Maintenance traction project.

This project is about auxiliary electric motor for slow/maintenance speed operation.

We have 5 Bucket Belt elevators and only 3 of them are controlled by a Frequency Converters, the most powerful ones (110kW each). The smaller ones are direct start speed only, so the motor spins ≈1500 rpm.

Maintenance speed is highly necessary to be able to see the Buckets and the belt itself while it rolling.

This way I found the motoreductor out of another deactivated machine, produced support and traction elements.

The parameter of speed of this motoreductor is 99 rpm

The calculus I've used to get a desired speed are really simple.

Let's see the basic properties of the machine it self (mean elevator).

Motor 1470 rpm (a)

Gearbox reduction ratio 1:26 (b)

Revolutions per minute = a/b

Driving head pulley revolutions ≈ 56,54 rpm (z)

Driving head pulley ø 1,12 m (r*2)

With this data we can find:

V=2πrz/t Is the formula to get a speed

V = 2*π*0,56*56,54 / 60

V = 3,315678775

Belt speed ≈ 3,32 m/s

The desired speed of belt is about 0.45 m/s, as it is comfortable to work with.

Motoreductor speed 99 rpm

Driving head pulley revolutions ≈ 3,81 rpm (z)

When the motoreductor is coupled to reduction gearbox gives the next speed of belt:

V=(2πrz/t)

V = 2*π*0,56*3,81 / 60

V = 0,223294739

Belt speed ≈ 0,22 m/s

To increase the speed I needed to install chain gear transmission with increasing ratio 1*1,78

After all installed the speed became around 0,4m/s

Belt speed = 0,22*1,78≈0,4 m/s 

With this all job done I tried to start the system...

When I connected the cable the motor came with a huge kick then stabilized with normal speed. It happened every single start I've made. Clearly it needed a smooth starter.

In fact this motoreductor has been working with a Frequency Converter so this came as perfect as it is.

And after basic setup everything became as it expected to be... PERFECT!

This is how could look a low budget project.