Design of the magnetorheological mount with high damping force for medium speed diesel generators

Abstract

This paper investigates the controllable magnetorheological (MR) mount for the marine diesel-generator (D/G) sets. Sometimes, significant vibrations over the allowable limit are observed on the D/G sets due to their huge excitation forces. Because the severe vibration can lead to structural damages to the D/G sets, it should be reduced to below the limit. Although passive mounts with rubber isolators are usually used, the vibration reduction performance is not always sufficient. In addition, expecting that the vibration levels required by customers will get more severe, semi-active vibration isolation system needs to be developed. To the aim, the valve (flow) mode type of MR mount has been designed. Especially, the annular-radial configuration was adopted to enhance the damping force within the restricted space. The geometry of the mount has been optimized to obtain the required damping force and the magnetic field analysis has been carried out using ANSYS APDL. To verify the performance of the developed MR mount, excitation test was conducted and the dynamic characteristics were identified. Since damping property of the MR fluid is changed by the applied magnetic field strength and excitation frequency, responses to changing applied currents and frequencies were obtained. From the results, damping performance of the MR mount was evaluated.

High Loaded Mounts for Vibration Control Using Magnetorheological Fluids: Review of Design Configuration

“…However, the damping force of this design structure is relatively low and hence it cannot apply for the high loaded MR mount which requires the high inside pressures and large damping force. A similar structure to high loaded MR mount studied in [10] was presented by Kang et al [14] and Hung et al [15]. The configuration of this mount is shown in Figure 12.…”

Design and analysis of an innovative combined magneto-rheological damper-mount

“…The objective damping force in this study is maximize damping force following the yield force and the viscous force based equation (7) The objective damping force for this damper-mount is 25 kN [6,7,9]. As mentioned above, the damping force of piston is not large to control vibration completely.…”

“…Another special MR mount was also presented in [7]. The structure using in this study was similar to the structure in [6], but it was a new modification. Hence, this mount was also a high-loaded mount, and its central plate could self-adjusted its damping gap following the magnitude of excitations.…”

“…Structure of high-loaded MR mount is also developed and obtains the salient results [6,7,9]. In this study, a new design of damper-mount based on flow mode and shear mode of MR fluid is studied in this context.…”

“…Apart from MR damper, another structure of MR devices uses popularly in industry as MR mount. A new design of high-loaded MR mount for engine was presented in [6]. In this study, a new section valve for mount was studied, and the flow mode of MR fluid was applied in this design.…”