Valtra introduces turning LHLINK front linkage

11/11/2007

However, the technical development of front linkages has been somewhat slow, focusing mainly on increasing lifting capacity. The degree of adjustability has been limited, as a result of which connecting implements has continued to be somewhat of a chore.

Valtra has responded to this situation by introducing a new generation of front linkage. Valtra’s innovative LHLINK front linkage attaches to the tractor’s frame by a vertical pivot, allowing the linkage to turn in the desired amount with the front wheels or even independently of the front wheels. In addition, the levelling of the lifting arms in relationship to each other can be adjusted vertically. The lifting capacity of the Valtra LHLINK front linkage is 3.5 tons.

These innovative solutions provide the lifting arms with a considerably higher degree of freedom, making it easier to attach implements while also increasing safety.

A front linkage that turns in relation to the front wheels is a great advantage when attaching front mowers and mowing combinations at the front and rear, for example. Valtra’s front linkage can turn a mower at its full width within a turning radius of 10 metres. This is possible because the implement applies Ackermann’s steering geometry, whereby a line drawn from the implement crosses a line drawn from rear wheels at the same point as lines drawn from the front wheels.

Four control modes are available for adjusting how the front linkage turns. In the first mode the front linkage turns fully independently of the front wheels. In the second mode the front linkage turns in relation to the front wheels, and the ratio between the turning angle of the front linkage and the steering angle of the wheels can be adjusted infinitely. The response in the middle of the adjustment range is 50%, so at a 35-degree steering angle the front linkage turns 17.5 degrees. At a response of 1:1 the turning angle of the front linkage is the same as that of the front wheels all the way up to 35 degrees, which is the maximum turning angle of the front linkage in either direction.

In the third mode the front linkage operates as above, but the central position of the front linkage can be varied in either direction. The fourth mode is designed especially for operating front and rear mower combinations, allowing a higher turning angle for the front linkage than for the wheels.

This range of adjustments eradicates underlap and offers a high quality of work. The same steering principle can also be applied to the operation of municipal brushing implements. Since the implement follows the turning radius, less lateral loads are put on the implement. The flexible front linkage does not restrict in any way the use of the PTO, as the universal joints are located around the pivot centre. 

The position of the lifting arms in relation to each other can be adjusted hydraulically, after which the position is locked hydraulically. There is no mechanical torsion bar between the lifting arms, which saves space. The cylinders are equipped with linear transmitting the position to the electronic control unit.

Valtra LHLINK front linkage has been developed together with the major Finnish parts supplier LH Lift Oy and Afcon Oy, an agricultural and forest technology R&D company. The front linkage has been designed for N Series tractors, and test marketing will begin in 2008.

Valtra LHLINK front linkage received the silver Innovation Award at the Agritechnica exhibition in Hanover, Germany in 2007.

Valtra Inc.

More information:
Hannu Niskanen, Valtra Brand Manager, +358 400 641 723, hannu.niskanen@valtra.com
Tapio Riipinen, toimitusjohtaja Afcon Oy, +358 40 5700 048, tapio.riipinen@afcon.fi

http://www.valtra.com/

 

Valtra Inc. develops, manufactures, markets and services Valtra tractors. Valtra is the leading tractor manufacturer in the Nordic countries and the second most popular brand in Latin America. Net sales in Europe, Africa and the Middle East (EAME) in 2006 amounted to 470 million euros and the number of employees to 950. Total production in Finland and Brazil amounted to 17,500 tractors. Valtra is a worldwide brand of AGCO Corporation.

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