舰船尾轴承变形对其阻尼特性的影响研究

Research on the Influence of Ship Stern Shaft Deformation to Journal Bearing Lubricant Property

舰船推进轴系受多个载荷的作用,导致船体、螺旋桨轴和尾轴承发生变形,并在尾轴承中心线与螺旋桨轴颈中心线之间形成一个变形角。研究了变形夹角对轴承油膜动态阻尼参数的影响关系,用数值计算的方法计算得到了轴承油膜阻尼参数与变形角之间的变化关系。结果表明:轴承中线与轴颈轴线之间的变形夹角对轴承润滑阻尼参数的影响关系为强的非线性关系;变形角对轴承阻尼特性影响较大,随着变形角的增大,油膜阻尼Dxx和Dyy会增大,而阻尼Dyx和Dxy会减小;轴颈中线与轴承中线之间夹角对油膜阻尼参数的影响局限在一定的弯曲变形范围内,当变形继续增大时,螺旋桨轴与尾轴承发生刚性接触,此时轴与轴承的刚性接触摩擦作用增大,阻尼作用急剧改变。

The marine propulsive shafting is applied by many external loads. These loads make the ship body, propeller shaft and stern ship journal bearing deform seriously, and an angle is produced between the central axes of the propeller shaft neck and the stern journal bearing. The influence of the deformation angle on the dynamic damping parameters of journal bearing lubrication oil film was researched. The relation between the bearing oil film damping property and the deformation angle was obtained and analyzed by numerical method. The calculation results show that the relation of the angle between the central axes of bearing and shaft neck to the damping property of bearing lubrication oil film is distinctly non- linear. The deformation angle obviously influences the bearing oil film damping property. The damping coefficients Dxx, and Dyy, increase,and the damping coefficients Dyx and Dxy decrease,while the angle increases. However,the influence between the deformation and the bearing oil film damping property is limited in a deformation range. With the deformation increasng,they directly contact between the propeller shaft and stern ship journal bearing,the contact condition is rigid, so the friction increases and the damping varies sharply.