US Patent 10125673 Variable nozzle unit and variable geometry turbocharger

In a variable nozzle unit, at a position located away from and opposed to a first nozzle ring in a right-left direction, a second nozzle ring is provided integrally with the first nozzle ring through multiple connecting pins arranged in a circumferential direction. An inner edge portion of a support ring is connected to the first nozzle ring by riveting of one end portions of the multiple connecting pins. Each pin hole in the support ring is formed into such a shape extending in a radial direction of the support ring. A washer is provided between a rim of each pin hole in the support ring and a rivet head brought about by joining of the end portion of the corresponding connecting pin.