Hydraulic-pneumatic shift (HPS), function

B26.18-0005-06

1 Drive switch on the shift lever

2 GP drive valve

3 Relief valve

4 Compressed air reservoir

5 Compressed air filter

6 GV drive electro-pneumatic valve

7 GV drive cylinder

8 GP drive cylinder

9 GP drive valve

10 Switch for GP pilot lamp

11 Switch for reverse gear pilot lamp

12 Switch for GV pilot lamp

13 Neutral switch

B26.18-0006-06

1 Drive switch on the shift lever

2 GP drive valve

6 GV drive electro-pneumatic valve

7 GV drive cylinder

8 GP drive cylinder

9 GP drive valve

A Compressed air reservoir

Operation

The reservoir air feeds the valve on the drive switch of the shift lever (1), the GV drive valve (2) and the GP drive valve (9) on the shifter.

With the GP drive switch (1) positioned downwards, there is compressed air vent to the GV drive electro-pneumatic valve signal input (6). When the clutch pedal is pressed, the GV drive valve (2) allows air inlet to the GV drive electro-pneumatic valve (6) applying the GV drive cylinder (7).

When the drive switch is positioned upwards, the switch valve is closed and, thus there is no compressed air in the GV drive electro-pneumatic valve signal input (6). When the clutch pedal is pressed again, the GV drive valve (2) allows air inlet to the GV drive electro-pneumatic valve (6). As the valve has no compressed air in its signal input, the compressed air route is reversed and activates the other side of the GV drive cylinder (7), making it return.

To activate the GP cylinder (8) there is a control valve (9) in the shifter that according to the position of the shift lever it activates or deactivates the cylinder piston, activating or deactivating the GP. With the shift lever in the first H position, the valve releases compressed air to activate the GP and with the shift lever in the second H, the valve releases compressed air to the GP deactivation.