Patent Application
20060043654
The present invention relates generally to mounts and in particular the present invention relates to “energy-managing” mounts for connecting a vibration source to a support structure.
A vibration source, such as an engine, is typically mounted on a support structure, such as a vehicle that is powered by the engine, using mounts. Mounts are typically used to reduce the transmission of vibration energy from the vibration source to the support structure. Another application involves using mounts to mount an engine for generating power for shelters, such as used by the military, to its support structure to reduce the transmission of vibration energy from the engine to the shelter. Examples of common mounts include, but are not limited to, metal and air springs, elastic mounts, and viscoelastic mounts. However, these mounts are often only effective for limited range of operating frequencies. Moreover these mounts are not very effective for applications involving shocks due to vehicle operation or when a vehicle is deployed by parachute for some military applications.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for alternative mounts for mounting vibration sources to support structures.
The above-mentioned problems with mounts and other problems are addressed by the present invention and will be understood by reading and studying the following specification.
The various embodiments relate to mounts (e.g., “energy-managing” mounts) that are self-reconfigurable in that they can reconfigure their phase from soft to hard due to the loading thereon, e.g., using a nonlinear stiffness characteristic, with relatively consistent vibration damping over a broadband of vibration frequencies.
One embodiment of the invention provides a mount adapted to connect a vibration source to a support structure. The mount includes a first elastomeric layer having a first stiffness, and a second elastomeric layer connected to the first elastomeric layer and having a second stiffness that is different than the first stiffness.
Another embodiment of the invention provides a mount adapted to connect a vibration source to a support structure. The mount includes a bracket, a first elastomeric layer having a first stiffness overlying a portion of the bracket, a second elastomeric layer overlying the first elastomeric layer and having a second stiffness that is different than the first stiffness, a third elastomeric layer having the first stiffness and underlying the portion of the bracket so that the portion of the bracket is sandwiched between the first and third layers.
Another embodiment of the invention provides a method of operation of a mount adapted to connect a vibration source to a support structure. The method includes dissipating vibration energy from the vibration source using a first layer of the mount, and absorbing shock load energy using a second layer of the mount that is connected in series with the first layer.
Another embodiment of the invention provides a method of connecting a vibration source to a support structure. The method includes disposing first and second elastomeric layers between the vibration source and support structure so that the second layer is located between the first layer and the vibration source, wherein the first and second layers have different stiffnesses.
Further embodiments of the invention include methods and apparatus of varying scope.
In the following detailed description of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. In the drawings, like numerals describe substantially similar components throughout the several views. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and equivalents thereof.
For one embodiment, a third layer 140 of elastomeric material, e.g., neoprene, having the first stiffness underlies bracket 110 so that a portion of bracket 110 is sandwiched between the third layer 140 and the first layer 120, as shown in
For one embodiment, the second stiffness of the elastomeric material of the second layer 130 is nominally greater that the first stiffness of the elastomeric material of the first layer 120 or the first layer 120 and the third layer 140. For another embodiment, the second stiffness of the elastomeric material of the second layer 130 increases with increasing load on the second layer 130, e.g., in a nonlinear fashion.
For one embodiment, bracket 110 has a U-shaped portion 170 that contains the third layer 140 and plate 150, as shown in
During operation, the sandwiching of cross member 172 of bracket 110 between the first layer 120 and the third layer 140 acts to reduce vibration that is transmitted to structure 250 from vibration source 200. This acts to reduce the structural borne sound (noise) inside a vehicle that includes structure 250 or an adjacent shelter or structure connected to structure 250. Note that third layer 140 may be eliminated for some embodiments. For these embodiments, the first layer 120 acts to reduce vibration that is transmitted to structure 250 from vibration source 200. The second layer 130 acts absorb energy flow associated with shock (or impact) loading generated, e.g., during the vehicle operation or when the vehicle is deployed, e.g., by parachute for military applications.
Therefore, mount 100 acts to dissipate lower load vibratory energy, and thus noise, and to absorb the higher shock-load energy flow between vibration source 200 and support structure 250 substantially simultaneously. This means that mount 100 is self-reconfigurable in that it can reconfigure its phase from soft to hard due to the loading thereon, e.g., using the nonlinear stiffness characteristic of the second layer 130, with relatively consistent vibration damping over a broadband of vibration frequencies. That is, the first layer 120 or the first layer 120 and the third layer 140 act as vibration and noise reducing layers and the second layer 130 acts as a shock load absorbing layer. For other embodiments, the second layer 130 also acts to support the weight of vibration source 200.
It will be appreciated that for some embodiments, the first layer 120 and the second layer 130 may be interchanged, with the second layer 130 overlying cross member 174 of bracket 110 and the first layer 120 overlying the second layer 130 and that further vibration damping and/or shock absorbing layers could be added.
The various embodiments relate to mounts, e.g. (“energy-managing” mounts) that are self-reconfigurable in that they can reconfigure their phase from soft to hard due to the loading thereon, e.g., using a nonlinear stiffness characteristic, with relatively consistent vibration damping over broadband of vibration frequencies. For one embodiment, a mount that is adapted to connect a vibration source to a support structure has a first elastomeric layer having a first stiffness, and a second elastomeric layer connected to the first elastomeric layer and having a second stiffness that is greater than the first stiffness.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. Many adaptations of the invention will be apparent to those of ordinary skill in the art. Accordingly, this application is intended to cover any adaptations or variations of the invention. It is manifestly intended that this invention be limited only by the following claims and equivalents thereof.
