Turbine rotor blade and rotary machine

1. A turbine rotor blade comprising:

a plurality of blade bodies which are mounted so as to extend in a radial direction from a rotor body rotatable about an axis in a casing, the plurality of blade bodies being disposed at intervals in a circumferential direction of the rotor body; and

an annular tip shroud connected to each tip end part of the plurality of blade bodies,

wherein the tip shroud includes at least one first through hole, and the at least one first through hole penetrates the tip shroud in the radial direction so as to bring a first cavity and an inter-blade flow passage into communication,

wherein

the first cavity is defined between a first seal fin and a second seal fin,

the first seal fin extends in the radial direction from one of an outer peripheral surface of the tip shroud or an inner peripheral surface of the casing toward the other of the outer peripheral surface or the inner peripheral surface, and has a tip part,

the first seal fin forms a gap between the tip part and the other of the outer peripheral surface or the inner peripheral surface,

the second seal fin extends in the radial direction from one of the outer peripheral surface of the tip shroud or the inner peripheral surface of the casing toward the other of the outer peripheral surface or the inner peripheral surface at a position spaced apart from the first seal fin in a direction of the axis, and has a tip part,

the second seal fin forms a gap between the tip part and the other of the outer peripheral surface or the inner peripheral surface,

the inter-blade flow passage is formed between a pair of adjacent blade bodies in the circumferential direction of the rotor body,

the at least one first through hole includes a first opening opened on a side of the first cavity and a second opening opened on a side of the inter-blade flow passage,

the first opening is formed at an intermediate position between the first seal fin and the second seal fin, and

the second opening is formed at a position facing the inter-blade flow passage, the position of the second opening having the same static pressure as a static pressure at the intermediate position facing the first opening.

2. The turbine rotor blade according to claim 1 ,

wherein the at least one first through hole includes the first opening opened on the side of the first cavity and a first-cavity-side flow passage portion connected to the first opening, and

wherein the first-cavity-side flow passage portion is oriented to an upstream side of a rotational direction of the rotor body in the first cavity.

3. The turbine rotor blade according to claim 1 ,

wherein the at least one first through hole includes the second opening opened on the side of the inter-blade flow passage and an inter-blade-side flow passage portion connected to the second opening, and

wherein the inter-blade-side flow passage portion is oriented to a downstream side of the inter-blade flow passage.

4. The turbine rotor blade according to claim 1 ,

wherein the at least one first through hole includes a plurality of first through holes having the same diameter, and

wherein the plurality of first through holes are formed at regular intervals along the circumferential direction over an entire periphery of the annular tip shroud.

5. The turbine rotor blade according to claim 1 ,

wherein

the tip shroud includes at least one second through hole, and the second through hole penetrates the tip shroud in the radial direction so as to bring a second cavity and the inter-blade flow passage into communication,

wherein

the second cavity is defined between the second seal fin and a third seal fin,

the third seal fin extends in the radial direction from one of the outer peripheral surface of the tip shroud or the inner peripheral surface of the casing toward the other of the outer peripheral surface or the inner peripheral surface at a position spaced apart from the second seal fin in the direction of the axis from the first seal fin toward the second seal fin, and has a tip part, and

the third seal fin forms a gap between the tip part and the other of the outer peripheral surface or the inner peripheral surface.

6. A rotary machine comprising:

the turbine rotor blade according to claim 1 ; and the casing.