HYTRA axis

  1. HYTRA axis

HYTRA axis

AUTOMATIC STEERING & HYDRAULIC SUSPENSION

 

With the HYTRA® axle, Zunhammer has taken hydraulic suspension for axles to a whole new level. This further development of the proven PETRA pendulum axle combines hydraulic suspension with precise Ackermann steering in the steering trapezoid—for maximum driving stability, tight cornering, and a smooth ride. Linkage to the tractor for steering is completely eliminated: The LENA-TWIN forced steering system handles automatic control in all four available driving modes.

The PKE
in action

 

Since autumn 2025, the HYTRA® axle has been fitted as standard on the PROFI-Tanker PKE. It is available as an option for single-axle and tandem vehicles.

Smooth running

Hydraulically sprung, with adaptive control

Less vibration, more traction. The HYTRA system’s hydraulic suspension absorbs shocks and reduces pitching and rolling – even with large distribution booms and a full load.

Precise steering

Ackermann steering in the steering trapezium

Superb straight-line stability and tight turning circles. The track rod and steering cylinder are housed safely behind the centre tube of the axle. Safe in driveways, on slopes and at headlands.

Comfort & Protection

Less wear and tear, longer service life

Reduces the strain on both the driver and the machinery. The automatic steering system eliminates the need for manual intervention. Less tyre wear on the road, less damage to crops in the field.

Construction and structure
The HYTRA® axle with steering trapezium is a further development of the Zunhammer PETRA pendulum trapezium axle, combined with hydraulic suspension. The tie rod and steering cylinder are housed behind the central axle tube – this protects the sensitive components from damage during field use and makes maintenance work considerably easier. The steering knuckles, which are individually controlled for each wheel, ensure even weight distribution across all wheels and thus gentle ground contact.
Steering trapeze: Just like in a car
The tried-and-tested steering trapezium of the HYTRA axle works on the same principle as in any car or tractor: when cornering, the inside wheel turns at a steeper angle than the outside wheel. This reduces damage to the ground when turning on agricultural land and prevents tyre wear on the road. Standard trailer axles without a steering trapezium steer in parallel when cornering – this causes measurable damage to the ground and increased tyre wear.
LENA-TWIN Zwangslenkung
The LENA-TWIN adds an electronically controlled forced steering system to the HYTRA® axle. The steering lever with push rod to the tractor, which was previously fitted, is no longer required. Only the K80 ball, the electric lighting and the hydraulic load-sensing system need to be connected. The connecting linkages can no longer be damaged. The steering operates automatically via a gyroscope in four additional special driving modes – front and rear axle steerable, crab steering, on-road and automatic. Furthermore, the LENA-TWIN features a slope drift correction system. The steering angle is controlled accurately in real time without driver intervention.
Slope stability and work safety
A hydraulically suspended axle is particularly crucial when working with a wide working width: it minimises swaying movements in the field, prevents damage to the boom and enables faster working. The compensation provided by the hydraulic suspension in the HYTRA® axle prevents the vehicle from becoming unstable due to the sloshing of the liquid load. Active slope compensation mechanisms, such as tilt correction, can be implemented with this axle. The new axle noticeably improves driving safety in the field and on the road.
Environment and Soil
Thanks to the optimal weight distribution across all wheels, ground pressure is distributed evenly. The steering trapezium enables cornering optimised for tight turns without parallel steering – resulting in less damage to the crop, and providing long-term protection for agricultural land and crops at the headland. A low-mounted fuel tank and a lower centre of gravity further improve handling.

Technical data

Construction method Further development of the PETRA pendulum axle · steering trapezium · hydraulic suspension
Steering LENA-TWIN forced steering · gyroscope · 4 driving modes · no linkage to the tractor · K80 ball joint
Tyre options 800/60R32 · 750/60 R30.5 
Driving modes Forward · Reverse · Road · Automatic · Crawl · Hill hold
Availability Standard on the PROFI-Tanker PKE · Available as an option for single-axle and tandem vehicles · Standard on tridem vehicles from autumn 2025

Gallery

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