By Sinopec Online Technical Team
Introduction
Gearboxes in industrial plants, marine systems, and heavy transport operate under high load and sometimes shock. The lubricant must maintain a continuous film, manage heat, and resist oxidation. Sinopec gear oils are engineered for long-term protection, reduced downtime, and efficient operation in these conditions.
What a gear oil must achieve
- Maintain a load-bearing film under full-film and mixed-film conditions.
- Provide extreme-pressure protection to limit scuffing and micropitting during overload.
- Offer thermal and oxidation stability to minimise varnish and sludge.
- Deliver corrosion and rust protection in humid or water-prone environments.
- Exhibit rapid demulsification so free water separates and can be drained.
Choosing viscosity and base performance
Viscosity is specified by ISO VG and must fit load, speed, and temperature. Higher viscosity supports film thickness for slow or heavily loaded drives; lower grades cut churning losses at higher speeds. In variable climates, select a formulation with strong viscosity–temperature behaviour to avoid thick start-ups and thin running.
Common failure modes and how to prevent them
- Micropitting and scuffing: Use the maker’s specified service level and ensure adequate viscosity. Keep operating temperature within design limits.
- Oxidation and sludge: Choose a high-stability formulation and confirm intervals with oil analysis.
- Water contamination: Maintain breathers and seals. Drain free water promptly.
- Foaming and air entrainment: Verify air release and foam control. Fix poor tank design and replace clogged filters.
Base oils and additive chemistry
- EP additives (often sulphur–phosphorus or borate) protect tooth surfaces under boundary conditions.
- Antioxidants control viscosity rise and deposit formation at temperature.
- Rust inhibitors and corrosion inhibitors protect ferrous and yellow metals as specified.
- Demulsifiers improve water release and filter life.
- Antifoam agents stabilise film and reduce cavitation risk.
Maintenance that cuts downtime
- Sample at steady operating temperature. Track viscosity, wear metals, and particle counts.
- Keep breathers clean and fill points sealed. Store bulk oil under cover.
- Confirm compatibility when changing families; flush only when the maker instructs it.
Where to buy
Browse the live collections on Sinopec Online:
Cross-references
For base stock background and formulation context, see the Technical Insights series (site internal):
- Base Oil Market Report – October 2025
- Group I vs Group II Base Oils: Key Differences and Applications
- Group II vs Group III Base Oils: Performance and Formulation Insights
- Brightstock and Heavy Neutral Oils: Role in Modern Lubricant Blends
References
Published by Sinopec Online Technical Team
