berg-ovrk

Hydraulic Cylinder - OVRK

Hydraulic cylinder with closed center

The rotating hydraulic cylinders type OVR and OVRK are designed for actuating power operated chucks.

With the maximum permissible pressure of 80 bar, large operating forces can be produced at considerably lower mass and inertia forces than in the past. At the same time, due to a wide pressure setting range, it is possible to actuate several chuck sizes using one cylinder size without any limitations.

OVRK hydraulic cylinders are equipped with a rotating coolant union KDE8-1 for fluid supply into the chip removal area. The maximum permissible coolant lubricant pressure pK is 70 bar. No additional control system is required for a dry run.

Design features
The rotating hydraulic cylinders type OVR(K) are designed for actuating power operated chucks. With the maximum permissible pressure of 80 bar, large operating forces can be produced at considerably lower mass and inertia forces than in the past. At the same
time, due to a wide pressure setting range, it is possible to actuate several chuck sizes using one cylinder size without any limitations.

Hydraulic cylinders type OVR(K) comprise a rotating cylinder equipped with unlockable non-return valves, a hydraulic rotary transmission leadthrough moving axially with the piston stroke and a connected stroke control device. This construction permits a compact design.
OVRK hydraulic cylinders are equipped with a rotating coolant union KDE8-1 for fluid supply into the chip removal area. The maximum permissible coolant lubricant pressure is 70 bar. No additional control system is required for a dry run.

The patented BERG valve system maintains the clamping pressure in the cylinder in the event of a sudden decrease in pressure. In clamping position it allows the infinitely variable reduction of the clamping pressure. Pressure peaks from the hydraulics or as a result
of clamping pressure increases due to heating which can lead to constant overloading of the clamping means, are rendered ineffective.

OVR(K) hydraulic cylinders are equipped in the represented standard design with a stroke control device which is prepared with an analogue output for fitting an inductive proximity switch. Detection of the entire stroke throughout the conically shaped cylinder body is
possible. Hydraulic cylinders with a raised edge energizing inductive proximity switches in the final position are available as an option.

The fastening flanges are custom made to fit the respective machine and to ensure optimum cylinder adaption to the spindle diameters. To this effect please specify the dimensions marked with including tolerances.

BERG valve system
The valve system is effective in both directions of actuation (push and pull). The opening pressure is 4 bar. Before using self-regulating positive displacement pumps, check whether the delivered flow is sufficient to ensure an adequate piston speed at minimum pressure.
To guarantee the function do not install any non-return valves downstream of the pump.

Filter regulations
Ensure that a pressure filter is fitted between the pump and the solenoid valve (filter fineness 0.010 mm absolute, filtering coefficient 75). The minimum filter fineness for the coolant lubricant is 0.060 mm.

BERG valve system
The valve system is effective in both directions of actuation (push and pull). The opening pressure is 4 bar. Before using self-regulating positive displacement pumps, check whether the delivered flow is sufficient to ensure an adequate piston speed at minimum pressure.
To guarantee the function do not install any non-return valves downstream of the pump.

Filter regulations
Ensure that a pressure filter is fitted between the pump and the solenoid valve (filter fineness 0.010 mm absolute, filtering coefficient 75). The minimum filter fineness for the coolant lubricant is 0.060 mm.