# Research on Vibration Reduction in the Transmission System of Plastic Centrifugal Pump
## 1 Introduction  
With the continuous extension of the application scenarios of centrifugal pumps, people have put forward requirements of being able to work under harsh conditions, especially in situations such as high concentrations of acid or alkali, which make plastic centrifugal pumps stand out, and quickly obtain attention and favor from enterprises due to their strong corrosion resistance, light overall weight, and low price advantages. Centrifugal pumps are mechanical devices that use centrifugal force generated by rotating impellers to facilitate fluid flow. Widely used in industries such as water management, chemistry, and shipbuilding, these pumps are integral to various applications. However, at present, the plastic centrifugal pumps on the market generally have high vibration and low efficiency, of which the vibration problem is particularly prominent. Presently, the design of their transmission systems is predominantly based on traditional metal pump design methods. This approach often fails to adequately consider the dynamic and static characteristics of plastic centrifugal pumps, as well as the structural parameters of pump shafts, leading to prevalent vibration issues. Vibrations can degrade equipment performance, cause mechanical wear, and may even shorten the lifespan of key components. The geometric parameters of hydraulic components are crucial in determining the vibration excitations generated by plastic centrifugal pumps. [PERSON] et al. developed a flow model within the centrifugal pump impeller, incorporating calculations of fluid flow in inter-blade channels of centrifugal impellers with a finite number of blades, the construction of impeller energy characteristics, and the optimization of blade numbers for impeller energy characteristics [1]. [PERSON] et al., in their study of the characteristics of vibration signals post-damage to centrifugal pump end faces, measured vibrationsignals in scenarios of seal damage. They discovered that mechanical seal wear leads to high-frequency vibration signals, and fluid instabilities contribute to high amplitude characteristics of these signals [2]. [PERSON] et al. conducted a three-dimensional steady-state Computational Fluid Dynamics (CFD) analysis of industrial centrifugal pumps under five different discharge conditions. They utilized Multiple Reference Frame (MRF) technology for the numerical simulation of the steady flow field in both rotating impellers and stationary pump casings [3]. [PERSON] et al. undertook experimental and numerical studies on shaft fracture failures in centrifugal pumps used in diesel engine cooling systems, identifying the causes of shaft fractures [4]. [PERSON] et al. used computational models to investigate the cavitation performance of semi-open impeller radial flow centrifugal pumps. They extracted curves showing the total head drop with changes in cavitation parameters through numerical simulations and experiments, comparing these curves under various pump load conditions [5]. [PERSON] et al. introduced a novel impeller structure with a protective cover and explored its effects on the head and efficiency of semi-open centrifugal pumps through experimental and numerical methods [6]. [PERSON] et al. employed vibration analysis technology, using both time domain and frequency domain methods, to study the detection of impeller blade cracks in centrifugal pumps. They confirmed that with an increasing crack size in the blades, the amplitude of the passed frequency and the vibration time index in the impeller increased [7]. [PERSON] et al. researched the effects of axial rotor offset in the final stage of a three-stage centrifugal pump and summarized the causes [8]. [PERSON] et al. utilized an inverse dynamics approach to study the impact of impeller diameter on the dynamic response of centrifugal pumps. The results indicated that increasing the impeller diameter at the rotor's critical speed could increase the vibration amplitude by 52% [9]. [PERSON] et al.