Norman H. Beachley

EVALUATION OF THE FLYWHEEL DRIVE CONCEPT FOR PASSENGER VEHICLES

A flywheel to manage energy between a prime mover and a load has been used in many engineering applications. Automotive applications, however, pose a number of difficult problems which can be overcome only with proper design. Substantial mileage and performance improvements while meeting emission constraints can then be accomplished with the concept. An experimental flywheel car has been designed and built at the University of Wisconsin that has demonstrated a mileage improvement of about 50% over a corresponding production vehicle on the EPA/FUDC. With continued research and development gains of 100% appear feasible.

CONTINUOUSLY VARIABLE TRANSMISSIONS: THEORY AND PRACTICE

The five basic principles that can be used in the design of continuously variable transmissions (CVT) for motor vehicles are examined and compared. These include: hydrostatic, traction drive (V-belt and rolling contact), overrunning clutch, electric, and multispeed gearbox with slipping clutch. Appendix A discusses commercially available CVTs suitable for motor vehicles, and Appendix B describes research and development programs for CVTs.

A Critical Evaluation of the Geared Hypocycloid Mechanism for Internal Combustion Engine Application

The geared hypocycloid mechanism, a kinematic arrangement that provides a straight-line motion, can be used as the basis for an internal combustion engine. Its particularly attractive for small single cylinder engine applications where vibration is undesirable, and also for the uncooled «adiabatic engines», in which piston cylinder lubrication and friction are major concerns. The paper discusses the history of the concept, the limited engineering development that it has received, limitations and potential weak points of the design, and a presentation of design configurations that appear particularly attractive

Design Feasibility of a Free Piston Internal Combustion Engine/Hydraulic Pump

A direct acting free piston internal combustion engine/hydrostatic pump is analyzed. This device would take the place of a conventional engine-driven hydrostatic pump, and would be expected to offer significant advantages in cost, weight, and efficiency. The free piston configuration eliminates the need for a crankshaft-connecting rod system, and the comparable mechanism of the pump that converts rotary to reciprocating motion. Analysis of the design was done by computer simulation using a thermodynamic model of the combustion cylinder in combination with the system dynamics

Improving Vehicle Fuel Economy with Hybrid Power Systems

Hybrid vehicles, i.e., those containing two or more sources of power, have the potential of increased fuel economy under certain types of driving conditions. Systems currently being investigated include combinations of heat engines, electric drives, fly-wheels, and accumulators. In order to obtain fuel economy improvements over conventional vehicles, efficient components are required as well as a good system design. Hybrid powerplants appear more promising for heavier vehicles. /SAE/

Hydraulic Drive Systems and Potential Use for Automobiles and Airplanes

Utilization of hydrostatic drives for power transmission, along with hydropneumatic accumulator energy storage can provide significant opportunities for improvements in vehicle design. These advantages are particularly relevant when considering advanced concept vehicles such as flying automobiles. Research and development in this technology has primarily focused on the fuel economy improvements that can be achieved in automobiles using a hydrostatic transmission and hydropneumatic accumulator energy storage. The accumulator permits the engine power to be uncoupled from the road load, thus enabling the engine to be operated at a more efficient point. By using wheel drive units that can operate as either motors (when driving) or pumps (when braking), regenerative braking can also be achieved, with the energy stored in the accumulator. In addition to improved fuel economy, several other significant design opportunities can be exploited. The drivetrain concept that has been most

Design of a Modified Hypocycloid Engine

Abstract : The modified hypocycloid engine incorporates a unique geared drive that imparts straight-line, sinusoidal motion to the one-piece piston and rod assembly. These kinematic characteristics provide a variety of potential benefits not possible with traditional slider-crank kinematics. Perfect engine balance is achieved through the use of two sets of counterweights. The absence of piston side thrust promises reductions in piston assembly friction and piston slap, even with smaller piston skirts. Additional potential benefits include improved combustion characteristics and reduced piston manufacturing costs. Although simpler hypocycloid designs provide the same motion, the modified hypocycloid engine reduces gear and crankshaft loading. A description and design details of a prototype engine currently under construction are presented. Patented design improvements over previous hypocycloid designs are described. These improvements reduce crankshaft stresses, ensure a compact crankshaft with convenient assembly and disassembly, and control deviations from the desired straight-line piston motion that are caused by gear tooth backlash.

DESIGN CONSIDERATIONS FOR FLYWHEEL-TRANSMISSION AUTOMOBILES

The standard vehicle propulsion system and its controls are compared with a flywheel propulsion system. Different concepts of control and various system configurations are explored. Some considerations for the design of a general purpose automatic flywheel transmission vehicle are presented and discussed. Specifications required for a flywheel transmission system which can achieve substantial mileage improvements and provide high performance are presented.

A Technique for Obtaining an Engine Emissions Model Based on Continuous EPA-CVS Test Data and a Dynamic Vehicle Model

A new technique for obtaining engine emission flow rate maps has been developed. The maps are based on specific emissions data obtained on a continuous basis over a single EPA-CVS urban driving cycle test. The data are averaged for the various torque-speed ranges of the engine. It has been found that these dynamic average emission flow rate maps, which are functions only of engine torque and speed, allow instantaneous emissions to be fairly accurately predicted. /GMRL/

Techniques for improving the efficiency of agricultural fluid power systems

Techniques pour augmenter le rendement des systemes hydrauliques utilises sur le materiel agricole