JP3755952B2 - Caster wheel shaft support structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a wheel shaft support structure of a caster, particularly a caster suitable for a front wheel of a wheelchair.
[0002]
[Prior art]
Conventionally, the wheel shaft support structure of a caster has rolling bearings 104 and 104 fitted in bearing holes 103 and 103 provided at both left and right ends of a shaft hole 102 penetrating through the center of the wheel 101 as shown in FIG. The collar portions 107, 107 having collar portions 106, 106 provided on the outer ends of the cylindrical portions 105, 105 having a length that substantially bisects the outside of the rolling bearings 104, 104 are connected to the cylindrical portions 105, 105 from the outside. The wheel 101 is inserted into the abutted state, and the wheel 101 is sandwiched between the left and right arms 109, 109 of the fork 108, and the shaft holes 110, 110 provided at the distal ends of the arms 109, 109 and the flange collar 107 , 107 are inserted into the cylindrical portions 105, 105, and a nut 112 is screwed into a screw portion provided at the tip of the support shaft 111 outside one arm 109 and tightened. It was allowed to supported.
[0003]
[Problems to be solved by the invention]
The conventional wheel shaft support structure of a caster thus configured has a length between both outer ends of the rolling bearings 104, 104 fitted in bearing holes 103, 103 provided at both ends of the shaft hole 102 of the wheel 101. It is difficult to make the length between the flange portions 106, 106 of the flange collars 107, 107 difficult to match, and the length of the cylindrical portions 105, 105 of the flange collars 107, 107 is the rolling bearing 104, 104. When the support shaft 111 is tightened with the nut 112, there is no support for the inner side of the rolling bearings 104, 104, so that they are curved inward to each other and are normally rotated. In other words, the length of the cylindrical portions 105, 105 of the flanged collars 107, 107 is made longer than the length between both outer ends of the rolling bearings 104, 104. Comb had. However, there is a gap between the inside of each flange 106 and the outside of each rolling bearing 104, and rattling occurs. However, it is possible to correct the rattling by filling an adhesive into these gaps. It was.
Accordingly, an object of the present invention is to provide a caster wheel shaft support structure which is improved so that normal rotation can be performed without correcting rattling of the wheel 101.
[0004]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention is provided between a pair of arms in which a wheel in which a rolling bearing is fitted into bearing holes provided at both left and right ends of a shaft hole penetrating the center of the wheel is protruded from a fork. Caster wheel shaft support structure in which the support shaft passes through the shaft hole provided in the arm and the shaft insertion hole of each rolling bearing fitted to the wheel, than the width of the shaft insertion hole of the rolling bearing. Each of the rolling bearings is fitted inside a rolling bearing fitted with a bearing hole of the wheel, with a collar with a slightly short cylindrical portion fitted into the shaft insertion hole with the collar portions facing outward. By interposing a spacer having a length equal to the interval between the roller bearings, the rolling bearings are sandwiched between the flange portions of the collars and the spacers so that the wheels can be rotated normally without rattling.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of a wheelchair in which a caster to which a wheel shaft supporting structure according to the present invention is applied is mounted on a front wheel, FIG. 2 is an exploded perspective view of a main part of the present invention, and FIG. 3 is a state in which members shown in FIG. FIG. The wheelchair 1 shown in FIG. 1 has a pair of left and right frame-shaped support members 2 and 2 combined so that they can be folded, and main wheels 3 and 3 erected at the rear of the support members 2 and 2 with rear wheels 4 and 4. The operation wheels 5 and 5 are pivotally supported, and the support shafts 8 of the front wheel casters 7 and 7 are inserted and fixed to the fixing members 6a at the lower ends of the support rods 6 and 6 suspended near the front portions of the support members 2 and 2. And attach. Both ends of the seat 10 are supported by the horizontal rods 9, 9 provided on the support members 2, 2, and both ends of the backrest sheet 11 are supported by the upper portions of the main rods 3, 3. Grip portions 12 and 12 for the caregiver to push the wheelchair 1 are provided at the upper ends of the main rods 3 and 3. Footing plates 13 and 13 are provided at the lower front ends of the support members 2 and 2. 14 and 14 are brake levers for stopping the rear wheels 4 and 4.
[0006]
In FIG. 2, reference numeral 15 denotes a fork that rotatably supports the wheel 16. The fork 15 projects a pair of left and right arms 18, 18 from the lower end of the cylindrical body 17, and is provided at the tip of each arm 18, 18. Shaft holes 19 and 19 for supporting the wheel 16 are provided and integrally formed by plastic injection molding. Then, rolling bearings (not shown) are fitted to the upper and lower end portions inside the cylindrical body 17, and the support shaft 8 is rotatably supported via these rolling bearings.
[0007]
The wheel 16 is integrally formed by insert injection molding a tire portion 20 around a wheel body 16a, and a shaft cylinder 22 is provided at the center of a spoke 21 formed radially inside, and a shaft hole penetrating the shaft cylinder 22 is provided. Bearing holes 25 and 25 for fitting the outer rings of the rolling bearings 24 and 24 to the left and right ends of the shaft 23 are provided with a larger diameter than the shaft hole 23.
[0008]
26 and 26 are collars provided with collars 27 and 27 at one end, and the length of the cylindrical part 28 is set slightly shorter than the width of the rolling bearing 24.
Reference numeral 29 denotes a cylindrical spacer interposed in the shaft hole 23 inside the rolling bearings 24, 24. The length of the spacer 29 matches the distance between the rolling bearings 24, 24 fitted in the bearing holes 25, 25. It is set as follows.
Then, the outer rings of the rolling bearings 24, 24 are fitted into the bearing holes 25, 25 provided at both ends of the shaft hole 23 with the spacer 29 interposed in the shaft hole 23, respectively. The collars 26, 26 are fitted into the shaft insertion holes 30, 30 so that the collar portions 27 face outward, and communicate with the spacer 29. If the collar 26 and the spacer 29 are made of wear-resistant engineering plastic, dimensional processing is facilitated.
[0009]
Reference numeral 31 denotes a support shaft that supports the wheel 16, and a nut 33 is screwed to a screw portion 32 provided at the tip. Reference numerals 34 and 34 are plain washers, and 35 is a spring washer.
Next, the assembly of the caster 7 will be described in order.
The wheel 16 having the collars 26 and 26 and the spacers 29 communicated with each other is sandwiched between the arms 18 and 18 of the fork 15, and a plain washer 34 is overlapped on the outer side of one arm 18 to support the shaft hole 19. The shaft 31 is inserted, and the support shaft 31 is inserted in the order of the flanged collar 26 fitted to the rolling bearing 24 of the wheel 16, the spacer 29 and the flanged collar 26, and then inserted into the shaft hole 19 of the other arm 18. Then, after the plain washer 34 and the spring washer 35 are fitted and inserted, the nut 33 is screwed onto the screw portion 32 at the tip of the support shaft 31 and assembled as shown in a cross section in FIG.
[0010]
In the caster 7 assembled in this way, the wheel 16 pivotally supported on the arms 18 and 18 of the fork 15 via the support shaft 31 is fitted into the bearing holes 25 and 25 provided at the left and right ends of the shaft hole 23. Each of the rolling bearings 24 and 24 is supported on the inner side by a spacer 29 and supported on the outer side by a flange portion 27 of a flange collar 26. Moreover, the cylindrical portion 28 is slightly shorter than the width of the rolling bearing 24, and the cylindrical portions 28, 28 of the flanged collars 26, 26 do not come into contact with the tip of the spacer 29, so that the cylindrical portions 28, 28 and the spacer 29 are not in contact with each other. Since there are gaps S and S, and the inner and outer sides of the rolling bearings 24 and 24 are firmly supported by the flange portions 27 and 27 of the collars 26 and 26 and the spacer 29, the rolling bearings 24 and 24 are provided. Will not be bent inward or the wheels 16 will not rattle. Therefore, the wheel 16 can rotate smoothly.
[0011]
【The invention's effect】
As described above, the wheel shaft support structure of a caster according to the present invention has a length slightly shorter than the width of the rolling bearing in the shaft insertion hole of the rolling bearing fitted into the bearing holes provided at both ends of the wheel shaft hole. A collar with a cylindrical part is fitted and inserted so that the collars face each other, and a spacer is inserted inside each rolling bearing, and the support shaft is inserted through the shaft hole provided in the arm of the fork. Since each of the rolling bearings fitted into the bearing holes at both ends of the shaft hole of the wheel is supported by the spacer on the inside and the outside is It is firmly supported by the collar part of the collar, and there is no gap between the collar bearings at the collar part of the collar, so there is no need to fill the gap with an adhesive, and the rolling bearing is curved inward. Because there is no It can be rotated smoothly not be able. Therefore, particularly when used by being attached to a wheelchair as a wheelchair front wheel caster, it is possible to move the wheelchair smoothly by eliminating wheel shaki that is most hated.
[Brief description of the drawings]
FIG. 1 is a perspective view of a wheelchair in which a caster to which the present invention is applied is attached to a front wheel.
FIG. 2 is an exploded perspective view of a main part of the present invention.
FIG. 3 is a cross-sectional view of a main part of the present invention.
FIG. 4 is a cross-sectional view of a main part showing a conventional example.
[Explanation of symbols]
7 Caster 15 Fork 16 Wheel 18, 18 Arm 19, 19 Shaft hole 23 Shaft hole 24, 24 Rolling bearing 25, 25 Bearing hole 26, 26 ， collar 27, 27 ２８ portion 28, 28 Tube portion 29 Spacer 30, 30 shaft Insertion hole 31 Spindle

Claims (1)

A wheel in which a rolling bearing is fitted in bearing holes provided at the left and right ends of a shaft hole penetrating the center of the wheel is interposed between a pair of arms projecting from a fork, and the shaft hole provided in the arm and the above-mentioned In the wheel shaft support structure of a caster that allows the support shaft to pass through the shaft insertion hole of each rolling bearing fitted to the wheel,
The cylindrical portion of the collar with a collar and a cylindrical portion having a length slightly shorter than the width of the shaft insertion hole of the rolling bearing is fitted into the shaft insertion hole so that the collar portions face each other outward. And a spacer having a length equal to the interval inside the rolling bearing fitted in the bearing hole of the wheel is inserted into the support shaft and interposed inside the rolling bearing, and each rolling bearing is fitted with a collar. A caster wheel shaft support structure characterized in that it is sandwiched between a flange portion and a spacer.

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