Sleeveutvidelsesklaff

Sleeveutvidelsesklaff, often translated as sleeve expansion flap, is a mechanical component used to create a sealing interface and accommodate relative motion between a rotating shaft and its housing. The device consists of a flexible flap or skirt that is hinged or slotted to a sleeve. When the shaft rotates, centrifugal forces or pressure differences cause the flap to flex outward, thus expanding the sleeve and closing gaps that would otherwise allow leakage.

The main purposes of a sleeveutvidelsesklaff are to reduce fluid escape, damp vibration, and compensate for wear or mis‑alignment in the rotational assembly. It is typically constructed from elastomeric materials reinforced with metal, or from spring‑loaded metal plates, depending on the operating temperature, pressure, and lubricants involved.

This component is common in hydraulic cylinders, automotive transaxles, and various industrial drives. In hydraulic applications the flap provides a dynamic seal that remains effective over a wide range of pressures, eliminating the need for separate packing. In transmissions it helps reduce noise and improve torque transmission by keeping the gear train free of contaminants.

The concept was introduced in the 1950s within Scandinavian mechanical engineering circles, where many automotive and industrial patents describe versions of the sleeveutvidelsesklaff. Modern designs have evolved to include multi‑flap arrays for higher load capacity and improved sealing. Despite its relative obscurity, the sleeve expansion flap remains an important part of many precision mechanical systems.