International

High Performance Cylinderfor Testing Technology

In component and material testing facilities of research and development departments as well as in structural testing facilities of numerous industrial sectors, the materials, components and structural elements to be tested are exposed to mechanical loads to test their function, suitability for specific applications, degree of wear and life cycle.

Apart from electro-mechanical drives, hydraulic drives in the form of linear actuators are used to provide the required mechanical loads in particular with highly dynamic load profiles.

To ensure an excellent control quality of the drive even if highly dynamic motion is required, primarily double-acting cylinders in servo quality with low friction resistances are employed.

The High Performance series with plain bearings is an inexpensive alternative to the conventional and widely used servo cylinders with hydrostatic pocket bearings.

With constant, pressure independent frictional values, which are definitely comparable to classic servo cylinders, the modular kit with a forces of 16, 40, 63, 100 and 250 kN covers a wide range of applications in testing technology.

The price advantage gained due to a more cost-effective sealing and bearing concept when compared to series with pocket bearings, limits the technical usability only marginally. Primarily, the limited capacity of bearing lateral forces transverse to the movement axis, which may be caused e. g. by masses to be moved, own weight (depending on the installation position) and transverse acceleration occurring by interaction with other actuators, has to be taken into account.

System Set-up / Mode of Operation

The High Performance series of cylinders has a modular design. The modular kit providing five force levels and two pre-defined mounting styles, “base side self-aligning clevis” or “head flange”, in combination with a standardized external or internal thread for connection to the piston rod, allows for a variable configuration of the cylinder, tailored to the mechanical interfaces of the specific application.

For both mounting styles, the cylinder can be equipped with an integrated magnetostrictive displacement transducer for position sensing.

In its basic design, the High Performance Cylinder is generally equipped with a connection block forming the connection from the directional valve to the two cylinder chambers on the one hand, providing the SAE flange connections for the connection to the pressure oil supply on the other hand and enabling the return flow to the tank.

Furthermore, the pressure accumulator in the pump port and the damping accumulator in the tank port as well as measuring points equipped with connection couplings for the two cylinder chambers and the pump and tank port are integrated in the connection block.

The mounting pattern of the control valve is standardized according to ISO 4401. This means that sandwich plates can be used to add additional functions commonly required in testing technology.

The coextensive effective areas of the piston in both cylinder chambers ensure good controllability even with highly dynamic motion of the cylinder, which can be used up to a frequency of 50 Hz. The favorable controllability is supported by the extremely low constant and pressure independent friction, amounting to a maximum of 1% of the nominal force of the cylinder. The pipe connections as well as the connections from the connection block to the cylinder chambers are designed for flows enabling a cylinder velocity of up to 2 m/s.

Custom variations of the configurations and limitations predefined by the preference series are generally feasible. Prior consultation with the specialist department is, however, required and a deviation from the indicated delivery times may be involved.

Technical Parameters

  • Nominal force levels: 16, 40, 63, 100 and 250 kN
  • Mounting style: MF3 and MP5
  • Nominal pressure: 280 bar
  • Working stroke: 50 up to 500 mm
  • Typical frequency: up to 50 Hz
  • Velocity: 0,01 up to 2 m/s
  • Acceleration: up to max. 50 g
  • Pressure independent friction
  • Applications without lateral force

Features

  • Cost-effective amendment to the control cylinder range for highly dynamic test equipment
  • Short delivery times due to a predefined modular concept
  • Favorable controllability due to pressure independent constant friction
  • Connection plate with integrated flange connections for P and T
  • Additional functions can be optionally integrated using sandwich plate design