The importance of centring a rotating machine
01 What is heart to heart?
Alignment is to check and adjust the operation center line of two connected devices so that they become a straight line.
02 The purpose of the heart
Eliminate the unnecessary stress between bearing radial and shaft phase, prolong bearing life and make the rotating shaft run normally.
Avoid the vibration caused by bad heart, reduce the vibration amount of mechanical components;
Avoid damage of bearing and shaft seal in advance;
Avoid premature wear of coupling;
Avoid energy loss (precise centering can save about 5%~10% of energy);
Extend the life of the equipment and its components.
In short, the purpose of proper alignment is to extend the operating life of the machine. According to the experimental statistics, the failure rate of the bearing decreases to the third power. For example, a doubling of misalignment leaves 1/8 of the bearing life left (23=2×2×2=8), a tripling of misalignment leaves 1/27 of the bearing life left (33=3×3×3=27), and so on.
Symptoms of heart disease
Early damage of bearing, shaft seal, coupling and rotating shaft;
Bearing in the axial and radial direction produces one or two times the frequency of the large vibration;
Bearing position has high temperature and even a large number of discharge of lubricating oil phenomenon;
The screw of foundation pile is loose.
Coupling clearance is too large or damaged;
There is a high temperature phenomenon and rubber and plastic coupling will have powder discharge;
High motor running current;
Bearing damage on the track has 180 degrees with internal and external symmetric wear phenomenon.
Precautions for early preparation of pivot center
Check the condition of base surface, fixing screw, adjusting screw and coupling;
Check the radial and axial movement or axial bending deformation of the rotating shaft;
Check the soft feet, including: poor processing or corrosion of the foot base, corrosion of the base, corrosion of the gasket, stress of the pipeline, etc., these items should be eliminated in advance before the center;
The installation and erection of centering tools should avoid looseness or flexure;
Use flat stainless steel gaskets as far as possible, if not pre-cut gaskets, cutting should avoid the appearance of rough edges;
After aligning, it is recommended to use a thick gasket when the height needs to be adjusted to a relatively high level. The total number of gaskets for each foot should not exceed four.
Definition of heart type
Good at heart;
Parallel deviation is not centered;
Symmetrical Angle deviation is not centered;
Asymmetrical Angle deviation is not centered;
The mixed formula is parallel plus the Angle deviation is not centered;
The floating type is not centered.
In general, what we often say is not centered is a mixture of parallel plus Angle deviation not centered.
