Slewing drive consist of slewing ring, worm, casting housing and some standard components.In solar energy PV power generation system. Slewing drive work with the Dc planet gear motor or Exchange decelerating motors.In engineering machinery, slewing drive used hydraulic motor as driving system. Slewing drive, are mainly applied in crane, excavator, engineering machinery, sun-tracking system ect, especially widly used in the solar energy PV power generation system. Slewing drive have different types and specifications, according to the similar raceway diameter slewing drive have:WD-080, WD-0130, WD-0170, WD-0223, WD-0343, WD-0419, WD-0478, WD-0625 etc specification."WD"is the acronym of Worm and Drive. Which is foreign models tagging habit.In home, we usd the SE which is the acronym of Slewing and Enclose, the unit by inch(1 inch=25.4mm), it has:SE3, SE5, SE7, SE9, SE12, SE14, SE17, SE21, SE25ect.Both WD and SE have the same mounting diameter and performance parameter.