) to be in communication with an outside of the hub (<NUM>) of the second diffuser (<NUM>),
wherein the hub (<NUM>) of the second diffuser (<NUM>) includes a bearing accommodating portion (<NUM>).