The hydro-pneumatic suspension, known for enhancing vehicle ride comfort and stability, finds widespread use in engineering vehicles. Presently, the majority of mining trucks employ hydro-pneumatic suspension with a fixed damping hole, underscoring the critical importance of selecting appropriate damping hole parameters. Initially, an equilibrium mathematical model of the ¼ hydro-pneumatic suspension is established, and the influencing factors of the damping characteristics are analyzed. Subsequently, the simulation model and experimental bench for the hydro-pneumatic suspension are constructed. Sinusoidal signals with different frequencies and amplitudes serve as the excitation signals to analyze the variation trend of the force on the rod with displacement changes. The simulation and experimental results demonstrate a high degree of consistency, validating the rationality and validity of the simulation model. Building upon this foundation, various damping apertures are then selected to study the damping characteristics of the hydro-pneumatic suspension. The research indicates that as the damping aperture increases, the setting time of the hydro-pneumatic suspension system after excitation extends, accompanied by a decrease in the acceleration overshoot. As a result, a comprehensive evaluation index is developed, considering various factors, such as different weight setting times and peak longitudinal accelerations to assess the ride comfort of the suspension. This approach is then employed to determine the optimal damping aperture under both full-load and no-load conditions. The findings of this research offer valuable insights for the development of adaptive variable damping hydraulic suspensions, especially under variable load conditions.

In response to the challenges of identifying and reducing noise from multiple sources in construction machinery, this study focuses on a hydraulic source cart as the research subject and employs a sound-vibration fusion diagnostic method for noise identification. Firstly, by analyzing the noise distribution of hydraulic source car under different speed, the main source of noise is deduced. Then, by analyzing the vibration spectrum of each part and comparing with the noise test results, the frequency and location of the main noise are determined. The results show that this method can accurately identify the main noise source frequencies and locations under different gear positions. At 800 r/min, 1500 r/min, and 2600 r/min, the maximum sound pressure levels of the hydraulic source cart are 73.08 dB at the valve side, 75.89 dB at the reducer side, and 78.67 dB at the pump side, with the main source frequencies being 602 Hz, 450 Hz, and 390 Hz, respectively. The main source frequencies are 602 Hz, 450 Hz and 390 Hz, all of which are integer multiple frequencies of the gear pump meshing frequency at this gear position, so the gear pump is the main noise source, and the main noise reduction object of the cart is the gear pump and its valve body.