Roll drive arrangement

Roll drive arrangement In most cases, a high torque is necessary on the rollers. The drive torque should be divided equally between the two rollers and both rolls should (in the case of briquetting, must) rotate with exactly the same speed. Also in the case of smooth rollers and compaction of a sheet, even minute... 

Figure 274. Schematic representation depicting three different roll drive arrangements. (Explanations, see text)...

Developments in web tension control systems are providing increased capability and function to eliminate problems (Fig. 3-34). They include ultrasonic roll diameter sensors, pneumatic pressure gauge tension monitors, capston-Mt. Hope tension systems, and so on. As an example, replacement of a web-tensioning system s conventional electromechanical drive with an ordinary ac motor enables processors to lower system cost and improve web consistency, as has been done for many years. A vector control system uses a belt and pulley arrangement to remotely couple an encoder to the shaft of the ac induction motor. This approach provides closed-loop feedback, without requiring that one modify the relatively inexpensive motor by installing a special feedback device on it. 

This is a design whose time has really come with the advent of high-performance closedloop servo drives and the use of computers as system controllers. Feed rolls should be considered if your parts have complex hole patterns with many dimensional variations. Traditionally, multiple dies and very large presses would be required. The more common arrangement for this type of system is shown in Fig. 19. The punch tools inside the die are selectable by moving blocks over the... 

Figure 4.20 shows typical arrangements of horizontal- and vertical-axis paddle flocculators. The axes should rotate in alternate directions along the tank, e.g. in Figure 4.20 the first and third paddles rotate clockwise, but the second rotates anticlockwise. This rolls the liquid containing the floes from paddle to paddle without excessive shear as the paddle blades pass each other. If taper flocculation is desired, each sequential axis will rotate more slowly. The choice between horizontal and vertical axes depends primarily on mechanical considerations, such as the power drive system and the maintenance of bearings and support frames. 

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