Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
  • F01D5/32—Locking, e.g. by final locking blades or keys
  • F01D5/323—Locking of axial insertion type blades by means of a key or the like parallel to the axis of the rotor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
  • F01D5/3007—Fixing blades to rotors; Blade roots ; Blade spacers of axial insertion type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
  • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
  • F01D5/30—Fixing blades to rotors; Blade roots ; Blade spacers
  • F01D5/3007—Fixing blades to rotors; Blade roots ; Blade spacers of axial insertion type
  • F01D5/3015—Fixing blades to rotors; Blade roots ; Blade spacers of axial insertion type with side plates

Definitions

• the invention relates to an axial securing system for rotor blades of axially flowing turbomachinery according to the preamble of claim 1 and a securing body for the securing system according to the preamble of claim 8.
• securing bodies arranged in the radial gap between the blade root end and the axial groove base are generally used today.
• fuse bodies that only extend from the downstream end over part of the radially arranged axial groove, as is known, for example, from US Pat. No. 2,641,443.
• These securing bodies generally have an upstream projection which engages in an associated groove in the blade root.
• the downstream end area overhangs the Axial groove and is bent to axially secure the blade so that it engages behind the downstream rear of the blade carrier.
• a projection on the blade root engages behind the pressure side of the blade carrier at the opposite end of the blade root.
• securing bodies used for the axial securing extend over the entire length of the axial groove and protrude beyond it on both sides. This is described for example in US-2,928,651 and GB-A-643,1914.
• a projecting end region is designed as a shoulder-like projection which extends past the pressure side of the blade carrier, while the other projecting end region is brought into a position in the installed state by bending over, in which position it is engages downstream end of the blade carrier.
• 2,928,651 consists of a sheet metal, the two projecting end regions of which are designed by bending so that they engage behind the two end faces of the blade carrier in the installed state.
• the axial support connection to the blade root is produced by projections or tongues which protrude from the respective securing bodies and engage in corresponding grooves in the blade roots.
• the manufacture of the securing bodies described is complex because, on the one hand, the material must be selected so that it can be bent into the required shape but can still absorb the forces that occur. On the other hand, because the end areas of the sheets have to be bent with high precision in order to fix the blades in their axial position exactly.
• Such a securing body can only be designed to a limited extent for the possible shear and shear forces, with additional bending of the material being introduced by the bending. At the very high speeds that are used today, the bent ends do not always withstand the load and be bent up by the high forces. The blades slide axially out of their position and rub against the housing.
• the securing system for each rotor blade has a radially arranged axial groove in the blade carrier, into which the rotor blade with its blade root of opposite design can be inserted.
• a securing body is arranged between the blade root end and the axial groove base, with its first end region lying opposite the axial force acting on it
• a securing element which is formed in one piece with the blade carrier, is arranged axially adjacent to the first end region of the securing body and forms an axial stop for the latter.
• the first end region of the securing body comes to lie in a circumferential groove between the stop and the blade carrier. The attack prevents
• the securing body 20 of the securing body can be axially displaced from its position or the end region can be bent open by the forces which occur, as a result of which the blade root and with it the moving blade are held in their exact position. Due to the one-piece design of the securing element with the blade carrier, manufacture and assembly are particularly simple and inexpensive. The easiest way to manufacture the securing element, which is formed in one piece with the blade carrier, is by means of turning and / or milling; with high-quality material by grinding.
• the force acting on the end region is distributed over a larger area. This leads to a more favorable ratio of force per area also with respect to the stop formed by the securing element and assigned to the end region.
• the end regions of the securing body are wider than the base part and also wider than the axial groove, it is very advantageous if the end regions of the securing body protrude radially outward from the base part in the installed state and engage behind the end faces of the blade root and the end faces of the blade carrier. If this is the case, there is no need for an additional tongue or a projection which engages in a suitable groove in the blade root in order to establish the connection between the blade root and the securing body. This simplifies both the manufacture of the blade root and that of the securing body.
• Such a fuse body according to the invention can of course not only be used in connection with the security system according to the invention, but also instead of known fuse bodies without the fuse element. If the securing element is manufactured as a separate securing disk or as a securing ring, which is then welded or glued to a body integral with the blade carrier, then existing turbomachinery can be retrofitted with the securing system.
• 1 shows a safety system according to the invention using part of a blade carrier with a moving blade attached to the blade carrier, in perspective and in section along an axial groove bottom of the blade carrier; 2 shows in perspective an inventive fuse body of the security system;
• FIG. 3 also shows a security system according to the invention in a representation analogous to FIG. 1;
• FIG. 4 shows the embodiment from FIG. 3 in another perspective view without a rotor blade
• FIGS. 1 and 3 each show a rotor blade 10 which is fastened with its 12 in a radially arranged axial groove 14 of a blade carrier 16.
• the blade root 12 is designed as a fir tree root and the axial groove 14 as an opposite groove, so that the blade root 12 is anchored radially and in the circumferential direction in the groove 14 so that it cannot move.
• a securing body 22 is arranged between a blade root end 13 belonging to the blade root 12 and an axial groove bottom 15 which delimits the axial groove 14 radially inward, the two end regions 26, 26 'of which protrude axially beyond the axial groove 14.
• the two end regions 26, 26 ' are each wider than a base part 28 of the securing body 22 connecting them.
• the end regions 26, 26' each protrude radially outward from the base part 28 and each engage behind one end face 38 ", 40 'of the blade root 12 and part of the end faces 38, 40 of the blade carrier 16.
• the end regions 26, 26' of the securing body 22 are wider than the base part 28 and wider than the axial grooves 14, they also engage behind Parts of the end faces 38, 40 of the blade carrier 16 when they protrude radially outward from the base part 28.
• the first end face 38 of the blade carrier 16 forms the pressure side of the blade carrier 16. A very large axial force acts on this side due to the direction of flow A (see arrow). Via the blade root 12, this axially acting force is also transmitted to the first end region 26 of the securing body 22, which engages behind the opposite end face 40 of the blade carrier - also called the rear side 40.
• a securing element 24 is arranged on the rear side 40 of the blade carrier 16 and forms a stop 34 for the first end region 26 downstream in the axial direction, so that the first end region 26 can no longer be bent open.
• the securing element 24 forms, together with the securing body 22, the axial groove 14 and the blade root 12, a securing system 20 which connects the moving blade 10 to the blade carrier 16 in a positionally secure manner even at very high speeds in the axial, radial and circumferential directions.
• the securing body 22 is formed from sheet metal and both end regions 26, 26 'are brought to the base part 28 by bending radially outward into their position.
• the first end region 38 which engages behind the rear side 40 of the blade carrier, can also be designed as a solid projection and only the second end region 26 'can be brought into position by bending.
• Figures 3 and 4 show the securing element 24 integrally formed with the blade carrier 16.
• the axial grooves 14 are first milled or cleared into the base body of the blade carrier 16. Then, on the rear side 40 of the blade carrier 16, a strip measuring approximately twice the thickness of the securing body 22 is twisted, radially inwards to such an extent that the stationary shoulder projects radially outwards beyond the axial groove base 15 somewhat more than the first, which protrudes radially outwards End region 26 of the securing body 22.
• a circumferential groove 42 is created by turning, which extends radially inward somewhat beyond the axial groove bottom 15 and whose width is dimensioned such that it is the first with little play End portion 26 of the fuse body 22 can accommodate.
• the circumferential groove 42 can also be formed by grinding.
• each blade root 12 and the base part 28 of each securing body 22 corresponds to the axial extension of the axial grooves 14 which have remained after turning, so that after installation no blade root 12 and no part of a base part 28 protrude into the circumferential groove 42 or over the pressure side 38 of the Blade carrier protrudes.
• the securing element 24 can be combined with arbitrarily designed securing bodies and then forms a securing system 20 according to the invention. Corresponding adaptations of the circumferential groove 42 do not pose a problem.
• the securing element 24 can also be designed as a separate securing washer 32 which, for example, is connected to the blade carrier 16 by means of a welded connection 30 to form an integral body.
• the locking washer 32 has on its side facing the blade carrier 16 a shoulder which is designed such that when connected to the blade carrier 16 there is a circumferential groove 42 in which the respective first end regions 26 of the locking bodies 22 for the rotor blades 10 engage.
• the securing element 24 can also be designed as a securing ring. Instead of using a welded connection 30, it is also conceivable to connect the securing element 24 to the blade carrier 16 by means of an adhesive connection to form an integral body.
• An advantage of the separate configuration of the securing element 24 is that existing blade carriers 16 with axial groove / securing body connections can be retrofitted with this securing element 24 and connected to the securing element to form one-piece bodies. In this way, a security system according to the invention can be installed subsequently. This is possible regardless of the design of the fuse body. This is because the security system 20 also works with other security bodies, as are known, for example, from the patents mentioned at the beginning. For this purpose, the securing element 24 may then have to be adapted in accordance with the configuration of the circumferential groove 42 or the stop 34.
• the securing body 22 is first inserted into the axial groove 14, specifically in such a way that the first end region 26, which is already radially from the base protrudes steeply 28, is received by the circumferential groove 42.
• the first end region 26 is then inserted with little play between the stop 34 of the securing element 32 and the corresponding parts of the end face 40 of the blade carrier 16.
• the moving blade with its blade root 14 is then inserted from the pressure side 38 over the securing body 22 into the axial groove 14 of the blade carrier 16 inserted.
• the second end region 26 'of the securing body 22 is bent radially outward, so that the blade root 12 is axially fixed with the aid of the two end regions 26, 26'.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

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ID=4563621

Family Applications (1)

Country Status (6)

Cited By (3)

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Citations (9)

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• 2002
  • 2002-06-25 EP EP02737718A patent/EP1402152B1/de not_active Expired - Lifetime
  • 2002-06-25 JP JP2003510577A patent/JP4315801B2/ja not_active Expired - Lifetime
  • 2002-06-25 WO PCT/CH2002/000344 patent/WO2003004834A1/de active IP Right Grant
  • 2002-06-25 DE DE50209295T patent/DE50209295D1/de not_active Expired - Lifetime
  • 2002-06-25 KR KR1020037017202A patent/KR100837134B1/ko active IP Right Grant
  • 2002-06-25 CN CNB028134389A patent/CN100416045C/zh not_active Expired - Lifetime

Patent Citations (9)

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