Hybrid elastomer-and-metal spring isolator
AssigneeLord Corporation
InventorJames T. Gwinn
Life of this patent
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Abstract
A hybrid elastomer-and-metal spring isolator with a low natural frequency. A fully bonded sandwich mount has cored pockets that receive metal coil springs. Extruded cavities on the lower and upper plates of the sandwich mount extend into the pockets within the interior of the coiled springs and receive a tension bolt and double lock-nut assembly to secure the separate lower cavities to the isolator. A preload retention nut engages a protruding portion of the tension bolt and preloads the coil springs to an amount equal to their static load. This hybrid isolator has particular application in mounting large (30 ton) diesel engines; the isolator assembly provides a natural frequency that is between 3 and 5 Hz, outside the normal idling frequencies of the engine so as to avoid resonance.
Claims24
A hybrid elastomer-and-metal spring vibration isolator of general utility and with specific utility for supporting a large internal combustion engine and isolating its low frequency vibrations, said isolator comprising:
- a) an elastomeric sandwich mount including a large elastomer section positioned between a first lower metal plate and a second upper metal plate, said section having a first plurality of cored out metal-spring receiving pockets;
- b) a second plurality of metal helical coil springs received in said cored out regions, said second plurality being equal to said first plurality;
- c) means to preload said elastomer-and-metal spring isolator by an mount between 50% and 100% of a static load said isolator will experience when supporting said large internal combustion engine.
A hybrid elastomer-and-metal spring isolator for supporting a large internal combustion engine and isolating its low frequency vibrations, said isolator comprising:
- a) an elastomeric sandwich mount including a large elastomer section positioned between a first lower metal plate and a second upper metal plate, said section having a first plurality of cored out metal-spring receiving regions;
- b) a second plurality of metal helical coil springs received in said cored out regions, said second plurality being equal to said first plurality;
- c) means to provide cushioned snubbing of movement between said first and second plates after a limited amount of movement in each of an axial expansion and an axial compression direction.
A hybrid elastomer-and-metal spring mounting system for supporting a large internal combustion engine and isolating its low frequency vibrations, said mounting system comprising:
- a plurality of pairs of hybrid mounts, each mount including
- i) an elastomeric sandwich mount including a large section of elastomer positioned between a first lower metal plate and a second upper metal plate, said section having a first plurality of cored out metal-spring receiving regions;
- ii) a second plurality of metal helical coil springs received in said cored out regions, said second plurality being equal to said first plurality;
- whereby each pair of hybrid mounts is oriented to semi-focalize said mounting system thereby decoupling a lateral-vibratory mode of response from a rolling mode of response associated therewith.
A method of mounting a diesel engine comprising the steps of
- i) providing a support platform which does not require complicated mounting pad machining to allow for structural camber;
- ii) providing a plurality of hybrid elastomer-and-metal spring vibration isolators;
- iii) preloading each of said vibration isolators to a first level of preload equal to its share of static load when supporting said diesel engine using a securement means which has a first attachment for producing said first level of preload and a second attachment which produces a second lower level of preload;
- iv) securing each of said plurality of isolators to said skid;
- iv) removing said first attachment of each of said isolators allowing said isolator to expand to said second level of preload;
- v) positioning said diesel engine on said plurality of isolators recompressing said isolator an amount equal to said first level of preload;
- vi) securing said diesel engine to said skid in fixed position on said plurality of isolators.
Dependencies are inferred from the claim text.