For mixer drive systems, why are gears preferred over belt drives ?
Mixer Gears are used to transmit power from one rotating shaft to another under the following conditions which are commonly encountered in mixer drive systems:
(a) The distance between the axes of the connecting shaft is short.
(b) The speed of the shafts is low
(c) The speed or velocity ratio of the connecting shafts is to be maintained as constant.
(d) The torque to be transmitted is high.
(e) There is a need to step up or step down the speed, (e.g. – in a tangential sigma blade mixer, the ratio of the front blade speed to the rear blade speed is 3:2)
The motion of belts and shafts have insufficient grip. As a result, this may cause some forward motion of the driver without carrying the belt with it. This may also cause some forward motion of the belt without carrying the driven pulley with it. This occurrence is termed as “slip”. The effect of slip is that it reduces the velocity ratio of the system.
In precision machines such as mixers, where a definite velocity ratio is of importance the only positive drive is through gears. For example, in an overlapping double arm sigma mixer, both the front and the rear blades rotate at same speed. Since the area of rotation of the two blades overlaps, the two blades are positioned such that the phase difference between them is 90 degrees. A slip in the system can cause a change in this phase angle and can lead to the blades colliding with each other when in rotation. To avoid this, gears are preferred. A gear drive is also preferred when the distance between the driver and the follower is less.
Unique Mixers & Furnaces Pvt Ltd
Contact Person: Mr Jayesh R Tekchandaney
Phone – +91-22-25801214/25822385
Website – www.uniquemixer.com