The invention concerns a method of securing stator blades in a blade ring. Background Arts

Blades in a blade ring must be fixed after insertion in place. At present there are two most common methods of this fixation.

The first is based on the fact that the blade ring material is about 10% thicker than the required final thickness of the blade ring body. The reinforced circular material is used for turning a ring of square profile (securing ring). A groove is turned in the rest of the blade ring reaching as far as the bodies of the inserted blades. The turned square profile is inserted in the groove to fix the blades (fig. 2). Disadvantages of this method include the fact that the securing ring is made of the blade ring body, which result in plenty of waste. In addition this process is time-consuming and technology intensive, which makes the fixation of the blades in the blade ring body more expensive.

The second known method (fig. 3) is fixation of the blades in the blade ring with a lock pin. In this case each blade must be co-drilled with the blade for the lock pin to be inserted in the matching ring and blade holes. This method is also time-consuming and the individual steps are demanding for the worker.

Disclosure of Invention

The method of fixation of a blade in a blade ring with a securing wire pursuant to this invention comprises a groove milled in the blade body during its manufacture and corresponding to the diameter of the circular profile of the securing wire. Then a groove is turned in the blade ring body corresponding to the diameter of the securing wire, starting openings are drilled and blade profiles are cut in the blade ring, then the blades with the turned grooves are inserted in the blade ring and finally the securing wire is placed in position (fig. 1).

The advantages of the solution pursuant to this invention above all include the fact that the blade ring need not be clamped and turned again, being completely finished after the first operation, and that the securing wire is common consumer goods with minimum manufacturing costs. This represents a big economic asset consisting in material and time saving while turning the blade ring.

Brief Description of Drawings

The technical solution will be explained in detail with the help of a drawing where fig. 1 shows fixation of the blades with the securing wire using this method, fig. 2 shows blade securing with a securing ring made of the blade ring body, and fig. 3 shows blade securing in the blade ring with lock pins.

Made for Carrying out the Invention

The method of securing a blade in a blade ring with a securing wire is implemented as follows: When a blade 1 is made a groove is milled in the blade body 1 corresponding to the diameter of the circular profile of the securing wire 3, then a groove is turned in the blade ring 2 with the diameter corresponding to the securing wire diameter 3, then starting openings are drilled and blade profiles I are cut in the blade ring 2, then the blades 2 with the milled grooves are inserted in the ring and finally the securing wire 3 is placed in position resulting from winding a bar with circular profile into the circle shape.

The body of the blade ring 2 is about 10% thinner, therefore the thickness of the material for the blade ring manufacture 2 corresponds to the final thickness of the ring 2. A groove is turned into this body with the inner diameter corresponding to the diameter of the circular profile of the securing wire 3. The blades are then fixed by pushing this securing wire 3 into the groove passing both the blade body I and the blade ring body 2. Manufacture of the securing wire 3 comprises winding the wire and not cutting the wire from the material for the blade ring manufacture.

Industrial Applicability

The invention may be used for fixation of all types of turbine and compressor stator blades to prevent their move.