今天详细介绍下SKF的混合陶瓷轴承。这种轴承除了有良好的电绝缘特性外，

Today we will introduce SKF's hybrid ceramic bearings in detail. In addition to good electrical insulation characteristics, this type of bearing can also run at higher speeds. In most applications, the working life is longer than traditional steel bearings. <br><br><br>SKF's hybrid ceramic bearings are composed of bearing rings made of bearing steel and rolling elements made of silicon nitride (Si3N3). In addition to good electrical insulation characteristics, this type of bearing can also run at higher speeds. In most applications, the working life is longer than traditional steel bearings. <br><br>Hybrid ceramic bearings further improve electrical insulation performance, especially for high frequency inverter applications. SKF hybrid ceramic bearings have the following excellent properties, making them popular in ultra-high-speed precision equipment and frequency conversion motors. <br><br>1. Insulation performance. <br><br>Non-conductive silicon nitride rolling elements protect the bearing from passing current, thereby extending the service life of the bearing, because the destructive bearing current will quickly shorten its service life. <br><br>2. Low density. <br><br>The density of bearing-grade silicon nitride rolling elements is 60% lower than that of bearing steel rolling elements of the same size, which means light weight, less inertia, faster start-stop performance, and higher speed. <br><br>3. Low friction coefficient. <br><br>The low density of silicon nitride rolling elements, coupled with its low friction coefficient, can greatly reduce the bearing temperature during high-speed operation. Low temperature operation can extend the service life of bearings and lubricants. <br><br>4. High hardness and elastic modulus. <br><br>The high hardness of silicon nitride rolling elements can improve the wear resistance, stiffness and service life of bearings in a polluted environment. When the steel rolling elements excessively crush the solid contaminants, due to plastic deformation, indentations on the raised edges will be formed in the raceway and on the rolling elements. As the rolling elements continue to excessively crush the raised edges, high local stresses will cause spalling, resulting in premature bearing damage. <br><br>However, hybrid ceramic bearings respond differently to over-crushing damaged areas. Due to the high hardness of silicon nitride, the rolling body will smooth the raised edges of the indentation until the raceway returns to smooth, which will reduce the chance of local stress and spalling, thereby significantly extending the life of the bearing. <br><br><br>5. Anti-false Brinell indentation.<br><br>When the bearing is at rest, there is a risk of pseudo-Brinell indentation due to vibration. Pseudo-Brinell indentation is an impression produced on the raceway, which will eventually lead to premature bearing failure. After the ceramic rolling element replaces the steel rolling element, the pseudo Brinell indentation will be significantly reduced. <br><br>6. The risk of adhesive wear between silicon nitride and steel surface is reduced. <br><br>Even in the case of insufficient lubrication conditions, the risk of adhesion wear between silicon nitride and the steel surface will be very low. This makes the hybrid ceramic bearings run longer in high-speed and high-acceleration applications or in applications with insufficient dynamic oil film. <br><br>7. Low coefficient of thermal expansion. <br><br>The thermal expansion coefficient of silicon nitride rolling elements is lower than that of bearing steel rolling elements of the same size. This means that it is less sensitive to the temperature gradient in the bearing and the preload and clearance can be controlled more accurately. <br><br>8. Long grease life. <br><br>Hybrid ceramic bearings produce less frictional heat than all-steel bearings of the same size, especially at high speeds. Lower bearing operating temperature has a beneficial effect on extending the service life of the bearing and the time interval for relubrication. Depending on the application and operating conditions, the service life of the grease can be extended at least twice. <br><br>SKF hybrid ceramic bearings have so many excellent properties that are very worthy of promotion and use. The only drawback is that they are a little expensive! Therefore, hybrid ceramic bearings are only used in high-speed precision equipment, high-voltage frequency conversion motors and generators. It is the hybrid ceramic bearings that cannot be solved by other bearings.

今天详细介绍下SKF的混合陶瓷轴承。这种轴承除了有良好的电绝缘特性外，还可以在更高的转速下运行，在大部分的应用中，工作寿命都比传统轴承钢轴承要长。<br><br><br>SKF的混合陶瓷轴承是由轴承钢制成的套圈和氮化硅（Si3N3）制成的滚动体组合而成的。这种轴承除了有良好的电绝缘特性外，还可以在更高的转速下运行，在大部分的应用中，工作寿命都比传统轴承钢轴承要长。<br><br>混合陶瓷轴承进一步改善了电气绝缘性能，特别是对于高频变频器的应用场合。SKF混合陶瓷轴承具有如下的优良性能，使其可以在超高速精密设备及变频电动机等设备中备受青睐。<br><br>1、绝缘性能。<br><br>非导电氮化硅滚动体保护轴承不致有电流通过，从而延长轴承的使用寿命，因为破坏性的轴承电流将会很快缩短其使用寿命。<br><br>2、密度低。<br><br>轴承级氮化硅滚动体的密度比相同尺寸的轴承钢滚动体低60%，这就意味着重量轻、惯性较小、快速启停性能更优越，转速更高了。<br><br>3、摩擦系数低。<br><br>氮化硅滚动体的密度低，再加上其低摩擦系数，可以在高速运行时大大降低轴承温度。低温运行可以延长轴承和润滑剂的使用寿命。<br><br>4、硬度和弹性模量高。<br><br>氮化硅滚动体硬度高可以提高轴承在污染环境中的耐磨性、刚度和使用寿命。钢制滚动体过度碾压固体污染物时，由于塑性变形，会在滚道中和滚动体上形成有凸起边缘的压痕。由于滚动体持续过度碾压凸起的边缘，较高的局部应力将会导致剥落，致使轴承过早损坏。<br><br>但是，混合陶瓷轴承对过度碾压受损区域的反应不同。由于氮化硅硬度高，滚动体会将压痕的凸起边缘磨平，直到滚道恢复平滑，这将减少局部应力和发生剥落的机会，从而显著延长轴承的使用寿命。<br><br><br>5、耐伪布氏压痕。<br><br>当轴承处于静止状态时，由于振动，存在发生伪布氏压痕的风险。伪布氏压痕是在滚道上产生的印痕，最终会导致轴承过早失效。陶瓷滚动体替代钢制滚动体后，伪布氏压痕会显著降低。<br><br>6、氮化硅和钢表面之间的粘着磨损风险降低。<br><br>即使在润滑条件不充分的情况下，氮化硅和钢表面之间的粘着磨损风险也会很低。这使得混合陶瓷轴承在高速和高加速度的应用场合或动压油膜不足的应用场合运行时间会更长。<br><br>7、热膨胀系数低。<br><br>氮化硅滚动体的热膨胀系数比相同尺寸的轴承钢滚动体低。这就意味着对轴承内的温度梯度较不敏感，可以更精确地控制预载荷与游隙。<br><br>8、润滑脂寿命长。<br><br>混合陶瓷轴承产生的摩擦热比相同尺寸的全钢轴承少，特别是在高速运行的情况下。较低的轴承运行温度对于延长轴承的使用寿命和补充润滑的时间间隔具有有利影响。根据应用场合和运行条件，润滑脂的使用寿命可以延长至少两倍。<br><br>SKF混合陶瓷轴承这么多的优良性能是非常值得推广使用的，唯一的缺点就是有点贵啊！所以混合陶瓷轴承只是在高速精密设备上、高压变频电动机上及发电机等设备上使用。就是别的轴承解决不了的地方，都由混合陶瓷轴承来承担了。

Today I will introduce the hybrid ceramic bearing of SKF in detail. This kind of bearing has not only good electrical insulation characteristics, but also can run at a higher speed. In most applications, its working life is longer than the traditional bearing steel bearing.<br>SKF's hybrid ceramic bearing is composed of a ferrule made of bearing steel and a rolling element made of silicon nitride (si3n3). This kind of bearing has not only good electrical insulation characteristics, but also can run at a higher speed. In most applications, its working life is longer than the traditional bearing steel bearing.<br>The hybrid ceramic bearing further improves the electrical insulation performance, especially for the application of high frequency converter. SKF hybrid ceramic bearing has the following excellent performance, which makes it popular in ultra-high speed precision equipment and frequency conversion motor and other equipment.<br>1. Insulation.<br>The non-conductive silicon nitride rolling element protects the bearing from current passing, thus prolonging the service life of the bearing, because the destructive bearing current will soon shorten its service life.<br>2. Low density.<br>The density of bearing grade silicon nitride rolling element is 60% lower than that of bearing steel rolling element of the same size, which means that the weight is light, the inertia is small, the quick start and stop performance is better, and the speed is higher.<br>3. Low friction coefficient.<br>The low density of silicon nitride rolling element and its low friction coefficient can greatly reduce the bearing temperature at high speed. Low temperature operation can extend the service life of bearings and lubricants.<br>4. High hardness and elastic modulus.<br>High hardness of silicon nitride rolling element can improve the wear resistance, rigidity and service life of bearings in polluted environment. When the steel rolling body over rolls the solid pollutants, because of the plastic deformation, there will be a raised edge indentation in the raceway and on the rolling body. As the rolling element continues to over roll the raised edge, high local stress will lead to peeling off, resulting in premature bearing damage.<br>However, the response of the hybrid ceramic bearing to the damaged area is different. Due to the high hardness of silicon nitride, rolling experience will grind the convex edge of the indentation until the raceway returns to smooth, which will reduce the local stress and the chance of peeling off, thus significantly extending the service life of the bearing.<br>5. Resistant to false Brinell indentation.<br>When the bearing is stationary, there is a risk of pseudo Brinell indentation due to vibration. Pseudo Brinell indentation is a kind of impression on raceway, which will eventually lead to premature failure of bearing. When the ceramic roller replaces the steel roller, the pseudo Brinell indentation will be significantly reduced.<br>6. The risk of adhesive wear between silicon nitride and steel surfaces is reduced.<br>Even in the case of insufficient lubrication, the risk of adhesive wear between silicon nitride and steel surfaces is low. This makes the hybrid ceramic bearing run longer in high-speed and high acceleration applications or applications with insufficient dynamic oil film.<br>7. The coefficient of thermal expansion is low.<br>The thermal expansion coefficient of silicon nitride rolling element is lower than that of bearing steel rolling element of the same size. This means that it is less sensitive to the temperature gradient in the bearing and can control the preload and clearance more accurately.<br>8. Long grease life.<br>The friction heat of hybrid ceramic bearing is less than that of all steel bearing of the same size, especially at high speed. The lower operating temperature of the bearing has a favorable effect on prolonging the service life of the bearing and the time interval of supplementary lubrication. According to the application and operation conditions, the service life of the grease can be extended at least twice.<br>So many excellent properties of SKF hybrid ceramic bearings are worth popularizing. The only disadvantage is that they are a little expensive! Therefore, the hybrid ceramic bearing is only used in high-speed precision equipment, high-voltage variable-frequency motor, generator and other equipment. Where other bearings cannot be solved, hybrid ceramic bearings are responsible for it.<br>