﻿ 校中状态对轴系横向振动传递特性影响研究
 舰船科学技术  2020, Vol. 42 Issue (6): 65-70    DOI: 10.3404/j.issn.1672-7649.2020.06.013 PDF

Research on the influence of shafting alignment condition on transverse vibration transmission characteristics
ZHANG Yang-yang, SUO Jun
Naval Research Academy, Beijing 100161, China
Abstract: Alignment condition is an important factor affecting propulsion shafting vibration, the coupled vibration of shafting and stern hull is an important excitation source to acoustic stealth performance. In this paper, the load calibration of a propulsion shafting is first carried out, and the influence of bearing displacement on the characteristics of bearing oil film is studied, thus the change of the supporting boundary condition of shafting before and after shafting alignment is determined. Then, the influence of alignment condition on the vibration transmission characteristics of the shafting is investigated by simulation and experimental verification. Results show that the load calibration can effectively suppress the vibration transmission of shafting at some peak frequency points.
Key words: shafting alignment     oil film characteristics     vibration transmission
0 引　言

1 某船推进轴系负荷校中 1.1 轴系简化模型及参数

 图 1 轴系模型 Fig. 1 Shafting model

 图 2 轴系载荷分布 Fig. 2 Load distribution of shafting

1.2 轴系负荷校中 1.2.1 轴系负荷校中

1.2.2 轴承变位的处理

 $\frac{\partial }{{\partial x}}(\frac{{{h^3}}}{\eta } \cdot \frac{{\partial p}}{{\partial x}}) + \frac{\partial }{{\partial z}}(\frac{{{h^3}}}{\eta } \cdot \frac{{\partial p}}{{\partial z}}) = 6U\frac{{\partial h}}{{\partial x}} + 6V\frac{{\partial h}}{{\partial z}} + 12V\text{。}$ (1)

 图 3 径向滑动轴承油膜分布示意图 Fig. 3 Sketch map of oil film distribution of radial sliding bearing

 $\frac{\partial }{{\partial x}}(\frac{{{h^3}}}{\eta } \cdot \frac{{\partial p}}{{\partial x}}) + \frac{\partial }{{\partial z}}(\frac{{{h^3}}}{\eta } \cdot \frac{{\partial p}}{{\partial z}}) = 6U\frac{{\partial h}}{{\partial x}}\text{。}$ (2)

Reynolds边界条件认为液膜在轴承间隙内不是连续的，液膜在轴承扩散区的某处随着负压的增大而自然破裂，其边界条件为：

 $\left\{ {\begin{array}{*{20}{c}} {\varphi = 0,p = 0};\\ {\varphi = [{\varphi _2},2{\text π} ],p = 0,\displaystyle\frac{{\partial p}}{{\partial \varphi }} = 0}\text{。} \end{array}} \right.$ (3)

 图 4 油膜网格划分 Fig. 4 Mesh of oil film

 $e' = e + (i - 1)\Delta z \cdot \cos \alpha \text{，}$ (4)

 $e' = e - (i - 1)\Delta z \cdot \cos \alpha \text{，}$ (5)

 $\varepsilon ' = \frac{{e'}}{C}\text{。}$ (6)

 $h = C(1 + \varepsilon '\cos \theta )\text{。}$ (7)

 $K = \frac{{\partial F}}{{\partial x}} = \frac{{\Delta F}}{{\Delta x}} = \frac{{F' - F}}{{\Delta x}}\text{。}$ (8)
2 校中状态对轴系振动传递特性影响研究 2.1 校中状态对轴承油膜特性的影响

2.1.1 校中状态对轴承油膜刚度及轴颈倾斜角的影响

2.1.2 校中状态对油膜分布的影响

 图 5 两种校中状态下各轴承油膜压力分布 Fig. 5 Pressure distribution of oil film under two different alignment conditions

2.2 校中状态对轴系横向振动传递特性的影响

 图 6 两种校中状态下各轴承处的振动加速度传递函数 Fig. 6 Transfer function of vibration acceleration of bearings under two different alignment conditions

3 试验研究 3.1 试验台设计

 图 7 轴系试验台 Fig. 7 Test-bench of shafting

3.2 试验结果分析

 图 8 横向激励下各轴承处的振动加速度传递函数 Fig. 8 Vibration acceleration transfer function of bearings under transverse excitation
4 结　语

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