WO2008060035A1

WO2008060035A1 - Outer rotor type motor and outdoor unit having the same

Info

Publication number: WO2008060035A1
Application number: PCT/KR2007/004520
Authority: WO
Inventors: Seong-Kook Cho; Jae-Boo Eom; Yoo-Sool Yoon; Young-Ho Hong
Original assignee: Lg Electronics Inc.
Priority date: 2006-11-15
Filing date: 2007-09-18
Publication date: 2008-05-22

Abstract

An outer rotor type motor comprises: a lower housing having a plurality of integral brackets or an additional supporting bracket; an upper housing coupled to the lower housing, and forming a closed inner space together with the lower housing; a stator fixedly-installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor for transmitting a rotational force. Foreign materials are prevented from being sucked into the outer rotor type motor, thereby enhancing a stability of the outer rotor type motor. Furthermore, since heat radiating fins are disposed at the lower housing and the upper housing, heat emitted from the stator is effectively radiated.

Description

OUTER ROTOR TYPE MOTOR AND OUTDOOR UNIT

HAVING THE SAME

Technical Field

[1] The present invention relates to an outer rotor type motor and an outdoor unit for an air conditioner having the same. Background Art

[2] As people in nations that belong to a tropical region have an enhanced life quality, a demand for a cooling device such as an air conditioner is increased. Especially, as buildings such as large restaurants or hotels are constructed, a demand for a large cooling device or a multi-type cooling device is increased. Nowadays, an outdoor unit having an outer rotor type motor is widely applied to the large cooling device or the multi-type cooling device.

[3] A stator on which a coil is wound is disposed at an inner side of the outer rotor type motor, and a rotor is disposed outside the stator as a magnet surrounds the coil of the stator. That is, the outer rotor type motor has a large inertia since it is rotated with the rotor. Accordingly, the outer rotor type motor is mainly used at an air conditioner of a large capacity.

[4] In a tropical area like a sandy desert, the outdoor unit has to be installed so that sand can not be introduced thereinto. When the outdoor unit is operated, the sand may be sucked into the outdoor unit by a suction force of the outer rotor type motor. Here, the sand is disposed at an air gap between the stator and the rotor, thereby not rotating the rotor and damaging the outer rotor type motor. Disclosure of Invention Technical Problem

[5] To solve the problem, a housing of the outer rotor type motor is sealed thus to shield between the stator and the rotor, thereby preventing sand from being introduced between the stator and the rotor. However, when the outer rotor type motor is sealed, a small amount of convection currents occur thus to increase the temperature of the coil. As a result, an insulation characteristic is destroyed thus to lower a reliability of the outer rotor type motor. Technical Solution

[6] Therefore, it is an object of the present invention to provide an outer rotor type motor capable of having an enhanced reliability by preventing sand from being sucked thereinto even when being mounted at an outdoor unit positioned at a sandy area.

[7] It is another object of the present invention to provide an outer rotor type motor capable of preventing a damage by preventing an inner temperature thereof from being excessively increased.

[8] To achieve these objects, there is provided an outer rotor type motor, comprising: a lower housing; an upper housing coupled to the lower housing, and forming a closed inner space together with the lower housing; a stator fixedly-installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor for transmitting a rotational force.

[9] To achieve these objects, there is also provided an outdoor unit having an outer rotor type motor, comprising: a casing; a compressor disposed in the casing; a condenser connected to an outlet of the compressor; and an outer rotor type motor, comprising: a lower housing integrally having a plurality of brackets fixed to inside of the casing on an outer circumferential surface thereof, and forming an inner space; an upper housing coupled to the lower housing, and closing the inner space of the lower housing; a stator fixedly installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor, for transmitting a rotational force.

[10] According to another aspect of the present invention, the outdoor unit having an outer rotor type motor comprises: a casing; a compressor disposed in the casing; a condenser connected to an outlet of the compressor; and an outer rotor type motor, comprising: a supporting bracket fixed to inside of the casing; a lower housing coupled to the supporting bracket and having an inner space; an upper housing coupled to the lower housing, and closing the inner space of the lower housing; a stator fixedly- installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor, for transmitting a rotational force.

Advantageous Effects

[11] In the present invention, the outer rotor type motor is disposed at the lower housing integrally having the plurality of brackets. Accordingly, foreign materials are prevented from being sucked into the outer rotor type motor, thereby enhancing a stability of the outer rotor type motor. Furthermore, since heat radiating fins are disposed at the lower housing and the upper housing, heat emitted from the stator is effectively radiated. Brief Description of the Drawings

[12] FIG. 1 is a sectional view showing an outer rotor type motor according to a first embodiment of the present invention;

[13] FIG. 2 is a disassembled perspective view showing the outer rotor type motor according to a first embodiment of the present invention;

[14] FIG. 3 is a perspective view showing an upper surface of a lower housing of the outer rotor type motor according to a first embodiment of the present invention;

[15] FIG. 4 is a perspective view showing a lower surface of the lower housing of the outer rotor type motor according to a first embodiment of the present invention;

[16] FIG. 5 is an enlarged perspective view of 'A'in FIG. 3;

[17] FIG. 6 is a perspective view showing a power connector and a hole sensor of the outer rotor type motor according to a first embodiment of the present invention;

[18] FIG. 7 is a sectional view showing an outer rotor type motor according to a second embodiment of the present invention; and

[19] FIG. 8 is a disassembled perspective view showing an outer rotor type motor according to a second embodiment of the present invention. Best Mode for Carrying Out the Invention

[20] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

[21] As shown in FIGS. 1 and 2, an outer rotor type motor according to the present invention comprises a lower housing 10 having an inner space; an upper housing 20 coupled to the lower housing 10, and closing the inner space of the lower housing 10; a stator 30 fixedly-installed at the inner space of the lower housing 10; a rotor 40 rotatably disposed on an outer circumferential surface of the stator 30; and a rotation shaft 50 coupled to the center of the rotor 40 for transmitting a rotational force.

[22] The lower housing 10 is formed so that a bottom surface thereof can be closed, or so that an opening of the bottom surface can be covered by a covering plate (not shown). The covering plate is formed in a disc shape so as to integrally cover the opening of the bottom surface, or is formed in a fan shape so as to individually cover the opening by each fan.

[23] As shown in FIGS. 3 and 4, the lower housing 10 is formed in a bowl shape having a certain depth, and a plurality of brackets 11 for fixing the outer rotor type motor are integrally formed on an outer circumferential surface thereof with an angle of 120 therebetween. A shaft supporting hole 12 for rotatably coupling the rotation shaft 50 is formed at the center of the lower housing 10. A shaft supporting protrusion 13 for supporting the rotation shaft 50 in a radius direction is protruding from the periphery of the shaft supporting hole 12 with a certain height in a shaft direction. A stator mounting protrusion 14 for mounting a stator core 31 of the stator 30 is formed at an outer bottom surface of the shaft protrusion 13. An upper reinforcing rib 15 for enhancing an intensity of the lower housing 10 is formed on an inner circumferential surface of the stator mounting protrusion 14 in a radius direction towards the shaft protrusion 13.

[24] An aligning recess (or an aligning protrusion) 14a for inserting an aligning protrusion or an aligning recess (not shown) of the stator 30 thereby determining a position where the stator 30 is to be mounted at the time of coupling the stator 30 is formed at the stator mounting protrusion 14. A stator fixing hole 14b for fixing the stator 30 is formed at a portion of the stator mounting protrusion.

[25] As shown in FIG. 3, a downward reinforcing rib 16 is formed in a radius direction on an outer circumferential surface of the shaft protrusion 13 towards a lower surface of the lower housing 10. A drain hole 17 through which condensing water is discharged out is formed at a bottom surface of the lower housing 10. A plurality of heat radiating fins 10a are formed on an outer circumferential surface of the lower housing 10 in a radius direction.

[26] Preferably, the drain hole 17 is formed at each portion of the inner space of the lower housing 10 partitioned from each other by the upper reinforcing ribs 15 so as to rapidly discharge condensing water out.

[27] As shown in FIGS. 5 and 6, a plurality of bushing mounting holes 19 are formed at one edge of the lower housing 10, and a plurality of bushings 61 for passing a lead line for a power connector and a lead line for a hole sensor are coupled to the bushing mounting hole 19.

[28] The bushing mounting hole 19 is formed so that both surfaces contacting an edge of the lower housing 10 can be communicated with each other. The bushing 61 is inserted into one surface, and another surface is hermetically covered by a hole covering plate 62.

[29] The bushing 61 is formed in a plate shape, and a lead line passing hole 61a is formed at a central portion of the bushing 61 as a boss shape. A sealing recess 61b is formed at an edge surface of the bushing 61 so as to be inserted into a cut surface of the bushing mounting hole 19 or an edge surface of the hole covering plate 62.

[30] A power connector 63 and a hole sensor 64 are respectively disposed at a bottom surface of the lower housing 10. A lead line Ll for a power connector and a lead line for a hole sensor (not shown) for preventing introduction of moisture inside the lower housing 10 are respectively connected to the power connector 63 and the hole sensor 64 by being molded (63a and 64a).

[31] As shown in FIG. 5, a plurality of coupling protrusions 18 and 22 for coupling the lower housing 10 and the upper housing 20 to each other by bolts are respectively formed on an outer circumferential surface of an opening of the lower housing 10 and an outer circumferential surface of an opening of the upper housing 20. One of the coupling protrusions 18 and 22 (the coupling protrusion 18 in drawing) is provided with a bolt head fixing recess or a nut fixing recess having the same shape as an angular shape of a bolt head or a nut and concaved to insert the bolt head or the nut.

[32] As shown in FIGS. 1 and 2, the upper housing 20 is formed in a cap shape having a certain depth, and a shaft supporting recess 21 for receiving a coupled portion between the rotor 40 and the rotation shaft 50 are convexed outwardly at a central portion of the upper housing 20 so as to minimize a size of the outer rotor type motor. A coupling protrusion 22 engaged with the coupling protrusion 18 of the lower housing 10 is formed at an edge of the upper housing 20. Heat radiating fins (not shown) may be formed on an outer circumferential surface of the upper housing 20. Preferably, the heat radiating fins are disposed in a radius direction with an angle of 3-15 therebetween like in the lower housing 10, thereby enhancing a heat radiating effect.

[33] As shown in FIGS. 1 and 2, the stator 30 includes a stator core 31 having a ring shape so as to form a magnetic path, a winding coil 32 wound on a teeth portion 31b of the stator core 31, and an insulator 33 disposed between the stator core 31 and the winding coil 32.

[34] The stator core 31 is composed of a yoke portion 31a having a ring shape so as to form a magnetic path, and a plurality of teeth portions 31b radially disposed on an outer circumferential surface of the yoke portion 31a for winding the winding coil 32 thereon.

[35] The insulator 33 is formed to cover an outer circumferential surface of the teeth portion 31b, and one side surface of the yoke portion 31a is exposed to the air thus to directly come in contact with the lower housing 10.

[36] As shown in FIGS. 1 and 2, the rotor 40 is composed of a rotation plate 41 coupled to an upper end of the rotation shaft 50; and a plurality of magnets 42 disposed on an outer circumferential surface of the stator 30 with a certain air gap along a circumferential direction so that N and S poles can be alternately disposed with each other, and fixed to an inner circumferential surface of the rotation plate 41.

[37] Preferably, the magnet 42 is disposed so that a height thereof can be aligned with a height of the stator 30 so as to enhance an efficiency of the outer rotor type motor.

[38] An operation of the outer rotor type motor according to the present invention will be explained.

[39] When power is supplied to the winding coil 32 of the stator 30, the rotor 40 is rapidly rotated. A rotational force of the rotor 40 is transmitted to a fan coupled to an end of the rotation shaft 50 through the rotation shaft 50, thereby rotating the fan.

[40] While the rotor 40 of the outer rotor type motor is rapidly rotated, a suction force is generated. Accordingly, when an outdoor unit having the outer rotor type motor is installed at a sandy area, sand may be introduced into the housing by the suction force of the rotor 40. However, since the lower housing 10 and the upper housing 20 are formed to have a closed type, foreign materials such as sand are prevented from being sucked into the outer rotor type motor. Accordingly, a damage of the outer rotor type motor due to suction of foreign materials into an air gap between the stator 30 and the rotor 40 is prevented.

[41] As the housing of the outer rotor type motor is closed, heat of a high temperature generated from the stator 30 inside the housing is not easily emitted outwardly, and thus a function of the outer rotor type motor may be lowered. However, the stator 30 is directly adhered to the lower housing 10, or a heat block 61 adhered to the stator 30 is adhered to the lower housing 10, and a plurality of heat radiating fins 10a are formed on outer circumferential surfaces of the lower housing 10 and the upper housing 20. Accordingly, heat generated from the stator 30 is rapidly emitted outwardly, thereby preventing a function of the outer rotor type motor from being lowered.

[42] Furthermore, condensing water generated from inside of the outer rotor type motor is outwardly emitted through the drain hole 17, thereby preventing a damage of the outer rotor type motor due to moisture inside the outer rotor type motor.

[43] Besides, since the lower housing 10 is integrally provided with the brackets 11 for fixing the outer rotor type motor, an assembly process of the outer rotor type motor can be simplified thus to reduce a fabrication cost.

[44] Also, a bolt head fixing recess or a nut inserting recess 18a having a shape corresponding to a shape of a bolt head or a nut is formed at the coupling protrusion 18 of the lower housing 10 or the coupling protrusion 22 of the upper housing 20. As a result, the lower housing 10 and the upper housing 20 can be more easily assembled to each other thus to reduce a fabrication cost. Mode for the Invention

[45] In the outer rotor type motor according to the first embodiment, the brackets are integrally formed on the outer circumferential surface of the lower housing. However, in the outer rotor type motor according to the second embodiment, an additional supporting bracket is assembled to the outer circumferential surface of the lower housing.

[46] As shown in FIGS. 7 and 8, the outer rotor type motor according to the second embodiment comprises: a supporting bracket fixed to a positoin where the outer rotor type motor is to be mounted; a lower housing 10 coupled to the supporting bracket 70 and having an inner space; an upper housing 20 coupled to the lower housing 10, and closing the inner space of the lower housing 10; a stator 30 fixedly-installed at the inner space of the lower housing 10; a rotor 40 rotatably disposed on an outer circumferential surface of the stator 30; and a rotation shaft 50 coupled to the center of the rotor 40, for transmitting a rotational force.

[47] The outer rotor type motor according to the second embodiment has the same con- figuration as the outer rotor type motor according to the first embodiment in the aspect of the lower housing 10, the upper housing 20, the stator 30, the rotor 40, and the rotation shaft 50 except the following. In the outer rotor type motor according to the second embodiment, not the integral brackets 11 of the first embodiment but the additional supporting bracket 70 is provided at the lower housing 10.

[48] The supporting bracket 70 includes a shaft supporting portion 71 for rotatably coupling the rotation shaft 50 and supporting the rotation shaft 50 in a radius direction; and a plurality of brackets 72 (three brackets in drawing) integrally disposed on an outer circumferential surface of the shaft supporting portion 71 with an angle of approximately 120 , for supporting the lower housing 10 thereon.

[49] The outer rotor type motor according to the present invention may be generally installed at an outdoor unit.

[50] The outdoor unit comprises a casing; a compressor disposed in the casing; a condenser connected to an outlet of the compressor; and an outer rotor type motor disposed at one side of the condenser.

[51] The compressor and the condenser have the same configuration as those applied to a general outdoor unit.

[52] The outer rotor type motor comprises: a lower housing having a plurality of integral brackets or an additional supporting bracket on an outer circumferential surface thereof, the bracket is fixed to a position where the outer rotor type motor is to be mounted, and forming an inner space; an upper housing coupled to the lower housing, and closing the inner space of the lower housing; a stator fixedly installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor, for transmitting a rotational force.

[53] The outer rotor type motor has the same configuration and operation as those of the aforementioned one, and thus its detailed explanation will be omitted.

[54] It will also be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

[I] An outer rotor type motor, comprising: a lower housing; an upper housing coupled to the lower housing, and forming a closed inner space together with the lower housing; a stator fixedly-installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor for transmitting a rotational force. [2] The outer rotor type motor of claim 1, wherein a plurality of brackets are integrally formed on an outer circumferential surface of the lower housing, and is fixed to a position where the outer rotor type motor is to be mounted. [3] The outer rotor type motor of claim 1, wherein an additional supporting bracket is assembled to an outer circumferential surface of the lower housing, and is fixed to a position where the outer rotor type motor is to be mounted. [4] The outer rotor type motor of claim 1, wherein a drain hole through which condensing water is discharged out is formed at a bottom surface of the lower housing. [5] The outer rotor type motor of claim 1, wherein one or more reinforcing ribs for enhancing an intensity of the lower housing are formed at the lower housing. [6] The outer rotor type motor of claim 1, wherein a bottom surface of the lower housing is formed to have a closed shape. [7] The outer rotor type motor of claim 1, wherein the lower housing has an opening partially formed at a bottom surface thereof, and the opening is covered by a covering plate. [8] The outer rotor type motor of claim 7, wherein the covering plate is formed in a disc shape so as to integrally cover the opening of the bottom surface, or is formed in a fan shape so as to individually cover the opening by each fan. [9] The outer rotor type motor of claim 1, wherein a shaft supporting recess for receiving a coupled portion between the rotor and the rotation shaft are con vexed outwardly with a predetermined height at a central portion of the upper housing. [10] The outer rotor type motor of claim 1, wherein the lower housing and the upper housing are coupled to each other by a plurality of bolts and nuts.

[I I] The outer rotor type motor of claim 10, wherein a bolt head fixing recess or a nut fixing recess having the same shape as an angular shape of a bolt head or a nut is concaved at one of the lower housing and the upper housing so as to insert the bolt head or the nut. [12] The outer rotor type motor of claim 1, wherein the stator core comprises: a yoke portion having a ring shape so as to form a magnetic path; and a plurality of teeth portions radially disposed on an outer circumferential surface of the yoke portion for winding the winding coil thereon, and wherein an insulator is disposed to cover an outer circumferential surface of the teeth portion, and one side surface of the yoke portion is exposed to air thus to directly come in contact with the lower housing.

[13] The outer rotor type motor of claim 12, wherein a stator mounting protrusion for mounting a stator core of the stator is protruding from a bottom surface of the lower housing with a certain height.

[14] The outer rotor type motor of claim 13, wherein an aligning recess (or an aligning protrusion) for coupling an aligning protrusion or an aligning recess of the stator thereby determining a mounting position of the stator is formed at the stator mounting protrusion.

[15] The outer rotor type motor of claim 13, wherein one or more reinforcing ribs are disposed on an inner circumferential surface of the stator mounting protrusion in a radial direction towards a center of a housing bracket.

[16] The outer rotor type motor of claim 1, wherein one or more bushing mounting holes are formed at the e lower housing, and one or more bushings for passing a lead line for a power connector and a lead line for a hole sensor are coupled to the bushing mounting hole.

[17] The outer rotor type motor of claim 16, wherein the bushing mounting hole is formed so that both surfaces contacting an edge of the lower housing can be communicated with each other, the bushing is inserted into one surface, and another surface is hermetically covered by a hole covering plate.

[18] The outer rotor type motor of claim 16, wherein the bushing is formed in a plate shape, a lead line passing hole is formed at a central portion of the bushing as a boss shape, and a sealing recess is formed at an edge surface of the bushing so as to be inserted into a cut surface of the bushing mounting hole or an edge surface of the hole covering plate.

[19] The outer rotor type motor of claim 1, wherein a lead line for a power connector and a lead line for a hole sensor are respectively connected to a power connector and a hole sensor disposed at the lower housing by a molding process.

[20] An outdoor unit having an outer rotor type motor, comprising: a casing; a compressor disposed in the casing; a condenser connected to an outlet of the compressor; and an outer rotor type motor, comprising: a lower housing integrally having a plurality of brackets fixed to inside of the casing on an outer circumferential surface thereof, and forming an inner space; an upper housing coupled to the lower housing, and closing the inner space of the lower housing; a stator fixedly installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor, for transmitting a rotational force.

[21] An outdoor unit having an outer rotor type motor, comprising: a casing; a compressor disposed in the casing; a condenser connected to an outlet of the compressor; an outer rotor type motor, comprising: a supporting bracket fixed to inside of the casing; a lower housing coupled to the supporting bracket and having an inner space; an upper housing coupled to the lower housing, and closing the inner space of the lower housing; a stator fixedly-installed at the inner space of the lower housing; a rotor rotatably disposed on an outer circumferential surface of the stator; and a rotation shaft coupled to the center of the rotor, for transmitting a rotational force.