In order to facilitate the user's future use, attention must be paid to the method and method when installing the centrifugal induced draft fan to avoid equipment damage and adverse impact on the user. Let's see how to install it.
1. Install the bearing housing base and rotor set
The leveling of the bearing box base and rotor group is an important part of the fan installation. Because of the heavy workload and difficulty, there is a time-consuming and labor-intensive motor installation and alignment project. The analysis requirements of technical points in installation are as follows:
(1) Leveling in horizontal direction: first, adjust the levelness of the front and rear bearing boxes (measure the split of the bearing box with a frame level), and the radial horizontal deviation is less than 0.3/1000; Secondly, adjust the levelness of the axial horizontal deviation less than 0.2/1000 (use the frame level to measure the top surface of the front and rear bearing housing bearings);
(2) Left and right direction: use the middle line of the motor base to find the middle line of the left and right directions of the main shaft, and find the middle line of the front and rear bearing boxes (test whether the left and right clearance of the bearing ball is uniform by the flexibility of the main shaft rotation);
(3) After the rotor set is completed, use the locating hole and bracket on the bearing box to drill and hinge, and then enter the taper pin for positioning to prevent the accuracy of the bearing box and rotor set from being damaged.
2. Installing bearing cover
(1) Method: Measure the clearance or interference value between the bearing housing (after the cover and base are locked) cover and the top surface of the bearing outer ring with the lead pressing method. If the clearance value is too large, the gasket shall be placed on the top surface of the bearing outer ring for adjustment to meet the matching requirements; If the interference value is too large, the sealing gasket shall be placed on the split of the bearing box to meet the matching requirements. For the front bearing housing and bearing outer ring, 0.03~0.05mm shall be assembled, and for the rear bearing housing and bearing outer ring, 0~0.03mm shall be assembled.
(2) Key points: When adjusting the thickness of the split gasket of the bearing box of the centrifugal induced draft fan, the pre-tightening force of the bolt should also be considered to be lower than the pre-tightening force of the complete locking in the later stage, and the pre-tightening force of the sealant (hot glue) coated in the later stage of compaction. Generally speaking, the former and the latter are flat to a certain extent, so the factors of both are ignored.
3. Install the bearing housing end cover
The installation quality of the bearing box end cover of the centrifugal induced draft fan directly affects the use of lubricating oil in the bearing box. Poor installation will lead to interference and friction between the end cover and the main shaft, oil leakage from the bearing box shaft head and other faults. Therefore, the following points should be noted during installation:
(1) The position of the end cover oil return hole should be placed at the bottom to ensure that the oil penetrating into the end cover shaft end oil seal can flow back to the bearing box through the oil return hole in time to prevent the lubricating oil from leaking from the shaft seal end;
(2) The clearance between the end cap and the oil slinger is shown in Figure 1. Dimension value 1 shall be ≥ 2mm to prevent the oil ring from flowing directly to the shaft end; The value 2 is required to be>0 mm to prevent contact friction between the end cover and the oil ring;
(3) The clearance between the end cover flange surface and the bearing housing is measured by the lead pressing method, so that the clearance between the end cover and the bearing outer ring at the axial positioning point is 0.15~0.2mm. Therefore, the thermal expansion allowance of the bearing is retained to ensure the positioning of the bearing. The rear bearing box is a movable end (to ensure the free expansion displacement of the shaft after heating), so there is no positioning requirement for the outer ring of the bearing.
When installing the centrifugal induced draft fan, pay attention to the method to avoid affecting the normal use in the later stage. After installation, the equipment can be put into trial operation to see whether it can be used normally. If there is no problem, you can put into work.
