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Material Handling Systems
Published in Susmita Bandyopadhyay, Production and Operations Analysis, 2019
Belt conveyor can also be roller belt conveyor (having rollers below the conveyor belt for the movement of the loads), slider belt conveyor (for carrying loads over both horizontal and vertical planes), telescoping belt conveyor. Chain conveyor is also a type of powered conveyor that uses single or double chain in order to pull and move especially pallet type of loads. This type of conveyor also carries loads over both horizontal and vertical planes. Live roller conveyor is also a type of powered conveyor in which “force sensitive transmission is used to disengage rollers.” Live roller conveyor can be belt driven live roller conveyor, or line shaft driven live roller conveyor. Platform conveyor is another type of powered conveyor with platforms and with chain that runs continuously in infinite loop. Besides, there are slat conveyor (made of nonoverlapping slats), vertical reciprocating conveyor, sortation conveyor, cart-on-track conveyor, tow conveyor, trolley conveyor, screw conveyor, pneumatic conveyor, vibrating conveyor, bucket conveyor.
Belt Drives
Published in Neville W. Sachs, Practical Plant Failure Analysis, 2019
Belts were developed to provide a means for transmitting power from the prime mover – a water wheel and later a steam engine − to the point where it was actually needed. The first belts were used in water-powered mills and they were generally flat, made from leather, and ran on wooden pulleys that had a very slight crown to keep the belt in position. In those early days, regardless of the power source, a mill would have a “line shaft” driven by the prime mover. Then, off the main line shaft, there would be many flat belts, each supplying a smaller line shaft, a machine, or a part of the process. (One of the truly impressive sights of my early days in industry was watching the “head operator” using a special stick-like tool to put a 24″ wide, 30-foot long flat belt on a line shaft pulley rotating at 500 rpm. A huge motor drove the main line shaft, which in turn drove 15 other machines.)
Key Factors in Mechanical Power Transmission Failure
Published in Randy Riddell, Practical Root Cause Failure Analysis, 2022
The line-shaft driven coater machine is driven by two 400HP (298kW) direct current motors. The line shaft is connected to two size 5 Beloit differential gearboxes to separate dryer sections and two size 1 Beloit differential gearboxes connected to backing rolls, as shown in Figure 6.5. The backing roll size 1 differential gearboxes are rated at 75HP (56kW). Gearbox sizing for paper machine line shaft drives is typical for 200% startup torque for high inertia drive sections so the size 1 gearbox should be good for an intermittent torque of 150HP (112kW).
Cotton mule spinning after Richard Roberts
Published in The International Journal for the History of Engineering & Technology, 2022
One of the reasons why the mechanism of the mule became so complex is that the carriage and spindles were driven differently when spinning on the outward run and when winding on the inward run of the carriage. On the outward run precise control of the speed of the carriage was needed whereas the inward run could be performed much faster. In the original Roberts mule everything was driven from a single point, a fast and loose pulley system connected by a leather belt to a counter shaft driven from the line shaft of the mill. Roberts mule had a single band which was used to draw the carriage both out and in, although it was driven differently on each occasion. On the outward run it was driven at constant speed through a drum and on the inward run through the scrolls on top of the headstock to give a varying speed, accelerating and then decelerating as it approached the roller beam, the relevant drives being brought into action by gearing. Subsequently the drive was split so that the drive for taking-in the carriage was independent of the drive via the rim-shaft when spinning. This independent drive was also used for driving backing-off and the camshaft, where fitted. McGregor’s mule of 1872 (Figures 12 and 13) does not have this feature, which seems to have been introduced around 1880 and was incorporated in Platt Brothers 1886 headstock. Writing in 1893 Thomas Thornley considered this the most important improvement in self-acting mules for many years.60 Steadily increasing spindle speeds required the rim-shaft to be driven faster but this made problems in devising suitable gearing for taking-in. Providing a separate taking-in drive totally independent of the rim-shaft allowed the pulleys to be sized as appropriate, relieved strain on the rim shaft and gave better control. Most manufacturers used a rope drive, with tensioning mechanism, for this purpose which was continuously driven from the counter-shaft and brought into action by a clutch, as can be seen in the Elk Mill mule (Figure 16). In their fine spinning mules Dobson & Barlow used a leather belt with fast and loose pulleys as this was considered to give a smoother action than clutch mechanisms.