SWING TRANSMISSION (53R3)
of the slewing ring, Therefore, the upper will swing when
hydraulic oil is supplied to the swing motor.
The disc brake is connected directly to the input shaft,
which includes the primary sun gear, and is a spring set-
Swing transmission 53R3 contains a double planetary gear
hydraulically released brake. The brake is released when
reduction, driven by a separate motor, and an integral
pressure is applied to the brake port. This pressure causes
the brake piston to move away from the brake discs, al-
lowing the discs to turn freely. When the pressure is vented
The hydraulic motor drives the sun gear of the primary
from the brake chamber, the brake springs move the brake
planetary reduction. The output of the primary reduction is
piston into contact with the brake discs. This clamps the
transmitted to the sun gear of the final planetary reduction.
brake discs between the housing and brake piston, thereby
The output of the final planetary reduction is transmitted
preventing the planetary reductions from turning.
directly to the swing pinion, which is mated to the ring gear
Figure 6D-1. Swing Transmission (53R3)