高速轴承的安装配合是应注意

高速轴承的安装配合是应注意
(1)由常温升至高温时的尺寸变化和硬度变化;

  (2)高速下离心力所引起的力系变化和形状变化。

  总之,在高速、高温的条件下,从配合和游隙的选择上要力求保持轴承的精度和工作性能,这是有难度的。

  为了保证轴承安装后的滚道变形小,过盈配合的过盈量不能取得太大,而高速下的离心力和高温下的热膨胀,或是抵销配合表面的法向压力。或是使配合面松弛,因此过盈量必须在考虑上述两种因素的前提下审慎地加以计算,在常温常速下有效的过盈量对于高速轴承 可能是无效的。

  如果计算结果这个矛盾太大(通常只有在超高速下才有这种情况),只有采取环下润滑法与静压润滑法并用的双重润滑措施,而这种方案有可能使轴承的dmn值突破300万的大关。

  在考虑高速轴承游隙时不但要考虑上述各项因素,而且要考虑轴的热伸长对游隙的影响,要求轴承在工作状态下,即在工作温度下有最佳的游隙,而这种游隙是在内、外圈球沟中心精确对位的状态下形成的。由于高速轴承力求降低相对滑动和内部摩擦,最好不要采用将内、外圈沿轴向相对错位的方法来调整球轴承的游隙。

  在考虑轴承的配合过盈量和游隙时,要注意到材料在高温下变得松软而容易变形的特点,以及多次由常温到高温的温度改变引起一定永久变形的可能性。

(1) when the temperature rose from ambient temperature changes in the size and hardness of Change;

(2) under high-speed centrifugal force caused by changes in the system of forces and shape of changes.

In short, high-speed, high-temperature conditions, and with clearance from the selection of want to keep a bearing on the accuracy and performance, this is difficult.

After installation in order to ensure the bearing deformation of the raceway small, the fit should not have made too much surplus capacity, and high-speed centrifugal force and under the high temperature thermal expansion, or set-off with the normal surface stress. Noodles with relaxation or so, it had surplus capacity must take into account the above two factors at the premise of carefully calculated at ambient temperature under constant speed over an effective amount of the surplus of high-speed bearings are probably invalid.

If this contradiction results too much (usually only at ultra-high-speed under such circumstances only), only under the Central Act and hydrostatic lubrication and lubrication method measures the dual lubrication, and this program has the potential to break through bearings dmn value of the three million mark.

In considering the clearance when the high-speed bearings to consider not only the factors mentioned above, but also to consider the hot-axis elongation of the impact of clearance requested a state of bearing in the workplace, that is, temperatures in the workplace has the best clearance, which Clearance species are included, the outer ring groove ball center position accuracy of the formation of the state. Search for lower speed because of the relative sliding bearings and internal friction, it is best not to be used, the outer ring relative position along the axial approach to adjust clearance of ball bearings.

In considering the bearing and fit with clearance, the material should be noted that at high temperature to become soft and easy to deformation characteristics, as well as many high temperature from ambient temperature to the temperature change caused by the possibility of permanent deformation must.

如何提高轴承安装时的实际配合精度

名词解释: 
  为了提高轴承安装时的实际配合精度,必须利用不使轴承变形的测量方法和测量工具,对轴承的内孔和外圆的配合表面尺寸进行实际的精密测量,可将有关内径和外径的测量项目全部予以测出,并且对测得数据作出全面分析,以此为据,精密配作轴与座孔的轴承安装部位的尺寸。在实际测量所配作的轴与座孔的相应尺寸和几何形

  为了提高轴承安装时的实际配合精度,必须利用不使轴承变形的测量方法和测量工具,对轴承的内孔和外圆的配合表面尺寸进行实际的精密测量,可将有关内径和外径的测量项目全部予以测出,并且对测得数据作出全面分析,以此为据,精密配作轴与座孔的轴承安装部位的尺寸。在实际测量所配作的轴与座孔的相应尺寸和几何形状时,应在与测量轴承时相同的温度条件下进行。

  为保证有较高的实际配合效果,轴和座孔与轴承相配的表面,其粗糙度应尽可能地小。

  在作上述测量时,应该在轴承的外圆和内孔上,以及轴和座孔的对应表面上,在靠近装配倒角的两侧,分别作出能示明最大偏差方向的两组标记,以便在实际装配时,使相配两方的最大偏差对准同一方位,这样在装配后,双方的偏差得以部分抵消。

  作出两组定向标志的目的,在于对偏差的补偿可以综合考虑,既使两端支承各自的旋转精度有所提高,又使两支承间的座孔和两端轴颈的同轴度误差得到部分消除。对配合表面实行表面强化措施,如喷砂处理,用直径略大的精密塞柱插塞一次内孔等,都有利于提高配合精度。