Control systems for friction clutch assemblies

Abstract

Control systems for a friction clutch mechanism and a hybrid coolant pump. Friction clutch assemblies are positioned inside the motor housing and include softening springs which minimize parasitic clutch power consumption. The control systems use PWM to control the operation of solenoids which in turn operate the friction clutch assemblies.

What is claimed is: 
     
         1 . A control system for a hybrid cooling pump, said hybrid cooling pump comprising: a pump housing member; a pulley assembly attached to said pump housing member; an impeller member positioned in said pump housing for pumping coolant; an impeller shaft connected to said impeller member; an electric motor positioned inside said pulley assembly and adapted to selectively rotate said impeller member; a friction clutch assembly positioned inside said pump housing member and adapted to selectively rotate said impeller shaft member; and
 wherein said pulley assembly and said electric motor operate separately to rotate said impeller member;   said control system comprising a solenoid for activating said friction clutch assembly; and   a drive controller for said solenoid, said controller disengaging said solenoid by operating at 100% pulse width modulation to provide full current to the solenoid, and said controller significantly reducing the pulse width modulation when said solenoid is disengaged in order to consume less current.   
     
     
         2 . The control system as described in  claim 1  wherein said friction clutch assembly comprises a compression spring member. 
     
     
         3 . The control system as described in  claim 2  wherein the amount of force necessary to compress the spring member lessens over displacement once it has reached a peak amount of force. 
     
     
         4 . The control system as described in  claim 3  wherein said compression spring member comprises a plurality of area members having openings therein and a plurality of deformable connecting members extending between and connecting together at least two of said area members. 
     
     
         5 . The control system as described in  claim 4  further comprising at least one ring member also connecting with a plurality of said area members. 
     
     
         6 . The control system as described in  claim 4  wherein an outer ring member and an inner ring member are provided, each of said outer and inner ring members connecting with separate pluralities of area members. 
     
     
         7 . The control system as described in  claim 2  wherein said compression spring member comprises a plurality of buckling beam spring members. 
     
     
         8 . The control system as set forth in  claim 1  wherein said friction clutch assembly comprises:
 a friction lining carrier member; 
 at least one friction lining member positioned on said friction lining carrier member; 
 a compression spring member fixedly attached to said friction lining carrier member; 
 a clutch carrier member fixedly attached to said compression spring member; and 
 a flux plate positioned between said clutch carrier member and said compression spring member and attached to said friction lining carrier member; 
 wherein said flux plate actuated by said solenoid can cause said compression spring member to compress. 
 
     
     
         9 . The control system as described in  claim 8  wherein said compression spring member has an outer ring member, an inner ring member and a plurality of deformable connecting members connecting together said inner and outer ring members. 
     
     
         10 . The control system as described in  claim 9  wherein said friction lining carrier member is attached to said outer ring member, and wherein said clutch carrier member is attached to said inner ring member. 
     
     
         11 . The control system as described in  claim 10  wherein said plurality of connecting members deform when said friction lining carrier member and said clutch carrier member are moved axially toward each other. 
     
     
         12 . The control system as described in  claim 8  wherein said compression spring member has a ring member and a plurality of deformable connecting members. 
     
     
         13 . The control system as described in  claim 8  wherein said compression spring member comprises a plurality of deformable connecting members. 
     
     
         14 . The control system as described in  claim 8  wherein the amount of force necessary to compress the spring member lessens over displacement once a peak amount of force has been reached. 
     
     
         15 . The control system as described in  claim 8  wherein said connecting members are positioned radially between said inner and outer ring members, and further comprising a plurality of tangential flex arms and radial gaps, said radial gaps being positioned between said flex arms and said outer and inner ring members. 
     
     
         16 . The control system as described in  claim 1  wherein said electric motor is a brushless electric motor. 
     
     
         17 . The control system as described in  claim 8  wherein said compression spring member comprises a plurality of buckling beam spring members.