JP2004360802A

JP2004360802A - Gear transmission

Info

Publication number: JP2004360802A
Application number: JP2003160461A
Authority: JP
Inventors: Chung-Shing Jang; 重興張
Original assignee: Apex Dynamics Inc
Current assignee: Apex Dynamics Inc
Priority date: 2003-06-05
Filing date: 2003-06-05
Publication date: 2004-12-24

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear transmission capable of reducing the abrasion of an oil seal and elongating its usable life. <P>SOLUTION: This gear transmission comprises a gear rotating means 40 with an input shaft and a gear rotating means 50 with an output shaft driven by the rotation of the gear rotating means with the input shaft in a housing 10 in a state that a disc-shaped first shaft hole 11 and second shaft hole 12 are respectively formed between the input shaft 51 and an inner wall of the housing, and between the output shaft 51 and the inner wall of the housing, and the first and second oil seals 20, 30 are respectively sealed and fitted in the first and second shaft holes in a state that the input shaft and the output shaft can be rotated. At least one of the first oil seal 20 and the second oil seal 30 is slidably kept into contact with the input shaft 41 or the output shaft 51 at their inner peripheral faces 21, 31 through ceramic layers 60, 70. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は歯車変速装置に関する。
【０００２】
【従来の技術】
従来の歯車変速装置に、例えば図１に示すような遊星歯車変速装置がある。この遊星歯車変速装置には、その内壁に内歯歯車１０３を備えたハウジング１内に、入力軸３０１付き歯車回転手段３と、該入力軸付き回転手段３の回転によって駆動される出力軸４０１付き歯車回転手段４とが配設されている。入力軸３０１とハウジング１の内壁との間及び出力軸４０１とハウジング１の内壁との間には、それぞれ円環状の第１の軸孔１０１及び第２の軸孔１０２が形成されている。そして、入力軸付き歯車回転手段３は、該第１の軸孔１０１に回転自在に設けられた入力軸３０１と、入力軸３０１の軸線方向に沿って一体に延伸している太陽歯車３０２とを有する。また、出力軸付き回転手段４は、該第２の軸孔１０２に回転自在に設けられた出力軸４０１と、出力軸４０１の一端に設けられているキャリヤ４０２と、キャリヤ４０２に回転自在に設けられていて内歯歯車１０３と太陽歯車３０２と同時に噛み合っている複数の遊星歯車４０３と、出力軸４０１上に固着されている止め環４０４とを有する。そして、第１の軸孔１０１及び第２の軸孔１０２にそれぞれ、ハウジング１と入力軸３０１及び出力軸４０１との間が水密であるように、それぞれオイルシール２，２ａが嵌入されている。
【０００３】
【発明が解決しようとする課題】
このような遊星歯車変速装置においては、入力軸３０１及び止め環４０４などは合金鋼から構成され、合金鋼の表面粗さＲａは一般に０．４μｍ程度にしか仕上げられないので、実用上は、入力軸３０１または出力軸４０１が３０００ｒｐｍまで回転した場合、オイルシール２は、２０００時間を経過すると、入力軸３０１及び止め環４０４の回転摩擦により摩耗し、破損する欠点があるので、余り高速回転を要する作業に適しない。また、合金鋼で構成された入力軸３０１及び止め環４０のビッカース硬さは一般に４５０〜６００のみにすぎないので、一定の期間使用後は、入力軸３０１及び止め環４０４の表面が摩耗し、表面粗さが損なわれ、オイルシール２の摩耗が速くなり、耐用寿命をも減少させるという欠点もある。
【０００４】
上記に鑑み、本発明の目的は、オイルシールの摩耗を低減し、耐用寿命が伸びる歯車変速装置を提供することにある。
【０００５】
【課題を解決するための手段】
上記目的を達成するため、本発明は、ハウジング内に、入力軸付き歯車回転手段と、該入力軸付き歯車回転手段の回転によって駆動される出力軸付き歯車回転手段とを、それぞれ前記入力軸と前記ハウジングの内壁との間及び前記出力軸と前記ハウジングの内壁との間に、それぞれ円環状の第１の軸孔及び第２の軸孔が形成されるように配設し、該第１及び第２の軸孔内にそれぞれ第１及び第２オイルシールを前記入力軸及び前記出力軸が回転可能な状態に密封嵌入してなる歯車変速装置において、前記第１のオイルシール及び前記第２のオイルシールの少なくとも一つは、その内周面がセラミック層を介して前記入力軸または前記出力軸と滑り接触するように構成してなることを特徴とする歯車変速装置を提供する。
【０００６】
より詳しくは、本発明の歯車変速装置は、第１のオイルシールは、その外周面が前記ハウジングの内壁に一体固着されるように、ハウジングの第１の軸孔に嵌着され、第２のオイルシールは、同様にその外周面が前記ハウジングの内壁に一体固着されるように、ハウジングの第２の軸孔に嵌着され、前記入力軸及び前記出力軸の少なくともいずれかには、前記第１のオイルシールの内周面または前記第２のオイルシールの内周面の少なくともいずれかと滑り接触するセラミック層が設けられているような構成とすることができる一方、本発明の歯車変速装置を、前記第１のオイルシールは、その内周面が前記入力軸に一体となるように、嵌着され、前記第２のオイルシールは、その内周面が前記出力軸に一体となるように、嵌着され、前記第１のオイルシールの外周面及び前記第２のオイルシールの外周面の少なくともいずれかと滑り接触するように、セラミック層が前記ハウジングの内壁に接して設けられている構成とすることもできる。
【０００７】
このように構成された本発明の歯車変速装置は、前記第１のオイルシール及び前記第２のオイルシールの少なくともいずれかが前記セラミックス層を介して前記ハウジングの内壁か前記入力軸及び前記出力軸の少なくともいずれかと、滑り接触されているため、入力軸及び出力軸が回転する時、前記セラミック層の表面粗さを合金鋼より小さくすることができるので、前記第１のオイルシール及び前記第２のオイルシールの少なくともいずれかと前記セラミック層との間の摩擦が小さくなり、オイルシールの摩耗を低減することができる。また、前記セラミック層の硬さも合金鋼より大きなものが選べるので、長期間使用しても、摩耗によってセラミック層の表面粗さを損なうことなく、オイルシールの耐用寿命を伸ばすことができる。
【０００８】
【発明の実施の形態】
以下、図面を参照しながら、本発明の好適な実施形態を説明する。図２に示すのは、本発明の第１の実施形態である。本実施形態においては、遊星歯車変速装置を例として説明するが、他の歯車変速装置にも適用される。図示のように、本実施形態における遊星歯車変速装置は、ハウジング１０内に、入力軸４１付き歯車回転手段４０と、該入力軸４１付き歯車回転手段４０の回転によって駆動される出力軸５１付き歯車回転手段５０とが、ほぼ密閉状に収容されている。入力軸４１と片側に開口するハウジング１０の内壁との間及び出力軸５１と他側に開口するハウジング１０の内壁との間に、それぞれ円環状の第１の軸孔１１及び第２の軸孔１２を形成している。そして、第１の軸孔１１及び第２の軸孔１２には、それぞれ入力軸４１及び出力軸５１が回転自在に第１のオイルシール２０及び第２のオイルシール３０が介装されている。
【０００９】
また、ハウジング１０の内壁に内歯歯車１３が設けられている。出力軸付き回転手段５０は、ハウジング１０外に一端を延伸し、そこに第２の環状軸孔１２を形成している出力軸５１と、ハウジング１０内の出力軸５１の他端に一体連続して形成されたみぞ車状遊星枠５２と、複数の遊星枠５２のみぞ部に回転自在に枢支されて内歯歯車１３と噛み合っている遊星歯車５３とを有する。入力軸付き回転手段４０は、一端がハウジング１０外に伸出し、そこに第１の環状軸孔１１を形成している入力軸４１と、ハウジング１０内の入力軸４１の他端に一体形成されて複数の遊星歯車５３と噛み合っている太陽歯車４２とからなる。そして、入力軸４１は太陽歯車４２との接続部位からハウジング１０の外向方へ順に大径部４１１と、小径部４１２とに形成され、大径部４１１と記小径部４１２との間に肩部４１３が形成されている。また、出力軸５１上の第２の軸孔１２に臨む箇所に、その外周面の片側が面取りされて傾斜面５４１となった止めナット５４が、その傾斜面５４１が内側にくるように固着されている。
【０００１０】
また、第１のオイルシール２０は、その外周面２１がハウジング１０の内壁に固着されるように、第１の軸孔１１に嵌入されている。第２のオイルシール３０は、その外周面３１がハウジング１０の内壁に固着されるように第２の軸孔１２に嵌入されている。そして、入力軸４１及び出力軸５１には、第１のオイルシール２０の内周面２２及び第２のオイルシール３０の内周面３２と水密状に滑り接触するように、それぞれセラミック層６０，７０が接着されている。
【００１１】
本実施形態において、セラミック層６０は焼結によって作製され、嫌気性接着剤で肩部４１３と接するように小径部４１２に接着されている。これにより、セラミック層６０は、第１のオイルシール２０の内環面２２と密接することができる。そして、同じくセラミック層７０は焼結によって作製され、嫌気性接着剤で傾斜面５４１上に接着されている。これにより、セラミック層７０は、第１のオイルシール３０の内環面３２と密接することができる。
【００１２】
また、本実施形態において、セラミック層６０，７０の構成材料は、例えばアルミナや窒化けい素などが用いられるので、セラミック層６０，７０のビッカース硬さは、１７００以上に達することができ、表面粗さも０．２μｍ以下にさせることが可能である。
【００１３】
上記によれば、モータ（図示せず）で入力軸４１を回転させると、回転動力は太陽歯車４２をへて、複数の遊星歯車５３を伝動回転させることにより、出力軸５１を回転させ、回転動力を出力することができる。この時、第１のオイルシール２０の内周面２２及び第２のオイルシール３０の内周面３２はそれぞれセラミック層６０，７０と互いに水密状態を保って滑り接触することができる。
【００１４】
上記のように、本発明の歯車変速装置において、セラミック層６０，７０の表面粗さを０．２μｍ以下にさせ、従来合金鋼構成部材の表面粗さより遥かに小さくさせれば、セラミック層６０，７０と第１のオイルシール２０の内周面２２及び第２のオイルシール３０の内周面３２との間の摩擦による抵抗が従来より小さくなり、第１のオイルシール２０の内周面２２及び第２のオイルシール３０の内周面３２の摩耗を軽減させることができるのみならず、摩擦による熱を回避することができる。本実施形態をテストした結果、実際に、入力軸４１または出力軸５１が６０００ｒｐｍの高速で回転させた場合、第１のオイルシール２０及び第２のオイルシール３０の耐用寿命が５００００時間に達するデータが得られ、第１のオイルシール２０及び第２のオイルシール３０の耐用寿命が従来より長くなり、例えば、印刷や紡織などの高速回転による作業にも適用されることが期待できる。
【００１５】
そして、セラミック層６０，７０のビッカース硬さは１７００以上に達することが可能であり、これは従来の合金鋼部材の硬さより遥かに大であるので、長時間使用しても、セラミック層６０，７０は摩耗によって表面粗さを損なわず、第１のオイルシール２０及び第２のオイルシール３０は容易に摩耗されない。
【００１６】
そして、セラミック層６０，７０の熱伝導率は従来の合金鋼部材より大であるので、セラミック層６０，７０は摩擦による熱を速く放散させ、第１のオイルシール２０及び第２のオイルシール３０の温度を降下させることができる。
【００１７】
また、セラミック層６０，７０が焼結によって成型されることから、一般に多孔質であり、潤滑油を含浸し、それらの第１のオイルシール２０及び第２のオイルシールと接する面を徐々に潤滑する、自己潤滑の効果が期待でき、摩擦による抵抗を更に低減させることが考えられる。
【００１８】
なお、セラミック層６０，７０の化学的性質の安定性や耐食性なども従来の合金鋼部材より優れる。
【００１９】
続いて、図３に示すのは、本発明の第２の実施形態である。本実施形態の上記第１の実施形態と異なる点は、第１のオイルシール２０は、その内周面２２が入力軸４１と一体になるように、入力軸４１に外嵌されており、セラミック層６０が、第１のオイルシール２０の外周面２１と水密に滑り接触するように、ハウジング１０の内壁に接して設けられていることにある。なお、セラミック層６０は、第１のオイルシールの外周面２１及び前記第２のオイルシールの外周面３１の少なくともいずれかと滑り接触するように、ハウジング１０の内壁に設けられればよい。これにより、本実施形態における歯車変速装置も第１の実施形態と同じ効果を達成することができる。
【００２０】
【発明の効果】
上記のように、本発明に係る歯車変速装置は、第１のオイルシール及び第２のオイルシールの少なくとも一つがセラミックス層を介してハウジングの内壁と入力軸及び出力軸の少なくともいずれかと一体状に第１の軸孔及び第２の軸孔に嵌入されているため、入力軸及び出力軸が回転される時、セラミックス層の表面粗さが合金鋼より小であるので、第１のオイルシール及び第２のオイルシールの少なくとも一つとセラミックス層との間の摩擦が小さくなり、オイルシールの摩耗を低減することができる。さらに、セラミックス層のビッカース硬さも合金鋼より大であるので、長期間使用しても、摩耗によってセラミック層の表面粗さを損なうことなく、オイルシールの耐用寿命が長くなる。
【図面の簡単な説明】
【図１】従来の歯車変速装置を示す縦断面図。
【図２】本発明の第１の実施形態にかかる歯車変速装置を示す縦断面図。
【図３】本発明の第２の実施形態にかかる歯車変速装置の要部を示す縦断面図。
【符号の説明】
１，１０・・・ハウジング４，５０・・・出力軸付き歯車回転手段
１０１，１１・・・第１の軸孔４０１，５１・・・出力軸
１０２，１２・・・第２の軸孔４０２，５２・・・キャリヤ
１０３，１３・・・内歯歯車４０３，５３・・・遊星歯車
２・・・オイルシール４０４・・・止め環
２０・・・第１のオイルシール４１１・・・大径部
２１・・・第１のオイルシールの外周面４１２・・・小径部
２２・・・第１のオイルシールの内周面４１３・・・肩部
３０・・・第２のオイルシール５４・・・止めナット
３１・・・第２のオイルシールの外周面５４１・・・傾斜面
３２・・・第２のオイルシールの内周面６０，７０・・・セラミック層
３，４０・・・入力軸付き歯車回転手段
３０１，４１・・・入力軸
３０２，４２・・・太陽歯車[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a gear transmission.
[0002]
[Prior art]
2. Description of the Related Art As a conventional gear transmission, for example, there is a planetary gear transmission as shown in FIG. In this planetary gear transmission, a gear rotating means 3 with an input shaft 301 and an output shaft 401 driven by the rotation of the rotating means 3 with an input shaft are provided in a housing 1 having an internal gear 103 on an inner wall thereof. Gear rotation means 4 is provided. Annular first shaft holes 101 and second shaft holes 102 are formed between the input shaft 301 and the inner wall of the housing 1 and between the output shaft 401 and the inner wall of the housing 1, respectively. Then, the gear rotating means 3 with the input shaft includes an input shaft 301 rotatably provided in the first shaft hole 101 and a sun gear 302 extending integrally along the axial direction of the input shaft 301. Have. The output shaft-equipped rotating means 4 includes an output shaft 401 rotatably provided in the second shaft hole 102, a carrier 402 provided at one end of the output shaft 401, and a rotatably provided carrier 402. It has a plurality of planetary gears 403 that are engaged with the internal gear 103 and the sun gear 302 at the same time, and a retaining ring 404 fixed on the output shaft 401. Oil seals 2 and 2a are fitted into the first shaft hole 101 and the second shaft hole 102, respectively, so that the space between the housing 1 and the input shaft 301 and the output shaft 401 is watertight.
[0003]
[Problems to be solved by the invention]
In such a planetary gear transmission, the input shaft 301, the retaining ring 404, and the like are made of alloy steel, and the surface roughness Ra of the alloy steel is generally only about 0.4 μm. When the shaft 301 or the output shaft 401 rotates up to 3000 rpm, the oil seal 2 has a disadvantage of being worn and damaged by the rotational friction of the input shaft 301 and the retaining ring 404 after 2,000 hours, so that a very high-speed rotation is required. Not suitable for work. In addition, since the Vickers hardness of the input shaft 301 and the retaining ring 40 made of alloy steel is generally only 450 to 600, the surfaces of the input shaft 301 and the retaining ring 404 are worn after a certain period of use, There are also disadvantages in that the surface roughness is impaired, the wear of the oil seal 2 is increased, and the service life is reduced.
[0004]
In view of the above, it is an object of the present invention to provide a gear transmission that reduces the wear of an oil seal and extends its useful life.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides, in a housing, a gear rotating means with an input shaft, and a gear rotating means with an output shaft driven by the rotation of the gear rotating means with an input shaft. An annular first shaft hole and a second shaft hole are disposed between the inner wall of the housing and between the output shaft and the inner wall of the housing, respectively. In a gear transmission having first and second oil seals hermetically fitted into a second shaft hole such that the input shaft and the output shaft are rotatable, the first oil seal and the second oil seal A gear transmission is provided, wherein at least one of the oil seals is configured such that an inner peripheral surface thereof is in sliding contact with the input shaft or the output shaft via a ceramic layer.
[0006]
More specifically, in the gear transmission according to the present invention, the first oil seal is fitted into the first shaft hole of the housing such that the outer peripheral surface is integrally fixed to the inner wall of the housing, and The oil seal is similarly fitted in a second shaft hole of the housing such that an outer peripheral surface thereof is integrally fixed to an inner wall of the housing, and the oil seal is attached to at least one of the input shaft and the output shaft. While a ceramic layer that is in sliding contact with at least one of the inner peripheral surface of the first oil seal and the inner peripheral surface of the second oil seal may be provided, the gear transmission of the present invention may be configured as follows. The first oil seal is fitted so that an inner peripheral surface thereof is integral with the input shaft, and the second oil seal is attached such that an inner peripheral surface thereof is integral with the output shaft. Is fitted, Of to at least one and sliding contact of the outer peripheral surface and the outer peripheral surface of the second oil seal oil seal can also be configured to ceramic layer is provided in contact with the inner wall of the housing.
[0007]
In the gear transmission according to the present invention having the above-described configuration, at least one of the first oil seal and the second oil seal may be connected to the inner wall of the housing or the input shaft and the output shaft via the ceramic layer. Is in sliding contact with at least one of the first oil seal and the second oil seal, since the surface roughness of the ceramic layer can be made smaller than that of alloy steel when the input shaft and the output shaft rotate. The friction between at least one of the oil seals and the ceramic layer is reduced, and the wear of the oil seal can be reduced. In addition, since the hardness of the ceramic layer can be selected to be larger than that of the alloy steel, the service life of the oil seal can be extended even if the ceramic layer is used for a long time without deteriorating the surface roughness of the ceramic layer due to wear.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a first embodiment of the present invention. In the present embodiment, a planetary gear transmission will be described as an example, but the present invention is also applied to other gear transmissions. As shown, the planetary gear transmission according to the present embodiment includes a gear rotating means 40 with an input shaft 41 and a gear with an output shaft 51 driven by rotation of the gear rotating means 40 with an input shaft 41 in a housing 10. The rotating means 50 is housed in a substantially sealed state. An annular first shaft hole 11 and a second shaft hole between the input shaft 41 and the inner wall of the housing 10 opening on one side and between the output shaft 51 and the inner wall of the housing 10 opening on the other side, respectively. 12 are formed. The first shaft hole 11 and the second shaft hole 12 are provided with the first oil seal 20 and the second oil seal 30 so that the input shaft 41 and the output shaft 51 are rotatable, respectively.
[0009]
An internal gear 13 is provided on the inner wall of the housing 10. The rotation means 50 with an output shaft extends one end outside the housing 10, and is integrally connected to the output shaft 51 having the second annular shaft hole 12 formed therein and the other end of the output shaft 51 inside the housing 10. And a plurality of planetary frames 52 rotatably supported by grooves of the plurality of planetary frames 52 and meshing with the internal gear 13. The rotation means 40 with an input shaft is formed integrally with the input shaft 41 having one end extending out of the housing 10 and forming the first annular shaft hole 11 therein and the other end of the input shaft 41 in the housing 10. A plurality of planetary gears 53 and a sun gear 42 meshing with the planetary gears 53. The input shaft 41 is formed in a large-diameter portion 411 and a small-diameter portion 412 in order from the connection portion with the sun gear 42 toward the outside of the housing 10, and a shoulder portion is provided between the large-diameter portion 411 and the small-diameter portion 412. 413 are formed. Further, a lock nut 54 having an outer peripheral surface chamfered on one side to form an inclined surface 541 is fixed to a position facing the second shaft hole 12 on the output shaft 51 such that the inclined surface 541 is on the inner side. ing.
[00010]
The first oil seal 20 is fitted into the first shaft hole 11 such that the outer peripheral surface 21 is fixed to the inner wall of the housing 10. The second oil seal 30 is fitted into the second shaft hole 12 such that the outer peripheral surface 31 is fixed to the inner wall of the housing 10. Then, the input shaft 41 and the output shaft 51 are brought into water-tight sliding contact with the inner peripheral surface 22 of the first oil seal 20 and the inner peripheral surface 32 of the second oil seal 30, respectively. 70 are adhered.
[0011]
In the present embodiment, the ceramic layer 60 is made by sintering, and is adhered to the small diameter portion 412 so as to be in contact with the shoulder portion 413 with an anaerobic adhesive. Thereby, the ceramic layer 60 can be in close contact with the inner ring surface 22 of the first oil seal 20. The ceramic layer 70 is also manufactured by sintering, and is bonded on the inclined surface 541 with an anaerobic adhesive. Thereby, the ceramic layer 70 can be in close contact with the inner ring surface 32 of the first oil seal 30.
[0012]
Further, in the present embodiment, for example, alumina or silicon nitride is used as a constituent material of the ceramic layers 60 and 70, so that the Vickers hardness of the ceramic layers 60 and 70 can reach 1700 or more, and the surface roughness can be increased. It is also possible to make it less than 0.2 μm.
[0013]
According to the above, when the input shaft 41 is rotated by the motor (not shown), the rotation power is transmitted to the sun gear 42 and the plurality of planetary gears 53 is transmitted and rotated, thereby rotating the output shaft 51 and rotating. Power can be output. At this time, the inner peripheral surface 22 of the first oil seal 20 and the inner peripheral surface 32 of the second oil seal 30 can make sliding contact with the ceramic layers 60 and 70, respectively, while maintaining a watertight state.
[0014]
As described above, in the gear transmission according to the present invention, if the surface roughness of the ceramic layers 60 and 70 is set to 0.2 μm or less and is much smaller than the surface roughness of the conventional alloy steel component, The frictional resistance between the inner peripheral surface 70 of the first oil seal 20 and the inner peripheral surface 32 of the second oil seal 30 and the inner peripheral surface 32 of the second oil seal 30 is smaller than in the prior art. Not only can the wear of the inner peripheral surface 32 of the second oil seal 30 be reduced, but also heat due to friction can be avoided. As a result of testing this embodiment, when the input shaft 41 or the output shaft 51 is actually rotated at a high speed of 6000 rpm, the data that the service life of the first oil seal 20 and the second oil seal 30 reaches 50,000 hours is obtained. Is obtained, the service life of the first oil seal 20 and the second oil seal 30 becomes longer than before, and it can be expected that the first oil seal 20 and the second oil seal 30 are applied to high-speed operations such as printing and textiles.
[0015]
The Vickers hardness of the ceramic layers 60 and 70 can reach 1700 or more, which is far greater than the hardness of a conventional alloy steel member. 70 does not impair the surface roughness due to abrasion, and the first oil seal 20 and the second oil seal 30 are not easily abraded.
[0016]
Since the thermal conductivity of the ceramic layers 60 and 70 is greater than that of the conventional alloy steel member, the ceramic layers 60 and 70 quickly dissipate the heat due to friction, and the first oil seal 20 and the second oil seal 30. Temperature can be lowered.
[0017]
Further, since the ceramic layers 60 and 70 are formed by sintering, they are generally porous and impregnated with a lubricating oil, and the surfaces of the ceramic layers 60 and 70 that are in contact with the first oil seal 20 and the second oil seal are gradually lubricated. In addition, the effect of self-lubrication can be expected, and it is conceivable to further reduce the resistance due to friction.
[0018]
The stability of the chemical properties of the ceramic layers 60 and 70 and the corrosion resistance are also superior to those of the conventional alloy steel members.
[0019]
Subsequently, FIG. 3 shows a second embodiment of the present invention. The difference of the present embodiment from the first embodiment is that the first oil seal 20 is externally fitted to the input shaft 41 such that the inner peripheral surface 22 is integral with the input shaft 41, and the first oil seal 20 is made of ceramic. The layer 60 is provided in contact with the inner wall of the housing 10 so as to make water-tight sliding contact with the outer peripheral surface 21 of the first oil seal 20. The ceramic layer 60 may be provided on the inner wall of the housing 10 so as to make sliding contact with at least one of the outer peripheral surface 21 of the first oil seal and the outer peripheral surface 31 of the second oil seal. Accordingly, the gear transmission according to the present embodiment can also achieve the same effects as those of the first embodiment.
[0020]
【The invention's effect】
As described above, in the gear transmission according to the present invention, at least one of the first oil seal and the second oil seal is integrally formed with the inner wall of the housing and at least one of the input shaft and the output shaft via the ceramic layer. When the input shaft and the output shaft are rotated, the surface roughness of the ceramic layer is smaller than that of the alloy steel when the input shaft and the output shaft are rotated. Friction between at least one of the second oil seals and the ceramic layer is reduced, and wear of the oil seals can be reduced. Furthermore, since the Vickers hardness of the ceramic layer is larger than that of the alloy steel, even if the ceramic layer is used for a long period of time, the service life of the oil seal is extended without impairing the surface roughness of the ceramic layer due to wear.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a conventional gear transmission.
FIG. 2 is a longitudinal sectional view showing the gear transmission according to the first embodiment of the present invention.
FIG. 3 is a longitudinal sectional view showing a main part of a gear transmission according to a second embodiment of the present invention.
[Explanation of symbols]
1, 10 ... housing 4, 50 ... gear rotating means with output shaft 101, 11 ... first shaft hole 401, 51 ... output shaft 102, 12 ... second shaft hole 402 , 52 ... Carriers 103, 13 ... Internal gear 403, 53 ... Planetary gear 2 ... Oil seal 404 ... Stop ring 20 ... First oil seal 411 ... Large diameter Part 21: outer peripheral surface of first oil seal 412: small-diameter part 22: inner peripheral surface of first oil seal 413: shoulder 30: second oil seal 54 · Lock nut 31 ··· Outer peripheral surface of the second oil seal 541 · · · Sloped surface 32 · · · Inner peripheral surface of the second oil seal 60, 70 ... Ceramic layer 3, 40 ... Input shaft Gear rotating means 301, 41 ... input shafts 302, 42 ... sun teeth

Claims

In the housing, a gear rotating means with an input shaft and a gear rotating means with an output shaft driven by rotation of the gear rotating means with the input shaft are respectively provided between the input shaft and the inner wall of the housing and the output shaft. And a first shaft hole and a second shaft hole having an annular shape are formed between the first shaft hole and the second shaft hole, respectively, and the first and second shaft holes are respectively formed in the first and second shaft holes. (2) A gear transmission in which an oil seal is hermetically fitted so that the input shaft and the output shaft can rotate.
The first oil seal is fitted into the first shaft hole of the housing such that an outer peripheral surface thereof is integrally fixed to an inner wall of the housing,
The second oil seal is fitted into the second shaft hole of the housing such that an outer peripheral surface thereof is integrally fixed to an inner wall of the housing,
At least one of the input shaft and the output shaft is provided with a ceramic layer that is in sliding contact with at least one of the inner peripheral surface of the first oil seal and the inner peripheral surface of the second oil seal. A gear transmission characterized by the above-mentioned.

In the housing, a gear rotating means with an input shaft and a gear rotating means with an output shaft driven by rotation of the gear rotating means with the input shaft are respectively provided between the input shaft and the inner wall of the housing and the output shaft. And a first shaft hole and a second shaft hole having an annular shape are formed between the first shaft hole and the second shaft hole, respectively, and the first and second shaft holes are respectively formed in the first and second shaft holes. (2) A gear transmission in which an oil seal is hermetically fitted so that the input shaft and the output shaft can rotate.
The first oil seal is fitted so that an inner peripheral surface thereof is integrated with the input shaft,
The second oil seal is fitted so that an inner peripheral surface thereof is integrated with the output shaft,
A gear layer, wherein a ceramic layer is provided in contact with an inner wall of the housing so as to make sliding contact with at least one of an outer peripheral surface of the first oil seal and an outer peripheral surface of the second oil seal. apparatus.

The input shaft is formed in a large-diameter portion and a small-diameter portion in the outward direction of the housing, a shoulder is formed between the large-diameter portion and the small-diameter portion, and the ceramic layer is in contact with the shoulder. The gear transmission according to claim 1, wherein the gear transmission is provided at the small diameter portion.

At a position facing the second shaft hole on the output shaft, a lock nut having one side of an outer peripheral surface chamfered to be an inclined surface is fixed so that the inclined surface is inward, and the ceramics The gear transmission according to claim 1, wherein a layer is formed on the inclined surface.

3. The gear transmission according to claim 1, wherein the Vickers hardness of the ceramic layer is 1700 or more, and the surface roughness of the ceramic layer is 0.2 μm or less. 4.

An internal gear is provided on an inner wall of the housing,
The output shaft-equipped rotating means is formed continuously with the output shaft extending at one end outside the housing and forming a second annular shaft hole therein, and the other end of the output shaft in the housing. Having a grooved wheel-shaped planetary frame, and a planetary gear rotatably supported by the plurality of groove portions of the planetary frame and meshing with the internal gear,
3. The gear transmission according to claim 1, wherein the rotation unit with an input shaft includes a sun gear integrally formed with one end of the input shaft and meshing with the plurality of planetary gears. 4.

In the housing, a gear rotating means with an input shaft and a gear rotating means with an output shaft driven by rotation of the gear rotating means with the input shaft are respectively provided between the input shaft and the inner wall of the housing and the output shaft. And a first shaft hole and a second shaft hole having an annular shape are formed between the first shaft hole and the second shaft hole, respectively, and the first and second shaft holes are respectively formed in the first and second shaft holes. (2) In a gear transmission in which the oil seal is sealingly fitted so that the input shaft and the output shaft are rotatable, at least one of the first oil seal and the second oil seal has an inner peripheral surface thereof. A gear transmission, wherein the gear transmission is configured to make sliding contact with the input shaft or the output shaft via a ceramic layer.