Mechanical drive for blood pump

Claim 1

A blood pump of an artificial heart comprising: a substantially hemispherical pump housing; a drive shaft extending into said housing; a rotatable flywheel disposed in said housing and having a diameter slightly less than the maximum inner diameter of said housing; meshing bevel gears disposed on said shaft and said flywheel for rotating said flywheel; a compound planetary gear set disposed within housing comprising a sun gear integral with said flywheel, a stationary ring gear affixed to said housing, compound planetary gears meshing with said sun gear and the ring gear, and a spider carrying said planetary gears and rotatable within said housing by said planetary gears at a speed less than the rotational speed of said flywheel; a single bevel gear secured to and rotatable by said spider; a pair of bevel gears meshing with said single bevel gear having their axis of rotation parallel to one another and rotatable by said single bevel gear; a rotatable crank arm attached to each of said pair of bevel gears; a pair of scotch yokes disposed within said housing with each of said yokes in contact with each of said cranks and vertically displaceable in response to the rotation of said cranks; a diaphragm disposed within said housing above said scotch yokes and defining with said housing a blood receiving chamber; and a pusher cup disposed intermediate said diaphragm and said scotch yokes and alternately displaceable by said scotch yokes upon the vertical displacement thereof by said crank for moving the diaphragm into said chamber and expelling blood therefrom and by the blood entering the chamber when said scotch yokes are not vertically displaced by said cranks.