Abstract: A hydraulically damped mounting device has two anchor parts connected by a resilient wall which applies a spring force to relative vibrations of the anchor parts. Also connected to the anchor parts are two bellows walls each defining a corresponding chamber for hydraulic fluid, which chambers are interconnected by a passageway. The bellows walls deform substantially freely of spring resistance and so the volume of the corresponding chamber can change without spring resistance. Thus there is a pumping action of fluid between the chambers, giving a damping action due to the passageway, and hence the spring and damping characteristics of the mount are independently selectable.

Abstract: A hydraulically damped mounting device has two bushes connected together by an elongate bar. Each bush has a housing containing an anchor point connected to the housing by a resilient spring. Each spring, and part of the corresponding housing defines a working chamber for hydraulic fluid, the working chambers being interconnected by a passageway in the bar. The working chambers are positioned in the housing so that movement of the anchor points in opposing directions causes a decrease in size of one working chamber and an increase in size in the other. This change in size causes fluid movement through the passageway, and this exerts damping on the movement of the anchor points. Thus, when the device is connected between two objects with each anchor point connected to a corresponding one of the objects, relative vibration of the objects, and in particular torsional vibration may be damped.

Abstract: A hydraulically damped mounting device has two anchor parts, in the form of a sleeve and a tube, connected together by a resilient wall. The resilient wall and the sleeve define a working chamber for hydraulic liquid which is connected to a compensation chamber by a passageway. The passageway may extend directly through the tube or peripherally of the sleeve. The compensation chamber is bounded by a bellows wall, permitting the volume of the compensation chamber to change freely as vibrations of the tube relative to the sleeve change the volume of the working chamber, without the bellows wall being subject to tensile stresses. The sleeve may be formed in two parts which are forced together during manurfacture, enabling a compact construction to be achieved.

Abstract: A hydraulically damped mounting device has two anchor points joined by a resilient spring. The resilient spring and a partition define a working chamber for liquid, the working chamber being in communication with a compensation chamber via a passage. The compensation chamber is bounded by flexible bellows. A flexible diaphragm defines, together with the partition a gas pocket. Relative movement of the anchor points causes a change in pressure in the working chamber. High frequency vibrations are absorbed by movement of the diaphragm with little resistance to movement. Low frequency vibration cause liquid movement through the passage with a strong damping effect. This affect may be controlled by suitable selection of the length and diameter of the passage. Preferably, a bleed orifice extends from the gas pocket to compensate for thermal changes in the volume of the pocket.