| 摘要 |
A tensioning device for a belt or chain drive with a tensioning lever (2) which is provided with a rotatable tension roller (6) mounted rotatably a drag bearing (3) constructed as a plain bearing on a base housing (4), and radially at a distance from the axis of rotation (5) of the drag bearing (3); with a pretensioned torsion spring (11), which is constructed as a helical spring (12, 12′), disposed coaxially with the drag bearing (3) and connected at the spring ends (13, 14) thereof at the housing side to the base housing (4), and at the lever side to the tensioning lever (2); and with a brakeshoe (16, 16′ 29) which is disposed at one spring end (13, 14) and which can be pressed by the spring end against a component which can rotate about the axis of rotation (5) of the drag bearing (3) relative to the spring end (13, 14). In order to achieve good heat dissipation of the friction damping device and uniform stress on the drag bearing (3), the brake shoe (16, 16′) is constructed and is disposed at the lever-side spring end (13) of the helical spring (12, 12′) such that the brake shoe (16, 16′) is clamped peripherally between the spring end (13) and a radially directed stop surface (23, 23′) of a catch attached to the tensioning lever (22, 22′) and, via a contacting force (FS—R) resulting from the two peripheral tangential forces (FF—T, FF—T) from the helical spring (12, 12′) and on the helical spring (12, 12′), can be pressed with an outer cylindrical friction surface (17) largely radially against a cylindrical inner wall (19) of the base housing (4).
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