Eccentric tensioning device

Abstract

An eccentric tensioning device for tensioning the traction means of a traction means drive is provided. The invention provides solutions, through which advantages are given in the installation of tensioning devices under assembly-specific aspects. The eccentric tensioning device for a traction means drive includes a track roller device, which has a running disk and a rolling bearing provided for supporting this disk, a work eccentric for supporting the track roller device such that it can be displaced in a radial direction relative to the rotating axis of the rolling bearing through pivoting of the work eccentric, a torsion spring for pretensioning the work eccentric, and a fixing device for securing the work eccentric in a mounting position, in which the torsion spring is located in pretensioned state. The fixing device is constructed such that it can be brought into a released state during attachment of the eccentric tensioning device to a flange surface, in which the running disk is forced radially relative to the rotating axis of the rolling bearing against the associated traction means due to the work eccentric. Therefore, it is possible in an advantageous way to create a tensioning device, in which during the mounting of the traction means, the work or the operating eccentric is fixed in an end position and an activation of the tensioning device is guaranteed in a reliable way.

1 . Eccentric tensioning device for a traction means drive, comprising:
 a track roller device, which as such comprises a running disk and a rolling bearing provided for supporting the running disk,   a work eccentric for supporting the track roller device, such that it can be displaced in a radial direction relative to a rotating axis of the rolling bearing according to a magnitude of pivoting of the work eccentric,   a torsion spring for pretensioning the work eccentric, and   a fixing device for securing the work eccentric in a mounting position, in which the torsion spring is located in a pretensioned state,   the fixing device is positionable on a flange surface upon which the eccentric tensioning device is mountable during attachment of the eccentric tensioning device, in which the running disk is forced radially relative to the rotating axis of the rolling bearing against the associated traction means under effect of the work eccentric.   
   
   
       2 . Eccentric tensioning device according to  claim 1 , wherein the fixing device is automatically detachable through tightening of an attachment screw with which the eccentric tensioning device is connected to the flange surface carrying the eccentric tensioning device. 
   
   
       3 . Eccentric tensioning device according to  claim 2 , wherein a free switching path is traversed, through an axial play being overcome, during attachment of the eccentric tensioning device to the flange surface using the attachment screw. 
   
   
       4 . Eccentric tensioning device according to  claim 3 , wherein the axial play (S) is overcome against an axial force applied by the torsion spring. 
   
   
       5 . Eccentric tensioning device according to  claim 3 , wherein an engagement structure connected to the work eccentric is moved to a released state during the course of overcoming the axial play. 
   
   
       6 . Eccentric tensioning device according to  claim 5 , wherein the engagement structure is attached to the work eccentric via an indexer arm. 
   
   
       7 . Eccentric tensioning device according to  claim 6 , wherein in the mounting position the engagement structure engages with a holding element that is provided by a base plate. 
   
   
       8 . Eccentric tensioning device according to  claim 7 , wherein the engagement structure is brought into a released state through axial displacement of the engagement structure relative to the holding element. 
   
   
       9 . Eccentric tensioning device according to  claim 7 , wherein the engagement structure is brought into a released state through radial displacement of the engagement structure relative to the holding element. 
   
   
       10 . Eccentric tensioning device according to  claim 9 , wherein the torsion spring is constructed as a helical spring. 
   
   
       11 . Eccentric tensioning device according to  claim 1 , wherein a damping device is provided for generating an eccentric braking moment counteracting a radial displacement of the track roller device. 
   
   
       12 . Eccentric tensioning device according to  claim 1 , wherein the work eccentric comprises a plastic material. 
   
   
       13 . Eccentric tensioning device according to  claim 1 , wherein the work eccentric is constructed in one piece with an inner ring of the rolling bearing. 
   
   
       14 . Eccentric tensioning device according to  claim 1 , wherein the running disk is constructed in one piece with an outer ring of the rolling bearing. 
   
   
       15 . Eccentric tensioning device according to  claim 1 , wherein the work eccentric is supported on an adjustment eccentric. 
   
   
       16 . Eccentric tensioning device according to  claim 15 , wherein the adjustment eccentric is axially displaceable and a released state can be reached through axial displacement of the adjustment eccentric by the attachment screw. 
   
   
       17 . Eccentric tensioning device according to  claim 1 , further comprising a base plate having an annular disk section for clamping onto the flange surface, and the annular disk section is coupled locked in rotation with a carrier body in an area of an inner peripheral edge, and a holding element is formed on the base plate in an outer edge region of the base plate. 
   
   
       18 . Eccentric tensioning device according to  claim 17 , wherein a projection is formed on the base plate for rotationally locked anchoring of the base plate on the flange surface. 
   
   
       19 . Eccentric tensioning device according to  claim 18 , wherein the projection is constructed so that the rotationally locked anchoring of the base plate on the flange surface is achieved before an axial release path is overcome. 
   
   
       20 . Eccentric tensioning device according to  claim 19 , wherein the released state is attained by pivoting the work eccentric back against a pivoting direction caused by the torsion spring. 
   
   
       21 . Eccentric tensioning device according to  claim 20 , wherein the released state is attained by an overload moment also introduced into the work eccentric and acting in a direction of the tensioning moment generated by the torsion spring. 
   
   
       22 . Eccentric tensioning device according to  claim 1 , wherein securing means are provided, which prevent re-engagement of the fixing device. 
   
   
       23 . Method for integrating an eccentric tensioning device into a traction means drive of an internal combustion engine, comprising: within the scope of a preparation mounting step, partially attaching an eccentric tensioning device located in a pretensioned state to a flange surface, such that the eccentric tensioning device remains in the pretensioned state, wherein in the pretensioned state, the eccentric tensioning device is configured such that a track roller of the device has a large distance from a traction means running path, and bringing the eccentric tensioning device into a released state through tightening of an attachment screw used for fastening the eccentric tensioning device in position, releasing the pretensioned state and moving the track roller onto an associated traction means of the traction means drive.