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This paper presents some of the modelling and experimental work being carried out at the University of Melbourne, in collaboration with CMC Research, on their new Scotch yoke engine concept. It begins with an overview of the engine, its compactness and friction advantages. The development of a one dimensional ‘squeeze film’ model is outlined and some simulation results are presented for both a motored and fired engine. A novel feature of the model is the introduction of an ‘un-filled factor’ to account for the dynamics of the oil film volume particular to this type of linear bearing. Experimental results are presented to highlight the important features and serve as a means of validating the model predictions. Comparisons show that the squeeze model correlates reasonably well with the experimental data and it is concluded that the current, flat, bearing design works by a predominantly squeeze film mechanism.

The Australian concept car "aXcessaustralia II" is a serial hybrid car of the so-called "New Generation Hybrids." Its internal combustion engine drives an electrical power generator. The wheels are driven by the electrical traction motor only, which receives its energy from a combination of batteries, capacitors and the electrical power generator. In a drivetrain, which consists of a combustion engine, a generator, a traction motor, two different systems for electrical energy storage and the necessary electronics to apply the most fuel efficient power strategy, all components require an extremely high degree of weight optimization to avoid offsetting the fuel savings achieved with the system by an increased overall vehicle weight. They also need to be extremely efficient in themselves.

The application of a Scotch Yoke crank mechanism to a reciprocating internal combustion engine reduces the engine's size and weight and, with the sinusoidal piston motion it provides, it changes the combustion parameters and simplifies the requirements for perfect balancing of the engine. This paper makes a theoretical comparison between conventional and Scotch Yoke engines with dimensional similarity of individual components where possible such as bore and stroke, and justifiable differences appropriate to each engine design such as cylinder bore off-set, piston height, connecting rod length etc. Included are variations related to differences in piston motion (true sinusoidal versus conventional) such as exhaust emissions and balancing requirements.