摘要 |
A pump which can operate in a number of different modes, wherein each mode corresponds to a different output of the pump. The pump may have a plurality of pump chambers located within a pump housing. The pump chambers may be arranged in fluid communication with an inlet port and an outlet port. Each pump chamber may have a pumping device which draws in fluid from the inlet port during an intake stroke and pushes fluid through the outlet port during a discharge stroke. The pump may also have a plurality of electronically controlled valve assemblies which control the output of the pump. Each valve assembly can be selectively switched to a by-pass state for by-passing the fluid flowing from the pump chamber back to the inlet port during the discharge stroke of a pumping device. The pump may operate in a number of different modes which each have a distinct output. Each mode may be defined by which valves are chosen to be switched to their by-pass state. |