JP2004144127A - Reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the assembling performance of a reduction gear. <P>SOLUTION: The reduction gear comprises a sun roller 2 formed coaxially with an input shaft, a planetary roller 3a to be in contact with the outer peripheral face of the sun roller for transmitting the rotation of the input shaft, a planetary pinion gear 3b formed coaxially with the planetary roller, a ring gear 5 non-rotatably fixed to the planetary pinion gear in engagement therewith, and a carrier 8 rotatably supporting the planetary pinion gear and joined to an output shaft. <P>COPYRIGHT: (C)2004,JPO

Description

ここで、ｒ_ＰＲは、遊星ローラ３ａの有効半径であり、ｒ_ＳＲは、太陽ローラ２の有効半径である。Ｚ_ＩＧは、リングギア５の歯数であり、Ｚ_ＰＧは、遊星ピニオンギア３ｂの歯数である。
【００１４】
すなわち、本発明の減速装置においては、速比ｕが、遊星ピニオンギア３ｂとリングギア５の歯数と、太陽ローラ２と遊星ローラ３ａの有効半径から設定されるので、従来技術のように速比ｕの設定が制限されることがない。また、従来技術のように大小の遊星ピニオンの位相を合わせて組み立てる必要がないので、組立性の向上が図れる。
【００１５】
なお、複合ピニオン３を複数個等間隔（例えば４個を９０°間隔）にキャリア８に備えることで、遊星ピニオンギア３ｂが１個当たり分担する荷重を減らすことができ、複合ピニオン３を小型化し、装置全体の小型化を図ることができる。また、出力側に配置された遊星ピニオンギア３ｂとリングギア５からなる遊星歯車機構はサンギアを備えていないので、複数個の遊星ピニオンギア３ｂを配置する場合でも遊星ピニオンギア３ｂとリングギア５との歯数選定に制限がない。
【００１６】
図２は、第２の実施形態の構成を示しており、この実施形態は、第１の実施形態に対して遊星ローラ機構を構成する太陽ローラ２と遊星ローラ３ａの形状を変更したものである。
【００１７】
この実施形態において、遊星ローラ３ａは太陽ローラ２の外周面と接触する外周部３ｄの形状を中央部で外周部３ｄの最大径となるような２つの斜面３ｅ、３ｆから構成する。そしてこの斜面３ｅ、３ｆにそれぞれ対向する円錐ローラ２ａ、２ｂを太陽ローラ２として形成する。入力軸１には、円錐ローラ２ａ、２ｂを所定位置に固定するための突起部１ａが形成され、円錐ローラ２ａ、２ｂを突起部方向に押し付ける与圧調整ナット１０が入力軸１にねじ込まれる。
【００１８】
このようにして、太陽ローラ２から遊星ローラ３ａへの回転伝達に必要な太陽ローラ２の遊星ローラ３ａへの押し付け力は、与圧調整ナット１０の締結力を調整することにより容易に調整することが可能となる。
【００１９】
なお、本実施形態においては、２つの斜面３ｅ、３ｆを用いて説明したが、遊星ピニオンギア３ｂに斜面を望ませる斜面３ｅのみを用いてもよい。すなわち斜面３ｅのみを形成した場合には、前述の実施形態の効果と同様の効果が期待できるとともに、１つの円錐ローラ２ｂと入力軸１の突起部１ａを不要とすることができる。但し、この場合には、スラスト（回転軸）方向への分力が生じるため、後述する第４の実施形態で記載したように遊星ピニオンギア３ｂにはすば歯車を用いることが望ましい。
【００２０】
また、第３の実施形態としての遊星ローラ機構を構成する太陽ローラ２と遊星ローラ３ａの別の接触面の形状は、太陽ローラ２と遊星ローラ３ａの接触面の少なくとも一方にクラウニング等、それぞれの回転軸に対して中央部が凸形状となるようにしたものである。このような形状により、太陽ローラ２と遊星ローラ３ａの接触は中央部で接触されるように構成されるため、片当たりを防止し、接触面の耐久性を向上することができる。
【００２１】
図３は、第４の実施形態の構成を示しており、これは、遊星歯車機構を構成する遊星ピニオンギア３ｂとリングギア５の構成に関するものである。
【００２２】
第２の実施形態においては、遊星ピニオンギア３ｂの外周部に平歯車３ｃを形成し、リングギア５と噛み合うように構成したが、本実施形態においては、遊星ピニオンギア３ｂの外周部に形成される歯車およびそれに噛み合うリングギア５の形状をねじれ角を有するはすば歯車としたことに特徴を有する。
【００２３】
はすば歯車の噛み合いにおいては、遊星ピニオンギア３ｂの回転軸に平行なスラスト力が発生することが知られており、このスラスト力の大きさと向きは、はすば歯車のねじれ角、回転方向、負荷の方向によって決定される。そこで、図３に示すような遊星ローラ３ａ側へのスラスト力を発生させることにより、太陽ローラ２と遊星ローラ３ａの押し付け力が増加し、太陽ローラ２が遊星ローラ２ａを駆動するトラクション力が増加することになる。このスラスト力は負荷に応じて変動するため、負荷に応じた押し付け力を付与することができ、減速装置の伝達効率を向上することができる。
【００２４】
図４は、第５の実施形態を示しており、これは図２に示した第２の実施形態の構成に、遊星ローラ３ａの外周に形成した斜面３ｅ、３ｆに内接するローラリング１１を設けたものである。ローラリング１１を設けることにより、太陽ローラ２と遊星ローラ３ａの押し付け力の反力の一部をローラリング１１が受けることになり、遊星ローラ３ａをピニオンシャフト６に回転自在に支持するためのニードルベアリング７やピニオンシャフト６の耐久性を向上できる。
【００２５】
本発明は、上記した実施形態に限定されるものではなく、本発明の技術的思想の範囲内でさまざまな変更がなしうることは明白である。
【図面の簡単な説明】
【図１】本発明の第１の実施形態を示す構成図である。
【図２】第２の実施形態を示す構成図である。
【図３】第４の実施形態を示す構成図である。
【図４】第５の実施形態を示す構成図である。
【符号の説明】
１　入力軸
２　太陽ローラ
３　複合ピニオンギア
３ａ　遊星ローラ
３ｂ　遊星ピニオンギア
３ｃ　平歯車部
３ｄ　外周部
３ｅ　斜面
３ｆ　斜面
４　ケース
５　リングギア
６　ピニオンシャフト
７　ニードルベアリング
８　キャリア
９　出力軸
１０　与圧調整ナット
１１　ローラリング[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reduction gear, particularly to a reduction gear combining a planetary roller mechanism and a planetary gear mechanism.
[0002]
[Prior art]
Conventionally, as a reduction gear using a plurality of planetary gear mechanisms, the input side is configured with a planetary gear mechanism including a sun gear and a large planetary pinion gear meshing with the sun gear, and the output side is formed coaxially with the large planetary pinion gear. There is a speed reducer configured with a planetary gear mechanism including a small planetary pinion gear and a ring gear that meshes with the small planetary pinion gear (for example, see Patent Document 1). Here, a compound pinion gear composed of large and small planetary pinion gears is rotatably supported by the carrier.
[0003]
In this reduction gear transmission, the gear ratio of the large planetary pinion gear and the small planetary pinion gear is set to be an integer ratio of 2 or more in order to establish engagement with the planetary gear mechanisms on the input and output sides. The structure is such that two pinion gears are assembled in phase.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. Hei 7-119801
[Problems to be solved by the invention]
However, in the prior art, the gear ratio of the large and small planetary pinion gears must be limited, and the phase ratios of these pinion gears must be combined. However, there has been a problem that the assembling is complicated and the manufacturing cost is increased.
[0006]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a speed reducer that does not limit the gear ratio of large and small planetary pinion gears and does not deteriorate the assemblability.
[0007]
[Means for Solving the Problems]
The reduction gear transmission according to the present invention includes a sun roller formed coaxially with the input shaft, a planetary roller which contacts the outer peripheral surface of the sun roller and transmits the rotation of the input shaft, and a planet formed coaxially with the planetary roller. It comprises a pinion gear, a ring gear that meshes with the planet pinion gear and is non-rotatably fixed, and a carrier that rotatably supports the planet pinion gear and is coupled to an output shaft.
[0008]
【The invention's effect】
According to the present invention, the speed ratio of the speed reducer is set from the number of teeth of the planetary pinion gear and the ring gear and the effective radius of the sun roller and the planetary roller. It is not limited by the gear ratio of the planetary pinion gear. Further, since there is no need to assemble the large and small planet pinions in phase, the assemblability can be improved.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a configuration diagram illustrating an example of an embodiment of a reduction gear transmission of the present invention.
[0010]
The input shaft 1 is, for example, a shaft to which the rotational torque of the engine is input, and a sun roller 2 is integrally formed on an outer peripheral portion of the input shaft 1. A compound pinion gear 3 having a rotation axis parallel to the rotation center of the input shaft is provided, and the compound pinion gear 3 includes a planetary roller 3a and a planetary pinion gear 3b. The outer peripheral surface of the sun roller 2 comes into contact with the outer peripheral surface of the planetary roller 3a constituting a part of the compound pinion gear 3, and the rotation of the input shaft 1 is transmitted to the planetary roller 3a. A planetary pinion gear 3b is formed coaxially with the planetary roller 3a, and a spur gear 3c formed on the outer peripheral portion of the planetary pinion gear 3b meshes with a ring gear 5 formed on the inner surface of the case 4. The compound pinion gear 3 composed of the planetary roller 3a and the planetary pinion gear 3b has a hollow shape, and the pinion shaft 6 penetrates through the hollow portion 3d. By disposing the needle bearing 8 between the compound pinion gear 3 and the pinion shaft 6, the compound pinion gear 3 and the pinion shaft 6 are formed to be relatively rotatable. One end of the pinion shaft 6 is fixed to the carrier 8, and the carrier 7 is formed integrally with the output shaft 9.
[0011]
With this configuration, the rotation of the input shaft 1, that is, the rotation of the sun roller 2, is transmitted to the planetary roller 3 a circumscribing the sun roller 2. By the rotation of the planetary roller 3a, the planetary pinion 3b formed integrally with the planetary roller 3a also rotates. At this time, since the ring gear 5 meshing with the planetary pinion gear 3b is fixed to the case 4, the planetary pinion gear 3b rotates along the ring gear 5 while rotating in the opposite direction to the same direction as the sun roller 2. Revolves in the same direction as. Here, the revolution speed of the planetary pinion gear 3 b is the same as the rotation speed of the carrier 7, that is, the output shaft 8 via the pinion shaft 6.
[0012]
Therefore, the rotation speed ratio and the speed ratio u between the input shaft 1 and the output shaft 8 can be calculated by equation (1).
[0013]
(Equation 1)

Here, r _PR is the effective radius of the planetary roller 3a, and r _SR is the effective radius of the sun roller 2. Z _IG is the number of teeth of the ring gear 5, and Z _PG is the number of teeth of the planetary pinion gear 3b.
[0014]
That is, in the reduction gear transmission of the present invention, the speed ratio u is set based on the number of teeth of the planetary pinion gear 3b and the ring gear 5 and the effective radius of the sun roller 2 and the planetary roller 3a. The setting of the ratio u is not restricted. Further, unlike the prior art, it is not necessary to assemble the large and small planetary pinions with the same phase, so that the assemblability can be improved.
[0015]
By providing a plurality of composite pinions 3 at equal intervals (for example, four of them at 90 ° intervals), the load shared by one planetary pinion gear 3b can be reduced, and the size of the composite pinion 3 can be reduced. In addition, the size of the entire apparatus can be reduced. Further, since the planetary gear mechanism composed of the planetary pinion gear 3b and the ring gear 5 arranged on the output side does not have a sun gear, even when a plurality of planetary pinion gears 3b are arranged, the planetary pinion gear 3b and the ring gear 5 There is no restriction on the number of teeth selected.
[0016]
FIG. 2 shows the configuration of the second embodiment. In this embodiment, the shapes of the sun roller 2 and the planetary roller 3a constituting the planetary roller mechanism are changed from those of the first embodiment. .
[0017]
In this embodiment, the planetary roller 3a has a shape of an outer peripheral portion 3d that comes into contact with the outer peripheral surface of the sun roller 2 is formed of two slopes 3e and 3f such that the central portion has the maximum diameter of the outer peripheral portion 3d. The conical rollers 2a and 2b facing the slopes 3e and 3f are formed as sun rollers 2. A projection 1a for fixing the conical rollers 2a, 2b at a predetermined position is formed on the input shaft 1, and a pressurizing adjustment nut 10 for pressing the conical rollers 2a, 2b toward the projection is screwed into the input shaft 1.
[0018]
In this manner, the pressing force of the sun roller 2 against the planetary roller 3a necessary for transmitting the rotation from the sun roller 2 to the planetary roller 3a can be easily adjusted by adjusting the fastening force of the preload adjusting nut 10. Becomes possible.
[0019]
Although the present embodiment has been described using the two slopes 3e and 3f, the planetary pinion gear 3b may use only the slope 3e that makes the slope desired. That is, when only the slope 3e is formed, the same effect as that of the above-described embodiment can be expected, and one conical roller 2b and the projection 1a of the input shaft 1 can be omitted. However, in this case, since a component force is generated in the thrust (rotation axis) direction, it is desirable to use a helical gear for the planetary pinion gear 3b as described in a fourth embodiment described later.
[0020]
Further, the shape of another contact surface between the sun roller 2 and the planetary roller 3a constituting the planetary roller mechanism according to the third embodiment is such that crowning or the like is performed on at least one of the contact surfaces between the sun roller 2 and the planetary roller 3a. The central portion has a convex shape with respect to the rotation axis. With such a shape, the contact between the sun roller 2 and the planetary roller 3a is configured to be brought into contact at the center portion, so that it is possible to prevent the contact of the sun roller 2 and the durability of the contact surface.
[0021]
FIG. 3 shows the configuration of the fourth embodiment, which relates to the configuration of the planetary pinion gear 3 b and the ring gear 5 that constitute the planetary gear mechanism.
[0022]
In the second embodiment, the spur gear 3c is formed on the outer periphery of the planetary pinion gear 3b so as to mesh with the ring gear 5, but in the present embodiment, the spur gear 3c is formed on the outer periphery of the planetary pinion gear 3b. And the ring gear 5 meshing with the helical gear is a helical gear having a torsion angle.
[0023]
It is known that in the meshing of the helical gears, a thrust force parallel to the rotation axis of the planetary pinion gear 3b is generated. The magnitude and direction of the thrust force are determined by the torsion angle of the helical gear and the rotation direction. , Determined by the direction of the load. Therefore, by generating a thrust force on the planetary roller 3a side as shown in FIG. 3, the pressing force between the sun roller 2 and the planetary roller 3a increases, and the traction force for driving the sun roller 2 to drive the planetary roller 2a increases. Will be. Since the thrust force varies according to the load, a pressing force according to the load can be applied, and the transmission efficiency of the reduction gear transmission can be improved.
[0024]
FIG. 4 shows a fifth embodiment in which a roller ring 11 is provided in the configuration of the second embodiment shown in FIG. 2 so as to inscribe the slopes 3e and 3f formed on the outer periphery of the planetary roller 3a. It is something. By providing the roller ring 11, the roller ring 11 receives a part of the reaction force of the pressing force between the sun roller 2 and the planetary roller 3a, and a needle for rotatably supporting the planetary roller 3a on the pinion shaft 6. The durability of the bearing 7 and the pinion shaft 6 can be improved.
[0025]
The present invention is not limited to the embodiments described above, and it is apparent that various modifications can be made within the scope of the technical idea of the present invention.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a configuration diagram showing a second embodiment.
FIG. 3 is a configuration diagram showing a fourth embodiment.
FIG. 4 is a configuration diagram showing a fifth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Input shaft 2 Sun roller 3 Compound pinion gear 3a Planetary roller 3b Planetary pinion gear 3c Spur gear part 3d Outer part 3e Slope 3f Slope 4 Case 5 Ring gear 6 Pinion shaft 7 Needle bearing 8 Carrier 9 Output shaft 10 Pressurizing adjustment nut 11 Roller ring

Claims (6)

A sun roller formed coaxially with the input shaft;
A planetary roller that contacts the outer peripheral surface of the sun roller and transmits the rotation of the input shaft;
A planetary pinion gear formed coaxially with the planetary roller;
A ring gear meshed with the planetary pinion gear and fixed non-rotatably;
And a carrier that rotatably supports the planetary pinion gear and is coupled to an output shaft. The shape of the contact surface of the planetary roller is formed by an inclined surface desired for the planetary pinion gear, and the sun roller is constituted by a conical roller contacting the inclined surface. 2. The reduction gear transmission according to claim 1, further comprising: fastening means for pressing the transmission. 2. The reduction gear transmission according to claim 1, wherein a shape of a contact surface of at least one of the sun roller and the planetary roller is such that a central portion is convex with respect to a rotation axis of the roller. 3. The reduction gear according to any one of claims 1 to 3, wherein the planetary pinion gear and the ring gear are formed by helical gears. The reduction gear according to any one of claims 1 to 4, wherein a roller ring inscribed in the planetary roller is provided. 2. The reduction gear transmission according to claim 1, wherein a plurality of the integrally formed planetary rollers and planetary pinion gears are provided on the carrier at equal intervals.

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