Servofloat®
Sealing System Cover
The Servofloat® sealing system in the cover, featuring the floating gap seal, is ideal for particularly low-friction and highly sensitive movements. The use of the patented floating gap seal enables extremely stick-slip-free movements to be achieved. Servofloat® is also suitable for highly dynamic movements and oscillations, as well as for cylinder loads with high side loads.
Function
The cylinder pressure is reduced to the outside in a non-contacting manner by a narrow throttle gap. The design-related self-centering of the floating gap seal causes a low functional oil flow. The functional oil is discharged into the tank at the functional oil port L.
The contacting (functional oil) seal and the wiper ring are not under pressure, resulting in very low residual friction that remains constant over the entire pressure range.
Seal combination
- Floating gap seal
- Functional oil seal
- Wiper ring
Depending on the series, the sealing materials and the guiding system, this system is suitable for:
| Piston speeds | up to 4 m/s |
| Temperature range | from -30 °C to +100 °C |
The Servofloat® sealing system requires a minimum pressure in the chamber of pmin = 50 bar to guarantee centering.
The functional oil flow is discharged into the tank without pressure at the functional oil port. It must not be extracted with vacuum. A preload of the functional oil line up to 5 bar is permissible.
Series 320:
The functional oil ports are internally connected for optional connection.
All other series:
The functional oil ports must be connected externally.
The amount of functional oil produced is highly dependent on the viscosity of the fluid used, the temperature and, in particular, the pressure conditions prevailing in the cylinder. In addition, other factors must be taken into account when determining the functional oil flow.
The functional oil quantities shown here were determined for a fluid ISO VG 46 at 55°C. However, they should only be used as guide values for the hydraulic design; an exact determination of the functional oil flow can only be carried out on the device itself by means of measurements.
|
Functional Oil Flow Servofloat® |
||
| Rod diameter [mm] |
Functional oil min.* [l/min] |
Functional oil max.* [l/min] |
| 25 | 0,25 | 0,5 |
| 30 | 0,4 | 0,8 |
| 40 | 0,4 | 0,8 |
| 50 | 0,8 | 1,2 |
| 63 | 0,8 | 1,2 |
| 80 | 1,7 | 3,0 |
| 100 | 2,0 | 3,5 |
| 125 | 7,0 | 9,0 |
| 160 | 7,0 | 9,0 |
* The functional oil data for Servofloat® applies to one chamber at 210 bar chamber pressure (working pressure).