SEAL 7Y4842 - Caterpillar

Illustration 1 g00705346
Swing Drive (1) First stage carrier (2) First stage planetary gear (3) Second stage carrier (4) Ring gear (5) Second stage planetary gear (6) Roller bearing (7) Roller bearing (8) Pinion shaft (9) Swing motor (10) Shaft (swing motor) (11) First stage sun gear (12) Second stage sun gear (14) Housing (15) Gear bearing (swing bearing)Right and left swing drive are identical in construction and operation. The left swing drive is described as an example. The swing drive consists of a series of planetary gears. The planetary gears reduce the rotating speed of swing motor (9). The swing motor is bolted on the swing drive. The swing drive is bolted to the upper structure. The teeth of the swing drive output pinion shaft (8) engage with gear bearing (15) of the swing bearing. Pinion shaft (8) provides motion to the upper structure by rotating around gear bearing (15). Gear bearing (15) is attached to the lower structure. The swing drive is divided into the following two groups.
The first group functions as a double reduction of motor speed. The first stage reduction consists of first stage sun gear (11), first stage planetary gears (2), first stage carrier (1) and ring gear (4). The second stage reduction consists of second stage sun gear (12), second stage planetary gears (5), second stage carrier (3) and ring gear (4) .
The second group functions as the drive for reducing the speed of the motor. The second group consists of a pinion shaft (8) which is supported by roller bearings (6) and (7) which are located in housing (14) .The planetary reduction group reduces the swing speed. The sun gear turns at a slower speed than the ring gear. The compact swing drive with the sun gear which is incorporated in the ring gear housing provides a greater reduction ratio.
Illustration 2 g00304788
First StageRotation of Planetary Gear (1) First stage carrier (2) First stage planetary gear (4) Ring gear (11) First stage sun gear (16) Shaft (first stage planetary gear)Swing motor output shaft (10) is splined to first stage sun gear (11). First stage planetary gears (2) of first stage carrier (1) are meshed with first stage sun gear (11). Shaft (10) rotates first stage sun gear (11) counterclockwise. First stage planetary gears (2) rotate clockwise on shafts (16), which move counterclockwise around ring gear (4). Ring gear (4) is bolted to housing (14). First stage carrier (1) rotates counterclockwise.
Illustration 3 g00304789
Swing Drive (Partial View) (1) First stage carrier (2) First stage planetary gear (3) Second stage carrier (4) Ring gear (5) Second stage planetary gear (6) Roller bearing (7) Roller bearing (8) Pinion shaft (11) First stage sun gear (12) Second stage sun gear (17) Inner circumferenceSplines on inner circumference (17) of first stage carrier (1) mesh with the splines on second stage sun gear (12). This causes second stage sun gear (12) to rotate counterclockwise when the first stage carrier rotates. Second stage planetary gears (5) turn clockwise on shafts. Second stage planetary gears