|Tractor News > 2001|
How to Restore Your Farm Tractor
Valtra S series tractorsValtra - November 11, 2001
Valtra S Series has been designed to perform well in all work situations that farmers are expecting from high horsepower tractors. The current market is demanding more versatility, which will give a better return on machinery investment.
These requirements include:
The Valtra design concept allows the S Series to perform all these operations exceptionally well. The balanced design is for multi-purpose use. The forward mounted engine and fluid clutch are connected to the centre frame, which holds the hydraulic oil. This gives a very good weight distribution of 43% to the front and 57% to the rear, which enables these operations to be performed well.
Some competitors in this sector have been designed to perform well in just one of these operations, by doing this they have restricted their performance in the other areas.
The overall weight of less than 9 tons with full tanks is not excessive. Extra weight can be added when needed. The turning radius is small, with fenders that swivel on tight turns and they can be turned out of the way for access during servicing.
The S Series cab is mounted high for good visibility and control of implements. The 600 litre fuel capacity is sufficient for a full days work.
Looking into the future, these multipurpose characteristics of the S Series will also have a wide market appeal and be reflected in a higher resale value.
Engine Valtra uses its own well proven large capacity (8.4 litres) 645 series engine in the S Series. This engine shares many components with the 620 and 634 series engines such as heavy-duty cylinder heads with cast air inlets.
Valtra’s engines are purpose built for off road applications and are renowned for their long life and reliability. Features such as wet liners with centre support have helped this reputation.
In the S Series the electronic management control of high torque and power gives new efficiency and savings. For the operator the clearest advantage is the cruise/driving speed and pto/engine speed controls giving the possibility to maintain the required speed for a particular operation. With the advanced cruise control it is also possible to have a speed set for the main field operation and then a simple change to another speed for headland work.
The sloping bonnet is easy to open for servicing and to clean the radiators. (Pressurized air is available from the tractor). By means of removing separate side shields all engine components are accessible.
Transmission The transmission of the S Series is semi-powershift, which means it offers the fuel efficiency of a multi-step (10 speed ranges) mechanical transmission, the flexibility of a powershift and market standard top speed of 50kmh with full power shuttle flexibility. Smooth start-ups and gear changes are guaranteed by the turbine clutch. The large service free unit is the constant volume type, as in the Valtra 6000 models. It gives the possibility to control the start smoothly up to 1300 engine revs after which there is virtually direct drive. The turbine clutch is ideal for handling high power requirements in the field and also heavy trailers on the road. It also protects and reduces stress on the transmission, the implements and also the driver.
The hydraulic shuttle is similar to the unit on the HiTech tractors, which is well known for its smooth operation. The power control system selects the ideal engagement every time. As an example, in the manual mode the forward and reverse Delta Powershift gears can be easily programmed for quicker turn rounds on headlands.
The shuttle lever is also used to engage and release the parking brake. The parking brake will always be engaged when the engine is stopped. This function is similar to that in the HiTech range.
The powershift is also similar to the HiTech range with the choice of either manual control or two automatic modes. Auto 1 is programmed to get the best performance and economy from the tractor both in the field and on the road. Auto 2 can be programmed by the operator to match a specific work requirement or personal style of driving. The 6 plate drive brakes of the tractor are power assisted. With TwinTrac there are also two brake pedals on the rear of the cab.
In S Series the 4wd and differential locks can be set to work fully automatically according to the wheel slip and front wheel turning angle. With automatic control engaged there is no need for the driver to pay any attention to their operation.
The front axle can be selected as either rigid or with suspension. Because of the balanced frame of the S Series even with the rigid axle driving is comfortable and safe at any speed. With suspension a high traction is achieved in field conditions and the height can be adjusted, which is an additional advantage with front implements.
Hydraulics The S Series has electronic lift control to the front and rear linkage. The settings for the standard controls are made by the Tractor Terminal. The rear linkage has a lift capacity of 10 tons and the front linkage (when fitted) 7.5 tons. Wheel slip monitoring and control, where the rear linkage will lift when a preset wheel slip percentage is exceeded, is a standard feature.
The hydraulic oil is separate from the transmission oil and is located in the centre frame oil tank. Up to 80 litres is available for external use.
The hydraulic pump has a capacity of 147 litres/min. It is a radial pump with load sensing. The output, at the highest 34Kw on power beyond, can be used for 7 auxiliary valves that are fitted as standard. The first one of these is designed for hydraulic motor use with a capacity of up to 100 litre/min. All the other valves are 80 litres/min.
The flow to each valve can be individually adjusted as is the time the valve stays in operation (oil supply time). The settings are individual for both ports of each valve and the settings are made by the Tractor Terminal. This includes the possibility to close the valve in question, put it in constant flow or in the floating position, or give a special function to control the oil supply according to the drive speed. In addition not only the amount of flow but also the “ramp time”, which is the ability to progressively increase or decrease the flow can be set.
The tractor has seven valves and by means of the control system two of these valves can be selected and programmed either for use in the front or the rear. If front linkage is fitted there are quick couplers ready for these two valves. Also one valve can be used for tractor functions such as hydraulic pick-up hitch or levelling cylinder.
There are three slide switches in the arm rest for valves one to three and a joy stick for valves four and five (front and rear implements). On the side panel there are two slide switches for valves six and seven. Number six is used for the two tractor functions. Number seven, which has duplicate controls on the rear fenders, can be used for example when connecting a hydraulic top link or levelling control.
The combined settings for a particular implement operation can be stored in the memory for future use.
Driver’s Environment The cab of the Valtra S Series gives a totally new dimension to a large tractor driver’s environment. The spacious four post cab with flat floor is located high up, which gives the best possible all round visibility. Not only giving the best view of the implements but also for additional safety and a more relaxed feeling during long working days.
The tractor must stay effective twenty-four hours a day. That is why there is a modern working light system, with six roof mounted lights at both the front and the rear. The operator can select the light best suited for each job and save this setting in the memory by means of the Working Light Control. Once set only switch is then required.
When front mounted implements are used high mounted headlights are available for safe road operation. Also there are special lights to help access to the cab, working lights for areas close to the tractor to illuminate the front wheel area and also the pto and trailer hitch.
The wide outside mirrors can be adjusted from inside the cab to match both the size of the implement and driving conditions.
Automatic climate control takes care of the atmosphere in any conditions from the summer in the south to the Scandinavian winter in the north. Another important feature to improve the driver’s environment is pneumatic cab suspension.
The controls are also an important part of the cab design. To get the best performance from the tractor and the operator they must be easy to see and to reach with the most regularly used controls nearest to hand. Valtra has put these in the armrest. They include linkage control, five valve controls, cruise control, pto, 4wd, diff-lock and duplicated shuttle and powershift controls. Whatever the position of the seat, these controls are always at hand, even when using TwinTrac.
The Tractor Terminal and the Light Controller are on the side panel.
In the S Series all the control units are connected by a can-bus system. This allows the control units to work together to gain the best performance for the tractor rather than individually.
The Valtra concept incorporates all these features to provide a multipurpose high horsepower tractor with exceptional operator controls and environment. The combination of all these features will ensure an efficient, high performance tractor that is comfortable to operate and enjoyable to drive.