Pulley

A technical component is called a rope pulley . It has the function of a permanently installed pulley over which a rope runs. In underground mining , this is a grooved wheel over which the the rope carrier coming hauling cable runs to the conveyor baskets. In day shafts, rope sheaves are installed in the headframe and in blind shafts in the blind shaft tower. Sheaves are not only in mining but also in hydraulic elevators, lifts and cable carsused. Sheaves must be checked regularly for damage so that the entire rope drive is in perfect condition.

construction

Sheave in Zabrze, Poland

A pulley is essentially a spoked wheel. The diameter of the sheaves depends mainly on the diameter of the respective hoisting rope. The diameter of the sheave must be at least 40 times the rope diameter. Depending on the type of rope used, the nominal rope pulley diameter must be up to 120 times the nominal rope diameter. The nominal pulley diameter is the arithmetically determined diameter of the pulley based on the groove base. Smaller sheaves have a diameter of 2.5 to 3 meters. Large sheaves have a diameter of 6 meters. Depending on its size, a rope sheave weighs from 1.2 tons (with a diameter of 2.5 meters) to 7.5 tons (with a diameter of six meters). There are spoke discs and solid wall discs. In the case of spoke discs, the pulley consists of the rim, the hub and the spokes. The number of spokes is different for sheaves from different manufacturers, it is based on empirical values. Full wall panels are either cast or made of solid material turned . In the wheel rim there is an outwardly expanded groove. The wreath is provided with one or more grooves that serve to better guide the rope.

Either cast iron or cast steel is used as the material for rope sheaves. Smaller disks with a diameter of up to three meters are made from cast iron. On larger wheels, different materials are used for the rim, hub and spokes for weight reasons. The spokes are either welded or screwed to the tread and the hub . If different materials are used for the individual components of the sheave, the hub and the rim are made of cast iron and the spokes are made of wrought iron. Cast steel is used for the axles. In order to reduce the mass of solid wall discs, the material between the hub and the running ring is partially removed from these discs. Small pulleys up to three meters in diameter are made from one piece, while larger pulleys consist of two or more parts. The hub is then undivided and the rim is made from two or three parts. To protect the hoisting ropes, the rim groove can be lined with a lining made of a softer material. In the case of systems with conveyor speeds above 4 m / s, it is usually necessary to provide the sheaves with a sheave lining. The material used for the pulley lining is made of wooden blocks that are hammered into the groove or gutta-percha , which is lubricated into the grooves in a soft state and then hardens. If the load is low, hemp straps woven from ropes are also used. In mine workings that are at risk of fire or explosion, such as B. in coal mining, the pulley lining must be made of flame-retardant material.

Function and tasks of the pulley

Rope sheave of the Rheinpreußen colliery in Duisburg

In principle, a sheave works like a fixed pulley . The pulley serves as a guide device between the conveyor and the cable carrier. The primary purpose of the pulley is to divert the hoisting rope coming from the drive in another direction. If the hoisting rope is deflected by around 180 ° by a pulley, this pulley is called a deflection pulley. In the case of shaft hoisting systems, the pulley is used to divert it into the conveying strand . Another task for the rope sheave is to transfer the rope loads to the headframe, to increase the wrap angle around the rope carrier and to adapt the rope spacing to the strand spacing. The pulley must be aligned accordingly for this. If electrostatic charges occur during operation, suitable measures must be taken so that these charges can be discharged. When the hoisting rope runs over the sheave, there is a loss of energy due to the internal rope friction and the bearing friction.

Individual evidence

↑ ^a ^b ^c ^d Walter Bischoff , Heinz Bramann: The small mining dictionary . Ed .: Westfälische Berggewerkschaftskasse Bochum. 7th edition. Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .
^ ^A ^b ^c ^d Julius Ritter von Hauer: The conveyors of the mines. 3rd increased edition, published by Arthur Felix, Leipzig 1885.
↑ ^a ^b ^c ^d ^e Gustav Köhler: Textbook of mining science. 6th improved edition, published by Wilhelm Engelmann, Leipzig 1903
↑ ^a ^b ^c ^d ^e ^f Arthur Katkow, Karl-Heinz Wehking: Topology optimization of rope sheaves . in: Scientific Society for Technical Logistics. (Ed.): Logistics Journal. Proceedings, 2013, ISSN 2192-9084 , pp. 1-6
^ Felix Gross: Seilbahnlexikon. Technology, relics and pioneers from 150 years of cable car history, epubli GmbH, Berlin 2011, ISBN 978-3-8442-1062-0 .
↑ Pfeifer Seil- und Hebetechnik GmbH (ed.): Instructions for testing rope sheaves with Pfeifer groove gauge. Memmingen 2012.
^ Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961.
↑ ^a ^b ^c ^d Technical requirements for shaft and inclined conveyor systems (TAS). Verlag Hermann Bellmann, Dortmund 2005.
↑ ^a ^b Hans Bansen (Ed.): The mining machines. Third Volume, The Shaft Carriers. Published by Julius Springer, Berlin 1913.
↑ ^a ^b ^c ^d ^e ^f Hans Bansen (Hrsg.): The mining machines. Fourth volume, The shaft production. Published by Julius Springer, Berlin 1913.
^ Hugo Hoffmann, Carl Hoffmann: Textbook of mining machines. Power and working machines . 3. Edition. Springer, Berlin 1941, XVI. Shaft hoisting systems, p. 215-236 .
↑ ^a ^b Thomas Kuczera: Determination of the stress on large sheaves. Institute for Materials Handling and Logistics at the University of Stuttgart, dissertation, Stuttgart 2012.

Web links

Commons : Sheaves - Collection of images, videos and audio files

lifting zone pulleys (last accessed on December 15, 2014)

[Quelle1-1] Walter Bischoff , Heinz Bramann: The small mining dictionary . Ed .: Westfälische Berggewerkschaftskasse Bochum. 7th edition. Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .

[Quelle6-2] A ^b ^c ^d Julius Ritter von Hauer: The conveyors of the mines. 3rd increased edition, published by Arthur Felix, Leipzig 1885.

[Quelle7-3] Gustav Köhler: Textbook of mining science. 6th improved edition, published by Wilhelm Engelmann, Leipzig 1903

[Quelle11-4] ↑ ^a ^b ^c ^d ^e ^f Arthur Katkow, Karl-Heinz Wehking: Topology optimization of rope sheaves . in: Scientific Society for Technical Logistics. (Ed.): Logistics Journal. Proceedings, 2013, ISSN 2192-9084 , pp. 1-6

[Quelle9-5] Felix Gross: Seilbahnlexikon. Technology, relics and pioneers from 150 years of cable car history, epubli GmbH, Berlin 2011, ISBN 978-3-8442-1062-0 .

[Quelle2-6] Pfeifer Seil- und Hebetechnik GmbH (ed.): Instructions for testing rope sheaves with Pfeifer groove gauge. Memmingen 2012.

[Quelle8-7] Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961.

[Quelle3-8] Technical requirements for shaft and inclined conveyor systems (TAS). Verlag Hermann Bellmann, Dortmund 2005.

[Quelle5-9] Hans Bansen (Ed.): The mining machines. Third Volume, The Shaft Carriers. Published by Julius Springer, Berlin 1913.

[Quelle4-10] ↑ ^a ^b ^c ^d ^e ^f Hans Bansen (Hrsg.): The mining machines. Fourth volume, The shaft production. Published by Julius Springer, Berlin 1913.

[Quelle10-11] Hugo Hoffmann, Carl Hoffmann: Textbook of mining machines. Power and working machines . 3. Edition. Springer, Berlin 1941, XVI. Shaft hoisting systems, p. 215-236 .

[Quelle12-12] Thomas Kuczera: Determination of the stress on large sheaves. Institute for Materials Handling and Logistics at the University of Stuttgart, dissertation, Stuttgart 2012.