Patent Description:
The present invention relates generally to a thin-plate module horseshoe-type PMG (permanent magnet) rotor for a motor, and more particularly to a thin-plate module horseshoe-type PMG rotor for a motor, according to claim <NUM>, in which a core is divided into an iron core and a pole plate core without being molded and magnets are assembled therebetween.

Generally, a motor is an actuator that receives electrical energy and converts it into mechanical energy. Such a motor consists of a stator configured to receive electricity and a rotor configured to generate a magnetic field. When current is supplied, Lorentz force is generated in a direction perpendicular to magnetic force, and thus the rotor is rotated.

The rotor of a general motor is now described with reference to <FIG>. A rotating shaft <NUM> is installed at the center of the rotor <NUM>, the outer circumferential surface of the rotating shaft <NUM> is surrounded by a rotor core <NUM>, and magnets <NUM> configured to generate magnetic force to drive the rotor <NUM> are coupled to the outer circumferential surface of the rotor core <NUM>.

Since the magnets <NUM> may be separated by centrifugal force when the rotor <NUM> is rotated, insert molding is performed on the outside of the magnets <NUM> in order to prevent the separation.

By the insert molding, a mold <NUM> is filled through a circular mold, the mold <NUM> is hardened over time, and the rotor <NUM> is formed in a form surrounding the magnets <NUM>.

However, as shown in <FIG>, in the process of performing insert molding on the rotor <NUM>, the thickness of the mold <NUM> outside the magnets <NUM> and the thickness of the mold <NUM> between the magnets <NUM> are different, and thus the hardening speeds thereof are different from each other, with the result that deformation occurs in the thicker side of the mold <NUM>.

In other words, there occurs a phenomenon in which the mold <NUM> in the portion of the rotor <NUM> between the magnets <NUM> is recessed.

As shown in the drawing, irregularities <NUM> are generated on the outer circumferential surface of the mold <NUM>.

Therefore, as described above, due to the deformation of the mold <NUM>, the quality of products deteriorates and product defects occur.

Furthermore, as described above, the irregularities <NUM> generated on the outer circumferential surface of the mold <NUM> of the rotor <NUM> form a weak portion of the rotor <NUM>, so that the stiffness of the overall rotor <NUM> is affected. Accordingly, a problem arises in that the durability of the rotor <NUM> is deteriorated.

As a conventional technology for mitigating the above problems, <CIT> discloses a rotor for a motor.

The rotor for a motor according to the above-described conventional technology includes: a rotating shaft <NUM>; a rotor core <NUM> configured to surround the outer circumferential surface of the rotating shaft <NUM>; a plurality of magnets <NUM> disposed on the outer circumferential surface of the rotor core <NUM> and configured to generate magnetic force; and a mold <NUM> configured to surround the magnets <NUM> and the rotor core <NUM> exposed between the magnets <NUM> through insert molding. A groove <NUM> formed in a direction identical to the longitudinal direction of the magnets <NUM> is formed between each pair of adjacent magnets <NUM> in the mold <NUM>. The grooves <NUM> reduce the thickness of the mold <NUM> between the magnets <NUM>. It is characterized in that the difference with respect to the thickness of the mold <NUM> outside the magnets <NUM> is maintained within <NUM>%.

However, the above-described conventional technology has a problem that natural demagnetization loss occurs because the cooling efficiency of the rotor is low.

Furthermore, in the conventional technology, a problem arises in that demagnetization loss occurs due to breakage, such as magnetization of the magnet and the breaking of the edge of magnets during embedding.

Furthermore, the PMG-type structures, such as that of the conventional technology, use only cross sections. Accordingly, they have problems in that they do not take full advantage of the Gauss magnetic nature and incur significantly high manufacturing cost because they require large magnets according to the capacity calculation.

<CIT> discloses a permanent magnet module for a rotor that is configured to be mounted to a rim of the rotor and that comprises a metallic main body, a first permanent magnet component, and a first non-magnetic component. <CIT> discloses rotor assembly including a centrally located tubular core, circular in cross section, and which is held in assembled relation with a pair of end plates having integral hubs adapted to support bars on their outer peripheries. <CIT> discloses a pole wheel having a magnetic system inserted in the periphery of the wheel as a preformed module.

The present invention has been conceived to overcome the above-described problems, and an object of the present invention is to provide a thin-plate module horseshoe-type PMG rotor for a motor, in which a core is divided into an iron core and a pole plate core without being molded and magnets are assembled therebetween.

The invention refers to a thin-plate modular horseshoe-type permanent magnet rotor, for a motor, as defined in the independent claim <NUM>.

The following optional aspects of the invention are defined in the appended dependent claims.

The non-conductor shaft may be made of an aluminum material.

Each of the parts of the iron core may be configured such that an arc-shaped inner ground surface is formed to come into contact with the outer circumferential surface of the non-conductor shaft, two magnet attachment surfaces bent by <NUM>° are formed on the surface opposite to the inner ground surface, a recessed space internally recessed is formed in both outer side ends of the magnet attachment surface, a first rail groove configured to extend in a T shape may be formed by cutting the center bent corner of the magnet attachment surfaces in a longitudinal direction, and a location guide protrusion configured to be engaged with the location guide groove of the non-conductor shaft may be formed on the inner ground surface.

Each of the first core fixing means may include a first plate-shaped nut configured to simultaneously press and come into contact with both side ends of two opposite parts of the iron core in a longitudinal direction at a <NUM>-divided boundary of the iron core, and a first fastening means configured to fix the first plate-shaped nut to the non-conductor shaft.

Each of the boundary guide pins may be a plate member that has an I-shaped cross section and extends in the longitudinal direction of the iron core.

Each of the magnets may be formed by combining a plurality of sub-unit permanent magnets.

Each of the parts of the pole plate core may be configured to form an outer ground surface in an arc shape, to form two magnet facing surfaces, bent inward by <NUM>°, on the inner surface of the outer ground surface, to form stop protrusions, recessed inward, on both ends of the outer ground surface, and to form a second rail groove, configured such that the inside thereof is expanded in a T-shape, by cutting the bent corners of magnet facing surfaces in a longitudinal direction.

Each of the second core fixing means may include a second plate-shaped nut configured to be inserted into the first rail groove of the iron core in a longitudinal direction, a pressing member configured to be inserted into the stop protrusion of each of the parts of the pole plate core in the longitudinal direction, and a second fastening means configured to pass through the pressing member and to be screwed with a second plate-shaped nut to press and fix each of the parts of the pole plate core.

A first cooling passage configured such that cooling air circulates therethrough may be formed using the recessed space of the iron core, a second cooling passage configured such that cooling air circulates therethrough may be formed in the inner center of each of the parts of the pole plate core in which the boundary guide pin is installed, a third cooling passage configured such that cooling air circulates therethrough may be formed at both ends of each of the parts of the pole plate core, and a plurality of fourth cooling passages configured to pass through the iron core in a longitudinal direction may be formed.

The above and other objects, features, and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:.

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

<FIG> is an exploded perspective view showing a thin-plate module horseshoe-type PMG rotor for a motor according to the present invention, <FIG> is an assembled perspective view showing the thin-plate module horseshoe-type PMG rotor for a motor according to the present invention, and <FIG> is a magnetic force diagram showing the thin-plate module horseshoe-type PMG rotor for a motor according to the present invention.

Referring to <FIG>, the thin-plate module horseshoe-type PMG rotor for a motor according to the present invention basically includes a main shaft <NUM>, a non-conductor shaft <NUM>, first core fixing means <NUM>, boundary guide pins <NUM>, magnets <NUM>, a pole plate core <NUM>, and second core fixing means <NUM>.

The main shaft <NUM> serves as an output shaft that outputs the rotational force of the rotor to the outside, and is a round rod-shaped member fabricated in the longitudinal direction thereof.

Next, the non-conductor shaft <NUM> will be described.

The main shaft <NUM> is axially coupled into the cylindrical center portion of the non-conductor shaft <NUM>, and a plurality of location guide grooves <NUM> is formed on the outer surface of the non-conductor shaft <NUM> in the longitudinal direction thereof. The location guide grooves <NUM> are shaped in the form of slit grooves cut in the longitudinal direction thereof.

In this case, the non-conductor shaft <NUM> may be made of an aluminum material.

Next, an iron core <NUM> will be described.

The iron core <NUM> is divided into four parts and coupled to the outer circumferential surface of the non-conductor shaft <NUM>.

Each of the parts of the iron core <NUM> is configured such that an arc-shaped inner ground surface <NUM> is formed to come into contact with the outer circumferential surface of the non-conductor shaft <NUM>, two magnet attachment surfaces <NUM> bent by <NUM>° are formed on a surface opposite to the inner ground surface <NUM>, a recessed space <NUM> internally recessed is formed in both outer side ends of the magnet attachment surface <NUM>, a first rail groove <NUM> configured to extend in a T shape is formed by cutting the center bent corner of the magnet attachment surfaces <NUM> in the longitudinal direction, and a location guide protrusion <NUM> configured to be engaged with the location guide groove <NUM> of the non-conductor shaft <NUM> is formed on the inner ground surface <NUM>.

In this case, a plurality of fourth cooling passages <NUM> may be formed to pass through the iron core <NUM> in the longitudinal direction.

Next, each of the first core fixing means <NUM> will be described.

The first core fixing means <NUM> fixes both side ends of two adjacent parts of the iron core <NUM> to the non-conductor shaft <NUM> by pressing both side ends of two adjacent parts of the iron core <NUM> at a four-divided boundary of the iron core <NUM>.

The first core fixing means <NUM> includes a first plate-shaped nut <NUM> configured to simultaneously press and come into contact with both side ends of two opposite parts of the iron core <NUM> in the longitudinal direction at a <NUM>-divided boundary of the iron core <NUM>, and a first fastening means <NUM> configured to fix the first plate-shaped nut <NUM> to the non-conductor shaft <NUM>.

Next, each of the boundary guide pins <NUM> will be described.

The boundary guide pin <NUM> is coupled to form a longitudinal wall outside the first core fixing means <NUM>.

The boundary guide pin <NUM> is a plate member that has an I-shaped cross section and extends in the longitudinal direction of the iron core <NUM>.

Next, the magnets <NUM> will be described.

The magnets <NUM> are attached in the eight directions of the outer surfaces of the iron core <NUM>. Each of the magnets <NUM> may be composed of a single permanent magnet, or may be formed by combining a plurality of sub-unit permanent magnets, as disclosed in the accompanying drawings.

Next, the pole plate core <NUM> will be described.

The pole plate core <NUM> is divided into four parts to surround the magnets <NUM>.

Each of the parts of the pole plate core <NUM> is configured to form an outer ground surface <NUM> in an arc shape, to form two magnet facing surfaces <NUM>, bent inward by <NUM>°, on the inner surface of the outer ground surface <NUM>, to form stop protrusions <NUM>, recessed inward, on both ends of the outer ground surface <NUM>, and to form a second rail groove <NUM>, configured such that the inside thereof is expanded in a T-shape, by cutting the bent corners of the magnet facing surfaces <NUM> in the longitudinal direction.

Next, the second core fixing means <NUM> will be described.

The second core fixing means <NUM> fixes the electrode plate core <NUM> to the iron core <NUM> by compressing the pole plate core <NUM> onto the iron core <NUM>.

Each of the second core fixing means <NUM> includes a second plate-shaped nut <NUM> configured to be inserted into the first rail groove <NUM> of the iron core <NUM> in the longitudinal direction, a pressing member <NUM> configured to be inserted into the stop protrusion <NUM> of each of the parts of the pole plate core <NUM> in the longitudinal direction, and a second fastening means <NUM> configured to pass through the pressing member <NUM> and to be screwed with the second plate-shaped nut <NUM> to press and fix each of the parts of the pole plate core <NUM>.

According to the present invention described above, the heat generation of the rotor may be minimized by forming a plurality of cooling passages as follows:
According to the present invention, a first cooling passage <NUM> configured such that cooling air circulates therethrough may be formed using the recessed space <NUM> of the iron core <NUM>, a second cooling passage <NUM> configured such that cooling air circulates therethrough may be formed in the inner center of each of the parts of the pole plate core <NUM> in which the boundary guide pin <NUM> is installed, a third cooling passage <NUM> configured such that cooling air circulates therethrough may be formed at both ends of each of the parts of the pole plate core <NUM>, and a plurality of fourth cooling passages <NUM> configured to pass through the iron core <NUM> in the longitudinal direction may be formed.

In the above-described present invention, the core is not manufactured by molding, but is divided into the iron core <NUM> and the pole plate core <NUM> and then the magnets <NUM> are assembled therebetween. The magnets <NUM> may be disposed to be exposed to the surface. This method has an advantage in that there is no natural generation of demagnetization compared to the existing core assembly method.

Furthermore, according to the present invention, the plurality of cooling passages <NUM>, <NUM> and <NUM> is naturally formed in a structure in which the iron core <NUM>, the magnets <NUM>, and the pole plate core <NUM> are assembled together, and thus an advantage arises in that the heat of the rotor is naturally cooled.

Furthermore, according to the present invention, the main parts of the rotor are manufactured by assembly, so that a manufacturing process may be simplified and manufacturing efficiency may be increased.

Furthermore, according to the present invention, the main parts of the rotor may be easily disassembled and then replaced or repaired, so that advantages arise in that maintenance and repair are facilitated and management is also facilitated.

Furthermore, according to the present invention, as shown in <FIG>, the flow of magnetic force may be induced in a U-shape by disposing the boundary guide pins <NUM>. <FIG> shows the flow of magnetic force as in the case where four U-shaped horseshoe magnets are formed.

Accordingly, the present invention has advantages in that there may be prevented the defect in which the corners of magnets are broken when the molding core of the conventional rotor is assembled, it is easy to handle the rotor, and the demagnetization phenomenon at the corners of the magnets may be prevented.

Accordingly, according to the present invention, natural magnetic demagnetization loss is minimized, so that circulating magnetic force may be formed according to an increase in accelerated rotation.

Furthermore, according to the present invention, the flat magnets (magnets embedded in a molding frame) combined to have each salient polarity through surface adhesion and close tightening without demagnetization on the surfaces of the magnets and inside the conductor core generate magnetic force inside the inner frame of the iron core as in horseshoe magnets in the manner of being cyclical and uniform in the polarity ratio.

In addition, there is an advantage in that in order to reduce cost, several small magnets may be provided and combined and a winding salient pole-type brushless exciter functional element part is not required.

Although an example of a <NUM>-pole type rotor has been shown as the thin plate module horseshoe-type PMG rotor for a motor according to the present invention through the example of <FIG> above, there may be formed various types of magnetic force ranging from <NUM> to N poles.

According to the present invention, a combination of a various types of magnets may be possible, so that a combination of a plurality of small, rectangular, or square magnets <NUM> for each capacity may be easily selected, which allows the magnets to be easily inserted and magnetized inside the molding core during combination for each dimension, thereby providing the advantage of forming large horseshoe-shaped magnetic force.

According to the above-described present invention, there may be dealt with rotors of all capacities from small to medium-large capacity rotors, mass production is easy, and manufacturing cost and prime cost are reduced.

The embedded magnets of the present invention may be embedded in the upper left and right poles at the center of the polarity, thus conforming to the theory of electromotive force according to the electromotive force of the driving field.

Moreover, the magnet embedding method of the present invention generates circulating magnetic force to form polarity using a negative electrode (-) and a positive electrode (+), magnet-embedded thin plate module (U-type) horseshoe-shaped magnetic force is stable because it may utilize the magnet nature of negative (-) and positive (+) polarities, and stator power obtained by the driving of the rotor is generated as the power of power generation.

According to the above-described present invention, the core is not manufactured by molding, but is divided into the iron core and the pole plate core and then the magnets are assembled therebetween. The magnets may be disposed to be exposed to the surface. This method has no natural generation of demagnetization compared to the existing core assembly method. The number of cooling passages is naturally formed in the assembly structure of the iron core, magnets, and pole plate core, and thus the heat of the rotor may be naturally cooled. The main parts of the rotor are manufactured by assembly, and thus there are achieved the effects of simplifying the manufacturing process and improving manufacturing efficiency.

Claim 1:
A thin-plate modular horseshoe-type permanent magnet rotor for a motor, the rotor comprising:
a main shaft (<NUM>);
a magnetically non-conductive shaft (<NUM>) axially coupled to an outer circumference of the main shaft (<NUM>);
an iron core (<NUM>) circumferentially divided into four equal parts and coupled to an outer circumferential surface of the magnetically non-conductive shaft (<NUM>);
first core fixing means (<NUM>) for pressing and fixing both circumferential side ends of each part of the iron core (<NUM>) to the magnetically non-conductive shaft (<NUM>) along four boundaries of the iron core (<NUM>);
magnets (<NUM>) attached to an outer surface of the iron core (<NUM>) in eight radial directions;
a pole plate core (<NUM>) circumferentially divided into four equal parts coupled to surround the magnets (<NUM>), wherein each part of the pole plate core (<NUM>) is coupled to magnets attached in two radial directions to two adjacent parts of the iron core (<NUM>);
second core fixing means for pressing and fixing both circumferential ends of each part of the pole plate core (<NUM>) to the iron core (<NUM>),
boundary guide pins (<NUM>) consisting of plate members coupled to the iron core (<NUM>) and the pole plate core(<NUM>) to form a wall outside the first core fixing means (<NUM>) in an axial direction.