JP2002017066A - Radiating structure for small cylindrical coreless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small coreless motor unit of which outer diameter is equal to or less than ϕ30 mm and which includes measures against heat generation capable of withstanding severe usage such as repetitive forward and reverse rotation, in the small coreless motor used for a sever operating drive part such as the inside of a special measuring instrument, and 'radicon' (R) model. SOLUTION: In this coreless motor provided with a cup-type rotor in which one axial opening end of a cylindrical winding coil is fixed to a rotary shaft, an integral or separate heat dissipater with excellent heat conductivity is newly attached to part or the whole surface of the single side of a resin mold body disposed between the rotary shaft and the winding coil located on the other end of the opening of the rotor winding coil. Indirect contact with the air in the motor with the rotation of the rotor, heat radiation to the internal air, and heat conduction with fitting contact from the heat dissipater brought into direct contact with the winding coil to the rotary shaft from the rotary shaft to a bearing house on the stator side and a subsequent outer housing, are performed subsequently, thereby effectively radiation heat generation from the winding coil on the surface of the outer housing having the largest area of the surface brought into contact with the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coreless motor, and more particularly to a cylindrical coreless motor having a cup-shaped rotor winding coil, which is used in a special measuring instrument or in a severe operation driving part such as a radio control model. More specifically, the present invention relates to a heat countermeasure for a small coreless motor unit having a motor unit outer diameter of 30 mm or less and withstanding a severe use in which forward and reverse rotations are constantly repeated.

[0002]

2. Description of the Related Art Conventionally, in a general coreless motor, a cylindrical cup-shaped housing 1 as shown in FIG.
A bearing house 2 is fitted and supported at one end of the housing 1, a cylindrical magnet 3 is inserted into the outer diameter side of the bearing house 2, and a bearing 4 is spaced apart from the inner diameter at the end. These are assembled as a housing side of a stator portion of the motor.

On the other hand, a cylindrical winding coil 6 shown in the figure is inserted and opposed at a position in which the magnet 3 is included, that is, at a position where a gap between the inner wall of the housing 1 and the outer diameter of the magnet 3 is maintained. A commutator that is a commutation mechanism
7 is a resin molded body 10 in which the shaft 5 serving as a rotation axis is arranged and fixed at the center of the coil 6 by insert molding.
The whole rotor portion composed of the above is assembled by rotatably supporting a shaft 5 with the bearing 4 of the stator portion and holding a brush 8 slidably mounted on the commutator 7 at the end of the housing case on the opening side. There is a small coreless motor in which a fixed brush stand 9 is fitted and attached, and the inside of the motor housing is sealed.

[0004] As described above, the winding coil 6 for generating the rotational torque is designed to rotate with a certain gap between the stator-side housing 1 and the magnet 3. Is almost closed, heat generated in the winding coil 6 due to excessive energization is convected in the motor space via the internal air, and the metal housing 1 itself heats up eventually. Will be done.

[0005] This is because the supporting member for fixing and holding the winding coil 6 concentrically of the shaft 5 is made of a resin material, and the supporting member itself cannot transmit heat (heat conductivity) of the winding coil 6. However, this heat problem did not occur for a very common normal use purpose, and the heat generation problem was almost completely eliminated by natural heat radiation.

However, in a drive motor for a radio-controlled model which repeats normal rotation and reverse rotation as a special purpose and application, since the overload applied to the coil is almost continuously generated, the overload during the overload is almost continuous. The heat generated by the coil 6 is rapidly increased, and the only structural cooling is heat dissipation into the air inside the motor. Is
It is gradually deformed by heat.
May interfere with the stator side member, cause insulation failure, and suddenly become unable to rotate.

[0007]

As described above, the conventional small motor using the coreless structure of the internally sealed type as described above does not take measures against heat generation. Even when mounted on a car radio control car model, the problem of heat generation always occurs, and there is a serious drawback that power performance is deteriorated and reliability and durability are remarkably reduced.

That is, in a use in which the operation pattern of a radio-controlled vehicle repeats an operation pattern of high-speed continuous high-speed continuous operation, reverse rotation overload of braking operation, high-speed motion during acceleration again, etc. The load (heat generation) applied to the motor itself is often severe, and it has been desired to take measures against the heat of a small driving motor in a marginal use region. As described above, the current flowing through the winding coil is large, and a decrease in motor efficiency has been a problem due to an increase in internal temperature due to heat generation.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a coreless motor having a cup-shaped rotor in which the other end in the axial direction of a cylindrical winding coil is fixed to a rotating shaft. A part or all of one side of the resin mold interposed between the rotating shaft and the winding coil located on the other end side of the opening of the winding coil, a heat sink with excellent thermal conductivity, integrated or separate, is provided. It is to be newly installed.

[0010] Thus, not only the indirect contact with the air inside the motor due to the rotation operation of the rotor portion, and the heat dissipation into the inside air, but also the rotation from the heat sink directly in contact with the winding coil to the rotating shaft. The heat conduction accompanying the contact from the shaft to the bearing housing on the stator side and the housing of the exterior that follows is naturally performed, and finally the surface area of the exterior housing that has the largest surface area to be contacted with the outside is The heat is efficiently dissipated. It is even more effective when the heat sink is used as a copper-based or aluminum-based alloy or carbon-based material having good thermal conductivity.

[0011] Further, by making the end flat surface of the heat radiating plate contact the inner peripheral surface of the winding coil and the outer peripheral surface of the rotating shaft with a large fitting area, heat conduction is performed reliably and quickly, and furthermore, the winding coil It is also effective in dissipating heat that the resin mold body connecting the one end and the rotating shaft and the support base integrated with the heat sink have a large number of fins or openings for blowing air. Further, iron loss can be reduced.

Further, it is preferable that the bearing and the bearing house which support the rotating shaft on the stator side, and the entire housing which holds and fixes the bearing house are made of a heat-radiating material having good thermal conductivity. For example, a copper-based or aluminum-based alloy for weight reduction may be used.

For example, on the outer peripheral surface of the housing case,
Providing an uneven cooling fin shape is also effective as a means of improving heat dissipation efficiency. In addition, a part or the whole of the outer surface of the brush base of the end cap incorporated into the opening end of the housing has thermal conductivity. It is also effective to provide a heat sink as an excellent uneven cooling fin member. Naturally, the cooling fin portion and the heat sink portion are desirably made of a copper-based material, but may be changed to another heat conductive material (aluminum-based alloy or the like) due to molding work or cost and weight reduction. However, the present invention does not greatly depart from the object, operation, and effect of the present invention, and there is no particular problem in specification.

The heat countermeasure structures of the small coreless motor of the present invention described above may be individually employed, but more excellent effects can be expected by combining some of the structures.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below. FIG. 1 is a side sectional view of a coreless motor in a form in which a heat sink is provided on a rotor portion.
1 is a metal housing, 2 is a metal bearing house, 3 is a cylindrical rare-earth magnet, 4 is a bearing, 5 is a rotating shaft, and a rotating shaft 5 has a commutator 7 at one end. A resin mold body 10 that is arranged uniformly in the circumferential direction and connects the winding coil 6 and the shaft 5 is provided integrally, and a heat sink 30 is insulated on a support base portion of the disk-shaped resin mold body 10. It is provided integrally with the sheet 31 interposed therebetween.

As shown in the figure, the heat radiating plate 30 has one end in contact with the inner peripheral surface of the coil 6 and the other central portion fixed to the shaft 5 serving as a rotating shaft by press-fitting.
In the portion of the surface which is in contact with the disk shape of 0, a number of fins 32 or openings 33 for air blowing are provided as shown in FIGS.
One end of the formed winding coil 6 is adhesively fixed on the inner peripheral surface,
The winding coil 6 and the segment portion of the commutator 7 are electrically connected to the brush 8 to form a drive rotor unit.

The arrows shown in FIG. 3 indicate the directions in which the heat generated in the winding coil is transmitted through the heat radiating plate and conduct heat, respectively, and finally radiate on the exterior surface of the housing in contact with the outside air. This provides a mechanism for radiating heat inside the motor.

At this time, it is also possible to finish the exterior part of the housing 1 in a fine uneven shape as shown in FIG. 4 to substantially increase the surface area and improve the heat exchange efficiency.

Further, as shown in FIG. 5, in addition to the above-mentioned related specifications, a part or the whole of the outer surface of the brush stand 9 incorporated in the opening end of the housing 1 is provided with an uneven cooling having excellent heat conductivity. It is also effective to provide a heat sink 40 member as a fin. As a result, heat is conducted as indicated by the arrow in FIG. 6, and the surface area of the outer end face of the brush stand 9 is greatly increased as compared with the case shown in FIG. 3, thereby further increasing the cooling efficiency.

As shown in FIGS. 1 and 5, by forming a plurality of circular or fan-shaped holes 33 shown in FIGS. 2A and 2B and forming the fins 32 on the plate surface. When the rotor rotates, the wind generated by the fins 32 stirs the entire motor interior including the winding coil 6 and the magnet 3 to circulate partial heat when the rotor rotates due to the air blowing structure of the resin mold body in the coreless motor. It is intended to be cooled.

It is effective that the fins 32 for blowing air are provided integrally with the heat sink 30 as shown in FIGS. 2 (a) and 2 (b). In particular, by providing the same hole corresponding to the heat sink in the resin mold body 10, if the hole of the heat sink 30 + the hole of the resin mold body are opened together, the flow of the air will be better, so the cooling effect And the mass of the rotor portion is reduced, so that the moment of inertia of the entire rotor portion can be reduced. Further, when a metal heat sink is used, iron loss can be reduced.

If a material having good heat conductivity is used as the heat sink 40, the surface area of the outer peripheral surface of the housing 1 is enlarged by the heat sink 40, so that the heat radiation of the entire motor can be improved. 4 and 5
If the fins 42 are integrally provided on the end surface of the heat sink 40 and the housing 1 is provided with a similar uneven shape as shown in an enlarged schematic diagram shown in FIG.

[0023]

As described above, according to the present invention, there is provided a coreless motor having a cup-shaped rotor in which the other end in the axial direction of the cylindrical coil is fixed to the rotating shaft. Because a heat sink with excellent thermal conductivity is newly attached integrally or separately to part or all of one surface of the resin mold body interposed between the rotating shaft and the winding coil located on the other end side of the part, Due to this, not only indirect contact with the air inside the motor due to the rotation operation of the rotor part, and heat dissipation into the internal air, but also from the heat sink directly in contact with the winding coil which is the heating part to the shaft of the rotating shaft, In addition, heat conduction accompanying the contact from the rotating shaft to the stator-side bearing house and the subsequent exterior housing is sequentially performed, and finally the surface layer of the exterior housing that has the largest surface area for contact with the outside (outside air). In heat generation from the winding coil which is a heat source is conducted efficiently.

Further, when the heat radiating plate is used as a copper or aluminum material having good thermal conductivity, the heat radiating effect is improved.

Further, by making the end surface of the heat radiating plate contact the inner peripheral surface of the winding coil and the outer peripheral surface of the rotary shaft with a large fitting area, heat conduction is performed reliably and quickly. Heat diffusion and heat dissipation inside the motor are provided by providing a large number of fin-shaped or opening holes for air blowing in the resin mold body that connects between one end of the Could be done.

Further, if the bearing and the bearing house for supporting the rotating shaft on the stator side and the entire housing for holding and fixing the bearing house are made of a heat-radiating material having good heat conductivity, the winding coil portion may be used. The generated heat could be quickly radiated to the outside, and the heat was not trapped inside the motor, allowing smooth cooling.

Further, an irregular cooling fin shape is formed on the outer peripheral surface of the housing case, and in addition, a part or the whole of the outer end surface of the brush base incorporated into the opening end of the housing is provided.
By providing a heat sink as a cooling fin having excellent thermal conductivity, the surface area of the entire motor exterior is increased, and heat radiation efficiency is improved.

With these heat countermeasures, the motor unit can be used in a special measuring device or a severely driven part such as a radio-controlled model with an outer diameter of 30 mm or less, and withstands severe use in which forward and reverse rotations are constantly repeated. Small-sized coreless motor units can be mass-produced, and stable power characteristics can be obtained even under high overload use conditions.

Further, in the small coreless motor provided with these cooling mechanisms, since the measures against heat generation are sufficiently taken, even if the motor is used for, for example, a model of a four-wheeled radio control car model, the heat generated by the drive motor can be reduced. No problems occur, no deterioration in power performance, high reliability and high durability are remarkably improved, and even during high-torque operation, the problem of a decrease in motor efficiency due to an increase in internal temperature due to heat generation can be solved. Serious defects of inoperability that had become a malfunction problem disappeared,
A high-performance small coreless motor for driving in a limited use area such as the above-mentioned radio-controlled model could be realized.

[Brief description of the drawings]

FIG. 1 is a side sectional structural view showing a configuration of a coreless motor according to an embodiment of the present invention.

FIGS. 2A and 2B are a front view and a side cross-sectional view illustrating an example of the shape of a heat sink according to the embodiment of the present invention.

FIG. 3 is a schematic side sectional view of the coreless motor showing a heat conduction path according to the embodiment of the present invention.

FIG. 4 is a schematic view showing an example of a heat radiation uneven shape of a housing exterior according to the embodiment of the present invention.

FIG. 5 is an explanatory view showing an example of a brush stand heat sink according to the embodiment of the present invention.

FIG. 6 is a schematic side sectional view of the coreless motor showing a heat conduction path according to the embodiment of the present invention.

FIG. 7 is a side sectional structural view showing an internal configuration of a conventional coreless motor.

[Explanation of symbols]

 1 Housing 2 Bearing house 3 Magnet 4 Bearing 5 Shaft (rotating shaft) 6 Winding coil 7 Commutator 8 Brush 9 Brush base 10 Resin molded body 11 Lead wire 30 Heat sink 31 Insulating sheet 32, 42 Fin 33 Hole 40 Heat sink

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 5H604 AA03 BB01 BB07 BB14 CC02 CC04 CC12 DA14 DB01 PB01 PB02 PB03 5H605 AA01 BB05 BB09 CC02 DD12 EA07 FF03 5H609 BB06 PP01 PP02 PP05 PP06 PP07 PP09 PP10 PP11 PP13 QQRR 5H623 AA08 BB07 GG12 GG18 HH06 HH10 JJ03 LL09 LL13 LL14

Claims (9)

[Claims] 1. A coreless motor having a cup-shaped rotor in which the other end of an axial opening of a cylindrical winding coil is fixed to a rotating shaft, wherein the rotation positioned at the other end of the opening of the rotor winding coil. A small cylindrical coreless motor characterized in that a heat radiating plate having excellent thermal conductivity is integrally or separately attached to a part or the whole area of one side of a resin mold body interposed between a shaft and a winding coil. 2. The small cylindrical coreless motor according to claim 1, wherein said heat radiating plate is made of a copper-based or aluminum-based alloy or carbon-based material having excellent thermal conductivity. 3. An end surface of a heat sink is in contact with an inner peripheral surface of a winding coil and an outer peripheral surface of a rotary shaft with a large fitting area, and is interposed integrally between the two. 3. The small cylindrical coreless motor according to claim 1, wherein: 4. A resin mold body connecting one end of a winding coil and a rotating shaft and a support base integrated with a heat sink have a large number of fins or openings for blowing air. The small cylindrical coreless motor according to claim 1, wherein: 5. A bearing and a bearing house for supporting a rotating shaft on a stator side, and a whole housing for holding and fixing the bearing house are made of a heat-radiating material having high thermal conductivity. A small cylindrical coreless motor according to any one of items 1 to 4. 6. The small cylindrical coreless motor according to claim 1, wherein an uneven cooling fin shape is provided on an outer peripheral surface of the housing. 7. A heat sink member having a concave-convex cooling fin shape having excellent heat conductivity is provided on a part or the entire surface of an exterior surface of a brush stand incorporated in an opening end of a housing. 7. The small cylindrical coreless motor according to any one of items 1 to 6. 8. The small cylindrical coreless motor according to claim 7, wherein the heat sink is made of a copper or aluminum alloy material. 9. A wirelessly operated high-performance gaming toy using the small cylindrical coreless motor according to claim 1 as a driving motor.