Page 143 - 摩擦学学报2025年第10期
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1540                                   摩擦学学报(中英文)                                        第 45 卷

            吸入时,平均刚度略有增长,数值较小.                                 趋于稳定. 如图6(b)所示,无空气吸入时,静偏心率增
             2.2    静偏心率对油膜动特性影响分析                             大,阻尼值在3/4 T和T时刻增大,1/2 T和1/4 T时刻减
                为了研究静偏心率对空气吸入SFD油膜动特性系                         小,这是因为最小膜厚减小,靠近静偏心位置或向其
            数影响规律,选取典型静偏心率范围0.075~0.150开展                      运动时,动压效应增大,反之则反;空气吸入时,各时
            分析,提取吸入/无吸入情况下的动特性系数,得到其                           刻阻尼均趋于稳定,主要是因为流体黏度降低和最小

            分布规律如图6所示.                                         膜厚减小的耦合作用. 如图6(c)所示,静偏心率增大,
                如图6(a)所示,静偏心率增大,无空气吸入时,阻                       无空气吸入时,等效阻尼小幅增大;空气吸入时,数值
            尼沿周向坐标变化幅值增大;空气吸入时,变化幅值                            略有增长;两者情形下数值之比约为2.5,设计无端封


                   13                                             12

                   12   With air ingestion  Without air ingestion  11  With air ingestion  Without air ingestion
                   11 9      0.075           0.075                10 9       θ=90°           θ=90°
                                                                                             θ=180°
                                                                             θ=180°
                             0.100
                                             0.100
                                                                             θ=270°
                                                                                             θ=270°
                             0.125
                                             0.125
                   10
                   Damping/(10 3  N·s/m)  8 7 6 5                Damping/(10 3  N·s/m)  8 7 6
                                                                                             θ=360°
                                                                             θ=360°
                             0.150
                                              0.150
                    3 4                                            5 4
                    2                                              3
                    1                                              2
                     30  60  90 120 150 180 210 240 270 300 330 360  0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15
                             Circumferential coordinate/(°)                    Static eccentricity
                          (a) Variation of damping along the                (b) Damping change diagram
                            circumferential coordinates
                                                      4.0         35   With air ingestion  Without air ingestion
                             Without air ingestion
                    Equivalent damping/(10 3  N·s/m) 8 6 5 4  3.4 Without/with air ingestion  Stiffness/(10 5  N/m)  25    0.150    0.150
                                                      3.8
                             With air ingestion
                                                                  30
                                                                                            0.075
                                                                            0.075
                            Without/with air ingestion
                                                                                            0.100
                                                                            0.100
                                                      3.6
                     7
                                                                            0.125
                                                                                            0.125
                                                                  20
                                                      3.2
                                                      3.0
                                                                  15
                                                      2.8
                                                                  10
                                                      2.6
                                                      2.2
                     2 3                              2.4          5 0
                     0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15   30 60 90 120 150 180 210 240 270 300 330 360
                               Static eccentricity                          Circumferential coordinate/(°)
                       (c) Graph of the change of negative work           (d) Variation of stiffness along
                           done by oil film on the journal                 circumferential coordinates
                   30   With air ingestion  Without air ingestion  14     With air ingestion
                             θ=90°         θ=90°                          Without air ingestion
                   25        θ=180°        θ=180°                 12
                             θ=270°
                                           θ=270°
                  Stiffness/(10 5  N/m)  15                      Average stiffness/(10 5  N/m)  10 8
                                           θ=360°
                             θ=360°
                   20
                   10
                   5                                               6 4
                   0                                               2
                    0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15      0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15
                                Static eccentricity                             Static eccentricity
                           (e) Stiffness variation diagram               (f) Average stiffness variation graph
                    Fig. 6    Effect of static eccentricity on dynamic characteristics at four typical moments with/without air ingestion
                             图 6    考虑空气吸入/不考虑空气吸入在4种典型时刻下静偏心率对动态特性影响
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