Abstract: An adaptive hydraulic engine mount for mounting an engine to a frame of a motor vehicle includes a pumping chamber and reservoir filled with damping fluid and an orifice track or damping channel communicating the pumping chamber with the reservoir. A decoupling diaphragm responds to pressure level in a control cavity to control pumping of damping fluid through the damping channel, thereby controlling the dynamic stiffness of the mount. Upon actuation of a control valve, the pressure level in the control cavity is changed to achieve a level of damping greater than the low damping level. According to another embodiment of the invention, the control cavity can be communicated with engine vacuum to achieve maximum damping, or air may be trapped in the control cavity to achieve an intermediate level of damping, or the control cavity may be communicated to atmosphere to provide low levels of damping.

Abstract: A hydraulic mount includes a mounting plate and a wall, with a working chamber defined between the mounting plate and the wall. The mounting plate and the wall are separated by a relatively thick elastomeric element so that the size of the working chamber varies as the elastomeric element is compressed and expanded by operation of the mounting plate and the wall moving closer together and farther apart. A reservoir is defined substantially by the elastomeric element in combination with a relatively flexible diaphragm that extends between the mounting plate and the wall so that the reservoir is generally annular in shape and is positioned around the working chamber. The elastomeric element serves as a separation wall between the working chamber and the reservoir.

Abstract: In a duo-pumping hydraulic mount, two acting pistons are employed, one associated with each working chamber. The pistons are rigidly connected. During operation, internal pressures generated in each chamber are opposite in sign with one being negative and the other being positive. Therefore, to achieve a given pressure differential across the fluid track, the magnitude of the pressure in each working chamber is half what would be experienced in a conventional single pumping mount. Durability is improved by reducing internal pressures and by distributing kinetic loads to two rubber elements so that individual stresses are minimized. An individual load bearing element supports static loads on the mount.

Abstract: A hydraulic mount is operable in soft and firm modes and includes a valve positioned at the partition between the working chamber and the reservoir. A normally open fluid path extends through the partition and opens between the working chamber and the reservoir for soft operational characteristics useful in attenuating low amplitude vibrations. The valve body and the partition together define a control chamber in the fluid path. The control chamber is open to the reservoir through lateral openings in the valve body so that fluid pressure in the control chamber is approximately at atmospheric pressure so that a small actuator can move the valve. When the valve is closed the fluid path is closed for firm operational characteristics in controlling large amplitude inputs such as those from torque transients.