Power shuttle

A power shuttle is an additional unit used in transmissions. It is generally used in agricultural tractors. While the vehicle is moving forwards, the driver can pull a lever that makes it stop and go backwards at the same speed.

Power Shuttle also know under various trade names such as Power Reverser etc.Power shuttle feature is incorporated in the transmissions in two ways:
*1.Counter shaft Transmissions
*2.Full planetary (power shifts)
*3.CVT/IVT

1.Counter shaft transmissions

In this case generally forward reverse synchronizer is replaced by the multi plate friction clutches.Typically the multiplate clutches are arranged on the main shaft or on the counter shaft.The forward reverse section of the gear box is generally located in the forward section of the gear box.It is placed as close to the engine as possible.This is beneficial to the forward reverse control elements as they are not subjected to the high relative torques.The challenge involved in providing this feature in the existing transmissions is that complex arrangement of shafts.This problem arises due to the limitation of centre distance between the two shafts and fixed axial dimensions due to the vehicle size limitations.

2.Full Planetary(power shift)

In this type of transmissions the planetary action is used for providing forward or reverse action to the gear box.

3.CVT/IVT

Here the automatic nature of the gear box takes care of the direction change by either engaging planetary sets or by engaging multi plate clutches or by some other means.Features of power shuttle transmissions.Power shuttle transmissions were invented for mining and earth moving applications.The needs in the areas were:
#Quick shuttle response
#Left hand shuttle lever(so that right hand is free for loader joystick)
#Reducing driver fatigue.

References

* http://www.landini.com/pdf/05_RX2_PLT_8P.pdf