Hourglass slewing drive engages five to eleven teeth at one time than usual. This increased tooth engagement gives the gearbox tremendous power and strength and the slewing drive much higher torque endurance and durability. These attributes make it the perfect choice for wind turbine as well as other high-torque, high-load applications. The hourglass slewing drive also allows you to get both load-holding and rotational torque from the same gearbox.