Spring devices – Resilient shock or vibration absorber – Including energy absorbing means or feature
Reexamination Certificate
1999-03-24
2001-04-24
Oberleitner, Robert J (Department: 3613)
Spring devices
Resilient shock or vibration absorber
Including energy absorbing means or feature
Reexamination Certificate
active
06220584
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an engine bearing, and in particular to a hydraulically damping engine bearing including fluid-filled chambers bordered at least partially by elastic walls, a limitedly deflectable diaphragm separating the chambers and at least one channel connecting the chambers.
2. Description of the Related Art
Engine bearings are known (e.g., German reference DE 34 46 725 C2) in which a separating wall is arranged between two chambers, where one chamber has an elastic diaphragm running in annular fashion on a rigid outer wall. An intermediate space formed by the elastic diaphragm and the rigid outer wall can be pressurized with an underpressure or vacuum to attain high rigidity of the engine bearing. If, during driving operation, the engine bearing is to be placed in the high rigidity state, it is necessary to apply the underpressure in the intermediate space so that the elastic wall thereby lies directly on the rigid outer wall of the bearing.
Further, engine bearings are known (e.g., German reference DE 42 38 752 C1) in which the chambers separated by a diaphragm are equipped with a flexible wall arranged in one of the chambers, for the purpose of changing the bearing characteristic. The bearing characteristic is changed by virtue of the fact that at low rigidity of the bearing, at least one of the hydraulic chambers works against a gas volume enclosed in the intermediate space, whereas at high rigidity, the flexible wall comes at least partially to rest on a stop. To aerate the intermediate space, a switch opens a flow connection to atmosphere or a pressure storage device, while to de-aerate, a valve is arranged in the flow connection. In a configuration of this type, the flexible wall is an integral part of a complete rubber bearing.
In addition, rubber bearings are known (e.g., German references DE 41 14 879 A1, DE 41 20 841 C1, DE 41 30 362 C2 and DE 41 03 028 C2) that are configured so that their rigidity is controllable. These rubber bearings are similar to conventional bearings, however, auxiliary energy in the form of pneumatic pressure or hydraulic pressure is required. FIG. 4 in German reference DE 41 30 362 C2 shows a bearing equipped with a mechanical adjustment device.
Also known (e.g., PCT reference WO 96/17184), is a hydraulically damping engine bearing with a conventional suspension spring connected in series. However, the conventional suspension spring is taken out of operation in the high rigidity position. Disadvantageously, an expensive switching module is required. Moreover, auxiliary energy in the form of pressure is also required.
SUMMARY OF THE INVENTION
Accordingly, it is an object therefore of the present invention to provide a hydraulically damping engine bearing that is controllable and that isolates engine vibrations, especially in idle operation, and whereby an additional switchable reduction in static and dynamic rigidity levels is ensured.
To attain this object, the present invention provides a hydraulically damping engine bearing, including; fluid-filled chambers; elastic walls at least partially bordering the chambers, a limitedly deflectable diaphragm separating the chambers, and a channel in communication with the chambers. An additional suspension spring arranged outside of one of the chambers. An intermediate space, defined by the additional suspension spring and an outer wall of the chamber, is aerated and de-aerated by use of a valve.
In an advantageous embodiment of the present invention, the additional suspension spring is relatively soft and is connected in series to a modern conventional hydraulically damping engine bearing. Series-produced engine bearings are used as the engine bearing. The additional suspension spring is associated with a bearing cover, so that an intermediate space is formed between an outer surface of the bearing cover and an inner surface of the additional suspension spring. The additional suspension spring is equipped with an attachment part for attachment in a vehicle. This embodiment allows production of switchable or adaptive engine bearings that have a comparatively simple structure.
According to another embodiment of the present invention, the additional suspension spring has a different Shore hardness than a Shore hardness of the elastic wall of the chambers.
It is advantageous that, in a further embodiment of the present invention, a serial connection is used to connect the engine bearing to the additional suspension spring. This effectively produces a soft total spring rate in the axial and radial directions. Furthermore, the serial connection achieves a frequency-independent reduction of the spring rates of the total system.
In yet another embodiment of the present invention, the additional suspension spring is prestressed. A stop is provided to limit the spring path of the additional suspension spring. The axial deflection of the additional suspension spring is limited in one direction by the rigid bordering wall of a chamber and in the other direction by the stop.
In still another embodiment of the present invention, the additional suspension spring, in an unloaded state of the total system, is prestressed by the stop so that under the influence of a static load, the suspension spring assumes a position inside the stop and the rigid bordering wall. Advantageously, the suspension spring assumes a central position between the stop and the rigid bordering wall.
In still another embodiment of the present invention, the stop is configured as a cup-shaped element which is securely connected to the engine bearing.
According to a further embodiment of the present invention, the valve is configured as a non-return valve. In this embodiment the additional suspension spring is also deflected by tensile and pressure movements of the engine bearings. Therefore, the intermediate space is pumped empty via the non-return valve and by the pumping work of the additional spring. Such an engine bearing advantageously requires no additional energy, e.g., pressurized air or hydraulic fluid.
In yet a further embodiment of the present invention, the valve is externally controllable, preferably being configured as a magnetic valve.
In an additional embodiment of the present invention, a flow connection is provided between the valve and the intermediate space. Preferably, the flow connection is arranged so as to run through the additional suspension spring.
And in still another embodiment of the present invention, when the additional suspension spring rests on the rigid bordering wall, the spring rate of the total system corresponds approximately to the spring rate characteristic of the engine bearing.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
REFERENCES:
patent: 4765601 (1988-08-01), Miller et al.
patent: 4828234 (1989-05-01), Hoyer et al.
patent: 5205546 (1993-04-01), Schisler
patent: 5228663 (1993-07-01), Adler et al.
patent: 5280886 (1994-01-01), Gartner et al.
patent: 5386977 (1995-02-01), Quast
patent: 5401008 (1995-03-01), Winkler et al.
patent: 6082718 (2000-07-01), Yamada et al.
patent: WO96/17184 (1996-06-01), None
Cohen & Pontani, Lieberman & Pavane
King Bradley
Mannesmann Boge GmbH
Oberleitner Robert J
LandOfFree
Hydraulically damping engine bearing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydraulically damping engine bearing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydraulically damping engine bearing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2480109