6. Large Pitch Conveyor Chains
Here are two examples. Case 1 reflects design considerations for a large pitch conveyor chain; Case 2 is for a small pitch conveyor chain.
Case 1. Bending moment: M 1 =1/6 3s3 H 3 t 2
Case 2.
t 2 = t/2 s 2 = 2 s (in order to maintain the same tensile strength) M 2 = 1/6 3 s 2 3 H 2 3 (t 2 ) 2 = 1/6 3 2 s 3 H 3 (t/2) 2 Bending moment: M 2 =1/12 3s3 H 3 t 2
Therefore, the large pitch conveyor chain (Case 1) can withstand twice the moment (M) of small pitch conveyor chain (Case 2). (2) Large pitch conveyor chain is designed to operate in harsh conditions. However, certain environments may affect the side plates, which can lead to stress-corrosion cracking, for example. This is a rare occurrence even for heat-treated side plates of this series. (3) The chain is designed with relatively large clearances between components. Typically, even if foreign material gets between the chain parts, the rollers will continue rotating, and articulation of the links is not easily impaired. (4) In Table 6.2, different materials are listed for each chain part of frequently used series. This lets you create a chain specifically for your operating environment at an economical cost. In Table 6.2, the “O” mark designates available materials for the chain parts. Table 6.3 shows the relation of materials and the chain parts. (5) Attachments have high strength. Take the commonly used A attachment as an example. During operation, it is subjected to bending and twisting forces. Bending moment and twisting moment are calculated according to formulas shown below.
Bending moment (M) = 1/6 3 s 3 H 3 t 2 Twisting moment (T) = A 3 t3 N 3 t 2
The allowable values of M and T are quite high for large pitch conveyor chain compared with small pitch conveyor chains. Attachments have higher resistance tobreakage during operation, but verify the bending and twisting moments. Manufacturers can help you determine the appropriate chain size and attachment for an application.
195
Made with FlippingBook Digital Proposal Creator