초록 ▼

A fluid pumping apparatus (10) includes a soft start valve (16) coupled with the outlet of a pump (14) driven by an electric motor (12) for reducing the startup current of the motor (12). The preferred valve (16) includes a fluid chamber (32), a valve operator in the nature of a ball (22) shiftable

A fluid pumping apparatus (10) includes a soft start valve (16) coupled with the outlet of a pump (14) driven by an electric motor (12) for reducing the startup current of the motor (12). The preferred valve (16) includes a fluid chamber (32), a valve operator in the nature of a ball (22) shiftable in the chamber (32) between the inlet (36) and a valve seat (48), and a biasing assembly (24) including an axially shiftable rod (54) and a spring (56) for biasing the rod (54) against the ball (22) in order to bias the ball (22) toward the chamber inlet (36). Upon startup, the valve (16) provides a reduced start pressure, less than the pump pressure under load, at the inlet (36) as the operator (22) moves toward the seat (48). The chamber (32) presents a volume sufficient for the valve (16) to provide the start pressure long enough for the motor (12) to achieve synchronous speed, thereby reducing motor startup current.

대표청구항 ▼

[ What is claimed is:] [1.] A soft start valve for use with a fluid pump coupled with an electric motor for operation thereby, the pump having a pump outlet and operable to generate a pressure under load at the outlet, the motor being subject to startup current upon startup to operate the pump, said

[ What is claimed is:] [1.] A soft start valve for use with a fluid pump coupled with an electric motor for operation thereby, the pump having a pump outlet and operable to generate a pressure under load at the outlet, the motor being subject to startup current upon startup to operate the pump, said valve comprising:a valve body having walls defining a fluid chamber having an inlet configured for fluidically coupling with the pump outlet to receive fluid therefrom and defining a valve seat spaced from said inlet;a valve operator positioned in said chamber and shiftable therein between said inlet and said seat, said operator and walls being configured to provide a fluid seal therebetween; andbiasing means biasing said operator towards said inlet to provide a start pressure, less than the pump pressure under load, at said inlet and thereby at said pump outlet during startup and during shifting of said operator toward said seat,said chamber presenting a volume sufficient for said valve to provide said start pressure long enough for the motor to begin rotation during startup in order to reduce the startup current.