Abstract: A positive displacement pump apparatus includes a housing formed of a housing wall including a wall portion; a pump center line; a pump drive shaft extending through the wall portion coaxially with the pump center line and having a terminus within the housing adjacent the wall portion; a rotatable disc disposed in the housing adjacent the wall and secured to the terminus to be rotated by the drive shaft about the pump center line; and a vane mounted eccentrically on the disc for travel along a circular arc as the disc rotates. The vane has a vane axis about which the vane rotates relative to the disc; and two opposite, axially spaced first and second radial sides. The vane is mounted on the disc at the first radial side. The vane further has two opposite, radially spaced axial sides. The distance of the vane axis to either of the axial sides is greater than the distance from the pump center line to the vane axis.

Abstract: A positive displacement pump apparatus includes a housing formed of a housing wall including a wall portion; a drive shaft extending through the portion and having a terminus within the housing adjacent the wall portion; a rotatable disc disposed in the housing adjacent said wall and being secured to the terminus to be rotated by the drive shaft; and a vane mounted eccentrically on the disc for travel along a circular arc as the disc rotates. The vane is rotatable about a vane axis relative to the disc. Further, a gearing is provided in the housing adjacent the wall portion for coupling the vane with the drive shaft to effect rotation of the vane about the vane axis, whereby the vane moves, in the circular arc, through a positive displacement portion of movement and a non-positive displacement portion of movement.