The present invention is a national phase entry under 35 U.S.C. 371 of International Application No. PCT/KR2010/008883, filed on Dec. 13, 2010, which claims the benefit of Korean Patent Application No. 10-2010-0006985, filed on Jan. 26, 2010. The disclosures of said applications are incorporated by reference herein.
The present invention relates to a rubber crawler, and more particularly, to a rubber crawler having a metal core for improvement of wheel separation and durability, in which metal core extensions are formed at predetermined intervals along the lengthwise direction of the metal core of the rubber crawler so as to avoid the phenomenon of wheel separation which occurs during crawler operation and minimize lug breakage due to foreign substances and also minimize bend fatigue, metal core exposure and breakage of a tread portion, thereby enhancing the durability performance.
Generally, a crawler formed of rubber, a metal core and a steel cord is called a caterpillar track which is used as a wheel component in agricultural or industrial machineries such as a combine, a motor-lorry, an excavator and a snowplow.
The crawler enhances operation efficiency on the soft ground and also allows environmentally friendly movement and work. Particularly, the crawler is used as a substitute for a steel chain in an excavator in order to improve noise and vibration, thereby enhancing a comfortable ride.
Herein, since the metal core 5 formed into a single body has not a separate structure for reinforcing the rigidity, the whole rigidity of the crawler 1 is lowered and also the crawler 1 may be easily separated by external shock applied from the side surface, thereby causing wheel separation.
In order to solve the problem, there has been proposed a new structure of the metal core for improving the wheel separation.
In the conventional crawler for improving the wheel separation, adjacent metal core extensions 15a and 15b for preventing the wheel separation support each other against the external force generated in the transverse direction of the crawler 11. However, when the external force is simultaneously generated in the up and down direction as well as the transverse direction of the crawler 11, there is a problem that the wheel separation preventing function is not performed smoothly.
Further, in the conventional metal core structure for preventing the wheel separation, as shown in the Y portion of
Furthermore, since the metal core extensions 15a and 15b are not located completely at the internal surface of the lug 12, there is other problem of being weak in the bend fatigue, the metal core exposure due to foreign substances and the breakage of a tread portion.
An object of the present invention is to provide a rubber crawler having a metal core for improvement of wheel separation and durability, which can support a Z axis which has the largest displacement as well as X and Y axes, thereby improving the wheel separation and minimizing the Z axis displacement upon the interference of the foreign substances, and thus which can minimize the lug breakage of the crawler due to the foreign substances, thereby minimizing the wheel separation and the durability.
Another object of the present invention is to provide a rubber crawler having a metal core for improvement of wheel separation and durability, which can minimize the metal core exposure and the breakage of the tread portion due to the foreign substances and bend fatigue.
Yet another object of the present invention is to provide a rubber crawler having a metal core for improvement of wheel separation and durability, in which a thick rubber layer is formed between metal core extension and steel cord so as to absorb shock when the metal core is bent, thereby minimizing the breakage of the steel cord and the tread portion.
Yet another object of the present invention is to provide a rubber crawler having a metal core for improvement of wheel separation and durability, which has a wide external bending surface of the metal core extension so as to disperse stress locally applied when the metal core is bent, thereby minimizing the separation of the metal core and the crawler.
Yet another object of the present invention is to provide a rubber crawler having a metal core for improvement of wheel separation and durability, in which a lower surface of the metal core extension and a bottom surface of the metal core form a predetermined angle in the lengthwise direction of the crawler so as to minimize the stress generated when the metal core is bent, thereby minimizing the breakage of the steel cord and the tread portion.
To achieve the object of the present invention, the present invention provides a rubber crawler having a metal core for improvement of wheel separation and durability, including a lug which is formed to protrude on an external side surface and grounded on the ground; a steel cord which is disposed internally for enduring compressive load and driving load of a tracked vehicle; a metal core which is embedded within the steel cord so as to transfer the driving force of an engine; and metal core extensions which are embedded along both lengths on the basis of the center portion of the metal core so as to prevent wheel separation of the metal core, wherein mutually opposite surfaces of the metal core extensions are inclined at a predetermined angle, and surfaces of overlapped portions (center portions) of the metal core extensions are formed to have an inclined angle with respect to each other, thereby supporting X axis, Y axis, and Z axis displacements.
Preferably, the overlapped portion (center portion) of the metal core extension is disposed to be offset from a center portion of a guide of the metal core toward an end of the metal core.
Preferably, the overlapped portion (center portion) of the metal core extension is coincided with an end of the steel cord, or located inside the steel cord.
Preferably, a lower surface of the metal core extension is coincided with the bottom surface of the metal core, or spaced apart from the bottom surface of the metal core.
Preferably, opposite surfaces of the metal core extensions form an angle of 45 degrees.
Preferably, at least two pairs of the surfaces of the overlapped portions (center portions) of the metal core extensions have the same inclined direction.
Preferably, an external bending surface of the metal core extension is formed to be wider, thereby dispersing stress locally applied when the metal core is bent and minimizing separation of the metal core and the crawler.
According to the rubber crawler having the metal core for improvement of wheel separation and durability, as described above, since the metal core extensions are formed at predetermined intervals along the lengthwise direction of the metal core of the rubber crawler, the present invention has some advantages as follows:
Firstly, since the Z axis which has the largest displacement as well as the X and Y axes are supported, it is possible to improve the wheel separation and minimize the Z axis displacement upon the interference of the foreign substances, thereby minimizing the lug breakage of the crawler due to the foreign substances.
Secondly, since the surfaces of the overlapped portions (center portions) of the metal core extensions are formed at the upper surface of the insertion portion of the steel cord, it is possible to minimize the metal core exposure and the breakage of the tread portion due to the foreign substances and bend fatigue.
Thirdly, since the thick rubber layer can be formed between the metal core extension and the steel cord so as to absorb shock when the metal core is bent, it is possible to minimize the breakage of the steel cord and the tread portion.
Fourthly, since the external bending surface of the metal core extension is formed to be wider, it is possible to disperse the stress locally applied when the metal core is bent, thereby minimizing the separation of the metal core and the crawler.
Fifthly, since the lower surface of the metal core extension and the bottom surface of the metal core form a predetermined angle in the lengthwise direction of the crawler so as to minimize the stress generated when the metal core is bent, it is possible to minimize the breakage of the steel cord and the tread portion.
Hereinafter, the embodiments of the present invention will be described in detail with reference to accompanying drawings. Hereinafter, the terms and words used in the description as described below are not limited to the typical or dictionary definition, and they can be interpreted as proper meanings and definitions consistent with the technical ideas.
Referring to
The lug 110 is formed to protrude on an external side surface of the crawler 100 and grounded on the ground, and the steel cord 120 is disposed in the crawler 100 so as to endure compressive load and the driving load of a tracked vehicle and maintain a sufficient rigidity and tensile strength even when using for long terms.
Further, the metal core 130 is embedded within the steel cord 120 so as to maintain the shape of the crawler 100 and transfer the driving force of an engine.
In the present invention, the metal core extensions 142, 144, 146 and 148 are embedded along both lengths on the basis of the center portion of the metal core so as to be alternate with each other, thereby preventing wheel separation of the metal core 130.
Referring to
As shown in
Therefore, the metal core 130 supports the Z axis which has the largest displacement as well as X and Y axes, thereby improving the wheel separation. Further, when the foreign substances are interfered between the crawler 100 and the machinery, the metal core 130 reduces the Z axis displacement, thereby minimizing the breakage of the lug 110 of the crawler.
As indicated in “B” and “B′” of
Further, as indicated in “D” of
As indicated in “G” of
While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
Number | Date | Country | Kind |
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10-2010-0006985 | Jan 2010 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/KR2010/008883 | 12/13/2010 | WO | 00 | 7/23/2012 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2011/093590 | 8/4/2011 | WO | A |
Number | Name | Date | Kind |
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5522654 | Katoh | Jun 1996 | A |
7413268 | Kato et al. | Aug 2008 | B2 |
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202006013452 | Mar 2008 | DE |
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2039597 | Mar 2009 | EP |
06-087473 | Mar 1994 | JP |
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08-198154 | Aug 1996 | JP |
1997-226639 | Sep 1997 | JP |
2005-212741 | Aug 2005 | JP |
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Entry |
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International Search Report mailed Jul. 28, 2011 for International application No. PCT/KR2010/008883. |
European Search Report for EP 10844814.3, mailed Aug. 7, 2013, 7 pages. |
Number | Date | Country | |
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20120286566 A1 | Nov 2012 | US |