Fluid dispenser

摘要

A fluid dispenser for high viscosity fluid is driven by two electric motors. The rotary electric motor or actuator (1) rotates the main shaft (2) relative to cylinder (4). The stationary cylinder contains the inlet opening (8) and the discharge nozzle (10). The rotary electric motor or actuator (12) contributes to the rotation of the main shaft (2). The permanent magnet (21) applies a magnetic field to the Giant-magnetostrictive rod (19), which contracts and expands the rod to reciprocate the main shaft. A displacement sensor (28) measures the combination of rotary and reciprocating motion on the grooved part of the shaft (4) extending into the pumping chamber (7). For small pumping volumes (gaps in the order of 2,5 micrometers) the sealing pressure becomes larger than the pumping pressure, consequently the pumping action stops, which makes valves superfluous.