JPH0214685Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a planetary roller type power transmission device that transmits power by the frictional force of rollers that are in contact with each other.

<Prior Art> As shown in FIG. 2 showing an example of a conventional planetary roller type power transmission device and FIG.
and an output shaft 3 coaxially pass through the shaft 3, and are rotatably supported independently by bearings 4, 5, and 6, respectively. A plurality of planetary pins 7 are integrally protruded from the end of the output shaft 3, and planetary rollers 8 are attached to these.
is rotatably supported via a bearing 9. These planetary rollers 8 are rotatably abutted on the outer periphery of a sun roller 10 that is integral with the input shaft 2.
This casing 1 and cover 1 are inside casing 1.
A plurality of (in the illustrated example, two) inner rollers 12 having a groove-shaped cross section are provided, which are sandwiched between the inner rollers 12 and
A spacer 13 is interposed between these.
Note that the reference numeral 14 in the figure is a tightening bolt for tightening the cover 11 to the casing 1.

A fourth image representing the state before the inner roller 12 is assembled.
As shown in Figure a, the width of the inner roller 12 is Wi, and after the cover 11 is attached to the casing 1 with the tightening bolts 14, the width of the inner roller 12 is Wi, as shown in Figure 4B, which shows the state at this time. , the inner roller 12 is held between the cover 11 and the casing 1 and receives an axial pressing force T. As a result, the width of the inner roller 12 is
is compressed elastically from Wi to Wt, and its inner diameter
Di is reduced by 2C while forming a crowning deformation with radius r as Dn. This results in
At the point of contact with the planetary roller 8, the crowning deformation is restrained, and a roller pressing force P corresponding to the amount of deformation C is generated, making it possible to transmit the driving force by friction, and from the input shaft 2 side. Power is transmitted to the output shaft 3 side.

In this way, in order to obtain the roller pressing force P, it is sufficient to elastically deform the width of the inner roller 12 from Wi to Wt, but in the above example, the width dimension of two inner rollers 12 is (Wi - Wt ) The overlap thickness V of the cover 11 is set to be reduced by x2.

<Problems to be solved by the invention> Inner roller 1 of conventional planetary roller type power transmission device
2, when its width is reduced from Wi to Wt, its side end face is inclined by an angle θ as shown in FIG. 4b.
Therefore, the pressure receiving part M of the axial pressing force T for maintaining the deformation of (Wi-Wt) has a linear distribution of diameter Dk, and it is impossible to avoid excessive surface pressure there. For this reason, conventionally, a spacer 13 having a width S is indispensable, but the provision of this spacer 13 increases the axial dimension of the device and causes an increase in cost.

In view of this knowledge, it is an object of the present invention to provide a planetary roller type power transmission device in which spacers are omitted to reduce the size and cost of the device.

<Means for Solving the Problems> The planetary roller type power transmission device of the present invention has a sun roller connected to a first shaft, and a second shaft coaxial with the first shaft, each rotatable. A planetary roller type power transmission device comprising a plurality of supported planetary rollers, and inner rollers having a grooved cross section that are arranged in double rows concentrically with the shaft and in rolling contact with the inner circumferential surface of each of the planetary rollers, It is characterized in that the side end surfaces of the inner rollers in double rows are brought into direct contact with each other, and the inner diameters of these contacting side end surfaces are formed to have different dimensions.

<Function> By forming the inner diameters of the side end surfaces of the inner rollers that are in contact with each other to have different dimensions, the contact state of the side end surfaces of the inner rollers due to the axial pressing force becomes a line-to-plane contact, which prevents excessive surface pressure. Occurrence is prevented.

<Embodiment> As shown in FIG. 1, which shows the structure of an embodiment of the planetary roller power transmission device according to the present invention, the double-row inner rollers 12 are in direct contact with each other. The spacer that was used has been discontinued. The inner diameter dimensions of the pressure receiving portions for receiving the axial pressing force T against the side end surfaces of the inner rollers 12 are slightly different, Dk for one and Dr (Dk>Dr) for the other.
It should be noted that members with the same functions as the conventional one shown in FIG. 2 are designated by the same reference numerals in the drawings.

Therefore, even if the width of each inner roller 12 is compressed to Wt and both end surfaces thereof are inclined by the angle θ, the contact state of the side end surfaces of the inner rollers 12 becomes line-to-plane contact, and the inner rollers of each other The pressure-receiving portion M' of the axial pressing force T acting on 12 can be formed in the same manner as the pressure-receiving state of the other portions.

<Effects of the invention> According to the invention, the inner diameters of the side end surfaces of the inner rollers in double rows that contact each other are formed to have different dimensions, so that the contact state of the side end surfaces of the inner rollers due to the axial pressing force is reduced. The contact between the wire and the surface effectively prevents excessive surface pressure on the pressure-receiving portion, thereby improving the durability and reliability of the component. In addition, since the spacer that was previously interposed between the inner rollers has been abolished,
The axial dimension of the device can be reduced by the width of this spacer, and costs can be reduced accordingly.

[Brief explanation of drawings]

FIG. 1 is a half-cut sectional view showing the structure of an example of a planetary roller type power transmission device according to the present invention, FIG. 2 is a half-cut sectional view of an example of a conventional planetary power transmission device, and FIG.
The figure is a sectional view taken in the direction of the - arrow, and FIGS. 4a and 4b are conceptual diagrams showing the states of the inner roller before and after applying the pressing force, respectively. In the drawing, 1 is a casing, 2 is an input shaft, 3 is an output shaft, 8 is a planetary roller, 10 is a sun roller, 11
12 is a cover, 12 is an inner roller, and 13 is a spacer.

Claims (1)

[Scope of utility model registration request] A sun roller connected to a first shaft, a plurality of planetary rollers each rotatably supported by a second shaft coaxial with the first shaft, and these planetary rollers each roll into contact with the inner circumferential surface. In a planetary roller power transmission device comprising inner rollers with grooved cross sections arranged in double rows concentrically with the shaft, the side end surfaces of the double rows of inner rollers are brought into direct contact with each other, and the side end surfaces in contact with each other are provided. A planetary roller type power transmission device characterized in that the inner diameters of the two are formed to have different dimensions.