A German heavy-equipment maintenance provider contacted EIM Bearing after repeated replacement-part failures on 30-ton excavators used for demanding breaking, ore-loading and wet-site work.
The reported symptoms included grinding noise, jerky rotation and difficulty turning under heavy load. Inspection also showed severe and uneven gear wear, spalling and broken teeth in the slewing gear system.
Engineering Review Focused on More Than the Replacement Bearing
The inquiry was received on September 7. Our sales and engineering teams reviewed the reported symptoms, application requirements and the relationship between the slewing bearing, pinion engagement, installation and lubrication.
The proposed bearing used an internal gear configuration matched to the customer’s original equipment requirements. The project specification called for 42CrMo alloy steel and defined gear heat treatment to support wear and fatigue resistance.
Installation Conditions Were Reviewed with the Bearing
Recurring slewing-system problems are not always caused by the replacement bearing alone. Gear backlash, bolt tightening, sealing, contamination and lubrication can all affect the performance of the installed assembly.
For this project, the review included gear-mesh clearance, cross-sequence bolt tightening to the specified requirements, cleaning of the gear cavity, dust-seal condition and a defined lubrication schedule.
Customer-Reported Result After Installation
The customer received the sea shipment on October 10 and performed an initial evaluation on the excavator.
According to the customer’s feedback, rotation was smooth without the previously reported grinding noise, and the earlier slippage was not observed during the initial slope and heavy-load checks.
The operating hours and observation period were not specified, so this result should be understood as the customer’s reported post-installation experience rather than a long-term life claim.
Project Summary
Product: Internally geared slewing bearings
Application: 30-ton excavator repair and maintenance
Destination: Germany
Material requirement: 42CrMo alloy steel with specified gear heat treatment
Review points: Gear engagement, backlash, fastening, sealing and lubrication
EIM manufactures standard and customized slewing ring bearings. For replacement projects, send the equipment model, bearing part number, dimensions or drawing through our Request a Quote page.
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Send the complete model designation or drawing, load conditions, speed, quantity and other critical requirements.
