Orbital Tensioner

Abstract

An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.

We claim: 
     
         1 . An orbital tensioner comprising:
 an annular base;   a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A);   a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A);   a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm;   a torsion spring biasing the pivot arm in a first direction;   the ball bearing having a first race and a second race;   the ring fixed to the first race;   the annular base fixed to the second race; and   a damping mechanism frictionally disposed between the ring and the base.   
     
     
         2 . The orbital tensioner as in  claim 1 , wherein the ball bearing is staked to the ring. 
     
     
         3 . The orbital tensioner as in  claim 1 , wherein the ball bearing is staked to the base. 
     
     
         4 . The orbital tensioner as in  claim 1 , wherein the damping mechanism comprises a friction member and a spring. 
     
     
         5 . The orbital tensioner as in  claim 1 , wherein the ball bearing comprises a double row bearing. 
     
     
         6 . The orbital tensioner as in  claim 1 , wherein the ball bearing is a sealed bearing. 
     
     
         7 . The orbital tensioner as in  claim 4 , wherein the spring comprises a wave spring. 
     
     
         8 . The orbital tensioner as in  claim 1 , wherein the ball bearing first race is an inner race. 
     
     
         9 . The orbital tensioner as in  claim 1 , wherein the ball bearing first race is an outer race. 
     
     
         10 . An orbital tensioner comprising:
 an annular base;   a ring rotationally engaged with the annular base with a ball bearing, the ring having a ring axis of rotation (A-A);   a first pulley journalled to the ring and having a first pulley axis of rotation (B-B) that is offset from the ring axis of rotation (A-A);   a pivot arm pivotally mounted to the ring, the pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm;   a torsion spring biasing the pivot arm in a first direction;   the ball bearing having a first race and a second race;   the ring staked to the first race;   the annular base staked to the second race; and   a damping mechanism frictionally disposed between the ring and the base.   
     
     
         11 . The orbital tensioner as in  claim 10 , wherein the ball bearing is a double row bearing. 
     
     
         12 . The orbital tensioner as in  claim 10 , wherein the ball bearing is a single row bearing. 
     
     
         13 . The orbital tensioner as in  claim 12 , wherein the single row bearing is a deep groove single row bearing. 
     
     
         14 . The orbital tensioner as in  claim 11 , wherein the damping mechanism comprises a wave spring and friction element. 
     
     
         15 . An orbital tensioner comprising:
 a base;   a ring, the ring and base journalled together on a ball bearing, said ring having a ring axis of rotation (A-A);   a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A);   a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) is offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm;   a torsion spring biasing the pivot arm in a first direction; and   a damping mechanism frictionally disposed between the ring and the base.   
     
     
         16 . The orbital tensioner as in  claim 15 , wherein the ball bearing comprises a sealed double row bearing. 
     
     
         17 . The orbital tensioner as in  claim 15 , wherein the ball bearing comprises a sealed deep groove single row bearing. 
     
     
         18 . The orbital tensioner as in  claim 15 , wherein the damping mechanism comprises a wave spring and a friction element. 
     
     
         19 . The orbital tensioner as in  claim 15 , wherein the base and the ring are staked to the ball bearing. 
     
     
         20 . The orbital tensioner as in  claim 15  further comprising a removable pin engaged with the pivot arm and the base.