高精度陶瓷球的性能评价方法及其应用研究

发布时间：2018-11-21 08:48

【摘要】：随着现代机械工业的迅猛发展,陶瓷球轴承作为机械设备基础零部件,广泛应用于航空航天、精密机械、国防科技等领域。因此,对于高精度陶瓷球滚动体的数量需求及质量要求也越来越高。建立一个完善而有效的高精度陶瓷球质量评价体系十分必要。为进一步研究高精度陶瓷球的性能评价方法,本文以氮化硅陶瓷球为研究对象,主要在材料性能、几何形状精度及表面质量三个方面深入研究了球体的质量检测方法,球体的摩擦磨损性能,及球体加工工艺与球体质量的关系。在陶瓷球检测方法方面,重点研究球体振动值检测。采用BVT-1A球体振动测量仪,进行试验研究分析,初步规定G5级Φ4.763的氮化硅陶瓷球低频振动值不大于13μm/s,高频振动值不大于16μm/s;当表面存在缺陷时,振动值会异常变大;波纹度主要影响高频振动值,圆度主要影响低频振动值,粗糙度值的影响可忽略不计,验证了通过振动值分频测量快速了解陶瓷球表面几何质量的可行性。在陶瓷球的摩擦磨损性能方面,介绍了球轴承的摩擦来源以及其失效形式,高精度球体研磨技术,并以双自转研磨技术为例进行运动学分析;参照四球法,采用单因素实验分析压力、转速、磨料粒度、浓度对加工中陶瓷球摩擦系数的影响,发现高精度球体加工研磨盘的最佳转速为5rpm~15rpm;磨料浓度不宜过高或过低,过低会导致粘着磨损,而浓度为4%wt和7%wt时,摩擦系数接近,磨损量基本都随着磨料浓度的增大而增大;磨料粒度增大,摩擦系数也增大,为保证陶瓷球的表面质量,尽量选用粒度小的磨料;研磨压力不能过小,实验中载荷小于100N时,摩擦系数不稳定;而载荷过大、转速过高,均会使陶瓷球表面在周期性载荷作用下出现疲劳磨损。为了解陶瓷球的加工工艺对陶瓷球表面质量的影响,研究了加工过程中研磨介质和研磨参数对表面质量的影响,发现相比于碳化硼磨粒,氧化铝和碳化硅磨粒作用下的陶瓷球表面形状精度更高;研磨压力增大,球体表面粗糙度值增大,但幅度不明显;研磨时间并不是越长越好,需结合具体条件进行实验研究分析得到;详细介绍和分析了球体的表面缺陷,包括气孔缺陷、夹杂物、雪花缺陷、裂纹缺陷、划伤及擦伤、凹坑缺陷六类,并进一步分析了其对轴承失效的影响,体现了陶瓷球表面质量对轴承使用的重要性。
[Abstract]:With the rapid development of modern mechanical industry, ceramic ball bearings, as basic parts of machinery and equipment, are widely used in aerospace, precision machinery, national defense science and technology and other fields. Therefore, the demand for the quantity and quality of high precision ceramic ball rolling body is more and more high. It is necessary to establish a perfect and effective quality evaluation system for ceramic balls. In order to further study the performance evaluation method of high precision ceramic ball, this paper takes silicon nitride ceramic ball as the research object, mainly in three aspects of material performance, geometric shape precision and surface quality. The friction and wear properties of the ball, and the relationship between the ball processing technology and the ball mass. In the ceramic ball detection method, the focus is on the ball vibration detection. The low frequency vibration value of silicon nitride ceramic ball of grade G5 桅 4.763 is not more than 13 渭 m / s and the high frequency vibration value is not more than 16 渭 m / s by using BVT-1A ball vibration measuring instrument. When there is a defect on the surface, the vibration value will increase abnormally. The ripple degree mainly affects the high frequency vibration value, the roundness mainly affects the low frequency vibration value, and the influence of roughness value is negligible. The feasibility of quickly understanding the geometric quality of ceramic ball surface by frequency division measurement of vibration value is verified. In the aspect of friction and wear performance of ceramic ball, the friction source of ball bearing and its failure form, high precision ball grinding technology are introduced, and the kinematics analysis of double rotation grinding technology is carried out. Referring to the four-ball method, the effects of pressure, rotational speed, abrasive particle size and concentration on the friction coefficient of ceramic ball in machining were analyzed by single factor experiment. It was found that the best rotational speed of high precision ball grinding disk was 5rpmM ~ 15rpm; The abrasive concentration should not be too high or too low, too low will lead to adhesive wear. When the concentration is 4%wt and 7%wt, the friction coefficient is close, and the wear amount increases with the increase of abrasive concentration. In order to ensure the surface quality of ceramic ball, the abrasive with small particle size should be used as far as possible, and the friction coefficient is unstable when the load is less than 100N. However, if the load is too large and the rotational speed is too high, fatigue wear will occur on the surface of ceramic ball under periodic load. In order to understand the effect of machining technology of ceramic ball on surface quality of ceramic ball, the effects of grinding medium and grinding parameters on surface quality of ceramic ball were studied. The surface shape accuracy of ceramic ball under the action of alumina and silicon carbide abrasive particles is higher. When the grinding pressure increases, the surface roughness value of the ball increases, but the amplitude is not obvious. The longer the grinding time is, the better the grinding time is. The surface defects of the ball, including blowhole defects, inclusions, snowflake defects, crack defects, scratches and scratches, and pit defects are introduced and analyzed in detail, and the influence of the defects on bearing failure is further analyzed. The importance of the surface quality of ceramic ball to the use of bearing is demonstrated.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ174.1

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