JP2003072307A - Caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a caster in compact constitution. SOLUTION: A cylindrically formed inner ring 14 is supported free to revolve through a rolling element 18 on the inside of a cylindrical formed outer ring 12. A wheel 16 is supported free to rotate at a position eccentric against an axis of rotation θ of the inner ring 14 on the inside of the inner ring 14. Consequently, it is possible to provide the caster 10 which is limited in total height and is compact.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a caster,
In particular, the present invention relates to a caster that is attached to the bottom of an article and movably supports the article.

[0002]

2. Description of the Related Art Conventionally, in this type of caster, as shown in FIG. 12, a rotary shaft 3 is mounted on an upper portion of a support frame 2 for supporting a wheel 1, and the rotary shaft 3 is mounted on a base 5 to form a bearing 4. It is configured to be supported by.

[0003]

However, since the conventional caster has a structure in which the rotating shaft 3 is attached to the upper portion of the support frame 2, the height of the caster as a whole is increased, and the article to which the caster is attached is increased. The disadvantage is that the height of the

Further, since the moment load is large and the load generated in the bearing 4 is large, there is a drawback that a large load cannot be accommodated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a caster having a compact structure and capable of handling a large load.

[0006]

In order to achieve the above object, the present invention provides an outer ring, an inner ring rotatably supported by an inner peripheral portion of the outer ring, and an inner ring housed inside the inner ring. And a wheel that is arranged eccentrically with respect to the center of rotation of the caster.

According to the present invention, since the wheel is housed inside the inner ring rotatably supported on the inner peripheral portion of the outer ring, the overall height does not increase and the structure becomes compact. Moreover, since no harmful moment is generated, it is possible to handle a large load.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a caster according to the present invention will be described below in detail with reference to the accompanying drawings.

1 and 2 are a side view and a bottom view, respectively, of a first embodiment of a caster according to the present invention. 3 is a sectional view taken along line 3-3 of FIG.

As shown in the figure, the caster 10 of the present embodiment comprises an outer ring 12, an inner ring 14 and wheels 16.

The outer ring 12 is formed in a cylindrical shape, and its upper portion is covered with a cover 12A. A plurality of mounting holes 12a, 12a, ... Are formed in the cover 12A, and the caster 10 has the mounting holes 12a, 12a ,.
Are screwed to the target article through bolts 13, 13 ,.

The inner ring 14 is formed in a cylindrical shape and is rotatably supported inside the outer ring 12 via a large number of rolling elements 18, 18 ,.

The rolling elements 18, 18, ... Are spherically formed, and have a semicircular cross section formed on the inner peripheral surface of the outer ring 12 and a semicircular cross section formed on the outer peripheral surface of the inner ring 14. The inner ring 14 is rotatably supported with respect to the outer ring 12 by being fitted in the groove 22.

Inside the inner ring 14, a pair of ribs 24, 24 is provided.
Are arranged in parallel with a predetermined width. This rib 2
Bearing holes 26, 26 are horizontally formed in the bearings 4, 24 at positions eccentric with respect to the center of rotation (rotational axis) θ of the inner ring 14. The shaft 16 of the wheel 16 is fitted into the bearing holes 26, 26 and is axially supported.

The caster 10 of this embodiment is constructed as described above. FIG. 4 is a caster 1 of this embodiment.
An example of attachment when 0 is attached to the leg portion 6 of the chair is shown. As shown in the figure, the caster 10 is attached to the lower end of the tip of each leg member 7, 7, 7 that constitutes the leg portion 6 of the chair.

At this time, each caster 10 has its outer ring 1
The cover 12A formed on the upper part of 2 is screwed to the base 8 attached to the tip of the leg member 7 with bolts 13, 13 ,.

Caster 1 mounted as described above
At 0, each wheel 16 rolls on the installation surface to movably support the chair. Then, the caster 10 has wheels 16
Is installed eccentrically with respect to the rotation axis θ of the inner ring 14, so that the chair can be moved in any direction. That is, when the caster 10 receives a force in a direction different from the rolling direction of the wheel 16, the caster 10 moves in the direction in which the force is received.
Since the inner ring 14 rotates so that 6 faces, it can be moved in any direction by 360 degrees.

Further, the caster 10 of this embodiment is
Since the wheel 16 is housed inside the inner ring 14, the overall height can be reduced, and the configuration can be extremely compact. Further, this prevents the article to which the caster 10 is attached from becoming higher than necessary.

Further, according to the caster 10 of the present embodiment, since no harmful moment is generated, it is possible to cope with a large load.

FIG. 5 is a vertical sectional view of a second embodiment of the caster according to the present invention. As shown in the figure, the caster 10 'of the present embodiment differs from the caster 10 of the first embodiment described above in the configuration of the outer ring 12'. The same members as those of the caster of the first embodiment are designated by the same reference numerals.

That is, the outer ring 12 'is formed in a cylindrical shape having an open upper portion, and the flange 1 is formed on the outer periphery of the upper end portion.
2B is formed. The flange 12B has a plurality of mounting holes 12b, 12b, ...
The caster 10 is screwed to the target article by passing bolts 13, 13, ... Through the mounting holes 12b, 12b ,.

With this structure, the overall height can be further reduced, and the structure can be made more compact.

FIGS. 6 and 7 are a vertical sectional view and a bottom view, respectively, of a third embodiment of a caster according to the present invention.

As shown in the figure, the caster 30 of the present embodiment comprises a housing 32, an outer ring 34, an inner ring 36 and wheels 38.

The housing 32 is formed in a disk shape, and a ring-shaped mounting frame 40 is integrally formed on the lower surface coaxially therewith.

The outer ring 34 is formed in a cylindrical shape, and is fitted and fixed inside the mounting frame 40 formed in the housing 32.

The inner ring 36 is formed in a disk shape and is fitted inside the outer ring 34. The inner ring 36 is rotatably supported inside the outer ring 34 via a large number of rolling elements 42, 42, .... The rolling elements 42, 42, ... Are formed in a spherical shape and have a semicircular cross section groove 44 formed on the inner peripheral surface of the outer ring 34 and a semicircular cross section groove 46 formed on the outer peripheral surface of the inner ring 36. The inner ring 36 and the outer ring 34.
It is rotatably supported with respect to.

The wheel 38 is formed in a spherical shape, and the inner ring 3
It is housed in a recess 48 formed in the lower end surface of the member 6.
The recess 48 is formed in a hemispherical shape, and is formed at a position eccentric with respect to the rotation center (rotation axis) θ of the inner ring 36. The wheel 38 has a large number of rolling elements 5 in the recess 48.
It is accommodated via 0, 50, .... Then, a part thereof projects from the lower end surface of the inner ring 36. Rolling element 50,
The wheels 50 and the concave portion 4 are formed in a spherical shape.
8 is interposed. A ring-shaped retaining ring 52 is attached to the lower end opening of the recess 48,
The wheels 38 and the rolling elements 50, 50, ...
It is locked to and is prevented from falling off.

In the caster 30 of the present embodiment configured as described above, the wheels 38 are installed eccentrically with respect to the rotation axis θ of the inner ring 36 as in the caster 10 of the first embodiment described above. Therefore, the attached article can be moved in any direction.

Further, similarly to the caster 10 of the first embodiment described above, since the wheel 38 is housed in the recess 48 formed in the lower end surface of the inner ring 36, the overall height can be reduced and the size is extremely compact. It can be configured. Further, this prevents the article to which the casters 30 are attached from becoming unnecessarily high.

8 and 9 are a vertical sectional view and a bottom view, respectively, of a caster according to a fourth embodiment of the present invention.

As shown in the figure, the caster 60 of this embodiment is composed of a housing 62, an outer ring 64, an inner ring 66 and wheels 68.

The housing 62 is formed in a disk shape, and a ring-shaped mounting frame 70 is integrally formed on the lower surface coaxially therewith.

The outer ring 64 is formed in a cylindrical shape, and is fitted and fixed inside the mounting frame 70 formed in the housing 62.

The inner ring 66 is formed in a disk shape and is fitted inside the outer ring 64. The inner ring 66 is rotatably supported inside the outer ring 64 via a large number of rolling elements 72, 72, .... The rolling elements 72, 72, ... Are formed in a spherical shape and have a pair of upper and lower grooves 74, 74 having a semicircular cross section formed on the inner peripheral surface of the outer ring 64 and a half cross section formed on the outer peripheral surface of the inner ring 66. The inner ring 66 is rotatably supported with respect to the outer ring 64 by being fitted into a pair of upper and lower circular grooves 76, 76.

The wheel 68 is formed in the shape of a roller and is housed in a recess 78 formed in the lower end surface of the inner ring 66. The recess 78 has a semicircular cross section, and is formed at a position eccentric with respect to the rotation center (rotation axis) θ of the inner ring 66. The wheel 68 is accommodated in the recess 78 through a large number of rolling elements 80, 80, ... And is arranged so that its rotation axis λ is orthogonal to the rotation axis θ of the inner ring 66. Then, a part thereof projects from the lower end surface of the inner ring 66. The rolling elements 80, 80, ... Are formed in a cylindrical shape and are interposed between the outer peripheral surface of the wheel 68 and the inner peripheral surface of the recess 78. Further, a stop frame 82 formed in a rectangular frame shape is attached to the lower end opening of the recess 78, and the wheels 68 and the rolling elements 80, 80 ,. Is prevented.

In the caster 60 of this embodiment configured as described above, the wheels 68 are installed eccentrically with respect to the rotation axis θ of the inner ring 66 as in the caster 10 of the first embodiment described above. Therefore, the attached article can be moved in any direction.

Further, like the caster 10 of the first embodiment described above, since the wheel 68 is housed in the recess 78 formed in the lower end surface of the inner ring 66, the overall height can be reduced and the size is extremely compact. It can be configured. Further, this prevents the article to which the casters 60 are attached from becoming unnecessarily high.

The caster 60 of this embodiment is
The wheel 68 is rotatably supported by the rolling elements 80, 80, ..., However, a support shaft is formed coaxially on both ends of the wheel 68,
The shaft may be supported by a bearing installed in the recess 78.

Further, the caster 60 of this embodiment is
The rolling elements 72, 72, ... Are arranged at two positions above and below between the outer ring 64 and the inner ring 66, but are arranged and supported at one position like the caster 30 of the third embodiment described above. You may do it. Similarly, the casters 10 and 30 of the first to third embodiments are the casters 6 of the fourth embodiment.
As in the case of 0, the rolling elements may be arranged and supported at two upper and lower positions between the outer ring and the inner ring.

Further, although the casters of the above-described embodiments each have one wheel, a pair of wheels may be installed at symmetrical positions.

Further, in the above-described embodiment, an example in which the caster according to the present invention is attached to the leg portion of the chair and used is explained, but the caster according to the present invention is attached to such a lightweight object for use. Not limited to the case, it can be attached to a heavy object such as a heavy machine for use.

FIG. 10 is a front view of an underground continuous wall excavator to which the casters according to the present invention are attached, and FIG. 11 is
It is a bottom view.

The underground continuous wall excavator 170 lowers the excavator main body 172 suspended by the suspension wire 176 while rotating the drum cutters 174, 174 provided in the excavator main body 172, thereby digging into the ground. It is a device for boring a slot. The hoisting wire 176 hoisting the excavator main body 172 is a hoisting device 178 installed on the ground.
The hoisting device 178 lifts the excavator main body 172 by winding the hoisting wire 176 with the hoisting device 178. The caster 10 (3 according to the present invention is attached to the carriage 180 that movably supports the lifting device 178.
0, 60) are used. That is, the lifting device 178 is installed on the pedestal 182 that constitutes the carriage 180, and six casters 10 (30, 60) according to the present invention are attached to the lower surface of the pedestal 182 (4
One is acceptable).

As described above, the caster according to the present invention can also be used when movably supporting a heavy object such as a heavy machine. In this case, the entire structure is downsized, the structure is simple, and the strength is stable.

In this case, the casters 10, 30, 60 according to the present invention may be configured to be able to travel on the rail. At this time, the casters 10, 30, 60
It is preferable to form a groove on the circumferential surface of the rail so that the rail is not derailed.

[0047]

As described above, according to the present invention, since the wheels are accommodated in the inner peripheral portion of the inner ring rotatably supported by the inner peripheral portion of the outer ring, the overall height is reduced. A compact structure can be achieved without increasing the cost. Moreover, since no harmful moment is generated, it is possible to handle a large load.

[Brief description of drawings]

FIG. 1 is a side view of a first embodiment of a caster according to the present invention.

FIG. 2 is a bottom view of the caster according to the first embodiment of the present invention.

3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a perspective view showing a configuration of a leg portion of a chair to which casters are attached.

FIG. 5 is a vertical sectional view of a second embodiment of a caster according to the present invention.

FIG. 6 is a longitudinal sectional view of a third embodiment of caster according to the present invention.

FIG. 7 is a bottom view of the caster according to the third embodiment of the present invention.

FIG. 8 is a vertical sectional view of a caster according to a fourth embodiment of the present invention.

FIG. 9 is a bottom view of the caster according to the fifth embodiment of the present invention.

FIG. 10 is a front view of an underground continuous wall excavator equipped with casters according to the present invention.

FIG. 11 is a bottom view of an underground continuous wall excavator to which casters according to the present invention are attached.

FIG. 12 is a side view showing the configuration of a conventional caster.

[Explanation of symbols]

10, 10'30, 60 ... Caster, 12, 12 ',
34, 64 ... Outer ring, 14, 36, 66 ... Inner ring, 16, 3
8, 68 ... Wheels, 18, 42, 72 ... Rolling elements, 32, 6
2 ... Housing, 170 ... Underground continuous wall excavator, 172 ...
Excavator body, 174 ... Drum cutter, 176 ... Suspension wire, 178 ... Lifting device, 180 ... Bogie, 182 ... Stand

Claims (3)

[Claims] 1. An outer ring, an inner ring rotatably supported by an inner peripheral portion of the outer ring, and a wheel housed inside the inner ring and arranged eccentrically with respect to a rotation center of the inner ring. A caster characterized by becoming. 2. The wheel is formed into a spherical shape,
The caster according to claim 1, wherein the caster is accommodated in a recess formed in the lower surface of the inner ring and is rotatably supported in a state that a part of the recess projects from the lower surface of the inner ring. 3. The wheel is formed in a roller shape, and is housed in a recess formed in the lower surface of the inner ring, and is rotatably supported while a part of the wheel is protruding from the lower surface of the inner ring. The caster according to claim 1, wherein: