2013年7月17日星期三

Lifting chain contacts in the form of lifting chain wear and its dimensional accuracy requirements


Lifting chain contacts in the form of lifting chain wear and its dimensional accuracy requirements  Mainly from two aspects affect wear: ① stress distribution.
Plane of the plane contact pressure distribution, the interface less a partial sliding surface is usually a uniform damage. Sphere or cylinder face contact with the plane, the contact stress Gaussian distribution, the center most. When the amplitude is low, often showed partial slip. Center because no phase  In sports, from damage; And when the amplitude increased to completely slip state, the situation is the opposite, since the center of pressure of the largest and most serious injury.

② the ability to keep debris.

When two planes generated when moving emblem on the surface uniformly generated wear debris, but the center debris easily overflow, longer retention time in the interface, less chance of contact with the environment, gathering debris may make the interface pressure rise accelerated wear and tear, it may also reduce the amplitude or friction factor, Thereby reducing wear. Ball to face contact with the plane, wear debris is not easy to maintain, the impact on the wear smaller than the former.

Hoist equipment at the factory when the need to undergo a rigorous inspection, general please circumstances and subject to corrosion design, precision, hardness and other aspects

of the inspection, and for checking the dimensional accuracy of lifting chain mainly involves two aspects, one is the chain ring Size, and the other is the length of the

We face in these two aspects to be a simple understanding.
(1) chain ring sizes include pitch, the minimum inside width, maximum outside width, maximum diameter welding, arc radius, welding zone length. Among them, the pitch, the

minimum inside width, maximum outside width dimension is a key test.

When the chain at more than the standard position, the chain ring resting on top of the teeth, prone to jump chain, fight tooth and so on. Pitch is too small. Mouth chain will

occur in the transmission wear off teeth problems worse and generate additional shock loading.

When lifting chain outside width exceeds the standard position, the chain sprocket chain ring can not engage people ride in the nest while the teeth waist. Caused jump chain, playing teeth, increased wear and reduce the transmission efficiency. The load chain ring width is too small, so that inter-link rotation difficult.

(2) load chain length includes the length of lifting chain, lifting chain pairing lengths.

Lifting chain length must meet the standards in the machine, such as double-stranded ship Discovery pairing chain length difference is too large, it will cause the blade deflection, chain center distance decreases occurred jump chain, fight tooth accidents.

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