KR102674223B1 - Motor - Google Patents

Abstract

The present invention includes a rotor including a rotating shaft, a hole into which the rotating shaft is inserted, and a stator disposed outside the rotor, wherein the rotor includes a rotor core surrounding the rotating shaft and a plurality of magnets coupled to the rotor core. In addition, the magnet is disposed at a certain distance from the adjacent magnet in the axial direction of the rotation shaft, and the sum of the distance is 0.04 to 0.07 of the axial length of the stator.

Description

motor{MOTOR}

The embodiment relates to a motor in which a plurality of magnets provided in a rotor are arranged to be spaced apart from each other.

As vehicle motors gradually evolve into high-torque, high-speed specifications, robust design for the rotor structure applied to the motor is required.

The structure of a rotor used in a general motor includes a laminated rotor core formed by stacking a plurality of disk-shaped rotor core members, and a structure in which a magnet is attached to the outer surface of the rotor core is used.

Motors using such permanent magnets exhibit cogging torque. Cogging torque is the non-uniform torque of the stator that inevitably appears in motors using permanent magnets, and refers to the radial torque that moves to the position where the magnetic energy of the motor is minimum, that is, to the equilibrium state.

A sudden change in magnetic flux near the boundary between the N and S poles of a magnet generates cogging torque. Cogging torque causes noise and vibration and reduces motor performance, so it is important to reduce it. In particular, it is most important to reduce cogging torque for motors used in actuators for precise position control.

However, in a rotor where multiple magnets are attached, by applying a skew angle while each puck is attached or by simultaneously magnetizing three stages of magnets, adjacent pucks are affected during magnetization, and even after magnetization, the pucks are reversed up and down. There is a problem that the cogging torque and back electromotive force harmonics worsen due to the influence of the polarity.

Japanese Patent Publication No. 2013-099038 (May 20, 2013)

The embodiment provides a motor that allows magnets attached to the rotor core to be spaced apart.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned here will be clearly understood by those skilled in the art from the description below.

Embodiments of the present invention include: a rotating shaft; a rotor including a hole into which the rotating shaft is inserted; and a stator disposed outside the rotor, wherein the rotor includes a rotor core surrounding a rotating shaft and a plurality of magnets coupled to the rotor core, wherein the magnets are in constant contact with magnets adjacent to the axial direction of the rotating shaft. They are disposed at intervals apart from each other, and the sum of the intervals is 0.04 to 0.07 of the axial length of the stator.

It may further include a housing including the rotor and the stator.

The rotor core is composed of a plurality of rotor cores, and the rotor core may be arranged at a certain distance from adjacent rotor cores in the axial direction of the rotation shaft.

The sum of the spacing between the rotor cores may be equal to the sum of the spacing between the magnets.

The sum of the spacing between the rotor cores may be 0.04 to 0.07 of the axial length of the stator.

The sum of the spacing between the rotor cores is calculated as the sum of the first spacing and the second spacing formed by the plurality of rotor cores, and the first spacing and the second spacing may be the same.

It may include a spacer disposed between the rotor cores to form a gap between the rotor cores.

The outer diameter of the spacer may be smaller than the outer diameter of the rotor core.

The distance between the plurality of magnets and adjacent magnets may be the same.

The magnet may protrude in the axial direction of the rotation axis rather than the upper and lower surfaces of the stator.

The sum of the height of the magnet protruding from the upper surface of the stator and the height of the magnet protruding from the lower surface of the stator may be equal to the sum of the magnet spacing.

The height of the magnet protruding from the upper surface of the stator may be the same as the height of the magnet protruding from the lower surface of the stator.

The sum of the intervals may be 0.05 to 0.06.

According to the embodiment, there is an effect of improving cogging torque and back electromotive force harmonics by disposing the magnets apart.

The various and beneficial advantages and effects of the present invention are not limited to the above-described content, and may be more easily understood through description of specific embodiments of the present invention.

1 is a diagram showing the basic structure of a motor according to an embodiment of the present invention,
Figure 2 is a diagram showing a first embodiment of a rotor, which is a component of the present invention;
Figure 3 is a diagram showing a second embodiment of a rotor, which is a component of the present invention;
Figure 4 is a diagram showing a third embodiment of a rotor, which is a component of the present invention;
Figure 5 is a diagram showing the shape of a spacer, which is a component of Figure 4;
Figure 6 is an enlarged view of the internal structure of Figure 1,
Figure 7 is a diagram showing the amount of change in cogging torque according to the gap ratio of the magnet of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated and described in the drawings. However, this is not intended to limit the embodiments of the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the embodiments.

Terms containing ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a second component may be named a first component without departing from the scope of the embodiment, and similarly, the first component may also be named a second component. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the embodiments of the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that it does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

In the description of the embodiment, when an element is described as being formed “on or under” another element, (or under) includes both elements that are in direct contact with each other or one or more other elements that are formed (indirectly) between the two elements. Additionally, when expressed as "on or under", it can include not only the upward direction but also the downward direction based on one element.

Hereinafter, embodiments will be described in detail with reference to the attached drawings, but identical or corresponding components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted.

1 to 7 clearly illustrate only the main features in order to clearly understand the present invention conceptually, and as a result, various modifications of the illustration are expected, and the scope of the present invention is limited by the specific shape shown in the drawings. It doesn't have to be.

Referring to FIG. 1, the motor 1 according to an embodiment of the present invention may include a rotation shaft 100, a rotor 200, a stator 300, and a housing 400.

The rotation shaft 100 may be coupled to the rotor 200. When electromagnetic interaction occurs between the rotor 200 and the stator 300 through current supply, the rotor 200 rotates and the rotation shaft 100 rotates in conjunction with this. The rotating shaft 100 may be supported by a bearing.

The rotor 200 is disposed inside the stator 300 assembly. The rotor 200 may include a rotor core 210 and a magnet coupled to the rotor core. The rotor 200 can be divided into the following shapes depending on the method of combining the rotor core and the magnet.

The rotor 200 may be implemented as a type in which a magnet is coupled to the outer peripheral surface of the rotor core. In this type of rotor 200, a separate can member may be coupled to the rotor core to prevent the magnet from separating and increase coupling force. Alternatively, the magnet and rotor core can be double-injected to form one piece.

The rotor 200 may be implemented as a type in which a magnet is coupled to the inside of the rotor core. This type of rotor 200 may be provided with a pocket into which a magnet is inserted inside the rotor core.

Meanwhile, the rotor core can be largely of two types.

First, the rotor core may be formed by stacking a plurality of thin steel plates. At this time, the rotor core may be formed as a single piece that does not form a skew angle, or may be formed by combining a plurality of unit cores (Pucks) that form a skew angle.

Second, the rotor core may be formed in the form of a single cylinder. At this time, the rotor core may be formed as a single piece that does not form a skew angle, or may be formed by combining a plurality of unit cores (Pucks) that form a skew angle.

Meanwhile, unit cores may each include a magnet externally or internally.

The stator 300 causes electrical interaction with the rotor 200 to induce rotation of the rotor 200. A coil may be wound around the stator 300 to cause interaction with the rotor 200. The specific configuration of the stator 300 for winding the coil is as follows.

The stator 300 may include a stator 300 core including a plurality of teeth. The stator 300 core may be provided with an annular yoke, and teeth may be provided on the yoke toward the center. Teeth may be provided at regular intervals along the perimeter of the yoke. Meanwhile, the stator 300 core may be formed by stacking a plurality of thin steel plates. Additionally, the stator 300 core may be formed by combining or connecting a plurality of split cores.

The housing 400 is formed in a cylindrical shape so that the stator 300 assembly can be coupled to the inner wall. The upper part of the housing 400 may be implemented in an open state, and the lower part of the housing 400 may be implemented in a closed state. A bearing mounting space may be provided in the lower part of the housing 400 to accommodate the bearing supporting the lower part of the rotating shaft 100. A cover may be coupled to the top of the open housing 400.

Figure 2 is a diagram showing a first embodiment of a rotor, which is a component of the present invention.

Referring to FIG. 2, the rotor 200, which is a component of the present invention, includes a rotor core 210 surrounding the rotating shaft 100 and a plurality of magnets 230 coupled to the rotor core 210, and the magnets ( 230) is arranged to be spaced apart from the adjacent magnets 230 in the axial direction of the rotation axis 100 at a certain interval, and the sum of the spaced intervals of the magnets 230 is a ratio of 0.04 to 0.07 of the axial length of the stator 300. It can be arranged to have.

The purpose of the present invention is to reduce cogging torque by arranging the plurality of magnets 230 disposed on the rotor core 210 to be spaced apart in the direction of the rotation axis 100.

When the rotor core 210 is configured as an integrated piece, a plurality of magnets 230 provided in a curved shape may be arranged to have a layered structure on the outer surface of the rotor core 210. In this case, the magnet 230 may be arranged to be spaced apart from the adjacent magnets 230 at a certain interval in the axial direction of the rotation axis 100. In this case, the sum of the intervals of the magnets 230 formed from a plurality of layered structures is The stator 300 may be arranged to have an axial length ratio of 0.04 to 0.07.

At this time, the interval between the magnet 230 having a layered structure and the magnet 230 having an adjacent layered structure may be arranged to be the same.

In addition, when the rotor core 210 is composed of a plurality, the height of each rotor core 210 is provided to be higher than the height of the magnet 230, so that even when the plurality of rotor cores 210 are closely coupled to each other, the rotation shaft 100 Magnets 230 adjacent to each other in the axial direction may be spaced apart from each other at regular intervals.

Figure 3 is a diagram showing a second embodiment of the rotor 200, which is a component of the present invention.

Referring to FIG. 3, a plurality of rotor cores 210 may be provided, and the rotor cores 210 may be arranged to be spaced at a certain distance from adjacent rotor cores 210 in the axial direction of the rotation shaft 100. In this case, the spacing between the rotor cores 210 can be adjusted by press-fitting equipment.

The rotor core 210 and the magnet 230 may be provided to have the same height. When the plurality of rotor cores 210 are arranged to be spaced apart, the sum of the spacing between the rotor cores 210 may be equal to the sum of the spacing between the magnets 230.

In addition, the sum of the spacing between the rotor cores 210 is calculated as the sum of the first spacing and the second spacing formed by the plurality of rotor cores 210, and the first spacing and the second spacing may be formed at the same spacing. there is.

The sum of the spacing between the rotor cores 210 may be arranged to have a ratio of 0.04 to 0.07 of the axial length of the stator 300.

FIG. 4 is a diagram showing a third embodiment of the rotor 200, which is a component of the present invention, and FIG. 5 is a diagram showing the shape of the spacer 250, which is a component of the present invention.

Referring to FIGS. 4 and 5 , a spacer 250 may be included between the plurality of rotor cores 210 to form a gap between the rotor cores 210 .

When the rotor core 210 is disposed, the spacer 250 can allow adjacent rotor cores 210 to form a certain gap. The spacer 250 may be disposed between the rotor cores 210 and help keep the spacing of the rotor cores 210 constant. The spacer 250 is formed to be smaller than the outer diameter of the rotor core 210, so that interference from the spacer 250 on the magnet 230 can be minimized.

In one embodiment, the spacer 250 may be provided in a circular ring shape and inserted into the rotation shaft 100. The circular spacer 250 having a certain thickness can stably support the gap formed by the spacer 250 when the rotor 200 rotates. Although the spacer 250 in the shape of a circular ring is shown in FIG. 5, the shape of the spacer 250 is not limited and can be modified into various shapes.

Figure 6 is an enlarged view of the internal structure of the motor 1 according to an embodiment of the present invention.

Referring to FIG. 6, the stator 300 may be disposed adjacent to the outside of the rotor 200.

In a structure in which a plurality of rotor cores 210 are coupled, the magnet 230 attached to the rotor core 210 may be provided to protrude in the axial direction of the rotation axis 100 beyond the upper and lower surfaces of the stator 300. In other words, this means that when viewed from the side of the stator 300, the magnet 230 may be arranged to protrude from the top and bottom of the stator 300.

At this time, the sum of the height (h2) of the magnet 230 protruding from the upper surface of the stator 300 and the height (h1) of the magnet 230 protruding from the lower surface of the stator 300 is the sum of the spacing between the magnets 230 (D1) It may be the same as +D2). In other words, this means that the total height (h) of the stator 300 and the height of the magnets 230 having a plurality of layered structures are equal.

Additionally, the height h2 of the magnet 230 protruding from the upper surface of the stator 300 may be arranged to be equal to the height h1 of the magnet 230 protruding from the lower surface of the stator 300.

The arrangement of the magnet 230 as described above is intended to minimize the influence of the spacing between the magnets 230 on the stator 300 by placing the magnet 230 at the center of the stator 300.

Figure 7 is a diagram showing the amount of change in cogging torque according to the gap ratio of the magnet of the present invention.

Referring to FIG. 7, it is a graph showing changes in cogging torque and back electromotive force harmonics according to changes in the spacing of the magnets 230.

Spacing ratio (gas/stator stack) 0.0% 2.0% 3.0% 4.0% 5.0% 6.0% 7.0% 8.0% cogging torque 15.8 15.0 14.6 12.6 10.2 9.7 12.36 15.0

Table 1 shows the quantitative values of the graph in FIG. 7.

It can be seen that as the ratio of the gap formed by the magnet 230 decreases, the cogging torque decreases to a certain range.

It can be seen that the cogging torque decreases gently when the gap ratio increases from 0 to 3%.

Afterwards, the cogging torque decreases rapidly in the section of 3 to 6%, and then it can be seen that the cogging torque increases again as the gap ratio increases around 6%.

Therefore, it can be confirmed that the spacing ratio of the present invention is in the range of 4 to 7% to reduce cogging torque, and preferably, having the spacing ratio in the range of 5 to 6% is more effective in reducing cogging torque. You can confirm that there is.

Above, embodiments of the present invention have been examined in detail with reference to the attached drawings.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications, changes, and substitutions can be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the attached drawings are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments and the attached drawings. . The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

1: motor
100: rotation axis
200: rotor
210: rotor core
230: Magnet
250: spacer
300: Stator
400: housing

Claims (16)

axis of rotation;
a rotor including a hole into which the rotating shaft is inserted; and
It includes a stator disposed outside the rotor,
The rotor includes a plurality of rotor cores surrounding a rotating shaft,
It includes a plurality of magnets coupled to the rotor core,
Includes a gap formed between two adjacent magnets among the plurality of magnets in the axial direction,
The sum of the intervals has a ratio of 0.04 to 0.07 of the axial length of the stator,
The magnet is provided in a curved shape that protrudes in the radial direction and is placed on the outer surface of the rotor core,
The rotor core is disposed at a certain distance from an adjacent rotor core in the axial direction of the rotation axis,
A motor wherein the sum of the spacing between the rotor cores has a ratio of 0.04 to 0.07 of the axial length of the stator. axis of rotation
a rotor including a hole into which the rotating shaft is inserted; and
It includes a stator disposed outside the rotor,
The rotor includes a plurality of rotor cores surrounding a rotating shaft,
It includes a plurality of magnets coupled to the rotor core,
The plurality of magnets include a first magnet, a second magnet, and a third magnet arranged in the axial direction,
The sum of the first gap between the first magnet and the second magnet and the second gap between the second magnet and the third magnet has a ratio of 0.04 to 0.07 of the axial length of the stator,
The plurality of magnets are provided in a curved shape that protrudes in the radial direction and are disposed on the outer surface of the rotor core,
The rotor core is disposed at a certain distance from an adjacent rotor core in the axial direction of the rotation axis,
A motor wherein the sum of the spacing between the rotor cores has a ratio of 0.04 to 0.07 of the axial length of the stator. axis of rotation;
a rotor including a hole into which the rotating shaft is inserted; and
It includes a stator disposed outside the rotor,
The rotor includes a plurality of rotor cores surrounding a rotating shaft,
It includes a plurality of magnets coupled to the rotor core,
The plurality of magnets include a first magnet, a second magnet, and a third magnet arranged in the axial direction,
It includes a spacer disposed between the first magnet and the second magnet and between the rotor core to form a gap,
The first to third magnets overlap in the axial direction and form a skew angle with each other,
The sum of the first gap between the first magnet and the second magnet and the second gap between the second magnet and the third magnet is 4% to 7% of the axial length of the stator, and the outer diameter of the spacer is Smaller than the outer diameter of the rotor core,
The plurality of magnets are provided in a curved shape that protrudes in the radial direction and are disposed on the outer surface of the rotor core,
The rotor core is disposed at a predetermined distance from an adjacent rotor core in the axial direction of the rotation shaft,
A motor wherein the sum of the spacing between the rotor cores has a ratio of 0.04 to 0.07 of the axial length of the stator. According to any one of claims 1 to 3,
a housing including the rotor and the stator;
A motor further comprising: delete According to claim 1,
A motor wherein the sum of the spacing between the rotor cores is equal to the sum of the spacing between the magnets. delete According to claim 1,
The sum of the spacing between the rotor cores is calculated as the sum of the first spacing and the second spacing formed by the plurality of rotor cores,
The first interval and the second interval are the same motor. According to claim 1,
A motor including a spacer disposed between the rotor cores to form a gap between the rotor cores. According to clause 9,
A motor in which the outer diameter of the spacer is smaller than the outer diameter of the rotor core. According to any one of claims 1 to 3,
A motor in which the distance between the plurality of magnets and adjacent magnets is the same. According to claim 1,
A motor in which a magnet protrudes in the axial direction of the rotation shaft rather than the upper and lower surfaces of the stator. According to claim 12,
A motor wherein the sum of the height of the magnet protruding from the upper surface of the stator and the height of the magnet protruding from the lower surface of the stator is equal to the sum of the spacing of the magnets. According to claim 12,
A motor in which the height of the magnet protruding from the upper surface of the stator and the height of the magnet protruding from the lower surface of the stator are the same. According to any one of claims 1 to 3,
A motor where the sum of the intervals is 0.05 to 0.06. axis of rotation;
a rotor including a hole into which the rotating shaft is inserted; and
It includes a stator disposed outside the rotor,
The rotor includes a plurality of rotor cores surrounding a rotating shaft,
It includes a plurality of magnets coupled to the rotor core,
The plurality of magnets include a first magnet and a second magnet disposed in the axial direction,
The gap between the first magnet and the second magnet is 4% to 7% of the axial length of the stator,
The plurality of magnets are provided in a curved shape that protrudes in the radial direction and are disposed on the outer surface of the rotor core,
The rotor core is disposed at a predetermined distance from an adjacent rotor core in the axial direction of the rotation shaft,
A motor wherein the sum of the spacing between the rotor cores has a ratio of 0.04 to 0.07 of the axial length of the stator.

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