BLADE ROOT SPRING INSERTION JIG AND INSERTION METHOD OF BLADE ROOT SPRING

1 . A blade root spring insertion jig for inserting a blade root spring into a gap between a bottom face of a blade groove formed in a rotor disk of a rotary machine and a blade root part of a blade which engages with the blade groove, the blade root spring having a blade contact face contacting the blade root part and a rotor contact face contacting the bottom face of the blade groove, the blade root spring insertion jig comprising:

a first abutment face contacting a blade contact face side of the blade root spring; and

a second abutment face opposing the first abutment face and contacting a rotor contact face side of the blade root spring,

wherein the first abutment face and the second abutment face are configured to press the blade root spring so that the blade root spring is compressed and a height of the blade root spring becomes smaller than a natural height of the blade root spring.

2 . The blade root spring insertion jig according to claim 1 , further comprising:

a first member comprising the first abutment face;

a second member comprising the second abutment face; and

a clearance adjustment mechanism for changing a distance between the first member and the second member to adjust a clearance between the first abutment face and the second abutment face.

3 . The blade root spring insertion jig according to claim 2 ,

wherein a projection is formed on the first member to contact the blade contact face.

4 . The blade root spring insertion jig according to claim 1 ,

wherein at least one of the first abutment face or the second abutment face has a taper shape such that a distance between the first abutment face and the second abutment face gradually becomes smaller along an insertion direction of the blade root spring.

5 . The blade root spring insertion jig according to claim 1 , further comprising:

a pair of sidewall faces which forms with the first abutment face and the second abutment face a space for housing the blade root spring,

wherein the pair of sidewall faces is inclined relative to a jig end face of the blade root spring insertion jig so that the pair of sidewall faces is parallel to the blade groove when the jig end face is abutted to a disk end face of the rotor disk in a periphery of the blade groove.

6 . The blade root spring insertion jig according to claim 1 ,

wherein a clearance between the first abutment face and the second abutment face is set so that the height of the blade root spring compressed by the first abutment face and the second abutment face is greater than the gap between the bottom face of the blade groove and the blade root part.

7 . The blade root spring insertion jig according to claim 2 , further comprising

a roller provided in an abutment part of at least one of the first member or the second member, the abutment part being configured to contact the blade root spring.

8 . A blade root spring insertion method for inserting a blade root spring into a gap between a bottom face of a blade groove formed in a rotor disk of a rotary machine and a blade root part of a blade which engages with the blade groove, the method comprising steps of:

compressing the blade root spring so that a height of the blade root spring becomes smaller than a natural height of the blade root spring; and

inserting the blade root spring in the blade groove in such a state that the blade root spring is compressed.