The resin casting process for the windings is crucial for ensuring the performance and durability of the motor. This is precisely why many automakers favor and choose bdtronic impregnation systems. This process solutions provider from Wexheim has deeply integrated its expertise in dispensing, plasma, impregnation, and thermal riveting technologies with Beckhoff's PC-based control technology to meticulously create customized systems with highly optimized cycle times.
The higher the resin filling density in the stator/rotor slots, the better the heat dissipation and mechanical stability of the motor windings, thus comprehensively improving the performance of the electric drive system. Therefore, to develop high-performance impregnation systems, system suppliers must possess deep expertise in material preparation, resin dispensing, and curing processes. Since the 1970s, bdtronic has been deeply involved in the research and development and production of dispensing and impregnation systems, and currently has eight service and sales branches worldwide. The company's more than 580 employees are dedicated to the research and development and production of equipment and systems used in the electronics industry, electric vehicle battery manufacturing, and autonomous driving sensor technology. These advanced process solutions are widely used in single-component and two-component dispensing, plasma pretreatment, thermal riveting, and electric drive impregnation. "Almost all of the world's leading OEMs trust and use bdtronic's impregnation technology to produce motors," said Markus Rieger, Director of Channel Sales and Marketing at bdtronic, with pride.
From impregnation to high-efficiency dripping
Beckhoff's XTS magnetic drive flexible conveyor system is used in production units for the thermal riveting of electronic housings.
During the impregnation process, the motor stator/rotor is immersed in a container filled with resin until all gaps are filled. Then, a complex process is required to remove excess resin from the motor laminations. "This method is not only costly, but also unsustainable from the perspectives of material consumption, environmental protection, and personal protective equipment for operators," explains Florian Schütz, Sales Manager for the DACH region at bdtronic.
In contrast, the drip process is a more efficient method among impregnation technologies: the system can precisely apply the impregnation material in a predetermined amount at pre-defined locations. The resin flows between the stator housing and the windings and cures according to specified process conditions. "We developed and optimized the drip process to make it a sustainable and cost-effective alternative to traditional impregnation processes," emphasized Andreas Olkus, General Manager of bdtronic.
What advantages does this bring to customer applications? bdtronic has its own technology center focused on developing processes suitable for mass production. The parameters determined at this center are then applied to mass production processes to ensure that manufactured systems meet production requirements.
With our strong professional and technical capabilities, we have successfully achieved the automation transformation of our production process, ensuring its stable and efficient operation under various complex and ever-changing production conditions, and demonstrating excellent repeatability.
— André Hellinger, Global Head of Research and Development
Complex and precise motion control
In the initial stage of the entire processing, the robot precisely picks up three stators/rotors and secures them to tool holders. These tool holders are then guided through a system approximately 13 meters long via a conveyor chain. The stators/rotors are first preheated to approximately 100 °C, and then fed into a drip station controlled by approximately 50 servos for dripping. They then proceed to a gelling and curing zone at temperatures up to 180 °C, followed by a final cooling zone. At the end of the system, another robot removes the stators/rotors, preparing them for the next process.
To ensure all grooves are completely filled and to prevent resin dripping and waste, the stator/rotor must rotate continuously as it passes through the system. The sheer number of dispensing pumps and rotating tool holders densely packed along the chain reveals the high complexity of the motion sequences programmed using Beckhoff TwinCAT 3 software. One challenging factor is the constantly changing expansion of the chain at different temperatures. The positioning accuracy of the dispensing needle and rotating stator/rotor must be as high as ±0.1 mm. Furthermore, the servo pumps in the impregnation station must be synchronized with the motion control. Even the rotation of the stator/rotor must be precisely controlled to ensure it closely follows the curve of the conveyor chain and maintains a constant rotational speed. “We have invested a significant amount of time and effort in optimizing the software and motion curves to achieve perfect synchronization between chain-related positioning control and component rotation,” emphasizes Karsten Bauer, Head of Software and Electrical Design.
To further reduce the wiring required for the impregnation system, bdtronic will continue to use EtherCAT terminal boxes for distributed design, a design similar to the current system architecture of the dispensing technology business unit.
Keywords: tracking and tracing
“Precise temperature and dispensing volume are key factors affecting the quality of dispensing and dripping processes,” emphasized Antonia Anetzberger, Product Manager for Dispensing Systems. bdtronic places great emphasis on comprehensive process chain traceability, committed to providing process stability and reliability. This allows users to monitor the current position of each stator/rotor within the system and its impregnation conditions at any time. Furthermore, each stator/rotor is precisely weighed before and after impregnation to accurately record the amount of resin absorbed, further ensuring that the product meets quality standards.
Customers can easily access this production data using various interfaces, or they can connect the database directly to their own quality management system.
This is precisely the huge advantage shown by the openness and flexibility of PC-based control technology.
— Head of Beckhoff Mark Haydenfeld Sales Office
Mirko Ammersbach
On-site experts (from left to right): Antonia Anetzberger (Product Manager, bdtronic Dispensing Systems), Jörg Rottkord (Beckford Automotive Industry Manager), Markus Rieger (Director, Channel Sales and Marketing), Karsten Bauer (Head of Software and Electrical Design), Andreas Olkus (General Manager, Technical Department, all from bdtronic), Mirko Ammersbach (Head of Sales Office, Beckford Mark Heidenfeld), Florian Schütz (Regional Sales Manager, DACH), and André Hellinger (Global Head of R&D, all from bdtronic).
The hardware and software are highly scalable.
Machine manufacturer bdtronic utilizes Beckhoff's full range of components extensively across its systems, carefully expanding control hardware to meet performance requirements. Components such as the CX2033 embedded controller, C6930 control cabinet industrial PC, and C6040 ultra-compact industrial PC are seamlessly integrated into dispensing, plasma, thermal riveting, and impregnation systems. To minimize system footprint, bdtronic uses a large number of EtherCAT terminal boxes and EtherCAT terminal modules. "Currently, system wiring still requires relatively large spaces and is time-consuming," said Andreas Olkus. Beckhoff fully supports flexible and efficient distributed layouts through its pluggable MX-System cabinetless solutions, AMP8000 distributed servo drive systems, AMI8100 integrated servo motors, and EP series EtherCAT terminal boxes.
Also noteworthy are the XPlanar planar magnetic levitation transport system for realizing cutting-edge equipment solutions, Beckhoff's machine vision solutions, and the ATRO modular robot. "We can easily integrate these components into our control ecosystem when needed and precisely equip them with the most suitable industrial PCs to meet our actual needs," said Karsten Bauer, emphasizing the advantages of PC-based control technology.
