The variable speed drive has two broad functions in industry:
1 – To provide a complete range of speeds to enable optimum operation of individual machines or equipment.
2 – To permit accurate control of production flow through related machinery and plant, so that plant efficiency may be optimised.
Operating speeds have a vital effect on cost and quality of production. Speeds that are too fast or too slow are inadequate, wasteful and cannot be tolerated in efficient manufacturing. Correct speeds must be used and they are dependent on variable conditions which are factors in every phase of industrial production.
Variable speed drives make it possible to secure the correct speed for almost every manufacturing operation. Only through infinitely variable speed control can the utilisation of many machines be realised.
The specific advantages of Reeves Varispeed Motodrives are readily understood when the following conditions are examined, some or all of which are factors in every phase of industrial production:
1 – Processing different sizes, shapes, quantities or grades of product on the same machine.
Reeves Motodrives enable single machines to produce more output than is possible at fixed speeds, by increasing the operating range, thus reducing unit costs.
2 – Changes in composition, molecular construction, density or character of material during processing.
Reeves Motodrives permit accurate manual or automatic control of speed to compensate for changes in consistency, density, viscosity, etc. during processing.
3 – Variance in temperature or atmospheric conditions.
Reeves Motodrives offer flexibility of operation in heating, baking, drying, cooking, cooling or chilling operations by enabling compensation for fluctuations and variations in temperature, humidity, moisture content and atmospheric conditions.
4 – Changes in production schedule.
Reeves Motodrives make conveyor speeds readily adjustable. They provide the desired speed without interrupting production flow. Delays, congestion, over or undersupply at critical points on production lines are reduced. They also provide flexibility to meet changes in operation caused by new designs or new sequences of processing.
5 – Changing peripheral speed during manufacturing operation.
Reeves Motodrives using automatic speed control can maintain uniform peripheral speed on increasing or decreasing diameters. This ensures uniform cutting speeds on rotary veneer lathes, uniform loading of cable strands on reels and even tension on wind up rolls.
6 – Synchronising machine speeds.
Reeves Motodrives allow continuous flow of material from one item of equipment to the next. This eliminates material waste and ensures high quality and uniformity of product.
7 – Variance in number of skill of machine operators.
Reeves Motodrives allow for differences in capability of men and machines by providing the flexibility needed to speed up or slow down to meet changes in number of operators or match differences in skill between operators.
Machine constructors and manufacturers in every line of industry now realise that the investment for adequate variable speed control equipment is repaid many times over in greater machine flexibility and utilisation, increased capacity and lower production costs.
1 – They are Australian-made, so spare parts are readily available and drives can be suited to suit specific applications.
2 – Full speed range operation can be achieved without derating, fitting blowers for motor cooling or oversizing the motor.
3 – Being a simple belt variator, they can be easily maintained and serviced by the plant fitter. This eliminates costly service engineer calls.
4 – Catalogue duty rating is 24 hours per day.
5 – Ambient temperatures up to 40 degrees C without derating unit.
6 – A wide range of options are available.
ComInTec has developed a new modular torque limiter – the DSM – as an answer to some of the problems presented by high speed applications in heavy industry.
Specifically aimed at usage in mills, extruders, conveyors, and in the mining and earthmoving machinery spheres, the DSM caters for high torque, high speed and large shaft diameters.
The DSM is manufactured completely in steel with specialised heat treatment, ensuring long service life and consistency in performance.
The calibration torque is externally adjustable and is achieved by turning the adjuster not to increase or decrease the spring pressure. The adjustment ring nut has outer circumference notches, while on the module body there is a reference mark.
For each rotation of the nut corresponding to one notch, a torque figure is obtained. This figure is a result of the nut rotation and the number of modules mounted.
It is important that all nuts of single modules are adjusted in the same way. Calibration tables are used to assist in this function.
Once the required calibration is obtained, the adjuster nut is locked in position radially by a set screw.
The DSM series is available on short lead times ex the ComInTec factory in Italy.
For permanent magnet and shunt wound DC motors with 180 volts – as seen in most industrial applications – changing the speed is best achieved by using something like a KBWM controller from KB Electronics.
KB’s exclusive Plug-in Horsepower Resistor® automatically presets the drive’s IR Comp and CL circuits for safe operation on various motors. Although factory calibrated, internal trimpots for Min, Max, IR, CL, Accel and Decel can be used to fine-tune the KBWM™ for specific applications. Connections to the control are via a barrier terminal block. By changing the orientation of the front cover, the wiring can be brought in either from the bottom or the top of the control.
Motor failure due to demagnetization is eliminated by the patented ultra-fast Direct-Fed™ current limit circuit. The controls contain AC line and armature* fusing, which provide protection against catastrophic failure. Auto-Inhibit®, a KB exclusive, allows the drive to be turned on and off rapidly using the AC line without damage to the control and/or motor. The internal CL LED is a diagnostic indicator that lights when the motor is overloaded. A conveniently located front panel lighted rocker switch controls AC line input power to the drive.
Australian manufacturing continued to grow in the month of August, according to the Performance of Manufacturing Index by the Australian Industry Group. Rising exports were at the heart of the result.
The result of 53.1 (50 being equilibrium) represents a 1.8 point increase from July. In a report overview, the defence and mining sectors were also individually highlighted as having had a positive influence on the overall figure.
Machinery and equipment was the standout performer for the month. Analysis has placed the softening Australian dollar as a player in helping with orders, with the outlook set to continue. This is also assisting the mining sector overall, which contrasts with the outlook for the metals and metal products sector, which is still suffering from a continued downturn.
Paper and printing also continues to fluctuate on a monthly basis, as seasonal factors play their part.
The full report can be accessed here…
