energy chains, drag chains
Energy chains or drag chains are constructional elements that can be used to safely guide both cables and pneumatic or hydraulic hoses. Without these guides cables are quickly destroyed under continuous load.
for german Version see: Wiki Energieketten
'Energy Chains' are one kind of cable routing. Another possibility of cable routing are cable protection conduits or certain pipes. Cable drag chains are used in industry where mobile electrical parts or large machine parts have to be supplied with energy (i.e. electricity, oil or gas), for example to CNC lathes or industrial robots. In the energy chain, all drag chain cables and cables are routed to the desired workstation. In addition, such energy management protects the lines from external influences, so extend their life.
- 1 Construction and execution of energy chains
- 2 Important facts about energy chains
- 3 Arrangement types
- 4 Energy chain cable
- 5 Further properties of energy chains
- 6 Mounting accessories for energy chains
- 7 Energy Chains Manufacturer
- 8 Fields of application/practical examples
- 9 Configurator
- 10 Cable carrier systems
- 11 Alternatives
- 12 What else is meant by energy chains?
- 13 The term energy supply chain
Construction and execution of energy chains
Energy chains are available on the market in many different designs. As a rule, cable drag chains have a rectangular shape, and the cables are routed inside. The individual chain links between the beginning and the tail can usually be opened individually, so that access to the cables and lines at each point is possible and cables can be supplemented with already installed plugs later and with little installation effort. Within the energy chain, webs separate the individual cables from each other. At the beginning and end of the cables are clamped with a strain relief.
Energy chains are made of different materials. Mainly energy chains are made of solid plastic because this is less expensive than metal, does not rust and is easy to assemble. For special applications there are also steel / stainless steel and plastic chains with aluminum bars (hybrid).
Important facts about energy chains
For energy chains / cable drag chains / cable guides, care must be taken to ensure that:
- Downtime can be reduced
- the life is increased
- Travels are adjusted accordingly
- a universal use is possible
- They are installed to save space
- high speeds are associated with better service life
The chain applications of an energy chain are: The ➀ unsupported, the ➁ sliding, the ➂ hanging and the ④ standing arrangement.
Self-supporting energy chains
If the upper run of an energy chain does not touch the lower run over the entire travel distance, this is referred to as a "self-supporting arrangement". (A run in mechanical engineering is a part or branch of a running traction organ. If the traction organ is a chain, an additional distinction is made between the lower run and the upper run. )
This application of energy chains is the most common of all installation types when high dynamic loads and a long service life are required.
For this arrangement, energy chains with pretension (RV = radius with pretension) must be selected. Energy chains of smaller sizes are only produced in a version with a medium pretension (R). You will find this marking in connection with the radius value (e.g. RV 250) moulded onto the chain link.
Due to the pretension V, the upper run receives a slight upward curve in the unloaded state, which lowers to the horizontal due to the load with energy carriers. This ensures optimum force flow in the chain links (see figure 'Pretension V of the self-supporting drag chain').
The carrier height (HMA) must always be selected in accordance with the double chain radius R. The chain links must be fitted with a chain with an HMA. The upper run is the moving part of the chains with the carrier connection (MP) at the end of the chain, the fixed chain connection (FP) is located at the end of the lower run.
The required installation height (HS) results from the calculated height (2 * R + HG) plus a required safety S for the pretensioning curve (see sketch).
When installed, the self-supporting part can make a slight upward or downward arc due to the pretensioning of the chain. This pretension is needed to counteract the weight of the payload.
A distinction is made between the optimum condition with a very low sag FLg (this range is optimum in terms of service life and rolling behaviour) and the FLb range with a maximum permissible sag. If the sag is greater than FLb, the arrangement is critical and should be avoided. This is because the force curve in the side links is not optimal and a failure may occur. The permissible unsupported length (FL) must be selected depending on the travel distance and payload according to the type-specific diagrams. The energy conductors (cables, hoses, etc.) must be provided with a strain relief in or immediately behind both chain connections. A duct system is used to ensure that the energy chain runs smoothly.
Sliding energy chains
If the upper run of an energy chain glides on the lower run, this is called a "gliding arrangement". This application of energy chains can be found wherever long travels are required. The disadvantage is that the resulting friction does not allow such high speeds and accelerations as in the self-supporting arrangement.
The bending radius for a gliding application should be as small as possible, whereby the minimum bending radius of the energy carriers to be installed (cables, hoses, etc.) should be taken into account and not be undershot.
|Types of sliding applications||Description of use|
|Gliding application with lower chain connection (R>150mm)||If chain radii larger than 150 mm are used, the driver connection should be lowered so that the upper run can deposit as early as possible and glide. This greatly reduces the following loads:
Tensions in the chain link, Tensions due to vibrations in the area of the sag
|Sliding application of closed energy chains||Closed energy chains can also be used in gliding applications without any problems. The optimum height of the driver connection is to be selected as with open chains. Rear rotating chain links (RüR) must be supported by a fixed shim plate / carrier connection plate.|
|Support for parallel placement of the chain connections at the driver and at the fixed point||The driver connection plate must be designed so that the chain connection is parallel to the movement axis. The driver connection can be "top", "bottom" or "front". When fixing the chain connection "bottom" or "front side" and the location of the driver connection plate "bottom", the following must be taken into account: the supported chain links must be fully supported. The first link after the chain connection during rotation/movement must not be able to press against the plate edge "below". When fixing the chain connection "top" and placing the driver connection plate "bottom", the following must be taken into account: The supported chain links must be fully supported. The first link after the chain connection during rotation/movement must not be able to press against the plate edges "top" and "bottom".|
|Support for inclined positioning of the carrier chain connection||If the driver connection plate is designed so that the chain connection is not fastened parallel to the lower run but forms a line with the next chain links, the chain links should be provided with a rear radius immediately behind the chain connection. 20 m chain length or longer (corresponds to approx. 40 m travel distance with central feed) will result in high to very high tensile forces due to the friction of the chain. The most heavily loaded component is the chain connection on the carrier (MP). The flexible chain connections at this end (MP) must be used for problem-free loads, as the attachment is carried out as an extension of the sideband and therefore no torque occurs between the attachment point and the sideband.|
Hanging energy chains
If the radius arc of an energy chain with vertical movement direction is hanging downwards, one speaks of a "hanging" arrangement. A "hanging" arrangement should be used wherever energy carriers, guided by a cable carrier, pass through a vertical direction of movement. In this arrangement, travels - or in this case installation heights - of more than 100 m are possible. Especially in the field of material flow technology - especially in high-bay warehouses with storage and retrieval machines - energy chains arranged in this way enable a long-lasting and controlled energy supply.
The advantage over a vertical "standing" arrangement is the lower load on the drag chain. In the "upright" arrangement, the guided energy carriers rest on the radius arch. The additional weight not only loads the chain links, but also the chain connections in particular, which must permanently transmit the entire load (drag chain + payload).
Vertical movement without lateral acceleration
With this type of application, no lateral guidance is necessary. However, even without lateral acceleration, the Energy Chain system can oscillate if the driver connection is moved with fast successive travel cycles in conjunction with high acceleration and speed. This pendulum movement loads both the swivel joints in the chain links and the chain connections. In addition to very high signs of wear, it can also lead to breakage of the chain parts. Then a lateral guidance should take place.
Vertical movement with lateral acceleration
If lateral acceleration acts on the system in addition to the vertical movement - e.g. in the case of storage and retrieval machines (RGB) - a lateral guide of the hanging energy chain must be provided in any case. When planning such an application - movement in the X and Z axes - the energy chain should always be arranged so that the direction of action is transverse to the energy chain (X direction). This is the best way to absorb the forces.
In principle, both hanging chain strands must be guided laterally. However, this guide does not always have to be continuous over the entire travel distance. When placing the fixed point (FP = immovable chain connection) in the middle of the travel path, a lateral guide is only required "downwards". The run of the carrier connection (MP = movable chain connection) must be guided over the entire travel path of the energy chain, possibly with interruptions.
A vertically suspended arrangement cannot be considered a payload in the sense of a weight load. If the energy carriers guided in the energy chain have been correctly positioned and strain-relieved, the chain connections are only loaded by the dead weight of the energy chain. In this case, the weight of the energy carriers depends exclusively on the strain relief.
Standing Energy Chains
If the radius arc of an energy chain with vertical movement direction is upwards, one speaks of a "standing" chain application. Wherever energy carriers, guided by a drag chain, pass through a vertical direction of movement, and a hanging chain arrangement is not feasible for space reasons, a "standing" chain application is used. In contrast to the vertically suspended arrangement, travels - or in this case installation heights - of a few metres are possible. Especially in the areas of machine tools and handling machines, energy chains arranged in this way enable a controlled vertical supply of energy carriers even in very confined spaces.
In contrast to a vertically suspended installation arrangement, the vertically positioned drag chain ensures that the guided energy carriers always lie in the radius arc. The additional weight not only loads the chain links, but also the chain connections in particular, which must permanently transmit the entire load (chain + payload).
Energy chain cable
The energy chain cable or drag chain cable is a cable specially designed for use in cable carriers, for example a motor cable or a data cable. The drag chain cable is used for very high mechanical loads and cable carrier requirements in a wide variety of environments. They are said to have a high degree of flexibility with continuous movement and strong protection against external influences. In general, cables for cable carriers are halogen-free and flame-retardant.
Further properties of energy chains
Depending on the application, Energy Chains can fulfil further special properties. They can be:
- closed, thus special protection against dirt
- low-noise, a great advantage in production environments that are already noisy anyway
- with low abrasion for clean rooms
- without links as a band
- 3D, for industrial robots with multiple degrees of freedom
Mounting accessories for energy chains
- strain relief system
- Storage tray system
Energy Chains Manufacturer
Igus Energy Chains
igus GmbH is a developer and manufacturer of plastic energy guiding chains as well as maintenance-free plain bearings, spherical plain bearings and linear systems made of high-performance plastics. Igus Energy Chains are available in many different forms, including standard energy chains, E-Chains specially designed for long travels, chains for circular movements and energy chains designed for quiet, low-vibration use. The igus portfolio also includes conveyor chains, guide trough systems for energy chains, igus chainflex® cables and E-Tubes. Here, adapted E-Chains® can also be designed with the aid of a configurator. In addition, igus offers the development of objects as 3D print with a 3D printer - 3D print: With the aid of energy chains, drylinLinear circular guides and drylin screw drives, physical 3D products are created.
Murrplastik Energy Chains
Murrplastik Systemtechnik GmbH is a solution provider for professional cable management. Murrplastik's plastic products are used in almost all branches of industry when it comes to guiding, protecting and marking cables. At Murrplastik, individual energy chains can be configured online for each system using the Chainbuilder.
TSUBAKI cable drag energy chains
TSUBAKI Kabelschlepp GmbH offers a wide range of cable carriers and electric cables for use in small applications such as printers to large applications such as oil platforms. TSUBAKI Kabelschlepp manufactures energy chains made of steel/stainless steel, solid plastic or plastic.
Online retailers such as Amazon, Ebay or Conrad offer energy chains of different manufacturers and sizes. Attention: These chains are not intended and available for industrial large-scale use.
Some manufacturers offer comprehensive energy chain systems.
Chains can also be configured with CAD systems. With the CAD models, properties can be quickly checked and individually adapted in the configurator.
Fields of application/practical examples
The place where cable drag chains are used is where machine parts are supplied with energy, data, liquids or gases.
- Industrial robots - robots in an industrial environment
- machine tools
- construction equipment
- materials handling
- drive technology
- crane technology
- placement machines
In addition to applications in components, entire branches of industry also use drag chains:
- General mechanical engineering
- vehicle manufacture
- steel plants
- printing technique
Energy chains can be configured online. Via a so-called OnlineEngineer/Chainbuilder, many functions are taken into account when selecting and configuring suitable products. According to Tsubaki, for example, it "provides all the necessary technical and calculatory information on the individual products in the areas of cable carriers, cables and hoses and other accessories". Murrplastik provides the Chainbuilder with which individual cable carrier chains can be put together and suitable solutions found.
Customers can have CAD models produced and downloaded by the manufacturers, some of which have already been planned and implemented. For this purpose, specific software programs are made available or are still being developed.
Cable carrier systems
Energy chains are often used in machines in complete systems. Manufacturers also offer ready-made systems that are assembled directly at the customer's site. An energy supply system can have various components, including energy chains, connections, rails, attachments, hoses, ready-made cables or hydraulic components. There are also extended components for additional functions, e.g. a guide channel system for noise insulation.
Current collectors or slip rings are alternatives to classic energy chains. However, these are used for electrical energy. Optical transmissions or transmissions via radio waves are also used today.
What else is meant by energy chains?
In the wellness area there are chains that are hung around the neck and are supposed to give the wearer energy, as an energy chain. Such energy chains have, for example, a rose quartz or rock crystal ball on a ribbon or chain. Some chains have a silicon energy carrier embedded in them. This energy carrier is 'programmed' by prior treatment with an 'impulse technology'. Such an energy chain can also be worn in a trouser pocket.
In some companies, chains are used in the offices to run cables around the desk.
The term energy supply chain
The correct expression for this constructional element is energy chain, or EFK for short, but energy chain is often used in practice. The addition "guide" of the cable drag chain is based on the function of the component to guide and protect cables and wires. Without the guide, the cables would move uncontrolled, be damaged and thus reduce the service life of the cable. Cable trailing and Igus in particular use the term cable carrier for their product. Google lists more results for Energy Chain than for Energy Chain.
The article in Wikipedia has the title "Energy Chain in Wikipedia".