Classification of Electric Drives With Factor

CLASSIFICATION OF ELECTRIC DRIVES WITH FACTOR

The choice of the electric drives

There are three classification namely

o     grope drive

o     individual drive

o     multimotor drive

1.          Group drive

One motor is used as a drive for two or more than machines. The motor is connected to a long shaft. All the other machines are connected to this shaft through belt and pulleys.

Advantages:

§  Grope drive is most economical because, the rating of the motor used may be comparatively less than the aggregate of the individual motors required to drive each equipment, because all of they may not be working simultaneously.

§  Grope drive reduces the initial cost of installing a particular industry.

§  Cost is less because of investment in one motor which is lesser in HP rating.

Disadvantages:

The use of this kind of drive is restricted due to the following reasons:

Ø        It is not possible to install any machine as per our wish. so, flexibility of lay out is lost.

Ø        The possibility of installation of additional machines in an existing industry is limited.

Ø        In case of any fault to the main driving motor, all the other motors will be stopped immediately.

Ø        so, all systems will remain idle and is not advisable for any industry.

Ø        Level of noise produced at the site is high.

Ø        Because of the restrictions in placing other motors, this kind of drive will result in untidy appearance, and it is also less safe to operate.

Ø        Since all the motors has to be connected through belts and pulleys, large amount of energy is wasted in transmitting mechanisms. Therefore, power loss is high.

2.             Individual drive

In this drive, there will be a separate driving motor for each process equipment.

One motor is used for transmitting motion to various parts or mechanisms belonging to signal equipment.

Ex: Lathe

One motor used in lathe which rotates the spindle, moves feed with the help of gears and imparts motion to the lubricating and cooling pumps).

Advantages:

§  Machines can be located at convenient places.

§  Continuity in the production of the processing industry is ensured to a high level of reliability.

§  If there is a fault in one motor, the effect on the production or output of the industry will not be appreciable.

Disadvantages:

Ø           Initial cost is very high.

3.             Multimotor drive

In this type of drive, separate motors are provided for actuating different parts of the driven mechanism.

Ex: cranes, drives used in paper mills, rolling mills etc.,

In cranes, separate motors are used for hoisting, long travel motion and cross travel motion.