JPS6326445Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a circle support device for a motor grader.

As shown in FIGS. 1 to 6, a conventional circle support device of this type has a structure in which a circle c is slidably supported by a plurality of guides b attached to a drawbar a.

In this way, the circle c is simply supported by the guide b, and the contact area between the circle c and the guide b is a sliding contact, resulting in a significant reduction in transmission efficiency. That is, the sliding contact between the circle c and the guide b often causes galling or seizure due to the sliding contact between metals, and a reduction in transmission efficiency has been prevented by applying grease.

In addition, in order to obtain the required circle rotational force, it was necessary to install a motor that generates a considerably large force.

The present invention was developed in view of the above circumstances, and its purpose is to prevent the reduction in transmission efficiency that conventionally occurred due to sliding contact, and also to use a motor for rotating the circle compared to the conventional one. An object of the present invention is to provide a circle support device for a motor grader which can be used with a small output.

Hereinafter, the present invention will be explained with reference to FIG. 7 and subsequent figures.

In the drawing, 1 is a drawbar, and 2 is a circle. A plurality of shaft mounting parts 3 are formed at predetermined intervals on a circle centered on the rotation center of the circle 2 of the drawbar 1, and the upper part of the shaft 4 is fitted into the shaft mounting parts 3. By tightening a nut 5 provided at the upper end of the shaft 4, the shaft 4 is attached to the shaft mounting portion 3 with the shaft mounting portion 3 sandwiched therebetween along with the flanged portion 6. A roller 7 is attached to the lower part of the shaft 4 via a bearing 8.

The circle 2 has a flange-shaped portion 9 formed on its inner circumference, and the flange-shaped portion 9 has internal teeth 10 formed therein.

The circle 2 is guided by the rollers 7 with the lower surface 11 and inner circumferential surface 12 of the brim 9 in contact with the rollers 7.

What is shown in FIGS. 9 and 10 is a circle rotation mechanism 13. This circle rotation mechanism 13 is equipped with a motor 14 fixed to the drawbar 1, and the output shaft 15 of the motor 14 is connected via a worm gear mechanism 16. A pinion 18 provided on the rotating shaft 17 meshes with the internal teeth 10 of the circle 2.

The rotation of the motor 14 causes the circle 2 to rotate via the pinion 18 and the internal teeth 10, and the blade 20 provided on the circle support 19 of the circle 2 to rotate. This rotation of the circle 2 causes the roller 7 to rotate, and the roller 7 smoothly guides the rotation of the circle 2.

As described in detail above, the present invention provides a plurality of shaft mounting parts 3 on a circle centered on the rotation center of the circle 2 of the drawbar 1, and rotates the roller 7 through the shaft 4 on these shaft mounting parts 3. Since these rollers 7 are brought into contact with the lower surface 11 of the brim-shaped portion 9 of the circle 2 and the inner circumferential surface 12 of the circle 2, there is little sliding contact between the circle 2 and the roller 7, and it is almost a rolling contact. The reduction in transmission efficiency that conventionally occurs due to sliding contact can be prevented, and the motor for rotating the circle 2 can have a smaller output than the conventional one.

[Brief explanation of the drawing]

Fig. 1 is a side view of a motor grader, Fig. 2 is a plan view of a conventional circle support device, Fig. 3 is a side view of the same, Fig. 4 is a sectional view taken along the line of Fig. 2, and Fig. 5 is a plan view of a conventional circle support device. Figure 2 - A sectional view taken along the line, Figure 6 is an exploded perspective view of a conventional circle support device, Figure 7 is a longitudinal sectional view of the main part of an embodiment of the present invention, and Figure 8 is an explanation of the internal teeth of the circle. 9 are partially omitted plan views of the circle rotation mechanism, and FIG. 10 is a longitudinal sectional view thereof. 1 is the drawbar, 2 is the circle, 3 is the shaft mounting part,
4 is the shaft, 7 is the roller.

Claims (1)

[Scope of utility model registration request] A plurality of shaft mounting parts 3 are provided on a circle centered on the rotation center of the circle 2 of the drawbar 1, and rollers 7 are rotatably provided to these shaft mounting parts 3 via shafts 4, and these rollers 7 are connected to the circle 2. Flange-like part 9
A circle support device for a motor grader, characterized in that a lower surface 11 of the circle 2 is brought into contact with an inner circumferential surface 12 of the circle 2.