KR102297686B1 - Rotor and motor including the same - Google Patents

Abstract

The present invention provides a non-magnetic member including a through-hole into which a rotation shaft is inserted, a plurality of core members accommodated inside the non-magnetic member and radially disposed based on the through-hole to form a pocket, and in the pocket Disclosed is a rotor including a plurality of inserted magnets, and an outer circumferential surface of the magnets is covered by the non-magnetic member, and a motor including the same.

Description

Rotor and motor including same

The present invention relates to a rotor mounted on a motor.

In general, in a motor, the rotor is rotated by electromagnetic interaction between the rotor and the stator. At this time, the rotation shaft inserted into the rotor also rotates to generate rotational driving force.

The rotor consists of a rotor core and a magnet, and the type of rotor is divided into a surface-attached type (SPM type) and a buried type (IPM type) according to the coupling structure of the magnet installed on the rotor core.

Among them, the IPM type rotor includes a cylindrical hub into which a rotating shaft is inserted, a core member radially coupled to the hub, and a magnet inserted between the core member.

However, there is a risk of damage when the core member is forcibly pressed into the hub in the assembly process. In addition, since the hub, the core member, and the magnet are manually assembled, there is a problem in that concentricity is distorted, and there are many assembly parts, so there is a problem in that the production cost is increased.

The present invention provides a rotor having a simple assembly process and a motor including the same.

In addition, the present invention provides a rotor in which separation of the magnet is prevented and a motor including the same.

A rotor according to one aspect of the present invention comprises: a non-magnetic member including a through hole into which a rotating shaft is inserted; a plurality of core members disposed radially based on the through hole to form a pocket; and a plurality of magnets inserted into the pocket, wherein the non-magnetic member includes a central portion including the through hole, and an outer portion covering an outer circumferential surface of the magnet.

In the rotor according to one aspect of the present invention, the thickness of the center satisfies the following relational expression (1).

[Relational Expression 1]

Thickness of center (mm) ≥ (MW ×MH ×Br) / K

(Here, MW is the length (mm) of the magnet, MH is the width (mm) of the magnet, Br is the magnetic flux density (T) of the magnet, K is a constant that satisfies 5≤K≤50 and the unit is mm- is T.)

In the rotor according to one aspect of the present invention, the thickness of the central rotor has a thickness of 2mm or more.

In the rotor according to one aspect of the present invention, the outer peripheral surface of the core member may be exposed to the outside of the non-magnetic member.

In the rotor according to one aspect of the present invention, the core member includes a locking jaw protruding from an outer circumferential surface in a direction opposite to each other, and the outer circumferential surface of the magnet exposed between the locking jaws is covered by the outer side of the non-magnetic member. .

In the rotor according to one aspect of the present invention, the non-magnetic member includes a connecting portion connecting the central portion and the outer portion.

In the rotor according to one aspect of the present invention, the connection part may be formed on at least one of one surface and the other surface of the rotor.

In the rotor according to one aspect of the present invention, the central portion includes a plurality of insertion grooves formed on the outer peripheral surface and coupled to the end of the core member.

In the rotor according to one aspect of the present invention, the insertion groove is formed to extend in the axial direction, and may be formed in plurality along the outer peripheral surface of the central portion.

In the rotor according to one aspect of the present invention, the insertion groove may be formed to be wider toward the inside of the central portion.

In the rotor according to one aspect of the present invention, the non-magnetic member may be formed by injection molding integrally with the core member and the magnet.

A motor according to one aspect of the present invention includes a housing; a stator disposed inside the housing; rotor; and a rotation shaft inserted through the rotor to rotate integrally with the rotor.

According to the present invention, since the magnet is covered by the non-magnetic member, there is an advantage in that leakage magnetic flux is prevented.

In addition, since the rotor parts are integrally assembled, dimensional accuracy is improved and slip torque can be prevented.

In addition, since the rotor parts are integrally assembled, there is an advantage in that the dimensional accuracy is improved when the magnet is inserted.

In addition, it is possible to lower the production cost by the integrated assembly.

1 is a conceptual diagram of a motor according to an embodiment of the present invention;
2 is a perspective view of a rotor according to an embodiment of the present invention;
3 is a partial plan view of a rotor according to an embodiment of the present invention;
4 is a conceptual diagram for explaining the thickness of a non-magnetic member according to an embodiment of the present invention,
5 is a graph of measuring the flux density of a motor equipped with a conventional rotor and a motor equipped with a rotor according to the present invention;
6 is a perspective view showing a state in which a rotor and a rotating shaft are coupled according to an embodiment of the present invention;
7 is a perspective view showing a state in which a rotor and a rotating shaft are coupled from another direction according to an embodiment of the present invention;
8 is a conceptual diagram illustrating a state in which a non-magnetic member is injection-molded 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 conceptual diagram of a motor according to an embodiment of the present invention.

Referring to FIG. 1 , a motor according to an embodiment of the present invention includes a housing 100 , a stator 300 disposed inside the housing 100 , and a rotor 200 rotatably disposed on the stator 300 . ), and a rotating shaft 400 that is inserted through the rotor 200 and rotates integrally.

The housing 100 is formed in a cylindrical shape to provide a space in which the stator 300 and the rotor 200 can be mounted. At this time, the shape or material of the housing 100 may be variously modified, but a metal material that can withstand a high temperature well may be selected.

The housing 100 is coupled to the cover 110 to shield the stator 300 and the rotor 200 from the outside. In addition, a cooling structure (not shown) may be further included to easily dissipate internal heat. As the cooling structure, an air cooling structure or a water cooling structure may be selected, and the shape of the housing 100 may be appropriately deformed according to the cooling structure.

The stator 300 is inserted into the inner space of the housing 100 . The stator 300 includes a stator core 320 and a coil 310 wound around the stator core 320 . The stator core 320 may be an integral core formed in a ring shape, or a core in which a plurality of divided cores are combined.

The stator 300 may be appropriately deformed according to the type of the motor. For example, in the case of a DC motor, a coil may be wound around the integrated stator core, and in the case of a three-phase control motor, the U, V, and W phases may be respectively input to a plurality of coils.

The rotor 200 is rotatably disposed with the stator 300 . The rotor 200 is equipped with a magnet and rotates by electromagnetic interaction with the stator 300 .

The rotating shaft 400 is coupled to the center of the rotor 200 . Accordingly, when the rotor 200 rotates, the rotation shaft 400 also rotates. At this time, the rotating shaft 400 is supported by the first bearing 500 disposed on one side and the second bearing 600 disposed on the other side.

The circuit board 700 has a plurality of electronic components embedded therein. For example, a Hall IC (not shown) for sensing the rotation of the rotor 200 may be mounted on the circuit board 700 , or an inverter for 3-phase control may be mounted.

2 is a perspective view of a rotor according to an embodiment of the present invention, and FIG. 3 is a partial plan view of the rotor according to an embodiment of the present invention.

2 and 3 , the rotor 200 includes a non-magnetic member 210 having a cylindrical shape, a plurality of core members 220 disposed radially to form a pocket P, and a pocket P. It includes a plurality of magnets 230 to be inserted.

The non-magnetic member 210 is not particularly limited as long as it has a configuration capable of fixing the core member 220 and the magnet 230 . For example, the non-magnetic member 210 may be manufactured by injection molding in a state in which the core member 220 is radially disposed inside the mold. Then, the magnet 230 is inserted into the pocket (P). As another example, the non-magnetic member 210 may be integrally formed by injection molding together with the core member 220 and the magnet 230 . As another example, it is also possible to insert the core member 220 and the magnet 230 after prefabricating the cylindrical non-magnetic member 210 having a plurality of insertion holes formed therein.

The material of the non-magnetic member 210 can be applied without limitation as long as it is a material capable of shielding magnetic force. In this embodiment, a non-magnetic member using resin will be described.

Specifically, the non-magnetic member 210 includes a central portion 211 including a through hole 211a into which the rotation shaft 400 is inserted, an outer portion 212 covering the outer peripheral surface of the magnet 230 , and a central portion 211 . and a connector connecting the outer part 212 to each other.

The center 211 is formed with a through hole 211a into which the rotation shaft 400 is inserted. The through hole 211a may have a flat surface 211c formed on an inner wall or a long hole shape. According to this structure, there is an advantage in that it is possible to prevent the rotation shaft 400 from slipping.

The central portion 211 is in contact with the inner end of the magnet 230 to fix the magnet 230 and at the same time prevent the magnetic flux from leaking to the outside through the through hole 211a. In addition, a plurality of insertion grooves 211b to which the ends of the core member 220 are coupled are formed on the outer circumferential surface of the central portion 211 . The insertion groove 211b is formed to extend in the axial direction.

Accordingly, since the core member 220 is firmly fixed to the non-magnetic member 210 even during high-speed rotation of the motor, the problem of the magnet 230 from being detached is prevented. The insertion groove 211b may be formed (tapered) to increase in width toward the through hole 211a to increase the coupling force between the core member 220 and the central portion 211 .

The outer portion 212 is formed between the plurality of core members 220 to expose the outer circumferential surface 222 of the core member and to cover the outer circumferential surface 231 of the magnet 230 . Accordingly, the problem of the magnet 230 being separated from the pocket P and the problem of leakage magnetic flux are prevented. The outer side 212 may be bonded to the outer circumferential surface 231 of the magnet 230 depending on the manufacturing form.

The core member 220 is disposed inside the non-magnetic member 210 and is radially disposed based on the through hole 211a. The pocket P may be defined as a space formed by the central portion 211 of the non-magnetic material, the outer portion 212 , and the neighboring core member 220 .

The core member 220 is formed of a metal material to form a magnetic flux path between the magnets 230 . The inner end of the core member 220 is fixed to the insertion groove 211b of the central portion 211 , and the outer circumferential surface 222 is exposed to the outside of the non-magnetic member 210 . In this case, the exposed outer peripheral surface 222 has the same curvature as the outer diameter curvature of the non-magnetic member 210 .

On the outer peripheral surface 222 of the core member 220, a locking protrusion 221 extending in a direction facing each other to accommodate the magnet 230 may be formed. The locking jaw 221 constrains the magnet 230 not to be separated when the motor rotates.

The magnet 230 may be disposed in a magnetic flux concentration type spoke type. Specifically, the magnet 230 is magnetized in the circumferential direction and disposed so that the same polarity as that of a neighboring magnet faces. The magnet 230 may be formed such that the width W decreases toward the through hole 211a at a point where it intersects the false wire C1 having a diameter greater than the diameter of the through hole 211a.

Figure 4 is a conceptual diagram for explaining the thickness of the non-magnetic member according to an embodiment of the present invention, Figure 5 is a conventional rotor mounted motor and the rotor according to the present invention the magnetic flux density of the mounted motor This is the measured graph.

Referring to FIG. 4 , the central portion 211 is in contact with the inner end of the magnet 230 to prevent the magnetic flux of the magnet 230 from leaking to the outside through the through hole 211a. Therefore, it is preferable that the central portion 211 has a thickness such that the magnetic flux of the magnet cannot pass therethrough. Specifically, the thickness (D) of the center may satisfy Relation 1 below.

[Relational Expression 1]

Thickness of center (mm) ≥ (MW ×MH ×Br) / K

Here, MW is the length (mm) of the magnet 230 , MH is the width (mm) of the magnet 230 , and Br is the magnetic flux density (Tesla, T) of the magnet 230 . K is a constant and may have any value satisfying 5≤K≤50, and the unit is mm-T. The constant K may be adjusted to any value satisfying 5≤K≤50 in order to satisfy an appropriate thickness of the center.

That is, as the length and width of the magnet 230 and the magnetic flux density increase, the central thickness D of the non-magnetic member increases in proportion to it. At this time, it is preferable that the thickness of the center has 2 mm or more. When the thickness of the central part is less than 2 mm, it is difficult to manufacture the central part by die casting or injection molding, and there is a problem that it does not have sufficient strength.

Referring to FIG. 5, as a result of measuring the flux density of a motor equipped with a conventional rotor and a motor equipped with a rotor according to the present invention, it can be seen that the magnetic flux density of the rotor according to the present invention is high in almost all sections. can

Specifically, the conventional motor measured a magnetic flux density of about 1.17 [Tesla], while the motor equipped with a rotor according to the present invention measured a magnetic flux density of about 1.24 [Tesla], confirming that the magnetic flux density increased by about 6%. did. Accordingly, there is an advantage in that the output of the motor can be increased as much as the improved magnetic flux density.

6 is a perspective view showing a state in which a rotor and a rotating shaft are coupled according to an embodiment of the present invention, and FIG. 7 is a perspective view showing a state in which the rotor and a rotating shaft are coupled according to an embodiment of the present invention from another direction, FIG. 8 is a conceptual diagram for explaining a state in which the non-magnetic member is injection-molded according to an embodiment of the present invention.

6 to 8 , the connecting portion 213 of the non-magnetic member 210 is formed on the entire lower surface of the rotor 200 to connect the central portion 211 and the outer portion 212 . The lower surface on which the connection part 213 is formed may be a surface facing the direction in which the resin is injected during injection molding.

The magnet 230 and the core member 220 are sealed by a central portion 211 , a connecting portion 213 , and an outer portion 212 of a non-magnetic material. If necessary, the connection part 213 may be formed up to the upper surface of the rotor 200 .

According to this configuration, since the cylindrical non-magnetic member 210 and the core member 220 are integrally formed by injection molding, there is an advantage of easy assembly, and there is an advantage of reducing the slip torque.

100: housing
200: rotor
210: non-magnetic member
220: core member
230: magnet
300: stator
400: rotation axis

Claims (9)

a non-magnetic member including a through hole into which the rotating shaft is inserted;
a plurality of core members disposed radially based on the through hole to form a pocket; and
It includes a plurality of magnets inserted into the pocket,
The non-magnetic member includes a central portion including the through hole, an outer portion disposed on an outer circumferential surface of the plurality of magnets, and a connection portion connecting the central portion and the outer portion,
The plurality of magnets include a first region having a constant width in a radial direction of the rotation axis and a second region having a smaller width as it approaches the rotation axis,
a radial length of the first region is longer than a radial length of the second region;
The plurality of core members includes a first portion disposed between the first areas of the plurality of magnets and a second portion disposed between the second areas of the plurality of magnets,
The width of the first part decreases as it approaches the axis of rotation,
The second part has a constant width in the radial direction,
The thickness of the center rotor satisfies the following relational expression (1).
[Relational Expression 1]
Thickness of center (mm) ≥ (MW×MH×Br)/K
(Where MW is the length (mm) of the magnet, MH is the width (mm) of the magnet, Br is the magnetic flux density (T) of the magnet, K is a constant that satisfies 5≤K≤50 and the unit is mm- is T.)
According to claim 1,
The connecting portion connects one end of the central portion and one end of the outer portion,
The other end of the outer portion protrudes in the axial direction than the other end of the central portion.
delete According to claim 1,
The outer circumferential surface of the core member is exposed to the outside of the non-magnetic member.
5. The method of claim 4,
The core member includes a locking jaw protruding from the outer circumferential surface in a direction facing each other,
The outer circumferential surface of the magnet exposed between the locking jaws is covered by the outer side of the non-magnetic member.
According to claim 1,
The central portion is formed on the outer peripheral surface of the rotor comprising a plurality of insertion grooves coupled to the end of the core member.
7. The method of claim 6,
The insertion groove is formed to extend in the axial direction, and a plurality of rotors are formed along the outer peripheral surface of the center.
8. The method of claim 7,
The insertion groove is a rotor that becomes wider toward the inner side of the central portion.
housing;
a stator disposed inside the housing;
A rotor according to any one of claims 1, 2, 4 to 8; and
A motor including a rotating shaft inserted through the rotor to rotate integrally with the rotor.

Images