ターボチャージャー部品の点検と交換の判断 (2)
Inspection and Replacement Judgment of Turbocharger Parts (2)
6. Maintenance of oil seal plate
Check the oil seal plate for cracks, surface roughness and deformation. If damaged, it should be replaced.
7. Sealing ring
When the turbocharger is running, dry friction occurs between the sealing ring and the relevant moving parts, which will inevitably cause wear. If it is not disassembled, it can still be reliably sealed due to the mutual friction and cooperation. Therefore it needs to be replaced. After disassembly, the thickness of the seal ring can be measured to check for wear. Put a new seal ring into the groove, if the gap exceeds 0.23 mm, the oil seal sleeve should be scrapped. The retaining ring of the floating bearing is a vulnerable seal and needs to be replaced once disassembled.
8. Overhaul of air compressor impeller
The air compressor impeller consists of blades, hub, disc and wheel cover. When it rotates, the air is compressed under the action of centrifugal force and thrown to the edge of the working wheel, so that the kinetic energy of the air is increased, and the pressure, flow rate and temperature are increased. The air compressor impeller is cast with aluminum alloy and fixed on the rotor shaft with a nut. If the blade has cracks, cracks or scratches with the compressor casing, special dye solutions can be used to check the cracks.
9. Turbine impeller overhaul
The blade and disc of the turbine are cast into one body by a precise method, and the shape of the blade is generally parabolic or quadratic. Because the turbocharger actuator works under the impact of high temperature, high speed and corrosive gas, it is required to have high material strength, high temperature resistance and corrosion resistance, and is often cast in heat-resistant alloy steel. Generally, the turbine and rotor shaft are welded together. Check the seal ring groove for damage during inspection. Small grooves or scars are permitted, but deep grooves are not allowed. Grind with a fine emery cloth before new use. Check for nicks on turbine thrust shoulders; check for cracks on turbine wheel with specialty dye solution. If there is a crack on the turbine wheel, the entire assembly cannot be used.
10. Turbine shaft journal
After a period of operation, the surface of the rotating shaft will generally be discolored at high temperature, and the bearing parts will be polished. As long as the journal fitting clearance is within the specified range, and there are no obvious scratches and grooves, it can continue to be used.
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