Patent ID: 6120273
Filing Date: 2000-09-19
Classification: F01C

Abstract:
In a rotary vane pumping machine having a stator cavity communicating with a rotor, said rotor spinning around a rotor shaft axis which is a fixed rotational axis relative to said stator cavity, comprising:a pair of diametrically opposed vane slots in the rotor;a pair of vanes disposed in the pair of vane slots, each of the vanes having a base portion, a tip portion with a vane tip, and a protruding tab extending from an axial surface of the vane facing a common axial direction;a connecting means for connecting respective of the base portions of the pair of vanes; andan end plate disposed at one axial end of the pumping machine in the common axial direction, the end plate comprisinga fixed hub having an axis eccentric to the rotor shaft axis, anda translation ring rotating around the fixed hub having a bearing wall forming an outer radial edge of the translation ring, the bearing wall having a pair of linear segments, wherein the protruding tab extending from the axial surface of each of the vanes slidably contacts a respective one of the linear segments,wherein the stator cavity has a contoured sealing profile determined by a continuous path traced by tips of the pair of vanes as the rotor spins around the rotor shaft axis and the translation ring rotates around the eccentric fixed hub,wherein a radially inward surface of the protruding tab slidably contacts a respective one of the pair of linear segments, andwherein an inner length of the radially inward surface of the protruding tab, measured tangentially in a direction of rotor rotation, is greater than a thickness of the vane, measured tangentially in the direction of rotor rotation,further comprising a plurality of roller bearings disposed between the radially inward surface of the protruding tab and the pair of linear segments, whereby the radially inward surface radially constrains the entire plurality of roller bearings as the protruding tab reciprocates linearly along the bearing wall.