KR20190121740A - A Ring Magnet Applied Type of a Rotor of a Motor for a Robot with a Eccentric Type of a Structure Having a Lower Cogging and a Lower Torque Ripple - Google Patents

Abstract

The present invention relates to a robot motor rotor with eccentric ring magnets for low cogging and low torque ripple and, more specifically, to a robot motor rotor with eccentric ring magnets for low cogging and low torque ripple, which is applied to a brushless direct motor (BLDC) for robot joints. The robot motor rotor with eccentric ring magnets for low cogging and low torque ripple comprises: an annular strip-shaped rotor core (11) having the constant height; and ring-shaped first and second magnetic pole unit groups coupled to a circumferential surface of the rotor core (11) and having different magnetic pole units (12_1 to 12_N and 13_1 to 13_N) continuously arranged therein. At least a portion of each of the magnetic pole units (12_1 to 12_N and 13_1 to 13_N) of the first and second magnetic pole unit groups is integrated. The present invention can reduce manufacturing costs of a motor.

Description

A ring magnet applied type of a rotor of a motor for a robot with a eccentric type of a structure having a lower cogging and a lower torque ripple }

The present invention relates to a motor rotor for a robot having an eccentric ring magnet application structure for low cogging and low torque ripple, and specifically for low cogging and low torque ripple applied to a brushless direct motor (BLDC) motor for jointing of a robot. It relates to a motor motor rotor for an eccentric ring magnet application structure.

Various parts of the joints of the robot may be operated by a motor, and a brushless direct motor (BLDC), which has an advantage in terms of noise or durability, may be used although a direct current motor or a similar motor may be used. The BLDC motor is formed of a rotor made of a permanent magnet or a stator pole which is disposed around the rotor and the rotor to form a winding-shaped electromagnet, and mechanical energy is generated while the rotor rotates inside the winding by supply of current. The BLDC motor having such a structure has a high efficiency, a small noise, and a long life and has the advantage of being able to be made compact, and thus has been applied to various machines having weight or space constraints.

Patent registration No. 10-1301261 discloses a hollow BLDC motor for implementing a hollow joint that can be used in the robot joint constituting the manipulator. In addition, Korean Patent Publication No. 10-2013-0090126 discloses a BLDC motor driving device that does not require expensive Hall sensors and complicated sensor circuits by directly measuring the position of a rotating rotor by installing one sensing coil inside the BLDC motor. It is started.

In order to apply the BLDC motor for the operation of the joints or similar parts of the robot, it is necessary to reduce the torque ripple while simultaneously reducing the cogging caused by the counter electromotive force. However, the prior art does not disclose a motor structure that has such operating characteristics.

The present invention is to solve the problems of the prior art has the following object.

Prior Art 1: Patent Registration No. 10-1301261 (Sunchon National University Industry-Academic Cooperation Foundation, September 10, 2013 announcement) Hollow type motor and robot joint structure using the same Prior Art 2: Patent Publication No. 10-2013-0090126 (Korea Electronics and Telecommunications Research Institute, published on August 13, 2013)

It is an object of the present invention for a robot having an eccentric ring magnet application structure for a low cogging and low torque ripple applicable to a robot motor by being disposed in a circular co-stimulation unit and driven by a low cogging and low torque ripple structure of a BLDC motor. It is to provide a motor rotor and a BLDC motor having the same.

According to a preferred embodiment of the present invention, a robot motor rotor having an eccentric ring magnet application structure for low cogging and low torque ripple includes an annular band-shaped rotor core having a constant height; And ring-shaped one or two magnetic pole unit groups coupled to the circumferential surface of the rotor core and in which different magnetic pole units are continuously disposed, wherein at least a portion of each magnetic pole unit of the one or two magnetic pole unit groups is integrated. .

According to another suitable embodiment of the invention, each of the different magnetic pole units has a different thickness in both directions relative to the center portion along the circumferential direction.

According to another suitable embodiment of the present invention, a brushless direct current (BLDC) motor, comprising: a ring-shaped motor rotor in which a plurality of different magnetic pole units are continuously disposed along a circumferential direction; A stator disposed on a circumferential surface of the motor rotor and comprising a plurality of windings separated from each other corresponding to different magnetic pole units; And an insulating unit coupled to the stator such that each winding is separated from each other, wherein at least a portion of the plurality of windings is fixed to one band-shaped fixing frame.

According to another suitable embodiment of the present invention, the motor rotor consists of a rotor core and a group of magnetic pole units to which the rotor core is coupled.

In the motor rotor according to the present invention, a plurality of magnetic pole units are continuously disposed in a drum shape, and thus, cogging levels may be lowered, and at the same time, torque ripple with respect to an applied current may be reduced. This structure makes it possible to manufacture a high-efficiency BLDC motor at a small size while reducing the manufacturing cost of the motor. The motor according to the present invention can be manufactured at a very low cost, and can be applied to a very low cost small and medium manufacturing robot by being made lightweight and compact and having high power density characteristics.

1A and 1B illustrate an embodiment of a robot motor rotor having an eccentric ring magnet application structure for low cogging and low torque ripple according to the present invention.
2A and 2B illustrate an embodiment of a BLDC motor to which a motor rotor according to the present invention is applied.
3 illustrates an embodiment of a drive module to which a motor according to the present invention is applied.
Figure 4 illustrates an embodiment of an articulated robot applied to the manufacturing process to which the motor according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the embodiments set forth in the accompanying drawings, but the embodiments are provided for clarity of understanding and the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have similar functions, and thus are not repeatedly described unless necessary for understanding of the invention, and well-known components are briefly described or omitted. It should not be understood to be excluded from the embodiment of.

1A and 1B illustrate an embodiment of a robot motor rotor having an eccentric ring magnet application structure for low cogging and low torque ripple according to the present invention.

Referring to Figure 1a, the robot motor rotor 10 of the ring magnet application structure of the eccentric method for low cogging and low torque ripple has an annular band-shaped rotor core 11 having a constant height; And a ring-shaped group of one or two magnetic pole units coupled to the circumferential surface of the rotor core 11 and in which different magnetic pole units 12_1 to 12_N and 13_1 to 13_N are disposed in succession. At least a portion of each of the stimulation units 12_1 to 12_N and 13_1 to 13_N of is integral.

The motor may be a brushless direct current (BLDC) and may be applied to drive control of the robot. The motor rotor 10 may be a rotor of the motor, may be disposed in the center portion to be hollow, and may be connected to the reducer. The stator may be disposed on the circumferential surface of the motor rotor 10, and when the current is applied to the windings disposed on the stator, the motor rotor 10 may be rotated. In addition, the Hall sensor may be disposed to detect the position of the motor rotor 10. The motor rotor 10 may be formed of the rotor core 11 and the magnetic pole unit group.

The rotor core 11 may be in the form of an annular band having a constant height, for example in the shape of a ring. The rotor core 11 may be made of aluminum, alumina, brass, stainless steel, or an alloy thereof, which is not magnetic, or may be made of an inorganic material such as rigid synthetic resin or silicon, but is not limited thereto. It can be made of various materials with. The rotor core 11 may have a ring shape or a strip shape having a constant height along the circumferential surface. In addition, the rotor core 11 may have a hollow shape having a uniform thickness along the circumferential surface, and a stretchable coating layer may be formed on the outer circumferential surface. For example, the flexible coating layer may be silicone, polyurethane or similar synthetic resin material.

The stimulus unit group may include a plurality of different stimulus units, for example, one stimulus unit group consisting of a plurality of N poles 12_1 to 12_N and a two stimulus unit group consisting of a plurality of S poles 13_1 to 13_N. Can be made. The different stimulation units 12_1 to 12_N and 13_1 to 13_N may be alternately arranged in succession or successively so that the N pole and the S pole are repeated. For example 10 to 30 stimuli, preferably 15 to 25 stimuli, most preferably 20 stimuli can be arranged in succession.

According to one embodiment of the present invention, at least a portion of each of the stimulation units 12_1 to 12_N and 13_1 to 13_N may be integrated, and preferably, one or two groups of stimulation units may be made integral. Integral type refers to being made of a single structure, for example, is formed in succession so that different magnetic poles adjacent to the ring-shaped magnetic body of 20 magnetic poles. Magnetic materials include aluminum-nickel-cobalt; Barium-ferrite; Strontium-ferrite; Rare earths; It can be made of chromium or similar material, and alternating continuous magnetic pole units can be made by sintering or casting. Specifically, the magnetic material may be made of a base ring to have a diameter that can be coupled to the outer surface of the rotor core 11. In addition, one magnetic pole unit 12_1 to 12_N and two magnetic pole units 13_1 to 13_N may be alternately formed in a multipolar magnetization manner along the circumferential surface of the base ring. Multipolar magnetization may be achieved in such a way that a plurality of magnetized coils wound in different directions are disposed around the base ring and a current is applied to each magnetized coil. The ring base may be a single structure or a structure in which a plurality of sub ring bases are connected to each other. The multipolar magnetized ring base can form one or two magnetic pole unit groups and can be assembled in an assembly manner to the outer circumferential surface of the rotor core 11. Alternatively, after the ring base is coupled to the rotor core 11 in an assembled manner, the predetermined area may be magnetized to have a predetermined magnetic pole. Thus, the work of the motor rotor 10 by continuously forming a plurality of magnetic poles on one ring base or a plurality of sub ring bases, and by coupling the ring base on which a plurality of magnetic poles are formed to the circumferential surface of the rotor core 11. Make the process simple. Each of the magnetic pole units 12_1 to 13_N may have the same or similar structure, and may have, for example, a saddle shape having an inner surface and an outer surface having a thickness. In addition, the different magnetic pole units 12_1 to 13_N are alternately disposed adjacent to each other to form a group of one and two magnetic pole units having a ring-shaped magnet structure surrounding the outer circumferential surface of the rotor core 11. 10) can be made. An elastic coating layer may be formed between the 1 and 2 magnetic pole unit groups and the rotor core 11, and the elastic coating layer may have an adhesive function. For example, a flexible coating layer of a synthetic resin material may be formed on the outer circumferential surface of the rotor core 11 uniformly to a thickness of, for example, 10 to 100 μm. In addition, the rotor core 11 may be coupled to the magnetized or non-magnetized base ring in an interference fit manner. After the ultrasonic wave or heat is applied, the base ring and the rotor core 11 may be firmly coupled by the elastic coating layer to be made of the motor rotor 10. The stretchable coating layer may be made of a thermosetting resin or similar thermally resistant material, which prevents deformation of the motor rotor 10 during operation of the motor. Alternatively, an anti-rotation structure can be made on the outer circumferential face of the rotor core 11 and the inner circumferential face of the ring base. For example, the anti-rotation structure may be made of a combination structure of grooves and protrusions, but is not limited thereto and may be made of various structures in which relative rotation may be prevented.

Cogging and torque ripple can be reduced by disposing different magnetic pole units 12_1 to 13_N along the circumferential surface of the ring base. Additionally cogging and torque ripple can be reduced by adjusting the magnetic field of each magnetic pole unit 12_1 to 13_N. Specifically, caulking or torque ripple may be reduced by having a structure in which the thickness of each of the magnetic pole units 12_1 to 13_N is made smaller on both sides of the middle portion. Such stimulation units 12_1 to 13_N may have an eccentric structure.

It is described in detail below.

Referring to FIG. 1B, each of the different stimulation units 12_1 to 12_N and 13_1 to 13_N may have different thicknesses in both directions with respect to the center portion along the circumferential direction.

The base ring for forming the 1, 2 magnetic pole unit groups may be composed of a fixed base member and a magnetic pole forming unit, and the fixed base member may have a ring shape having a relatively thin thickness and having a constant height. In addition, magnetic pole forming units 12_1 to 13_N may be formed by magnetization. In detail, the inner surface of the magnetic pole forming unit may have a shape corresponding to the outer circumferential surface of the fixed base member, and the outer surface of the magnetic pole forming unit has a symmetrical structure in which the thickness becomes thinner with respect to the middle portion along the circumferential direction. Can be. And the outer surface as a whole may be curved, and the magnetic pole forming units adjacent to each other may be connected in a structure in which the edge faces facing each other. As a result, different magnetic pole units 12_1 to 13_K may be continuously disposed on the outer circumferential surface of the rotor core 11.

The stationary base member and the pole forming unit may be made in one piece through a forging process, a pressing process, a cutting process, or a similar process. In addition, the thus formed groups of 1 and 2 magnetic pole units may be coupled to the rotor core 11 in the same or similar manner as described in FIG. 1A.

The stimulus units 12_1 to 13_N of the eccentric structure can be made in various ways and are not limited to the embodiments shown.

Hereinafter, a BLDC motor to which a motor rotor according to the present invention is applied will be described.

2A and 2B illustrate an embodiment of a BLDC motor to which a motor rotor according to the present invention is applied.

2A and 2B, a BLDC motor includes a ring-shaped motor rotor 10 in which a plurality of different magnetic pole units are continuously disposed along a circumferential direction; A stator 21 disposed on a circumferential surface of the motor rotor 10 and composed of a plurality of windings 211 separated from each other corresponding to different magnetic pole units; And an insulating unit 23 coupled to the stator 21 so that each of the windings 211 is separated from each other, and at least a portion of the plurality of windings 211 is fixed to one band-shaped fixing frame 212. .

The motor may be applied to an assembly robot for automation of a manufacturing process, but is not limited thereto and may be applied to a joint or other part of a robot having various uses. The motor according to the present invention can be a hollow structure having more than 20 multi-pole structure while allowing a lightweight, high power density and thin film structure of the robot.

The motor rotor 10 may have the same or similar structure as the motor rotor shown in FIGS. 1A and 1B, and may have a hollow ring shape. The motor rotor 10 may be disposed in the stator 21 of the hollow drum shape. The stator 21 may include a winding magnetic pole formed at a position corresponding to a portion where the magnetic pole of the motor rotor 10 is formed, and different winding magnetic poles may be made in the same or similar shape. And the insulating unit 23 is coupled to one portion of the stator 21 so that each of the winding magnetic poles are separated from each other to maintain the insulating state.

2B illustrates the assembly diagram of FIG. 2A, in which the motor rotor 10, the stator 21, and the insulation unit 23 may be disposed inside the motor casing 24. The motor casing 24 may have a suitable internal structure in which the stator 21 and the motor rotor 10 may be fixed, and for example, a speed reducer may be connected to the motor rotor 10. 2B, the windings 211 having the same or similar shape may be coupled to and fixed to the fixing frame 212 having the band shape. In the manufacturing process of the stator 21, the fixing frame 212 may be made of a linear band shape, it may be made of a stretchable insulating material. The fixed frame 212 has a plurality of winding cores formed at regular intervals on an inner side thereof, and the winding cores may have a hexahedron or cylinder shape. In addition, the fixing frame 212 and the fixing pieces 213a and 213b at one end of the winding core may be coupled to each other, and the fixing pieces 213a and 213b may be made into a structure that can be coupled to an insertion hole formed in the insulation unit 23. have. The winding core may for example be 20 or more and may be a winding in a linear arrangement. The fixing frame 212, the winding core and the fixing pieces 213a and 213b may be integrally formed, and the fixing frame 212 may be made in various shapes to join different winding cores.

A plurality of winding cores may be wound simultaneously, and a plurality of winding cores that have been wound may be made in a ring shape, and the insulation unit 23 may be coupled to fix each winding magnetic pole in a predetermined position. For example, the winding magnetic poles may be separated from each other and fixed by being coupled to the insertion hole formed in the annular band-shaped insulating unit 23 by the square plate-shaped two fixing pieces 213b formed at the free end of the winding core. . And the BLDC motor can be made by the motor rotor 10 is disposed inside the stator 21, the stator 21 is fixed to the inside of the motor casing (24). A plurality of Hall sensors can be placed in the stator 21 or other suitable position to detect the position of the motor rotor 10 and the motor can be coupled with actuation control means such as for example a speed reducer.

3 illustrates an embodiment of a drive module to which a motor according to the present invention is applied.

Referring to FIG. 3, the drive module may include a speed reduction unit disposed inside the drive housing 31; A motor 20 connected to the deceleration unit; Brake 32; An encoder 33 for detecting an operating state of the motor 20; And a position detection unit 34 connected to the hall sensor to detect a position of the rotor. The drive housing 31 may have a cylindrical shape in which an accommodation space is formed, and a connection unit connected to another part of the robot may be coupled to one part. The connection unit may be connected to the reducer disposed inside the drive housing 31, and the reducer may be connected to the hollow shaft of the motor 20. The operation of the motor 20 may be limited by the brake 32, and a processor for processing an operation signal may be disposed inside the encoder 33 as necessary. In addition, the position detection unit 34 may include a driver for driving the motor 20. The encoder 33 and the position detection unit 34 may be made in the form of a circular substrate and may be coupled to one side of the drive housing 31 to control the operation of the motor 20 disposed inside the drive housing 31. This structure allows the drive module to be made compact and manufactured at low cost. In addition, the driving module thus made may be disposed at joints of various positions of the robot without changing hardware.

Figure 4 illustrates an embodiment of an articulated robot applied to the manufacturing process to which the motor according to the present invention.

Referring to FIG. 4, the driving module 42 may control the operation of the assembly robot by connecting different operation members 41 of the assembly robot. The different joints of the actuation member 41 may be formed of drive modules 42 having the same or similar physical structure and may be adjusted by the control platform 45 of the operation of each drive module 42. The control platform 45 may be connected to the drive setting panel 44, and the operation according to the operation of the control platform 45 may be displayed on the monitoring unit 43. As described above, the driving module manufactured by the motor according to the present invention is applied to various types of robot joints to facilitate design and manipulation.

In the motor rotor according to the present invention, a plurality of magnetic pole units are continuously disposed in a drum shape, and thus, cogging levels may be lowered, and at the same time, torque ripple with respect to an applied current may be reduced. This structure makes it possible to manufacture a high-efficiency BLDC motor at a small size while reducing the manufacturing cost of the motor. The motor according to the present invention can be manufactured at a very low cost, and can be applied to a very low cost small and medium manufacturing robot by being made lightweight and compact and having high power density characteristics.

Although the present invention has been described in detail above with reference to the presented embodiments, those skilled in the art may make various modifications and modifications without departing from the technical spirit of the present invention with reference to the presented embodiments. . The invention is not limited by the invention as such variations and modifications but only by the claims appended hereto.

10: motor rotor 11: rotor core
12_1 to 12_N and 13_1 to 13_N: stimulus unit
20: motor 21: stator
23: insulation unit 24: motor casing
31: drive housing 32: brake
33: encoder 34: position detection unit
41: operating member 42: drive module
43: monitoring unit 44: drive setting panel
45: control platform 211: winding
212: fixed frame 213a, 213b: 1, 2 fixed piece

Claims (1)

In brushless direct current (BLDC) motors,
The rotor core 11, the first and second magnetic pole unit groups and the rotor coater in which a plurality of N poles 12_1 to 12_N and a plurality of S poles 13_1 to 13_N formed on the circumferential surface of the rotor core 11 are disposed in succession. A motor rotor 10 composed of an elastic coating layer formed between the 11 and the first and second magnetic pole unit groups;
A stator 21 disposed on a circumferential surface of the motor rotor 10 and composed of a plurality of windings 211 separated from each other corresponding to different magnetic pole units; And
It includes an annular band-shaped insulating unit 23 is coupled to one portion of the stator 21 so that each winding 211 is separated from each other,
At least a part of the plurality of windings 211 is fixed to one band-shaped fixing frame 212,
The fixing frame 212 and the fixing pieces 213a and 213b are coupled to one end of the winding core, and the square plate-shaped fixing piece 213b formed at the free end of the plurality of winding cores is an annular band-shaped insulating unit 23. BLDC motor, characterized in that coupled to the insertion hole formed in the winding magnetic poles are separated from each other and fixed.

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