Abstract: The present invention relates to a bubble elimination method in a medical centrifugal pump wherein a blood outlet 18 is directed upward so that a vertical line X passing through the enter point O of centrifugal pump main body 12 is positioned between two straight lines .alpha.,.beta. which respectively pass through center point O and a point A and center point O and a point B, points A and B lying on the circumference of centrifugal chamber 15 where its periphery connects with blood outlet 18, and a blood inlet 17 is directed upward at an angle which is larger than the angle which is formed between the axis and the inner peripheral surface of centrifuge chamber 15, blood outlet 18 and blood inlet 17 being supported in these states by a drive portion 13 of the centrifugal pump main body 12. After filling the centrifuge chamber with blood and liquid filling, the processes of low speed drive, drive halt and high speed drive are sequentially carried out to rotating body 23.

Abstract: A fluid displacement apparatus comprises a valve plate member dividing a compressor housing into a first chamber and a discharge chamber. A passage is formed in the valve plate member to allow communication between the first chamber and the discharge chamber. An elastic valve member disposed on the valve plate bends to open and close the end of the passage. The valve retainer member is secured to the valve plate together with the elastic valve member and has a curved end portion. A valve seat includes a recessed portion offset from an end surface of the valve plate. The recessed portion includes an inclined portion and a wall portion extending therefrom. The distance between the beginning of the curved portion of the valve retainer member and the securing means is greater than the distance between an edge of the recessed portion of the valve seat and the securing means.

Abstract: A screw compressor has a male rotor and female rotor rotatably engaging each other in a casing. The male rotor has a radius R and Z-number of helical convex teeth, each of which is chamfered on a leading edge of an end facing the discharge end of casing to allow lubricating liquid to escape from a space between rotor teeth during discharge stages of operation. This prevents drastic increases in pressure upon the bearings due to a liquid compression phenomenon. Thrust forces produced by the liquid against a flat chamfer surface prevent scoring of the edges of the rotors and thus permit designs with narrow gaps between the rotors and the casing to improve the efficiency of the compressor.

Abstract: The present invention relates to a liquid-ring pump which effectively dampens noise by providing a blocking element arranged in its compression space in the flow path between the mouth of its output port and the outlet opening of its discharge connection. The blocking element covers this outlet opening and has a flow-through opening. The cross-section of the flow-through opening automatically adapts to the quantity of medium delivered by the pump at any given time.

Abstract: A fluid pressure feeding apparatus for feeding cold water for cooling a mining pit into the pit and pumping water and muddy water heated within the mining pit onto the ground. A controller for switching a number of the operative chambers is provided to thereby perform a continuous operation.