I. Resonance Caused by Over‑Short and Over‑Thin Oil Pipes
When the hydraulic oil pipes connected to the handle are both too short and too thin, resonance can be triggered from two perspectives. From a fluid mechanics standpoint, thin pipes restrict the flow cross‑section of hydraulic oil, increasing the flow velocity of the oil inside the pipeline and intensifying pressure pulsation. Such pressure pulsation generates periodic exciting forces that act on the pipe wall. Meanwhile, short pipes feature high rigidity and a relatively high natural frequency. When the exciting frequency of the hydraulic oil pressure pulsation approaches or matches the natural frequency of the pipe, resonance of the oil pipe occurs, which is then transmitted to the handle through the hydraulic system, resulting in noticeable handle vibration. In addition, short pipes are unable to buffer minor displacements of the entire machine during operation, and are prone to extra mechanical vibration caused by stretching or compression, further worsening the resonance of the handle.
II. Resonance Caused by Over‑Long Oil Pipes in Contact with the Entire Machine
An excessively long oil pipe is the key prerequisite for inducing this type of resonance. Long pipes have a low natural frequency, making it easier for their frequency to match the excitation frequency in the system and trigger resonance. Furthermore, if long oil pipes are not properly secured, they will swing during machine operation due to their own gravity and the impact force of flowing oil. When the swinging pipes come into contact with other components of the machine, a rigid transmission path is formed. On one hand, the vibration generated during machine operation is directly transmitted to the oil pipes through the contact points; the pipes then vibrate accordingly and transfer the vibration energy to the handle. On the other hand, the superposition of the pipe’s own swing and the machine’s vibration may induce coupled resonance, significantly increasing the amplitude of handle vibration. Moreover, long‑term contact and friction between the oil pipes and the machine can loosen the pipe fixing structures, further reducing the stability of the oil pipes and exacerbating the persistence and severity of resonance.
Post time: Feb-07-2026