Kaco CYBU cushion seals have been developed especially for cushioning in pneumatic cylinders. They carry out the function of sealing the cushioning piston together with the desired check valve effect.

The cushioning process begins when the cushioning piston moves into the CYBU sealing ring. In this case, the cylinder chamber is sealed off from the cushion cylinder. This takes place in that the dynamic sealing lip comes into contact with the cushioning piston and that the crowned floor side of the sealing ring is pressed onto the front surface of the groove (figure 24). The increased pressure in the cylinder chamber can now only be diminished via the throttle.

In the case of pressure from the cushion cylinder, the CYBU sealing ring is raised from the static seal fit and the crowned-shaped lug cams come into contact on the opposite groove end. In this case, the pressure medium flows without pressure loss into the cylinder chamber through the radially and axially located recesses and causes immediate movement of the piston rod (figure 25). The pressure necessary for raising the axial sealing fit of the CYBU rings lies below 0.1 bar.

The radial clearance of the CYBU cushion seal in its location hole guarantees full operability and high cushioning, even if the cushioning piston is centrally displaced with respect to the cushion cylinder. This radial clearance is taken into consideration in the table of dimensions.

This is installed in the groove by snapping on by hand or, in the case of an opened hole, by manual insertion and subsequent insertion of a retaining ring.

If, for certain special cases, you intend to use special CYBU designs — for example, with a dynamic sealing lip on the external diameter for installation in cushion pistons — please get into contact with us. We will be pleased to advise you.

Technical data:

Pressure range     ≤ 16 bar

Permissible sliding speed    ≤ 1 m/s
Tolerances

dynamic (cushion piston)   H10

static (housing)     H11