FAQs

Naarva Stroke harvesters hydraulic

What are the hydraulic requirement for Naarva stroke harvesters?

The recommended hydraulic specifications are:
S23C 40 – 60 L/min and 170 – 200 bar
S35C 50 – 70 L/min and 180 – 210 bar

Feeding hose 1/2″. Return hose min 1/2″ but to avoid excessive back pressure, return hose of 3/4″ is recommended.

It is recommended that the Grapple CLOSE / OPEN function is controlled by 2 buttons. Pedal should be avoided.

How do hydraulics affect S35C tilt function?

On the S35C model, the tilt holding force is adjustable.
Adjustment instructions can be found in the operator manual.

How do hydraulics affect delimbing performance?

Delimbing force
Delimbing force is determined by the cylinder piston size and the oil pressure.
Refer to the technical table for calculated forces based on cylinder dimensions and pressure

Delimbing force in kN
Stroke cylinder piston diameter
Oil pressure40mm50mm
170 bar2132.7
180 bar22.234.7
190 bar23.436.6
200 bar24.738.5
210 bar25.940.4

 

Delimbing speed (forward stroke)
Within the specified delimbing diameter range: Higher oil flow results in faster forward stroke motion

Delimbing speed (return stroke)
During the return stroke, oil exits the cylinder:
– Excessive back pressure slows down the movement
– A sufficiently large return hose is essential to ensure efficient cylinder emptying and fast return speed

How do hydraulics affect sawing performance?

Sawing performance depends on several factors, including tree type. However, higher oil flow and pressure increase sawing speed and cutting power

How the hydraulics of the base machine influence harvester performance?

The performance of the harvester is directly affected by the hydraulic characteristics of the base machine:

  • Oil flow (L/min) determines the operating speed
  • Pressure (bar) determines the available force/power
  • Back pressure reduces the effective working force

For optimal performance, it is important to minimise back pressure. This is achieved by using a sufficiently large return line.