| 主权项 |
1. A variable nozzle unit configured to adjust a passage area for an exhaust gas to be supplied to a turbine impeller in a variable geometry system turbocharger, comprising:
a base ring arranged coaxial with the turbine impeller in a turbine housing in the variable geometry system turbocharger, and including a plurality of support holes penetratingly formed at intervals in a circumferential direction of the base ring; a plurality of variable nozzles arranged on the base ring at intervals, each variable nozzle being rotatable around its axis in parallel with an axis of the turbine impeller and being integrally provided with a nozzle shaft on a lateral surface thereof, the nozzle shaft being rotatably supported by the corresponding support hole in the base ring; and a link mechanism arranged on one side of the base ring and configured to synchronously rotate the plurality of variable nozzles in forward and reverse directions, wherein the link mechanism comprises: three or more, attachment pins arranged on a lateral surface of the base ring on the one side at intervals in the circumferential direction of the base ring, the attachment pins placed outside the support holes in the base ring in radial directions of the base ring; a guide ring provided across the plurality of attachment pins and placed coaxial with the base ring; a drive ring being rotatably provided on an outer peripheral surface of the guide ring, including as many engagement portions as the variable nozzles provided on a lateral surface of the drive ring at intervals in a circumferential direction of the drive ring, and being configured to rotate in forward and reverse directions by being driven by an rotary actuator; a first side guide member provided on one side of the guide ring and configured to support a lateral surface of the drive ring on the one side in a way that allows the lateral surface to be in sliding contact with the first side guide member; a second side guide member provided on an opposite side of the guide ring and configured to support a lateral surface of the drive ring on the opposite side in a way that allows the lateral surface to be in sliding contact with the second side guide member; and a synchronous link member including
a base end portion integrally connected to the nozzle shaft of each variable nozzle, andtip end portions engaged with each engagement portion of the drive ring while nipping the engagement portion. |
