Abstract: Thin range hoods adopt exist with dual outlets design, one of which is in poor working condition. In order to study the vibration of the machine under poor working condition, vibration tests were carried out on the original machine. The test results show that the wind volume of the whole machine increased, the vibration velocity value significantly increased, reaching a maximum of 9.32 mm/s. According to the structural characteristics of the machine and the pattern of vibration changes, the root cause of the problem was identified as insufficient rigidity of the motor mounting plane, which failed to block the disturbances from the impeller from being transmitted to the machine case, resulting in machine vibration. In view of this issue, the vibration problem of the whole machine was simplified as a rigidity design issue related to the presence of a large notched plane. Longitudinal stiffeners, circumferential stiffeners, and other combinations of stiffener designs were created. The effects of different stiffeners on rigidity were evaluated through static simulations, which showed that circumferential stiffeners improved rigidity more effectively than radial stiffeners. The optimal design was selected for experimental validation, demonstrating that the maximum vibration speed of the whole machine was reduced from 9.32 mm/s to 2.97 mm/s, significantly improving the machine's vibration problem.

Key words: Thin range hood, Vibration simulation, Poor working condition, Experimental verification