【０００１】
【発明の属する技術分野】
本発明は例えば電動工具に使用される整流子電動機の回転子に関するものである。
【０００２】
【従来の技術】
従来の整流子電動機の回転子２は、図９に示す如く、ラジアル方向外側に開き軸方向に沿って延びるスロットを少なくとも３つ以上有し、回転軸４に装着される回転子コア５、回転子コア５のスロット内に２スロット以上の間隔をもって軸方向に沿って巻回される回転子コイル、回転軸４に装着される冷却ファン６により構成される。製品運転中に回転子２に電流を流すことで回転子コイルに発生した熱を、回転子２と同期して回転する冷却ファン６によって生じた風により放熱させて、回転子２の温度上昇抑制及び過大な温度上昇による焼損を防いでいる。
【０００３】
【発明が解決しようとする課題】
電動工具は仕事効率の向上が要求されているため年々高入力製品が発売されており、回転子２に流す電流は増大している。そのため回転子２の発熱は年々増加しており、回転子２の冷却効率向上は必須である。
【０００４】
従来技術において、回転子２は高速回転物であり風と効率良く接触しているため回転子２のコイルエンドの表面からは十分放熱されており、冷却ファン６によって生じる風の量を増やしてもさらなる冷却効率向上は難しい。そのため、高入力使用時では回転子コイルの発熱により、回転子２が過大な温度上昇により焼損し、製品寿命が短いという問題が生じ易い。
【０００５】
また、回転子コア５及び回転軸４は金属物質であるため熱伝導性能が高いが、通常は製品の電気絶縁性能確保を理由に、回転子コイルと接触する回転子軸４の表面、回転子コア５の端部表面には熱伝導率の低い紙や樹脂などの電気絶縁物７、８が挿入されているため、回転子コイルの熱が伝達されて回転子軸４及び回転子コア５から放熱される冷却効果は小さい。
【０００６】
本発明の目的は、高入力使用時では回転子コイルの発熱により、回転子が過大な温度上昇により焼損し、製品寿命が短くなり易いという問題を解消し、仕事効率向上のために高入力使用時でも温度上昇を抑制して製品寿命を伸ばすこのとできる回転子を提供することである。
【０００７】
【課題を解決するための手段】
上記目的は、回転子のコイルエンドの内側に装着した放熱部材の一部に密着するように回転子コイルを巻回し、前記放熱部材の一部を外気に露出させることにより達成される。
【０００８】
【発明の実施の形態】
以下一実施形態を示す図１を参照して本発明を説明する。
【０００９】
１ａは放熱部材１の円筒部、１ｂは放熱部材の凹凸部、２は回転子、３ａはファン側コイルエンド、３ｂはコンミ側コイルエンド、４は回転子軸、５は回転子コア、６は冷却ファン、７、８は絶縁材である。
【００１０】
円筒部１ａに凹凸部１ｂが設けられた例えばアルミニウム等の放熱部材１において、円筒部１ａを回転子コイルエンドのコア端部そばまで回転軸４に挿入し、円筒部１ａの上から回転子コイルを巻回する。回転子コイルはたるまない程度のテンションを持って巻回されているため、回転子コア５のスロット間で回転子コイルを巻回すると、スロット間の最短距離途中には円筒部１ａがあるため回転子コイルは円筒部１ａの表面になめるように巻回され、円筒部１ａの外周とコイルエンド３ａの内側は良く密着する。さらに、回転子２にはワニスを回転子コイルに含浸させ熱で硬化させるので、円筒部１ａとコイルエンド内部の空気の隙間は少なくなるので、コイルエンド３ａから円筒部１ａには熱が伝達し易い。電動工具に用いられる電動機は一般に、製品の電気絶縁性能確保を理由に回転子コイルと接触する回転子軸４及び回転子コア５端部それぞれの表面には電気絶縁物質である熱伝導率の低い紙及びフェノール樹脂等７、８が装着されているため、回転子コイルの熱が伝達されて回転子軸４及び回転子コア５から放熱される冷却効果は小さい。しかし、放熱部材１に用いる例えばアルミニウムは紙及びフェノール樹脂などの絶縁材料に比べて熱伝導率は１００倍以上大きく熱を伝達し易い。また、前述したように回転軸４及び回転子コア５端部それぞれの表面には絶縁材料７、８が装着されているため、放熱部材１と回転軸４及び回転子コア５は電気的に絶縁されており、コイルエンド３ａの内側を放熱部材１と密着させても、回転子コイルと回転子軸４及び回転子コア５の電気的絶縁は確保されている。
【００１１】
以上のことから、コイルエンド３ａの内側と良く密着した円筒部１ａへは熱が非常に伝達し易く、伝達された熱は凹凸部１ｂから放熱される。従来技術では製品運転中の回転子２は主に回転子コイルの表面から放熱しており、コイルエンド３ａの内側の熱を積極的に放熱する機構を追加した本発明の回転子の冷却効率は飛躍的に向上する。また、放熱部材１の円筒部１ａと凹凸部１ｂは一つの部品で構成されている必要は無く、図３の円筒部１ａ、図４の凹凸部１ｂとで別部品とすることも可能であり、図３の円筒部１ａの外周部と図４の凹凸部１ｂの内周部１ｃで隙間ばめではめ合せ図２の放熱部材１の状態にすれば良く、冷却効率向上のために放熱表面積を広げようと放熱部材の凹凸部が複雑な形状になるとしても、凹凸部が複数の別部品で構成されていれば生産可能である。
【００１２】
図５、図６の他の実施形態では、コイルエンド３ａの内側に密着させる放熱部材９の円筒部９ａにコイルエンド３ａを覆う程度まで軸方向に延びた凹凸部９ｂを設けた放熱部材９を用いている。図２の放熱部材１に比べて、コイルエンド３ａを覆っている部分だけ広がった凹凸部９ｂの放熱表面積によって増加する回転子の冷却性能は、回転子全長を伸ばし製品全長を大きくすることなく確保することができる。
【００１３】
図７、図８の他の実施形態に示すように、外周部近辺に凹凸形状１０ｂを設けた放熱部材１０のスロット１０ｃが回転子コア５のスロットに重なるように放熱部材１０を回転軸４に挿入し、回転子コア５のスロットに巻回するのと同じように放熱部材１０のスロット１０ｃに回転子コイルを巻回しても良い。コイルエンド３ａの内側と放熱部材１０はプレート部１０ａで密着するため、凹凸形状１０ｂで回転子コイルの熱が放熱される。また、放熱部材１０はコンミ側の回転子コア５の端面側に装着しても良く、その場合、コンミ側コイルエンド１０ｂの内側からも放熱することができる。
【００１４】
以上のように、回転子２の冷却向上を目的に装着させる放熱部材は回転子２のコイルエンド３ａ、３ｂどちらの内側に密着させても良く、形状は問わない。
【００１５】
【発明の効果】
以上のように本発明によれば、回転子の冷却性能を飛躍的に向上させ温度上昇を低減させ、仕事効率が向上した高入力で寿命の長い電動機を提供できる。
【図面の簡単な説明】
【図１】本発明回転子の一実施形態を示す一部断面側面図。
【図２】本発明を構成する放熱部材の一実施形態を示す斜視図。
【図３】図２の放熱部材の円筒部を示す斜視図。
【図４】本発明の放熱部材の他の実施形態を示す斜視図。
【図５】本発明回転子の他の実施形態を示す一部断面側面図。
【図６】本発明の放熱部材の他の実施形態を示す斜視図。
【図７】本発明回転子の更に他の実施形態を示す一部断面側面図。
【図８】本発明の放熱部材の更の他の実施形態を示す斜視図。
【図９】従来の回転子の一部断面側面図。
【符号の説明】
１、９、１０は回転子冷却用の放熱部材、２は回転子、３ａはファン側コイルエンド、３ｂはコンミ側コイルエンド、４は回転子軸、５は回転子コア、６は冷却ファン、７、８は絶縁材である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a commutator motor rotor used for a power tool, for example.
[0002]
[Prior art]
As shown in FIG. 9, the rotor 2 of the conventional commutator motor has at least three or more slots that open outward in the radial direction and extend along the axial direction. It is composed of a rotor coil wound in the slot of the child core 5 along the axial direction with an interval of two or more slots, and a cooling fan 6 mounted on the rotating shaft 4. Heat generated in the rotor coil by flowing a current through the rotor 2 during product operation is radiated by wind generated by a cooling fan 6 rotating in synchronization with the rotor 2 to suppress a temperature rise of the rotor 2. In addition, burnout due to excessive temperature rise is prevented.
[0003]
[Problems to be solved by the invention]
Since power tools are required to improve work efficiency, high-input products are released year by year, and the current flowing through the rotor 2 is increasing. Therefore, the heat generation of the rotor 2 is increasing year by year, and it is essential to improve the cooling efficiency of the rotor 2.
[0004]
In the prior art, the rotor 2 is a high-speed rotating object and is in efficient contact with the wind, so that heat is sufficiently radiated from the surface of the coil end of the rotor 2, and even if the amount of wind generated by the cooling fan 6 is increased. It is difficult to further improve the cooling efficiency. Therefore, when a high input is used, the rotor 2 is burned due to an excessive rise in temperature due to heat generated by the rotor coil, and the problem that the product life is short tends to occur.
[0005]
Although the rotor core 5 and the rotating shaft 4 are made of a metal material, they have high heat conduction performance. However, usually, the surface of the rotor shaft 4 that contacts the rotor coil, Since electric insulators 7 and 8 such as paper or resin having low thermal conductivity are inserted into the end surface of the core 5, the heat of the rotor coil is transmitted and the heat is transmitted from the rotor shaft 4 and the rotor core 5. The cooling effect that dissipates heat is small.
[0006]
An object of the present invention is to solve the problem that the rotor is burned due to an excessive temperature rise due to heat generation of the rotor coil at the time of high input use and the product life is easily shortened. It is an object of the present invention to provide a rotor capable of suppressing a rise in temperature and extending a product life even at a time.
[0007]
[Means for Solving the Problems]
The above object is achieved by winding a rotor coil so as to be in close contact with a part of a heat radiating member mounted inside a coil end of the rotor, and exposing a part of the heat radiating member to the outside air.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention will be described below with reference to FIG. 1 showing one embodiment.
[0009]
1a is a cylindrical portion of the heat radiating member 1, 1b is an uneven portion of the heat radiating member, 2 is a rotor, 3a is a fan side coil end, 3b is a combi side coil end, 4 is a rotor shaft, 5 is a rotor core, and 6 is a rotor core. The cooling fans 7, 8 are insulating materials.
[0010]
In the heat-dissipating member 1 made of, for example, aluminum or the like in which the uneven portion 1b is provided on the cylindrical portion 1a, the cylindrical portion 1a is inserted into the rotary shaft 4 to a position near the core end of the rotor coil end, and the rotor coil is placed from above the cylindrical portion 1a. Is wound. Since the rotor coil is wound with a tension that does not sag, when the rotor coil is wound between the slots of the rotor core 5, the rotation is caused by the cylindrical portion 1a in the middle of the shortest distance between the slots. The child coil is wound so as to be licked on the surface of the cylindrical portion 1a, and the outer periphery of the cylindrical portion 1a and the inside of the coil end 3a are in close contact with each other. Furthermore, since the varnish is impregnated into the rotor coil and hardened by heat in the rotor 2, the gap between the cylindrical portion 1a and the air inside the coil end is reduced, so that heat is transmitted from the coil end 3a to the cylindrical portion 1a. easy. In general, the electric motor used in the electric tool has a low heat conductivity as an electric insulating material on the surfaces of the rotor shaft 4 and the end of the rotor core 5 which come into contact with the rotor coil in order to ensure the electric insulation performance of the product. Since paper, phenolic resin and the like 7 and 8 are mounted, the cooling effect that the heat of the rotor coil is transmitted and radiated from the rotor shaft 4 and the rotor core 5 is small. However, for example, aluminum used for the heat radiating member 1 has a thermal conductivity that is 100 times or more larger than that of an insulating material such as paper and phenol resin, and is easy to transmit heat. Further, as described above, since the insulating materials 7 and 8 are attached to the respective surfaces of the end portions of the rotating shaft 4 and the rotor core 5, the heat radiation member 1 is electrically insulated from the rotating shaft 4 and the rotor core 5. Even if the inside of the coil end 3a is brought into close contact with the heat radiating member 1, electrical insulation between the rotor coil and the rotor shaft 4 and the rotor core 5 is ensured.
[0011]
From the above, heat is very easily transmitted to the cylindrical portion 1a which is in close contact with the inside of the coil end 3a, and the transmitted heat is radiated from the uneven portion 1b. In the prior art, the rotor 2 during product operation radiates heat mainly from the surface of the rotor coil, and the cooling efficiency of the rotor of the present invention, which has a mechanism for actively radiating heat inside the coil end 3a, is added. Improve dramatically. Further, the cylindrical portion 1a and the uneven portion 1b of the heat radiating member 1 do not need to be formed as one component, and the cylindrical portion 1a in FIG. 3 and the uneven portion 1b in FIG. The outer peripheral portion of the cylindrical portion 1a in FIG. 3 and the inner peripheral portion 1c of the uneven portion 1b in FIG. Even if the irregularities of the heat radiating member have a complicated shape so as to be spread, production is possible if the irregularities are composed of a plurality of separate parts.
[0012]
In another embodiment of FIGS. 5 and 6, the heat dissipating member 9 in which the cylindrical portion 9 a of the heat dissipating member 9 adhered to the inside of the coil end 3 a is provided with the uneven portion 9 b extending in the axial direction to the extent that the coil end 3 a is covered. Used. As compared with the heat dissipating member 1 of FIG. 2, the cooling performance of the rotor, which is increased by the heat dissipating surface area of the uneven portion 9b which is widened only at the portion covering the coil end 3a, is ensured without increasing the total length of the rotor and increasing the total product length. can do.
[0013]
As shown in other embodiments of FIGS. 7 and 8, the heat radiating member 10 is attached to the rotating shaft 4 such that the slot 10 c of the heat radiating member 10 provided with the uneven shape 10 b near the outer peripheral portion overlaps the slot of the rotor core 5. The rotor coil may be wound around the slot 10c of the heat radiating member 10 in the same manner as inserted and wound around the slot of the rotor core 5. Since the inside of the coil end 3a and the heat dissipation member 10 are in close contact with each other at the plate portion 10a, the heat of the rotor coil is dissipated in the uneven shape 10b. Further, the heat radiating member 10 may be mounted on the end face side of the rotor core 5 on the conical side, and in that case, it is possible to radiate heat also from inside the coil side 10b on the conical side.
[0014]
As described above, the heat dissipating member to be attached for the purpose of improving the cooling of the rotor 2 may be brought into close contact with any one of the coil ends 3a and 3b of the rotor 2, and the shape thereof does not matter.
[0015]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a high-power, long-life motor with improved work efficiency, which significantly improves the cooling performance of the rotor and reduces the temperature rise.
[Brief description of the drawings]
FIG. 1 is a partial sectional side view showing an embodiment of the rotor of the present invention.
FIG. 2 is a perspective view showing one embodiment of a heat radiation member constituting the present invention.
FIG. 3 is a perspective view showing a cylindrical portion of the heat radiation member of FIG. 2;
FIG. 4 is a perspective view showing another embodiment of the heat radiation member of the present invention.
FIG. 5 is a partial sectional side view showing another embodiment of the rotor of the present invention.
FIG. 6 is a perspective view showing another embodiment of the heat radiation member of the present invention.
FIG. 7 is a partially sectional side view showing still another embodiment of the rotor of the present invention.
FIG. 8 is a perspective view showing still another embodiment of the heat radiation member of the present invention.
FIG. 9 is a partial cross-sectional side view of a conventional rotor.
[Explanation of symbols]
1, 9 and 10 are radiator members for cooling the rotor, 2 is the rotor, 3a is the fan side coil end, 3b is the combi side coil end, 4 is the rotor shaft, 5 is the rotor core, 6 is the cooling fan, 7 and 8 are insulating materials.
