Abstract
A methodology to design tight running clearance between rotor and chamber in a trochoidal-type machine is presented. A mathematical model to describe the running clearance is developed. Only kinematic design parameters are considered. The effect of the mean values and tolerances of the design parameters on the running clearance is studied by applying robust design. Mean values of design parameters which provide running clearance to be less sensitive to the tolerances are obtained. The effect of the upper bound of the running clearance on the tolerance is also studied by applying the probabilistic optimal design. Optimum tolerances which minimize a cost function are obtained. Therefore, one can apply this methodology to design running clearance by choosing appropriate mean values and tolerances of the design parameters.