JPS6231281Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a support structure for a rolling wheel such as a grounding tail wheel installed at the rear of a tiller.

Conventionally, in order to rotatably support a rolling wheel on a fixed support shaft, a method such as interposing a bearing and an oil seal between the fixed support shaft and the boss portion of the rolling wheel has been generally adopted. However, in this case, when assembling bearings and oil seals, a high degree of precision is required to fully demonstrate their performance, and these parts themselves are expensive. Together with this, it is disadvantageous in terms of manufacturing costs as a whole, and on top of that, the deterioration of the oil seal over time can lead to rust and wear on the bearings and shafts, causing problems such as the rotation of the wheels becoming slick. Ta.

In view of the above-mentioned circumstances, the purpose of this invention is to reduce the overall cost by using inexpensive parts, and to improve the ability to maintain the rolling wheels in a smooth rotating state for a long period of time. and a bush interposed between the fixed spindle and the boss of the roller fitted on the fixed spindle and fixed to the roller or the fixed spindle in its axial direction. It is divided into two parts, a lubricating oil reservoir is formed between these divided bush parts, and the inner circumferential surface of the boss part of the rolling wheel is formed in a plane parallel to the axis of the fixed support shaft. A surface of the split bushing portion facing the boss portion is formed into a tapered surface, and further, the tapered surface is integrally formed when the bushing is molded.

In other words, the rollers are externally supported on a fixed support shaft using a bushing made of an inexpensive molded product, and the bushing is divided into two parts, and the space between the two divided bushings is used to store lubricating oil. In addition, a tapered lubricating oil supply path for supplying the lubricating oil in the reservoir to the relative rotation sliding part is integrally formed during molding of the bushing, and machining etc. after molding can be easily performed. Combined with the fact that it is not necessary, compared to conventional support structures, it is easier to assemble and reduces costs due to lower manufacturing costs, while maintaining good lubrication performance over a long period of time. It has now become possible to maintain the wheels in a smooth rotating state.

Moreover, in forming a lubricating oil supply path for supplying the lubricating oil in the lubricating oil reservoir to the relative rotation sliding portion on the outer side in the axial direction, the inner and outer circumferential surfaces of the split bushing portion are tapered. Because it is formed in
The fitting accuracy of the split bushing part to the inner peripheral surface of the boss part of the rolling wheel parallel to the axis of the fixed support shaft or the fitting precision of the split bushing part to the fixed support shaft can be made rough, and the split bushing can be easily formed. Become something.

Further, both the split bushing portion and the roller are made of resin molded products, and the outer circumferential surface of the split bushing portion and the inner circumferential surface of the boss portion of the roller are made into irregular shapes, so that they are both fixed. In this case, there is no need for processing or metal fittings for fixing the split bushings and the wheel, and the manufacturing of the wheel support structure,
There are advantages in that assembly can be facilitated and costs can be further reduced.

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in FIG. 1, a transmission case 5 having a control handle 3 and an axle 4 is connected to the rear of a frame 2 for mounting an engine 1, and a wheel that can be freely adjusted in elevation is attached to the rear of the transmission case 5. (below,
It is described as a grounding tail wheel. ) 6 with a rotary tiller 7 fixedly connected thereto,
The support structure of the ground tail wheel 6 is constructed as follows.

That is, as shown in FIGS. 2 and 3, a support shaft 10 in a horizontal position is attached to a U-shaped portion 9A at the lower end of a support member 9 that can be raised and lowered with respect to the rear frame 8 on the tilling device 7 side. Fixedly installed via nuts 11,
A bush 12 interposed between this fixed support shaft 10 and the boss portion 6A of the grounding tail wheel 6 externally fitted thereon and fixed to the tail wheel 6 side is divided into two in the axial direction. However, these two divided bushes 12
A lubricating oil reservoir 13 such as grease is formed between A and 12B, and the inner circumferential surface of the boss portion 6A of the rolling wheel 6 is formed in a plane parallel to the axis of the fixed support shaft 10. Divided bushing part 1 for 10
The lubricating oil in the reservoir 13 is applied to the relative rotation surfaces of 2A and 12B by a relative rotation sliding contact portion a outward in the direction of the rotation axis.
A tapered lubricating oil supply path 14 for supplying
are integrally formed by utilizing the drafting slope during molding of the bush 12.

Both the split bushings 12A, 12B and the tail wheel 6 are made of resin molded products, and
By making the outer circumferential surfaces of the two split bushes 12A, 12B and the boss portion 6A of the tail wheel 6 both elliptical in shape when viewed in the direction of the rotation axis, these two bushes 6 and 12A, 12B are fitted in a non-rotating state. At the same time, the two divided bushing portions 12A,
Annular abutting portions 15, 15 are integrally provided at the outer end of the tail wheel 6 and abut against the axial end of the boss portion 6A of the tail wheel 6.

Further, on both the left and right side surfaces of the tail wheel 6, curved mud-skipping protrusions 1 are disposed such that the further outward in the radial direction, the more displaced toward one side in the rotation direction when viewed in the direction of the rotation axis.
6... are adjacent to the U-shaped portion 9A of the support member 9 and extend from the boss portion 6A to near the outer peripheral surface.

Incidentally, the outer circumferential surfaces of the split bushing portions 12A, 12B and the inner circumferential surface of the boss portion 6A of the wheel 6 are made into an irregular shape such as a square or keyhole shape when viewed in the direction of the rotational axis, so that these two parts 6 and 12A, 12B are The split bushing 12 may be fitted and fixed in a non-rotating state.
A, 12B and the wheel 6 may be fixed via bolts or the like, and furthermore, the two split bushes 12A, 1
2B and the fixed support shaft 10 may be fixed, while the rolling wheels 6 may be configured to be rotatable relative to the split bushes 12A, 12B.

Furthermore, as shown in FIG.
The relative rotational sliding contact portion a with the fixed support shaft 10 is,
It may be configured to have a wide width in the direction of the rotation axis.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of the wheel support structure according to the present invention, and Fig. 1 is an overall side view of the walk-behind cultivator, Fig. 2 is a partially cutaway rear view of the main part, and Fig. 3 is a partial cutaway view of the main part. FIG. 4 is a longitudinal cross-sectional rear view of the main part showing another bush. 6... Roller, 6A... Boss portion, 10... Fixed support shaft, 12... Bush, 12A, 12B... Divided bush portion, 13... Lubricating oil reservoir, 14... Tapered surface.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Intervening between the fixed support shaft 10 and the boss portion 6A of the roller wheel 6 fitted on the fixed support shaft 10 and fixed to the roller wheel 6 or the fixed support shaft 10 side. Butsuyu 1
2 is divided into two parts in the axial direction, and a lubricating oil reservoir part 13 is provided between these divided bush parts 12A and 12B.
The inner circumferential surface of the boss portion 6A of the roller wheel 6 is formed in a plane parallel to the axis of the fixed support shaft 10, and the divided bush portions 12A, 12B for the fixed support shaft 10 and the boss portion 6A are formed. A rolling wheel support structure characterized in that an opposing surface of the bushing 12 is formed as a tapered surface 14, and the tapered surface 14 is integrally formed when the bushing 12 is molded. 2. Both the split bushing parts 12A, 12B and the wheel 6 are molded resin products, and the outer circumferential surfaces of the split bushing parts 12A, 12B and the inner circumferential surface of the boss part 6A of the wheel 6 are made into irregular shapes. The rolling wheel support structure according to claim 1, wherein the divided bushing portions 12A, 12B and the rolling wheel 6 are fixed.