Lubricant filling quantity of slewing bearing raceway

1. General filling principle

Recommended range: Normally the filling quantity is 30%-50% of the raceway space. This range can balance the lubrication effect and running resistance, avoiding too much to cause leakage or too little to cause wear of the slewing bearings.

2. Core influencing factors

Lubrication method:

Grease lubrication: commonly used high viscosity extreme pressure lithium grease, the filling amount is mostly 30%-50%.

Oil lubrication: need to be combined with the seal design, part of the system adopts circulating oil lubrication, the initial oil volume is determined by the system design.

Working conditions:

High load / low speed: appropriate increase to 50%, to ensure the oil film strength.

High speed/high temperature: can be slightly reduced (e.g. 30%) to reduce the heat of agitation, but need to be combined with high temperature resistant grease.

Sealing performance: multi-layer labyrinth seal can support higher filling amount (40%-50%), simple seal is recommended ≤ 30%.

3. Risks of over- and under-filling

Excessive (>60%): lead to leakage of seals under pressure, increased mixing resistance temperature rise of 10-20 ℃, energy consumption.

Insufficient (<20%): boundary lubrication state, wear rate may increase 3-5 times.

4. Factory test standards

The regular manufacturer determines the optimum oil quantity by means of simulation tests, e.g:

No-load running test: to check the initial lubrication distribution of the slewing bearings

24-hour leakage test: to verify the reliability of the sealing system

Temperature rise monitoring: to ensure thermal balance of the lubrication system

5. Maintenance recommendations

Initial Maintenance Interval: It is recommended to check and replenish the grease after 50 hours of operation.

Routine Maintenance: Replenish every 500 operating hours or 3 months with 15%-20% of the initial amount.

Extreme working conditions: Dusty environments require 30% shorter maintenance intervals, and low-temperature environments should be replaced with low-temperature grease (NLGI 0-1 grade).

Users are advised to use infrared camera to monitor the temperature distribution of the raceway on a regular basis. Abnormal temperature rise (e.g. localised over ambient temperature +50℃) may indicate abnormal lubrication.