JPH08247240A - Planetary roller type friction transmitting device - Google Patents

Abstract

PURPOSE: To omit the working of the inner surface of a ring roller and the working of a crown. CONSTITUTION: The working of the inner surface to reduce the contact width (b) between a ring roller 3 and a planetary roller 2 and the working of a crown to equalize the bearing pressure distribution in the axial direction with the planetary roller after the shrink fitting of the ring roller are omitted and the weight of the ring roller is reduced by arranging in parallel the ring roller 3 and two ring rollers 7 of I-shaped section in the axial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary roller friction transmission applied to a power transmission system, for example, a planetary roller friction transmission suitable for a speed reducer or a speed increaser in a power transmission system for wind turbine generators. Regarding the device. It can also be applied to power transmission systems of helicopters and underwater robot propulsion devices, in addition to speed reducers and speed increasers for wind turbine generators.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 4 and 5, a planetary roller type friction transmission device has been known.

That is, in FIGS. 4 and 5, reference numeral 1 denotes a sun roller having an input shaft 1a as a first shaft, and a planet roller pin 6 planted in a carrier 5 is provided on the outer peripheral surface of the sun roller 1. A plurality of planet rollers 2 having the same diameter are arranged so as to be loosely fitted, and a ring roller 3 for pressing each planet roller 2 against the outer peripheral surface of the sun roller 1 is arranged. An output shaft 5a as a second shaft is attached to the carrier 5 concentrically with the input shaft 1a.

Then, by applying a normal force P between the sun roller 1 and the planetary roller 2 and between the planetary roller 2 and the ring roller 3, a tangential force F is generated between the respective rollers, and this tangential force F is generated. A transmission torque obtained by multiplying the roller radius at the tangential force generation position is obtained.

The tangential force F is proportional to the traction coefficient between the rollers. As a traction coefficient,
If you use a dedicated lubricating oil, it can be increased up to about 0.1. Normally, a plurality of planetary rollers 2 (generally three or four) are arranged in the circumferential direction when the deceleration or speedup ratio is determined. It will be limited because of this. The normal force P is
Since the method of shrink-fitting the ring roller 3 is structurally simple and a large normal force can be obtained, it is widely and generally used.

Further, a pin 4 for preventing rotation, which is planted in the casing 10, is attached to the end surface of the ring roller 3 so that the ring roller is not rotated by the traction force.

By the way, the ring roller 3 and the planetary roller 2
Since and have a concave contact, the planetary roller 2 and the sun roller 1 have a convex contact. Therefore, when a normal force due to shrinkage fitting is applied, compared with the contact surface pressure between the planetary roller 2 and the sun roller 1. The surface pressure between the ring roller 3 and the planetary roller 2 is reduced to about 1/2, and the traction coefficient in the same portion is greatly reduced.

Therefore, in order to avoid this, a method is adopted in which the inner surface of the ring roller 3 is processed to shorten the contact width b between the ring roller 3 and the planetary roller 2. However, from the viewpoint of contact stability, it is set at two locations in the axial direction.

[0009]

By the way, in the conventional apparatus, in order to prevent the contact fatigue life of the rollers from being shortened due to the locally high surface pressure, the crowning ring is used to make the axial contact surface pressure between the rollers uniform.

However, the crowning process on the inner surface side of the cylindrical ring roller requires a complicated crowning shape and a high accuracy in consideration of the influence of the deformation of the non-contact portion,
This is an extremely difficult process, and at present, it is being carried out while confirming and correcting it one by one with a shape measuring instrument, which requires a large number of man-hours and raises the cost. The present invention seeks to solve such problems.

[0011]

In order to achieve the above object, a planetary roller type friction transmission device of the present invention is provided with a sun roller having a first shaft attached thereto and a pressure roller arranged on an outer peripheral surface of the sun roller. A plurality of planetary rollers having the same diameter, a second shaft concentric with the first shaft, and a plurality of planetary roller pins rotatably supporting the planetary rollers with respect to the first shaft. A plurality of I-shaped cross-section ring rollers each having a carrier arranged in a loose fit shape and a ring roller shrink-fitted on the outer periphery of each planetary roller, the ring roller having an I-shaped cross-section. It is characterized by being arranged in the axial direction of the first shaft and the second shaft.

Further, in the planetary roller type friction transmission device of the present invention, the I-shaped section ring roller serves as an inner flange for rolling contact with the outer flange and the respective planet rollers, and a connecting member for connecting the outer flange and the inner flange. A web portion, and the inner flange forms the axial wall thickness distribution shapes of the first shaft and the second shaft in the axial direction on the contact surface of the ring roller with the planetary roller after shrink fitting. It is characterized in that the surface pressure distribution is formed to be substantially uniform.

Further, in the planetary roller type friction transmission device of the present invention, the I-shaped section ring roller serves as an outer flange and an inner flange in contact with each planet roller, and a connecting member for connecting the outer flange and the inner flange. A web portion, the web portion is formed of two webs, and the outer end portions of the two webs are closely adhered to the outer flange while being joined to each other. It is characterized in that each inner end portion is formed in such a shape that it is joined to the inner flange so as to be separated from each other so as to form a space between both webs.

Furthermore, in the planetary roller type friction transmission device of the present invention, the I-shaped ring roller is used as an outer flange and an inner flange in contact with each planet roller, and as a connecting member between the outer flange and the inner flange. The two webs are formed so that the two webs are substantially parallel to each other and form a space between the two webs. Each of the outer end portions and the inner end portions of is formed into a shape in which the outer flange and the inner flange are respectively joined.

[0015]

In the planetary roller type friction transmission device of the present invention described above, the ring roller is an I-shaped cross-section ring roller having an I-shaped cross section, so that the axial surface pressure between the shrink-fitted planetary roller and the planetary roller is reduced. The distribution can be made as uniform as during crowning. This is because the axial wall thickness distribution (rigidity) of the flange corresponds to the shrink fitting surface pressure.
By setting the I-shaped dimension and shape with an appropriate wall thickness distribution, the crowning process can be eliminated.

Further, the I-shaped cross section can be remarkably reduced in weight as compared with the conventional rectangular cross section if the rigidity is the same. Also, by arranging a plurality of the rings in the axial direction, it is possible to eliminate the inner surface processing for shortening the contact width and to maintain the contact stability almost equal to that of the conventional device.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a main part of a planetary roller friction transmission device as a first embodiment thereof, and FIG. 2 is a second embodiment thereof. FIG. 3 is a vertical sectional view of a ring roller of a planetary roller type friction transmission device, and FIG. 3 is a vertical sectional view of a ring roller of a planetary roller type friction transmission device as a third embodiment thereof. In addition,
1-3, the same reference numerals as those in FIGS. 4 and 5 indicate substantially the same members.

First, referring to FIG. 1, the first embodiment will be described. In the planetary roller type friction transmission of the first embodiment, the sun roller (not shown) and the outer periphery of the sun roller are also the same as in the conventional device described above. An input shaft serving as a first shaft for the sun roller, which is composed of a plurality of planet rollers 2 having the same diameter and rotatably fitted on the surface by a carrier, and a ring roller 3 shrink-fitted on the outside of the plurality of planet rollers 2. , The planetary roller 2 is loosely fitted to a carrier (not shown) by a planet pin (not shown), and an output shaft (not shown) is further attached to the carrier. Further, the carrier is arranged so as to be loosely fitted to the first shaft.

In this first embodiment, the ring roller 3 is
The ring roller 7 has an I-shaped cross section and a plurality of (two) I-shaped cross sections are arranged in the axial direction (direction parallel to the input shaft and the output shaft). Each I-shaped ring roller 7 has an outer flange 7a and an inner flange 7b, and both flanges 7a and 7b.
It has a web portion as a connecting member for connecting a and 7b.

Here, the inner flange 7b has an axial direction (see FIG. 1).
(In the left-right direction) is formed in an inclined wall thickness distribution shape in which the central portion is thick and both end portions are thin. The web portion is composed of a thin plate-shaped web 7c. Further, the two I-shaped section ring rollers 7 are positioned with respect to each other by a connecting pin 8, and the detent pin 4 planted in the casing 10 is attached to the end surface of one of the I-shaped section ring rollers 7. . Reference numeral b in FIG. 1 indicates a contact width between the I-shaped section ring roller 7 and the planetary roller 2.

By forming the cross section of the ring roller into the above-mentioned shape, the axial surface pressure distribution with the planetary roller after shrink fitting the ring roller is made uniform to the same extent as when crowning is applied. can do. This is because the axial thickness distribution (rigidity) of the inner flange 7b of the I-shaped ring roller 7 corresponds to the shrink fitting surface pressure.

That is, with respect to the inner flange 7b of the I-shaped ring roller 7, the crowning is performed by forming the axial wall thickness distribution in advance into an appropriate wall thickness distribution shape in consideration of the shrink fitting surface pressure. Processing can be eliminated.
In addition, since the outer flange 7a and the lower side flange 7b are connected by a thin plate-shaped web 7c, a significant weight can be obtained under the same rigidity as compared with the conventional rectangular cross section. It can be reduced.

Further, by arranging a plurality of I-shaped cross-section rings 7 side by side in the axial direction, contact stability of about the same level as that of the conventional device can be achieved while eliminating inner surface processing for shortening the contact width (contact width with the planetary roller 2). The sex can be maintained.

In the second embodiment shown in FIG. 2, the I-shaped ring roller 7 has a thin plate-shaped web 7 having two web portions.
c and 7c are joined to each other by closely contacting their outer ends to the inner surface of the outer flange 7a and joining the inner ends of the c and 7c to the inner surface of the inner flange 7b, and between the webs 7c. It is formed in a shape that is joined to.

And by having such a shape,
In the second embodiment, in addition to the effects of the first embodiment described above, the axial rigidity of the I-shaped ring roller 7 can be changed by forming the void 9.
This has the advantage that the contact pressure distribution on the planetary roller 2 can be made more uniform.

In the third embodiment of FIG. 3, in the I-shaped section ring roller 7, the web portion 7 has two thin plate-like web portions.
c and 7c are formed substantially parallel to each other and their outer and inner ends are joined to the outer flange 7a and the inner flange 7b, respectively, so that a space 9 is formed between the webs 7c and 7c. Has been done.

The third embodiment having such a shape can obtain substantially the same advantages as those of the second embodiment. The second axis is the input axis and the first
Power transmission with the shaft as the output shaft is also possible.

[0028]

As described in detail above, according to the planetary roller type friction transmission device of the present invention, the following effects and advantages are obtained. (1) It is possible to eliminate the inner surface processing for shortening the contact width between the ring roller and the planetary roller and the crowning processing for uniforming the axial surface pressure distribution with the planetary roller after shrink fitting the ring roller. As a result, the man-hours can be significantly reduced. (2) The weight of the ring roller can be reduced. (3) Due to the reasons (1) and (2) above, the cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of a planetary roller type friction transmission device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a ring roller of a planetary roller type friction transmission device as a second embodiment.

FIG. 3 is a longitudinal sectional view of a ring roller of a planetary roller type friction transmission device as a third embodiment.

FIG. 4 is a longitudinal sectional view of a conventional planetary roller friction transmission device.

5 is a sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 sun roller 1a input shaft as the first shaft 2 planetary roller 3 ring roller 4 non-rotating pin 5 carrier 5a output shaft as the second shaft 6 planetary roller pin 7 I-shaped ring roller 7a outer flange 7b inner flange 7c web 8 connection Pin 9 Vacancy 10 Casing

Claims (4)

[Claims] 1. A planetary roller friction transmission device comprising: a sun roller having a first shaft attached thereto; a plurality of planetary rollers having the same diameter, which are pressed and arranged on an outer peripheral surface of the sun roller; On the other hand, a carrier provided with a concentric second shaft and a plurality of planet roller pins that rotatably support the planet rollers, the carrier being arranged in a loose fit with respect to the first shaft, and the planet rollers. And a ring roller shrink-fitted on the outer periphery of the ring roller, the ring roller having an I-shaped cross section.
A planetary roller type friction transmission device comprising a plurality of die section ring rollers arranged in the axial direction of the first shaft and the second shaft. 2. The I-shaped cross-section ring roller comprises an outer flange, an inner flange rollingly contacting each planetary roller, and a web portion as a connecting member between the outer flange and the inner flange, wherein the inner flange comprises: The axial wall thickness distribution shape of the first shaft and the second shaft is made to be a shape that can substantially uniformize the axial surface pressure distribution on the contact surface of the ring roller with the planetary roller after shrink fitting. A planetary roller type friction transmission characterized by being formed. 3. The I-shaped cross-section ring roller comprises an outer flange, an inner flange in contact with each planetary roller, and a web portion as a connecting member between the outer flange and the inner flange. Formed from a single sheet of web
The outer ends of the webs are intimately joined to the outer flange while the inner ends of the two webs are separated from the inner flange to form a void between the webs. The planetary roller type friction transmission device according to claim 1 or 2, wherein the planetary roller type friction transmission device is formed in such a joined shape. 4. The I-shaped cross-section ring roller comprises an outer flange, an inner flange in contact with each of the planetary rollers, and a web portion as a connecting member between the outer flange and the inner flange. Formed from a single sheet of web
The outer and inner ends of the two webs are joined to the outer and inner flanges, respectively, so that the webs are substantially parallel to each other and form a cavity between the webs. The planetary roller type friction transmission device according to claim 1, wherein the planetary roller type friction transmission device is formed in a shape.