Pump with run-dry prevention for use on board a watercraft

Abstract

The present disclosure relates to a pump system including a pump and a liquid detection sensor or a flow sensor for sensing liquid presence or liquid flow. The water pump system also includes a controller that interfaces with the liquid detection sensor or flow sensor and uses data from the liquid detection sensor or the flow sensor to prevent the pump from being damaged under a run-dry condition.

What is claimed is: 
     
         1 . A pump system comprising:
 a pump;   a liquid detection sensor mounted to the pump for detecting the presence of liquid within the pump; and   a controller that interfaces with the liquid detection sensor and prevents power from being provided to a motor of the pump when the liquid detection sensor indicates insufficient liquid within the pump.   
     
     
         2 . The pump system of  claim 1 , wherein the pump is a magnetic drive pump. 
     
     
         3 . The pump system of  claim 1 , wherein the liquid detection sensor is an electrical conductivity sensor. 
     
     
         4 . The pump system of  claim 1 , wherein the liquid detection sensor is an ultrasonic sensor. 
     
     
         5 . The pump system of  claim 1 , wherein the liquid detection sensor is a magnetic field sensor. 
     
     
         6 . The pump system of  claim 1 , wherein the controller controls a power relay configured for connecting the motor to a power source and for disconnecting the motor from the power source. 
     
     
         7 . The water system of  claim 6 , wherein the controller is powered by the power source. 
     
     
         8 . The pump system of  claim 7 , wherein the controller is electrically isolated from the power relay and the power source. 
     
     
         9 . The pump system of  claim 8 , wherein the power source is an alternating current power source, and wherein an AC/DC converter is provided for converting alternating current from the power source to direct current provided to the controller. 
     
     
         10 . The pump system of  claim 1 , wherein the water pump system is part of an on-board water system of a watercraft. 
     
     
         11 . The pump system of  claim 1 , wherein the pump includes composite plastic/metal parts that are subject to heat damage if the pump is run when insufficient water is present in the pump. 
     
     
         12 . The pump system of  claim 1 , wherein the pump is a water pump. 
     
     
         13 . The pump system of  claim 1 , wherein the pump is a marine grade water pump. 
     
     
         14 . The pump system of  claim 1 , wherein the pump is a water pump adapted for pumping sea water. 
     
     
         15 . The pump system of  claim 1 , wherein the pump includes an impeller and a bearing that allows for rotation of the impeller relative to a housing of the pump, wherein the impeller is configured to rotate within a pump chamber to move liquid from a pump inlet through the pump chamber to a pump outlet under normal operation, and wherein the bearing is positioned to be exposed to and cooled by the liquid during normal operation of the pump. 
     
     
         16 . The pump system of  claim 15 , wherein the bearing is configured to allow the impeller to rotate relative to a shaft, wherein the shaft has a metal or ceramic construction, wherein ends of the shaft are supported by a housing of the pump, wherein the housing has a polymeric construction, and wherein during normal operation of the pump the shaft and portions of the housing supporting the ends of the shaft are exposed to the liquid in the pump. 
     
     
         17 . The pump system of  claim 16 , wherein the impeller is coupled to a plastic body supporting a plurality of magnets, wherein the bearing is mounted between the plastic body and the shaft, and wherein the magnets magnetically couple to a magnetic drive for driving rotation of the impeller. 
     
     
         18 . The pump system of  claim 1 , wherein the controller interfaces directly or indirectly with the liquid detection sensor. 
     
     
         19 . A pump system comprising:
 a pump;   a flow sensor for sensing liquid flow in the pump or through a flow path in fluid communication with the pump; and   a controller that interfaces with the flow sensor and terminates power to a motor of the pump when the flow sensor generates flow data indicative of the pump running dry.   
     
     
         20 . The pump system of  claim 19 , wherein the pump includes an impeller and a bearing that allows for rotation of the impeller relative to a housing of the pump, wherein the impeller is configured to rotate within a pump chamber to move liquid from a pump inlet through the pump chamber to a pump outlet under normal operation, and wherein the bearing is positioned to be exposed to and cooled by the liquid during normal operation of the pump. 
     
     
         21 . The pump system of  claim 20 , wherein the bearing is configured to allow the impeller to rotate relative to a shaft, wherein the shaft has a metal or ceramic construction, wherein ends of the shaft are supported by a housing of the pump, wherein the housing has a polymeric construction, and wherein during normal operation of the pump the shaft and portions of the housing supporting the ends of the shaft are exposed to the liquid in the pump. 
     
     
         22 . The pump system of  claim 21 , wherein the impeller is coupled to a plastic body supporting a plurality of magnets, wherein the bearing is mounted between the plastic body and the shaft, and wherein the magnets magnetically couple to a magnetic drive for driving rotation of the impeller. 
     
     
         23 . The pump system of  claim 19 , wherein the pump is a magnetic drive pump. 
     
     
         24 . The pump system of  claim 19 , wherein the controller controls a power relay configured for connecting the motor to a power source and for disconnecting the motor from the power source. 
     
     
         25 . The water system of  claim 24 , wherein the controller is powered by the power source. 
     
     
         26 . The pump system of  claim 25 , wherein the controller is electrically isolated from the power relay and the power source. 
     
     
         27 . The pump system of  claim 26 , wherein the power source is an alternating current power source, and wherein an AC/DC converter is provided for converting alternating current from the power source to direct current provided to the controller. 
     
     
         28 . The pump system of  claim 19 , wherein the water pump system is part of an on-board water system of a watercraft. 
     
     
         29 . The pump system of  claim 19 , wherein the pump includes composite plastic/metal parts that are subject to heat damage if the pump is run when insufficient water is present in the pump. 
     
     
         30 . The pump system of  claim 19 , wherein the pump is a water pump. 
     
     
         31 . The pump system of  claim 19 , wherein the pump is a marine grade water pump. 
     
     
         32 . The pump system of  claim 19 , wherein the pump is a water pump adapted for pumping sea water. 
     
     
         33 . The pump system of  claim 19 , wherein the controller interfaces directly or indirectly with the flow sensor.