length u201c l u201d and width u201c r u201d such that r d u2212 d 2 hereafter the two vanes are referred to as v 1 and v 2 as shown in fig3 the sleeves are depicted in fig1 liner the liner is depicted by hollow cylinder of inner diameter u201c d u201d length by u201c l u201d and thickness u201c t u201d with circular cover plates on both ends the cover plates have a hole of diameter u201c d u201d the whole diameter is same as that of sleeve 39 s outer diameter the liner is depicted in fig2 the v 1 s 1 fitting is here referred to as vs 1 the v 2 s 2 fitting is here referred to as vs 2 the vane and sleeve fitting is depicted in fig no 4 the half length of one edge of length u2018 l u2019 of v 1 v 2 is rigidly fixed on s 1 s 2 respectively such that a the plane of surface of v 1 v 2 is radial to s 1 s 2 b v 1 v 2 are fitted on one of the two ends of s 1 s 2 c half length of fixed edge projects out of the sleeve end the v 1 s 1 fitting is here referred to as vs 1 the v 2 s 2 fitting is here referred to as vs 2 the vane and sleeve fitting is depicted in fig4 0 vs 1 and vs 2 are fitted.