趙景周,郝亞碩,王國平,袁耀東
(洛陽LYC軸承有限公司 大型軸承廠檢查科,河南 洛陽 471039)
大型球軸承使用的工況多為礦山、冶金等設備的一般非精密部位,一般沒有噪聲方面的特殊要求。但隨著科技的發展,大型球軸承噪聲問題已越來越被關注。根據小型低噪聲球軸承的生產加工經驗可知,鋼球精度對軸承振動噪聲的影響最大;其次是內圈溝道(內溝)的圓度、波紋度和表面粗糙度;再次是外圈溝道(外溝)的圓度、波紋度、表面粗糙度及軸承潤滑劑和軸承的清潔度;保持架的加工精度和軸承的游隙對噪聲的影響最小。為此在生產加工過程中,應重點對大型球軸承零件的圓度、波紋度和表面粗糙度進行嚴格控制,以達到控制軸承噪聲的目的。
為了分析影響大型球軸承噪聲的因素,進行了多次多型號(6320,6322,6324)軸承的工藝試驗,現以6320軸承為例進行分析。為了保證產品零件的加工質量,對套圈的磨削加工質量和工藝路線進行了相應調整。套圈的加工質量按6級公差進行質量控制,用YD-201Taylor圓度儀隨機測量,結果見表1。

表1 套圈加工質量測量結果 μm
鋼球等級選取G20,保持架按一般品的質量要求,潤滑劑選取991抗磨減振潤滑劑。合套后用汽油清洗,待汽油揮發盡涂油后在BVT-120速度振動儀上進行測量,結果見表2。
采用灰關聯分析[1]方法對軸承零件內、外溝的圓度、波紋度、表面粗糙度與產品的低、中、高頻振動噪聲關系進行分析計算,不考慮鋼球、保持架、潤滑劑、游隙和軸承清潔度對噪聲的影響。
根據灰關聯分析法,由表2數據可得

表2 軸承振動速度值及零件加工質量對照
X=[XD,XZ,XG,X2,X3,X4,X5,X6,X7]T=

式中:XD,XZ,XG分別代表低、中、高頻分量;X2,X3,X4分別代表外溝圓度、波紋度和表面粗糙度;X5,X6,X7分別代表內溝圓度、波紋度和表面粗糙度。
以第1列數據為基準,對數據序列進行初值化變換,得
X[0]=

由Δij(t)=|Xi-Xj|得
低頻,
QD2=[0,0.069,0.143,0.251,0.275,0.081,0.258],
QD3=[0,0.048,0.286,0.143,0.552,0.229,0.181],
QD4=[0,0.067,0.143,0.352,0.029,0.324,0.152],
QD5=[0,0.054,0.008,0.232,0.126,0.111,0.032],
QD6=[0,0.24,0.137,0.206,0.171,0.097,0.194],
QD7=[0,0.375,0.143,0.036,0.421,0.443,0.039];
中頻,
QZ2=[0,0.331,0.533,1.432,2.297,0.528,2.294],
QZ3=[0,0.352,0.390,1.323,2.019,0.381,2.371],
QZ4=[0,0.467,0.533,1.533,2.6,0.933,2.4],
QZ5=[0,0.454,0.668,1.412,2.697,0.721,2.520],
QZ6=[0,0.64,0.813,1.387,2.4,0.707,2.747],
QZ7=[0,0.025,0.533,1.217,2.15,1.667,2.592];
高頻,
QG2=[0,0.014,0.833,0.966,2.229,0.862,1.494],
QG3=[0,0.357,0.690,0.857,1.952,0.714,1.571],
QG4=[0,0.15,0.833,1.067,2.533,1.267,1.6],
QG5=[0,0.137,0.968,0.946,2.63,1.054,1.721],
QG6=[0,0.323,1.113,0.92,2.333,1.04,1.947],
QG7=[0,0.292,0.833,0.75,2.083,0.5,1.792],
式中:Δij(t)為比較時刻的因素間的絕對值;Xi為數列,i=D,Z,G;Xj為數列,j=2,…,7。
找出Δij(t)的最小值Δmin和最大值Δmax。低頻的最大值為0.552,最小值為0;中頻的最大值為2.747,最小值為0;高頻的最大值為2.631,最小值為0。
求Xi對各數列每個時刻的關聯系數(分辨系數K=0.5)
Lij(t)=(Δmin+KΔmax)/(KΔmax+Δij(t)),
式中:K為常數,0.1≤K≤1,一般取K=0.5;Δmin為各個因素間的最小值;Δmax為各個因素間的最大值。
RD2=[1,0.800,0.659,0.523,0.501,0.774,0.517],
RD3=[1,0.853,0.491,0.659,0.333,0.547,0.604],
RD4=[1,0.805,0.659,0.439,0.906,0.460,0.644],
RD5=[1,0.836,0.973,0.544,0.687,0.713,0.897],
RD6=[1,0.535,0.668,0.573,0.617,0.740,0.587],
RD7=[1,0.424,0.659,0.885,0.396,0.384,0.875];
RZ2=[1,0.806,0.720,0.49,0.374,0.722,0.374],
RZ3=[1,0.796,0.779,0.509,0.405,0.783,0.367],
RZ4=[1,0.746,0.720,0.473,0.346,0.595,0.364],
RZ5=[1,0.752,0.673,0.493,0.337,0.656,0.353],
RZ6=[1,0.682,0.628,0.498,0.364,0.660,0.333],
RZ7=[1,0.982,0.720,0.530,0.390,0.892,0.346];
RG2=[1,0.989,0.612,0.577,0.371,0.604,0.468],
RG3=[1,0.974,0.656,0.605,0.403,0.648,0.456],
RG4=[1,0.898,0.612,0.552,0.342,0.509,0.451],
RG5=[1,0.905,0.576,0.582,0.333,0.555,0.433],
RG6=[1,0.803,0.542,0.588,0.361,0.558,0.403],
RG7=[1,0.819,0.612,0.637,0.387,0.725,0.423]。
式中:rij為關聯度;M為數據個數;Lij(t)為關聯系數。
rD2=0.68,rD3=0.64,rD4=0.70,rD5=0.81,rD6=0.67,rD7=0.66,則對低頻的影響排序為:內溝圓度>外溝表面粗糙度>外溝圓度>內溝波紋度>內溝表面粗糙度>外溝波紋度。
rZ2=0.641,rZ3=0.663,rZ4=0.606,rZ5=0.609,rZ6=0.595,rZ7=0.694,則對中頻的影響排序為:內溝表面粗糙度>外溝波紋度>外溝圓度>內溝圓度>外溝表面粗糙度>內溝波紋度。
rG2=0.729,rG3=0.703,rG4=0.783,rG5=0.739,rG6=0.720,rG7=0.715,則對高頻的影響排序為:外溝波紋度>外溝圓度>內溝表面粗糙度>內溝圓度>外溝表面粗糙度>內溝波紋度。
軸承內、外溝圓度,波紋度及表面粗糙度對軸承噪聲的影響程度不同,在實際的大型低噪聲球軸承生產加工中,首先應重點控制內、外溝的表面粗糙度和內溝道的波紋度,其次控制內、外溝的圓度和外溝的波紋度,即可達到和保證產品的噪聲水平。