- Chain Design
Economic success is predictable. The optimal chain design is the key.
The greatest possible efficiency of a drive system is the basis for optimal profitability. For this reason, our engineering department strives to support our customers already during the early planning stages of their projects. Because the optimal chain design is decisive for the reliable operational safety of your systems.
We plan and implement drive solutions for an extremely comprehensive range of applications. From heavy-load conveying and lifting systems to industrial applications with special requirements regarding temperature or corrosion resistance through to lubricant-free production lines in the food industry.
Based on our highly developed modular product system, we design tailor-made chain systems that meet all demands of your individual area of application. For this purpose, we create precise requirement profiles that serve as the basis for an optimal chain design and take into account a large number of factors whose precise adjustment is decisive for the long-term performance of your chain.
In addition to basic technical data such as drive technology, load, speed, ambient influences such as humidity and temperature, as well as lubrication, we work with you to gather further process and operating parameters as well as general economic requirements and purposes of your application.
A chain not only has to meet the technical requirements with regard to breaking load and fatigue strength in order to reduce unnecessary costs caused by downtimes. It is also important to avoid unnecessary effort due to oversizing.
The optimal chain design is also decisive for your maximum economic success.
Design of Roller Chains
The service life of a chain should only be determined by its wear behaviour. Wear occurs in the chain joints on pins and bushings. Wear is primarily dependent on the chain pulling force, the deflection movements of the links when running around the sprockets, the joint surface as well as the lubrication and the number of chain revolutions.
Therefore, the chain must be dimensioned in such a way that overload or fatigue fracture is prevented, i.e. plates and pins resist the tensile forces to be transmitted, the rollers withstand the stresses caused by running into the sprocket, and wear in the chain joints and on the tooth flanks remains within permissible limits of the expected service life. Chain drives only achieve a satisfactory service life if the sprockets are aligned, good lubrication is provided, there is a possibility of re-tensioning to compensate for the elongation occurring during operation, and vibrations of the slack and tight side or torsional vibrations of the entire drive are prevented.
The slack in the slack side of new chains should be around 1% of the shaft distance.
Basis for the selection of a chain
To select a chain, at least the following values for power transmission must be known:
- Power to be transmitted P in kW
- Speed of the driving wheel n1 in min-1
- Transmission ratio i = n1/n2 = z2/z1
- Operating conditions of the drive (shock coefficient fy)
- Shaft distance a in mm
If possible, sprockets with at least 17 teeth should be selected. For drives from medium speed or in the range of the maximum load, we recommend using sprockets with 21 teeth with a hardened sprocket. The largest number of teeth must not exceed 150 in general.
The optimum shaft spacing is between 30 to 50 chain pitches and should allow a wrap angle of at least 120° on the small wheel. In the case of chain drives with an incline of more than 60° to the horizontal, the necessary chain tension must be ensured by installing tensioning wheels or automatically acting chain tensioners.
In many cases, you can choose between a single roller chain with a larger pitch and multiple roller chains with a smaller pitch. Chain drives with multiple roller chains allow smaller wheel diameters in case of limited space. They cause less noise and vibrations than chains with a large pitch, which run on wheels with a low number of teeth.
Use our service to safely design the optimal leaf chain!
Design of Leaf Chains
The selection of leaf chains takes into account the load to be transmitted and the operating conditions, i.e. the type of load, the chain speed, the frequency of movement of the chain, the dimension of shocks and the operating temperature. The permissible dynamic tensile force depends on the fatigue strength of the plates and pins. The breaking force of the chains is used as an indirect benchmark and the fatigue strength is taken into account by a sufficient break safety factor. The type and design of the chain determine the level of the safety factor to be selected.
For the design of the load chains, the tensile force F and the operating conditions for estimating additional dynamic loads must be known. The required minimum breaking force FB of the chain is determined from the tensile force F, the factor f1 for the operating conditions and the safety factor S.
For the safety factor S, the regulations of the authorities and the TÜV apply. If there are no regulations, the factor S can usually be selected between 7 and 12, depending on the type of chain and the design (plate combination).
Take advantage of our service for the safe design of the optimal roller chain!
Design of tool magazine chains
Tool magazine chains serve as tool storage for machining centres and represent interesting alternatives to index tables, cassettes or portals. A meandering course of the chain ensures a high storage capacity of tools with a relatively small installation space.
The tool magazine chain is constructed as a Gall chain, with the plates rotating on heat-treated and coated steel sleeves. The various tool holders are integrated into the steel sleeves, which provide a gentle fit for the tool's tapered shank. The axial pull-off force can be adjusted depending on the arrangement of the chain (with tools lying, hanging or standing) and the weight of the tool.
Tool magazine chains are manufactured in various pitches according to customer requirements. In addition to the chain, the various tool holders (SK, HSK, etc.), as well as the matching chain wheels, are designed according to individual requirement profiles in consultation with the customer.
The following information is relevant:
- Which type of steep taper is used?
- What type of pull stud is used?
- In which position should the chain be installed?
- What pitch (depending on the tool size) should the chain have?
- What is the weight of a tool (especially important in case of a hanging arrangement)?
- Which pitch circle diameter should the sprockets have?
- How should the chain be run?
- How is the chain positioned when changing tools?
- Which clamping device should be used?
- How big should the pull-off force be?
- In which position should the clamping lock or release be attached?