SEW reducer seal maintenance misunderstandings and solutions

Misunderstandings in the maintenance of SEW reducer seals: oil seals and gaskets are not replaced in a standardized manner, and oil leakage occurs repeatedly. The details are as follows:

Misunderstanding 1: If the oil seal is damaged, only replace the oil seal without checking the status of the journal.

Wrong approach: If you find oil leakage from the shaft head, directly remove the old oil seal, install the new oil seal and you are done. It may take a few days or a month or two before oil leakage occurs again.

Root cause: The long-term friction between the oil seal and the journal will cause scratches, wear, and rust on the surface of the journal. The lip of the new oil seal cannot closely fit the damaged journal, and it will naturally leak again.

Correct solution: Before replacing the oil seal, the journal surface must be carefully inspected. Use fine sandpaper to grind and polish minor scratches and rust; for severely worn journals with deep grooves, repair them by spraying or directly replace the shaft body; use a special pressure sleeve when installing the oil seal. Hammering is prohibited. The lip of the oil seal faces the inside of the box, and a small amount of grease is applied to the outside.

Misunderstanding 2: Apply sealant at will, too much or too little

Wrong approach: When oil leaks from the joint surface of the box, apply a thin layer of sealant, or apply a large amount of sealant for "insurance".

Hazards: The glue layer is too thin, the sealing is not tight, and oil still leaks; the glue layer is too thick, and excess glue falls off and enters the box, contaminating the lubricating oil, blocking the oil circuit, and causing wear of gears and bearings.

The correct solution: Thoroughly clean the old glue and impurities on the joint surface, and keep the surface dry and clean; apply a thin and continuous layer of sealant evenly along the joint surface, and control the width of the glue layer at 5-8mm; tighten the bolts in time after closing the box to avoid affecting the assembly after the glue solidifies.