Page 147 - 摩擦学学报2025年第10期

1544 摩擦学学报（中英文） 第 45 卷

2.5 长径比对油膜动特性影响分析 体数值较小. 如图10(b)所示，油膜宽度增大，阻尼增
为了研究长径比对空气吸入SFD油膜动特性系数 大，这是因为流体受挤压时流动路径增长，流动形态
影响规律，确定油膜直径140 mm，不考虑静偏心距， 复杂，作用面积增大；空气吸入时，阻尼增幅及具体数

选取典型油膜宽度范围10~40 mm开展分析，提取吸入/ 值较小. 如图10(c)所示，油膜宽度增大，无空气吸入时，
无吸入情况下的动特性系数，其分布规律如图10所示. 等效阻尼线性增大；空气吸入时，等效阻尼增幅及具
如图10(a)和(d)所示，阻尼和刚度沿周向坐标变化 体数值较小. 如图10(e)所示，油膜宽度增大，刚度增大；

幅值较小，这是因为未设置静偏心，不同坐标下最小 小于20 mm时，空气吸入对刚度影响较小；大于20 mm
膜厚相似，动压效应相近；空气吸入时阻尼和刚度整 时，空气吸入使得刚度显著降低. 如图10(f)所示，油膜

20 16 With air ingestion Without air ingestion

18 With air ingestion Without air ingestion θ=90° θ=90°
10 mm
10 mm
16 20 mm 20 mm 14 θ=180° θ=180°
30 mm
30 mm
θ=270°
θ=270°
12
Damping/(10 3 N·s/m) 12 8 6 Damping/(10 3 N·s/m) 10 8 6
14
40 mm
40 mm
θ=360°
θ=360°
10
2 4 4 2
0 0
30 60 90 120 150 180 210 240 270 300 330 360 10 15 20 25 30 35 40
Circumferential coordinate/(°) Oil film width/mm
(a) Variation of damping along the (b) Damping change diagram
circumferential coordinates
16 5.0 70
Without air ingestion 4.5 60 With air ingestion Without air ingestion
14
10 mm
10 mm
With air ingestion
Equivalent damping/(10 3 N·s/m) 10 8 6 4 3.5 Without/with air ingestion Stiffness/(10 5 N/m) 40
20 mm
20 mm
Without/With air ingestion
30 mm
30 mm
12
4.0
50
40 mm
40 mm
3.0
30
2.5
20
2.0
2
1.5
0
1.0 10 0
10 15 20 25 30 35 40 30 60 90 120 150 180 210 240 270 300 330 360
Oil film width/mm Circumferential coordinate/(°)
(c) Graph of the change of negative work (d) Variation of stiffness along
done by oil film on the journal circumferential coordinates
50 40
45 With air ingestion Without air ingestion 35 With air ingestion
40 θ=90° θ=90° 30 Without air ingestion
θ=180°
θ=180°
θ=270°
θ=270°
Stiffness/(10 5 N/m) 30 Average stiffness/(10 5 N/m) 25
35
θ=360°
θ=360°
20
25
20
15
15
10 10
5 5
0 0
10 15 20 25 30 35 40 10 15 20 25 30 35 40
Oil film width/mm Oil film width/mm
(e) Stiffness variation diagram (f) Average stiffness variation graph
Fig. 10 Effect of oil film width on dynamic characteristics at 4 typical moments with/without air ingestion
图 10 考虑空气吸入/不考虑空气吸入在4种典型时刻下油膜宽度对动态特性影响