Finding the center of the coupling is an important part of the overhaul work of the rotating equipment. If the correct method is not correct or the results found are not accurate, it will cause the vibration value of the rotating equipment to exceed the standard and seriously threaten the normal operation of the rotating equipment. It is a high-speed device and the data requirements for coupling alignment are extremely strict. Now we will elaborate on the problem of aligning rotating equipment couplings.
2 Coupling find center principle and analysis
There are different kinds of methods for finding the center of the coupling. According to the installation position of rotating equipment, it can be divided into horizontal and vertical types, of which horizontal type is more common; the simple type of correcting can be divided into simple correcting and system correcting. The former finds out rougher results. The results obtained are ideal. No matter how they are classified, their principles and analysis methods are the same.
2.1 Couplings to find the center
The purpose of finding the center is to make the centerline of a rotor shaft a continuation of the centerline of the other rotor shaft. Because the shafts of the two rotors are connected by couplings, the centerlines of the two rotors must be a continuous curve as long as the centerline of the two pairs of wheels of the coupling is continuous. To make the center of the two pairs of wheels of the coupling continuous, the following two conditions must be satisfied: (1) To make the centers of two pairs of wheels coincide, that is, to make the outer circles of the two pairs of wheels coincide; (2) The joint faces (end faces) of the two pairs of wheels are parallel (the two center lines are parallel).
As shown in Figure 1-1, if a1=a2=a3=a4, it means that the two pairs of wheels are parallel; if h1=h2=h3=h4, it means that the two pairs of wheels are concentric. At the same time satisfying the above two conditions, the centerline of the two axes is a continuation curve. If the measured values ​​are not equal, you need to adjust the ground to meet the above two conditions.
2.2 Coupling alignment status analysis
If the relative positions of the two pairs of couplings of the coupling do not satisfy the above two conditions, there are two states: two pairs of wheels open and two pairs of wheels open. Two of the pairs of wheel openings are divided into two types: motor-side pair wheel height and motor-side pair wheel-lower. The two pairs of wheel lower mouths are divided into motor-side pair wheel height and motor-side pair wheel low. The status classification of the two pairs of wheels relative position and the corresponding state diagram 1 --- 2.
2.3 Coupling counter calculation
The theoretical basis for the coupling calculation for the wheel alignment is the triangle similarity principle. The use of two right-angled triangles is similar to obtain the relationship between the quantity required and the known quantity, so that the specific value sought can be calculated. The following example uses state one as an example.
Analysis: The position of the motor side-to-wheel is adjusted on the basis of the turning-side wheel, so that the mutual positions of the two pairs of wheels meet the requirements.
Calculation: Let the diameter of the wheel be D, the distance between the motor-side x-bearing foot and the opposite wheel is l1, the distance between the motor-side y-bearing foot and its opposite wheel should be l, a: the motor-side pair of wheels should be opposite to the transfer-side pair of wheels. The opening degree, h: The height difference between the two pairs of wheels. According to the principle of triangle similarity:
RtΔAOAˊ∽RtΔAˊOˊE, then =
Δx=
;
RtΔACB∽RtΔAˊCˊBˊ, then =
, ie Δy=
;
And because the motor is on the side of the wheel to the wheel height h, the total adjustment of the foot gasket at both ends of the motor is:
x bearing foot gasket total adjustment: Δx-h = -h
y bearing foot gasket total adjustment: Δy-h= = ;-h
Similarly, the total adjustment amount of the foot gaskets at both ends of the motor in state 2, state 3, and state 4 can be found. The four status summary tables are shown in the following table.
From the above calculations, we can conclude the basic steps for the alignment of the coupling to the wheel:
(1) Measure the radial shake of the turning machine side and the axial scooping value;
(2), based on the measured data to draw a summary of the wheel deviation;
(3) Drawing the state diagram of the opposite side of the wheel from the wheel misalignment diagram;
(4) Calculate the adjustment amount of the foot gasket according to the state diagram;
(5), on-site adjustments.
2.4 Examples
Known: As shown in Figure 1-3, Figure 1-4, to find the total adjustment of the motor bearing two foot gasket.
answer:
(1) According to the data diagram of Figures 1-4, draw the total deviation deviation map shown in Figure 1-5;
(2), from the round of deviation summary drawing, as shown in Figure 1 - 6 and Figure 1 - 7 shown on the round state diagram;
(3) From the state diagrams of Figures 1-6 and 1-7, we can see that the upper and lower wheels of the wheel are up and the motor-side pair of wheels is higher than the turn-to-side pair of wheels. The right and left sides of the wheel are the lower opening and the motor is facing the wheel. Lower than the turning side to the wheel.
based on the above analysis,
(1) Calculating the amount of adjustment of the feet in the vertical direction:
x Bearing foot gasket total adjustment: Δx-h= -h=
-0.03=0.07mm;
y bearing foot gasket total adjustment: Δy-h= -h=
-0.03=0.27mm.
(2) Calculation of the amount of adjustment of the feet in the left and right direction:
x Bearing foot gasket total adjustment: -Δx+h=- -h=-
+0.07=-0.05mm;
y bearing foot gasket total adjustment: -Δy+h=- -h=-
+0.07=-0.29mm.
To sum up, we should add 0.07mm to the up and down direction of the x-bearing footbath, and 0.27mm on the up and down direction of the y-bearing footbath.
The x-bearing foot washer should move 0.05mm to the right in the left-right direction, and the y-bearing foot washer should be 0.29mm to the right in the up-down direction.