摘要 |
The present invention relates to a hydraulic auto-tensioner, in particular for a chain drive of an internal combustion engine, comprising a housing, a tensioning plunger guided in a plunger bore of said housing, a free piston guided in said plunger bore, and a plunger rod formed on said tensioning plunger and extending through the free piston. The tensioning plunger, the housing and the free piston delimit a hydraulic reservoir which is sealed with respect to the housing and the plunger rod by means of a sealing unit that is arranged on the free piston. The sealing unit is implemented as a double seal ring with an outer sealing surface which is in sliding contact with the plunger bore of the housing, and an inner sealing surface which is in sliding contact with the plunger rod of the tensioning plunger. In addition, the present invention relates to the use of such a double seal ring in a hydraulic auto-tensioner.
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