Phase-based self-balancing strategy and performance evaluation of a compact K-H-V planetary vibratory mixer under 43 g high-frequency excitation

Abstract

To address severe structural vibration and premature fatigue failure in compact high-frequency vibratory mixers, this study proposes an integrated small-teeth-difference planetary vibratory mixer with a phase-based self-balancing mechanism. The mechanism uses a fixed internal ring gear, an eccentric high-speed shaft acting as the carrier input, a planet gear, and a drum-shaped gear coupling to convert a single input into high-frequency orbital excitation and low-speed mixing output. A kinematic-dynamic model is established to clarify the coupling among the small-teeth-difference transmission, planetary motion, eccentric excitation, and inertial-force evolution. Multi-body dynamic simulations in ADAMS show a dominant excitation frequency of 75.08 Hz, which is close to the theoretical frequency of 75.26 Hz calculated from the input speed of 4515.6 r/min.Concrete mixing tests using a C35 mix further indicate that the proposed mixer reaches a 28-day compressive strength of 53.9 MPa within 80 s, representing a 31.5% increase in 28-day compressive strength compared with the conventional twin-shaft reference.Fracture morphology and cross-sectional observations suggest that high-frequency vibration improves aggregate dispersion and may contribute to improved interfacial transition zone (ITZ) behavior by mitigating weak interface-controlled failure. The proposed architecture provides a compact mechanical solution for coupling high-frequency vibration excitation with reliable low-speed mixing output.