This oil pump assembly is manufactured to standardized specifications, delivering consistent performance for excavator operation scenarios across construction, mining and road maintenance worksites. It is constructed with high-strength cast iron casing to ensure long-term structural durability under frequent high-load mechanical operations, with excellent heat resistance to maintain stable oil supply efficiency even when the engine runs continuously at high temperatures. The precision-machined internal gears and seals minimize oil leakage risks while maintaining flow integrity, effectively blocking external debris from entering the internal oil circuit during operation to avoid damage to core engine components. Each unit undergoes strict pressure and flow testing before leaving the factory, matching factory standard installation dimensions for direct replacement without additional modification, reducing equipment downtime for maintenance.