KR102380924B1 - Rotor assembly and motor including the same - Google Patents

Abstract

The present invention includes a rotor core including a plurality of teeth radially formed from the core portion, a rotor portion including a first coil wound on the teeth, and a rotor cover covering the rotor portion, wherein the rotor cover comprises the Disclosed are a rotor assembly covering a rotor part and including a plurality of wing parts protruding in an axial direction, and a motor including the same.

Description

Rotor assembly and motor including same

The present invention relates to a rotor assembly that is easy to manufacture.

In general, a vehicle is provided with a starter motor for driving an engine and an alternator for generating electricity using the rotational force of the engine.

In the starter motor, the ignition switch is connected to the power of the battery by the driver's manipulation when the vehicle is started, and power is supplied to the starter motor through this, and the driving force generated rotates the engine to start the starter motor.

The alternator is connected to the driving unit of the engine, and the rotor rotates in a state in which a magnetic field is formed through the driving force of the engine to generate AC power, and the battery is charged using a rectifier or the like.

These starter motors and alternators are both composed of a stator and a rotor and have very similar structures, so it can be operated as a generator or a starter motor depending on whether power is applied or applied to one motor. there is.

Recently, research on a BSG structure capable of simultaneously performing the roles of a starter motor and an alternator with one structure is active.

Since the motor generates heat during rotation, it is important to quickly dissipate the generated heat to the outside in order to prevent deterioration of the motor performance. For this, a separate fan may be attached to the rotor of the BSG motor.

However, when assembling a separate mechanism to the rotor, there is a problem in that the manufacturing process is complicated, and there is an inconvenience in that the coil inside the rotor needs to be separately coated (varnished).

The present invention provides a rotor assembly having a simple manufacturing process by insert-injecting the rotor cover.

A rotor assembly according to one aspect of the present invention includes: a rotor part including a rotor core including a plurality of teeth radially formed from the core part, and a first coil wound around the teeth; and a rotor cover that covers the rotor part, wherein the rotor cover covers the rotor part and includes a plurality of wing parts protruding in an axial direction.

In the rotor assembly according to one aspect of the present invention, the rotor cover may be made of a non-conductive material.

In the rotor assembly according to one aspect of the present invention, the rotor cover may include an upper plate, a lower plate, and a connection part connecting the upper plate and the lower plate, and the connection part may be formed in a space between the plurality of teeth.

In the rotor assembly according to one aspect of the present invention, the upper plate and the lower plate include the wing portion.

In the rotor assembly according to an aspect of the present invention, the thermal conductivity of the rotor cover may be 0.35 W/m ·°C or more.

In the rotor assembly according to one aspect of the present invention, a heat dissipation groove may be formed in the upper or lower plate of the rotor cover.

In the rotor assembly according to one aspect of the present invention, the first angle formed by the tangent of the imaginary line extending the outer end of the wing part and the first imaginary circle is the tangent of the imaginary line extending the inner end of the wing part and the second imaginary circle greater than the second angle formed, the centers of the first virtual circle and the second virtual circle are the same as the center of the rotor part, and the tangent line of the first virtual circle is a tangent line at the point where the first virtual circle and the outer end meet and the tangent line of the second virtual circle may be a tangent line at a point where the second virtual circle and the inner end meet.

In the rotor assembly according to one aspect of the present invention, the first imaginary circle may be a circle connecting the outer ends of the plurality of wing parts, and the second imaginary circle may be a circle connecting the inner ends of the plurality of wing parts.

A rotor assembly according to another aspect of the present invention includes: a rotor unit including a plurality of slits formed on a side surface in a longitudinal direction; and a rotor cover that covers one surface and the other surface of the rotor part, and the slit, wherein the rotor cover includes a plurality of wing parts, and may be injection molded into the rotor part.

In the rotor assembly according to another aspect of the present invention, the rotor unit includes a rotor core including a plurality of teeth radially formed from the core portion, and a first coil wound around the teeth.

In the rotor assembly according to another aspect of the present invention, the rotor cover includes an upper plate and a lower plate on which the wing portion is formed, and the upper plate and the lower plate include at least one groove.

A method for manufacturing a rotor assembly according to one aspect of the present invention includes: manufacturing a rotor unit including a rotor core including a plurality of teeth radially formed from the core, and a first coil wound around the teeth; and injection molding the rotor cover including a plurality of wing parts by placing the rotor part in a mold and injecting resin.

In the method of manufacturing a rotor assembly according to an aspect of the present invention, in the injection molding step, the resin may be filled in a space between the plurality of teeth.

In the method for manufacturing a rotor assembly according to one aspect of the present invention, the thermal conductivity of the resin may be 0.35 W/m ·°C or more.

A motor according to one aspect of the present invention includes a housing; a stator unit disposed in the housing; the aforementioned rotor assembly; and a rotating shaft integrally rotating with the rotor assembly.

According to the present invention, the manufacturing process is simplified by insert-injecting the rotor cover.

In addition, since the resin is filled inside the rotor during injection, a separate coil coating process may be omitted.

1 is a perspective view of a motor according to an embodiment of the present invention;
Figure 2 is a cross-sectional view in the direction AA of Figure 1,
3 is a reference diagram for explaining a process in which heat is emitted from a motor according to an embodiment of the present invention;
4A to 4C are views for explaining a manufacturing process of a rotor assembly according to an embodiment of the present invention;
5 is a cross-sectional view in the BB direction of FIG. 4c,
6 is a conceptual diagram illustrating an angle of a wing portion of a rotor assembly according to an embodiment of the present invention.
7 is a flowchart illustrating a method of manufacturing a rotor assembly according to an embodiment of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

In the present invention, terms such as "comprises" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

In addition, it should be understood that the accompanying drawings in the present invention are enlarged or reduced for convenience of description.

Now, the present invention will be described in detail with reference to the drawings, and the same or corresponding components are assigned the same reference numerals regardless of reference numerals, and redundant description thereof will be omitted.

1 is a perspective view of a motor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view in the AA direction of FIG. 1, and FIG. 3 is a reference for explaining a process in which heat is emitted from the motor according to an embodiment of the present invention It is also

1 and 2 , the motor according to the present invention includes a housing 100 having a plurality of through holes 111 and 121 formed on an outer peripheral surface thereof, a stator part 300 supported by the housing 100 , and a stator and a rotor assembly 200 disposed inside the portion 300 .

When the motor according to the present invention operates as an alternator, the pulley 600 is rotated by driving the engine to rotate the rotor assembly 200 to generate alternating current. The generated alternating current is converted into direct current and can be supplied to external parts (battery, etc.). Conversely, when the motor operates as a starter, the belt pulley 600 may be rotated while the rotor assembly 200 is rotated by an externally applied current to drive external components (eg, an engine).

The housing 100 includes a first housing 110 disposed on one side of the stator part 300 and a second housing 120 disposed on the other side of the stator part 300 . The first housing 110 and the second housing 120 include a plurality of through-holes 111 and 121 formed along the circumferential direction. The through-holes 111 and 121 function as heat dissipating units for discharging heat generated inside the motor to the outside.

A protrusion (not shown) coupled to the outer surface of the stator part 300 may be formed on inner peripheral surfaces of the first housing 110 and the second housing 120 , respectively.

The stator unit 300 includes a stator core 310 and a second coil 320 wound around the stator core 310 . A portion of the stator core 310 may be exposed between the first housing 110 and the second housing 120 . Accordingly, the heat generated in the stator unit 300 may be easily discharged to the outside. However, the present invention is not necessarily limited thereto, and the stator part 300 may be disposed inside the housing 100 .

The rotor assembly 200 includes a rotor part 210 and a rotor cover 220 covering the rotor part 210 . The rotor unit 210 rotates by electromagnetic interaction with the stator unit 300 , and includes a rotor core 211 and a first coil 212 . However, the configuration of the rotor unit 210 is not necessarily limited thereto, and a magnet may be attached to the inner or outer circumferential surface of the rotor core 211 .

The rotor cover 220 rotates integrally with the rotor unit 210 . The rotor cover 220 includes wing portions 225 protruding from one side and the other side. The wing 225 serves as a cooling fan that generates a gas flow when the rotor assembly 200 rotates. The wing portion 225 may have a predetermined curvature so as to easily generate a gas flow.

Referring to FIG. 3 , when the rotor assembly rotates, a gas flow occurs inside the motor by the wing part 225 . Accordingly, the heat generated in the rotor unit 210 is rapidly discharged to the outside through the through hole 111 formed in the first housing 110 . This structure is advantageous for a motor that generates a large amount of heat due to high-speed rotation.

Referring back to FIG. 2 , the rotation shaft 400 rotates integrally with the rotor assembly 200 . One end and the other end of the rotation shaft 400 are supported by the first bearing 510 and the second bearing 520 . A belt pulley 600 that transmits power to the outside may be coupled to an end of the rotation shaft 400 .

A terminal unit 410 for applying power to the first coil 212 wound around the rotor core 211 is disposed on the rotation shaft 400 . The terminal unit 410 includes a first terminal 411 electrically connected to an end of the first coil 212 , and a second terminal 412 connected to the first terminal 411 and exposed to the outside.

4A to 4C are views for explaining a manufacturing process of a rotor assembly according to an exemplary embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along the line B-B of FIG. 4C .

Referring to FIG. 4A , the rotor part 210 includes a core part 211a and a rotor core 211 including a plurality of teeth 211b radially formed from the core part 211a, and the teeth 211b are wound on the rotor part 210 . A first coil 212 is included.

The plurality of teeth 211b includes a protrusion branched from an end thereof, and a slit S is formed between adjacent teeth. An end of the first coil 212 is electrically connected to the first terminal 411 .

Referring to FIG. 4B , the rotor unit 210 is disposed between the first mold 1 and the second mold 2 . Injection holes 1a and 2a are formed in the first mold 1 and the second mold 2 , and the resin is filled into the mold inner space H. In this case, the rotor unit 210 may be insert-injected in a state in which the rotation shaft 400 is coupled.

A shape corresponding to the shape of the rotor cover 220 may be formed in the first mold 1 and the second mold 2 , and the rotor cover 220 may be formed by insert injection. According to this configuration, it is possible to easily manufacture the wing portion 225 by insert injection without assembling separate parts. The rotor cover 220 has a shape in which one surface and the other surface are symmetrical to each other.

Referring to FIG. 4C , the rotor cover 220 covers one surface, the other surface, and slits formed on the side surfaces of the rotor part 210 . That is, the rotor cover 220 entirely covers the remaining portion except for a portion of the side surface of the rotor unit 210 . Since the rotor cover 220 is ejected while the end of the first coil 212 is fixed to the first terminal 411 , the coupling force between the first coil 212 and the first terminal 411 is improved.

The rotor cover 220 includes an upper plate 221 and a lower plate 222 , and a connection part 223 connecting the upper plate 221 and the lower plate 222 . A plurality of wing portions 225 are formed on the upper plate 221 and the lower plate 222 of the rotor cover 220 .

The rotor cover 220 may be made of a material having a thermal conductivity of 0.35 W/m ·°C or higher. Also, the tensile strength of the rotor cover 220 may be 140 MPa or more at room temperature (23° C.) and 60 MPa or more at high temperature (150° C.). When the above conditions are satisfied, the rotor cover 220 has excellent heat dissipation and excellent coupling force of the rotor unit during high-speed rotation. Specifically, the material of the rotor cover 220 may be polyphenylene sulfide (PPS) or engineering plastics (EP).

In order to increase heat dissipation performance, a plurality of heat dissipation grooves 224 may be formed in the upper plate 221 and the lower plate 222 . In addition, grooves or protrusions corresponding to the shape of the resin supply nozzle may be formed on the upper plate 221 and the lower plate 222 .

Referring to FIG. 5 , a first coil 212 is wound around the teeth 211b , and an insulating member 213 is disposed between the teeth 211b and the first coil 212 . Here, the slit S may be defined as an interval between the protrusions 211c protruding from both sides of the teeth 211b.

At this time, the connecting portion 223 of the rotor cover 220 is filled between the plurality of teeth 211b on which the first coil 212 is wound. Accordingly, the operation of separately varnishing the first coil 212 may be omitted. In addition, due to the connection part 223 of the rotor cover 220, the risk of detachment of the coil is reduced even during high-speed rotation. Since the rotor cover 220 is made of a non-conductive material, there is no risk of short circuit. The end 223a of the connection part may cover a portion of the outer peripheral surface of the protrusion 211c protruding from both sides of the tooth 211b.

6 is a conceptual diagram illustrating an angle of a wing portion of a rotor assembly according to an embodiment of the present invention.

Referring to FIG. 6 , the wing portion 225 has a first angle θ1 formed by an imaginary line L1 extending from the outer end 225a and a tangent PL1 of the first imaginary circle C1 to the wing portion ( The tangent line PL2 of the imaginary line L2 extending the inner end 225b of the 225 and the second imaginary circle C2 may be formed to be greater than a second angle θ2. The first angle θ1 is an angle of an outlet through which heat is emitted, and the second angle θ2 is an angle of an entrance through which heat is received.

Here, the first imaginary circle C1 is a circle connecting the outer ends 225a of the plurality of wing units, and the second imaginary circle C2 is a circle connecting the inner ends 225b of the plurality of wing units. . Accordingly, the centers of the first imaginary circle C1 and the second imaginary circle C2 are the same as the center P of the rotor part.

The tangent line PL1 of the first imaginary circle is a tangent at the point where the first imaginary circle C1 and the outer end 225a of the wing part meet, and the tangent line PL2 of the second imaginary circle is the second imaginary circle C2 It may be a tangent line at the point where the inner end 225b and the inner end 225b meet. A tangent line is defined as a line perpendicular to the radius of the imaginary circle at the point where it meets the imaginary circle.

The plurality of wing portions 225 may be formed radially with respect to the center of the first fixing plate 222 and inclined in the rotation direction R of the motor. That is, as it extends from the inner end 225b to the outer end 225a of the wing portion 225 based on the drawings, the motor may be inclined in a rotating direction. However, the present invention is not necessarily limited thereto and may be inclined opposite to the direction of rotation of the motor.

The spacing between the plurality of wings 225 may be equally spaced as a whole, or may be equally spaced only in a specific section. The wing portion 225 may have a substantially straight shape, but may have a predetermined curvature if only the condition that the first angle θ1 is greater than the second angle θ2 is satisfied.

Table 1 is a table measuring the flow rate (unit: ccm) of the gas flow generated in the motor rotating at 10000 rpm according to the first angle (θ1) and the second angle (θ2), and Table 2 is the first angle (θ1) ) and the second angle (θ2), a table measuring noise (unit: dB) in a motor rotating at 6000 rpm.

θ2\θ1 50 55 60 25 2.4 2.5 2.65 30 2.3 2.78 2.7 35 2.7 2.34 2.79

θ2\θ1 50 55 60 25 72 73.5 72.2 30 71 72 72.4 35 70.8 71 77

As shown in Tables 1 and 2, when the first angle θ1 is greater than 50° and less than 60°, and the second angle θ2 is greater than 25° and less than 35°, the gas flow rate is about 2.78ccm. It can be seen that the heat dissipation efficiency increases, while the noise decreases to 72 dB. That is, it can be confirmed that the flow rate of the gas is controlled according to the change of the first angle and the second angle under the same conditions.

7 is a flowchart illustrating a method of manufacturing a rotor assembly according to an embodiment of the present invention.

4 and 7 , in the method for manufacturing a rotor assembly according to an embodiment of the present invention, the rotor core 211 including a plurality of teeth 211b radially formed from the core portion 211a, and the teeth ( manufacturing the rotor part 210 including the first coil 212 wound around 211b), and placing the rotor part 210 in the molds 1 and 2 and injecting resin into the plurality of wing parts 225 ) and injecting the rotor cover 220 including the.

In the step S10 of manufacturing the rotor part, the first coil 212 is wound around the teeth 211b of the rotor core 211 , and the end of the first coil 212 is electrically connected to the terminal 411 .

In the step of injecting the rotor cover 220 ( S20 ), the rotor part 210 is placed in the molds 1 and 2 and resin is injected. The molding surfaces of the molds 1 and 2 have a shape corresponding to the rotor cover 220 . At this time, the resin is filled in the upper and lower portions of the rotor unit 210 and the empty space portions (slits between the teeth, etc.). After that, the resin is cured and the molds 1 and 2 are removed to complete the process.

100: housing
200: rotor assembly
210: rotor unit
220: rotor cover
225: wing
300: stator part
400: axis of rotation

Claims (18)

a rotor part including a rotor core including a plurality of teeth radially formed from the core part, and a first coil wound around the teeth; and
It includes a rotor cover that covers the rotor part,
The rotor cover covers the rotor part and includes a plurality of wing parts protruding in the axial direction,
The rotor cover includes an upper plate, a lower plate, and a connecting portion connecting the upper plate and the lower plate,
The connection part is filled in a space between the plurality of teeth on which the first coil is wound,
The upper plate, the lower plate, and the connecting portion of the rotor cover are made of a non-conductive material,
The first angle formed by the tangent of the imaginary line extending the outer end of the wing and the first imaginary circle is greater than the second angle formed by the tangent of the imaginary line extending the inner end of the wing and the second imaginary circle,
The centers of the first virtual circle and the second virtual circle are the same as the center of the rotor part,
The tangent line of the first virtual circle is a tangent line at the point where the first virtual circle and the outer end meet,
The tangent line of the second imaginary circle is a tangent line at a point where the second imaginary circle and the inner end meet.
delete delete According to claim 1,
The upper plate and the lower plate rotor assembly including the wing portion.
According to claim 1,
The rotor assembly has a thermal conductivity of 0.35 W/m ·°C or more of the rotor cover.
According to claim 1,
A rotor assembly in which a heat dissipation groove is formed in an upper plate or a lower plate of the rotor cover.
delete According to claim 1,
The first virtual circle is a circle connecting the outer ends of the plurality of wing parts,
The second virtual circle is a rotor assembly that connects the inner ends of the plurality of wing parts.
a rotor unit including a plurality of slits formed on a side surface in a longitudinal direction; and
It includes a rotor cover that covers one surface and the other surface of the rotor part, and the slit,
The rotor cover includes a plurality of wing parts, and is injection molded into the rotor part,
The first angle formed by the tangent of the imaginary line extending the outer end of the wing and the first imaginary circle is greater than the second angle formed by the tangent of the imaginary line extending the inner end of the wing and the second imaginary circle,
The centers of the first virtual circle and the second virtual circle are the same as the center of the rotor part,
The tangent line of the first virtual circle is a tangent line at the point where the first virtual circle and the outer end meet,
The tangent line of the second imaginary circle is a tangent line at a point where the second imaginary circle and the inner end meet.
10. The method of claim 9,
The rotor assembly includes a rotor core including a plurality of teeth formed radially from the core portion, and a first coil wound around the teeth.
10. The method of claim 9,
The rotor cover includes an upper plate and a lower plate on which the wing portion is formed,
The upper and lower plates of the rotor assembly include at least one groove.
delete delete delete housing;
a stator unit disposed in the housing;
12. A rotor assembly according to any one of claims 1, 4 to 6, and 8 to 11;
A motor comprising a rotating shaft integrally rotating with the rotor assembly.
16. The method of claim 15,
The housing is
a first housing disposed on one side of the stator part; and
A motor including a second housing disposed on the other side of the stator part.
17. The method of claim 16,
A portion of the rotor assembly is exposed between the first housing and the second housing.
16. The method of claim 15,
The housing includes a plurality of heat dissipation parts.

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