Abstract: Valveless piston pumps are disclosed that are magnetically driven, thereby eliminating a troublesome dynamic seal used on conventional valveless piston pumps. An exemplary embodiment includes a housing defining a bore having a bore axis. A piston is situated in the bore so as to be movable in the bore in a reciprocating manner along the bore axis and in a rotational manner about the bore axis. A magnet is situated in the bore and is coupled to the piston. The magnet is engageable magnetically with a magnet-driving device configured to cause the magnet, and thus the piston, to move in the reciprocating manner and in the rotational manner. An exemplary magnet-driving device is a stator assembly.

Abstract: A system and a method are provided for velocity modulation to create pulseless delivery of a fluid by a pump, particularly a piston pump. The system and method require input of data, such as a user-entered dispense rate or analog current or voltage input proportional to a desired output rate. A timer or counter is pre-loaded from a lookup table stored in a processor. The time or counter is started and, upon detection of an overflow condition, the motor and table pointer are incremented one step. As a result, pulseless operation of a pump is achieved.