FLANGE 7Y3728 - Caterpillar

Illustration 1 g00977432
Swing drive (1) Line to tank (2) Flushing oil inlet (3) Line from swing brake solenoid (brake release) (4) Planetary gear set (first stage)The swing drive is made up of the following components: top mounted swing motor, multiple disc brake, two planetary gear sets and output shaft with swing drive pinion. The swing motor operates in a closed control circuit.The pinion gear meshes with the swing gear. When the swing motor turns the pinion gear, the pinion rotates around the swing gear in order to rotate the upper structure on the swing bearing.The swing brake is a multiple disc brake and the brake is hydraulically released. The swing brake protects the upper structure against accidental rotation or drifting on a slope. The swing brake is maintenance free and the brake is cooled and lubricated by flushing oil (2) from the swing motor and the main control valve.When the swing brake is activated, the swing brake solenoid valve opens in order to release the hydraulic pressure that is holding the brake piston away from the brake discs in the swing brake. The spring force overcomes the hydraulic pressure and the swing brake is engaged.The output shaft of the swing motor is connected to first planetary gear set (4) of the swing drive. First planetary gear set (4) is connected to the second planetary gear set. The second planetary gear set is splined to the pinion gear. Each planetary gear set reduces the speed to the pinion gear. Each planetary gear set also increases the torque to the pinion gear. The torque output from the pinion gear is transmitted to the ring gear and the bearing.