Motor technologies

LSP is development partner no. 1 for application-specific optimized e-motors

Not all electric motors are created equal! Depending on the application, motors can require high dynamics, high torque density or high power density. This of course results in very different motor types. Based on this complex task, Dr. Thomas Leiber rethought the physics of braking for specific applications and created three new topologies (A-C) for permanently excited electric motors.

These new motor topologies showed that groundbreaking new approaches can still be found in engine technology. Currently, development focus is on the power density of smaller motors (>25kW/kg), and we are convinced that the impossible can still be made possible here! In fact, we are working tirelessly on a fourth motor topology (D).

Highly effective development based on automotive standards

Our range of services includes all of the tools for taking into account the requirements of automotive standards (ISO 26262) while ensuring that we achieve optimum results in the shortest possible time – even for most complex tasks:

  • Freedom-to-operate checks through extensive patent analyses
  • Electromagnetic design and FEM structural analysis
  • Dynamic system simulation (Matlab-Simulink) for engines as well as electromechanical and electrohydraulic systems, taking into consideration thermal boundary conditions
  • CAD design including tolerance analyses
  • Electronics design with optimized DC link
  • Base code for a range of micro-controllers (fixed point, floating point)
  • Model-based software (control, diagnostics) with automatic code generation (Matlab Embedded Coder)
  • Motor control with optimized, self-learning field-weakening control
  • Redundancy concepts for fail operation mode
  • Prototyping (A/B samples) and small series production (< 1000 units p.a.)
  • Modern test benches (low and high voltage)
  • Application-specific design taking into account cost targets for small and large series
Awarded for innovation

Our motor technologies have been installed in the drive systems of innovative vehicles that have won international excellence awards. You can learn more in our History of Innovations.

Motor topology A: Motor with Double Air Gap (DAG) for high dynamic applications under load

Double Air Gap at a glance

  • Significant increase in dynamic response behavior even with high torque loads
  • Minimized power consumption and thermal load in highly dynamic cyclical operation
  • Very durable/long product lifetime through minimized mechanical stress on moving parts and optimally balanced magnetic forces in the motor
  • DAG concept: applicable for all common motor types such as internal and external rotors as well as for linear drives

DAG key data

Parameter Value
Stator diameter 85 mm
Stator length 30 mm
Rotor moment of inertia 34·10⁶ kg·m²
Maximum torque 6 Nm
Maximum dynamic >1,75·105 rad/s²

Dynamics that inspire!

The Double Air Gap (DAG) technology sets new standards in dynamics and response. Both the external and internal rotor designs of the motor will impress with their outstanding dynamics for continuous operation at maximum energy efficiency as well as with their highly dynamic operation due to minimum inertial mass movement. They reduce current spikes and are thus ideally suited for applications with strict on-board power supply requirements as well as for highly dynamic cyclical applications, for example in electric motor winding machines.

DAG motors differ from classic brushless synchronous machines in that the magnetic flux is shut off by a standing back flux, which requires a further air gap (Double Air Gap). The DAG principle significantly reduces the inertial mass of the rotor while at the same time only putting minimal mechanical load on the rotor due to balanced magnetic forces. As such, it achieves exceptionally high dynamic performance over a simultaneously long product lifetime of the motor.

Functionality and design

Standard internal rotor

In the standard motor, the rotor serves as both a magnet and bearing carrier and as a return path for the magnetic flux generating the torque. This is why the rotor dimensions are rather thick

DAG internal rotor

The patented Double Air Gap motors from LSP have a very thin rotor . The rotor only serves to carry the magnets and linkage elements to a shaft. Typically a deep drawn part is used as base carrier of the magnets which are glued to the rotor and overmolded.



For questions about patented technologies and licensing inquiries please contact our partner IPGATE.

Motor topology B: External rotor motor for applications with high torque density and a good balance between peak power and continuous power

The CPM 90 motor was conceived with specifications for a completely new winding technology. This innovation made it possible for the first time to automatically wind the stators of an external rotor motor using a high level of copper filling. Building on an initial basic patent, Dr. Leiber founded the company CPM (Compact Power Motors) and financed further development until the company was successfully sold. The CPM 90 motor has proven itself in a wide range of applications, for example as an essential component of award-winning drive systems for e-bikes, or in the long-term mass production of an innovative drive system in the maritime sector.


For questions about technologies, please contact Dr. Leiber’s assistant directly

Motor topology C: Multiple rotor motor with maximum toque density

The RFTR (Radial Flux Twin Rotor) is based on the knowledge that a magnetic circuit, which closes via an excited inner stator and/or outer stator over several rotors, can achieve very high torque density. This operating principle was already included in various RFTR patent applications and first prototypes in 2010, and was then successfully industrialized by a British motor manufacturer.

RFTR at a glance

  • Record-breaking torque density (250 Nm with only 14 kg motor weight)
  • Innovative production technology with self-supporting stator
  • Innovative approaches to engine cooling (14kg contains cooling system)
  • Latest LSP findings show great potential for a continued increase in nominal power density – the RFTR journey is not over yet!


For questions about technologies, please contact Dr. Leiber’s assistant directly

Motor topology D (future): High-performance motors (HPM) for electric drives (land, water, air)

A revolutionary motor, the Type D, is currently being developed in the LSP ideas factory – the primary task being to significantly increase power density compared with the “state of the art”.

This targeted, very high power density is intended, among other things, to support a revolution in aviation, with electrically driven aircraft (e-VTOL) for moving both passengers and freight. Certain aviation concepts have already reached their physical limits with the technologies that are currently available.

But other applications such as electrically driven watercraft would benefit immensely from electric motors with significantly increased power density. On top of that, in many autonomous vehicles such motors would offer the appropriate power reserves needed to meet demanding safety requirements.

For questions about technologies please contact Johannes Roßmann or Dr. Leiber’s assistant directly

Contact person

Are you looking for a competent, experienced development partner for your motor technology? We will analyze your specifications and operating conditions and implement a motor or, if required, an entire drive solution optimized for your needs. Feel free to contact us regardless of whether you prefer a patent-free solution, you are looking to license our patented motor topologies, or you are interested in a transfer of know-how in the field of motor technologies (in particular performance-optimized field-oriented control)! Get in touch!

Johannes Roßmann
Development of Electric Motors
Phone: +49 (89) 2872468-51
Dr. Thomas Leiber
Phone: +49 (89) 2872468-19