Planetary Gear Trains
WARNING: This page is about a different car, the 2019 Jaguar XJ and 2018 Jaguar XJ. However, it is still accessible from the selected car via links, so may be relevant.
The eight forward gears and the reverse gear are produced by a combination of four simple planetary gear sets, three clutches and two brakes. The front two gear sets share a common sun gear. Power is output always through the planetary carrier of the fourth gearset.
Five shift elements comprising three clutches and two brakes, are responsible for all eight forward and reverse gears. High efficiency is achieved by the use of only two shift elements disengaged in each gear which reduces drag and so increases the efficiency.
Planetary Gear Set 1
The planetary gear set 1 comprises:
- Sunwheel - shared by gear set 1 and 2
- Four planetary gears
- Planetary gear carrier (spider)
- Ring gear.
Planetary Gear Sets 2 and 3
The planetary gear sets 2 and 3 comprise:
- Sunwheel - shared by gear set 1 and 2
- Separate Sunwheel for Gearset 3
- Three planetary gears per gear set
- Planetary gear carrier (spider) per gear set
- Ring gear per gear set.
| Item | Description |
|---|---|
| 1 | Planetary gears - gear set 1 |
| 2 | Ring gear - gear set 1 |
| 3 | Planetary gear carrier (spider) |
| 4 | Planetary gears - gear set 2 |
| 5 | Ring gear - gear set 2 |
| 6 | Planetary gears - gear set 3 |
| 7 | Ring gear - gear set 3 |
| 8 | Sun wheel - gear set 3 |
| 9 | Sun wheel - joint gear sets 1 and 2 |
Planetary Gear Set 4
The planetary gear set 4 comprises:
- Sunwheel
- Four planetary gears
- Planetary gear carrier (spider) - output shaft
- Ring gear.
| Item | Description |
|---|---|
| 1 | Ring gear |
| 2 | Planetary gears |
| 3 | Output shaft/gear carrier |
| 4 | Sun wheel |