The proprietary RETORQ Motors® electric traction motors-generators are more compact and lightweight than other traction motor technologies due to the unique design features of the RETORQ (REluctance TORQue) technology. The RETORQ motor technology is well known for its robustness, reliability and low cost features. The “grandad” technology of RETORQ motors technology is the well-known switched reluctance machine. RETORQ Motors company went a long way and made step-change improvements to the switched reluctance motor technology. State-of-the-art packaging and cooling design techniques have enabled RETORQ electric motors-generators achieve tenfold improvement of its performance metrics whilst completely eliminating the use of permanent magnets (PM) - as is seldom possible with the alternative motor technologies. The proprietary water-glycol based cooling technology enables RETORQ electric motors operate at substantially reduced temperatures even for the most demanding applications where low coolant flow rate and demanding duty cycles exclude alternative motor technologies. Key innovations of the RETORQ reluctance torque motors:

• Compact and lightweight RETORQ electric traction motors-generators based on proprietary REluctance TORQue motor technology
• RETORQ motors-generators offer lowest in class automotive traction system unit cost
• RETORQ technology delivers highest power-to-cost ratio electric traction motors
• RETORQ electric traction motors offer robustness, reliability, fault tolerance and low cost features not realisable with any other single electric motor technology
• RETORQ electric motors-generators achieve tenfold improvement of its performance metrics without permanent magnets
• State-of-the-art packaging and cooling techniques increase RETORQ electric traction motor output torque and power – making RETORQ machines suitable for most demanding automotive traction applications
• RETORQ electric motors enable lowest cost traction drive systems
• RETORQ electric motors are very cost-competitive compared with the permanent magnet based motor technologies
• Proprietary water-glycol based RETORQ cooling system enables demanding stop/start and high duty cycle performance at a reduced coolant flow rate

The proprietary RETORQ electric traction motors and generators are based on its predecessor switched reluctance machine technology without permanent magnets. RETORQ motors operate on the principle of REluctance TORQue also known as electromagnetic attraction and therefore require no permanent magnets (PM). Permanent magnet based electric motors can be as powerful as RETORQ motors however the PM machines suffer from the common failures of the permanent magnets making them expensive to maintain and repair. For this reason RETORQ motor technology is most suitable for applications which pose highest risk to the following failure modes:

• Demagnetisation failure of permanent magnet components due to high temperature
• Demagnetisation failure of permanent magnet components due to low temperature
• Demagnetisation failure of permanent magnet components due to repeated mechanical shock and vibration
• Failure of permanent magnet components due to mechanically induced brittle fracture
• Failure of permanent magnet components due to brittle fracture and or demagnetisation caused by environmental degradation such as corrosion/oxidation

None of the above listed failure modes of the PM motor technology are applicable to the permanent magnet-free RETORQ Motors® technology.

Further advantage of REluctance TORQue traction motors is that the machine phases are electrically independent. Therefore the RETORQ traction motor-generator operating with a faulty phase, for example a short circuit fault in the motor inverter, will produce output torque. The level of the output torque will be influenced by the severity of the fault, but will not prevent motor operation completely. The reliability and robustness of the reluctance torque motor technology therefore enables the RETORQ traction motors operate under most demanding duty cycles and in most demanding environments.

Key reliability and robustness features of the RETORQ traction motors:

• Short circuit fault-proof RETORQ electric traction motor architecture enables machine operation under short circuit fault conditions
• Short circuit fault-proof RETORQ electric traction motor architecture enables the limp-home capability to the automotive traction applications
• Liquid cooled RETORQ electric traction motors can operate under elevated temperatures for extended periods under electric fault conditions due to proprietary RETORQ motor electrical insulation technology

The manufacturability of the electric machines is of considerable importance for the medium to high volume applications - automotive traction motor industry being one example. For this reason RETORQ motor topology/architecture has enabled the low-cost yet cost-effective RETORQ motor technology most suitable for the medium to high volume applications. Highly automated and scalable manufacturing techniques have been adopted for the manufacture of the RETORQ automotive electric traction motors. Key manufacturing features of the RETORQ electric traction motors-generators:

• Low component count RETORQ electric traction motors offer economies of scale for the high volume automotive applications
• Standardisation of components: RETORQ electric traction motors use standard bearings, fasteners and connectors; this reduces the bespoke component manufacturing requirement to a minimum
• Highly automated assembly: RETORQ electric traction motors are designed for the automated assembly ensuring high quality finished product in quality-critical applications such as automotive traction motors
• Industry standard materials: RETORQ electric traction motors use only the industry standard copper/aluminium for the windings and only the electrical/silicon steel parts; ensuring secure supply of materials at stable market prices
• RETORQ electric traction motor technology reduces materials and manufacturing cost to a minimum – critically important consideration in the cost-sensitive high volume applications such as automotive industry

RETORQ automotive traction motors can be easily customized for the many different electric traction applications due to the scalable and compact slim line “pancake” topology/architecture. The compact slim line “pancake” style motor packaging is well suited for the engine bay integration with the existing internal combustion (IC) engine as a hybrid powertrain or as a pure electric powertrain with gearbox transmission. Key customization features of the RETORQ automotive traction motors:

• RETORQ electric motors offer scalable yet compact “pancake” style machines for the diverse range of traction applications where system volume and packaging constraints are specified and fixed
• RETORQ electric traction motors offer scalable output power machines from tens of kilowatts to hundreds of kilowatts output power
• Compact RETORQ electric traction motors are well suited for the existing engine bay integration with internal combustion engine as a hybrid traction powertrain or generator unit
• High power density RETORQ motors are well suited for the pure electric vehicle traction powertrains using suitable gearbox or single stage gearing
• High torque density RETORQ “pancake” style traction motors are stackable; enabling multiplicity of the output torque for the high torque requirements of the agricultural and off-road vehicle propulsion applications