Patent Description:
An electric motor or motor (hereinafter, "motor") is an apparatus that can convert electric energy into mechanical energy.

For example, motors may include a stator and a rotor configured to rotate with respect to the stator.

In some cases, the motor is made up of a motor assembly that further includes an impeller and a frame to generate pressure or to facilitate a flow of air during rotation.

More specifically, the motor assembly includes an impeller, a stator provided at one side of the impeller, a rotor that is rotatably installed with respect to the stator and is configured to rotate the impeller, and a frame coupled to an outer surface of the stator.

An impeller housing in which the impeller is accommodated is coupled to the frame.

Bearings are provided at both sides of a rotating shaft of the rotor, respectively.

One of the bearings is provided at the frame, and the other one is supported by a bracket that is coupled to the frame.

The frame is provided with a stator fixing part (or portion) that is coupled to the outer surface of the stator, and the bracket is coupled to the stator fixing part.

The stator includes a stator core, a stator coil wound around the stator core, and an insulator for insulating the stator core and the stator coil.

A printed circuit board (PCB) that supplies driving power to the stator is coupled to the insulator of the stator.

However, in such a conventional motor assembly, performance may be decreased by an increase in air flow loss due to parts (or components) disposed in a flow path of air moved by the impeller.

In addition, as the stator fixing part extends along an axial direction, an air flow stagnant zone may be generated in a periphery of the stator fixing part, causing an increase in flow path loss.

A decrease in width of the stator fixing part, which is to reduce the flow path loss caused by the air flow stagnant zone around the stator fixing part, may cause a reduction in a coupling force (bearing force) between the bearings, the impeller, and the PCB. As a result, a clearance of parts coupled to the frame may be increased, and unnecessary vibration and noise may be caused.

Further, as the stator fixing part is configured to axially protrude from a body of the frame having a ring shape, some of air that has passed through the body is spread or diffused in a radial direction. Then, the component that flows in the axial direction may be reduced, leading to performance degradation.

Document <CIT> relates to a motor of a vacuum cleaner, the motor comprising a housing, an impeller provided inside the housing, a guide vane disposed at one side of the impeller, a stator provided at one side of the guide vane, a rotor rotatably accommodated in the stator, and a motor housing which is coupled to the housing and configured to accommodate the stator to be coupled therewith.

The present disclosure describes an electric motor assembly that can reduce an air flow loss.

The present disclosure also describes an electric motor assembly that can suppress formation of a flow stagnant zone of air moved by an impeller.

The present disclosure also describes an electric motor assembly that can secure coupling between parts (components) and suppress generation of vibration and noise.

The present disclosure also describes an electric motor assembly that can suppress radial diffusion of air and formation of an air flow stagnant zone.

Implementations disclosed herein provide an electric motor assembly that includes a stator fixing part. The stator fixing part that is coupled to an outer surface of a stator is inclined with respect to an axial direction.

More specifically, a stator is provided at one side of an impeller, a rotor configured to rotate the impeller may be disposed at an inside of the stator. The stator fixing part that is coupled to an outside of the stator is.

inclined in the axial direction so as to correspond to a rotational component of air moved by the impeller, and thus, formation of an air flow stagnant zone where air moved by the impeller remains over an extended period may be suppressed.

Here, the stator fixing part may be provided in plurality to be spaced apart from one another along a circumferential direction.

In some implementations, the plurality of stator fixing parts may be three in number.

Thus, the stator may be securely supported.

According to one aspect of the subject matter described in this application, an electric motor assembly includes: an impeller; a plurality of vanes disposed at one side of the impeller along an axial direction; a stator disposed at one side of the plurality of vanes along the axial direction; a rotor rotatably disposed with respect to the stator and configured to rotate the impeller; and a frame coupled to an outside of the stator along a radial direction. The frame includes a body having a cylindrical shape, disposed at the outside of the stator, and provided therein with an air flow path; and a plurality of stator fixing parts protruding from an inner surface of the body so as to be coupled to the stator. The plurality of stator fixing parts is disposed to be inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller.

Accordingly, formation of a flow stagnant zone of air moved by the impeller may be suppressed to thereby reduce an air flow loss. This may lead to performance improvement.

The plurality of vanes and the plurality of stator fixing parts are disposed to be inclined in substantially the same direction. Implementations according to this aspect may include one or more of the following features.

Accordingly, the occurrence of air flow loss due to the rotational component of air moved by the impeller may be suppressed.

In some implementations, a first bearing may be provided between the plurality of vanes and the rotor along the axial direction, and the frame may include a first bearing accommodating portion in which the first bearing is accommodated.

This may allow the first bearing to be securely supported to thereby suppressing transverse displacement of the first bearing.

In some implementations, the frame may include a plurality of bridges radially connected to an outer surface of the first bearing accommodating portion, and the plurality of bridges may be formed to correspond to the plurality of stator fixing parts in number and angular location.

This may result in suppressing a flow loss of air moved by the impeller.

In some implementations, the plurality of vanes may be disposed in a circumference of a vane hub to be spaced apart from each other along a circumferential direction, and the vane hub may include a penetrating portion in which the first bearing accommodating portion is accommodated.

As the vane hub and the first bearing overlap with each other in the axial direction, an axial length of the electric motor assembly may be reduced.

In some implementations, the vane hub may include a plurality of bridge accommodating portions in which the plurality of bridges is respectively inserted along the axial direction.

As the vane hub and the frame overlap with each other in the axial direction, an axial length of the electric motor may be reduced, and transverse displacement (clearance) may be suppressed.

In some implementations, the plurality of bridges may each include: a vane hub contact section that radially protrudes from the body of the frame and is in contact with the vane hub, and a vane hub coupling section that is bent to axially protrude from the vane hub contact section and is coupled to the vane hub in an axially overlapping manner.

In some implementations, the plurality of bridges may each include a fixing member coupling portion to which a fixing member that has passed through the vane hub is coupled.

Accordingly, an axial clearance between the vane hub and the frame may be suppressed or reduced.

In some implementations, a second bearing disposed at an opposite side of the impeller with the rotor interposed therebetween along the axial direction, and a bracket that accommodates and supports the second bearing may be further provided.

As the first bearing and the second bearing are provided on both sides of the rotor along the axial direction, a transverse clearance of the rotor may be suppressed or reduced.

Accordingly, an air gap between the stator and the rotor may be uniformly or constantly maintained, and the output of the electric motor assembly may be enhanced.

In some implementations, the bracket may be coupled to the frame.

Accordingly, predetermined or preset positions of the rotor, and the first bearing and the second bearing disposed on the both sides of the rotor with respect to the stator may be securely maintained.

In some implementations, the frame may be provided with a plurality of legs that is respectively disposed at outer sides of the stator fixing parts in the axial direction and is coupled to the bracket.

Accordingly, the bracket may be supported by the plurality of stator fixing parts and the plurality of legs, and thus, a support force of the frame and the bracket may be increased.

In some implementations, the plurality of legs may each have one side surface along a circumferential direction that is inclined with respect to the axial direction so as to correspond to the plurality of stator fixing parts.

Accordingly, flow resistance of air moved by the impeller may be suppressed.

In some implementations, the plurality of legs may each have another side surface along a circumferential direction that extends in the circumferential direction with respect to the plurality of stator fixing parts.

Accordingly, radial diffusion of air moved by the impeller may be suppressed.

As a result, axial flow of air moved by the impeller may be increased, leading to performance improvement.

In addition, as support strength of the plurality of legs is increased, transverse displacement of the bracket may be further suppressed.

In some implementations, the plurality of legs may each have one side surface inclined with respect to the axial direction and another side surface in parallel with the axial direction.

This may prevent the plurality of legs from being excessively extended in the circumferential direction.

In some implementations, the bracket may include a second bearing disposed at an opposite side of the impeller with the rotor interposed therebetween along the axial direction, and a plurality of frame coupling parts that radially protrudes from an outer surface of the second bearing accommodating portion and is coupled to the frame.

Accordingly, an increase in air flow resistance caused by the bracket may be effectively suppressed.

In some implementations, the plurality of legs may be longer in axial length than the plurality of the stator fixing parts with respect to the body.

Accordingly, transverse (radial) displacement of the bracket that is coupled to ends of the plurality of stator fixing parts and ends of the plurality legs may be suppressed.

In some implementations, the plurality of frame coupling parts of the bracket may each include a leg contact portion in contact with an end of one of the plurality of legs and a stator fixing part contact portion in contact with an end of one of the plurality of stator fixing parts.

In some implementations, a fixing member coupling portion may be formed through the bracket in the axial direction so as to allow a fixing member to be coupled thereto along the axial direction,.

In some implementations, the plurality of stator fixing parts may each include a female threaded portion to which the fixing member is coupled.

This may allow the frame and the bracket to be closely coupled to each other in the axial direction. As a result, they may not be arbitrarily separated from each other.

In some implementations, the plurality of stator fixing parts may each have one side surface with a linear shape that is inclined with respect to the axial direction and another side surface with a curved shape that has a circumferential width gradually increasing.

Accordingly, an increase in flow resistance due to the rotational component of air moved by the impeller may be suppressed, and a contact area with the bracket that is coupled to the plurality of stator fixing parts may be increased to thereby enhance a coupling force.

In some implementations, an impeller housing having an air inlet formed at one side thereof and in which the impeller is accommodated may be further provided.

This may allow air in a region at the front of the impeller to be smoothly sucked in and to flow smoothly.

In some implementations, the impeller housing may include an impeller accommodating portion in which the impeller is accommodated, a vane accommodating portion in which the plurality of vanes is accommodated, and a frame accommodating portion to which one side of the frame is accommodated and coupled.

The frame may allow the impeller housing to be securely supported at a predetermined position, enabling smooth air intake and smooth air flow to be archived. Further, noise generation may be suppressed.

According to the implementations disclosed herein, a frame includes a body that is disposed at an outside of a stator and has an air flow path formed therein, and a plurality of stator fixing parts that protrudes from an inner surface of the body and is coupled to an outer surface of the stator. The plurality of stator fixing parts are disposed to be inclined in an axial direction so as to correspond to the rotational component of air moved by the impeller, and thus, an increase in flow resistance of air moved by the impeller may be suppressed.

Also, an air flow loss may be reduced by suppressing formation of an air flow stagnant zone due to a stagnant flow of air moved by the impeller.

In addition, a plurality of vanes and the plurality of stator fixing parts are disposed to be inclined in substantially the same direction to thereby reduce a flow loss of air moved by the impeller.

Further, a plurality of vanes may be disposed in a circumference of a vane hub, and the vane hub may include a plurality of bridge accommodating portions so as to allow a plurality of bridges to be respectively inserted therein along the axial direction. This may allow an axial length of the electric motor assembly to be reduced.

As the frame is provided with a plurality of legs that is respectively disposed at outer sides of the plurality of stator fixing parts and is coupled to the bracket, a support force of the bracket may be increased.

As each of the plurality of legs has one side surface inclined with respect to the axial direction, a flow loss of air moved by the impeller may be suppressed.

As each of the plurality of legs has another side surface with an extended width in a circumferential direction with respect to the plurality of stator fixing parts, radial diffusion of air moved by the impeller may be suppressed.

In addition, each of the plurality of legs has another side surface along a circumferential direction that extends or increases in a circumferential direction with respect to the plurality of stator fixing parts, and thus, a support force of the bracket may be increased by that much.

As the plurality of legs is longer in axial length than the plurality of stator fixing parts with respect to the body, a transverse clearance of the bracket coupled to ends of the plurality of legs and ends of the plurality of stator fixing parts may be suppressed.

Hereinafter, one or more implementations of the present disclosure will be described in detail with reference to the accompanying drawings. Herein, the same or similar elements are designated with the same or similar reference numerals, and a redundant description has been omitted. Singular expressions include plural expressions unless the context clearly indicates otherwise. In describing the present disclosure, if a detailed explanation for a related known technology or construction is considered to unnecessarily divert the main point, such explanation has been omitted but would be understood by those skilled in the art. Also, it should be understood that the accompanying drawings are merely illustrated to easily explain the concept, and therefore, they should not be construed to limit the technological concept disclosed herein by the accompanying drawings.

<FIG> is a front view of an electric motor assembly according to one implementation of the present disclosure, <FIG> is a longitudinal cross-sectional view of the electric motor assembly of <FIG>, and <FIG> is an exploded perspective of the electric motor assembly of <FIG>. As illustrated in <FIG>, an electric motor assembly <NUM> according to this embodiment includes an impeller <NUM>, a stator <NUM>, a rotor <NUM>, and a frame <NUM>.

The impeller <NUM> may be configured to suck air in an axial direction and discharge the air in a radial direction during rotation, for example.

The impeller <NUM> includes a hub <NUM> and a plurality of blades <NUM> disposed in a circumference of the hub <NUM>. The hub <NUM> may be provided at its center with a rotating shaft coupling portion to which a rotating (or rotational) shaft <NUM> to be described hereinafter is coupled.

In this implementation, the impeller <NUM> may be configured to rotate counterclockwise in the drawing, for example.

When the impeller <NUM> rotates, air substantially flows in the axial direction, and the impeller <NUM> has a rotation or rotational direction component that is rotated along a rotation direction of the impeller <NUM>.

More specifically, referring to <FIG> and <FIG>, air sucked and discharged by the impeller <NUM> is moved to be downwardly inclined in a right direction in the drawing as it flows to a downstream side (lower side in the drawing) along the axial direction.

An impeller housing <NUM> is provided at an outside of the impeller <NUM>.

The impeller housing <NUM> has, for example, a cylindrical shape with an accommodation space formed therein.

The impeller housing <NUM> may have a cylindrical shape with a hollow center, for example.

An air inlet <NUM> is formed through a central portion (or part) of the impeller housing <NUM>, so as to allow air to be sucked therein.

The impeller housing <NUM> has a diameter that gradually increases along the axial direction.

The air inlet <NUM> of the impeller housing <NUM> includes a bell mouth <NUM> having a diameter (inner diameter) that gradually increases toward an upstream side along a flow direction of air.

Accordingly, air may be smoothly introduced into the impeller housing <NUM> when the impeller <NUM> rotates.

The impeller housing <NUM> may include, for example, an impeller accommodating portion <NUM> in which the impeller <NUM> is accommodated, a vane accommodating portion <NUM> in which a plurality of vanes <NUM> to be described hereinafter is accommodated, and a frame accommodating portion <NUM> to which the frame <NUM> is accommodated and coupled.

The impeller housing <NUM> may be formed such that a diameter (inner diameter) of the vane accommodating portion <NUM> is greater than a diameter (inner diameter) of the impeller accommodating portion <NUM>, and a diameter (inner diameter) of the frame accommodating portion <NUM> is greater than the diameter (inner diameter) of the vane accommodating portion <NUM>.

A drive (or driving) motor <NUM> that allows the impeller <NUM> to be rotatably driven is provided at one side (lower side in the drawing) of the impeller <NUM> along the axial direction.

The drive motor <NUM> includes, for example, the stator <NUM> and the rotor <NUM> that is rotatable with respect to the stator <NUM> and is configured to rotate the impeller <NUM>.

The stator <NUM> may include a stator core <NUM> and a stator coil <NUM> wound on the stator core <NUM>.

The stator core <NUM> may be formed by stacking a plurality of electrical steel sheets <NUM> in an insulating manner, for example.

The plurality of electrical steel plates <NUM> of the stator core <NUM> is provided with a rotor accommodation space <NUM> in which the rotor <NUM> is rotatably accommodated. The rotor <NUM> is ratably accommodated in the rotor accommodation space <NUM> with a predetermined air gap G from the stator <NUM>.

A flat surface 224a with a rectangular shape is formed on an outer surface of the stator <NUM> (stator core <NUM>) in a cut manner.

Accordingly, a space (air flow cross-sectional area) between the frame <NUM> and the stator <NUM> may be increased.

The flat surface 224a of the stator <NUM> may be provided in plurality to be spaced apart from one another along a circumferential direction, for example.

The flat surfaces 224a of the stator <NUM> may be spaced apart from each other by the same angle (interval), for example.

The outer surface of the stator <NUM> (stator core <NUM>) may include three flat surfaces 224a so that three circumferential surfaces 224b having an arcuate shape and three flat surfaces 224a are alternately arranged.

Each of the plurality of electrical steel plates <NUM> of the stator core <NUM> includes a plurality of teeth <NUM> protruding in a radial direction and provided therein with the rotor accommodation space <NUM>, and a plurality of slots <NUM> formed between the teeth <NUM>.

In this example, the plurality of teeth <NUM> and slots <NUM> are alternately disposed, and the stator <NUM> is provided with three teeth <NUM> and three slots <NUM>.

The flat surfaces 224a of the stator <NUM> may be, for example, formed at outside of the teeth <NUM> of the stator <NUM>, respectively.

The stator coil <NUM> may be implemented as concentrated winding intensively wound around the teeth <NUM>, for example.

The stator coil <NUM> may include a plurality of coil portions 230a that respectively corresponds to phases (U phase, V phase, and W phase) of a three-phase AC power supply, for example. In this implementation, the plurality of coil portions 230a may be three in number. As each of the plurality of coil portions 230a is intensively wound around one of the plurality of teeth <NUM>, the plurality of coil portions 230a may each have two ends. Here, one end of each coil portion 230a may be connected to a power source, and another end of each coil portion 230a may be connected at one point (neutral point).

The stator <NUM> includes an insulator <NUM> for insulating the stator core <NUM> and the stator coil <NUM>.

The insulator <NUM> may be configured to block an inner surface and both axial end surfaces of the stator core <NUM>.

Accordingly, a short circuit caused by direct contact between the stator coil <NUM> and the stator core <NUM> may be suppressed.

The insulator <NUM> may be configured to block inner surfaces of the plurality of slots <NUM> of the stator core <NUM>, and circumferential surfaces (upper, lower, and both side (lateral) surfaces) of the plurality of teeth <NUM> for insulating the stator coil <NUM>.

The insulator <NUM> may be divided into two parts or portions so as to be coupled to face each other along the axial direction, for example. In this implementation, the insulator <NUM> may include an upper insulator 250a that is coupled at an upper side of the stator core <NUM> and a lower insulator 250b that is coupled at a lower side of the stator core <NUM> in the drawing.

The insulator <NUM> is provided with PCB coupling portions <NUM> each extending in the axial direction and coupled to a PCB <NUM> to be described hereinafter.

One ends (power lines) of the coil portions 230a of the stator coil <NUM> are connected to the PCB coupling portions <NUM>, respectively. The one ends (power lines) of the coil portions 230a that are respectively connected to the PCB coupling portions <NUM> may be connected to respective phases (U-phase, V-phase, and W-phase) of an electric circuit of the PCB <NUM> in a corresponding manner.

Accordingly, AC power may be supplied to each of the coil portions 230a of the stator coil <NUM>.

The PCB coupling portions <NUM> may be spaced apart from one another along the circumferential direction, for example.

The PCB coupling portions <NUM> may be three in number, for example.

The insulator <NUM> may be provided with a neutral point connecting portion <NUM> (see <FIG> and <FIG>) for forming a neutral point that integrally connects the other ends of the three coil portions 230a together.

The rotor <NUM> may include the rotating shaft <NUM>, the rotor core <NUM> that rotates about the rotating shaft <NUM>, and a permanent magnet <NUM> that is provided at the rotor core <NUM>. Here, when a size of the rotor <NUM> is relatively small, the rotor core <NUM> may not be provided, and instead, the permanent magnet <NUM> may be coupled to the rotating shaft <NUM>.

The rotor core <NUM> may be formed by, for example, stacking the plurality of electric steel plates <NUM> in an insulating manner. The rotor core <NUM> may have an outer surface with a circular shape, and the permanent magnet <NUM> may be coupled to the outer surface (circumferential surface) of the rotor core <NUM>. The permanent magnet <NUM> may be configured such that different magnetic poles (N poles and S poles) are alternately disposed along the circumferential direction.

The rotor <NUM> may include end plates <NUM> respectively coupled to both ends of the rotor core <NUM> along the axial direction.

The end plates <NUM> may each have an increased outer diameter relative to an outer diameter of the rotor core <NUM>.

The end plates <NUM> may be in contact with both ends of the permanent magnet <NUM>, respectively.

Accordingly, axial separation of the permanent magnet <NUM> may be suppressed. The rotating shaft <NUM> may extend to both sides of the rotor core <NUM> along the axial direction.

The rotating shaft <NUM> may be provided with a plurality of bearings <NUM> disposed at both sides of the rotor <NUM> (rotor core <NUM>), respectively.

Accordingly, transverse displacement of the permanent magnet <NUM> may be suppressed.

With this configuration, transverse displacement of the rotor <NUM> may be suppressed, allowing the air gap G between the stator <NUM> and the rotor <NUM> to be constantly or uniformly maintained.

As a result, vibration and noise generated when the rotor <NUM> rotates may be suppressed, and the output of the electric motor assembly <NUM> may be enhanced.

The plurality of bearings <NUM> may include a first bearing 300a that is disposed between the impeller <NUM> and the rotor core <NUM>, and a second bearing 300b that is disposed at an opposite side of the first bearing 300a with the rotor core <NUM> interposed therebetween.

The first bearing 300a and the second bearing 300b may be configured as ball bearings, for example.

The first bearing 300a and the second bearing 300b may each include, for example, an outer ring <NUM>, an inner ring <NUM> concentrically disposed inside the outer ring <NUM>, and a plurality of balls <NUM> disposed between the outer ring <NUM> and the inner ring <NUM>.

The rotating shaft <NUM> extends further from the first bearing 300a along the axial direction, and an impeller coupling portion 275a to which the impeller <NUM> is coupled is provided at an end (or end portion) of the rotating shaft <NUM>.

The impeller coupling portion 275a is formed at one end (upper end in the drawing) of the rotating shaft <NUM>.

A guide vane <NUM> that guides air moved by the impeller <NUM> is provided at one side of the impeller <NUM> along the axial direction.

The guide vane <NUM> includes, for example, a vane hub <NUM> having a circumferential surface and the plurality of vanes <NUM> disposed to be spaced apart from one another on a circumferential surface of the vane hub <NUM>.

The plurality of vanes <NUM> is disposed to be inclined with respect to the axial direction.

In detail, the plurality of vanes <NUM> is disposed to be inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>. Each of the plurality of vanes <NUM> is downwardly inclined to the right substantially.

The vane hub <NUM> has a disk (or disc) shape with a relatively thin thickness relative to its diameter.

The vane hub <NUM> has an outer diameter greater than a rotation diameter of the impeller <NUM>, for example.

The plurality of vanes <NUM> may each include, for example, an upstream section 151a and a downstream section 151b along the flow direction of air.

The upstream sections 151a and the downstream sections 151b of the plurality of vanes <NUM> may have different inclination angles with respect to the axial direction.

Each of the plurality of vanes <NUM> may be configured such that the upstream section 151a is more inclined than the downstream section 151b with respect to the axial direction.

Here, the upstream section 151a may have a curved shape, and the downstream section 151b may have a shape relatively close to a linear shape, for example.

The frame <NUM> is coupled to an outer side of the stator <NUM>.

The frame <NUM> may include a body <NUM> disposed at an outside of the stator <NUM> and having an air flow path formed therein, and a plurality of stator fixing parts <NUM> protruding from an inner surface of the body <NUM> and coupled to the stator <NUM>.

The body <NUM> may have an inner diameter greater than an outer diameter of the stator <NUM>, for example.

The plurality of stator fixing parts <NUM> may each protrude from the inner surface of the body <NUM> so as to be coupled to the outer surface of the stator <NUM> in a surface contact manner, for example.

The plurality of stator fixing parts <NUM> may be formed to correspond to the plurality of teeth <NUM> so as to be disposed between the teeth <NUM> of the stator <NUM>, for example.

Accordingly, an occurrence of flow loss of air moved by rotation of the impeller <NUM> may be suppressed.

The plurality of stator fixing parts <NUM> may be three in number, for example.

The plurality of stator fixing parts <NUM> is disposed to be inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>.

The plurality of stator fixing parts <NUM> and the plurality of vanes <NUM> may be disposed to be inclined in the same direction.

Accordingly, an increase in flow resistance of air moved by the impeller <NUM> may be suppressed.

Thus, an air flow loss caused by the plurality of vanes <NUM> and stator fixing parts <NUM> may be suppressed to thereby enhance air flow performance of the electric motor assembly <NUM>.

The frame <NUM> is provided with a first bearing accommodating portion <NUM> to which the first bearing 300a is accommodated and coupled.

The frame <NUM> includes a plurality of bridges <NUM> each having one end connected to the body <NUM> and another end connected to the first bearing accommodating portion <NUM>.

The plurality of bridges <NUM> may be radially connected to the first bearing accommodating portion <NUM>, respectively.

The plurality of bridges <NUM> may be formed at upper ends of the stator fixing parts <NUM>, respectively.

Accordingly, the flow loss of air moved by rotation of the impeller <NUM> may be suppressed.

The plurality of bridges <NUM> may be three in number, for example.

The plurality of bridges <NUM> may be coupled to the guide vane <NUM>, for example.

The plurality of bridges <NUM> may each include, for example, a vane hub contact section 380a that radially protrudes from the body <NUM> of the frame <NUM> and is in contact with the vane hub <NUM>.

The plurality of bridges <NUM> may each include, for example, a vane hub coupling section 380b that is coupled to the vane hub <NUM> in an overlapping manner.

As the first bearing accommodating portion <NUM> of the frame <NUM> and the guide vane <NUM> are coupled to each other in an overlapping manner along the axial direction, an axial length of the electric motor assembly <NUM> may be reduced to that much.

With this configuration, a distance between the impeller <NUM> and the rotor <NUM> may be reduced, and thus, transverse displacement during rotation of the impeller <NUM> may be suppressed.

The vane hub coupling section 380b may be bent to protrude outward from the vane hub contact section 380a along the axial direction.

Here, the first bearing accommodating portion <NUM> may protrude further from the vane hub coupling section 380b to a predetermined length in the axial direction.

Accordingly, the first bearing 300a accommodated in the first bearing accommodating portion <NUM> may be disposed closer to the impeller <NUM>.

As the impeller <NUM> is supported in a manner of suppressing the transverse displacement, the impeller <NUM> may be rotated in a more stable or secure manner.

The plurality of bridges <NUM> may each include a fixing member coupling portion <NUM> to which a fixing member <NUM> (see <FIG>) is coupled. For example, the fixing member <NUM> may include a male threaded portion, and the fixing member coupling portion <NUM> may have a female threaded portion, allowing them to be coupled to each other.

A penetrating portion (e.g., through-hole) <NUM> in which the first bearing accommodating portion <NUM> is inserted may be formed through a central portion of the guide vane <NUM> in the axial direction.

A plurality of fixing member coupling portions <NUM> is formed in a circumference of the penetrating portion <NUM> of the guide vane <NUM> in a penetrating manner, so as to allow the fixing members <NUM> to be coupled along the axial direction.

A bracket <NUM> that accommodates and supports the second bearing 300b is provided at one side (lower side in the drawing) of the rotor <NUM> along the axial direction.

The bracket <NUM> includes, for example, a second bearing accommodating portion <NUM> in which the second bearing 300b is accommodated, and a frame coupling part <NUM> having one end connected to an outer surface of the second bearing accommodating portion <NUM> and another end connected to the frame <NUM>.

The PCB <NUM> is disposed at one side (lower side in the drawing) of the bracket <NUM>.

The PCB <NUM> may be electrically connected to the stator coil <NUM> and configured to supply three-phase AC power with different frequencies, for example.

Accordingly, a rotational speed (revolutions per minute (RPM)) of the rotor <NUM> may be variously adjusted.

The PCB <NUM> may have, for example, a disk shape.

The PCB <NUM> may be supported by being coupled to the PCB coupling portions <NUM> of the insulator <NUM>, for example.

The PCB <NUM> may have an outer diameter that corresponds to the outer diameter of the stator <NUM>, for example. The PCB <NUM> may include, for example, a substrate 450a and a plurality of circuit parts (or components) 450b that is provided at the substrate 450a and constitutes an electric circuit.

<FIG> is a bottom perspective view of a guide vane of <FIG>. As illustrated in <FIG>, the penetrating portion <NUM> is formed through the central portion of the guide vane <NUM>. Bridge accommodating portions <NUM> are provided in a circumference of the penetrating portion <NUM> in a recessed manner so as to allow the plurality of bridges <NUM> of the frame <NUM> to be inserted therein in the axial direction. The vane hub coupling sections 380b of the plurality of bridges <NUM> are insertedly coupled to the bridge accommodating potions <NUM>, respectively.

The fixing member coupling portions <NUM> may be formed through the bridge accommodating portions <NUM>, respectively.

<FIG> is an enlarged perspective view of a frame of <FIG>, <FIG> is a front view of a frame of <FIG>, and <FIG> illustrates an outer surface of the frame of <FIG>. As illustrated in <FIG>, the frame <NUM> includes the body <NUM> with a ring shape and the plurality of stator fixing parts <NUM> protruding from the inner surface of the body <NUM> and extending in the axial direction.

The body <NUM> may be concentrically disposed with respect to the stator <NUM>.

The body <NUM> is spaced apart from the stator <NUM> in the axial direction.

The impeller housing <NUM> may be coupled to an outer surface of the body <NUM>.

The body <NUM> and the impeller housing <NUM> may be disposed concentrically with respect to each other.

The first bearing accommodating portion <NUM> is provided at a central portion of the body <NUM>, and the plurality of bridges <NUM> is provided between the body <NUM> and the first bearing accommodating portion <NUM>.

The body <NUM> and the first bearing accommodating portion <NUM> may be concentrically disposed with respect to each other.

The first bearing accommodating portion <NUM> protrudes from the body <NUM> along the axial direction.

The plurality of stator fixing parts <NUM> is provided inside the body <NUM>.

An inner surface (end circumferential surface along the radial direction) of the stator fixing part <NUM> is in surface contact with the outer surface of the stator <NUM> (stator core <NUM>).

The inner surface of the stator fixing part <NUM> has a cross section with an arcuate shape so as to be in surface contact with a circumferential surface of the stator core <NUM>.

The plurality of stator fixing parts <NUM> is formed to correspond to the plurality of bridges <NUM>.

The plurality of stator fixing parts <NUM> is respectively formed at one side (lower side in the drawing) of the plurality of bridges <NUM> along the axial direction.

In this implementation, three bridges <NUM> are provided, and accordingly, three stator fixing parts <NUM> are provided to correspond to the three bridges <NUM>.

Each of the plurality of stator fixing parts <NUM> is disposed at one side (lower side in the drawing) of one of the plurality of bridges <NUM> inside the body <NUM>.

The plurality of bridges <NUM> may be disposed at upper sides of the plurality of stator fixing parts <NUM>, respectively.

Accordingly, when the impeller <NUM> is driven, air flow resistance caused by the plurality of bridges <NUM> and stator fixing parts <NUM> may be minimized.

A stator contact portion <NUM> in contact with the stator <NUM> is formed at one side (lower side in the drawing) of each vane hub contact section 380a of each bridge <NUM>.

The stator contact portion <NUM> is in contact with one end (upper end in the drawing) of the insulator <NUM> along the axial direction.

The stator contact portion <NUM> may have a triangular shape, for example.

The stator contact portions <NUM> may respectively protrude from the plurality of bridges <NUM> to one side along the circumferential direction.

The stator fixing parts <NUM> may each protrude from the inner surface of the body <NUM> so as to be in surface contact with the outer surface of the stator <NUM> (stator core <NUM>).

One or both side (or lateral) surfaces of each of the stator fixing parts <NUM> are inclined with respect to the axial direction so as to correspond to the rotational component of air moved by rotation of the impeller <NUM>.

In this implementation, since the impeller <NUM> is configured to rotate counterclockwise in the drawing, of the both side surfaces of the stator fixing part <NUM>, one side surface (first side surface) <NUM> where air moved by rotation of the impeller <NUM> reaches first is inclined downward to one side (in the right direction in the drawing).

Another side surface (second side surface) <NUM> of each of the stator fixing parts <NUM> may have a linear cross section or a curved cross section.

Here, the first side surface <NUM> of the stator fixing part <NUM> may be referred to as an "upstream end" and the second side surface <NUM> may be referred to as a "downstream end" with respect to a flow of air moved by the impeller <NUM>.

The stator fixing part <NUM> may have a width that increases toward one side (lower side in the drawing) along the axial direction, for example.

In detail, the first side surfaces <NUM> of the stator fixing parts <NUM> may each have a linear cross section, and the second side surfaces <NUM> may each have a straight cross section or a curved cross section.

A circumferential width of the stator fixing part <NUM> may increase in the axial direction so that its one end (lower end in the drawing) is wider than its another end (upper end in the drawing).

Accordingly, a contact area with the bracket <NUM> may be increased, allowing a coupling force to be enhanced.

The another side surface (second side surface <NUM>) of each of the stator fixing parts <NUM> may be inclined with respect to the axial direction, so as to correspond to the rotational component of air moved by the impeller <NUM>.

As a result, an air flow stagnant zone (stagnation point) where air moved by the impeller <NUM> remains over an extended period may be significantly reduced in a downstream region of the stator fixing part <NUM> with respect to the flow of air moved by the impeller <NUM>.

A fixing member coupling portion <NUM> is formed at an end (lower end) of each of the stator fixing parts <NUM> so that a fixing member <NUM> coupled to the bracket <NUM> in a manner of passing therethrough is coupled (see <FIG>).

The fixing member coupling portions <NUM> of the stator fixing parts <NUM> may each include a female threaded portion so as to allow a male threaded portion of the fixing member <NUM> that has passed through the bracket <NUM> to be coupled thereto.

The body <NUM> may be provided with a plurality of legs <NUM>, each formed at an outer side of one of the stator fixing parts <NUM> in a manner of extending along the axial direction.

In this implementation, like the first side surfaces <NUM> of the stator fixing parts <NUM>, an upstream side (first side surface <NUM>) of each of the plurality of legs <NUM> with respect to the flow direction of air moved by rotation of the impeller <NUM> is inclined with respect to the axial direction, so as to correspond to the rotational component of air moved by the impeller <NUM>.

Accordingly, the flow loss of air moved by the impeller <NUM> may be significantly reduced.

The leg <NUM> may be integrally formed with the stator fixing part <NUM> (single body), for example.

As a result, strength of the stator fixing part <NUM> may be increased (reinforced).

Each of the plurality of legs <NUM> may have the same radial width as the body <NUM>.

The plurality of legs <NUM> may be formed to correspond to the number of stator fixing parts <NUM>.

In this implementation, the plurality of legs <NUM> may be three in number the same as the stator fixing parts <NUM>.

Outer surfaces of the plurality of legs <NUM> may be disposed on an extended line of the outer surface of the body <NUM>.

The outer surfaces of the plurality of legs <NUM> may each have an arcuate shape.

That is, each of the plurality of legs <NUM> may have an outer diameter the same as an outer diameter of the body <NUM>.

The plurality of legs <NUM> may protrude from the body <NUM> to be longer than the stator fixing parts <NUM> in the axial direction.

Ends of the plurality of legs <NUM> may protrude longer than ends of the stator fixing parts <NUM> in a down direction (lower side) in the drawing.

The fixing member coupling portions <NUM> may be provided at ends (lower ends) of the stator fixing parts <NUM>, respectively.

The fixing member coupling portion <NUM> of the stator fixing parts <NUM> may each include, for example, the female threaded portion so as to correspond to the male threaded portion of the fixing member <NUM>.

A circumferential thickness of the leg <NUM> may be greater than a circumferential thickness of the stator fixing part <NUM>.

This may allow a coupling force between the frame <NUM> and the bracket <NUM> to be increased.

With this configuration, a downstream side (second side surface <NUM>) of the leg <NUM> may be located downstream than the second side surface <NUM> of the stator fixing part <NUM> with respect to the flow of air moved by rotation of the impeller <NUM>.

The second side surface <NUM> of the leg <NUM> may be disposed along the axial direction, for example.

Here, a lower end width of the leg <NUM> may be equal to a lower end width of the stator fixing part <NUM>, for example.

With this configuration, a portion having a substantially triangular shape that extends from an upper region of the stator fixing part <NUM> of the leg <NUM> in the circumferential direction is formed, and the portion of the leg <NUM> having the triangular shape may be defined as a reinforcing portion <NUM> since it increases overall support strength of the leg <NUM> (see <FIG>).

Thus, a coupling force between the frame <NUM> and the bracket <NUM> may be enhanced.

In addition, as the reinforcing portion <NUM> suppresses radial diffusion of air that has passed through the body <NUM> by the impeller <NUM>, allowing a straight component of air moved by the impeller <NUM> to be increased. As a result, performance of air flow in the axial direction by rotation of the impeller <NUM> may be enhanced.

<FIG> is an enlarged perspective view of a bracket of <FIG>, <FIG> is a front view of the bracket of <FIG>, <FIG> illustrates an exterior of the bracket of <FIG>, <FIG> is a planar view of the bracket of <FIG>, and <FIG> is a bottom view of the bracket of <FIG>. As illustrated in <FIG>, the bracket <NUM> includes the second bearing accommodating portion <NUM> to which the second bearing 300b is accommodated and coupled, and the frame coupling part <NUM> having one end connected to the second bearing accommodating portion <NUM> and another end coupled to the frame <NUM>.

The second bearing accommodating portion <NUM> has a cylindrical shape with one side (upper side in the drawing) open.

The second bearing accommodating portion <NUM> is formed such that a side facing the rotor <NUM> is open.

A through-hole <NUM> is formed on another side of the second bearing accommodating portion <NUM>.

Accordingly, heat exchange (heat dissipation) between an inside and an outside of the second bearing accommodating portion <NUM> may be facilitated.

An outer diameter of the through-hole <NUM> of the second bearing accommodating portion <NUM> may be less (or smaller) than an outer diameter of the inner ring <NUM> of the second bearing 300b, for example.

The frame coupling part <NUM> may be coupled to the stator fixing part <NUM> of the frame <NUM>, for example.

The frame coupling part <NUM> may extend from the second bearing accommodating portion <NUM> in the radial direction and be spaced apart in the circumferential direction.

The frame coupling part <NUM> may be provided in plurality so as to correspond to the number of stator fixing parts <NUM>.

In this implementation, three frame coupling parts <NUM> may be provided to correspond to the three stator fixing parts <NUM>.

The frame coupling parts <NUM> may each include, for example, a radial section <NUM> that radially extends from the second bearing accommodating portion <NUM> and a bent section <NUM> that is bent from the radial section <NUM> and is disposed in the axial direction.

Here, the second bearing accommodation portion <NUM> protrudes longer than the radial section <NUM> in the axial direction.

The bent section <NUM> may include, for example, an inclined portion 412a that extends outwardly to be inclined more than the radial section <NUM> and an axial portion 412b that is bent from the inclined portion 412a and is disposed in the axial direction.

In the depicted example, the bent section <NUM> includes the inclined portion 412a and the axial portion 412b. However, this is just an example, and the bent section <NUM> may be configured to only have the axial portion 412b.

The outer surface of the second bearing accommodating portion <NUM> may include an inclined surface <NUM> that is inclined toward the frame coupling part <NUM>.

Accordingly, a support force of the second bearing accommodating portion <NUM> may be increased, allowing transverse displacement of the second bearing 300b to be suppressed.

The frame coupling part <NUM> may include, for example, a leg contact portion <NUM> in contact with an end of the leg <NUM> of the frame <NUM> and a stator fixing part contact portion <NUM> in contact with an end of the stator fixing part <NUM> of the frame <NUM>.

The leg contact portion <NUM> may be in surface contact with the end of the leg <NUM>.

The stator fixing part contact portion <NUM> may be in surface contact with the end of the stator fixing part <NUM>.

The leg contact portion <NUM> may be disposed at an outside of the stator fixing part contact portion <NUM>.

The stator fixing part contact portion <NUM> protrudes longer than the leg contact portion <NUM> in the axial direction.

The leg contact portion <NUM> and the stator fixing part contact portion <NUM> define a stair shape.

The leg contact portion <NUM> and the stator fixing part contact portion <NUM> may protrude longer than the second bearing accommodating portion <NUM> in the axial direction.

Fixing member coupling portions <NUM> may be formed through the bracket <NUM> (frame coupling parts <NUM>) so that the fixing members <NUM> coupled to the frame <NUM> are respectively coupled thereto.

The fixing member coupling portions <NUM> of the bracket <NUM> may each have an extended portion 420a in which a head of the fixing member <NUM> is inserted.

The fixing member coupling portions <NUM> may be provided at the inclined portions 412a of the bracket <NUM>, respectively.

Here, an upstream surface <NUM> of the frame coupling part <NUM> of the bracket <NUM>, with respect to the flow of air moved by the impeller <NUM>, may be inclined in the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>, for example.

The upstream surface <NUM> of the frame coupling part <NUM> of the bracket <NUM> may include a cut (or cutout) portion 422a which is cut in an inclined manner so as to correspond to the upstream surface (first side surface <NUM>) of the stator fixing part <NUM>.

An upstream surface of the leg contact portion <NUM> and an upstream surface of the stator fixing part contact portion <NUM> may be, for example, cut in an inclined manner so as to correspond to the first side surface <NUM> of the leg <NUM> and the first side surface <NUM> of the stator fixing part <NUM>, respectively.

A downstream surface of the frame coupling part <NUM> of the bracket <NUM> with respect to the flow of air, may be disposed along the axial direction, for example.

<FIG> is an exploded view showing examples of a frame, a stator, and a bracket of <FIG>, <FIG> is a bottom perspective view of the frame, the stator, and the bracket of <FIG>, and <FIG> is a planar view illustrating an example of a coupled state between the frame, the stator, and the bracket of <FIG>. As illustrated in <FIG> and <FIG>, when coupling the stator <NUM> and the rotor <NUM> together, and coupling the frame <NUM> and the bracket <NUM> together, the leg <NUM> of the stator <NUM> is disposed to face one side (lower side in the drawing), and the frame <NUM> is disposed at an upper side of the stator <NUM>. Then, the first bearing 300a is disposed to face the frame <NUM> (upper side) inside the stator <NUM> so that the rotor <NUM> is accommodatingly disposed. The bracket <NUM> is disposed at a lower side of the rotor <NUM>.

The stator fixing part <NUM> of the frame <NUM> is disposed to correspond to a circumferential surface of the stator <NUM>, and the stator <NUM> and the frame <NUM> are moved relative to each other in the axial direction. When the stator fixing part <NUM> comes in surface contact with the outer surface of the stator <NUM>, the stator fixing part <NUM> is coupled to the outer surface of the stator <NUM> while sliding relative to it.

The first bearing 300a may be insertedly couped to an inside of the first bearing accommodating portion <NUM> of the frame <NUM>.

When an upper end of the stator <NUM> is brought into contact with the stator contact portion <NUM> of the frame <NUM>, insertion is limited or restricted. Then, the coupling is completed.

Referring to <FIG>, of the outer surface of the stator <NUM>, each of the stator fixing parts <NUM> is coupled to an outer circumferential surface having an arcuate shape, and a flow path (or passage) P of air moved by rotation of the impeller <NUM> is formed between the plurality of bridges <NUM>.

The air flow path P between the inner surface of the body <NUM> of the frame <NUM> and the stator <NUM> may have an increased cross-sectional area of air flow owing to the flat surface 224a of the outer surface of the stator <NUM>.

The plurality of legs <NUM> and the plurality of stator fixing parts <NUM> may protrude downward of the stator <NUM>.

The leg contact portions <NUM> and the stator fixing part contact portions <NUM> of the bracket <NUM> are disposed to correspond to the legs <NUM> and the stator fixing parts <NUM>, respectively, so that the second bearing 300b is axially pressed against an entrance (or inlet) of the second bearing accommodating portion <NUM> to make them close to each other.

The second bearing 300b is insertedly coupled to an inside of the second bearing accommodating portion <NUM>, and the legs <NUM> and the stator fixing parts <NUM> may be coupled to the corresponding leg contact portions <NUM> and the corresponding stator fixing part contact portions <NUM> in a surface contact manner, respectively. The PCB coupling portions <NUM> of the stator <NUM> may each protrude downward of the bracket <NUM>.

When relative movement between the frame <NUM> and the bracket <NUM> is stopped, the fixing member coupling portion <NUM> of the stator fixing part <NUM> and the fixing member coupling portion <NUM> of the bracket <NUM> may communicate with each other. The fixing members <NUM> are respectively inserted into the fixing member coupling portions <NUM> and the fixing member coupling portions <NUM> in communication with each other, and then the fixing members <NUM> are rotated to be coupled to the respective fixing member coupling portions <NUM> of the stator fixing parts <NUM>.

When the coupling of the bracket <NUM> is completed, the PCB <NUM> is disposed at a lower side of the bracket <NUM>, and the PCB <NUM> is disposed to be in contact with ends of the PCB coupling portions <NUM> of the stator <NUM>, allowing the PCB coupling portions <NUM> and the PCB <NUM> to be integrally fixed and coupled to each other. Power lines of phases (U phase, V phase, and W phase) of the PCB coupling portions <NUM> may be electrically connected to the PCB <NUM>.

The guide vane <NUM> may be coupled to an upper side of the frame <NUM>. The guide vane <NUM> is coupled to upper ends of the plurality of bridges <NUM>, and the guide vane <NUM> is integrally fixed and coupled to the frame <NUM> by the fixing member <NUM>.

Then, the impeller <NUM> is coupled to an end of the rotating shaft <NUM> of the rotor <NUM> penetrating through the guide vane <NUM>, and the impeller housing <NUM> is coupled such that the impeller <NUM> can be accommodated therein. The body <NUM> of the frame <NUM> is accommodatingly coupled to an inside of the frame accommodating portion <NUM> of the impeller housing <NUM>.

<FIG> illustrates a flow of air in the electric motor assembly of <FIG>, and <FIG> illustrates a flow of air in an electric motor assembly of the related art.

When operation is started and power is applied to the stator coil <NUM>, a rotating magnetic field produced by the stator coil <NUM> and a magnetic field produced by the permanent magnet <NUM> of the rotor <NUM> interact with each other, allowing the rotor <NUM> to be rotated about the rotating shaft <NUM>. When the rotor <NUM> rotates, the impeller <NUM> is rotated about the rotating shaft <NUM>.

When the impeller <NUM> rotates, air outside the impeller housing <NUM> is sucked through the air inlet <NUM>. The air sucked into the impeller housing <NUM> is discharged in the radial direction by the plurality of blades <NUM> of the impeller <NUM>, and is then guided in the axial direction by the impeller housing <NUM> and the guide vane <NUM>.

In detail, as shown in <FIG>, the air discharged by the impeller <NUM> flows in the axial direction by an inner surface of the impeller housing <NUM>, an outer surface of the vane hub <NUM>, and the plurality of vanes <NUM> while moving to be downwardly inclined to the right in the drawing along a rotation direction of the impeller <NUM>.

Here, with respect to the flow of air moved by the impeller <NUM>, the upstream surface (first side surface <NUM>) of the stator fixing part <NUM> is inclined in the axial direction so as to correspond to the rotational component of air, thereby suppressing an air flow loss.

In addition, the second side surface <NUM> (downstream surface) of the stator fixing part <NUM> is inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>, allowing an air flow stagnant zone (A: cross-sectional area) to be reduced.

As a result, a flow loss of the air moved by the impeller <NUM> may be significantly reduced.

Referring to <FIG>, an electric motor assembly <NUM> of the related art in which a stator fixing part is disposed along an axial direction includes an impeller <NUM>, an impeller housing <NUM>, and a stator fixing part <NUM> disposed in the axial direction. With respect to a flow of air moved by rotation of the impeller <NUM>, an upstream surface of the stator fixing part <NUM> is disposed in the axial direction, and thus, air flow resistance may be significantly increased due to contact with the rotational component of air moved by the impeller <NUM>.

In addition, with respect to the flow of air, as a downstream surface of the stator fixing part <NUM> is disposed along the axial direction, an air flow stagnant zone (A1: cross-sectional area) with a relatively large triangular shape may be generated in a downstream region of the stator fixing part <NUM>. Accordingly, in the case of the related art motor assembly <NUM>, flow performance of air moved by the impeller <NUM> may be reduced.

<FIG> is a front view of an electric motor assembly according to another implementation of the present disclosure, and <FIG> is a front view of a frame of <FIG>. An electric motor assembly 100a of this implementation includes an impeller <NUM>, a stator <NUM>, a rotor <NUM>, a frame 350a, and a bracket 400a.

The stator <NUM> includes a stator core <NUM>, a stator coil <NUM> wound around the stator core <NUM>, and an insulator <NUM> disposed between the stator core <NUM> and the stator coil <NUM>, as described above.

The rotor <NUM> is provided inside the stator <NUM>.

The rotor <NUM> may include a rotating shaft <NUM>, a rotor core <NUM> that is coupled to the rotating shaft <NUM>, and a permanent magnet <NUM> that is coupled to the rotor core <NUM>, as described above.

A first bearing 300a and a second bearing 300b that rotatably support the rotating shaft <NUM> are provided at both sides of the rotor <NUM>, respectively.

The frame 350a may be coupled to the stator <NUM>.

The frame 350a includes, for example, a body <NUM> having a ring shape and a stator fixing part 360a that protrudes from an inner surface of the body <NUM> and is coupled to an outer surface of the stator <NUM> in a surface contact manner.

The stator fixing part 360a is inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>, for example.

The stator fixing part 360a may be three in number so as to be disposed between three teeth <NUM>, for example.

The stator fixing part 360a may have a constant or same thickness along the circumferential direction.

The impeller <NUM> is coupled to one end (upper end in the drawing) of the rotating shaft <NUM>.

A guide vane <NUM> for guiding air moved by the impeller <NUM> is provided between the impeller <NUM> and the rotor <NUM>.

The guide vane <NUM> includes a vane hub <NUM> and a plurality of vanes <NUM> disposed in a circumference of the vane hub <NUM>, as described above.

An impeller housing <NUM> is provided at an outside of the impeller <NUM>. The impeller housing <NUM> may include an impeller accommodating portion <NUM> in which the impeller <NUM> is accommodated, a vane accommodating portion <NUM> in which the guide vane <NUM> is accommodated, and a frame coupling part 410a to which the frame 350a is accommodatingly coupled.

A bracket 400a that accommodates and supports the second bearing 300b is coupled to the frame 350a.

A PCB <NUM> is provided at one side (lower side in the drawing) of the bracket 400a. The PCB <NUM> includes, for example, a substrate 450a having a disk shape and a plurality of circuit parts 450b that is provided at the substrate 450a and constitutes an electric circuit. The PCB <NUM> is coupled to a PCB coupling portion <NUM> formed at the insulator <NUM> of the stator <NUM>.

As illustrated in <FIG> and <FIG>, the frame 350a includes a first bearing accommodating portion <NUM> protruding upwards of the body <NUM> along the axial direction and to which the first bearing 300a is accommodated and coupled. The body <NUM> is provided with a plurality of bridges <NUM> having one end connected to the inner surface of the body <NUM> and another end connected to the first bearing accommodating portion <NUM>.

In this implementation, the stator fixing part 360a has a constant thickness along the circumferential direction. However, this is just an example, and the stator fixing part 360a may have a thickness that gradually increases downward along the axial direction.

A lower end of the stator fixing part 360a may be in surface contact with the bracket 400a.

The bracket 400a of the electric motor assembly 100a of this example has a structure similar to the bracket <NUM> of the example described above. The bracket 400a includes a second bearing accommodating portion <NUM> to which the second bearing 300b is accommodated and coupled, and the frame coupling part 410a having one end connected to an outer surface of the second bearing accommodating portion <NUM> and another end coupled to the stator fixing part 360a of the frame 350a.

The frame coupling part 410a of the bracket 400a of this example includes a radial section <NUM> that radially extends from the outer surface of the second bearing accommodating portion <NUM> and a bent section <NUM> that is bent from the radial section <NUM>, is disposed in the axial direction, and includes an inclined portion 412a extending from the radial section <NUM> in an inclined manner and an axial portion 412b bent from the inclined portion 412a and disposed along the axial direction. The axial portion 412b may have a contact surface with a size that corresponds to a contact surface of the lower end of the stator fixing part 360a.

A cut portion 422a may be formed at an upstream surface of the bracket 400a with respect to a flow of air moved by rotation of the impeller <NUM>, so as to correspond to the rotational component of air moved by the impeller <NUM>. The cut portion 422a may be disposed on an extended line of a first side surface <NUM> of the stator fixing part 360a.

When operation is started and power is applied to the stator <NUM>, a magnetic field produced by the stator coil <NUM> and a magnetic field produced by a permanent magnet <NUM> of the rotor <NUM> interact with each other, allowing the rotor <NUM> to be rotated about the rotating shaft <NUM>. As the rotating shaft <NUM> rotates, the impeller <NUM> is rotated.

When the impeller <NUM> rotates, air is sucked into the impeller housing <NUM>, and the sucked air is discharged along a radial direction of the impeller <NUM>. The air discharged by the impeller <NUM> is guided by an inner surface of the impeller housing <NUM> and the guide vane <NUM> to flow downward along the axial direction.

Here, the air moved by the impeller <NUM> has a rotational component that rotates in the same direction as a rotation direction of the impeller <NUM>, and the first side surface <NUM> of the stator fixing part 360a is inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>. This may result in significantly suppressing an increase in air flow resistance.

In addition, a second side surface <NUM> of the stator fixing part 360a may be inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>, and thus, formation of an air flow stagnant zone A, due to stagnant air flow, in a downstream region of the stator fixing part 360a may be significantly reduced.

As a result, air flow performance in the electric motor assembly 100a of this example may be greatly increased.

<FIG> is a front view of an electric motor assembly according to another implementation of the present disclosure, <FIG> is a front view of a frame of <FIG>, and <FIG> is a bottom perspective view of the frame of <FIG>. An electric motor assembly 100b of this implementation includes an impeller <NUM>, a stator <NUM>, a rotor <NUM>, a frame 350b, and a bracket <NUM>.

The impeller <NUM> includes a hub <NUM> and a plurality of blades <NUM> disposed in a circumference of the hub <NUM> to be spaced apart from one another.

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

The rotor <NUM> includes a rotating shaft <NUM>, a rotor core <NUM> coupled to the rotating shaft <NUM>, and a permanent magnet <NUM> coupled to the rotor core <NUM>.

The impeller <NUM> is coupled to the rotating shaft <NUM>.

A guide vane <NUM> for guiding air moved by the impeller <NUM> is provided at one side (lower side in the drawing) of the impeller <NUM>.

The guide vane <NUM> includes a vane hub <NUM> and a plurality of vanes <NUM> disposed in a circumference of the vane hub <NUM> to be spaced apart from one another.

The frame 350b is provided on an outer surface of the stator <NUM>. An impeller housing <NUM> in which the impeller <NUM> is rotatably accommodated is coupled to an upper side of the frame 350b. A bracket <NUM> that accommodates and supports a second bearing 300b is coupled to a lower side of the frame 350b. A PCB <NUM> is provided at a lower side of the bracket <NUM>.

The frame 350b of this implementation includes a body <NUM> having a ring shape and a stator fixing part 360b that protrudes from an inner surface of the body <NUM> and is coupled to the outer surface of the stator <NUM> in a surface contact manner.

The stator fixing part 360b may be three in number, so as to be disposed between three teeth <NUM> of the stator <NUM>.

The stator fixing part 360b is inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>.

The stator fixing part 360b has a constant or same thickness along the circumferential direction, for example.

The stator fixing part 360b may be formed such that a thickness of the body <NUM> side and a thickness of an end (lower end) of the stator fixing part 360b are the same.

The frame 350b of this implementation is provided with a leg 370a axially extending from the body <NUM> and is disposed at an outer side of the stator fixing part 360b.

Accordingly, deformation of the stator fixing part 360b due to an external force in a transverse direction may be suppressed.

The legs 370a is provided in plurality so as to correspond to the number of stator fixing parts 360b.

The legs 370a may be three in number so as to correspond to the three stator fixing parts 360b.

Like the examples described above, the leg 370a may protrude longer than the stator fixing part 360b in the axial direction with respect to the body <NUM>.

In this example, a first side surface <NUM> of the stator fixing part 360b and a first side surface <NUM> of the leg 370a with respect to a flow of air moved by rotation of the impeller <NUM> are inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>, allowing a flow loss of air moved by the impeller <NUM> to be suppressed.

In addition, as a second side surface <NUM> of the stator fixing part 360b and a second side surface <NUM> of the leg 370a with respect to the flow of air moved by rotation of the impeller <NUM> are inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>, formation of an air flow stagnant zone A, due to a stagnant flow of air moved by the impeller <NUM>, in a downstream region of the stator fixing part 360b and a downstream region of the leg 370a may be significantly reduced.

The bracket <NUM> includes a second bearing accommodating portion <NUM> to which the second bearing 300b is accommodated and coupled, and a plurality of frame coupling parts <NUM> that radially extends from an outer surface of the second bearing accommodating portion <NUM> and is coupled to the frame 350b.

The plurality of frame coupling parts <NUM> may each include, for example, a radial section <NUM> that radially extends from the outer surface of the second bearing accommodating portion <NUM> and a bent section <NUM> that is bent from the radial section <NUM>, is disposed in the axial direction, and includes an inclined portion 412a extending from the radial section <NUM> in an inclined manner and an axial portion 412b bent from the inclined portion 412a and disposed along the axial direction.

The plurality of frame coupling parts <NUM> of the bracket <NUM> may each include, for example, a leg contact portion <NUM> in contact with the leg 370a and a stator fixing part contact portion <NUM> in contact with the stator fixing part 360b.

A fixing member coupling portion <NUM> may be formed at the frame coupling part <NUM> so as to be integrally fixed to the frame 350b by a fixing member. The fixing member coupling portion <NUM> may have an extended portion 420a in which a head of the fixing member is accommodated.

When operation is started and power is applied to the stator <NUM>, a magnetic field produced by the stator coil <NUM> and a magnetic field produced by the permanent magnet <NUM> of the rotor <NUM> interact with each other, allowing the rotor <NUM> to be rotated with respect to the rotating shaft <NUM>. As the rotating shaft <NUM> rotates, the impeller <NUM> is rotated.

Here, the air moved by the impeller <NUM> has a rotational component that rotates in the same direction as a rotation direction of the impeller <NUM>, and the first side surface <NUM> of the stator fixing part 360b and the first side surface <NUM> of the leg 370a are inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>. This may result in significantly suppressing an increase in air flow resistance.

In addition, as the second side surface <NUM> of the stator fixing part 360b and the second side surface <NUM> of the leg 370a are inclined with respect to the axial direction so as to correspond to the rotational component of air moved by the impeller <NUM>, an air flow stagnant zone, due to stagnant air flow, in the downstream region of the stator fixing part 360b and the downstream region of the leg 370a may be significantly reduced.

Therefore, air flow performance in the electric motor assembly 100b of the present disclosure may be greatly increased.

In the foregoing, exemplary implementations of the present disclosure have been shown and described. However, it is intended that the implementations described above are not be limited by the detailed description provided herein.

Claim 1:
An electric motor assembly, comprising:
an impeller (<NUM>);
a guide vane (<NUM>) disposed at one side of the impeller (<NUM>) along an axial direction, the guide vane (<NUM>) comprising a plurality of vanes (<NUM>);
a stator (<NUM>) disposed at one side of the guide vane (<NUM>) along the axial direction;
a rotor (<NUM>) rotatably disposed with respect to the stator (<NUM>) and configured to rotate the impeller (<NUM>); and
a frame (<NUM>) coupled to an outside of the stator (<NUM>) along a radial direction,
characterized in that the frame (<NUM>) comprises:
a body (<NUM>) having a cylindrical shape, disposed at the outside of the stator (<NUM>), and provided therein with an air flow path; and
a plurality of stator fixing parts (<NUM>) protruding from an inner surface of the body (<NUM>) so as to be coupled to the stator (<NUM>),
wherein the plurality of stator fixing parts (<NUM>) is disposed to be inclined with respect to the axial direction,
an inner surface of each of the plurality of the stator fixing parts (<NUM>) has a cross section with an arcuate shape so as to be in surface contact with a circumferential surface of the stator core (<NUM>),
wherein the plurality of vanes (<NUM>) and the plurality of stator fixing parts (<NUM>) are disposed to be inclined in substantially the same direction, and
one or both side surfaces of each of the stator fixing parts (<NUM>) are inclined with respect to the axial direction so as to correspond to air moved by rotation of the impeller (<NUM>).