Rope carrier
A cable carrier is the part of the drive machine via which the power provided by the drive shaft is transferred to the hoisting cable . The rope is moved with the rope carrier. The cable carrier is therefore the central machine component of a shaft hoisting system for the hoisting rope. Rope carriers are used in hoisting machines , winches and conveyor hooks.
Types
The types or types of rope carrier used are traction sheave , drum and bobbin . Each rope carrier has different properties, as well as advantages and disadvantages.
Comparison of the rope carriers | |||
---|---|---|---|
Rope carrier | Traction sheave | drum | Bobbin |
advantages | small dimensions and mass of the cable carrier |
double-strand multi-rope conveyance | slim design |
Tower funding possible | Rope for testing degradable |
twist free | |
Multi-rope conveyance possible | no zip line | no rope slip | |
good torque balance | good rope lubrication | ||
high speeds -> cheap engines |
for each depth suitable |
||
small engines | for large payloads | ||
low investment costs | |||
disadvantage | no double- strand multi -level conveyance possible |
large dimensions of the cable carrier |
due to the height, only low depth capability |
Zipline hazard | large foundations necessary |
low conveying speed | |
no rope lubrication | large mass of the cable carrier | no constant drive torque possible |
|
increasing stress with increasing depth |
slow-speed motors required -> expensive |
only single rope conveyance possible |
|
limited depth ability | maximum two-rope funding possible |
||
Drive torque is usually not constant |
|||
poor utilization of the electric motor power |
Swell:
properties
The properties that characterize a cable carrier are the cable carrier diameter, the permissible and existing cable deflection and the permissible surface pressure.
Cable carrier diameter
The rope carrier diameter depends on the nominal rope diameter of the hauling rope. Due to the minimal bending radius of a haul rope, the rope carrier diameter is, depending on the rope type used, the rope speed, the intended use e.g. B. as a stage winch, emergency travel winch, reel or machine, 15 to 120 times the nominal rope diameter. A reduction in the cable carrier diameter leads to high bending stress on the hoisting cable. This results in a shortening of the rope's lifespan, even with small changes. The reduction in the diameter of the cable carrier can only be partially compensated for by special cable constructions. In the case of reels and drum winding machines , the cable carrier diameter is also dependent on the cable length.
Rope deflection
The vertical offset between the run-off of the rope on the rope carrier and the run-up of the rope on the sheave or deflection sheave is the reason for any rope deflection. The rope deflection has a negative effect on the hauling rope. This results in rope wear, lining wear on the rope sheaves and on the traction sheave and incorrect windings when the drum is being conveyed. Therefore, unless there is a special cable guide device, the rope deflection should not be greater than 1.5 °.
However, rope deflection has different effects on the individual rope supports. In the case of floor conveyor machines with traction sheaves, the optimal arrangement of the sheaves is on top of one another, since no rope deflection occurs. Even with tower hoists with traction sheaves, there is no rope deflection. The situation is different with drum cable carriers, here in tower hoisting machines the cable deflection between the drum and deflection sheave becomes too great due to the small distance between the deflection sheave and the drum. In floor conveyor machines with drums, the optimal arrangement of the sheaves is next to one another, as this results in less rope deflection than with sheaves arranged one above the other.
Surface pressure
The surface pressure must only be taken into account if the traction sheave is used as the cable carrier. It must be ensured that a constant surface pressure is achieved over the entire arc of contact.
Areas of application of the rope carrier
Which cable carrier is used mainly depends on the load to be moved and the depth to be overcome. Traction sheaves can be used for conveyor systems with payloads of up to 80 tons and for depths of up to 2000 meters. At depths of up to 1,600 meters, conveyor systems with traction sheaves as cable carriers are the most economical. Traction sheaves are less suitable for very short shafts with a depth of less than 250 meters. Here drums are the much cheaper option. However, simple drums are less suitable for great depths. Drums are particularly unsuitable for heavy loads from great depths. This is primarily due to the fact that the diameter of the hoisting ropes and therefore also the diameter of the drums would be so large that this would be technically very difficult to control. For very deep shafts, Blair drums ("Double Blair Winder") are an alternative. Reels are mainly suitable for use as rope carriers in shaft sinking winding machines.
Individual evidence
- ↑ Heinz Pfeifer, Gerald Kabisch, Hans Lautner: Fördertechnik . Construction and calculation, 6th edition, Springer Fachmedien, Wiesbaden 1995, ISBN 978-3-528-54061-6 , pp. 10-22.
- ↑ a b Technical requirements for shafts and inclined conveyor systems (TAS) Sheet 11/9 Definitions online (accessed on July 18, 2016).
- ↑ a b c d e W. Sindern, St. Borowski: Safety considerations on shaft hoisting systems for access to a future deep geological repository . Working report NAB 14-75, National Cooperative for the Storage of Radioactive Waste (Ed.), Wettingen 2014, pp. 35–39.
- ^ A b Fritz Schmidt: The basics of the conveying machine system . First part, second increased and improved edition, Springer-Verlag Berlin Heidelberg GmbH, Berlin Heidelberg 1923, pp. 5, 143, 151-167.
- ↑ a b c Horst Roschlau, Wolfram Heintze: Bergmaschinentechnik . VEB German publishing house for basic industry, Leipzig 1977, pp. 256–262.
- ^ A b Paul Burgwinkel: Specialist article shaft conveyor technology . RWTH.
- ↑ a b c d e f F. Pfeiffer, T. Fass, S. Weber: Schachtfördersysteme . In: Final report on project 3608R02612, analysis of operational experience and its importance for the plant concept and the operation of a repository for heat-generating radioactive waste . Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH (Ed.), Order number 835655, GRS - A - 3613, July 2011, pp. A6-4 - A6-15.
- ↑ a b Wolfram Vogel: Requirements for suspension elements in today's elevator technology. Technical article, University of Stuttgart.
- ↑ Technical requirements for shaft and inclined conveyor systems (TAS) Section 3.3.13. Rope carrier.
- ↑ Hans Bansen (ed.): The mining machines . Third Volume, The Shaft Carriers. Published by Julius Springer, Berlin 1913, pp. 8-10.