BEM-12-20-501 德国DURBAL轴承,OF4404T货期价格,OF4404T图纸参数,OF4404T采购交期 BEM-12-20-501型号尺寸，BEM-12-20-501轴承价格,BEM-12-20-501采购 R17724重量,R17724尺寸,R17724参数