JPS623336B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a belt-type continuously variable transmission device in which a rotating body for receiving and supporting a transmission belt in a cut state is fitted around a driving shaft so as to be relatively rotatable.

The above-mentioned continuously variable transmission is designed so that the rotating body prevents the transmission belt from rotating together with the drive shaft during cutting operations, resulting in poor cutting. Since the belt receiving surface was formed as a flat cylindrical surface, in order to prevent the belt received by the rotating body from rotating together with the pulley, it was necessary to make sure that the belt and pulley were sufficiently far apart.
The wheel forming the pulley must be moved widely,
As a result, problems such as the need to increase the stroke of the wheel forming the pulley, making the transmission larger, and the need to increase the stroke of the operating tool, making it difficult to install it in a narrow space. It was happening.

SUMMARY OF THE INVENTION It is an object of the present invention to minimize the stroke required to move the pulley sufficiently away from the belt, and to require simple modification.

A characteristic configuration of the present invention is that, in the above-mentioned belt-type continuously variable transmission, the recessed portion that bends and deforms the cut transmission belt into a shape in which the outer circumferential surface is recessed and curved in the width direction by the belt tension is rotated. This is because it is formed on the outer periphery of the body.

In other words, in general, the cross-sectional shape of the power transmission belt used in this type of transmission device in its free state is a trapezoidal shape that is wider toward the outer circumferential surface, and the outer circumferential surface is deformed into a concavely curved shape in the width direction. Then, the width in the deformed state is smaller than the width in the free state. Therefore, by allowing the transmission belt to deform into the shape described above when received by the rotating body, the stroke required to move the pulley away from the belt received by the rotating body can be reduced. Compared to the conventional belt receiving surface of the rotating body, which was a flat surface, the belt width can be reduced by the narrower belt width, and it is now possible to construct a compact device that can reliably prevent cutting defects. In addition, the modification can be done simply by adding the recessed portion, which is advantageous from an economic point of view.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, it is equipped with a pair of left and right front wheels 1, 1 that can be freely steered, and a pair of left and right drive rear wheels 2, 2, as well as a driving unit 3 and a driving unit 4 disposed behind it. A lawn mowing device 5 is connected to a self-propelled vehicle body equipped with a link mechanism, with the lawn mowing device 5 positioned between the front and rear wheels, so that it can be raised and lowered, and
A riding type lawn mower is constructed by transmitting rotational force from a self-propelled vehicle to the lawn mowing device 5.

As shown in FIG. 2, the engine 6
An input split pulley 9 is attached to the drive shaft 8 which is linked to the transmission, and an output split pulley 11 is rotatably attached to the input shaft 10 of the transmission, and a transmission belt 12 is wound around both pulleys 9 and 11. , the slidable wheel 11a constituting the output split pulley 11 is slidably biased toward the stationary wheel 11b by a spring 13 to apply tension to the transmission belt 12; , the hawk 16, which is locked to the boss portion of the slidable wheel 9a forming the input split pulley 9 via the bearing 14 and the wheel 15, is swung, and the wheel 9a is moved to the fixed side. A belt-type continuously variable transmission is configured so that the vehicle body moves at variable speeds by approaching and separating from the wheel body 9b, and also stops transmission to the transmission by disengaging the transmission belt 12.

The rotating body 17 is attached to the bearing 1 on the driving shaft 8.
8. The bearing support tube 19 and the sliding wheel body 9a are fitted externally through the boss portion of the sliding wheel body 9a, and when cut, the transmission belt 12 is pulled toward the driving shaft 8 by the spring 13. and is configured to be received and supported at one end of the rotating body 17, and the belt supporting surface of the rotating body 17 is
A concave curved surface 20 curved in the axial direction of the cylinder is formed around the entire circumference of the rotating body, so that in the cut state, as shown in FIG. 3, the belt 12 is supported by the rotating body 17. The belt 12 and the drive shaft 8 are prevented from rotating together, and the outer peripheral surface is curved in the width direction due to the belt tension that presses the belt 12 against the recessed curved surface 20 and the shaping action of the recessed curved surface 20. The belt 12 is flexibly deformed into a shape such that a gap is created between the lateral end surface of the belt and the inner surface of the pulley, and the belt width (L ₁ ) is smaller than the width (L ₂ ) in the free state. It is configured.

In order to bend and deform the belt 12 into the above-mentioned shape, as shown in FIG.
An annular groove 21 having a width narrower than the width of the inner circumferential surface of the belt 12 is formed in the outer circumferential portion for receiving and supporting the belt 12, and both lateral ends of the belt 12 are connected to a pair of corner portions 22, 2.
2, the part of the belt 12 located between the two corners 22, 22 may be drawn into the groove 21 by belt tension, and the recessed curved surface 20 and The grooves 21 are called recesses 20 and 21 that bend and deform the belt 12 into the above-mentioned shape by belt tension.

Incidentally, since the groove 21 is a rectangular groove, it can be easily fabricated, which is economically advantageous.

The present invention can also be applied to various work vehicles such as combine harvesters, binders, and rice transplanters, and to belt-type continuously variable transmissions used for various transmission purposes other than travel.

[Brief explanation of the drawing]

The drawings show an embodiment of the belt-type continuously variable transmission device according to the present invention, and FIG. 1 is an overall side view of a riding lawn mower.
FIG. 2 is a sectional view of the transmission, FIG. 3 is a sectional view showing the operating state of the rotating body, and FIG. 4 is a sectional view showing another implementation structure of the rotating body. 8... Driving shaft, 12... Transmission belt, 17...
Rotating body, 20, 21... recessed part.

Claims (1)

[Claims] 1. A belt-type continuously variable transmission in which a rotary body 17 for receiving and supporting a cut-off transmission belt 12 is fitted onto a drive shaft 8 so as to be relatively rotatable, and the outer circumferential surface of the cut-off transmission belt 12 is A belt-type continuously variable transmission device in which a recessed portion 20 or 21 is formed on the outer periphery of the rotating body 17 to be bent and deformed by belt tension into a shape that is recessed and curved in a direction.