JPS6158701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a differential speed reducer using a planetary mechanism, and particularly to a differential speed reducer using a planetary mechanism that transmits power by rolling contact, which is quiet in operation.

Reduction gears using a planetary mechanism are generally made up of gears, which make a lot of noise. For this reason, there are planetary speed reducers that use rolling contact, but although they operate quietly, they have a small reduction ratio and are large in size. This problem can be solved by outputting a differential output, but the planetary differential speed reducers that have been proposed so far have had the drawback of being difficult to manufacture.

The present invention has been made in view of these points, and its purpose is to provide a planetary type differential reducer that is compact, has a large reduction ratio, operates quietly, and is easy to manufacture. It is on offer.

To explain the present invention below, the present invention includes a sun roller, a planetary roller that rolls into contact with the outer peripheral surface of the sun roller, a first inscribed ring and a second inscribed ring with which the planetary roller rolls and contacts the inner peripheral surface of each of the sun rollers. The second inscribed ring has greater elasticity and shorter inner circumference than the first inscribed ring, and the inner circumference of the pair of inscribed rings is Although a differential output can be obtained because of the difference, the planetary rollers that roll into contact with both inner rings need only have a single diameter.The present invention will be described in detail below based on the illustrated embodiment. , 1 in the figure
is the sun roller, and the side wheels 1 at both ends in the axial direction
1 and 12 are integrally formed on the input shaft 10. A plurality of planetary rollers 2 are arranged at equal intervals around the axis of the sun roller 1 by means of retainers 5. The diameter is the same throughout the entire axial length,
Each planetary roller 2 supported by a retainer 5
A pair of inscribed rings 3 and 4 are disposed on the outer periphery of the planetary roller 2, and each planetary roller 2 rolls into contact with the inner peripheral surface of the planetary roller 2. These inscribed rings 3 and 4 are attached coaxially with the sun roller 1 by means such as shrink fitting or press fitting, and are provided between the planetary roller 2 and the sun roller 1 and between the planetary roller 2 and both inscribed Contact pressure is generated to prevent slipping between the rings 3 and 4.

Here, both inscribed rings 3 and 4 have different inner circumferential lengths when they are installed, and inscribed ring 4 has a shorter inner circumferential length than inscribed ring 3, that is, its average diameter is smaller. has been done. The inner ring 4 has greater elasticity than the inner ring 3. The larger the difference, the better;
Further, it is desirable that the planetary roller 2 has high rigidity. The difference in elasticity (rigidity) between the two inscribed rings 3 and 4 can be obtained by using different materials, such as iron and synthetic resin molded products, or by using materials with a significant difference in section modulus (secondary moment of inertia). . In the figure, 6 is a bearing for supporting the retainer 5 and for attaching the entire system to a housing (not shown).

When the input shaft 10 integrated with the sun roller 1 is rotated, power is transmitted to the inscribed rings 3 and 4 through the rotation of the planetary roller 2, but now the inscribed ring 3 is braked. If the planetary roller 2 is stopped or fixed in advance, the revolution of the planetary roller 2 is determined by the inner peripheral length of the internal roller 3. At this time, the inscribed ring 4, which has an inner circumference shorter than the inscribed ring 3, receives the power from the planetary roller 2, and
Differential rotation is performed in a direction opposite to the rotational direction of the input shaft 10 and with a large reduction ratio due to the difference in the inner circumferential lengths of the two inscribed rings 3 and 4. A planetary roller 2 that rolls into contact with the inner rings 3 and 4,
Although the portions in contact with both of the internal rings 3 and 4 have the same diameter, they are capable of producing a differential output.

As described above, since the present invention transmits power by rolling contact and can generate differential output, it is compact, has a large reduction ratio, and has quiet operation noise. Since one of the rings has greater elasticity and a shorter inner circumference than the other, the planetary roller does not need to have two diameters that correspond to the inner circumference of each inscribed ring, that is, the average diameter. , because they have the same diameter, they are easy to structure and manufacture.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line A-A, and FIG. 3 is a cross-sectional view taken along the line B-B. ,
3 and 4 indicate inscribed rings.

Claims (1)

[Claims] 1 Consisting of a sun roller, a planetary roller that rolls into contact with the outer peripheral surface of the sun roller, and a first inscribed ring and a second inscribed ring with which the planetary roller rolls and contacts the respective inner peripheral surfaces, A differential speed reducer characterized in that a second inscribed ring has greater elasticity and a shorter inner peripheral length than the first inscribed ring.