Double Pitch Chain Structure
1. Structural drawing
Basic 3 dimensions of chain
The basic three dimensions of a chain are pitch, roller diameter, and inner link inner width.
When these dimensions are the same, then the chains and sprockets are interchangeable.
Explanation of terminology
- *Slip fit
- When the pins and holes are fitted together, there is a continuous loose fit.
- This is a fit where the range of hole tolerance is larger than the range of shaft (pin or bush) tolerance.
- *Press fit
- When the shafts and holes are fitted together, there is a continuous interferential fit.
- This is a fit where the range of hole tolerance is smaller than the range of shaft (pin or bush) tolerance.
2. Structural Parts
|1. Plate||2. Pin|
|The plate bears the tension placed on the chain. Because the accuracy of the holes into which pins or bushes are press fitted affects chain quality, plates are manufactured with particular precision and finished into tough plates with high fatigue strength and impact resistance.||The two ends of the pin are press fitted to holes in the outer plates and riveted in place. For Hollow Pin Chain and Poly Steel Chain, they are press fitted only. Because the pins are subject to shearing and bending forces via the plates, and because the bushes rotate and slide along the pins as the chain articulates, they are manufactured with an emphasis on strength and wear resistance.|
|3. Bush||4. Roller|
|The two ends of the bushes are press fitted to the inner plate and function as bearings for the pins and rollers. They are subject to complex forces through the various parts, and are finished to specifications having high wear resistance.||Rollers are slip fit onto the bushes and reduce mechanical shock when the chain engages the sprocket. In addition, they serve to reduce running resistance by turning when the chain is in motion, making the chain run smoothly. Wear resistance is important.|
|5. Attachment||6. Spring Clip/Cotter Pin|
|Bolt holes are drilled for attachments.
||Spring clips and cotter pins prevent the connecting plates from detaching and are important components to maintain the intrinsic strength of the chain. Always install these parts.|
|7. Inner link||8. Outer link|
|The ends of the two bushes are press fitted to the inner link plate to form the inner link. Rollers are slip fit over the outside of the bushes.||The ends of the two pins are press fitted to the outer link plates. The ends of the pins other than those on connecting links are riveted in place to prevent detachment. For Hollow Pin Chain and Poly Steel Chain, they are press fitted only.|