Three-row pole slewing ring has 3 seating seals,upper,lower and radial rollgangs.They are seperated and sustaining forces from different directions.The contact between rollers and rollgangs is line contact, they can bear great strength,thus are the ideal fittings for heavy machinery. They are usually applied to wheel cranes,reclaiming bucket excavators,ship cranes ,steel shipping operation platforms and large tonnage cranes. 　　
　　 The latest two production standards for three-row pole slewing ring are JB/T 10837-2008 and JB/T2300-1999 Slewing Ring.