Design and Stress Analysis of Extraterrestrial ... - The Black Vault

Fig. 3.11. Union of disk
with shaft: a - with a
centering band and radial
pins; b - by welding.
KEY: (1) Force fit. (i)
n7pecco~afl
nocadira
(a)
(b)
Joints between disks (in multistage turbines) and between a
disk and the shaft are critical points in turbine design. These
nodes must have high mechanical strength in order to transmit torque
and axial forces and ensure the reliable installation of adjacent
parts under all operating conditions as well as sufficient flexural
stiffness for the rotor.
Connections of disks to each other or to the shaft can be
dismountable. However, for simplicity and reliability these Joints
are better made nondismountable, for example, pressing the disk
to a central collar on- the shaft (Fig. 3.4a) or another di sk and
installing radial pins on the force fit.
The simplest is the connection of a disk to the shaft by welding
(Fig. 3. 1 1b) or by forging the disk and the shaft as one piece (with
small rotor dimensions).
Nozzles consist of nozzle blades forming a circular cascade
and bands forming the outer and inner walls of a ring-shaped system
for the working medium.
The dimensions and shape of nozzle blades are determined on the
basis of gas-dynamic analysis.
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