Rocker Motion-Powered Generators For Rocker-Mounted Electronic Devices

Abstract

An internal combustion engine has a valvetrain that includes a rocker arm assembly on which is mounted an electronic device and at least a part of a generator. The generator converts some of the mechanical energy that is transmitted through the rocker arm assemblies into electricity. That electricity may be used to power an electric latch, a transmitter, or another type of rocker arm assembly-mounted electrical device. Various generator configurations are described. In some configurations, the generator is piezoelectric. In other configurations, the generator is electromagnetic. In some configurations, the generator is driven by force transmitted by the rocker arm assembly from a cam. In some configurations, the generator is driven by vibrations.

1 . A valvetrain, comprising:
 a cam shaft on which is mounted an eccentrically shaped cam;   a poppet valve;   a rocker arm assembly configured to engage the cam as the cam shaft rotates and operative to actuate the valve;   a generator operative to convert mechanical energy into electric energy; and   an electrical device, which is distinct from the generator, mounted on the rocker arm assembly;   wherein a portion of the generator comprising a pole is mounted on the rocker arm assembly;   the generator is configured to power the electrical device, the configuration including an electrical connection between the electrical device and the pole; and the generator is driven by the cam.   
     
     
         2 . (canceled) 
     
     
         3 . A valvetrain according to  claim 1 , wherein:
 the generator is an electromagnetic generator comprising a coil and a magnet configured to move relative to one another in a first direction as the cam is rising off base circle and in the opposite direction as the cam is descending toward base circle; and   the coil is mounted to the rocker arm assembly.   
     
     
         4 . A valvetrain according to  claim 1 , wherein:
 the rocker arm assembly comprises a cam roller configured to follow the cam;   the generator is an electromagnetic generator comprising a coil and a magnet configured to undergo relative rotation in sync with the cam roller.   
     
     
         5 . A valvetrain according to  claim 1 , wherein the pole and the electrical device and are held in rigid relationship to each other through the rocker arm assembly. 
     
     
         6 . A valvetrain according to  claim 1 , further comprising an energy storage device selected from the group consisting of batteries and capacitors mounted on the assembly and electrically coupled to both the generator and the electrical device. 
     
     
         7 . A valvetrain according to  claim 1 , wherein the electrical device comprises a solenoid. 
     
     
         8 . (canceled) 
     
     
         9 . A valvetrain according to  claim 1 , wherein:
 the rocker arm assembly comprises an elephant's foot; and   the generator comprises a component mounted on the elephant's foot.   
     
     
         10 . A valvetrain according to  claim 1 , wherein:
 the rocker arm assembly comprises a first part mounted on a second part that is an axle, trunnion, or rocker shaft;   the mounting of the first part on the second part permits relative rotation of the first part and the second part; and   the generator comprises a first component coupled to the first part and a second component coupled to the second part.   
     
     
         11 . A valvetrain according to  claim 1 , wherein the generator comprises a piezoelectric material configured to undergo compression in response to the cam rising off base circle and expansion in response to the cam descending toward base circle. 
     
     
         12 . A valvetrain according to  claim 1 , wherein the rocker arm assembly is operative to transmit force from the cam by one or more pathways and the generator is a piezoelectric generator configured in one of those pathways. 
     
     
         13 . A valvetrain according to  claim 1 , wherein the generator is a piezoelectric generator positioned within a pathway along which the rocker arm assembly transmits mechanical energy from the cam shaft to a valve spring. 
     
     
         14 . A valvetrain according to  claim 1 , wherein:
 the assembly comprises a rocker arm and a fulcrum on which the rocker arm pivots; and   the generator is a piezoelectric generator configured to undergo a compressive force in proportion to force of the rocker arm on the fulcrum.   
     
     
         15 . (canceled) 
     
     
         16 . A valvetrain according to  claim 1 , wherein:
 the rocker arm assembly comprises a first part mounted on a second part that is an axle, trunnion, or rocker shaft; and   the generator is a piezoelectric generator positioned to transmit force between the first part and the second part.   
     
     
         17 . A valvetrain according to  claim 1 , wherein the generator is a piezoelectric generator positioned between a rocker arm and a lifter in a configuration enabling transmission of mechanical force between the rocker arm and the lifter to take place through the piezoelectric generator. 
     
     
         18 . A valvetrain according to  claim 1 , wherein:
 the generator is a bending force-driven piezoelectric generator operative to produce power when bent; and   the piezoelectric generator is coupled to bend in conjunction with a movement of the rocker arm assembly.   
     
     
         19 . (canceled) 
     
     
         20 . (canceled)