Die Cast Rotors

Why Die Cast Copper Rotor Motor? What it can do?

AC Squirrel Cage Induction Motors were originally invented with ‘Copper Bar’ rotors with ‘End Rings’ brazed to the Bars making it look like a cage and thus the name Squirrel Cage Induction Motors. This is how these Motors were made for almost 60 years world over from the year 1900. Then as a Technology improvement and enabling mass and defect free production the Die Cast Aluminum Rotors got developed totally eliminating bars insertion and end rings and brazing etc. This got readily adopted all over and today it dominates the entire world of LT Squirrel cage Induction Motors.

Copper is after all the best Conductor of Electricity and the question arose only towards the end of last century ‘Why not Copper Die Cast Rotors?’ The main hurdles were the high melting temperature, high heat conductivity and low die life and some more problems. The Technology is now perfected and available with few manufacturers at present including Kitra Industries (India) with proven ability and performance.

Apart from various impressive advantages, DCR also provide a very good flexibility and scope for the designers for achieving wide range of performances and efficiencies to suit different needs and specifications.

International experience is also recorded that there is good scope for material conservation and cost reduction by designing and employing DCR in the Induction Motors. Die casting is widely recognized as a low cost manufacturing process. However, the non-availability of a proven, cost-effective mould material had prevented the manufacture of copper cast rotors. After years of technological efforts for developing method of Die Cast Copper Rotors Kitra Industries (Surat, India) has succeed to develop its own technology to make Copper Die Cast rotors.

After years of practice and tests today we are able to provide copper die cast rotors to motor manufacturers. Today world motor manufacturers are analyzing and adopting the advantages of this new generation of rotors, today we are supplying EC grade Die Cast Copper Rotors to many company’s in India as well as out side India in a batch supply’s, we are also supplying sample rotors to any interested company according to there desired sizes / designs of end-ring against nominal Die Cost.

Our Work was highly appreciated by Copper Development Association (USA) and International Copper Promotion Council India (ICPCI).

What are the benefits to motor and pump manufactures for using DIE- CAST COPPER ROTORS?

The superior conductivity of copper over aluminum, ensures reduction of motor losses by 14 – 23% and rotor I2R losses by 29 – 41%, leading to improvement of the overall efficiency of the motor by at least 2%, for the same slot design.
Copper Die Cast Rotors operate at 10 – 12°C less, than Aluminum die cast rotors, resulting in doubling the life of the insulation, thus increasing the service life of the motor.
Proper selection of diameter and size of other components results in the overall cost of the motor by 7%.
Compared to aluminum die cast rotors Copper Die Cast Rotors can withstand higher momentary overloads due to copper’s inherent property of lower resistance.
As Copper receptivity is lower than aluminum, a Copper Die Cast Rotor helps the motor to develop approx. 80% higher torque compared to aluminum die cast rotors at same slip.
The smaller size of components used, results in sleek design of the motor.
Reduced losses increases the overall efficiency of the pump, compared to aluminum die cast rotors.
Compared to fabricated copper rotors, Copper Die Cast Rotors offer better dynamic balancing, ensuring smooth operation of the submersible pump.
Due to higher speed, the hydraulic efficiency of a pump is improved by 60%, in comparison to aluminum die cast rotor motors, resulting in increased output from the pump.
Lower temperature rise during operation increases the insulation life, resulting in a longer lasting pump.

The pictorial presentation attached giving various Electrical, Mechanical and Thermal advantages of Die-cast Copper Rotors help conceive the various dimensions of benefits extended by this latest advancement and Technology.

Kitra Industries is offering and supplying sample rotors on nominal cost, so more and more motor manufacturers can test the advantages of DCR which will enable them to make this new product line of high efficiency motors with DCR.