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Analysis and Maintenance of Gear Shaft Damage

Pulished on Dec. 25, 2020



Analysis of the causes of gear shaft damage



(1) The Gear Shaft is bent and deformed. The deformation of the gear shaft is caused by excessive load and internal stress. Bending deformation has a greater impact on the work. Generally, the straightness error after bending should not be greater than 0.04 mm.


(2) Wear of the journal matched with the bearing. The interference between the bearing and the journal is generally about 0.01 to 0.05 mm. When the interference disappears, relative movement between the inner ring and the journal will increase the wear of the journal. However, since the sliding resistance between the inner ring of the bearing and the journal is greater than the rolling resistance, high-speed relative motion will not be formed between the two; and because the lubricant in the transmission is sufficient, when the inner ring and the journal form 0.02 to 0.04 A lubricating oil film is formed when a gap of mm is small, and its wear rate will be greatly slowed down. Therefore, during overhaul, only when there is a gap greater than 0.04 mm between the inner ring and the journal, should it be repaired.


(3) Wear of gear shaft splines. The gear shaft spline wear increases the radial clearance and the tooth side clearance. The allowable value of the side clearance of bulldozers and other construction machinery is about 1. 40 mm, and the allowable value of the side clearance of automobiles is about 0.30 mm.


Gear Shaft

Gear Shaft



Repair of gear shaft damage


(1) If the journal has slight scars, roughness, grooves or out of roundness, non-cylindricity, etc., it can be polished smoothly with No. 0 emery cloth or oil stone.


(2) If the journal has serious grooves, scars, roughness and wear, out of roundness and out-of-roundness exceed the allowable limit, it should be polished and trimmed on a grinder. General shafts with low quenching hardness or not quenched can be turned and sanded on a lathe. When the shaft journal is severely worn, it can be repaired by surfacing or inserting. Vibration surfacing, submerged arc welding, gas shielded welding, etc. can be used for surfacing welding; non-destructive testing should be carried out after welding.


(3) When the straightness error of the Heavy Duty Gear Shaft exceeds 0.04 mm, cold pressure correction or local flame heating correction can be performed. When calibrating, the amount of correction should be controlled, and the pressurized support position should be correct, especially to avoid stress concentration at the stepped shaft shoulder due to correction.


(4) Technical requirements after shaft repair. ①The shaft must not have defects such as cracks, damage, or scars. ②The metal surfacing on the shaft should be tight and free of pores, burns, incomplete penetration and hole slag. ③ The out-of-round and out-of-cylindricity of the journal shall not exceed the regulations.


If necessary, please contact the Gear Shaft Supplier


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