Patent ID: 11905848
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  B | IPC B  F

Claim 0:
1. A turbine blade comprising a plurality of cooling passages provided along a blade height direction that are disposed at intervals in a front and rear direction of the blade, wherein
the cooling passage includes:
a first cooling pass that includes
a first cooling hole that has a first end opening toward a front end of the turbine blade, and that has an inner diameter that is constant along the blade height direction, and
a second cooling hole that has a first end communicating with a second end of the first cooling hole, and that has an inner diameter that is increased by a first expansion ratio toward a base end of the turbine blade; and

a second cooling passage that includes a cooling hole having an inner diameter that is increased by a second expansion ratio from the front end toward the base end, the second expansion ratio being smaller than the first expansion ratio,
wherein a length from the one end of the first cooling hole to a position where the first cooling hole and the second cooling hole are communicated with is 40% to 60% of a length from the first end of the first cooling hole to a gas path surface on the base end.