Dual actuating variable cam

Abstract

A variable camshaft timing system including a first camshaft phaser having an input that is configured to receive rotational force from a crankshaft and an output that is configured to link with a first camshaft of a concentric camshaft assembly to change the angular position of the first camshaft relative to a crankshaft; and a second camshaft phaser having an output that is configured to link with a second camshaft of the concentric camshaft assembly to change the angular position of the second camshaft relative to the crankshaft, wherein the first camshaft is concentrically positioned to the first camshaft and the first camshaft phaser is mechanically linked to the second camshaft phaser to communicate rotational force from the crankshaft to the second camshaft phaser through the first camshaft phaser and the mechanical link.

What is claimed is: 
     
         1 . A variable camshaft timing system, comprising:
 a first camshaft phaser comprising a hydraulically-actuated camshaft phaser having a first housing, an input that is configured to receive rotational force from a crankshaft, and an output that is configured to link with a first camshaft of a concentric camshaft assembly to change the angular position of the first camshaft relative to a crankshaft; and   a second camshaft phaser comprising a hydraulically-actuated camshaft phaser having a second housing and an output that is configured to link with a second camshaft of the concentric camshaft assembly to change the angular position of the second camshaft relative to the crankshaft, wherein the first camshaft is concentrically positioned to the second camshaft and the first camshaft phaser is mechanically linked to the second camshaft phaser to communicate rotational force from the crankshaft to the second camshaft phaser through the first camshaft phaser and the mechanical link.   
     
     
         2 . The variable camshaft timing system recited in  claim 1 , further comprising a flex plate that couples the first camshaft phaser to the second camshaft phaser.