Electric camshaft phase-shifter with single shaft

Abstract

A regulating device for the continuous phase-shifting of the angle of rotation of a camshaft controlling the gas exchange valves of an internal combustion engine with respect to a driving element, notably a chain or belt, includes an electric regulating motor coupled to a reduction gearbox with three inputs/outputs comprising an external ring gear, an input element and an outer disc, the external ring gear being carried by the drive element, the outfit disc being secured to the camshaft. This device includes a single shaft inside the stator of the electric motor, the single shaft supporting the input element of the reduction gearbox and the rotor of the electric motor.

1 . A regulating device for continuous phase-shifting of an, angle of rotation of a camshaft ROM controlling the gas exchange valves of an internal combustion engine with respect to a chain or a belt drive element, the device comprising a brushless electric regulating motor including a stationary stator with respect to an external ring gear, with the engine being coupled to a reduction gearbox with three inputs/outputs comprising an external ring gear, an input element and an output disc), with the external ring gear being driven by the drive element, with the output disc being secured to the camshaft, a single shaft inside the stator of the electric motor, with the electric motor comprising a rotor secured to the single shaft so that the single shaft supports the rotor of the electric motor and the input element of the reduction gearbox. 
     
     
         2 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , wherein:
 the reduction gearbox is a trochoidal reduction gearbox; and   the axial single shaft supports the eccentric(s) enabling a reduction of the trochoidal type.   
     
     
         3 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 2 , wherein the inner surface of the external ring gear has a tubular toothed path meshed with one or more toothed wheel(s) mounted on the eccentrics having bores with a circular cross-section distributed over the annular area of the toothed wheel, and the trochoidal reduction gearbox comprising a set of pins having a section smaller than that of the bores, with the pins being secured to the output disc and passing through the bores to ensure the transmission of the motion between the eccentrically moving toothed wheel and the output disc. 
     
     
         4 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , wherein:
 the reduction gearbox is an epicyclic reduction gearbox; and   the axial single shaft carries the inner sun gear.   
     
     
         5 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 4 , wherein the inner surface of the external ring gear has a tubular toothed path meshed with one or more satellite(s), with the satellites being rotatable about pins secured to the output disc to ensure the transmission of the motion between the satellites and the output disc. 
     
     
         6 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , wherein the single shaft has a through bore. 
     
     
         7 . A regulating device for the continuous phase-shifting of the angle of rotation of camshaft according to  claim 6 , wherein the output disc is secured to the camshaft by a screw having a thread matching the internal thread of the camshaft, and bearing against a radial shoulder of the output disc. 
     
     
         8 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , wherein the electric motor is enclosed in an outer casing having a housing receiving a guide element of the single shaft. 
     
     
         9 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 8 , wherein the stator of the electric motor is overmolded and secured to the outer casing. 
     
     
         10 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , wherein the electric motor comprises a printed circuit supporting the electronic components for steering and powering the electric coils carried by the stator. 
     
     
         11 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , further comprising at least one position sensor delivering a signal according to the angular position of the output disc. 
     
     
         12 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , further comprising at least one position sensor delivering a signal according to the angular position of the external ring gear. 
     
     
         13 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 12 , wherein the pins are engaged, at their free ends, by a pin-holder provided with a permanent magnet positioned opposite a magneto-sensitive probe forming the position sensor with the magnet. 
     
     
         14 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 1 , wherein the electric motor has an outer casing having an outer surface matching a housing provided on the cylinder head of the internal combustion engine. 
     
     
         15 . A regulating device for the continuous phase-shifting of the angle of rotation of the camshaft according to  claim 14 , wherein the outer casing has fastening elements for attaching on the cylinder head of the combustion engine.