| 摘要 |
A fluid pump assembly having a body provided with a fluid chamber and a passage having an orifice, the passage connecting the chamber to a conduit carrying a pressurized flow of fluid. Pump apparatus has an inlet connected to a fluid additive supply, and an outlet which communicates with the conduit for feeding the fluid additive to the conduit. Control apparatus includes a dump passage communicating with the chamber and has a cross section larger than the orifice. A dump valve controls the flow of fluid through the dump passage to regulate the fluid pressure in the fluid chamber, and motor apparatus operatively connects the pump apparatus and the dump valve. The motor apparatus is responsive to the fluid pressure in the fluid chamber for operating the dump valve and actuating the pump apparatus to pump fluid additive through the outlet. The motor apparatus includes a flexible motor element subject to fluid pressure in the fluid chamber, permanent magnets attached to and movable with the flexible motor element, and a ferrous plunger operatively attached to the dump valve. The flexible motor element moves the permanent magnets in a first direction to open the dump valve, and in an opposite second direction to allow a spring to close the dump valve. The pump assembly includes a piston rod operatively connected to and extending from one side of the flexible motor element. The rod extends to pump cylinder where the reciprocating motion imparted by the flexible motor element is used to draw additive fluid into the pump inlet and out of the pump outlet to provide the fluid additive to the conduit.
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