JPH0222469Y2 - - Google Patents

Description

[Detailed explanation of the idea] Industrial applications This invention relates to a wheel device.

Prior Art and Its Problems In order to make the wheels rotate smoothly, the following wheel devices have been devised. For example, it consists of a wheel with a shaft hole, a synthetic resin oil-impregnated bushing tightly fitted into the shaft hole of the wheel, and a shaft loosely passed through the bushing. An annular projection is provided all around the shaft hole, and an annular groove is formed around the entire circumference in which the annular projection can fit tightly into the inner peripheral surface of the shaft hole. (see publication). however,
This wheel device had the following problems. That is, since the annular projection is provided on the outer peripheral surface of the bushing, it has been impossible to mold the bushing and the wheel separately and then insert the bushing into the shaft hole of the wheel from one end thereof. Therefore, when assembling a wheel device, it is necessary to mold an oil-impregnated bush in advance, place it in a mold, and then integrally mold the wheel around the oil-impregnated bush, which is a cumbersome process. However, it has poor productivity and is not suitable for mass production. Moreover, the cost is high. In addition, the bushings are made of synthetic resin impregnated with lubricating oil, but the impregnated oil does not provide sufficient lubricity, and there is a risk that the wheels will not rotate smoothly if a large load is applied to the wheel device. There is.

In addition, conventionally, two synthetic resin flanged bearing components are inserted between the shaft and the circumferential surface of the shaft hole of the wheel from both sides of the wheel, from the non-flange side, so that their tips do not come into contact with each other. A wheel device in which grease was placed in the space between the tips of the bearing components was also considered (see Japanese Utility Model Application No. 48-6844). However,
This wheel device also had the following problems. In other words, when a large load is applied to the wheel device,
There is a possibility that the axes of both bearing components may be misaligned, or the bearing components may come out of the wheel, resulting in malrotation. Furthermore, since two bearing components are required, the number of parts increases, and when assembling the wheel device, each bearing component must be inserted into the wheel separately, which reduces productivity and hinders mass production. Not suitable. Moreover, the cost increases.

The purpose of this invention is to provide a wheel device that solves the above problems all at once.

Means for Solving the Problems The wheel device according to this invention consists of a wheel having a shaft hole, a bush fitted into the shaft hole, and a shaft inserted through the bush. An annular groove extending all the way around the inner peripheral surface is formed, and a lubricating oil filling hole is formed in the middle part of the bushing length, passing through the bushing in the radial direction, and the bushing diameter perpendicular to the axial direction of the lubricating oil filling hole The thickness of the bushing peripheral wall on both sides of the bushing is thinner than the other parts, and a protrusion extending in the circumferential direction that fits into the annular groove is provided on the outer peripheral surface of the thinned part.

Embodiments This invention will be described below with reference to embodiments shown in the drawings.

The door wheel (wheel device) 1 includes a synthetic resin wheel 3 having a shaft hole 2, a synthetic resin bush 4 tightly fitted into the shaft hole 2 so as not to rotate, and a bush 4.
It consists of a metal shaft 5 inserted through the.

An annular groove 6 is formed on the inner peripheral surface of the shaft hole 2 of the wheel 3 over the entire circumference. A lubricating oil filling hole 8 having a vertically rectangular cross section and passing through the bush 4 in the radial direction is formed in the center of the length of the bush 4.
is filled with lubricating oil 9. The width of the bush 4 in the radial direction perpendicular to the axial direction of the hole 8, that is, the width in the vertical direction in FIGS. 1 and 2 is larger than the inner diameter of the bush 4, and therefore,
The wall thickness of the peripheral wall 10 of the bush 4 at both upper and lower portions of the hole 8 is thinner than other portions. This thin portion is indicated by 10a. A protrusion 7 extending in the circumferential direction and capable of fitting into the annular groove 6 is formed on the outer peripheral surface of the thin portion 10a.

This door roller 1 is assembled as follows. That is, first, the wheel 2, bush 4, and shaft 5 are formed separately. Then, the bush 4 is press-fitted into the shaft hole 2 from one side of the wheel 3. At this time, the thin portion 10a is bent in the direction of arrow A, and the protrusion 7 is bent toward the wheel 3.
The projection 7 enters into the groove 6 without getting caught in the area around the open end of the shaft hole 2 on the side surface of the shaft hole 2.
When it reaches the part where , it restores to its original shape and the protrusion 7
fits into the annular groove 6. After that, Butsuyu 4
Insert the shaft 5 through. After the bush 4 is forcibly fitted into the shaft hole 2, the shaft 5 is inserted into the bush 4, so the thin part 10a does not bend, and due to the action of the annular groove 6 and the protrusion 7 fitted therein, The bush 4 is completely prevented from falling off from the shaft hole 2.

In the above embodiment, the bush 4 is press-fitted into the shaft hole 2 of the wheel 3 and fixed, and the bush 4 integrated with the wheel 3 rotates around the shaft 5, but the invention is not limited thereto. , axis 5 is bush 4
The wheel 3 may rotate around a bushing 4 which is fixed to the shaft 5 and is integral with the shaft 5, or the wheel 3, the bush 4 and the shaft 5 may each rotate relative to each other. In these cases as well, good lubrication performance can be obtained by the lubricating oil 9 in the lubricating oil filling hole 8.

Effects of the invention According to the wheel device of this invention, a hole for filling lubricating oil is formed in the middle part of the length of the bushing, so if this hole is filled with lubricating oil, sufficient lubrication can be achieved. Even when a large load is applied to the wheel device, the wheel always rotates smoothly, and its effect is maintained for a long time. Moreover, since it consists of only a wheel having a shaft hole, a bushing fitted into the shaft hole, and a shaft inserted through the bushing, the number of parts is small, making it possible to reduce costs and improve productivity.

In addition, the lubricating oil filling hole penetrates the bush in the radial direction, and the thickness of the bushing peripheral wall on both sides of the bushing in the radial direction perpendicular to the axial direction of the lubricating oil filling hole is thicker than the other parts. made thin,
Since a protrusion extending in the circumferential direction that fits into the annular groove is provided on the outer peripheral surface of the thin-walled portion, the wheel device is assembled by press-fitting the bushing into the shaft hole from one side of the wheel, and then inserting the shaft into the bushing. This can be done by simply inserting the In other words, when the bushing is press-fitted into the shaft hole, the thin wall portion bends inward in the radial direction due to the existence of the lubricating oil filling hole that penetrates the bushing in the radial direction, and the protrusion forms the opening end of the shaft hole on the side surface of the wheel. The protrusion enters the interior without being caught by the surrounding parts, and when it reaches the position where the annular groove exists, it restores its original shape and the protrusion fits into the annular groove. Therefore, assembly becomes easier and productivity is improved.

Furthermore, an annular groove extending all the way around is formed on the inner circumferential surface at the middle of the length of the shaft hole of the wheel, and a protrusion extending in the circumferential direction that fits into the annular groove is provided on the outer circumferential surface of the thin part of the bushing. Since the shaft is inserted through the bush, even when a large load is applied, the axis of the bush is prevented from shifting from the axis of the wheel, and the bush is prevented from falling out of the shaft hole. Therefore, rotation failure will not occur.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention; FIG. 1 is an exploded perspective view, FIG. 2 is a vertical sectional view, and FIG. 3 is a horizontal sectional view. 1... Door roller, 2... Shaft hole, 3... Wheel, 4...
Bush, 5... Shaft, 6... Annular groove, 7... Protrusion, 8... Lubricating oil filling hole, 10a... Thin wall portion.

Claims (1)

[Scope of utility model registration request] Consisting of a wheel 3 having a shaft hole 2, a bush 4 fitted into the shaft hole 2, and a shaft 5 inserted through the bush 4, an annular ring is formed on the inner circumferential surface of the shaft hole 2 in the middle of its length. A groove 6 is formed, and a lubricating oil filling hole 8 that penetrates the bushing 4 in the radial direction is formed in the middle of the length of the bushing 4. A wheel device in which the circumferential wall of the bush 4 at both side portions is thinner than the other portions, and a projection 7 extending in the circumferential direction that fits into the annular groove 6 is provided on the outer peripheral surface of the thin portion 10a. .