Gesadur underrollers

Rollers made of GESADUR® DN

Reduce running noises, increase number of revolutions

Underrollers made of laminates or steel show high wear. If the machine is at a standstill for a longer period of time, the underrollers can break or become permanently deformed. This results in high running noise and vibrations - the machine works inefficiently!

The memory effect works with GESADUR® DN: If machines start up again after a longer standstill, the track rollers regain their original shape. This means that track rollers made of GESADUR® DN do not flatten permanently! This means that the number of revolutions of the machine can be increased with GESADUR® DN, while at the same time the running noise decreases.

Delivery forms

  • pre-turned with allowance on all sides, i.e. with an allowance of 2 mm on the outer Ø, inner Ø and width
  • finish machined, outer-Ø with allowance
  • completely finished with steel bush and/or steel shaft, outer-Ø turned with diamond, concentricity max. 0,01 mm
  • sawn to size, with or without addition
Sachsenroeder underrollers

New design of underrollers

The dimensions of the underrollers are calculated according to the Stribeck rolling press curve. Please refer to our separate calculation brochure. When manufacturing underrollers, it is irrelevant in terms of price whether the bore has a small or large internal diameter. We therefore recommend a small bore with a steel bush of a low wall thickness.

The specific gravity of GESADUR® DN is 1.37 g/cm³, as opposed to approx. 7.8 g/cm³ of steel. This saves weight. Cost savings also come from the lower price of a smaller steel bushing. For the steel bushing we recommend normalized steel. Gray cast iron is also used, but this can shrink over time, and then an interference fit is no longer guaranteed.

To achieve the best concentricity accuracy, the following procedure should be followed: The steel bushing is manufactured with an extra length of 20 mm (see diagram 01). After pressing in the steel bushing and pinning it with the 3 clamping sleeves, the roll is clamped at the extra length on the lathe from outside.

Thus, outer and inner diameters can be turned in one clamping. The extra length is turned in a separate operation, the concentricity accuracy is max. 0.01 mm. We recommend turning the outside diameter (the running surface) with a natural diamond, because the best accuracy and running surface is achieved with the natural diamond. Normal carbide tools could wear out during precision machining. The roller would then be slightly conical.

Maintenance and cleaning

Due to dusty working areas, dirt particles can accumulate on the roller surfaces. As a result, the rollers are only loaded and overloaded selectively, so that they can finally burn. For cleaning the tread surfaces we recommend our wheel cleaning device and wheel cleaning agent GESACLEAN.

Moulds

Please note that we press GESADUR® DN exclusively in piston molds. Below you will find the maximum finished diameters that we can turn from our individual press forms. For the tread width, we have indicated the maximum widths of the corresponding press forms.

Maximum production diameters
207 234 262 287 322 362 407 412 492 552 632 707 1012
Maximum width
130 130 150 150 150 170 200 200 200 280 280 280 370

Technical specifications

Compressive strength 300 N/mm2
Flexural Strength 81 N/mm2
Tensile strength transverse to the pressing direction 45 N/mm2
Young's modulus 7 - 10 GPa
Specific gravity 1.37 g/cm3
Water absorption DIN EN ISO 62 47 mg
Heat deflection temperature (HDT) DIN 75-1-3-2004 130°C
Dielectric strength, IEC 60243-P1 (4 mm plate) 47.5 kV/mm
Surface Resistance 5.0 x1011 Ohm
Coefficient of friction dry against steel 0,21
Coefficient of friction depending on lubricant ~0,1