JPH0717878Y2 - Planetary roller type power transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a planetary roller power transmission device.

<Prior Art> Conventionally, a planetary roller type power transmission device is, as is well known,
It is used when acceleration or deceleration is required. Equipped with a plurality of intervening planet rollers, a carrier that is arranged between the outer ring and the sun shaft and rotatably holds each planet roller, and a housing that incorporates the above components and mechanically holds the outer ring. It is a thing. And when the input shaft is connected to the carrier and the output shaft is connected to the sun shaft, it functions as a speed increasing device,
In the opposite case, it functions as a speed reducer.

<Problems to be solved by the invention> By the way, since the planetary roller is press-contacted between the outer ring and the sun shaft, an excessive radial load is applied to the planetary roller and the outer ring and the sun shaft. The pressure is high. Since a conventional planetary roller has a substantially cylindrical shape and is rounded at both ends, a load called an edge load is concentrated on the ends of the planetary roller.

In addition to this, when the temperature rises significantly, the lubricity of the contact portion of the planetary roller with the outer ring and the sun shaft is insufficient, so that the end portion of the planetary roller where the load is likely to concentrate is likely to seize.

The present invention has been made in view of the above circumstances, and an object thereof is to alleviate the load concentration on the end portion of the planetary roller and to eliminate the lack of lubrication under high temperature conditions to improve the life of the planetary roller. I am trying.

<Means for Solving the Problems> In order to achieve such an object, the present invention provides an outer ring,
A sun shaft that is concentrically arranged on the inner circumference of the outer ring, a plurality of planet rollers that are interposed between the outer ring and the sun shaft in a pressure contact state, and a planetary roller that is arranged between the outer ring and the sun shaft. A planetary roller type power transmission device having a rotatably held carrier has the following configuration.

In the planetary roller type power transmission device of the present invention, the end portion of the planetary roller is crowned, and a groove continuous in the circumferential direction is provided in a portion of the outer ring facing the crowning portion of the planetary roller. It is characterized by being used.

A porous member may be housed in the groove, and the lubricating oil may be retained in the porous member. The porous member is preferably housed in the groove so as to protrude from the groove opening, and it is optional to prevent the protruding portion of the porous member from contacting the crowning portion of the planetary roller or to contact it. .

<Operation> Since the end portion of the planetary roller is crowned, the load concentration on the end portion of the planetary roller is suppressed, and the contact pressures of the outer ring and the sun shaft on the planetary roller become substantially equal. Further, since the lubricating oil is stored in the groove provided on the outer ring, the lubricating oil can be satisfactorily supplied to the crowning portion of the planetary roller facing the groove, and the outer ring can be connected to the outer ring by the crowning portion. Lubricating oil is satisfactorily supplied to the pressure contact part through the gap between the planetary rollers, and as a result, lubricity is improved not only in the planetary roller, but also in the outer ring contacting with it and the sun shaft Will be done.

<Embodiment> An embodiment of the present invention will be described below in detail with reference to the drawings.

1 and 2 show an embodiment of the present invention.
In the figure, 1 is a housing, 2 is an outer ring that is press-fitted and fixed to the inner periphery of the housing 1, 3 is a sun shaft that is inserted into the inner periphery of the outer ring 2, and 4 is a first rotating shaft that is formed integrally with the sun shaft 3. Reference numeral 5 denotes a plurality of planetary rollers interposed between the outer ring 2 and the sun shaft 3 in a pressure contact state, and 6 denotes a second planetary roller arranged coaxially with the first rotation shaft 4.
The rotating shaft 7 is a planetary shaft that is planted in a flange 6a formed on the shaft end of the second rotating shaft 6 and extends in the radial direction, and rotatably supports each planetary roller 5. The planetary shaft 7 and the second rotary shaft 6 constitute the carrier described in the claims.

Each of the planetary rollers 5 is crowned at both ends in the axial direction, and has an overall drum-like shape. It should be noted that this crowning includes the case where the planetary roller 5 is crowned by full crowning.

Grooves 8 and 9 which are continuous in the circumferential direction are engraved in a portion of the outer ring 2 that faces the crowning portions 5a and 5b of the planetary roller 5. Rings 10 and 11 made of porous synthetic resin such as sponge and polypropylene are housed in the grooves 8 and 9.
The rings 10 and 11 are set to have a thickness larger than the groove depth of the grooves 8 and 9, and slightly protrude from the groove openings. However, the protruding portions of the rings 10 and 11 are not in contact with the crowning portions 5a and 5b of the planetary roller 5.

Then, the lubricating oil supplied to the contact portion between the planetary roller 5 and the outer ring 2 and the sun shaft 3 is directly fed to the planetary roller 5 and the outer ring 2.
And, an oil film is formed on each circumferential surface of the sun shaft 3, but excess lubricating oil is absorbed in the rings 10 and 11, so that the oil does not flow out to the outside. This lubricating oil is a ring
The coefficient of linear expansion is usually larger than that of the resin material that constitutes
Lubricating oil seeps out from the crowning section 5 of the planetary roller 5.
It will be supplied to a and 5b. Therefore, it is possible to prevent the breakage of the oil film at each contact portion of the planetary roller 5, the outer ring 2 and the sun shaft 3 in a high temperature condition.

By the way, in the above-mentioned embodiment, the example in which the rings 10 and 11 are housed in the grooves 8 and 9 is taken as an example, but a structure in which the rings 10 and 11 are not housed is also included in the present invention. In the above embodiment, the rings 10 and 11 are not in contact with the planetary roller 5, but as shown in FIG.
You may set the thickness of the rings 10 and 11 so that 10 and 11 may contact. In the example shown in FIG. 3, the lubricating oil absorbed in the rings 10 and 11 exudes due to the contact pressure between the rings 10 and 11 and the planet rollers, and is constantly supplied to the planet rollers 5. become. Further, in this example, the positions where the grooves 8 and 9 are formed are set so as to protrude axially to both sides of the both ends of the planetary roller 5, and the rings 10 and 11 located at the protruding portions are used for supply. It is easy to absorb the lubricating oil efficiently.

Needless to say, the present invention is not limited to the planetary roller type power transmission device having the illustrated structure, but can be applied to planetary roller type power transmission devices having various structures.

<Effects of the Invention> As described above, according to the present invention, it is possible to prevent the load concentration on the planetary rollers, to make the load distribution even, and to lubricate the contact portions of the planetary roller, the outer ring and the sun shaft. Since the oil can be efficiently supplied, the seizure life in a normal use state can be significantly extended, and seizure can be reliably avoided even when the temperature rise is particularly remarkable.

[Brief description of drawings]

1 and 2 relate to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a planetary roller type power transmission device, and FIG. 2 is an enlarged view of a portion A of FIG. FIG. 3 is an enlarged cross-sectional view of a main part according to another embodiment of the present invention. 2 ... Outer ring, 3 ... Sun shaft 5 ... Planetary rollers, 5a, 5b ... Crowning part 8, 9 ... Groove, 10, 11 ... Ring (porous member)

Claims (3)

[Scope of utility model registration request] 1. An outer ring, a sun shaft concentrically arranged on the inner circumference of the outer ring, a plurality of planet rollers interposed in pressure contact between the outer ring and the sun shaft, and between the outer ring and the sun shaft. A planetary roller type power transmission device having a carrier for rotatably holding each planetary roller, wherein the end portion of the planetary roller is crowned, and the planetary roller of the planetary roller is attached to the outer ring. A planetary roller type power transmission device characterized in that a groove continuous in the circumferential direction is provided in a portion facing the crowning portion. 2. The planetary roller type power source according to claim 1, wherein a porous member is housed in the groove so as to project from the groove opening so as not to contact the planetary roller. Transmission device. 3. The planetary roller type power transmission device according to claim 1, wherein a porous member is housed in the groove so as to project from the groove opening so as to come into contact with the planetary roller. .