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With the increasing demand for efficient & clean transport solutions, applications such as road transport vehicles, aerospace and marine are seeing a rise in electrification at a significant rate. Irrespective of industries, the main source of power that enables electrification in mobility applications like electric vehicles (EV), electric ships and electrical vertical take-off & landing (e-VTOL) is primarily a battery making it fundamentally a DC system. Fast charging solutions for EVs & e-VTOLs are also found to be DC in nature because of several advantages like ease of integration, higher efficiency, etc. Likewise, the key drivers of the electric grid are resulting in an energy transition towards renewable sources, that are also essentially DC in nature. Overall, these different business trends with their drivers appear to be converging towards DC power systems, making it pertinent.

The automotive industry has seen accelerating demand for electrified transportation. While the complexity of conventional ICE vehicles has increased, the powertrain still largely consists of a mechanical system. In contrast, vehicle architectures in electrified transportation are a complex integration of power electronics, batteries, control units, and software. This shift in system architecture impacts the entire organization during new product development, with increased focus on high power electronic components, energy management strategies, and complex algorithm development. Additionally, product development impact extends beyond the vehicle and impacts charging networks, electrical infrastructure, and communication protocols. The complex interaction between systems has a significant impact on vehicle safety, development timeline, scope, and cost.

Compared to the internal-combustion-engine (ICE) vehicles on the road today, Electric Vehicles (EV) deliver more torque to vehicle wheels, and require smaller driveline packaging envelopes. Current differentials use asymmetrical ring gears with differential housings that are roughly a third of the tire outside diameter. New differential architecture concepts are shown here to deliver more torque to the wheels, while decreasing the height of the differential as much as fourfold. Most EV’s are driven by one or more torsion motors, delivering torque to the left side and the right side of the EV’s at different speeds during a vehicle turn, or a wheel “spinout.” At low speeds, the EV motors deliver more torque to the wheels than comparably sized ICE vehicles, so EV differentials must be built stronger and stiffer to manage the distribution of available drive torque.

Fuel economy is one of the major challenges for both on and off-road vehicles. Inefficient engine operation and loss of kinetic energy in the form of heat during braking are two of the major sources of wasted fuel energy. Rising energy costs, stringent emission norms and increased environmental awareness demand efficient drivetrain designs for the next generation of vehicles. This paper analyzes three different types of powertrain concepts for efficient operation of a forklift truck. Starting from a conventional torque convertor transmission, hydrostatic transmission and a hydraulic hybrid transmission (Eaton architecture) are compared for their fuel economy performance. Eaton hydraulic hybrid system is seen to perform much better compared to other two architectures. Improved fuel economy is attributed to efficient engine operation and regeneration of vehicle kinetic energy during braking.

Recent studies have shown that hydraulic hybrid drivelines can significantly improve fuel savings for medium weight vehicles on stop-start drive cycles. In a series hydraulic hybrid (SHH) architecture, the conventional mechanical driveline is replaced with a hydraulic driveline that decouples vehicle speed from engine speed. In an effort to increase the design space, this paper explores the use of a fixed displacement checkball piston pump in an SHH driveline. This paper identifies the potential life-limiting components of a fixed displacement checkball piston pump and examines the likelihood of surface fatigue in the check valves themselves. Numerical analysis in ABAQUS software suggests that under worst case operating conditions, cyclic pressure loading will result in low-cycle plastic deformation of check valve surfaces.

A number of different data networks have been implemented for electronic control unit communication in vehicles to date. Each network serves a particular need, such as low-cost networking of cab components or high-speed networking of powertrain components. Although each communication network performs its original purpose, the different communication networks, especially those using hardware-based messaging protocols, are expensive to integrate for information sharing and are not readily upgradeable with new messages. This is complicated by the growing number of different communication networks for vehicles, often driven by OEM and supplier technology consortiums rather than by end-user requirements. The result is added vehicle-support costs for the OEM, dealership and customer to maintain multiple networks.

Car hauler ramps have historically been hydraulically positioned via banks of manual control valves that provide limited operator visibility and flexibility. On some enclosed type haulers, manual valves are not feasible. An electro-hydraulic system has been developed utilizing on/off solenoid valve stacks. A handheld control unit with a membrane switch pad communicates with a valve interface module near each valve stack. The handheld unit and the interface modules each have microprocessor circuitry to provide intelligent distributed control. Self monitoring circuitry provides safety features and system diagnostics. Wiring harness assemblies connect the valve stacks to the interface modules. A retractile cable from the handheld unit to the trailer allows improved operator mobility and visibility. An infrared wireless interface between the trailer and handheld unit will also be available.