JPS622183B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a stationary wheel body that rotates integrally with a driving shaft at a fixed position in the direction of the rotational axis, and a stationary wheel body that rotates integrally with the driving shaft and moves in the direction of the rotational axis. a cylindrical body that receives and supports a transmission belt in a transmission off state in which the two wheels are separated by a large distance;
The present invention relates to a belt type continuously variable transmission device which is fitted onto the drive shaft so as to be relatively rotatable, and in which a bearing is interposed between the cylindrical body and the drive shaft.

The belt-type continuously variable transmission described above prevents the drive shaft and belt from rotating together when the split pulleys are separated by a large distance to effectively cut off the transmission, thereby ensuring reliable transmission. It has been devised so that a cut state can be obtained. Conventional continuously variable transmissions with this configuration have a bearing interposed between the belt receiving part of the cylindrical body and the driving shaft to improve slippage and further perfect the prevention of co-rotation. .

The problem to be solved by the present invention relates to the compactness of the split pulley or the speed change allowance. In other words, the conventional configuration was excellent in preventing co-rotation, but due to the presence of the bearing in addition to the cylindrical body, the bottom diameter of the belt groove (diameter of the cylindrical body) becomes large, resulting in a problem in power transmission. The minimum belt winding diameter that can be used is inevitably larger than that without a bearing configuration, making it impossible to increase the diameter of the split pulley or reduce the gear shift allowance. The present invention aims to solve the above problems.

A structural feature of the present invention devised to solve the problem is that the bearing is installed inside the cylindrical body part at a position offset in the rotation axis direction with respect to the belt receiving part of the cylindrical body. Another feature of the present invention is that the outer diameter of the belt receiving portion is smaller than the outer diameter of the cylindrical portion in which the bearing is housed.

The effects obtained by the present invention will be explained below. According to the present invention, although bearings are used to completely prevent the driving shaft and belt from rotating together, the outer diameter of the cylindrical body that receives the belt can be reduced to the same degree as that without bearings. Can be made small in diameter. Therefore, while achieving the same effect of completely preventing the drive shaft and the belt from rotating together, the split pulley can be made more compact or the gear shift can be made larger than in the conventional configuration described above.

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. The lawn mowing device 5 is connected to the self-propelled vehicle body equipped with each of them by 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 forming 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.

On the side of the input split pulley 9, as shown in FIG.
The outer diameter of the inner bearing part 17b is provided so that the outer diameter of the belt receiving support part 17a can be as close to the outer diameter of the driving shaft 8 as possible. A cylindrical body 17 formed smaller than the diameter is interposed between a bearing supporting cylindrical body 18 which is externally fitted with a spline so that it can rotate integrally with the driving shaft 8, and both the cylindrical bodies 17 and 18, and the entire body is is connected to the driving shaft 8 via two ball bearings 19, 19 provided at positions offset in the axial direction of the cylinder 17 with respect to the belt receiving portion 17a.
The transmission belt 12 is fitted onto the outside so as to be relatively rotatable, so that the rotation of the transmission belt 12 is reliably stopped when the belt is cut.

In the cylindrical body 17, as shown in FIG.
The operating surface of the belt receiving portion 17a is formed into a curved surface that acts so that the width of the transmission belt 12 in the transmission cut state is smaller than the width in the free state. That is, in the transmission off state, the transmission belt 12 is pressed against the belt receiving portion 17a due to the tension applied by the spring 13, so this pressing force is used to cause the belt 12 to move around both corners of its outer circumference. are deformed into a curved state in which they are closer to each other than in the free state.
In addition, consideration has been given to suppressing the total stroke of the sliding wheel 9a as small as possible while ensuring that the sliding wheel 9a is separated from the transmission belt 12 so as not to come into contact with it when the cutting operation is performed. It has been done. Further, the total width l of the belt receiving portion 17a is formed to be smaller than the total width of the transmission belt 12 so that the belt receiving portion 17a does not come into contact when the sliding wheel body 9a approaches the stationary wheel body 9b. Recessed portion 20 that needs to be formed in the sliding wheel body 9a to allow the
The sliding wheel body 9a is designed to be as compact as possible, and its dimensions in the sliding direction are as small as possible.

The seal 21 shown in FIG. 3 is for preventing lubricating oil from leaking into the bearing 19.

The above-described continuously variable transmission device can also be applied to various work vehicles such as rice transplanters and tillers.

[Brief explanation of the drawing]

The drawings show an embodiment of the belt-type continuously variable transmission according to the present invention, in which Fig. 1 is a side view of a lawn mower, Fig. 2 is a sectional view of the transmission, and Fig. 3 is a sectional view showing the operating state of the cylinder. It is a diagram. 8... Driving shaft, 17... Cylinder, 17a... Belt receiving portion, 17b... Cylinder part, 9... Split pulley, 9a... Sliding side wheel body, 9b... Fixed side wheel body, 19...Bearing.

Claims (1)

[Claims] 1. A fixed side wheel 9b that rotates integrally with the driving shaft 8 at a fixed position in the direction of the rotational axis, and a sliding side wheel that rotates integrally with the driving shaft 8 and can freely move in the direction of the rotational axis. A cylindrical body 17, which receives and supports the transmission belt 12 in the transmission off state in which the two wheel bodies 9a and 9b are separated by a large distance, is rotated relative to the driving shaft 8. In a belt-type continuously variable transmission device in which a bearing 19 is freely fitted onto the outside and interposed between the cylindrical body 17 and the driving shaft 8, the bearing 19 is attached to the belt receiving portion 17a of the cylindrical body 17. The belt receiving part 17a is installed inside the cylindrical body part 17b at a position offset in the direction of the rotation axis, and the outer diameter of the belt receiving part 17a is formed to be smaller than the outer diameter of the cylindrical body part 17b in which the bearing 19 is installed. Features a belt-type continuously variable transmission.