KR102492064B1 - Rotor for Wound Rotor Synchronous Motor - Google Patents

Abstract

The present invention relates to a rotor for a field winding type motor, which can prevent the rotor coil from scattering during rotation of the rotor, can reduce the size of the rotor, and can reduce the manufacturing cost of the rotor. It is about. For this purpose, the rotor for a field winding type motor according to the present invention includes an inner core having a plurality of teeth formed thereon, a bobbin on which a coil is wound and inserted into the tooth part, and an outer core coupled to the tooth part into which the bobbin is inserted. characterized in that it consists of

Description

Rotor for field wound motor {Rotor for Wound Rotor Synchronous Motor}

The present invention relates to a rotor for a field winding motor, and more particularly, to prevent scattering of rotor coils during rotation of the rotor, to reduce the size of the rotor, and to reduce the manufacturing cost of the rotor. It relates to a rotor for a linear motor.

In general, a hybrid vehicle or an electric vehicle referred to as an eco-friendly vehicle is driven by an electric motor that obtains rotational force with electrical energy.

Hybrid vehicles drive in EV (Electric Vehicle) mode, which is a pure electric vehicle mode using only power from an electric motor, or in HEV (Hybrid Electric Vehicle) mode, which uses both engine and driving motor torque as power. In addition, a general electric vehicle drives by using rotational force of a driving motor as power.

Most of the drive motors used as a power source for eco-friendly vehicles use permanent magnet synchronous motors (PMSM). These permanent magnet type synchronous motors need to maximize the performance of the permanent magnets in order to achieve maximum performance under limited layout conditions.

Here, neodymium (Nd) in the permanent magnet improves the strength of the permanent magnet, and dysprosium (Dy) improves demagnetization resistance. However, these rare earth (Nd, Dy) metals of permanent magnets are limitedly deposited in some countries such as China, and are very expensive and fluctuate greatly in price.

In order to improve this, the application of an induction motor is recently being reviewed, but there are excessive limitations in size increase such as volume and weight in order to exhibit the same motor performance.

Meanwhile, in related industries, as an electric motor used as a power source for eco-friendly vehicles, development of a field winding type (WRSM) drive motor to replace a permanent magnet type synchronous motor (PMSM) is being actively pursued.

The field winding type motor can exhibit the performance of the motor with an optimal increase of about 10% compared to the permanent magnet type synchronous motor (PMSM). PMSM) is replacing permanent magnets.

In such a field winding type motor, a coil is wound around a rotor to generate magnetic flux, and a brush and a slip ring are provided outside the motor housing to generate magnetic flux, through which current is applied.

Meanwhile, FIG. 1 shows the structure of a rotor provided in a conventional field winding type motor.

As shown in FIG. 1, a conventional field wound motor rotor includes a base portion 11 having a hollow 13 into which a shaft of the rotor is inserted, and extending outward from the circumference of the base portion 11 to each other. It is configured to include a plurality of teeth parts 14 formed to be spaced apart by a predetermined interval, and a pole shoe 12 having a wider width than the teeth part 14 and provided at an end of the teeth part 14. A coil 18 to which current is applied is wound around the plurality of teeth portions 14 .

In addition, the first space portion 15 is formed between the pole shoes 12 adjacent to each other, and the second space portion 16 is formed between the adjacent tooth portions 14 in which the coil 18 is wound. there is.

However, since the conventional field winding type motor having the above configuration does not have a fixed structure for the axial direction of the rotor, there is a possibility that the coil 18 is scattered during high-speed rotation of the rotor.

That is, when the rotor rotates at a high speed, the coil 18 wound around the tooth portion 14 may be unwound and scattered to the outside through the first space portion 15 formed between the adjacent pole shoes 12 . When the coil 18 is scattered in this way, the rotational balance of the rotor is out of balance, and the insulation of the coil 18 is destroyed, resulting in a situation in which the motor cannot achieve its original performance or even becomes unusable. As a result, there is a problem in that reliability of the rotor coil structure is lowered.

In addition, in the conventional field winding type motor, in order to wind the coil 18 on the tooth part 14 of the rotor, the nozzle (not shown) of the winding machine penetrates the narrow first space 15 between the pole shoes 12, Winding work must be done. In this case, the movement space of the winding nozzle is restricted due to the spatial constraints on coil winding, which makes the coil winding work very difficult, and the coil occupancy rate (coil There was a problem that the ratio of the cross-sectional area of the conductor being made and the cross-sectional area of the entire coil) fell.

In addition, it is necessary to wind the insulating paper on the outer surface of the tooth part 14 of the rotor before winding the coil 18. There was a problem with dropping.

Republic of Korea Patent Registration No. 10-1438635 (2014.09.01)

The technical problem to be solved by the present invention is to completely block the space in which the coil can scatter when the rotor rotates, thereby providing a rotor for a field wound motor that can fundamentally prevent the coil from scattering due to the rotation of the rotor. is in

In addition, another technical problem to be solved by the present invention is to provide a rotor for a field winding type motor having a simpler shape structure and a simpler assembly structure than the rotor of an existing field winding type motor.

In addition, another technical problem to be solved by the present invention is to provide a rotor for a field winding type motor that can significantly improve the space factor compared to the existing rotor coil, and through which the overall size of the motor can be reduced. is in

In addition, another technical problem to be solved in the present invention is configured by inserting a low-cost ferrite magnet into the tooth portion of the rotor core, so that the driving efficiency can be improved using the magnetic flux of the rotor coil and the inserted magnet, through which It is an object of the present invention to provide a rotor for a field wound motor that can further reduce the size of the rotor and can be usefully used for EV/HEV and ISG (Integrated Starter Generator) motors requiring low-cost drive motors.

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

The rotor for a field winding type motor of the present invention for solving the above technical problem is an inner core having a plurality of teeth formed thereon, a bobbin in which a coil is wound and inserted into the tooth part, and a bobbin coupled to the tooth part in which the bobbin is inserted. Characterized in that it is configured to include an outer core.

The inner core may be coupled to the outer core by press fitting in an axial direction.

In addition, a coupling protrusion may be formed on one side of the tooth portion of the inner core and the outer core, and a coupling groove may be formed on the other side so that the coupling protrusion and the coupling groove are mutually engaged by axial press-fitting.

At this time, the inner core and the outer core may be configured in the form of stacking steel plates of the same material.

In addition, the outer core is formed such that a thick portion having a thick thickness and a thin portion having a small thickness are alternately arranged in a circumferential direction and connected to each other, and the tooth portion of the inner core may be configured to be engaged and coupled to the thick portion. there is.

Here, a magnetic flux leakage prevention groove may be additionally formed in the thin-walled portion to prevent magnetic flux leaking through the thin-walled portion.

At this time, the magnetic flux leakage prevention grooves may be provided in plural and arranged alternately in a zigzag shape on inner and outer portions of the thin portion.

On the other hand, the method of assembling a rotor for a field winding motor of the present invention for solving the above technical problem is to (a) winding a coil on a bobbin, (b) inserting the bobbin on which the coil is wound into an inner core and (c) coupling the outer core to the inner core into which the bobbin is inserted.

Here, in step (c), the tooth portion of the inner core may be axially press-fitted into the thick portion of the outer core to be coupled.

According to the rotor structure for a field winding type motor according to the present invention, the following useful effects can be obtained.

First, unlike the conventional rotor structure, since the space itself in which the rotor coils can be scattered is not formed, it is possible to fundamentally prevent the coils from being scattered outside the rotor during rotation of the rotor. Therefore, it is possible to completely overcome problems such as rotational balance instability of the rotor caused by scattering of the rotor coil and deterioration of motor performance due to insulation breakdown of the coil, as in the prior art, so that the reliability of the motor performance can be improved. there is.

Second, it is possible to assemble the rotor through a simple method of inserting the coil-wound bobbin into the teeth of the inner core and then coupling the outer core to the inner core, which makes it easy to assemble the rotor and reduces assembly time and cost. There are advantages to being able to

Third, the coil winding operation is performed by inserting the coil-wound bobbin into the tooth part of the inner core, so that the coil is wound by inserting a winding machine nozzle into the space between the narrow pole shoes of the rotor core as before. Since there is no coil winding, it is possible to greatly improve workability during coil winding, and it is possible to reduce the size of the motor by greatly improving the rotor coil space factor.

In addition, since the winding of the coil is performed in an external space with no spatial restrictions, the winding area of the rotor coil can be increased, thereby improving the driving force of the motor and reducing the size of the motor as needed. there is.

Fourth, as the low-cost ferrite magnet is additionally inserted into the inner core teeth of the rotor, the magnetic flux generated from the ferrite magnet and the magnetic flux generated from the rotor coil act simultaneously, so that the driving force of the rotor can be further improved.

Fifth, as the driving force of the rotor can be improved as described above, it is possible to obtain the desired performance of the motor without making the size of the rotor larger than necessary. It has the advantage of being useful for EV/HEV and ISG (Integrated Starter Generator) motors.

Sixth, by forming a magnetic flux leakage prevention groove in the thin part of the outer core having a thin thickness, magnetic flux leaking through the thin part can be minimized, so there is an effect of preventing other torque reduction phenomena in the leakage magnetic flux. .

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a view showing the structure of a rotor for a conventional field winding type motor.
2 is a perspective view showing the structure of a rotor for a field winding type motor according to an embodiment of the present invention.
Figure 3 is an exploded perspective view of Figure 2;
4 is a detailed view showing a state in which the inner core and the outer core of the rotor are coupled by protrusions and grooves;
5 is a comparison diagram showing a comparison between a pole arc value of a conventional rotor and a pole arc value of a rotor according to the present invention.
6 is an assembly view showing how a coil is assembled to a bobbin;
7 is an assembly view showing a state in which an outer core is assembled after inserting a bobbin in which a coil is wound on an inner core;
8 is a conceptual diagram conceptually illustrating a phenomenon in which leakage magnetic flux is generated through a thin portion of an outer core during rotation of a rotor.
9 is a detailed view showing a structure in which magnetic flux leakage prevention grooves are formed in a thin portion of an outer core as another embodiment of the present invention.

Hereinafter, a preferred embodiment of a rotor of a field winding type motor according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a perspective view showing the structure of a rotor for a field winding type motor according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of FIG. 2 . And, FIG. 4 is a detailed view showing a state in which the inner core and the outer core of the rotor are coupled by protrusions and grooves.

2 to 4, the rotor 100 for a field winding type motor according to an embodiment of the present invention includes an inner core 110 having a plurality of tooth portions 111 formed thereon, and a coil 140 is wound. and includes a bobbin 130 inserted into the tooth portion 111 and an outer core 120 coupled to the tooth portion 111 into which the bobbin 130 is inserted.

One characteristic structure of the rotor 100 for a field winding type motor according to the present invention is that the rotor core has two separate structures of an inner core 110 and an outer core 120, unlike conventional rotors.

Here, the inner core 110 is formed by stacking a plurality of thin silicon steel plates, and a hollow 112 into which a shaft (not shown) of the rotor 100 is inserted is formed in the center, and around the hollow 112 A plurality of tooth portions 111 are formed in a radially outward direction.

At this time, the plurality of tooth portions 111 have a rectangular parallelepiped shape and are arranged at equal intervals from each other and spaced apart from each other by a predetermined distance.

Another characteristic structure of the rotor 100 according to the present invention is that the externally wound coil 140 is inserted into the tooth portion 111 of the inner core 110, unlike the conventional rotor structure.

That is, the bobbin 130 on which the coil 140 is wound is inserted into the tooth portion 111 of the inner core 110 to form the coil 140 around the tooth portion 111 .

The bobbin (Bobbin; 130) is formed to have a square tube shape corresponding to the shape of the tooth portion 111.

That is, the bobbin 130 has a structure in which both surfaces facing each other are open so that it can be inserted into the tooth portion 111.

At this time, in order to prevent the bobbin 130 on which the coil 140 is wound from easily falling out while being inserted into the tooth portion 111, a tolerance is applied so that a certain level of frictional force is applied between the tooth portion 111 and the bobbin 130 It is desirable to have a design.

Since the coil 140 is wound around the bobbin 130 having a square shape, the shape of the coil 140 completely wound around the bobbin 130 also forms a square shape.

The coil 140 generates magnetic flux around the tooth portion 111 when current is applied through a brush and a slip ring installed outside the rotor 100 .

Here, although not shown in the drawing, it is possible to contribute to torque improvement by installing a separate permanent magnet for generating additional magnetic flux to each tooth part 111 of the inner core 110 to increase the magnetic flux.

At this time, as the permanent magnet, a relatively inexpensive low-cost ferrite permanent magnet may be employed instead of the rare earth permanent magnet commonly applied to high-performance motors, and each tooth of the inner core 110 may be used as the permanent magnet. For each part 111, a pair may be installed in parallel.

5 is a comparison between the pole arc value of the conventional rotor and the pole arc value of the rotor according to the present invention, and in the conventional rotor structure shown in FIG. Since the pole shoes 12 form a spaced structure apart from each other, the pole arc value is as small as 35.029°. In contrast, since the rotor of the present invention has a structure in which adjacent pole shoe parts are connected to each other through the thin part 123 as shown in FIG. 5 (b), the pole arc due to the formation of the additional thin part 123 The value can be formed much larger than the existing rotor by about 45°.

Such a pole arc value is one of the important factors contributing to the improvement of motor torque and the reduction of torque ripple. When the pole arc value increases, the harmonic component of magnetic flux density, which is a sine wave, is reduced, reducing torque ripple. However, in the case of the existing rotor structure as shown in (a) of FIG. 5, since the space portion 15 must be provided to secure a space into which a winding machine nozzle for coil winding can be inserted, the pole arc value This was bound to be limited, and in relation to winding the coil by inserting the nozzle of the winding machine through the narrow space portion 15, the number of winding turns wound on each tooth portion 14 is limited, so that the area ratio is limited. Although there was a limitation in the phase, in the rotor structure of the present invention, the torque ripple can be greatly reduced due to the increase in the pole arc value due to the addition of the thin portion 123 of the outer core 120, and the outer core 120 can be replaced with the inner core ( 110), since the coil is wound around the tooth portion 111 of the inner core 110 in a free state without spatial restrictions, it can contribute to improving the space factor of the coil compared to the existing rotor.

Meanwhile, the outer core 120 is made of the same material as the inner core 110, and like the inner core 110, a plurality of thin silicon steel plates are stacked.

In addition, the outer core 120 has a structure in which a thick portion 121 having a thick thickness and a thin portion 123 having a thin thickness are alternately disposed along the circumferential direction of the outer core 120 .

At this time, the thin portion 123 is a thin portion forming the original thickness of the outer core 120, and the thick portion 121 protrudes inward from the inner surface of the outer core 120 by a predetermined width. are forming

Therefore, when the inner core 110 is coupled to the outer core 120, the tooth portion 111 of the inner core 110 is positioned at the thick portion 121 of the outer core 120, and the axis It is pushed in the direction and press-fitted into the outer core 120 to be coupled.

In this case, the inner surface of the thick portion 121 of the outer core 120 is formed in a flat planar state, so that the end surface of the tooth portion 111 of the inner core 110 adheres to the flat surface of the thick portion 121 and is coupled It can be.

At this time, the inner surface of the thick portion 121 of the outer core 120, to which the tooth portion 111 of the inner core 110 is closely coupled, is provided with a coupling protrusion 124 protruding in a certain width toward the center. The coupling protrusion 124 is formed in a structure elongated in parallel with the axial direction of the outer core 120 .

In addition, a coupling groove 114 recessed to have a shape corresponding to the outer shape of the coupling protrusion 124 is formed on the end surface of the tooth portion 111 of the inner core 110, so that the inner core 110 and the outer core When the 120 is coupled, the coupling protrusion 124 is press-fitted into the coupling groove 114 in the axial direction, and is formed to engage with each other in a concavo-convex structure.

In addition, end plates, which are disc-shaped cover members, are coupled to the flat side surfaces of the inner core 110 and the outer core 120 coupled in the same manner as described above.

At this time, a plurality of heat dissipation units (not shown) for heat dissipation and a rotor fan (not shown) for improving heat dissipation performance by the heat dissipation unit may be provided on the surface of the end plate (not shown).

Hereinafter, a method of assembling a rotor for a field winding type motor of the present invention having the above configuration will be described.

6 is an assembly view showing how the coil 140 is assembled to the bobbin 130, and FIG. 7 is the bobbin 130 on which the coil 140 is wound through the assembly process of FIG. 6 is attached to the inner core 110. It is an assembly view showing how to assemble the outer core 120 after being inserted.

6 and 7, the assembly of the field winding type motor rotor 100 according to the present invention,

First, as shown in FIG. 6 , a coil assembly in which the coil 140 and the bobbin 130 are integrated is prepared by winding the coil 140 around the bobbin 130 multiple times.

In this case, the coil 140 wound on the bobbin 130 is wound with a sufficient number of windings to exhibit the optimum performance of the motor.

Then, as shown in FIG. 7 , the bobbin 130 on which the coil 140 is wound is sequentially pressed into and coupled to each tooth portion 111 of the inner core 110 .

When the insertion of the coil 140 into each tooth portion 111 of the inner core 110 is completed as described above, finally, the tooth portion 111 of the inner core 110 is inserted into the thick portion 121 of the outer core 120. ) part, the assembly of the rotor 100 is completed by press-fitting and combining the inner core 110 into the outer core 120 in the axial direction. Alternatively, on the contrary, the outer core 120 may be coupled by press-fitting the inner core 110 in the axial direction.

At this time, the mutual coupling of the inner core 110 and the outer core 120 is such that the coupling protrusion 124 of the outer core 120 is press-fitted into the coupling groove 114 of the inner core 110 in the axial direction to engage with each other. By doing so, the combination can be made easily.

Here, in the above embodiment, the bobbin 130 on which the coil 140 is wound is sequentially press-fitted into each tooth portion 111 of the inner core 110 to couple the coil 140 to each tooth portion 111 However, unlike this, the bobbin 130, on which the coil 140 is not wound, is first inserted into each tooth part 111, and then the coil 140 is wound around the bobbin 130, and then the outer core 120 Alternatively, the outer core 120 may be coupled after winding the coil 140 around each tooth portion 111 without using the bobbin 130 .

On the other hand, FIG. 8 conceptually illustrates a phenomenon in which leakage magnetic flux is generated through the thin-walled portion of the outer core when the rotor rotates, and the magnetic flux generated from the N pole of the rotor 100 when the motor operates is It passes through the stator 200 located outside of and returns to the adjacent S-pole portion to form a closed loop as shown in the solid line portion of FIG.

At this time, in the rotor structure according to the present invention described above, since the neighboring pole shoe parts (thick part part) form a structure connected to each other through the thin part 123, the form indicated by the dotted line through the thin part 123 and A certain amount of leakage flux (LF) may be generated in the same direction. Since the leakage flux generated in this way may reduce the torque of the motor, it may be necessary to improve this.

9 shows a rotor structure according to another embodiment of the present invention, in order to maximally suppress magnetic flux leaking through the thin portion 123 of the outer core 120 as described above, the thin portion of the outer core 120 A separate magnetic flux leakage prevention groove 125 as shown in FIG. 9 may be formed at the portion 123.

That is, rectangular magnetic flux leakage prevention grooves 125 are formed in the inner and outer directions of the thin portion 123 of the outer core 120, respectively, and these magnetic flux leakage prevention grooves 125 are formed in the thin portion 123. It may be formed to be alternately arranged in a zigzag shape along the longitudinal direction. According to the arrangement structure of the magnetic flux leakage prevention grooves 125, leakage magnetic flux passing through the thin portion 123 of the outer core 120 during operation of the motor is formed by the plurality of magnetic flux leakage prevention grooves 125. Since the smooth movement is limited by the complicated passage structure in the 123, the generation of leakage flux through the thin portion 123 can be minimized, thereby preventing the torque of the motor from being reduced.

At this time, the shape, number, and arrangement of the magnetic flux leakage prevention grooves 125 are not limited to the structure of the above-described embodiment, and may be changed and applied to various shapes, numbers, and arrangement according to the design specifications of the motor. In addition, the thickness (t) of the thin portion 123 on which the magnetic flux leakage prevention groove 125 is formed is formed to have an appropriate thickness (t) in consideration of strength supplementation such as member cracking/fracture caused by the centrifugal force of the rotor. desirable.

As described above, in the rotor 100 for a field winding type motor according to the present invention, the space in which the rotor coil 140 can be scattered is fundamentally blocked by the structure of the outer core 120 having a ring shape. , When the rotor 100 rotates, it is possible to fundamentally prevent the coil 140 from scattering to the outside of the rotor. Therefore, it is possible to completely overcome problems such as rotational balance instability of the rotor frequently caused by scattering of the rotor coil and deterioration in performance of the motor due to insulation breakdown of the coil, and to improve the reliability of the motor performance. can

In addition, the rotor is assembled through a simple assembly method in which the bobbin 130 on which the coil 140 is wound is inserted into the tooth portion 111 of the inner core 110 and then the outer core 120 is coupled to the inner core 110 Since this is completed, it is possible to improve the assembly performance according to the assembly of the rotor, and it is possible to greatly reduce the time and cost required for assembly of the rotor.

In addition, since the winding operation of the coil 140 to the tooth portion 111 is completed by a simple method of inserting the bobbin 130 on which the coil 140 is wound into the tooth portion 111 of the inner core 110, There are advantages in that workability according to coil winding can be greatly improved and the overall size of the motor can be reduced by greatly improving the rotor coil space factor.

In addition, since the winding work of the coil 140 is performed in the outer space of the rotor without any spatial restrictions, the winding area of the rotor coil 140 can be increased, thereby improving the driving force of the motor.

In addition, as low-cost ferrite permanent magnets are additionally inserted into the inner core tooth portion 111 of the rotor, the driving force of the rotor can be greatly improved through the magnetic flux generated from the ferrite permanent magnet and the magnetic flux generated from the rotor coil 140. There are advantages to being In addition, by improving the driving force of the rotor as described above, it is possible to obtain sufficient performance of the desired motor without having to make the size of the rotor larger than necessary, so that ultimately miniaturization of the motor is possible, and It has the advantage of being useful for EV/HEV and ISG (Integrated Starter Generator) motors.

The embodiments described in this specification and the accompanying drawings merely illustrate some of the technical ideas included in the present invention by way of example. Therefore, since the embodiments disclosed in this specification are intended to explain rather than limit the technical spirit of the present invention, it is obvious that the scope of the technical spirit of the present invention is not limited by these embodiments. All modified examples and specific examples that can be easily inferred by those skilled in the art within the scope of the technical idea included in the specification and drawings of the present invention should be construed as being included in the scope of the present invention.

100: rotor 110: inner core
111: tooth part 112: hollow
114: coupling groove 120: outer core
121: thick part 123: thin part
124: coupling protrusion 125: magnetic flux leakage prevention groove
130: bobbin 140: coil

Claims (9)

an inner core 110 having a plurality of teeth portions 111;
a bobbin 130 on which the coil 140 is wound and inserted into the tooth portion 111; and
an outer core 120 coupled to the tooth portion 111 into which the bobbin 130 is inserted;
including,
In the outer core 120, a thick portion 121 having a thick thickness and a thin portion 123 having a small thickness are alternately arranged in a circumferential direction and connected to each other,
The tooth portion 111 of the inner core 110 is engaged and coupled to the thick portion 121,
A plurality of magnetic flux leakage prevention grooves 125 are formed in the thin portion 123 to prevent magnetic flux leaking through the thin portion 123,
The plurality of magnetic flux leakage prevention grooves 125 are alternately disposed on the inside and outside of the thin portion 123. The rotor for a field winding type motor.
The rotor for a field winding type motor according to claim 1, wherein the inner core (110) is press-fitted and coupled to the outer core (120) in an axial direction.
The method of claim 2, wherein a coupling protrusion 124 is formed on one side of the tooth portion 111 of the inner core 110 and the outer core 120, and a coupling groove 114 is formed on the other side,
The coupling protrusion 124 and the coupling groove 114 are mutually engaged and coupled by axial press-fitting, characterized in that the field winding type motor rotor.
The rotor for a field winding type motor according to claim 1, wherein the inner core (110) and the outer core (120) are formed by stacking steel plates of the same material.
delete delete [Claim 2] The rotor for a field winding type motor according to claim 1, wherein the magnetic flux leakage prevention grooves (125) are provided in plural and alternately arranged in a zigzag shape on the inside and outside of the thin portion (123). delete delete

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