FR2484530A1 - BLOCKING AGAINST THE AXIAL SHIFTING OF THE PINS IN THE BOREHOLE OF THE SPACERS FOR FASTENING MOBILE FINS WITH A BREAK OF AXIAL STEAM TURBINES - Google Patents

Abstract

THE PURPOSE IS TO CREATE A CONNECTION BETWEEN PIN 3 AND OUTER SPACERS 2 OF THE WHEEL DISC, RESISTANT TO THE STRESSES THAT APPEAR, EFFECTIVE IN BOTH AXIAL DIRECTIONS. DEPENDING ON THE INVENTION EACH OF THE SPINDLES INCLUDES EITHER ONE OR TWO CIRCULAR GROOVED LINKS 5 BALLS 4, EACH PAIR OF CIRCULAR GROOVES RECEIVING THE BALLS BEING ARRANGED ON THE PERIOD OF THE SPINDLE AND OF THE WALL OF THE CORRESPONDING BALL.

Description

The invention relates to a blocking device against the offset

  axial of the pins in the bores of the spacers of the head of the wheel disk and the struts

  mobile blades of axial steam turbines and the like.

  Axial blockages of this type are known, or the pins are riveted. Riveting has certainly proven itself, but for larger pins, there are difficulties, especially due to the material. Another type of axial blockage is the matting or deformation

outer edge of the bores.

  The object of the invention is to provide axial locking

  of the above type in which - without riveting or matting -

  a connection can be obtained between the pins and the

  outer tops of the wheel disk, resistant to axial forces and bending moments appearing, and effective

in both axial directions.

  According to the present invention, this result is obtained by the fact that each pin comprises at least one geometric connection of the groove-circular type, each pair of grooves receiving the balls being arranged

  on the periphery of the spindle and the wall of the bore cor-

  sponding. With this provision: = n not only gets

  axial centering of the pins, but also

  linear contact between balls and groove - because of the point of attack of the eccentric forces - the appearance of irregular stresses is compensated by a local creep. In addition, there is now a greater choice of materials for

  pins, the riveting being removed.

  According to another characteristic of the present invention,

  vention, the pins are blocked by two groove-

  circulars / balls, provided in the area of the outer struts

  inside the wheel disc. thanks to this provision

  avoids the axial widening of the wheel head, respectively

  bending of the outer wheel spacers and one

  loosening of the interlocking links.

  Since the raceways of the balls plastically deform under a large load, increasing stress between the balls and their corresponding raceway causes the formation of a game. To avoid such a game, we can, according to another characteristic

  of the invention, preload the pins

  naked. Thus, the expected lamination can be omitted. As the balls are inserted through filler grooves, according to a feature of the invention, these grooves can be closed. This avoids

  The logs do not come out during transport or other

stances.

  In the drawing is schematically represented an example

ple of the invention.

  FIG. 1 is an extract from a side view of a rotor disk BP, provided with a connection according to the invention, and FIG. 2 is a sectional view along line A-A.

of Figure 1.

  1 denotes a wheel disc head whose spacers have cylindrical bores 2, through which cylindrical pins 3 are inserted,

  which are used to fix the wingings

  biles in the area of their straddling. The axial locking of the pins 3 is performed by geometric connections by means of small balls 4, for example 3 to 5 mm in diameter, arranged in the corresponding circular grooves 5, perpendicular to the axis of the spindle. The circular grooves are each formed by two grooves in the form of a semicircle, one of them being provided in the pin 3 and the other

  in the outer spacer of the wheel disc head.

  The balls 4 are placed in place by means of the grooves 6, parallel to the corresponding bore axes, which, which is not shown in the drawing, can be

  shutter pieces, for example goupil-

  the fluted. Circular grooves 5 are generally

  completely filled with marbles.

  For the locking of a spindle 3 against an axial offset, a unilateral arrangement of the geometrical connections 4, 5 is sufficient; however, to avoid enlargement of the wheel disc head, the geometric connection 4, 5

is used on both sides.

  Each pin 3 of the bending attachment is axially locked by the one or more circular-groove / ball connections.

  The pins 3 can in addition still be

  in a known manner (axially), for example as in

bolted joints.

  As application possibilities there are turbo-

  axial machines, whose movable fins are subject

  at high stresses due to centrifugal force, such as

  such as the long last fins of the high-power steam wafer parts BP; movable blades of gas turbines, axial compressors

in propellants and the like.

Claims (4)

CLAIMS:   1) Locking device against the axial shift of the spindles in the bores of the spacers of the wheel disc head and of the movable fin motions of axial steam turbines, gas turbines, compressors and the like, characterized in that each pin (3) has at least one geometric connection of the groove type   circular (5) / balls (4); each pair of circumferential grooves   the balls receiving the balls (4) being disposed on the periphery of the pin (3) and the wall of the bore (2) corresponding.   2) Axial locking device according to the claim   1, characterized in that each pin (3) is   blocked by two links (4, 5) with circular grooves   the, arranged in the area of the outer struts of the wheel disk.   3) Axial locking device according to one of the   1 or 2, characterized in that the pins (3) are prestressed.   4) Axial locking device according to one of the   1 to 3 in which the balls can be inserted through a filler groove, characterized   in that the filling groove (6) can be ob- tured.