JP6789003B2 - Wheels and casters - Google Patents

Description

The present invention relates to wheels and casters having separate inner and outer rings that can mitigate impact and noise during traveling, and further relates to wheels and casters with improved running performance and stability.

Examples of this type of wheel include those shown in Patent Document 1. In this wheel, an inner ring is arranged inside the outer ring in a state where it can be freely moved within a predetermined range including the radial direction by forming a gap in the radial direction with the outer ring, and the wheel is located at the axis of the inner ring. An axle that supports the inner ring is attached, and when the outer ring touches the ground, the inner ring is inscribed in the eccentric position of the outer ring, and the inner ring can be changed while rolling on the inner surface of the outer ring. ..

With such a configuration, the inner ring can roll inside the outer ring. Therefore, in a situation where the outer ring collides with an obstacle and locks, or smooth running is hindered, the object is continuously mounted on the inner ring through the axle. When inertia acts or an operating force is applied, the inner ring first moves forward and upward to a position where it rides on the obstacle in the outer ring, and the outer ring is slightly delayed by being urged by this inner ring. The action of climbing onto an obstacle is carried out. Therefore, it is possible to prevent the inertial force of the mounted object from acting on the wheels as a collision reaction force as it is, and to effectively prevent the generation of impact and noise. At that time, since the inner ring can be raised to a required height according to the size of the obstacle, an effective buffering action is uniformly generated except when the obstacle is extremely large.

As a result, it can be configured simply and inexpensively, alleviates the impact and noise when it collides with an obstacle while driving, effectively avoids wheel lock, and eliminates obstacles without requiring excessive operating force. It is possible to provide wheels that are easy to use and that can be overcome.

Further, as shown in Non-Patent Document 1, the present inventor has realized a new structure in which the inner ring is a twin wheel. As shown in FIG. 6, this caster is configured by arranging a pair of inner rings 102 with respect to the outer ring 101.

Japanese Unexamined Patent Publication No. 2008-13574

http://www.kamosys.com/R2/R2.html

By the way, in the case of general double-sided casters, it is customary to attach wheels to both sides of a support wall that penetrates the axle via bearings, and the support wall that holds the central part of the axle is fixed to a trolley, carry, or the like. Wheel.

However, in the inner / outer ring separation structure, when the inner ring 102 is made into twin wheels and is to be fixed to a trolley or a carry, it is necessary to fix both ends of the axle S to the trolley or the carry or the like. There is a special circumstance that it must be assembled so that it does not separate.

In FIG. 6, when the inner ring 105 is integrally provided with the outer ring 101 inside the outer ring 101 and the inner rings 102 are arranged in pairs at positions sandwiching the inner ring 105 to form a twin-wheel structure, each inner ring 102 has an inward diameter. A structure is adopted in which different boss portions 102a and 102b are provided, and these boss portions 102a and 102b are inserted into an annular gap between the outer circumference of the axle S and the inner circumference of the inner ring 105 to be fitted and integrated. doing.

However, if an overload is applied to the axle S in such a structure, the positions of the boss portions 102a and 102b may be lowered and come into contact with the inner ring 5. At first glance, such a structure seems to be a total of three-point support structure by receiving a load applied to the inner ring 5 separately from the support by the pair of bearings 104, and the support state is improved. As a result of verification by a person, the load may be concentrated on the insert-molded portion of the inner ring 5 into the outer ring 101, which may cause damage to the outer ring 101 or damage leading to the damage, and it is different to make the inner ring 102 a twin wheel. It has been found that it is desirable to maintain the arrangement of the inner rings 102, 102 in the structure.

Further, if the fitting structure of the boss portions 102a and 102b is adopted, the pair of inner rings 102 and 102 have an asymmetrical structure, so that two molds are required, which leads to an increase in cost.

Further, if the fitting structure is not adopted, the behavior of each inner ring 102 tends to be different. Therefore, in order to improve the running stability, both inner rings 102 and 102 should be kept parallel and the track should be more stable. Will be required.

An object of the present invention is to provide a wheel and a caster having a new support structure from such a viewpoint.

The present invention has taken the following measures in order to achieve such an object.

That is, in the wheel of the present invention, the inner ring is arranged inside the outer ring in a state where the wheel is freed to move within a predetermined range including the radial direction by forming a gap in the radial direction with the outer ring, and the inner ring is arranged. In a structure in which a shaft hole is provided in the shaft center so that the inner ring is inscribed in an eccentric position of the outer ring and the inner ring can be changed while rolling on the inner surface of the outer ring when the outer ring touches the ground. An inner ring is provided integrally with the outer ring inside the outer ring, a pair of inner rings are arranged separately from each other at positions sandwiching the inner ring , and the inner circumferences of the pair of inner rings are supported by different bearings. By doing so, as a twin-wheel structure, the distance between the pair of inner rings is the axis of the first regulating portion that regulates the behavior in the direction in which the distance between the pair of inner rings spreads along the axis through the bearing supporting the inner ring. It is characterized by providing a second regulating portion that regulates the behavior in the direction of narrowing along the center via a bearing that supports the inner ring .

In this way, it is not necessary to fit the inner rings into a boss structure, and a sufficient gap is created between the axle and the inner circumference of the inner ring. Therefore, a concentrated load is applied from the inner ring to the outer ring to damage the outer ring. In addition to eliminating the cause, the pair of inner rings can have a symmetrical structure, so a common mold can be used, leading to cost reduction.

As a specific embodiment, the inner circumference of each inner ring is supported by a bearing, the inner circumference of the inner ring is inserted so as to be integrated with the bearing, and the bearing forms a part of the first regulation portion. The ones that have been realized can be mentioned.

Alternatively, the inner circumference of each inner ring is supported by a bearing, the inner circumference of the inner ring is inserted so as to be integrated with the bearing, and a spacer interposed between the inner side surfaces of the bearing realizes a second regulation portion. What you are doing.

In order to make the behavior of the inner ring more stable, a rail or a groove that becomes convex toward the outer circumference is provided in the central portion in the axial direction on the outer peripheral surface of each inner ring, and two corresponding locations on the inner peripheral surface of the outer ring are provided. It is desirable to provide a groove that engages with the rail or a rail that engages with the groove.

As for the inner / outer ring ratio, it is effective that the ratio of the outer diameter dimension of the inner ring to the inner diameter dimension of the outer ring is set within the range of 1: 1.2 to 1.4.

If the axle is inserted into the axle hole of the wheel as described above and both ends of the axle are supported by the caster body, the caster can be configured by appropriately assembling the wheels having the inner and outer ring separation and the inner ring twin wheel structure.

According to the present invention described above, it is possible to provide new and useful wheels and casters that can be integrally handled as an inner and outer ring separated and an inner ring twin wheel structure, and have significantly improved running performance and stability.

The perspective view of the caster which assembled the wheel which concerns on one Embodiment of this invention. The exploded perspective view of FIG. Side view of the wheel. FIG. 3 is a sectional view taken along line IV-IV in FIG. The cross-sectional view corresponding to FIG. 4 which shows the brake function of the caster. FIG. 4 is a cross-sectional view corresponding to FIG. 4 showing a conventional structure.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a caster C to which the wheel R of the present embodiment is attached, FIG. 2 is an exploded perspective view thereof, FIG. 3 is a side view of the wheel R, and FIG. 4 is a sectional view taken along line IV-IV in FIG. Is. In FIG. 4, the hatching showing the cross section is partially omitted.

The wheel R has an inner ring 2 arranged inside the outer ring 1 in a state where it can be freely moved within a predetermined range including the radial direction by forming a gap in the radial direction with the outer ring 1, and the shaft of the inner ring 2 is provided. A shaft hole 20 through which the axle S is inserted is provided at the position of the center m, and when the outer ring 1 touches the ground, the inner ring 2 is inscribed in the eccentric position of the outer ring 1 and rolls on the inner surface 10 of the outer ring 1. It is an inner / outer ring separation structure configured so that the contact position can be changed. The shaft hole 20 is formed by a boss 3, and a bearing 4 is arranged between the boss 3 and the inner ring 2.

In particular, this embodiment realizes a twin-wheel structure of the inner ring 2 in the outer ring 1, and for that purpose, it is necessary to assemble the pair of inner rings 2 and 2 so as not to be separated from the outer ring 1. Therefore, the inner ring 5 is integrally provided with the outer ring 1 at a position that divides the inside of the outer ring 1 in the axial direction m direction, and a pair of inner rings 2 and 2 are arranged on both sides of the inner ring 5. At that time, instead of fitting the inner rings 2 and 2 into a boss structure as shown in FIG. 6, a structure that can maintain parallelism at equal intervals even when separated from each other is adopted. Therefore, a first regulating unit that regulates the behavior in which the distance between the inner rings 2 and 2 spreads along the axle S with reference to a properly assembled predetermined position by using the bearing 4 that supports the inner circumference of the inner ring 2. An X and a second regulation unit Y that regulates the behavior in which the distance between the inner wheels 2 and 2 narrows along the axle S are provided. The bisected position is not necessarily limited to the bisected position.

Specifically, the outer ring 1 has a donut shape, and the outer circumference is provided with R portions 12 having rounded corners on both sides of the flat surface 11, and the material is suitable for rolling on the road surface, for example, EPDM. Is used.

The bearing 4 uses a well-known rolling bearing having a structure in which a ball 41, which is a rolling element, is sandwiched between an inner raceway ring 42 and an outer raceway ring 43 and integrated, and a mounting hole 42a penetrates the inner raceway ring 42. doing.

On the other hand, since the inner ring 2 rolls on the inner surface 10 of the outer ring 1 while being supported by the bearing 4, a material having excellent mechanical strength, for example, PA66 (so-called 6-6 nylon) is used. The inner ring 2 has an outer peripheral portion 22 extending in a T-shaped cross section on the outer side of a disk portion 21 provided with lightening at equiangular positions, and the outer surface 22a of the outer peripheral portion 22 is used as a rolling surface and an inner circumference. It is a resin integrated body provided with an inward U-shaped insertion portion 23 on the side. The insertion portion 23 is inserted to a position that does not interfere with the function of the bearing 4 while holding both end faces of the outer raceway ring 43 of the bearing 4, and is integrated with the outer raceway ring 43.

For the inner ring 5, for example, PA66 is used as the material in order to impart the same mechanical strength as the inner ring 2. The inner ring 5 has an outer peripheral portion 52 extending in a T-shaped cross section on the outer peripheral side of the disk portion 51 provided with lightening at equiangular positions, and the outer peripheral portion 52 and a part of the disk portion 51 are inside the outer ring 1. It is integrally molded with resin (insert molding) together with the outer ring 1 in a state of being embedded in.

The boss 3 has a first cylinder portion 31 having an outer diameter that fits into the mounting hole 42a of the bearing 4, a second cylinder portion 32 having a diameter slightly larger than that of the first cylinder portion 31, and the second cylinder portion 32. The flange portion 33, which is expanded and provided at one end, is integrally molded with resin, and a step portion 34 is formed at the boundary between the first cylinder portion 31 and the second cylinder portion 32.

By setting the inner diameter φ1 of the outer ring 1 to be larger than the outer diameter φ2 of the inner ring 2, a gap is formed in the radial direction between the outer ring 1 and the inner ring 2, and the outer ring 1 is relative to the inner ring 2. In the state of FIG. 3 which is relatively eccentric upward, a crescent-shaped gap Δ is formed between the outer ring 1 and the inner ring 2. The inner circumference 53 of the inner ring 5 extends toward the axis m side of the crescent-shaped gap Δ to prevent the inner rings 2 and 2 from falling over.

The inner diameter φ1 of the outer ring 1 and the outer diameter φ2 of the inner ring 2 may be set to appropriate dimensions, but if they are too close to each other, the significance of providing the outer and inner rings 1 and 2 is lost, and conversely, if they are too far apart, they are on the road surface. I will kick the step of. As a result of various experiments by the present inventor, it is effective to keep the ratio of φ2 and φ1 φ2: φ1 in the range of 1: 1.2 to 1.4 in order to smoothly ride on a step. found.

As an example of assembly, the insertion portion 23 of the inner ring 2 is inserted into the outer raceway ring 43 of the bearing 4 so as to be integrated, and the boss 3 is inserted into the mounting hole 42a of the inner raceway ring 42 of the bearing 4 to form a stepped portion. The inner ring unit is assembled by inserting the 34 until it hits the side end surface of the inner raceway ring 42. Then, the inner ring unit is charged from the left and right into the spaces on both sides defined by the inner ring 5 inside the outer ring 1. At that time, a bush 6 which is a spacer fitted to the outer circumference of the boss 3 is positioned between the pair of bearings 4 and 4. The bush 6 used in this embodiment is made of resin and is positioned between the inner side surfaces of the inner raceway ring 42 so as not to hinder the rotation of the bearing 4. Of course, the material may be other than resin.

In such a state, an engaging portion X functioning as the first regulating portion of the present invention is formed at a position where the outer surface of the inner race ring 42 of the bearing 4 abuts on the stepped portion 34 of the boss 3, and this engaging portion X is formed. Part X regulates the behavior in which the distance between the bearings 4 and 4 expands along the axis m, and as a result, the distance between the inner rings 2 and 2 fitted to the bearing 4 also regulates to expand along the axis m. Will be done. Further, a bush 6 interposed between the inner side surfaces of the inner raceway ring 42 of the bearing 4 functions as a second regulation portion Y of the present invention, and the bush 6 causes the distance between the bearings 4 and 4 to be along the axis m. The narrowing behavior is regulated, and as a result, the distance between the inner rings 2 and 2 fitted to the bearing 4 is also regulated to be narrowed along the axis m.

Further, the pair of inner rings 2 and 2 on the inner surface 10 of the outer ring 1 are gently convex toward the outer periphery toward the central portion in the axial center m direction on the outer peripheral surfaces 22a of the inner rings 2 and 2 so as to roll on a stable track. The rail 22m is provided so as to orbit, and a groove 10m that engages with the rail 22m is provided so as to orbit at two corresponding locations on the inner surface 10 of the outer ring 1. Of course, even if a groove that is gently concave toward the outer circumference is provided in the central portion of the outer peripheral surface 22a of each inner ring 2 in the axial direction m direction, and a rail that engages with the groove is provided at two corresponding locations on the inner surface 10 of the outer ring 1. I do not care.

Finally, by inserting a bolt-shaped axle S into the shaft hole 20 and tightening the tip with a nut (not shown), the bush 6 of the boss 3 is stretched between the inner side surfaces of the inner raceway ring 42 constituting the bearing 4. The step portion 34 is tightened in a state where it abuts on the outer surface of the inner raceway ring 42 constituting the bearing 4. At this time, if the wheel A is positioned between the pair of left and right brackets 71 and 71 of the caster body 7 shown in FIG. 1 and the brackets 71 and 71 are fastened together, the wheel R is attached to the caster body 7 and finished as a caster C. .. The bracket 71 maintains a state in which the flanges 33 of the left and right bosses 3 shown in FIG. 4 are tightened from the left and right.

In this state, the pair of inner rings 2 and 2 are guided by the groove 10 m of the outer ring 1 with the rail 22 m and roll stably in the axial direction m without rattling, and the outer peripheral portion 22 of the inner ring 2 and the disk portion of the inner ring 5 A predetermined clearance δ is secured between the 51 and the 51.

The behavior when the wheel A travels on the road surface is basically the same as in Patent Document 1, and since the inner ring 2 can roll inside the outer ring 1, the outer ring 1 collides with an obstacle and locks. However, in a situation where smooth running is hindered, if the inertia of the mounted object continues to act on the inner ring 2 through the axle S, or if an operating force is applied, the inner ring 2 first enters the outer ring 1 as an obstacle. It moves forward and upward to a position where it rides up, and the outer ring 1 rolls on the inner surface 10 of the outer ring 1 with a slight delay so as to be urged by the inner ring 2, and rides on an obstacle. Therefore, it is possible to prevent the inertial force of the mounted object from acting on the wheel R as a collision reaction force as it is, and to effectively prevent the generation of impact and noise. At that time, since the inner ring 2 can be raised to a required height according to the size of the obstacle, an effective buffering action is uniformly generated except when the obstacle is extremely large.

When descending from an obstacle, the outer ring 1 descends first, and then the inner ring 2 rolls on the inner surface 10 of the outer ring 1 with a slight delay to descend from the obstacle. Therefore, even in this case, it is possible to effectively prevent the generation of impact and noise.

FIG. 5 shows a configuration in which a brake function is applied to the caster C of FIG. 1, and has a structure in which the caster body 71 is used as a scaffold to directly press the brake pad 81 against the outer ring 1, or the bush 6 can be elastically contracted. Or by using a disc spring or the like, the inner rings 2 and 2 are forcibly narrowed from the brackets 71 on both sides via the boss 3 against the second regulating portion Y to crush the gap δ shown in FIG. It is possible to appropriately adopt a structure in which the inner ring 2 is pressed against the inner ring 5 to lock the inner ring 2.

As described above, in the wheel R of the present embodiment, the inner ring 2 is provided inside the outer ring 1 in a state where the wheel R is free to move within a predetermined range including the radial direction by forming a gap in the radial direction with the outer ring 1. The shaft hole 20 is provided by the boss 3 at the position of the axial center m of the inner ring 2, and when the outer ring 1 touches the ground, the inner ring 2 is inscribed in the eccentric position of the outer ring 1 and rolls on the inner surface 10 of the outer ring 1. The inner ring 5 is integrally provided with the outer ring 1 inside the outer ring 1 so that the inner ring position can be changed while moving, and a pair of inner rings 2 and 2 are placed at positions sandwiching the inner ring 5 with each other. It has a twin-wheel structure by arranging them separately. Then, the first regulating unit X that regulates the behavior that the distance between the inner rings 2 and 2 spreads along the axis m and the second that regulates the behavior that the distance between the inner rings 2 and 2 narrows along the axis m. The regulation section Y is provided.

In this way, it is not necessary to fit the inner rings 2 and 2 into a boss structure, and a sufficient gap is created between the axle S and the inner circumference 53 of the inner ring 5. Therefore, at the center between the bearings 4 and 4. In addition to eliminating the problem that a concentrated load is applied from the inner ring 5 to the outer ring 1 and causing damage to the outer ring 1, the pair of inner rings 2 and 2 can have a symmetrical structure, so that a common mold can be used and the cost is increased. You can try to go down.

Specifically, the inner circumference of each inner ring 2 is supported by the bearing 4, and the insertion portion 23 provided on the inner circumference of the inner ring 2 is integrated with the outer raceway ring 43 of the bearing 4 without hindering the rotation. As a result, the inner raceway ring 42 of the bearing 4 forms a part of the first regulation portion X, and the inner ring 2 is integrally inserted into the bearing 4, so that the inner ring 2 A structure in which the behavior of spreading along the axle S is regulated even at two intervals is preferably realized.

Alternatively, the inner circumference of each inner ring 2 is supported by the bearing 4, and the insertion portion 23 provided on the inner circumference of the inner ring 2 is inserted into the outer raceway ring 43 of the bearing 4 so as to be integrated without hindering rotation. At the same time, the second regulation portion Y is realized by the spacer bush 6 interposed between the inner side surfaces of the inner raceway wheels 42 constituting the bearing 4 in a state that does not hinder the rotation, and the bearings 4 and 4 are spaced apart from each other. Since the behavior of narrowing along the inner ring 2 is regulated by the bush 6 and the inner ring 2 is integrally inserted into the bearing 4, as a result, the behavior of narrowing the distance between the inner rings 2 and 2 along the axis m is regulated. Is preferably realized. In particular, by fitting the bush 6 tightly to the boss 3, the effect of integrating the inner rings 2 and 2 without rattling is produced.

In addition, a rail 22m that is convex toward the outer circumference is provided at the center of the outer peripheral surface 22a of each inner ring 2 in the axial direction m direction, and a groove 10m that engages with the rail 22m is provided at two corresponding locations on the inner surface 10 of the outer ring 1. Since the inner ring 2 is provided, the track of each inner ring 2 is stable, and the pair of inner rings 2 and 2 are engaged with the groove 10 m of the common outer ring 1 to serve as the first regulating portion X and the second regulating portion Y. The behavior of the inner ring 2 will be more stable.

Further, since the ratio of the outer diameter dimension φ2 of the inner ring 2 to the inner diameter dimension φ1 of the outer ring 1 is set within the range of 1: 1.2 to 1.4, the step climbing function is extremely good.

Then, by inserting the axle S into the shaft hole 20 of the wheel R configured as described above and supporting both ends of the axle S by the caster main body 7, the wheels 2 having the inner and outer ring separation and the inner ring twin wheel structure can be appropriately assembled. It is possible to configure the caster C.

Although one embodiment of the present invention has been described above, the specific configuration and materials of each part are not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. is there.

For example, the inner ring 5 and the outer ring 1 are not necessarily integrally molded, but may be molded separately and integrated or integrally connected.

Further, in the above embodiment, the boss is pressed against the inner raceway ring of the bearing to form the first regulation portion that regulates the behavior of widening the inner ring spacing. However, when the boss is not used, the inner raceway ring of the bearing is outside. The same effect can be achieved by making the inner race wheel wider than the race wheel so that the regulating force acts directly on the inner race wheel.

Further, in the above-described embodiment, the structure in which the outer ring is a single wheel and the inner ring is a twin wheel has been described. However, the outer ring is also a twin wheel, and the inner ring is arranged inside each outer ring, and the inner ring is integrated with each outer ring between these inner rings. Even if the inner ring is positioned, wheels and casters according to the above embodiment can be configured. In this case, a holding plate having a diameter larger than the inner diameter of the inner ring is arranged between the inner rings and passed through the axle to prevent both ends of the axle from coming off, and the axle is supported by the caster body between the holding plates. For example, the outer ring can be properly held.

The wheels and casters of the present invention can be used for trolleys, carries, carts, wheelbarrows, vehicles, and various consumer products and industrial machines that are required to travel over bumps and obstacles on the road surface. it can.

1 ... Outer ring 2 ... Inner ring 3 ... Boss 4 ... Bearing 5 ... Inner ring 6 ... Spacer (bush)
7 ... Caster body 10 ... Inner surface 10m ... Groove 20 ... Shaft hole 22m ... Rail 71 ... Bracket C ... Caster m ... Axle center R ... Wheel X ... First regulation part Y ... Second regulation part

Claims (6)

The inner ring is arranged inside the outer ring in a state where it can be freely moved within a predetermined range including the radial direction by forming a gap in the radial direction with the outer ring, and a shaft hole is provided in the axial center of the inner ring. In the case where the inner ring is inscribed in the eccentric position of the outer ring and the inner ring can be changed while rolling on the inner surface of the outer ring when the outer ring touches the ground.
An inner ring is provided integrally with the outer ring inside the outer ring, a pair of inner rings are arranged separately from each other at a position sandwiching the inner ring , and the inner circumferences of the pair of inner rings are supported by different bearings. As a result, as a twin-wheel structure, the distance between the pair of inner rings is the axis of the first regulating portion that regulates the behavior in the direction in which the distance between the pair of inner rings spreads along the axis via the bearing supporting the inner ring. A wheel characterized by providing a second regulating portion that regulates the behavior in a narrowing direction along the inner ring via a bearing that supports the inner ring . The first aspect of claim 1, wherein the inner circumference of each inner ring is supported by a bearing, the inner circumference of the inner ring is inserted so as to be integrated with the bearing, and the bearing constitutes a part of the first regulation portion. Wheels. The inner circumference of each inner ring is supported by a bearing, and the inner circumference of the inner ring is inserted so as to be integrated with the bearing, and a spacer interposed between the inner side surfaces of the bearing realizes a second regulation portion. The wheel according to claim 1 or 2. A rail or a groove that is convex toward the outer circumference is provided at the center of the outer peripheral surface of each inner ring in the axial direction, and a groove that engages with the rail or the groove is provided at two corresponding locations on the inner peripheral surface of the outer ring. The wheel according to any one of claims 1 to 3, which is provided with an engaging rail. The wheel according to claim 1, wherein the ratio of the outer diameter dimension of the inner ring to the inner diameter dimension of the outer ring is set within the range of 1: 1.2 to 1.4. A caster according to any one of claims 1 to 5, wherein the axle is inserted into the shaft hole of the wheel so that both ends of the axle are supported by the caster body.

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