Static And Dynamic Characteristics Analysis And Design Improvement Of The Inertial Shakeout Machine

The inertial vibration shakeout machine is one application of the inertial reciprocating machinery, its main role is to break and separate the casting pure foundry sand through the vibration. Due to the large quality of the casting and sands, which has great collisions to the shakeout machine, the fatigue failure will be found in the weaker parts of the internal structure of the shakeout machine in actual using process. Therefore, the study of structural strength and vibration analysis of the inertial vibration shakeout machine is very significant.In this paper, the 3D modeling software PRO/E was used for solid modeling and the statics and dynamics analysis was finished by the finite element analysis software ANSYS, the deformation and stress state of the shakeout machine was performed by applying a excitation force, which identified the weak parts of the structural strength; the kinematics analysis of the shakeout machine vibration system was simulated by the multi-body dynamics simulation software ADMAS, which performed the influence to the vibration conditions with exciting force load, spring stiffness and rotation speed of the eccentric block. The conclusions are as follows:1 In the static analysis, the maximum stress occurred at the motor side connected with the coupling boss of the shakeout machine when the machine is forced the up and down of the instantaneous maximum exciting force, the average stress was 30 to 40MPa, far less than the shakeout machine material yield strength, the shakeout machine structural strength meet the design requirements. The weight of the shakeout machine loses 15.6% after lightweight design, while the mechanical properties meet the design requirements.2 The first order modal frequency of the shakeout machine free modal is 38Hz, which is more conservative design because of the high natural frequency, and the body side is relatively weak, which is easily to be distortion under the high frequency vibration; applying spring constraints, the shakeout machine achieved optimal mode shape in the 4th-order mode (22Hz), for the vertical vibration in the vertical direction (Z direction).3 According to the harmonic analysis, the choice of shakeout machine operating frequency should avoid low-frequency and high-frequency range, in the operating frequency of 22Hz, node response amplitude reached 1.2mm, which can achieve the best shaker state and does not produce greater response amplitude to avoid distortion and unwanted resonance, thus prolonging the life of shakeout machine.4 Through the kinematics analysis of the shakeout machine vibration system, the vibration displacement, velocity and acceleration augment with the increasing of the exciting force and the rotation speed of the eccentric block, decrease with the increasing of the spring stiffness; and the vibration amplitude of the vibration system is influenced observably by the rotation speed of the eccentric block; at low rotational speed, the spring stiffness of the vibration system is not obvious to the vibration system, but the larger spring stiffness enables vibration system to stabilize faster.