The Design of an Engine-Flywheel Hybrid Drive System for a Passenger Car

Abstract

The quest to improve the fuel economy of General Motors passenger cars has led to the investigation of an engine-flywheel hybrid powertrain at the GM Research Laboratories (GMR). An engine-flywheel system was designed for a compact car and its performance was predicted analytically. The sytem was estimated to achieve an improvement in EPA composite fuel economy of 13 per cent ooer a 1984 production compact car. This margin of improvement was judged insuficient to justify the complex drivetrain, and, therefore, a prototype system was not built. However, the current potential of engine-flywheel hybrids for GM passenger car applications has been defined, and the technology areas requiring additional research attention have been identified.

Theoretical Study and Experimental Validation of a Hydrostatic Transmission Control for a City Bus Hybrid Driveline with Kinetic Energy Storage

“…Initially the electric motor EM (5) is used to accelerate the secondary KES2 (4) via V-belt coupling (6) till stable speeds are achieved. During this period the pressure relief valve (13) is kept fully open, thus separating the pump A7V (1) from the EM as the whole pump flow passes to the tank (T). The first main mode of the test stand operation, considered as regime A and shown in Figure 8, coincides with mode I (KES charge by ICE) of the bus hybrid system, and this mode starts on when the relief valve (13) is activated remotely to its preset.…”

“…Different types of continuously variable transmissions (CVT) are available, but the choice of energy device type is inevitably coupled with the choice of the transmission type according to the requirements for less or no energy conversion. The most appropriate and simplest CVT types of 2 of 22 KES utilization are mechanical ones, such as the V-belt drive [12,13], combined automated manual transmission (AMT) with belt variators as CVT [14], and AMT transmission with toroidal CVT [15], where the latter is the basis of London buses [16]. The weak point of such transmission configurations is the power flow limit through the CVT part, and as a consequence, the inability to use KES in its optimal efficiency range [17].…”

“…Comparative analysis results: approximate theoretical model-solid line; experimental data-"*".The test stand design requires KES2 (4) deceleration with EM (5) switched off, as the used pump A7V(1)is intended for open hydrostatic contour. The pressure relief valve(13) is kept fully open during this mode. This defines the zero speed of ω EM at the beginning of the second main mode as it is shown on…”

Feasibility Analysis and Performance Evaluation of a Novel Power-Split Flywheel Hybrid Vehicle

“…To avoid the use of multiple transmissions, 2-DoF FHV systems have been proposed [13][14][15][16][17][18][19]. The two-mode flywheel hybrid, introduced by General Motors (GM), includes five clutches and one CVT to implement a multi-mode 2-DoF FHV [13,14].…”

“…The two-mode flywheel hybrid, introduced by General Motors (GM), includes five clutches and one CVT to implement a multi-mode 2-DoF FHV [13,14]. The clutched flywheel transmission (CFT) is developed and added to the engine-CVT configuration [15].…”