Pneumatically-controlled hydraulic antivibration support, and a motor vehicle including such a support

A hydraulic antivibration support for interposing between two rigid elements and comprising:

• first and second rigid strength members for fixing to the two rigid elements that are to be united;
• an elastomer body interconnecting the two strength members and defining part of a liquid-filled working chamber, said elastomer body being adapted to support a static load directed along a central axis;
• a flexible elastomer wall forming two adjacent bags which define respectively a compensation chamber and an additional hydraulic chamber, both filled with liquid and connected to the working chamber respectively via a constricted first passage and via a second passage;
• a rigid partition extending perpendicularly to the central axis and secured to the second strength member, said rigid partition separating the working chamber from the compensation chamber and from the additional hydraulic chamber;
• a rigid protective cup covering the flexible wall and encompassing both the compensation chamber and the additional hydraulic chamber, said protective cup having an end wall and a peripheral side wall fixed to the second strength member;
• and
• a rigid thimble which has an annular side wall extending in the direction of the central axis between a closed end wall and an open end, said thimble being pressed against the flexible wall and clamping said flexible wall in leakproof manner against the rigid partition around the second bag formed in said flexible wall so as to separate the compensation chamber from the additional hydraulic chamber, and said thimble presenting an inside surface which co-operates with said second bag to define a pneumatic chamber communicating with a pneumatic duct;
• wherein the additional hydraulic chamber is adjacent to the side wall of the protective cup;
• wherein the compensation chamber is juxtaposed to said additional hydraulic chamber without surrounding said additional hydraulic chamber, said compensation chamber being in contact with the rigid partition via a first surface area that is more than four times greater than a second surface area of said rigid partition which is in contact with the additional hydraulic chamber;
• and
• wherein the thimble extends parallel to the central axis to the end wall of the protective cup, the second bag of the flexible wall extending at rest to the vicinity of the end wall of said thimble.