Chain (technology)
Technical chains are used to transfer forces and movements. They are used in the following technical contexts, among others:
- Chain transmission for power and motion transmission
- Lifting equipment and lifting accessories
- Track drives in vehicles
- Chainsaws
- as well as many other applications ( anchor chain , timing chain, etc.)
Types of technical chains
Chains are available in 2 designs:
- Chains for lifting or fixing, e.g. B. an anchor chain , usually consist of round or oval rings, and are flexible in two dimensions .
- Chains for power transmission in machines, e.g. A bicycle chain , have articulated chain links that fit onto a toothed sprocket and are flexible in one dimension ; H. only movable in one plane.
Two-dimensional moving chains ( DIN 695 )
Ring chain
Ring chains consist of circular links, but do not have to be closed to form a ring. Rather for decorative and jewelry chains, as they are less resilient and bulky than chains with oval links.
Link chain / round steel chain
The link chain is the simplest type of chain in which the mostly oval chain links are fitted directly into one another. A link chain in which each chain link is twisted by 90 degrees so that the chain can lie flat is called a curb chain .
The ends of the rings are connected to one another using a suitable process ( DIN 765 , DIN 766 , DIN 685 , etc.), usually by butt or flash butt welding. This process ensures a weld seam strength that corresponds to that of the base material or even exceeds it. Round steel chains are also made of stainless steel.
The round steel chain is made from round steel. They are used, for example, as slings , e.g. B. as a 4-strand chain sling for lifting containers with a crane , in hoists , z. B. a chain hoist or in machines such as a chain bucket elevator .
If, as with a chain hoist, a force is transmitted from an electric motor to the chain, which then lifts a load, then toothed chain wheels or pocket wheels are used.
Bridge chain
The links of a bar chain have a stable cross bar in the middle of their eye, which on the one hand supports the link sides against being pulled together when loaded, and on the other hand prevents the links from slipping together in an unloaded state or foreign bodies from getting caught in the eye. Because the neighboring links are always well positioned in relation to one another, the bar chain runs well into the chain wheels , which is why it is often used as an anchor chain on ships.
Patent chain
So-called patent chains are made up of punched metal sheets that are folded into links and continuously plugged into one another for assembly. The links are often made of approx. 0.5 ... 0.8 mm thick brass or aluminum sheet. They are used, for example, to attach bath tub and wash basin plugs. In the past, the pull chains of toilet cisterns also consisted of such chains. Chains made according to the same principle are also made of polyamide .
Ball chain
So-called ball chains consist of tinny hollow balls that are connected to one another by a wire bridge. They only transfer low forces and are used to secure attached parts, such as plugs or keys, against loss.
One-dimensional moveable chains (articulated chains)
Above all, steel link chains are used as drive chains for the transmission of torques (see chain drive ), and occasionally they are also used as conveyor chains. An extension of the chain drive is z. As the spread of bikes derailleur .
Articulated chains are differentiated according to the type of connection between the chain links.
Pin chain
In this simplest version of a link chain , the plates rotate on bolts that are riveted or splinted . A subspecies of this chain genus is also called Gall chain after the inventor André Galle (1761–1841) . The leaf chain is another subspecies . It consists only of tabs and bolts. This is mainly used as a load chain for cranes and hoists. The leaf chain usually has a higher tensile strength than a roller chain and is guided over imperforate rollers (hence the name) instead of sprockets and therefore no torque can be transmitted from the wheel to the chain. The leaf chain is suitable for hanging, swinging or motion-transmitting applications. Leaf chains are often used as pulling or counterweight chains for machine tools, elevator doors, forklifts, spinning machines and similar lifting or loading devices.
Bushing chain
In the case of the bush chain (sleeve chain), the inner plate sits on a bush or sleeve that is located on the bolt. The additional joint reduces friction and wear .
Block chain
Roller chain
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The roller chain ( ISO 606, DIN 8187, DIN 8188) has achieved the greatest importance and popularity in technology, especially in the form of the bicycle chain , but also in other chain drives . The inner tabs sit on a bushing, referred to here as a sleeve, on the bolt. The outer tabs sit directly on the bolt. Between the inner tabs there is a roller on the sleeve. The roller reduces friction losses and wear. In addition to being used as drive chains in bicycles and motorcycles , roller chains are mainly used as timing chains to drive the camshafts of internal combustion engines . Because of the high load, the chains there often have double links that run on two adjacent chain wheels ( duplex chain ).
There are various special types of roller chain, e.g. B. the rotary chain . In addition to the standardized series, many factory standards are finding their way into the market to ensure that consumers are bound by one manufacturer. A typical example here is the pitch p = 38.4 mm used in the agricultural machinery sector, which deviates by 0.3 mm from the standard and makes it completely impossible to use standard parts from other manufacturers as spare parts.
Motorcycle chains and their dimensions
| Chain designation | standard | Chain division | Inner chain width (sprocket width) |
Roll diameter |
|---|---|---|---|---|
| T × W × D | 219 | mm / inch | mm / inch | mm |
| 1/2 × 3/16 × 7.75 | 415 | 12.7mm = 1/2 " | 4.7625mm = 3/16 " | 7.75 mm |
| 1/2 × 1/4 × 7.75 | 420 | 12.7mm = 1/2 " | 6.35mm = 1/4 " | 7.75 mm |
| 1/2 x 5.40 x 8.51 | Samson | 12.7mm = 1/2 " | 5.20 mm | 8.51 mm |
| 1/2 × 5/16 × 8.51 | 428 | 12.7mm = 1/2 " | 7.9375mm = 5/16 " | 8.51 mm |
| 5/8 × 1/4 × 10.16 | 520 | 15.875mm = 5/8 " | 6.35mm = 1/4 " | 10.16 mm |
| 5/8 × 5/16 × 10.16 | 525 | 15.875mm = 5/8 " | 7.9375mm = 5/16 " | 10.16 mm |
| 5/8 × 3/8 × 10.16 | 530 | 15.875mm = 5/8 " | 9.525mm = 3/8 " | 10.16 mm |
| 5/8 × 3/8 × 11.10 | 532 | 15.875mm = 5/8 " | 9.525mm = 3/8 " | 11.1 mm |
| 3/4 × 3/8 × 11.96 | 630 | 19.05mm = 3/4 " | 9.525mm = 3/8 " | 11.96 mm |
| 3/4 × 3/8 × 12.7 | 632 | 19.05mm = 3/4 " | 9.525mm = 3/8 " | 12.7 mm |
A special feature of motorcycle chains is the guarantee of lubrication by means of rubber rings or lamellae. These chains are known as O-ring and X-ring chains . The lubrication interval is extended for such chains, but care must be taken when cleaning that compatible agents are used. Boiling the chain in oil or petroleum, for example, is prohibited.
Thinner chains can lead to more efficient power transmission, but may not be able to cope with the load (permanently). In road traffic you should therefore use the chain width recommended for the respective model, as a chain break is a serious danger.
Bearing collar chain
The bearing collar chain is a special form of roller chain commonly used in bicycle technology, in which the bushings are replaced by projections on the inner plates. The thus achieved lateral flexibility is in derailleurs of advantage.
Lamellar chain
The slat chain has particularly small wire-like links and thus achieves particular flexibility. Movable lamellae arranged across the chain length serve in the continuously variable transmission to grip the changing tooth spacing of the conical pulleys (see chain transmission , CVT and PIV ). It is a traction device for belt drives.
Tooth chain
The inverted tooth chain is a form-fitting belt drive. It engages with its toothed plates in the teeth of the chain wheels. These take over the pulling force. An essential design feature is the two-part rocker joint. When the chain links are bent, the two pivot pins sway and roll off one another. The inverted tooth chain is known for its quiet running and is also known internationally as the Silent Chain.
Rotary chain
The rotary chain is a variant of the roller chain. Instead of different inner and outer plates, only one type of plate is used. These are cranked. The tab on the inside of one joint functions as the outer tab on the next joint. The cranked link plates give the chain great elasticity, which means that load shocks are well absorbed.
A single cranked link can be helpful in rare cases of bicycle construction, for example on tandems without an adjusting eccentric on the front bottom bracket, as the chain length can be extended by just a simple amount of the chain pitch and can therefore be adjusted more precisely.
Plastic chain
Plastic chains are increasingly used for certain applications, as link chains, for example, for clearing soil and floating sludge in sewage treatment plants or in the petrochemical industry. The advantages are a lower energy requirement, a longer service life and a significantly shorter amortization period than with conventional systems.
Special shapes
Push link chain
The push link chain - also push link chain - is for use in CVT transmissions, for example in the Fiat Panda Selecta or Subaru Justy. It can transfer the force to the flanks and behaves like a V-belt without the disadvantage of stretching and wear. There is also an application in lifting technology for this design as a lifting, pulling and pushing chain.
Flat top chain
Flat top chains are conveyor chains and consist of plates that are connected with hinges. They are used for the transport of piece goods that are not too heavy. They are often used in packaging technology, in wet or dry areas, e.g. B. when transporting bottles or boxes on the flanks of the horizontally guided chain.
Clip chain
Clip chains (also clip chains) are transport chains that are equipped with a large number of clip-like grippers along the chain. They are used in film stretching machines, packaging machines and textile machines to convey slack rolled goods (plastic film, fabrics) through the machine.
Apron conveyor chain
Apron chains consist of a basic roller chain with attached steel plates or plastic plates.
Multiflex chains
The Multiflex chains are plastic chains that are connected by a joint. The main advantage lies in the possibility of carrying out both curve and inclined conveying in one line.
Crawler chain / caterpillar chain
In tracked or caterpillar vehicles , the wheels run on a crawler belt , a circumferential row of plates connected like a chain. Due to the much larger ground contact area compared to wheels, the vehicle achieves better traction with less pressure and is easier to maneuver in otherwise impassable terrain. Some - rather small - tracked vehicles also use a circumferential belt as a "chain", mostly made of rubber with a high-tensile insert, a non-slip profile on the outer circumference and blocks on the inner circumference to guide the wheels. In contrast to steel link chains, these chains do not damage the ground and are more economical to manufacture (only one part) (see also chain pads ).
Processing equipment for ski slopes run on extra-wide chains made of rubber belts with upright aluminum profile webs in order to provide good support on transverse slopes, to compress a lot of snow and to crumble hardened surfaces. The simplest little ski-doos (ride-on snow caterpillars for 1–2 people) sometimes run on a single rubber caterpillar in the middle and are only controlled by a steering wheel pushed forward.
Saw chain
The structure of a saw chain is similar to the roller chain of a chain drive. Their links can be moved via a gear wheel located within the chain circle. In addition, a saw chain has outwardly directed knife-like prongs, the so-called chisels, with which the saw chain can plan off wood while rotating over a so-called sword and thus make the saw cut.
Ball or roller chain for linear guides
Ball chain
Visually appealing, smooth to the touch with the hand, easy to slide through holes and easy to clean on the surface are small ball chains. They can be found for the pull operation of high-mounted toilet cisterns, on floor lamp pull switches, as attachment of bathtub plugs, but also for holding sample plates (e.g. Formica) or cylinder keys from (estimated) 1950 onwards. The balls are 2 - 6 mm Diameter, are mostly made of brass and nickel-plated or chrome-plated. To produce the ball chain, short pieces of wire are compressed flat on both sides like a nail head. A short piece of pipe is then pressed over it in such a way that it forms an (approximated) ball with 2 small openings, each of which holds the compression head inside the ball, but allows the uncompressed wire some freedom of movement.
Such chains, about 2 mm thin, but made of stronger stainless steel, are also used to attach the "dog tag", the identification tag of soldiers, for example in Austria around the neck.
A cylindrical, boat-shaped sheet metal sleeve with a longitudinal slot on the side, which widens in the shape of a fish in the middle, allows both end balls of a chain to be clamped one after the other, which is then closed to form a key chain ring. Cylindrical spring sleeves that can be pushed over the shuttle are available so that the lock does not inadvertently come loose under certain kinking loads. Screw connectors are also less sensitive to kinking, but they can only be pressed onto chain ends industrially.
Ball chain hoists (at the end of the cord) are also well suited for setting ventilation or (self-closing) window blinds by hooking them into fork-shaped mounting brackets.
Similar fine ball chains made of polyester particles with regularly coaxially sprayed (cast) plastic balls serve - as a weighted loop to the ceiling - to control vertical blinds.
Semi-rigid ball chains made entirely of flexible silicone, with a handle and about 3 balls with a diameter possibly increasing in the range of 2 - 4 cm can be used for anal or vaginal sexual stimulation.
The pictorial metaphor - a black ball on a chain on a clamp on the leg - that symbolizes imprisonment is also called a ball chain.
Chain belt
A tight parallel winding of thin synthetic fiber ropes is fixed at regular intervals with C-shaped clips made of round wire. Such a band with a circumference of 50 cm was used in Pfaff sewing machines from 1965 on cast zinc wheels with grooves and collars to couple the upper and lower drive shafts.
See also
- Stainless steel chain
- Forest chain
- Pump chain
- Shuttering chain
- Sheet pile chain
- Sprocket
- Tank conveyor
- Chain shipping
literature
- Ketten Wulf Betriebs GmbH (ed.): Conveyor chains and chain wheels. Basics, further development and application examples, Springer Vieweg Verlag, Wiesbaden 2017, ISBN 978-3-658-08921-4 .
- Hans-Günther Rachner: steel link chains and chain drives. Springer Verlag, Berlin / Heidelberg 1962.
Individual evidence
- ↑ BGI 810-3, 2.1 Slings, safety during productions and events - loads over people
Web links
- Manual chain technology construction documents / calculation examples (accessed on July 10, 2020)
- DRIVE AND CONVEYING TECHNOLOGY (accessed on July 10, 2020)
- Quality class 10 lifting accessories (accessed on July 10, 2020)
- Debit tables (accessed July 10, 2020)
- Lifting technology for lifting loads (accessed on July 10, 2020)