if now the circular slipper rings are moved to the right by the operating rod, through the casing from the telemotor rod, the the center of rotation of the slippers and plungers is at B which is eccentric to the center of the shaft, 0. This means the greatest distance the plunger gudgeons are from 0 is OG and the shortest distance is OF.With the direction os rotation as shown, in travelling round from G to F the plungers are moving in relative to the fixed central shaft and ports hence the top port T acts as a discharged.In completing the circular route from F back to G the plungers are moving