Vibration damper VD11 black

Vibration dampers in the VD11 series are cylindrical rubber dampers with a threaded stud at both ends. The damper is screwed in between two components and breaks the rigid connection; vibrations and structure borne noise that would otherwise travel straight through the structure get caught in the rubber on the way. The type is often called male to male after the studs and is the standard choice when both sides have threaded holes.

The principle is as simple as it is old. A cylinder of rubber sits between two threaded studs in zinc plated steel, and when one side vibrates the rubber takes up the movement before it reaches the other side. Without dampers the whole frame works as a sounding box; with dampers the noise stops at the source. The same technique sits in everything from washing machines to ship engines, and what differs is the size and the rubber compound.

The hardness is 55 Shore A with a tolerance of plus minus 5, a middle value that makes the series useful in most lighter applications. The rubber is soft enough to work even at small amplitudes and at the same time firm enough to carry the equipment without it standing there swaying. Shore A is incidentally the same scale used for wheel treads and seals; 55 corresponds roughly to an ordinary eraser.

The temperature range runs from minus 40 to plus 80 °C, which covers cold rooms, outdoor installation and normal machine heat. Just remember that the properties of the rubber change toward the outer edges of the range; cold rubber becomes stiffer and damps less, warm rubber becomes softer. For outdoor installation it is incidentally the UV light of the sun rather than the cold that ages the rubber in the long run.

The dimensions span very widely. The series covers 67 versions, from 6 mm diameter with M3 studs up to 200 mm diameter with M20; in between the rubber body and the thread grow step by step. At the lower end these are dampers for small things, fans, small pumps, electronics chassis, sensors and displays; at the upper end the dampers carry compressors, units and other machine equipment. Electronics is a rewarding example; a small fan screwed straight into a sheet metal box turns the box into a loudspeaker, but four small dampers in between quiet the structure almost completely.

The chemical environment sets the limit. The rubber should not be used in contact with oil, alkaline agents or acids; in such environments the material breaks down and the damper loses both shape and function. Water and normal humidity are no problem. If the damper sits in oil mist from a machine it is the wrong product, however well it works mechanically.

Fitting is done between two threaded holes or with nuts. Tighten moderately; the slimmest threads in particular do not take much torque, and the rubber should not be preloaded harder than necessary, since a hard compressed damper damps worse. If the joint wants to come loose from the vibrations, a drop of thread locking compound is better than higher torque. Check after a period of operation that nothing has worked loose.

The choice between versions is governed by space and load. A taller damper gives more rubber to work with and therefore softer isolation, while a lower one builds less and stands more stable sideways. The basic rule is to spread the weight over several dampers so each one works in its soft range; for exact load values per version we refer to the data sheet.

The pack quantity varies with the size; the smallest dampers are supplied in 200 pieces.

Do you want help calculating the damping in your design? Contact us with your operating data.