Regardless of whether they are fitted in double clutch transmissions, hybrid transmissions, rear wheel steering systems, thermal management modules or seat adjustment systems: EC motors are used in an increasing number of areas in modern vehicles.

“EC motors are true all-rounders and an indispensable part of modern vehicles”, says Dr. Jochen Schröder, head of the E-Mobility business division at Schaeffler in Bühl. Compared to motors with mechanical sliding contacts, brushless EC motors have a considerably longer life, higher efficiency, and they operate significantly more reliably. By the way, the abbreviation EC stands for “electronically commutated”, i.e. electronic switching of the voltage from one motor winding to the next.

Schaeffler is now developing and producing EC motors in Bühl and is thus
entering a growing business field. Of course, Schaeffler also uses the electric helpers itself, initially in a hydrostatic clutch actuator. In this application, the pressure required to actuate the clutch is built up using an EC motor.

Significantly increased power density

A special feature of the EC motors produced in Bühl is the single-tooth design of the stator installed in the motors. These are now individually stamped, stacked, insulated by means of injection molding, and joined to form a chain after being wound with enameled copper wire. This design provides a significantly higher power density compared to the so-called full-section design in which the laminated core of the stator comprises a closed ring. “We utilize our in-house production facilities for manufacturing EC motors – from the punching of the stator teeth through to the finished product”, says Schröder. This high level of vertical integration has numerous advantages: As Schaeffler now implements the entire process chain from the individual part through to the finished motor in Bühl, the experts in Production can respond more flexibly to customers’ adaptation requirements and are able to continuously optimize the production themselves.

"We utilize our in-house production facilities for manufacturing EC motors – from the punching of the stator teeth through to the finished product”

Dr. Jochen Schröder, head of the E-Mobility business division at Schaeffler in Bühl

Modular production system for different applications

The production process comprises a total of 25 steps, which are carried out fully automatically on a fully interlinked production line using two integrated injection molding machines, winding machines, and an end-of-line inspection machine. A driverless transport system supplies the production line with individual parts and transports the finished products. “Our team in Bühl is placing a special focus on flexibility for the development and production of future EC motors.”, says Benjamin Hoffarth, Head of Operations in the Actuator Systems business unit at Schaeffler in Bühl.

In this way, a specially developed modular production system of stators with three diameter classes (53 millimeters, 75 millimeters, and 86 millimeters) will cover various motor sizes and applications. The goal is also to adapt the future portfolio of EC motors in such a way that it can be used as widely as possible in the areas Actuator Systems, E-Mobility, and Industrial. This will enable Schaeffler to open up an ever increasing market.