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US 5,203,676 AGranted
Ruggedized tapered twisted integral shroud blade
AssigneeWestinghouse Electric Corp.
InventorsJurek Ferleger, Shun Chen
Life of this patent
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Abstract
A tapered twisted rotating blade for the fourth rotating blade row of a BB71 and BB471 turbine has a shroud segment integrally formed on the tip of the airfoil portion such that the shroud is dimensionalized according to materials used so that the tuned frequencies remain the same regardless of materials used, based on changes in Young's modulus due to use of different materials. The blade also has a pitch to chord ratio that increases linearly with length of the blade.
Claims5
A tapered twisted rotating blade comprising:
- a straight side-entry root portion;
- a platform portion;
- an airfoil portion integrally formed with the platform and root portions and having a base section disposed at the platform portion, thus constituting a proximal;
- end of the airfoil portion, and a tip section constituting an opposite, distal end of the airfoil portion, and a shroud segment integrally formed on the airfoil portion at the tip section, the airfoil portion of the blade being divided into five basic sections including the base section and the tip section, a quarter section, a mean section and a three quarter section, and the blade in each section defining a pitch and a chord with a pitch to chord ratio that increases linearly with length of the blade.
1 more element
Blading for a BB71, or BB471 turbine according to the following table:
- ______________________________________ THREE QUAR- QUAR- BASE TER HALF TER TIP ______________________________________ RADIUS (IN) 26.707 28.500 30.313 32.000 33.914 WIDTH (IN) 1.757 1.610 1.449 1.288 1.137 CHORD (IN) 2.432 2.396 2.358 2.338 2.328 PITCH/WIDTH .900 1.048 1.239 1.471 1.768 PITCH/CHORD .650 .704 .761 .811 .863 STAGGER 42.496 45.920 51.583 56.353 60.911 ANGLE (DEG) MAXIMUM .713 .571 .430 .303 .228 THICKNESS (IN) MAX. THICK- .293 .238 .182 .129 .098 NESS/CHORD TURNING 103.000 91.239 75.126 51.114 46.590 ANGLE (DEG) EXIT OPEN- .437 .487 .540 .590 .649 ING (IN) EXIT OPEN- 24.698 26.165 28.383 31.454 31.597 ING ANGLE INLET METAL 59.715 71.347 87.298 101.509 115.101 ANGLE INLET INCL. 82.389 74.336 57.438 43.312 39.916 ANGLE EXIT METAL 17.283 17.413 17.575 17.375 18.308 ANGLE (DEG) EXIT INCL. 4.619 5.696 5.697 6.853 6.349 ANGLE (DEG) SUCTION 9.723 11.601 13.658 17.505 15.464 SURFACE TURNING AREA (IN**2) .993 .782 .583 .436 .340 ALPHA (DEG) 44.115 48.577 53.332 58.035 62.774 FX (IN**(1-4)) 13.494 27.966 65.818 170.108 468.529 FY (IN**(1-4)) 14.143 22.741 39.118 70.569 130.904 FXY (IN**(1-4)) 10.500 20.809 44.596 101.278 236.231 I TOR (IN**4) .080 .043 .019 .007 .003 I MIN (IN**4) .041 .021 .010 .004 .001 I MAX (IN**4) .301 .228 .169 .133 .106 X BAR .019 .002 -.013 -.020 -.012 Y BAR .017 .019 .012 .007 .010 ZMINLE -.077 -.049 -.028 -.015 -008 (IN**3) ZMAXLE .386 .295 .209 .154 .116 (IN**3) ZMINTE -.090 -.059 -.035 -.020 -.013 (IN**3) ZMAXTE -.785 -.140 -.109 -.091 -.076 (IN**3) CMINLE -.532 -.439 -.356 -.276 -.203 (IN**3) CMAXLE .781 .773 .807 .863 .913 (IN**3) CMINTE -.453 -.365 -.281 -.207 -.128 (IN**3) CMAXTE -1.690 -1.621 -1.536 -1.462 -1.398 (IN**3) ______________________________________
Dependencies are inferred from the claim text.