TECHNICAL FIELD

The present invention relates to a seal member for a ball transfer capable of being utilized in a splitter platform or the like such as will permit a conveyed object that is placed onto a location covered with a plurality of ball transfers at a distribution line or the like to move in other direction(s), and to a ball transfer employing said seal member for a ball transfer.

BACKGROUND ART

Ball transfers are employed in equipment for facilitating movement of conveyed objects in distribution lines and the like. When a conveyed object is placed onto ball transfers at a location covered with a plurality of ball transfers, because balls arranged so as to be capable of rotating freely in any direction at the sockets of the respective ball transfers support the conveyed object via point contact, causing movement in other direction(s) to be greatly facilitated, they are in general use in splitter platforms and so forth for conveyed objects.

Because movement of conveyed objects is permitted thereby, entry of foreign objects originating from such conveyed objects and/or the like into the interior of the socket or the like of a ball transfer will interfere with rotation of the ball, which will constitute an impediment to the movement of the conveyed objects. For this reason, to prevent entry of foreign objects into the interior of the socket or the like of a ball transfer, devices employing seal members such as metal seals, felt, rubber seals, and resin seals have conventionally been manufactured and sold. Furthermore, it has also been proposed to employ a device in which a support-ball-restraining ring that increases the rotational resistance of the primary ball is used to suppress scattering of particles from socket recessed locations (see Patent Reference No. 1). However, not only is the structure of the proposed device complicated, but as a structure different from that of the conventional device would have to be provided at the interior of the ball transfer, and as a new die and so forth would be necessary, it would result in increased manufacturing cost.

PRIOR ART REFERENCES

Patent References

Patent Reference No. 1: Japanese Patent Application Publication Kokai No. 2012-21556

SUMMARY OF INVENTION

Problem to be Solved by Invention

Conventional ball transfers have employed a metal seal, felt, rubber seal, or resin seal as seal member to prevent entry of foreign objects thereinto from the exterior of the ball transfer. Such seal members as have been employed conventionally have been widely employed, and have, with respect to entry of foreign objects, generally provided effectiveness with respect thereto. However, upon carrying out a detailed investigation and study of ball transfers employing such seal members of the conventional type, it became clear to the Applicant that, apart from what might be said regarding entry of foreign objects, these had a variety of problems.

At ball transfers employing seal members of the metal type, not only was there generation of particulate due to wear as a result of the rolling occurring between the small balls and the large ball due to contact at the seal member and the large ball, but wear also caused generation of metal particulate that was peculiar to the seal member. In addition, it was learned that such particulate due to wear which was produced caused abrasion of the small balls and the large ball and was a factor in shortening the life of the ball transfer, and it was realized that there was a need to suppress generation of such particulate due to wear and to prevent ball wear. Furthermore, as mutual sliding of metal causes generation of a loud and unpleasant metallic sound, the environments in which these may be used are limited. For this reason, there has been demand for improvement from users who desire low-noise characteristics. One means for achieving low-noise characteristics that has been contemplated is use of a large ball made of resin. However, where resin is used as the material of the ball, due to the difference in hardness therebetween, the metal-type seal member will cause abrasion of the large ball made of resin, such that there will be substantial and rapid wear of the ball. This being the case, where a ball transfer which employs a large ball made of resin is used, as it will not be possible to use a metal seal, it will not be possible for this to be used at a site where foreign objects are present.

At ball transfers employing seal members of the felt type, to ensure adequate seal characteristics it was necessary to employ a large lip width, and to in addition cause this to be pressed against the large ball with considerable force. For this reason, because it is inescapable that frictional resistance will be high, there has been the problem that operability tends to be affected by the increase in drag. To address this, there have been attempts to improve operability by suppressing frictional resistance by causing the felt to be impregnated in advance with lubricating oil so as to suppress frictional resistance. However, upon carrying out detailed investigation and study, it was found when used for an extended period that frictional resistance increases as a result of the fact that the lubricating oil is used up, and furthermore that to the extent that the seal member has been made to press against the large ball with considerable force, there is a tendency for sliding due to rotation to cause the seal member to deform and there is a tendency for seal function to deteriorate. Furthermore, because lubricating oil adheres to the large ball, the range of conditions over which it can be used is limited. It being, practically speaking, difficult, at a point in time when the lubricating oil with which the felt was impregnated is used up or at a point in time prior thereto, to, while the ball transfer is in the process of being used and without disassembling the ball transfer, cause it to be wetted with an appropriate amount of lubricating oil and prevent deformation of the seal member or restore it to its original shape, further improvements have been sought with respect thereto.

At ball transfers employing seal members having rubber seals, it was found that frictional resistance increases because a nip is formed when the rubber of the seal member comes in contact with the large ball. Furthermore, when the large ball rolls at high speed, the fact that the rubber seal vibrates and is lifted up causes it to wrap about the large ball, and because the seal member becomes sandwiched in the gap between it and the case, rolling resistance becomes extremely high. In addition, it was determined that if this is continued to be used while in this state, the rubber of the seal member suffers damage and stops functioning as a seal. Furthermore, it was determined that there were problems whereby vibration of the rubber caused generation of a fluttering sound and whereby noise was produced during rotation of the large ball, these being issues that ought to be improved.

At ball transfers employing seal members having resin seals, where the large ball in contact therewith is a metal ball, there is a problem whereby there will be occurrence of abrasion at the seal member due to the difference in hardness therebetween, as a result of which usage thereof is limited to situations in which the large ball is made of resin. However, to prevent static electricity and wear due to mutual contact and friction between resinous bodies, there have also been restrictions with respect to the permitted combinations of seal members and balls, as a result of which there has been a reduction in the degrees of freedom available during design thereof, improvement with respect to which is required. Furthermore, it was found that particulate produced as a result of abrasion of resin accumulates at the interior of the ball transfer, and that mixture thereof with particulate produced due to wear as a result of rotation of the large ball and the small balls results in a sludge-like mass that sticks and adheres to the surfaces of the small balls, as a result of which there is greater deterioration of the small balls, which is a factor in causing a decrease in the life of the ball transfer, improvement with respect to which is required.

It was thus learned that while conventional seal members for ball transfers such as metal seals, felt, rubber seals, and resin seals possess basic ball transfer performance by which entry of foreign objects thereinto is prevented, it was observed that with continuous use of such ball transfers there were a wide variety of disadvantages which included increase in frictional resistance, increase in noise, loss of seal characteristics, and wear not only of the small balls but also of the other respective members, improvement with respect to which is required.

Moreover, because seal members of the conventional type such as metal seals, rubber seals, and resin seals were inferior with respect to ability to conform to the case, dies of precise dimensional accuracy being required for provision of adequate sealing effect, this was a factor in causing increase in manufacturing cost. Furthermore, where product shape and/or dimensions of the ball transfer itself are to be changed, with a conventional seal member such as a rubber seal or a resin seal for a ball transfer, it has been necessary to fabricate a new die for molding of the rubber seal or resin seal to accommodate the change in product shape and/or dimensions of the ball transfer, which has been a factor in causing increase in manufacturing cost, and it has also been the case that there have been few degrees of freedom at times when the design is to be changed, and the speed with which changes in design could be accommodated has been low. Improvement has also been sought with respect to such issues.

A problem to be solved by the invention under application is to therefore provide a novel seal member for a ball transfer which possesses basic performance by which entry of foreign objects into the interior of the ball transfer is prevented, without requiring a change in product shape and/or dimensions of the conventional ball transfer itself. In addition, a further problem to be solved by the invention under application is to, in addition to the aforesaid basic performance, even in situations in which the ball transfer is used continuously for a long period of time, permit the basic performance by which entry of foreign objects into the interior of the ball transfer is prevented to be maintained, and prevent generation and accumulation of particulate due to wear at the interior of the ball transfer, or leakage of particulate due to wear to the exterior of the ball transfer, and achieve increased product life. Furthermore, a further problem to be solved by the invention under application is to improve sound prevention characteristics during use in situations in which the ball transfer is used continuously for a long period of time. Moreover, a problem to be solved by the invention under application is to provide a novel seal member for a ball transfer and a ball transfer employing same that are capable of solving the foregoing problems without requiring a change in the shape of ball transfers that have come to be used conventionally.

Means for Solving Problem

A first mean s in accordance with the present invention for solving the foregoing problems is a seal member for a ball transfer1characterized in that it has a seal member employing pile fiber1athat, at a ball transfer100having a main body which has a socket101, an inner surface of which is a hemispherical concave surface102a, a plurality of ball bearings103arranged at the main body socket, a primary ball104, diameter of which is greater than that of said ball bearings and which is rotatably supported by the socket by way of the ball bearings, and a housing-like case105which surrounds the main body socket and rotatably supports the ball bearings and the primary ball at a bearing portion thereof and which has a hole from which a portion of the primary ball is made to protrude at an upper surface of the primary ball socket, is arranged such that, at a space formed between the housing-like case and the primary ball and the main body106, a fiber tip portion is bent so as to occlude a gap between said primary ball and said housing-like case107and cause said fiber tip portion to abut the primary ball; and an adhesive member for causing adhesion between the seal member comprising pile and the housing-like case. As the adhesive member1b, any desired substance may be used so long as it is adhesive that is ordinarily used for pile base fabric adhesion. Furthermore, double-sided adhesive tape or adhesive tape at which adhesive has been applied to the substrate thereof may be used.

A second means in accordance with the present invention is the seal member for the ball transfer1according to first means characterized in that the pile fiber of the seal member is cut pile.

A third means in accordance with the present invention is the seal member for the ball transfer1according to any one of the first or the second means characterized in that the cut-pile pile fiber consists of crimped multifilament fiber. The pile fiber1cof the cut pile employed in this seal member might be crimped high-density pile comprising multifilament employing filament made of acrylic/polyester-type fiber of modified cross-section such that the outside circumference is split after the fashion of a “*”-like shape. Furthermore, besides “*”-like shape, the cross-sections of the respective filaments of the crimped pile fiber might moreover be of star-like shape or circular cross-section, or might be of hollow cross-section or other such modified cross-section, a cross-sectional shape such as will cause there to be increased surface area being preferred.

For the cut-pile pile fiber consisting of crimped multifilament fiber, reference can be made to the description and figure of a “woven structure peripheral to a cut-pile ground yarn portion of a shaft seal (t-type)” in US2019/0017544A1. The “woven structure peripheral to a cut-pile ground yarn portion of a shaft seal (t-type)” has a configuration consisting of base1e, front lining warp yarn1f, front weft yarn1g, back lining warp yarn1h, and back weft yarn pile fiber1j.

A fourth means in accordance with the present invention is the seal member for the ball transfer1according to any one of the first through third means characterized in that cut pile comprises woven fabric.

A fifth means in accordance with the present invention is the seal member for the ball transfer1according to any one of the first through third means characterized in that cut pile comprises knit fabric.

A sixth means in accordance with the present invention is a ball transfer100characterized in that, at the ball transfer having the main body101which has the socket102, the inner surface of which is the hemispherical concave surface102a, the plurality of ball bearings103arranged at the main body socket, the primary ball, diameter of which is greater than that of said ball bearings and which is rotatably supported by the socket by way of the ball bearings, and the housing-like case105which surrounds the main body socket and rotatably supports the ball bearings and the primary ball at the bearing portion thereof and which has the hole from which the portion of the primary ball is made to protrude at the upper surface of the primary ball socket, the seal member for the ball transfer according to any one of the first through the fifth means is arranged such that, at the space formed between the housing-like case and the primary ball and the main body106, the fiber tip portion is bent so as to occlude the gap between said primary ball and said housing-like case107and cause said fiber tip portion to abut the primary ball, the seal member for said ball transfer being made to adhere to the housing-like case by the adhesive member for causing adhesion between the seal member comprising the pile and the housing-like case.

BENEFIT OF INVENTION

Because seal members in conventional products which are metal seals, felt, rubber seals, and resin seals are all such that particulate produced by wear due to rolling contact between the large ball and the small balls and the small balls and the case is scraped away therefrom by such seal members, particulate due to wear accumulates at the interior. However, the foregoing means for solving the problems in accordance with the present invention are such that, by causing a seal member thereof to be arranged so as to cause high-density pile comprising fine fibers to come in contact with the large ball toward the interior of the case, it is possible to provide the benefit whereby the particulate due to wear that adheres to the large ball is made to cling to the pile and is quickly removed therefrom. As a result, the situation in which particulate due to wear remains and causes further wear of the small balls is eliminated. In addition, not only does this contribute to increased product life, but it also makes it possible to obtain the benefit whereby sound prevention characteristics during use are greatly improved.

Furthermore, the foregoing means for solving the problems in accordance with the present invention are such that thickness of that pile seal member is small, and length of the pile fibers can be controlled. And with respect to adhesion of the pile seal member used in the present invention to the case, it is possible to make use of the location that has served as gap until now, i.e., such gap as is produced by the locus required to prevent the large ball from becoming dislodged and as is structurally necessary for it to serve in its role as a ball transfer or such gap as is produced by the portion where a flange is to be attached to prevent scattering of the small balls, as the installation site for the pile seal member, it being possible for adhesion to be carried out at said site such that there is no inefficiency as a result of thereof. For this reason, the foregoing means for solving the problems in accordance with the present invention are such that it is possible to provide a novel ball transfer at which a pile seal member in accordance with the present invention is installed, without the need to manufacture a new die, and without the need to change the shape of the case that has been used conventionally.

Furthermore, where product shape and/or dimensions of the ball transfer itself are to be changed, with a conventional seal member such as a rubber seal or a resin seal for a ball transfer, it has been necessary to fabricate a new die for molding of the rubber seal or resin seal to accommodate the change in product shape and/or dimensions of the ball transfer, which has been a factor in causing increase in manufacturing cost. Furthermore, it has also been the case that there have been few degrees of freedom at times when the design is to be changed, and the speed with which changes in design could be accommodated has been low. However, the pile seal members in accordance with the means of the present invention are such that they provide a wide variety of extremely excellent benefits, such as the fact that because they do not require an expensive die but can be accommodated by merely fabricating an extremely inexpensive punching die for pile fabric, mass production thereof is possible and they permit great benefit in terms of cost reduction; and moreover, they permit many degrees of freedom at times when the design is to be changed, and they are such that the speed with which changes in design can be accommodated is high.

In addition, because seal members of the conventional type such as metal seals, felt, rubber seals, and resin seals have been inferior with respect to ability to conform to the case, precise dimensional accuracy has been required for provision of adequate sealing effect. However, the foregoing means for solving the problems in accordance with the present invention are such that because that pile seal member is woven fabric, ability to conform to the case is very good. For this reason, as compared with other seal members of the conventional type such as metal seals, felt, rubber seals, and resin seals, it does not require precise dimensional accuracy, and it is also extremely easy to assemble.

