that receives the o ring seal 114 for securing all of the housing sections together and retaining them in proper alignment are dowel pins 116 and 118 which are press fitted into through openings 120 and 122 as shown more clearly in fig1 12 14 and 16 the openings 120 in the housing sections are larger than the other openings 122 this being for the purpose of receiving different sized dowel pins for assuring proper alignment of the housing sections during assembly the chambers 64 and 92 for the gear pairs 24 and 26 respectively are shaped as shown in fig1 13 14 and 15 they are substantially identical except for the thicknesses each being formed of two circular sections which have the same diameter and which intersect these circular sections otherwise termed as gear pockets are indicated by the numerals 124 and 126 in fig1 and 128 and 130 in fig1 the centers of these gear pockets are common with the centers of rotation of the respective gears received therein it will be noted that the mid portions of the chambers 64 and 92 each have small curvatures 132 which are congruent and adjacent to the respective inlet and outlet ports 48 56 58 fig3 and 10 in the housing sections 14 and 22 as shown however with respect to the housing section 20 the curved.