Modular unit comprising a bush for chain drives

Abstract

A modular assembly is provided having a metal bushing ( 1 ), which is inserted into a plastic support body ( 3 ) for a tensioning rail or a guiding rail ( 4 ) of a chain drive of an internal combustion engine which axially contacts the motor housing ( 5 ), and is mounted via a screw extending through the bushing ( 1 ). The bushing ( 1 ) according to the invention is provided as a rotationally symmetrical body and is inserted into a bore hole of the support body ( 3 ), the bushing is provided at its end section, facing the motor, with a circular step ( 10 ) for a transition to a reduced exterior diameter, by which it is axially supported on a step ( 11 ) provided with a reduced interior diameter inside the mounting hole of the support body ( 3 ).

1 . An assembly comprising a metal bushing ( 1 ) which is inserted into a plastic supporting body ( 3 ) for a tensioning rail ( 4 ) or a guiding rail ( 4 ) of a chain drive of an internal combustion engine and being mounted by a screw extending through the bushing ( 1 ) to and axially contacting a motor housing ( 5 ), the bushing ( 1 ) comprises a rotationally symmetrical body and is inserted into a mounting hole of the supporting body ( 3 ) with an end section facing the motor being provided with a circular step ( 10 ) for a transition to a reduced exterior diameter, by which the bushing is axially held to a step ( 11 ) provided with a reduced interior diameter, located inside the mounting hole of the supporting body ( 3 ).  
   
   
       2 . An assembly according to  claim 1 , wherein the support body ( 3 ) with the mounting hole is surrounded by the guiding rail or tensioning rail ( 4 ) formed from plastic.  
   
   
       3 . An assembly according to  claim 1 , wherein the bushing ( 1 ), is used at a tensioning rail ( 4 ), and inside the mounting hole a gap ( 12 ) is provided to allow pivoting of the support body ( 3 ) around a bushing axis.  
   
   
       4 . An assembly according to  claim 1 , wherein the mounting hole of the support body ( 3 ) is a reference bore ( 6 ) or a primary mounting hole.  
   
   
       5 . An assembly according to  claim 4 , wherein a secondary mounting hole is provided and is formed as an oblong hole ( 7 ) in the supporting body ( 3 ) in addition to the reference bore ( 6 ).  
   
   
       6 . An assembly according to  claim 5 , wherein a bead ( 14 ) is located on a wall region of the reference bore ( 6 ) and/or of the oblong bore ( 7 ), and is received in a circular groove ( 13 ) of the inserted bushing ( 1 ).