Effect of the elasticity of the mechanical part of an extruder takeup shaft on the dynamic characteristics of the electric drive

Abstract

A block diagram of the mechanical part of the extruder drive was developed. The effect of the elasticity of the mechanical part of the extruder takeup shaft on the dynamic characteristics of the electric drive was determined. The ACS quality indexes characterizing the dynamic properties of the extruder control channel were obtained.The multimotor, multimass electrical system for a controllable Reicofi l synthetic fi bre and nonwovens production complex consists of a number of concentrated and distributed masses joined by mechanical transmissions. In view of the possibilities of the equivalence of multimass mechanical systems, we will limit the examination to the mechanical part of the extruder takeup shaft in the form of two masses with an elastic weightless transmission that obeys Hooke's law. We assign the motor rotor masses, the clutch between the motor shaft and the reducing gear shaft, and the gear wheels to one of the masses on this shaft. We designate the total moment of inertia of these parts as the moment of inertia brought to the shaft of an AM -J 2 . We assign the mass of the screw channel that rotates in a cylinder with an inserted wear-resistant lining to another mass -J p p r c . The motor moment M d and elastic moment M e that counteracts it in the transmission will act from the motor in this system, and the elastic moment M e and counteracting moment M s will act from the screw channel. The rigidity of the mechanical transmission will be evaluated with rigidity coeffi cient C, and the viscous friction (including internal friction) in the material of the transmission takeup shaft will be evaluated with coeffi cient . With the simplifi cations applied, the equations of equilibrium of a calculated two-mass extruder drive system in dynamic conditions can be written in relative increments and operational form:(1)where µ d = M d /M s ; µ e = M e /M c ; µ s = M s /M s are the relative increments of the moments of the system; d/c, d=  d / s , T md = J 2  s /M s , T mm =  s /M s are the relative increments of the rotational speeds and mechanical time constants of the motor and working parts of the extruder brought to the takeup shaft;  s is the steady-state rotational speed of the motor; U d is the stator voltage of the asynchronous motor; T  = /C; T s = M s /(C s ) are time constants characterizing the dynamic properties of the elastic transmission; p is a differentiation operator.A block diagram of the mechanical part of the electrical system with consideration of the elasticity and clearance was compiled in accordance with Eqs. (1) (Fig.

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