Servo Motors Increase Flexibility of Coperion K-Tron Feeders

Technological advances in the industry, customer feedback, and various other factors have moved us to re-evaluate the situation and as a result, we have decided to change our standard offering for most feeders to servo motors as of August 2023.

Advantages of servo motors 

• Extended turndowns possible – up to 2000:1 RPM depending on configuration and bulk material characteristics
• Fewer gearbox variations needed for full turndown range
• Brushless, no wear parts
• Very high torque – quick to start even at very low speeds
• Significantly longer expected lifetime
• Also available for applications in hazardous locations
• Generally smaller & lighter, increasing weighing range
• Pluggable (quick-connect) connec­tions directly on the motor
• Higher energy efficiency
• Built-in speed pick-up encoder

Coperion K-Tron already has many years of experience with servo technology. The same trusted servo technology has been successfully implemented in the K3 Pharma feeder line since 2019. In addition, an increasing number of recent projects in a variety of applications have been built with servo motors at customer request. 

Similar to a DC motor, servos employ permanent magnets to create a magnetic field, however, there is no commutator with built-in brushes. The advantage of this style of motor is that when paired with an appropriate drive it eliminates the shortcomings of both DC and alternating current (AC) motors. Since the servo has no brushes – and therefore does not generate internal arcs/sparks – hazardous location options do not pose a barrier.

Due to the control that can be achieved given the synchronous nature of their operation, servo motors are capable of tremendous turndown (up to 2000:1 RPM) without overheating or loss of torque. As a result, it will no longer be necessary to offer multiple gearboxes to cover the full feed range of a feeder, making the implementation of a single feeder configuration more flexible in its application. In addition, thanks to the high resolution of our SFT weighing technology we can supply excellent feeding accuracy across the full feed rate range.

In loss-in-weight feeding applications, servo motors offer an additional advantage due to their smaller size and lighter weight. Servo motors are generally significantly lighter than their DC or AC counterparts. This reduction in feeder weight results in an increase of the scale weighing range.

Servo motors also have a built-in speed encoder. This means that closed-loop control is possible without the need for an additional speed encoder in the gear coupling. Closed-loop control continually provides the KCM with detailed information about the rotor position, which has a positive effect on feeding accuracy.

Servo motors therefore present the best-case scenario for operating feeders and their high turndown capability can minimize the need for feeder configuration changes such as screws, outlet tubes, and gear ratios over a wide range of feed rates and bulk materials.

As of August 2023, all new Coperion K-Tron feeders will be quoted with servo motors. AC and DC motors will still be available on request during a phase-out period. We will also be offering modernization packages for customers with Coperion K-Tron gravimetric or volumetric feeders equipped with DC or AC motors who would like to make the switch to servo motors. In many cases, line performance and process efficiency can benefit from upgrading to servo technology, with the features and advantages it brings.