A Middle Disc is the key to transferring torque between the sun gear and the ring gear. When the sun gear rotates, it drives the middle disc. The middle disc then drives the ring gear. This process of torque transfer is what allows the planetary gear train to multiply torque. The middle disc also provides a reaction surface for the sun gear and the ring gear. Attributes:• Reduces noise and vibration by smoothing out the rotation of the gears• Manufactured to precise specifications and is durable and reliableApplications:A Middle Disc distributes the load between the sun gear and the ring gear.