Hybrid electromechanical coolant pump with base flow and peak flow

Abstract

The invention relates to a coolant pump having an impeller which is arranged on a pump impeller shaft and having a drive device for the impeller, which drive device has a mechanical drive and an electric-motor drive. The impeller shaft is divided into a driving section and a driven section, and an openable and closable clutch is arranged between the driving section and the driven section.

What is claimed is: 
     
         1 . A coolant pump for rotating an impeller shaft comprising:
 a housing member having a first end and a second end;   an impeller shaft member positioned in said housing member;   an impeller member positioned externally to said first end of said housing member and connected to one end of the impeller shaft member and rotatable therewith;   a pair of first bearing members positioned in said housing member and positioned on said impeller shaft to allow rotation of said impeller shaft in relation to said housing member;   a pulley member positioned adjacent said second end of said housing member;   a second bearing member positioned in said housing member to allow rotation of said pulley member relative to said housing member;   a mechanical drive body member positioned in said housing member and having a first end and a second end, said first end being fixedly attached to said pulley member; wherein said mechanical drive body member is rotatable with said pulley member;   an electric motor having a rotor member and a stator member, said electronic member positioned in said housing member;   said rotor member being fixedly connected to said impeller shaft member and rotatable therewith; and   an electromechanical clutch mechanism positioned in said housing between said second end of said mechanical drive body member and said electronic motor;   wherein activation of said electromechanical clutch mechanism prevents said mechanical drive body member from rotating said impeller shaft member; and   wherein deactivation of said electromechanical clutch mechanism couples said mechanical drive body member to said impeller shaft member, thereby rotating said impeller shaft member at the rotation speed of said pulley member.   
     
     
         2 . The coolant pump as described in  claim 1  wherein said electric motor is a brushless DC motor. 
     
     
         3 . The coolant pump as described in  claim 1  wherein said electromechanical clutch mechanism is deactivated when the impeller shaft member is rotating at a speed greater than a predetermined speed threshhold. 
     
     
         4 . The coolant pump as described in  claim 3  wherein said speed threshold is about 150 rpm. 
     
     
         5 . The coolant pump as described in  claim 1  wherein said rotor member is positioned between said pair of first bearing members. 
     
     
         6 . The coolant pump as described in  claim 1  wherein said electromechanical clutch mechanism is deactivated when the power to the electric motor is greater than a predetermined power threshold. 
     
     
         7 . The coolant pump as described in  claim 6  wherein said predetermined power threshold is about 1 kW. 
     
     
         8 . The coolant pump as described in  claim 1  wherein said electromechanical clutch mechanism comprises a friction clutch mechanism, an armature member and a solenoid member. 
     
     
         9 . The coolant pump as described in  claim 1  further comprising a Hall effects sensor. 
     
     
         10 . A coolant pump comprising:
 a pump wheel which is arranged on a pump wheel shaft;   a drive device for said pump wheel, said drive device having a mechanical drive and an electric-motor drive;   said pump wheel shaft being divided into a driving section and a driven section; and   an openable and closable clutch positioned between said driving section and said driven section;   wherein when said driven section is separated from said mechanical drive and the driving section, said pump wheel can be driven solely by said electric-motor drive.   
     
     
         11 . The coolant pump as set forth in  claim 1 , wherein said mechanical drive comprises a belt-pulley drive. 
     
     
         12 . The coolant pump as set forth in  claim 1 , wherein said driven section comprises said electric-motor drive. 
     
     
         13 . The coolant pump as set forth in  claim 1 , wherein said electric-motor drive comprises a brushless direct-current motor. 
     
     
         14 . The coolant pump as set forth in  claim 1  wherein said electric-motor drive has a rotor member which is positioned in said driven section, and a stator member which is positioned around said rotor member wherein said rotor member and said stator member are positioned concentrically with respect to one another and in a housing. 
     
     
         15 . The coolant pump as set forth in  claim 1  wherein said clutch comprises an electromagnetic clutch. 
     
     
         16 . The coolant pump as set forth in  claim 1  wherein said electric-motor drive is regulated by an electronic regulating device. 
     
     
         17 . The coolant pump as set forth in  claim 1  further comprising bearing for mounting said pump wheel shaft, said bearings having rotating inner rings. 
     
     
         18 . The coolant pump as set forth in  claim 1  wherein said electric-motor pump, which is formed by said electric-motor drive and by said pump wheel, provides a basic coolant flow, and wherein said mechanical pump is formed by said mechanical drive and said pump wheel and can be coupled by said clutch in order to deliver a maximum cooling power. 
     
     
         19 . The coolant pump as set forth in  claim 18  wherein said electric-motor pump and said mechanical pump are arranged in series. 
     
     
         20 . The coolant pump as set forth in  claim 1  wherein said mechanical drive and/or said electric-motor drive, can be decoupled from said driven section. 
     
     
         21 . The coolant pump as set forth in  claim 1  wherein said mechanical drive is coupled to said driven section when the electric-motor drive is not supplied with current. 
     
     
         22 . The coolant pump as set forth in  claim 1  wherein when said driven section ( 11 ) is coupled to said mechanical drive and said driving section by said clutch, said pump wheel is driven solely by the mechanical drive and said electric-motor drive is deactivated.