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Talking about how to install the printing machine bearing

Release Time:2019-6-5 Click:45

The pressure should be directly applied to the end face of the ferrule, and the pressure should not be transmitted through the rolling element. The following methods are generally used for bearing installation:
The bearing outer ring is tightly matched with the bearing housing hole. When the inner ring and the shaft are loosely fitted, the bearing can be first pressed into the bearing housing hole. At this time, the outer diameter of the assembly sleeve should be slightly smaller than the diameter of the housing hole.
If the bearing ring and the shaft and the seat hole are tightly fitted, the inner ring and the outer ring should be pressed into the shaft and the seat hole at the same time, and the structure of the assembly sleeve should be able to simultaneously tighten the end faces of the inner ring and the outer ring of the bearing.
Heating fit
By heating the bearing or housing, the thermal fit is used to transform the tight fit into a loose fit installation method. It is a common and labor-saving installation method. This method is suitable for the installation of bearings with large interference. Before the hot assembly, put the bearing or the ferrule of the separable bearing into the fuel tank and heat it evenly at 80-100 °C, then take it out of the oil and load it on the shaft as soon as possible. After the cooling is prevented, the inner ring end face and the shoulder are not tightly attached, and the bearing can be axially fastened after cooling. When the outer ring of the bearing is tightly fitted with the bearing seat made of light metal, the hot-filling method of the heated bearing seat can avoid the abrasion of the mating surface.
When heating the bearing with the fuel tank, there should be a grid at a certain distance from the bottom of the box, as shown in Figure 2-7, or the bearing is hung with a hook. The bearing cannot be placed on the bottom of the box to prevent the sinking of impurities into the bearing or uneven. Heating, there must be a thermometer in the fuel tank, strictly control the oil temperature should not exceed 100 °C, to prevent tempering effect, so that the hardness of the ferrule is reduced.
About the installation of thrust bearings
The full complement of the thrust bearing and the shaft is generally a transition fit. The fit between the race and the bearing bore is generally a clearance fit. Therefore, the bearing is easier to install. The shaft spring of the two-way thrust bearing should be fixed on the shaft to prevent relative Rotate on the shaft.
The mounting method of the bearing is generally the case where the shaft rotates. Therefore, the cooperation between the inner ring and the shaft is a win-win cooperation, and the cooperation between the outer ring of the bearing and the bearing chamber is a clearance fit.
1) Bearing preparation
Since the bearings are rust-proofed and packaged, do not open the package until installation.
In addition, the anti-rust oil coated on the bearing has good lubricating properties, and can be used directly for bearings for general purpose or for bearings filled with grease without cleaning. However, for instrument bearings or bearings for high-speed rotation, the cleaning oil should be washed with a clean cleaning oil. The bearing is prone to rust and cannot be placed for a long time.
2) Inspection of the shaft and the casing
Clean the bearing and the casing to confirm the burrs left by scratches or machining. There must be no abrasive (SiC, Al2O3, etc.) sand or chips in the outer casing.
Secondly, check whether the size, shape and processing quality of the shaft and the casing are in accordance with the drawings.
Before installing the bearing, apply mechanical oil to each mating surface of the tested shaft and the outer casing.
Since the shaft is generally rotated, the inner ring and the outer ring can respectively adopt an interference fit and a clearance fit, and when the outer ring rotates, the outer ring adopts an interference fit.
(1) Press-in installation
Push-in installation generally uses a press, and bolts and nuts can also be used. When necessary, the hammer can be used.
(2) Hot sleeve installation
The hot-sleeve method of heating the bearing in the oil to expand it and then mounting it on the shaft can prevent the bearing from being subjected to unnecessary external force and complete the installation work in a short time.
Heating precautions:
1) Do not heat more than 100 degrees Celsius.
2) Do not allow the bearing to contact the bottom of the oil sump.
In addition, the hot-sleeve installation can also use an induction heating device to heat the bearing to expand it and then mount it on the shaft.