Gearbox ratio

For both designs the conveyor torque equals the pinion torque times the gearbox ratio whatever the differential. 

The difference in rotational speed between the bowl and the conveyor is commonly referred to as the conveyor differential speed, N. Conveyor differential speed is calculated from a knowledge of the rotational bowl speed, S, the gearbox pinion speed, Sp, and the gearbox ratio, Rob ... 

With modern technology, the speeds of the bowl and gearbox pinion can be continuously measured with tachometers or proximity probes, and their signals fed to a simple PLC to work out. and even control, the differential. The PLC would need the gearbox ratio programmed in to execute this duty. 

Conveyor torque, T, is a measure of the force exerted by the conveyor in moving the separated solids through the bowl, up the beach and out of the decanter. It equals the pinion torque, T, times the gearbox ratio ... 

Early decanters using eddy current brakes were not able to indicate conveyor torque continuously. A reading of brake speed, and another of brake current, had to be recorded and used when referring to a brake calibration chart, to obtain the brake torque. Conveyor torque could be obtained by multiplying this figure by the gearbox ratio. A typical eddy current brake calibration chart is shown in Figure 7.1. 

Bowl speed Pinion speed Gearbox ratio Bowl diameter... 

For the braking power, it is necessary to know the gearbox ratio, which will be taken as 98 (from the manufacturer). 

The ranges of gearbox ratios and torque ratings are those that are known to have been used, or which have been quoted by the manufacturer. The maximum and minimum ratios do not necessarily correspond to the maximum and minimum torque ratings, respectively. A specific ratio and torque within the range cannot arbitrarily be quoted. For precise figures the supplier must be approached directly. 

Figure 2.8 shows a reduetion gearbox being driven by a motor that develops a torque T tn(t). It has a gear reduetion ratio of and the moments of inertia on the motor and output shafts are and /q, and the respeetive damping eoeffieients Cm and Cq. Find the differential equation relating the motor torque CmfO and the output angular position 6a t). 

During the startup of the line, the extruder was quickly identified as not having enough torque from the motor to make the product. At this point the best option was to change the belt sheave ratio between the motor and gearbox such that addi-... 

At a maximum rate of 440 kg/h, the extruder was rate limited by motor torque and not by the quality of the extrudate. This extruder was fabricated with a gearbox and sheave ratio such that the maximum screw speed was 105 rpm. Since the process was operating at a screw speed of 45 rpm, the sheave ratio could be changed such that the maximum screw speed would be about 75 rpm. This might allow the process to operate at rates up to 700 kg/h. Changing the sheave ratio will increase the torque to the inlet side of the gearbox. Care must be taken to make sure that the additional torque does not harm the gearbox. 

The power train on the extruder was also limiting the rate of the process. The extruder was driven by a 190 kW motor with a maximum speed of 1750 rpm and a maximum current of 262 A. The motor was directly coupled to a gearbox with a ratio of 13.91, providing a maximum screw speed of 125 rpm. The maximum torque available to the screw from the drive system was 14,200 Nm. As will be shown later, this gearbox-motor combination did not provide a high enough torque to the screw for this process. 

In order to provide a higher torque to the screw, a belt sheave system was installed between the motor and the gearbox. This sheave system had a reduction ratio of 1.95, reducing the maximum screw speed from 125 to 65 rpm. Sheaving... 

The experimental setup is shown in Fig. 1. It consists of the following items (1) an AC drive with a nominal speed of 1760rpm (2) a gearbox with a reduction ratio 3.53 1 yielding a rotating speed of 500 rpm (3) a torquemeter with a measurement range between 0 and 22.6 Nm (accuracy of 0.1% at full scale) and (4) a transparent vessel with a hemispherical bottom. 

Due to the reduction ratio between gear (3) and one of the large coupling gears (2), the reduction ratio of the gearbox (4) can be kept small. Consequently,... 

DIT ratios can be in the range of 0.2 to 0.7, but commonly they are 0.3 to 0.5. At equal power, large impellers rotate more slowly and require large gearboxes compared with smaller impellers. 

For radial flow impellers, large D/T ratios in many cases offer a considerable reduction in PiS at any one operational scale. However, any saving thus made may be offset by the increa cost of the gearbox etc. required to produce the high torque, low speed required, particularly on the large scale. For particle suspension alone, they are clearly inferior. 

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