8. A VANE TYPE HYDRAULIC PUMP COMPRISING: A ROTOR HAVING A PLURALITY OF VANES MOUNTED FOR RELATIVE MOVEMENT, A STATOR PRESENTING A CAM SURFACE AND SIDE WALLS FOR ENGAGEMENT BY THE OUTER ENDS OF SAID VANES, LIQUID TRANSFER CHAMBERS DEFINED BETWEEN SAID VANES, A SUCTION PORT AND A PRESSURE PORT AT CIRCUMFERENTIALLY SPACED POSITIONS BETWEEN SAID ROTOR AND SAID CAM SURFACE, THE SPACE BETWEEN SAID PORTS DEFINING A TRANSFER ZONE, CLEARANCE GAPS BETWEEN SAID VANES AND SAID STATOR, MEANS FOR ROTATING SAID ROTOR SO AS TO TRANSFER LIQUID FROM SAID SUCTION PORT TO SAID PRESSURE PORT WHILE INCREASING THE PRESSURE ON THE LIQUID AT SAID PRESSURE PORT TO A PRESSURE SUBSTANTIALLY GREATER THAN THAT