Power driven fluid displacement apparatus

In a power driven fluid displacement apparatus comprising:

• a longitudinal shaft having a first and second end, said first end adapted to be rotatively effectively driven by a driving motor, said longitudinal shaft being provided with projecting blades including at least a first blade portion positioned on one side of said longitudinal shaft and a second blade portion positioned on the other side thereof in symmetrically balanced relationship and with each of said first and second blade portions having an outer pushing part provided with a leading edge and a trailing edge and an outer tip edge interconnecting said leading and trailing edges and being deflected axially forwardly from a true transverse plane perpendicular to said longitudinal shaft and twisted so as to have said leading edge positioned along an outwardly and axially forwardly inclined edge line axially forwardly displaced from a similar outwardly and axially forwardly inclined edge line coincident with the corresponding trailing edge;
• each of said pushing parts having a rear pushing surface inclined axially forwardly and rotatively forwardly in the direction of rotation toward said leading edge and inclined axially forwardly and outwardly in a radial direction away from said longitudinal shaft,
• said projecting blades being fixedly attached to the second end of said longitudinal shaft, the improvement comprising:
• a bar fixedly attached to the bottom of said projecting blades,
• said bar having longitudinally untwisted top and bottom surfaces and a first and a second pair of edges, said second pair of edges being longer than the first pair of edges,
• said bar being attached to said projecting blades such that the center of said projecting blades is directly over the center of said bar, wherein the top surface of said bar abuts said projecting blades,
• said second pair of edges being defined by parallel vertical planes,
• said first pair of edges defining free ends of said bar.