In heavy equipment, crowned tooth gear couplings are widely adopted for their high load capacity and strong misalignment compensation. After decades of technical accumulation, China has built a complete product system covering design, machining and inspection, gradually narrowing the gap with advanced foreign products. European couplings are represented by Germany's KTR, Flender, Renold and Voith, following the DIN/ISO system. European products are mature in sealing, lubrication and anti-corrosion, with high modularity and integration. Compared with domestic GICL series, European designs excel at integrated coupling with gearboxes and brake discs, performing stably under continuous operation. Sealing and lubrication are critical to coupling life. Domestic GICL commonly uses lip seals with lithium grease—simple and easy to maintain; European products often adopt labyrinth seals with centralized lubrication interfaces, better suited to long-running, low-maintenance automated lines. Understanding the differences between domestic and foreign crowned tooth couplings helps make better decisions in equipment matching and retrofit. It is recommended to perform selection calculations for the specific duty and consult professional manufacturers when necessary.