Variable-nozzle mechanism, exhaust turbocharger equipped therewith, and method of manufacturing exhaust turbocharger with the variable-nozzle mechanism

摘要

An exhaust turbocharger with a variable-nozzle mechanism with fail-safe feature included is provided with which, even if wear of the drive ring supporting part where the supporting elements are in reciprocating sliding or rolling contact with each other under high temperature without lubrication increases, the drive ring can be supported on the nozzle mount on the second supporting part, which enables the drive ring to be always supported rightly on the nozzle mount, and to prevent the occurrence of eccentric rotation or dropping out of the drive ring due to excessive wear of the drive ring supporting part or the occurrence of reduction in engine performance due to malfunctions of the variable-nozzle mechanism such as the error in the relation between the output of the actuator and the nozzle vane opening or the occurrence of breakage of the variable-nozzle mechanism as has been experienced in prior arts.