September 12, 2017
Rheinmetall Automotive develops drive system and energy storage unit for electric vehicles
Rheinmetall Automotive, the first-tier auto-industry supplier and member of the Technology Group Rheinmetall, is taking account of the increasing electrification of drivelines in its own product range. Among the products developed by the Company to this end area new kind of modular battery pack and a 90-kW electric drive unit. The new systems are currently installed in a test/demonstration vehicle based a subcompact car.
Rheinmetall Automotive can draw ondecades of engineering expertise in electric drive systems for auxiliary vehicle assemblies. Back in 2004 and through its Pierburg subsidiary, it had developed the first all-electric coolant pump for the main cooling system, which was then successfully installed and launched in the six-cylinder BMW engines.
An electrically commutated water-recirculation pump also developed by Pierburg, at its location in Hartha, Saxony, and launched in 1995 has meanwhile exceeded the mark of 50 million units produced and is installed in autos and other equipment by the world’s foremost manufacturers and suppliers. Other new additions to the lineup include the electric motor housings and battery boxes shortly to be series-manufactured in aluminum by Rheinmetall Automotive for international OEMs. The Company’s product range for electric mobility is supplemented by electric oil and vacuum pumps, electric coolant valves and actuators, an electric air-conditioning compressor along with heat pump module, as well as special lightweight components in aluminum.
In developing its new electric mobility products, Rheinmetall Automotive has quite intentionally opted for the areas of energy storage and electric drive systems plus their peripherals. In the case of battery packs, it is pursuing a strategy that attracts many OEMs by allowing the integration and thermal conditioning of a variety of battery cell types. Concurrently, it is introducing its own electric drive system with specific performance characteristics.
Underfloor battery packssafely protected
In the design of the new battery pack, Rheinmetall Automotive has worked from the premise that future electric vehicles and hybrids will largely use underfloor batteries which do not diminish the vehicle’s loading capacity to any major degree while offering advantages in terms of weight distribution and possible integration with the vehicle’s structure.
The basic structure of the battery pack developed by Rheinmetall Automotive for these applications is made from aluminum into which customer-specific battery modules can be integrated. The packs have their own cooling system and are shielded from intrusion by a composite-fiber structure developed by an affiliate within the Rheinmetall Group specializing in protection systems.
The arrangement is remarkable for its high energy density in relation to weight and, thanks to its compact footprint, permits very flexible and wide-ranging use in electric vehicles.
Electric motor with concentrated winding
The new drive unit is a synchronous permanent-magnet motor reflecting Rheinmetall Automotive’s many years of experience and expertise in high-volume production technology.
The 90-kW high-voltage motor is of polyphase design and features a concentrated winding for optimum space utilization. On Rheinmetall's test/demonstration vehicle the motor is coupled with a single-stage gear unit.
The drive system to be manufactured by Rheinmetall is adaptable by output and torque characteristics. The present design is tailored to smaller-sized vehicles, however the system’s scalability allows its use in larger ones, too.
Test/demonstration model with system potential
The battery pack of Rheinmetall Automotive’s test/demonstration vehicle on the basis of a FIAT 500 has a storage capacity of 29 kW/h.
With the new electric motor, the vehicle reachesa top speed of 135 km/h and a range of up to 275 km. These parameters are achieved without encroaching on the luggage or the passenger compartment space normally available on the series version of this vehicle.
Rheinmetall Automotive perceives this configuration tailored to future electric vehicles as a possible series-production project while allowing, of course, other arrangements to be assembled to address customer wishes.