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| Illustration 1 | g00786752 |
Swing Drive (1) First stage planetary gear (2) Ring gear (3) Second stage planetary gear (4) Roller bearing (5) Roller bearing (6) Pinion shaft (7) Swing motor (8) Shaft (swing motor) (9) First stage sun gear (10) First stage carrier (11) Second stage carrier (12) Second stage sun gear (13) Housing (14) Bearing gear (swing bearing) | |
The swing drive consists of a series of planet gears. The planet gears reduce the rotating speed of swing motor (7). The swing motor is bolted on the swing drive. The swing drive is bolted to the upper structure. The teeth of pinion shaft (6) for the swing drive engage with bearing gear (14) of the swing bearing. Pinion shaft (6) provides motion by rotating around bearing gear (14). Bearing gear (14) 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 the following items: first stage sun gear (9), first stage planetary gears (1), ring gear (2) and first stage carrier (10). The second stage reduction consists of the following items: second stage sun gear (12), second stage planetary gears (3), ring gear (2) and second stage carrier (11) .
- The second group functions as the drive for reduced motor speed output. The second group consists of pinion shaft (6), roller bearings (4) and roller bearings (5). Pinion shaft (6) is supported by roller bearings (4) and (5) in housing (13) .
The planetary reduction group reduces the swing speed by the ratio of the number of ring gear teeth over the number of sun gear teeth. The compact swing drive incorporates the sun gear in the ring gear housing in order to provide a greater reduction ratio.
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| Illustration 2 | g00766853 |
Rotation of the first stage planetary gear (1) First stage planetary gear (2) Ring gear (9) First stage sun gear (10) First stage carrier (15) Shaft (first stage planetary gear) | |
Swing motor output shaft (8) is splined to first stage sun gear (9). First stage planetary gears (1) of first stage carrier (10) are engaged with first stage sun gear (9). As shaft (8) rotates first stage sun gear (9) counterclockwise, first stage planetary gears (1) rotate clockwise on shafts (15) and drive moves counterclockwise around ring gear (2). Ring gear (2) is bolted to housing (13). Now, first stage carrier (10) rotates counterclockwise.
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| Illustration 3 | g00766854 |
Swing Drive (Sectional) (1) First stage planetary gear (2) Ring gear (3) Second stage planetary gear (4) Roller bearing (5) Roller bearing (6) Pinion shaft (9) First stage sun gear (10) First stage carrier (11) Second stage carrier (12) Second stage sun gear (16) Inner circumference | |
Splines on inner circumference (16) of first stage carrier (10) engage with the splines on second stage sun gear (12). This causes second stage sun gear (12) to rotate counterclockwise. Now,second stage planetary gears (3) turn clockwise on the planetary shafts and the second stage planetary gears move counterclockwise around ring gear (2) in the same manner as the first stage. Second stage carrier (11) turns counterclockwise. The splines on the inner circumference of second stage carrier (11) engage with the splines of pinion shaft (6) and the second stage carrier causes pinion shaft (6) to rotate counterclockwise.
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| Illustration 4 | g00766855 |
Rotation of the pinion shaft (6) Pinion shaft (14) Bearing gear (swing bearing) (17) Location of moving pinion shaft | |
Pinion shaft (6) engages with bearing gear (14) on the inner circumference of the swing bearing. As pinion shaft (6) rotates counterclockwise, the pinion shaft moves clockwise around bearing gear (14). Bearing gear (14) is bolted to the lower structure. Since the drive is bolted to the upper structure, the upper structure rotates clockwise.