Importance of pump alignment
The rotation centers of the two shafts connected by the coupling of pump and motor shall be strictly concentric, and the coupling must be accurately aligned and centered during installation, otherwise it will cause great stress on the coupling, and will seriously affect the normal operation of the shaft, bearing and other parts on the shaft, and even cause vibration or damage to the whole machine and foundation.
herefore, the pump and motor coupling alignment is one of the most important aspects of the installation and maintenance process.
II. Analysis of coupling alignment deviation
When installing a new pump, the verticality between the coupling end face and the axis can not be checked, but when installing an old pump, be sure to check carefully, and adjust the verticality when it is not vertical. In general, there are four possible situations.
1), S1=S2, a1=a2 The end faces of the two half-coupling wheels are in the correct position of both parallel and concentric, and the two axes must be located on a straight line.
2), S1=S2, a1≠a2 The end faces of the two semi-coupling wheels are parallel but the axes are not concentric. At this time, there is a parallel radial displacement e=(a2-a1)/2 between the two axes.
3), S1≠S2, a1=a2 Although the end faces of the two semi-coupling wheels are concentric, they are not parallel, and there is an angular displacement α between the two axes.
4), S1≠S2, a1≠a2 The end faces of the two half-coupling wheels are neither concentric nor parallel, and there is both radial displacement e and angular displacement α between the two axes.
The coupling in the first case is the ideal state we need to strive to achieve in the middle, while the other three states are not correct and need to be adjusted to achieve the first case.
When installing the equipment, first install the driven motor (that is, the pump head often said), so that its axis is in a horizontal position, and then install the main motor (that is, the motor often said), so only need to adjust the motor to find the timing, that is, in the motor under the foot of the method to adjust the gasket.
find the timing measurement adjustment method
The following mainly introduces two measurement adjustment methods commonly used in the maintenance process, which can be divided into:
1), the use of knife-shaped ruler and feeler gauge measurement of the coupling is not concentric and the use of wedge clearance rail or feeler gauge measurement of the coupling end surface is not parallel, this method is suitable for elastic connection of low speed, accuracy requirements are not high equipment.
2), using dial indicator and meter stand or special alignment tools (such as laser alignment corrector) to measure the two couplings are not concentric and not parallel, this method is suitable for high speed, rigid connection and high precision rotating equipment.
Note:
1) When aligning with feeler gauge and knife ruler, the radial end surface of the coupling should be flat, smooth, rust-free and burr-free.
2) In order to see the light of the knife-shaped ruler, it is best to use a flashlight.
3) For the final measurement value, the anchor bolts of the motor should be completely tightened without loosening.
4), with special tools to find the time, make the same mark, in order to avoid measurement data error increase, should be divided into 4-8 points, in order to obtain accurate data.
5) Making records is an important part of finding the right one.
There are the following ways to adjust the pad surface:
1), intuitive method (experience plus, minus pad method). Because in the maintenance, some pump alignment and not fully equipped with good conditions and tools, in the adjustment, the experience of the master will play a great role, each time add, reduce the pad should consider the tightness of the motor bolt and its margin.
2) Calculation method.
I. Original state
II. Raise Δh
III. Axis after adjustment
(1) Eliminate the height difference of the coupling first
The motor shaft should be lifted upwards by a spacer Δh, which is the front bearing A and the rear bearing B should be padded by Δh under the seat at the same time.
(2) Eliminate the opening of the coupling
In A, B bearing respectively add different thickness of the pad, B bearing pad should be added than A bearing after some.
Therefore, the total spacer thickness is: front mount A=Δh+AC; rear mount B=Δh+BD. (Among them, the calculation methods of AC and BD can be thought about how to obtain them from measurable data.)
Attachment: Deviation standard for centering of pump coupling (unit: mm)
End Distance of Pump Coupling
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