NVESTIGATION OF RELIABILITY OF THE SCREW UNIT OF THE COAL-ROLL PRESS BТ-3М

Аннотация

In the article we propose the method of calculation of parameters of stress state and rigidity of screw
blade at bending in one plane, screw-piston press of BТ-3М grade for production of coal briquettes is simultaneously
mixing, transporting and pressing unit. The blade is regarded as a thin axially endless helicoid shell rigidly attached
to the shaft along an internal helical boundary. Considering that the presence of the blade does not affect the
deformation of the constant-section shaft during bending, we examine the effect of the presence of the blade on the
bending stiffness of the screw. Invention covers the problem of screw blade deformations at preset displacements at
inner boundary caused by shaft bending considering that its axis has curvature.
In the second stage of calculation we construct a compensating solution, which eliminates inconsistencies in
differential equilibrium equations and static boundary conditions, and on the inner contour of the shell we set
conditions of rigid pinching. As a result, the screw was calculated using the developed method. Blade is calculated
with parameters r1 = 0.04 m, r2 = 0.1 m, r3 = 0.03 m, screw blade thickness d = 0.005 m, L = 0.2 m, total length of
hollow shaft 1, 2 m. Calculations have shown that at such screw parameters and created specific pressure of material
on the screw Ore = 8.5 · 105
Pa, the rigidity of the blade is the stiffness 11% of the tubular shaft