the device however is able to convert a lower pressure more effectively to output for example this can allow for a relatively loose fitting pressure seal to work effectively fig6 is a third embodiment of the present invention showing only the u201c cutout u201d section cutting through the cam non simultaneous engagement area 51 there is a guide cam assembly having a leading set of three cam arcs 611 and trailing set of three cam arcs 612 there is in the rotor a straight cam assembly having a leading set of six straight cam surfaces 621 and a trailing set of six straight cam surfaces 622 the cam arc centers 613 614 are equidistant from the shaft longitudinal center 61 and for the purpose of simplicity the cam arc centers 613 614 are arranged symmetrically with opposing cam arc centers 613 and cam arc centers 614 aligned it will be shown that the maximum angle u201c gamma u201d between two adjacent cam arc centers 613 or 614 and the radius of the cam arc 611 or 612 will determine the maximum radius of simultaneous engagement relative to the crank length this is the maximum radius through which the shaft may pass with clearance to rotate and also the minimum lever arm creating a force between arc cams 611 612 and straight cams 621 622 as measured from or eccentric bearing center 63 when the maximum angle between cam arc centers 613 614 measured from shaft longitudinal canter 61 is decreased for example by having more cam arcs 611 612 the length for which the straight cam surfaces 621 622 need to extend radially toward the hole 51 center decreases the effect of introducing an angle gamma.