Installation and adjustment with high speed bearings

When the co-ordination and high speed bearings clearance due to the rapid bearing both high precision bearings according to requirements, but also according to the requirements of high temperature bearings, so consider the mating and clearance, to take into account the following points:
(1) changes in the size and hardness changes in temperature rose at a high temperature;
(2) High speed centrifugal force caused by the force system changes and shape changes.
In short, at high speed, high temperature conditions, with and clearance from the choice you want to strive to maintain the accuracy and performance of the bearing, which is difficult. In order to ensure the installation of the rear bearing raceway deformation is small, angular contact ball bearing interference fit the amount of interference can not achieve much, but heat and centrifugal force at high speed under high temperature expansion, surface or offset with normal pressure. Or the mating surface relaxation, and therefore the amount of
interference must be carefully applied in consideration of the above two factors premise In computing, at normal temperature and normal speed under effective amount of interference for high-speed bearings may be invalid.

The adjustment of high speed bearing

If the calculation results of contradiction is too large (usually have this situation only at the highest speed), only take double lubricating measures under ring lubrication method and static pressure lubrication method,which is likely to make the DMN value exceeded 3 million of the bearing.

  Considering the high speed bearing clearance  not only include the factors mentioned above, but also  the effect of thermal elongation axis on the clearance of the bearing. The requirements in the working state, which has the best clearance at operating temperature.

  This clearance formed under the condition of the inner ring and the outer ring of the  ball groove center aligned accurately. As thehigh precision bearings to reduce the relative sliding and internal friction, clearance of SKF 71900C/DB angular contact ball bearing had better not use relative displacement methods within the inner ring and the outer ring along the axial direction to adjust the ball bearing.

How to express the inner diameter of the bearing?

The face of the bearing inner ring on the periphery or the number seen right from the first and second digit is the inner diameter of the bearing, i.e. with the diameter of the shaft. Press the bearing bore size divided into the following methods:
1, codenamed digital since 04 till 99 only, each pair of numbers from right to come ride with five figures represent the two high precision bearings bore size. For example, two digits after the 204 bearing 04, an inner diameter of 04 × 5 = 20 (mm). This section numbers bearing is the most common, it represents the bearing diameter from 20 mm to 495 mm.
2, the inner diameter of 10 to 20 mm in all the bearings (except magneto bearing), which diameter is constant, expressed as follows:
3,1-9 mm (including 9 mm) of small bearings, has its special representation:
Right from the first digit indicates the actual size of the bearing bore,
Right from the second digit indicates the bearing diameter series;
Right from the third digit is O.
For example: There is a small 25 bearings - right from the first digit "5" indicates the bearing inner diameter of 5 mm, the second digit "2" indicates that the bearing is light series single row radial ball bearings, the third digit is " 0 "did not write. Another example: 1006 self aligning roller bearings, represents an inner diameter of 6 mm light series double row spherical ball bearings.
Magneto ball bearings from the right two digits represent the actual size of the inner diameter. As 6015 bearing, represents an inner diameter of 15 mm of magneto ball bearings.
4, bearing diameter is not an integer, is part of a non-standard bearings. In this case, said in an approximation bearing code, and the third from the right in the figures marked with the number 9. Such as the Beijing brand BJ212-road automobile clutch release bearings 688,911, the actual size of the bearing inner diameter = 52.388 mm, diameter = 84.5 mm, width = 20.7 mm. 688911 bearing from the right of the first, two numbers are 11, according to the provisions of its diameter size should be 11 × 5 = 55 mm, but the actual size of the spherical ball bearings

 inner diameter of 52.388 mm. So it takes approximately 55 mm for digital proud bearing diameter code.
5, bearing code figures represented by the following three points:
(1) Bearing in 500 mm diameter size to LIi, the denominator figure represents the actual size of the inner diameter of the molecule digital representation of its series, the type and structure of the method according to the general bearing and regulations. For example 71/900 bearing denominator digital representation of the bearing inner diameter of 900 mm, molecular digital representation for the special lightweight single row tapered roller bearings.
(2) Needle roller bearings do with fractional code, the denominator figure represents the inner diameter of the bearing. For example 943/25 bearing denominator represents the inner diameter of the bearing 25 is of 25 mm.
(3) When the miniature bearings do with fractional code, its denominator figures represent the actual size of the inner diameter of the bearing. Such as 1009 / 2.5) bearing the denominator 2.5, is the diameter of the bearing is 2.5 mm.

How many of miniature ball bearings paired parts for testing

Since the accuracy of precision miniature ball miniature ball bearings itself within 1μm, thus requiring its matching parts (shafts, housings, end caps, ring, etc.) have a high dimensional accuracy and shape accuracy, especially to control the accuracy of the mating surfaces of the bearing within the same level, which is crucial, but also the most easily overlooked.
You must also pay attention to precision miniature ball bearings to match parts if not meet the above requirements, often makes precision bearings error occurs several times larger than the original bearings after installation, even 10 times higher than the error, completely ceases precision bearings, because Matching mechanical error is often not simply superimposed on the high precision bearings error, but in a different multiples after amplification additions.
Miniature ball bearing dimensions determined in accordance with the requirements are not the same. Parameters are not the same, bearing in determining the size parameters, we start from multiple angles. Here we talk to everyone from all angles:
In many cases, miniature ball bearings bore size has been specifically defined by the structure of a machine or device. Whether working life, static load safety factor and whether the economy will meet the requirements, bearing the rest before the final selection of the size and structure, will be subject to the size of calculus. The calculation includes the actual load with its load miniature linear bearings

 capacity for comparison.
Miniature ball bearing static load refers to the rear bearing load is stationary (no relative movement between the inner and outer rings) or rotational speed is very low. In this case, the calculation and the rolling body raceways and an excess of factor of safety of plastic deformation. Most affected by dynamic load bearing inner and outer rings relative motion, check the size of calculus fatigue damage raceways and rolling elements of early safety factor.
In fact, miniature ball bearings and model parameters are also functional relationship with the intended use. We must pay attention to these issues.