Maintenance contents of transmission mechanism in machining

Failure causes and maintenance methods of belt drive
1. Journal bending
Causes: the dynamic balance of the pulley is poor, the axial strength is low, and the loading and unloading are improper.
Solution: the belt pulley shall be dynamically balanced; Cold straightening of slender shaft and small shaft; The shaft is appropriately thickened.
2. Pulley hole or journal wear
Cause: the fit between wheel hole and journal is too loose.
Solution: when the wear is not large, boring the wheel hole, chrome plating or spraying the journal to ensure the design requirements; When the wheel hole is seriously worn, the wheel hole can be bored and matched, and the sleeve can be fixed with slotted screws, and the keyway in the sleeve can be reworked.
3. Pulley collapse
Cause: the wheel hole and the journal are too tight and cracked, or too loose and impacted.
Solution: weld, insert or replace the pulley.
4. Belt slip
Cause: the belt tension is insufficient, and the initial speed of the driving wheel is too high.
Solution: adjust the tensioning device; Replace the old belt; Add anti-skid agent on the belt surface to increase the friction.
5. Tape skipping or tape dropping
Causes: the belt is partially worn and damaged, and the center lines of the two belt wheels are skewed.
Solution: replace the new belt; Align the center lines of the two wheel rims.
 

 Damage characteristics and maintenance of chain drive
1. Wear of plate chain assembly
This damage is mainly characterized by the plate chain being stretched, shaking during operation, chain dropping or chain jamming. The solution is to adjust the center distance and tighten the chain; Adjust the tensioning wheel and tighten the chain; Remove a section of chain link; In case of serious chain dropping and jamming, it shall be removed and replaced to avoid aggravation of wear.
2. Tooth profile wear
The teeth tend to be sharp and thin, and the tooth tip is inclined to the direction of the chain force, which aggravates the wear of the chain. Solution: for moderate wear, the sprocket can be turned over for continued use; Some gear teeth are obviously worn and can be used in transposition; The sprocket with severe wear shall be replaced.
3. Sprocket surface deformation
When the sprocket rotates, the teeth are not on the same plane, resulting in chain dropping, chain biting or chain skipping. It can be solved by checking and leveling the sprocket surface on the flat plate.
4. Two wheel offset
Chain bite, sprocket and local wear of the chain are intensified. The solution is to check with the pull wire method on site and then adjust the sprocket position.

3、 Maintenance of gear transmission
1. Change gear fatigue wear, pitting and peeling
(1) Improper selection of gear material: re selection.
(2) Low hardness of gear teeth: heat treatment.
(3) Gear overload operation or uneven load distribution: ensure proper side clearance and contact spots.
2. Cracked or broken teeth
(1) Impacted or hard objects stuck in the gear teeth: carefully check and manually pull before driving
(2) Quenching crack: gear shall be subject to flaw detection
3. Indentation on the tooth surface
There are iron scraps and other impurities between the gear teeth during transmission: clean the oil tank and gear.
4. Gear wear during low-speed operation
The oil film is too thin: use high viscosity lubricating oil.
5. Gear wear during high-speed operation
Overload, poor lubrication or too small side clearance: adjust side clearance, reduce load and improve lubrication.
6. Tooth tip sharpening, tooth root bite, plastic deformation of teeth
(1) The center distance is too small and the meshing is poor: use the modified gear.
(2) Overload, oil cut-off, overheating, insufficient tooth hardness and strength: reduce the load, timely supply oil, and ensure the hardness and strength of the tooth surface.

7. Gluing
(1) Excessive load, gear overload transmission: reduce the load.
(2) Poor lubrication: improve lubrication.
(3) Rough tooth surface, low hardness and poor contact: improve tooth surface hardness and surface roughness.
8. The small wheel is greatly worn
(1) Large difference in the number of teeth: improve the hardness of the small wheel.
(2) Rotating speed: improve lubrication conditions.