Seven Principles for Selecting Lubricating Grease for Bearings：

1. Environmental Conditions: When bearings operate in humid environments, corrosive gases, low temperatures, dust, or strong radiation, lubricating oil is prone to contamination and degradation. In such cases, lubricating oils with strong resistance to water, wear, corrosion, cold temperatures, and radiation should be selected. In areas subject to water splashes, emulsion sprays, humid air, or severe dust and debris, lubricating oils are generally not recommended; instead, lubricating greases should be used.

2. Bearing Precision: For rough friction surfaces, high-viscosity oils are generally suitable to withstand localized high pressures caused by poor contact. Conversely, for high-precision friction surfaces, low-viscosity lubricating grease should be selected to minimize unnecessary energy loss and temperature rise.

3. Operating Temperature: Temperature affects lubricant viscosity and lubrication effectiveness. At low temperatures, use lower-viscosity lubricants; at high temperatures, use high-viscosity lubricants or those with appropriate additives. For temperatures exceeding 200°C, consider solid lubricants. The viscosity of the selected lubricant should vary with ambient temperature. For example, when lubricating the same bearing, lower viscosity lubricants should be used in northern China or during winter compared to southern China or summer. When operating temperatures fluctuate frequently, lubricants with excellent viscosity-temperature characteristics should be selected. These lubricants exhibit minimal viscosity change with temperature variations, ensuring the oil film thickness remains stable within a specific range.

4. Operating Speed: Higher rotational speeds necessitate lower-viscosity lubricants to minimize friction resistance and excessive heat generation. Conversely, higher-viscosity lubricants are preferred at low speeds to enhance load-carrying capacity.

5. Motion Characteristics: Operations involving impact, vibration, frequent load/speed changes, starts, stops, reversals, or reciprocating/intermittent motion are unfavorable for oil film formation. Therefore, lubricating grease with higher viscosity should be selected. In some cases, grease or even solid lubricants may be preferable to ensure reliable lubrication.

6. Operating Load: The greater the load on rolling bearings, the higher the lubricant viscosity should be selected. The lubricant should also possess good oiliness and extreme pressure properties to prevent displacement from the friction pair or direct metal-to-metal contact. The smaller the radial clearance of rolling bearings and the higher the machining precision of friction surfaces, the lower the lubricating grease viscosity should be.

7. Bearing Hardness: When the friction surfaces of moving bearings have low hardness, high-viscosity grease should be selected with sufficient lubrication quantity. Conversely, grease viscosity can be reduced.

Shanghai Yisiou Trading Co., Ltd. is a powerful enterprise with a registered capital of 5 million RMB. Its product matrix includes ceramic bearings, hybrid ceramic bearings, solid oil bearings, tapered roller bearings, cylindrical roller bearings, etc. The products are widely used in aerospace, automotive and other fields, and have reliable performance under extreme conditions. The company is customer-centric and holds an important position in the industry.