A 48-400V Off-Axis P2 Hybrid module with minimal impact on powertrain length Joint development between Volvo Cars and BorgWarner

摘要

Among P0-P4 hybrid configurations the P2 layout enables the maximum benefit in cost-effective CO_2 reduction, because the engine can be disconnected, while the e-machine still uses the ratios of the gearbox. P0-P4 positions are named according to the position of the emachine, as shown in Figure 1. However, for transverse powertrains it has proven difficult to package the necessary components without moving the engine and the gearbox apart. This presents major problems when the powertrain has no space to grow in the axial direction, and this has led OEMs to conclude that a P2 architecture is simply not possible for some powertrains. Further obstacles are encountered in designing and packaging a suitable battery, particularly at 48V, close enough to the e-machine to minimize electrical losses. A revolutionary solution has been created in a joint engineering project between Volvo Car Corporation (Volvo Cars) and BorgWarner, planned for series production from beyond 2020. It is a P2 hybrid with a chain-driven off-axis e-machine, which has been prototyped and tested in two versions - 48V (15 kW) and 350 V (65 kW), together with Volvo Cars unique 48V Li-ion battery, DC-DC converter and cooling system. The starter, alternator and 12V battery are deleted, and the AC pump is relocated to the P2 location, allowing the entire FEAD to be removed. The battery system is packaged in the engine compartment, close to the e-machine. The P2 module fits Volvo Cars entire engine range and transmission range, without the need to move the engine and transmission apart - an achievement unique in the automotive industry, and one that would be unlikely to occur except through close collaboration between an OEM and a system supplier. Volvo Cars and BorgWarner collaborated under a novel Joint Development Agreement, whereby both companies are free to use the technology both with each other, and with other suppliers and OEMs.