Axial flow rotor with downstream bearing wash flow

An implantable blood pump, comprising:

• a ferromagnetic impeller body having a bottom surface at a downstream end of the body and a central opening extending at least partially through the body from the bottom surface, the central opening centered about a rotational axis of the body, the rotational axis defining an axial direction;
• the body being configured to rotate about an element projecting from below the bottom surface into the central opening to drive a primary downstream blood flow along an exterior of the body to beyond a peripheral edge of the bottom surface and axially downstream from the impeller, the body including a bearing proximate a distal end of the element;
• the body configured to drive a secondary downstream blood flow through the central opening toward the bottom surface and then outwardly along the bottom surface to beyond the peripheral edge, the bottom surface include a plurality of axially protruding ridges defining at least one fluid channel, the plurality of axially protruding ridges being configured to drive the secondary downstream blood flow from the opening towards the peripheral edge;
• and
• the pump being configured to rotate the body about the axis and to drive the blood in a generally axial direction downstream from the impeller.