Blood pump devices having improved rotor design are provided herein. Such blood pump devices include rotors having cantilevered support through a sealed mechanical bearing disposed outside a blood flow path of the device so as to avoid thrombus formation caused by blood contact with the bearing. The bearing means can be rotatably coupled with a proximal portion of the rotor shaft extending outside the fluid path, while a stator drives rotation of the rotor shaft so that one or more rotor blades on a distal portion of the rotor force blood flow through the device. The bearing means may include one or more radial bearings on a proximal portion of the rotor shaft that are isolated from the blood flow path by one or more rotary seals.