Maintenance Tips for the Gearbox of Twin Screw Extruder

In the daily production of twin screw extruders, necessary maintenance work needs to be carried out on the gearbox, and its basic contents are as follows:

 

Maintenance of gearbox

The gearbox of the twin screw extruder host should be well ventilated, and the working environment temperature should be within the range of 5-35 ℃. Regularly check the oil level of the gear lubricating oil inside the box to ensure that all transmission parts inside the box are well lubricated. Pay attention to regularly checking the bearing parts of the box, and the oil temperature in the transmission box should not exceed 70 ℃ during operation. The newly put into use gearbox needs to be replaced with lubricating oil after 250 hours of operation, and the oil change time in the future depends on the state of the oil. It is recommended to replace it after 4000-8000 hours of operation or once a year.

 

The gearbox needs to undergo regular maintenance and inspection once a year, with the following tasks:

a. Remove the gearbox cover and check the wear and meshing condition of the working surfaces of each transmission reduction gear. If there are burrs or shallow pits on the meshing surfaces, they can be polished smooth with an oil stone; Gears with severe wear should be prepared to purchase accessories for replacement during the next maintenance.

b. Check the wear of each bearing. First, clean the bearings and check whether there are cracks on the inner and outer sleeves; Observe the noise level and radial clearance during idle operation. If no problems are found, add some lubricating grease to continue using.

c. Check if the lubricating oil inside the box is clean. If there are impurities or metal powder mixed in the oil, filter and remove impurities before replenishing the lubricating oil.

d. After cleaning and inspecting the parts inside the box, install the box cover; After adding sufficient lubricating grease to each bearing area, replace it with a new oil seal and tighten the bearing cover. 

e. Clean the outside of the gear box and keep the equipment clean.

 

Principles for replacing parts in the gearbox

If there are deep wear pits on the involute meshing surface of a gear, the noise during operation and rotation is large and irregular, and there is often impact vibration, this type of gear should be replaced. The inner or outer sleeve of the ball bearing has cracks, the ball rack is damaged, the radial clearance of the inner sleeve is large, and the rotating noise of the outer sleeve bearing is high. After cleaning the rolling bearing, if one of the above damage phenomena is found, the rolling bearing should be replaced. Precautions for replacing and installing gears and bearings: Before installation, the gears and bearings should be cleaned and trimmed to remove burrs. The dimensions of the replacement gear hole, assembly shaft, key, and keyway should meet the matching tolerance requirements specified in the drawing. The replacement rolling bearing should have the same model as the original bearing.