Abstract: A chain tensioner is provided which is configured such that the air remaining in a pressure chamber can be discharged to the outside through a helical gap defined between a screw and a threaded hole, and through between circumferentially separate radial ends of a spring washer mounted between the screw and a housing. The chain tensioner includes an air discharge groove or grooves formed in the seat surface of the head of the screw such that an annular space defined between the neck of the screw and the inner diameter surface of the spring washer communicates with the outside through the air discharge groove or grooves. Even if foreign objects clog the space between the separate radial ends so as to hinder air from being discharged through between the separate radial ends, the air remaining in the pressure chamber can be discharged to the outside through the air discharge groove or grooves.

Abstract: A system for emergency lubrication, with a lubricant pump (113) and with at least one outlet opening (125) for delivering lubricant to at least a first lubrication point (107) of a transmission (101), in particular a transmission of a wind turbine. The system includes a first cavity (203), and the lubricant pump (113) is designed to convey at least some of the lubricant into the first cavity (203). The first cavity (203) is designed to store the lubricant intermediately and to act upon the intermediately stored lubricant with positional energy. In addition, there is a lubricant-conveying connection between the first cavity (203) and the outlet opening (125).