Method for giving shroud interference to axial-entry blades in a rotary machine and rotary machine

A method for assembling a rotary member assembly, wherein the rotary member assembly comprising:

• a rotor wheel having a peripheral rim and configured to rotate around a rotation axis, wherein the rotor wheel has a plurality of circumferentially spaced female dovetail slots about the rim of the rotor wheel;
• and
• a plurality of blades configured to intercept a fluid stream while on a turbomachine,
• wherein each blade comprises a male dovetail shaped to fit with a corresponding female dovetail slot of the rotor wheel following an insertion direction,
• wherein the female dovetail slot is shaped so that the insertion direction of each male dovetail is convergent with the rotation axis of the rotor wheel to form with it an insertion convergence angle,
• wherein the method comprises the following steps:
• partially inserting the male dovetails of each blade into a respective female dovetail slot so that all the blades are at least partially inserted in the respective female dovetail slot,
• for each blade, continuing to insert each male dovetail into the respective female dovetail slot and male dovetails neighboring blades until the male dovetail of each blade is inserted completely in the respective female dovetail slot, and
• obtaining a designed airfoil shroud interference.

A steam turbine, comprising:

• a rotor wheel having an outer peripheral edge with slots equally-spaced from one another about an axis of rotation;
• and
• blades coupled to the rotor wheel, one each disposed at one of the slots, the blades comprising:
• an airfoil with a first end and a second end,
• a platform coupled to the first end and having a root that matches the shape of the slots on the rotor wheel, and
• an airfoil shroud coupled to the second end of the airfoil,
• wherein the shape of the slots on the rotor wheel are configured to orient the blades at an angle relative to the axis of rotation that converges toward the axis of rotation, and
• wherein the angle is configured to cause both sides of the airfoil shroud on adjacent blades to contact each other when the blades reside on the rotor wheel with the platform fully-inserted into the slot.