JPS6353358A - Power transmission device - Google Patents

Abstract

PURPOSE:To hold down loss torque to the minimum and eliminate jarring reaction at the time of reversing by providing a plurality of angular ball bearings which are axially interposed between each of planetary shafts and each of planetary rollers and resiliently urging members for applying pre-pressure to the respective angular ball bearings. CONSTITUTION:There are provided a sun roller 40 connected to the first rotary shaft 10, a fixed ring 41 concentrically disposed in the outer periphery of the roller, a plurality of cylindrical planetary rollers 42 interposed in the pressed state between the roller and the ring and planetary shafts 43 which are concentrically inserted in the rollers and connected to the second rotary shaft 20. A plurality of angular ball bearings 50a, 50b are axially interposed between each of planetary shafts 43 and each of planetary roller 42 and there are provided wave washers 60 for applying pre-pressure to the respective ball bearings. Accordingly, the pre-pressure eliminates the internal clearance of the angular ball bearings 50a, 50b, which results in eliminating the clearance between the planetary rollers 42 and the planetary shafts 43, so that loss torque can be held down to the minimum and jarring reaction at the time of reversing power transmission direction can be avoided.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention transmits power between two rotating shafts using a transmission mechanism in which a planetary roller is interposed in pressure contact between a fixed wheel and a sun roller. This invention relates to a power transmission device that transmits data by decelerating or increasing speed.

<Prior art> Figures 5 and 6 show this type of conventional power transmission device.
This will be explained with reference to the figures.

In these figures, reference numeral 1 denotes a cylindrical sun roller, which is fixed to the shaft end of the first rotating shaft 2. As shown in FIG.

A housing 3 that covers the outer periphery of the first rotating shaft 2 includes a fixed ring 4.
is fixed concentrically with the sun roller 1.

A plurality of cylindrical planetary rollers 5 are interposed between the fixed ring 4 and the sun roller 1 in a pressed state. One planetary shaft 6 is loosely fitted into the hollow portion 5a of each of the planetary rollers 5 via a floating bushing 6a. The planetary shaft 6 is integrally formed with #h of the second rotating shaft 7.

In addition, the code|symbol 8 is a rolling bearing which supports the 2nd rotating shaft 7.

Next, the operation will be explained.

When the first rotating shaft 2 is used as an input shaft and the second rotating shaft 7 is used as an output shaft, the power from the first rotating shaft 2 is transferred from the sun roller 1 to the second rotating shaft via the planetary roller 5 and the free x sleeve 6. 7 and is transmitted. At this time, the second rotation shaft 7 is in the same direction as the rotation direction of the first rotation shaft 2.

Conversely, when the second rotating shaft 7 is used as the input shaft and the first rotating shaft 2 is used as the output shaft, the power from the second rotating shaft 7 is transmitted to the first rotating shaft 2 via the planetary shaft 6 and the planetary roller 5. The speed is increased and transmitted.

However, the power transmission device having such a configuration has the following problems.

Since the planetary shaft 6 of the second rotating shaft 7 is loosely fitted to the planetary roller 5, there is a gap between the planetary roller 5 and the planetary shaft 6, which corresponds to the backlash of a gear, for example. are doing. This gap not only causes an increase in torque loss during power transmission, but also causes rattling when the direction of power transmission is reversed.

In order to solve these problems, an improved power transmission WW as shown in FIG. 7 has been proposed. In this figure, the same reference numerals as in FIG. 5 refer to the same parts or corresponding parts.

The configuration different from the conventional example described above is that a roller bearing 9 is interposed in place of the floating tube or juro a interposed between the planetary roller 5 and the planetary shaft 6. In some cases, the roller bearing 9 is a deep groove ball bearing.

<Problems to be Solved by the Invention> Even in such improved examples, the above-mentioned problems cannot be satisfactorily solved. That is, the roller bearing 9 has an internal gap that cannot be removed due to its structure, and this internal gap corresponds to the bank lash of gears and the like.

The present invention was made in view of the above circumstances, and it eliminates the gap formed between the planetary roller and the planetary shaft.
The purpose is to minimize torque loss and eliminate rattling when the power transmission direction is reversed.

Means for Solving the Problems> In order to achieve the above object, the present invention has the following configuration.

That is, the power transmission device according to the present invention includes a sun roller connected to a first rotating shaft, a fixed ring arranged concentrically around the outer periphery of the sun roller, and between the fixed ring and the sun roller. A plurality of cylindrical planetary rollers interposed in a press-contact state, a T1 star shaft inserted concentrically into each of the planetary rollers and connected to a second rotating shaft, each of the planetary shafts and each of the planetary planets. It is configured to include a plurality of angular ball bearings interposed in the axial direction between the rollers and resilient members that apply preload to each of the angular ball bearings.

<Effect> The effects of the configuration of the present invention are as follows.

A plurality of angular ball bearings interposed in the axial direction between each planetary roller and each planetary shaft are preloaded with a resilient member. This preload eliminates internal gaps in each of the angular ball bearings.

That is, there is no gap between the planetary shaft and the planetary roller, which corresponds to the backlash of the gear.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

1 and 2 show one embodiment of the invention.

In these figures, reference numeral 10 indicates a first rotating shaft, and reference numeral 20
30 is a housing, 40 is a sun roller, 41 is a fixed ring, 42 is a planetary roller, 43 is a planetary shaft, 50a is a first angular ball bearing, 50b is a second In the angular contact ball bearings, reference numeral 60 indicates a wave washer as a resilient member.

The first rotating shaft 10 and the second rotating shaft 20 are arranged coaxially and are arranged within the housing 30. A sun roller 40 is integrally formed at the shaft end of the first rotating shaft 10 . A fixed ring 41 is fixed to the inner peripheral surface of the housing 30 concentrically with the sun roller 4o.

In this embodiment, four cylindrical planetary rollers 42 are interposed between the sun roller 40 and the fixed ring 41 in a press-contact state. These planetary rollers 42 are arranged at equal intervals in the circumferential direction.

A planetary shaft 43 is inserted concentrically inside each planetary roller 42, and two angular ball bearings 50a, 50b are provided between the planetary roller 42 and the planetary shaft 43 at both ends of the planetary roller 42. is mediated. One is a first angular ball bearing 50a, and the other is a second angular ball bearing 50b.

The first angular contact ball bearing 50a and the second angular contact ball bearing 5
0b is the back surface 51a of each outer ring 51a, 51b.

, 51b+ are arranged to face each other, and the outer ring 51
An annular spacer 61 is interposed between the outer ring 51b and the outer ring 51b.

The planetary shaft 43 has a first support member 70 having a circular plate shape at one end.
The other end is supported by a circular flange-shaped second support member 80 that is integrally formed with the shaft end of the second rotating shaft 20 .

As a result, the first support member 70 faces the first angular ball bearing 50a, and the second support member 80 faces the second angular ball bearing 50b.

Between the first support member 70 and the back surface 52a1 of the inner ring 52a of the first angular ball bearing 50a, the second support member 80 and the back surface 52b1 of the inner ring 52b of the second angular ball bearing 50b.
A wave washer 60 as a resilient member fitted onto the planetary shaft 43 is interposed between the two. This wave washer 60 applies preload to the first angular ball bearing 50a and the second angular ball bearing 50b by the first supporting member 70 and the second supporting member 80, respectively, and thereby The axial gap (internal gap) between the bearing 50a and the second angular ball bearing 50b is eliminated.

Due to the first angular ball bearing 50a and the second angular ball bearing 50b with no axial clearance, the TiX shaft 43 is concentric with the planetary roller 42 and parallel to the axial direction of the first rotating shaft 10 and the second rotating shaft 20. It is placed in a good condition.

Here, the first support member 70 and the second support member 80
The state in which the planetary shaft 43 is locked will be specifically explained.

That is, the first support member 70 and the second support member 80 include
Four lengths a71 and 81 are formed along the radial direction and open at one end to the periphery.

The planetary shaft 43 is supported at both ends by long grooves 71 and 81, and is prevented from being removed by an E-shaped stopper 62. The width of the long groove 71.81 is slightly smaller than the diameter of the planetary shaft 43, and is set so that the planetary shaft 43 has a loose interference fit with the long groove 71.81.

The reason why the itz shaft 43 is supported by the length 171.81 is that due to the tolerance of the length 871.81, the axis of the planetary shaft 43 is parallel to the axes of the first and second rotating shafts 10.20. This is to allow the planetary shaft 43 to escape in the radial direction so that it does not tilt from a normal state.

Next, the operation will be explained.

When the first rotating shaft 10 is used as an input shaft and the second rotating wheel 20 is used as an output shaft, the driving force of the first rotating shaft 10 is
0 is decelerated and transmitted to the second rotating wheel 20 via the planetary roller 42, the planetary shaft 43, and the second support member 80.

Conversely, when the second rotating shaft is used as the input shaft and the first rotating shaft 10 is used as the output shaft, the driving force of the second rotating shaft 20 is transmitted from the second support member 80 to the tlX axis 43, the planetary roller 42, and It is transmitted to the first rotating shaft 10 via the sun roller 40 at an increased speed.

The gap that may occur between the planetary roller 42 and the planetary shaft 43 corresponds to the axial gap of the angular contact ball bearing 50, 51, but in reality there are two gaps between the planetary roller 42 and the planetary shaft 43. Angular contact ball bearing 50.51
, this axial clearance is eliminated by the preload provided by the wave washer 60. In this way, since there is no gap between the planetary roller 42 and the '1ilTL shaft 43, the loss of torque is suppressed to a minimum, and rattling is eliminated when the power transmission direction is reversed.

The first support member 70 and the second support member 80 may be other than those described above, such as those shown in FIGS. 3 and 4, for example. In these figures, the same symbols as those in FIGS. 1 and 2 refer to the same parts or corresponding parts.

That is, the first support member 70a has three protrusions 71a, 71az+71a that protrude in directions shifted by 120 degrees.
= and a circular through hole 71a4 opened in the center part
a first link 71a having a
It consists of Junk 72a3, 72az, and 12a3.

One end of the second link 72a1 is attached to the protruding piece 71a of the first link 71a, and the protruding piece 71az of the first link 71a is attached to the protruding piece 71a of the first link 71a.
One end of the second link 72a2 is connected to the second link 72a2, one end of the second link 72a is connected to the projecting piece 71a of the first link 71a through the shaft 90 and the needle roller 73, respectively. Second link 72a+, 72az, 72a
Each other end of the t is linked to one end of the planetary shaft 43, and an E-type stopper 62 is fitted therein.

The second support member 80a also includes three belt-shaped second links 82a1, 82az, 82as, and a second rotating shaft 2o.
It is composed of three protruding pieces 81a, 81az, and 81a3 that are provided at the shaft end and protrude in directions deviated by 120 degrees. Please note that the parts that do not appear in the drawings are
The portion corresponding to the first support member 70a is shown in parentheses.

One end of the second link 82a is attached to the protruding piece 81a.
1az, one end of the second link 82a2 is connected to the protruding piece 81a3.
One end of the second link 82a is connected to the second link 82a via a shaft 90 and a needle roller 74, respectively. The other ends of the second links 81a, 81az, and 81as are linked to the other end of the planetary shaft 43, and an E-type stopper 62 is fitted therein.

By the way, as can be seen from the drawings, the first support member 70a
and the second support member 80a are connected by a shaft 90 so that their operations are synchronized.

In the above embodiment, two angular ball bearings are provided between the planetary roller 42 and the planetary shaft 43, but the present invention is of course not limited to this. Further, in the above embodiments, the resilient member is described as the wave washer 60, but the present invention is not limited thereto. Furthermore, the first support member 70.70a and the second support member 8
0.80a is not limited to what is explained above,
It goes without saying that various modifications are possible.

<Effect of the invention> According to the present invention, the following effects are exhibited.

The gap that may occur between the planetary shaft and the planetary roller is eliminated by multiple angular contact ball bearings and an elastic member that applies preload to the bearings, thereby suppressing the firing torque to a minimum. In addition, it is possible to prevent rattling when the power transmission direction is reversed.

In particular, when used in speed increasers or speed reducers for industrial robots, etc., by preventing rattling, stable imaging becomes possible, contributing to improved reliability.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 show one embodiment of the present invention;
The figure is a front view schematically showing the power transmission device, and FIG. 2 is a sectional view taken along line nn in FIG. 1. 3 and 4 show other examples of the first support member and the second support member, FIG. 3 is a front view schematically showing the power transmission device, and FIG. 4 is taken along the line IV-IV in FIG. 3. FIG. Furthermore, FIGS. 5 to 7 relate to a conventional example, in which FIG. 5 is a front view schematically showing the power transmission device, FIG. 6 is a sectional view taken along the line Vl-VI in FIG. 5, and FIG. Power transmission g shown in the figure
FIG. 10... First rotating shaft 20... Second rotating shaft 40... Sun roller 41... Fixed ring 42... Planetary roller 43... Planetary shafts 50a, 5Qb... Angular contact ball bearing 60 ...Corrugated washer (spring member).

Claims (1)

[Claims] (1) A sun roller connected to a first rotating shaft, a fixed ring arranged concentrically around the outer periphery of the sun roller, and a plurality of rollers interposed in pressure contact between the fixed ring and the sun roller. a cylindrical planetary roller, a planetary shaft concentrically inserted into each of the planetary rollers and connected to the second rotating shaft, and a plurality of planetary shafts extending in the axial direction between each of the planetary shafts and each of the planetary rollers. A power transmission device comprising individually interposed angular ball bearings and an elastic member that applies preload to each of the angular ball bearings.