Variable stator vane and compressor

1. A variable stator vane, comprising:

a stator vane body which is configured to be disposed in a flow path through which a working fluid flows and by which a clearance is configured to be formed between the stator vane body and an inner casing;

a rotary shaft which is configured to rotate such that an angle of the stator vane body with respect to a flow direction of a main flow of the working fluid varies; and

a connection part which connects the stator vane body and the rotary shaft,

wherein the stator vane body has a first end surface located in a portion closest to a leading edge of the stator vane body and facing an outer circumferential surface of the inner casing,

wherein at least a portion of the clearance is formed between the first end surface and the outer circumferential surface of the inner casing,

wherein the connection part includes:

a first guide surface which is configured to guide a leakage flow of the working fluid which has flowed into a side closer to the portion of the clearance formed between the first end surface and the outer circumferential surface of the inner casing so that a flow direction of the leakage flow is directed to a flow direction of the main flow;

a connection part body which connects the stator vane body and the rotary shaft; and

a protruding part which is provided in the portion closest to the leading edge of the stator vane body with respect to the connection part body, protrudes from the connection part body while in contact with the first end surface, and includes the first guide surface,

wherein the protruding part includes a second guide surface disposed at a position close to a pressure surface of the stator vane body, and

wherein the first and second guide surfaces are formed such that a distance between the first guide surface and the second guide surface increases from a distal end of the protruding part toward a base end of the protruding part.

2. The variable stator vane according to claim 1 , wherein the first guide surface is disposed in a portion of the connection part which is close to the leading edge of the stator vane body and close to a suction surface side of the stator vane body.

3. The variable stator vane according to claim 1 , wherein the first guide surface is a curved surface which protrudes so as to approach a suction surface of the stator vane body.

4. The variable stator vane according to claim 1 , wherein a shape of a distal end portion of the protruding part is a rounded shape.

5. The variable stator vane according to claim 1 , wherein the protruding part is provided to cover an entirety of the first end surface closest to the leading edge of the stator vane body.

6. The variable stator vane according to claim 1 , wherein the rotary shaft includes a rotary shaft body and a diameter-enlarged part which connects the rotary shaft body and the connection part and has a diameter larger than an outer diameter of the rotary shaft body, and

the connection part has a shape in which a width of the connection part is wider from the stator vane body toward the diameter-enlarged part.

7. The variable stator vane according to claim 1 , wherein the rotary shaft includes a rotary shaft body and a diameter-enlarged part which connects the rotary shaft body and the connection part and has a diameter larger than an outer diameter of the rotary shaft body, and

the protruding part is provided to cover at least a part of the first end surface closest to the leading edge of the stator vane body and is disposed to extend toward a side surface of the diameter-enlarged part.

8. A compressor, comprising:

the variable stator vane according to claim 7 ;

a rotor which includes a rotor body and a plurality of rotor blades arranged in an axial direction and a circumferential direction of the rotor body;

the inner casing provided outside the rotor;

an outer casing provided outside the inner casing; and

a rotation driving part which is connected to the rotary shaft and is configured to rotate the rotary shaft,

wherein the inner casing includes a shaft accommodation part which has the rotary shaft accommodated therein and a chamfered part which defines a gap between the protruding part and the inner casing, and

a chamfered surface of the chamfered part is connected to a side surface of the shaft accommodation part.

9. A compressor, comprising:

the variable stator vane according to claim 1 ;

a rotor which includes a rotor body and a plurality of rotor blades arranged in an axial direction and a circumferential direction of the rotor body;

the inner casing provided outside the rotor;

an outer casing provided outside the inner casing; and

a rotation driving part which is connected to the rotary shaft and is configured to rotate the rotary shaft,

wherein the inner casing includes a shaft accommodation part which has the rotary shaft accommodated therein.

10. The compressor according to claim 9 , wherein the variable stator vane includes another rotary shaft which is connected to the stator vane body located on a side opposite from a side on which the rotary shaft is provided and rotatably supported by the outer casing.

11. A variable stator vane, comprising:

a stator vane body which is configured to be disposed in a flow path through which a working fluid flows and by which a clearance is configured to be formed between the stator vane body and an inner casing;

a rotary shaft which is configured to rotate such that an angle of the stator vane body with respect to a flow direction of a main flow of the working fluid varies; and

a connection part which connects the stator vane body and the rotary shaft,

wherein the stator vane body has a first end surface is located in a portion closest to a leading edge of the stator vane body and facing an outer circumferential surface of the inner casing,

wherein at least a portion of the clearance is formed between the first end surface and the outer circumferential surface of the inner casing,

wherein the connection part includes

a first guide surface which is configured to guide a leakage flow of the working fluid which has flowed into a side closer to the portion of clearance is formed between the first end surface and the outer circumferential surface of the inner casing so that a flow direction of the leakage flow is directed to a flow direction of the main flow;

a connection part body which connects the stator vane body and the rotary shaft; and

a protruding part which is provided in the portion closest to the leading edge of the stator vane body with respect to the connection part body, protrudes from the connection part body while in contact with the first end surface, and includes the first guide surface, and

wherein the protruding part is provided to cover an entirety of the first end surface closest to the leading edge of the stator vane body.

12. A compressor, comprising:

a variable stator vane;

a rotor which includes a rotor body and a plurality of rotor blades arranged in an axial direction and a circumferential direction of the rotor body;

an inner casing provided outside the rotor;

an outer casing provided outside the inner casing; and

a rotation driving part which is connected to a rotary shaft of variable stator vane and is configured to rotate the rotary shaft,

wherein the variable stator vane includes

a stator vane body which is configured to be disposed in a flow path through which a working fluid flows and by which a clearance is configured to be formed between the stator vane body and the inner casing;

the rotary shaft, wherein the rotary is configured to rotate such that an angle of the stator vane body with respect to a flow direction of a main flow of the working fluid varies; and

a connection part which connects the stator vane body and the rotary shaft,

wherein the stator vane body has a first end surface is located in a portion closest to a leading edge of the stator vane body and facing an outer circumferential surface of the inner casing,

wherein at least a portion of the clearance is formed between the first end surface and the outer circumferential surface of the inner casing,

wherein the connection part includes

a first guide surface which is configured to guide a leakage flow of the working fluid which has flowed into a side closer to the portion of clearance is formed between the first end surface and the outer circumferential surface of the inner casing-so that a flow direction of the leakage flow is directed to a flow direction of the main flow;

a connection part body which connects the stator vane body and the rotary shaft; and

a protruding part which is provided in the portion closest to the leading edge of the stator vane body with respect to the connection part body, protrudes from the connection part body while in contact with the first end surface, and includes the first guide surface,

wherein the rotary shaft includes a rotary shaft body and a diameter-enlarged part which connects the rotary shaft body and the connection part and has a diameter larger than an outer diameter of the rotary shaft body,

wherein the protruding part is provided to cover at least a part of the first end surface closest to the leading edge of the stator vane body and is disposed to extend toward a side surface of the diameter-enlarged part,

wherein the inner casing includes a shaft accommodation part which has the rotary shaft accommodated therein and a chamfered part which defines a gap between the protruding part and the inner casing, and

wherein a chamfered surface of the chamfered part is connected to a side surface of the shaft accommodation part.