What are the reasons for overheating or noise in the bearing parts of gear reducers

Overheating or noise in the bearing area of gear reducers is a common fault signal during equipment operation, usually caused by lubrication, installation, component damage, or external factors. The following is a specific analysis of the reasons:

1、 Lubrication issues

Improper lubrication is the primary cause of bearing overheating and noise generation, with approximately 40% of bearing failures related to this.

Insufficient lubrication or dry friction: If the oil level of the lubricating oil (grease) is too low, the oil circuit is blocked, or the refueling cycle is too long, it will cause an ineffective lubricating oil film to form inside the bearing. The metal surface will directly contact and rub, producing high-frequency sharp whistling sounds and a large amount of heat.

Excessive lubricating oil (grease): Excessive lubricating grease will increase the stirring resistance during bearing operation, and also lead to temperature rise.

Incorrect or deteriorated oil selection: Lubricating oil with mismatched viscosity (too high or too low) or mismatched model was used, which cannot provide effective protection. In addition, lubricating oil will age, oxidize, and mix impurities (such as metal shavings, dust, and moisture) after long-term use, leading to a decrease in lubrication performance or even failure, exacerbating wear and noise.

2、 Improper installation and coordination

Incorrect installation can directly alter the internal stress and operational status of the bearing, leading to malfunctions.

Installation skewness or non concentricity: When installing bearings, tilting or poor alignment of the shaft system between the reducer, motor, and load equipment can cause additional eccentric stress on the bearings, resulting in irregular noise, vibration, and local overheating.

Improper fit tolerance: The tight or loose fit between the inner ring and shaft of the bearing, as well as between the outer ring and the bearing seat hole, can cause problems. Tight fitting can reduce or even eliminate bearing clearance, leading to frictional heating; If the coordination is too loose, it will produce collisions and roars.

Improper pre tightening force: For bearings that require pre tightening, excessive or insufficient pre tightening force can affect their normal operation, resulting in noise and temperature rise.

3、 The bearing itself is damaged

After long-term operation, the internal components of bearings may experience wear or fatigue damage.

Wear and fatigue: The ball bearings and inner and outer raceway of bearings may experience pitting, peeling, or wear due to long-term alternating stress, resulting in increased clearance. During operation, the rolling elements shake and collide within the raceway, producing a low, irregular buzzing sound or periodic clicking sound.

Damage to the cage: The fracture or deformation of the bearing cage can disrupt the normal arrangement of the rolling elements, causing severe vibration and noise.

Abnormal bearing clearance: Whether it is due to improper selection of the original clearance or increased working clearance caused by wear, it can cause vibration and noise.