bush 42 cannot slide off axially from the tensioner arm shaft 32 fig1 shows a cross section of the tensioning device of fig9 however without the screw 48 for illustration of the tensioner arm fixed support 46 the angled end of the helical torsion spring 45 engages in an opening 50 of the support flange 33 and is supported circumferentially therein the helical torsion spring 45 has a winding 51 secured to this end and bearing spotwise on the tensioner arm shaft 32 at two points of contacts which are acted upon by support forces f s to form a pair of forces when configuring the stationary support for the helical torsion spring 14 in analogous manner it is evident that the torsion of the helical torsion spring 45 does not generate a radial force that acts on the sliding bearing the attachment of the helical torsion spring 45 on the supports as illustrated with reference to the embodiments according to fig9 and 10 is certainly applicable in the same advantageous manner for the other embodiments subsequently the mode of operation of the tensioning device according to the invention is described the disposition of the helical torsion spring 14 45 in accordance with the present invention effects that the axial pressure force f d is introduced into the sliding bearing 3 36 as a reaction force f r which acts perpendicular to the sliding surfaces 7 12 43 44 the resulting increased friction dampens in advantageous manner swinging motions of the tensioner arm 1 35 the.