Damped vibration isolation system
AssigneeMinus K. Technology, Inc.
InventorDavid L. Platus
Life of this patent
Estimating the term…
Abstract
An improved vibration isolation system utilizes a damped elastic structure loaded to approach a point of elastic instability to reduce the stiffness of the structure and to increase the damping. The system provides very low amplification at system resonant frequencies and effectively isolates at higher frequencies.
Claims26
A vibration isolation suspension system for supporting an object having mass in an acceleration field and maintaining the object in an equilibrium position relative to a base while suppressing transmission of vibratory motion between the object and base comprising:
- a plurality of elastic structures, each having a first end connected to the object and a second end connected to the base, said first and second ends defining an axial direction, and
- damping means operative with said elastic structures for providing damping to the system, wherein each of said elastic structures have transverse stiffness in response to displacement of said first end relative to said second end in any direction substantially transverse to the axial direction and stiffness in the axial direction to support the object, each of said elastic structures having a point of elastic instability in response to loading in the axial direction where at the point of elastic instability said elastic structure has zero or near zero transverse stiffness, each of said structures being loaded in the axial direction to approach its point of elastic instability to cause a substantial reduction of its transverse stiffness while maintaining sufficient axial stiffness to support the object.
A method for reducing transmission of vibration between an object and a base comprising the steps of:
- connecting the object to the base on suspension means which exhibits positive stiffness and damping;
- and
- applying negative stiffness between the object and the base for counteracting the positive stiffness and increasing the damping of the suspension means.
A method for reducing transmission of vibration between an object and a base comprising the steps of:
- connecting the object to the base with an elastic structure and a damping element which are operatively connected;
- and
- applying load to the elastic structure to cause at least a portion of the structure to approach a point of elastic instability.
A method for reducing transmission of vibrations between an object and a base comprising the steps of:
- connecting the object to the base with an elastic structure and a damper which are operatively connected;
- and
- applying load to the elastic structure to cause at least a portion of the structure to be loaded beyond a point of elastic instability.
A method for reducing the net stiffness of a vibration isolation system connected between an object and a base in which the object includes a member connected between the object and base which imparts positive stiffness between the object and the base, comprising the steps of:
- connecting the object to the base with an elastic structure;
- and
- applying load to the elastic structure to cause at least a portion of the structure to approach a point of elastic instability.
A method for adding damping to a vibration isolation system connected between an object and a base in which the object includes a member connected between the object and the base which imparts positive stiffness between the object and the base, comprising the steps of:
- connecting the object to the base with an elastic structure;
- and
- applying load to the elastic structure to cause at least a portion of the structure to approach a point of elastic instability.
A vibration isolation suspension system for supporting an object having mass in an acceleration field which defines an axial direction while maintaining the object in an equilibrium position relative to a base and suppressing transmission of vibratory motion between the object and base, comprising:
- an elastic structure having axial stiffness and adapted to receive a compressive loading force, said elastic structure having an end for supporting the object and comprising a multiple-layered flexure having an inner layer made from a structural material surrounded by two outer layers made from structural materials, said inner and outer layers being operatively connected to the object, said elastic structure having a point of elastic instability in response to application of a compressive loading force where at the point of elastic instability said elastic structure has substantially zero axial stiffness, said elastic structure being loaded to approach a point of elastic instability to cause a substantial reduction of its axial stiffness;
- and
- means for applying a compressive loading force to said elastic structure.
A vibration isolation suspension system for supporting an object having mass in an acceleration field which defines an axial direction while maintaining the object in an equilibrium position relative to a base and suppressing transmission of vibratory motion between the object and base, comprising:
- an elastic structure having axial stiffness and adapted to receive a compressive loading force, said elastic structure having an end for supporting the object and a point of elastic instability in response to application of a compressive loading force where at the point of elastic instability said elastic structure has substantially zero axial stiffness, said elastic structure being loaded to approach a point of elastic instability to cause a substantial reduction of its axial stiffness;
- means for applying a compressive loading force to said elastic structure;
- and
- damping means operative with said elastic structure for providing damping to the system.
A method for increasing the vibration isolating performance of an existing vibration isolating suspension system which has positive axial stiffness and load supporting capability in an acceleration field defining an axial direction while suppressing at least some vibratory motion having a component in the axial direction between an object and base, comprising the steps of:
- operatively connecting a second suspension apparatus having means for producing negative stiffness in the axial direction between the object and base;
- and
- applying negative stiffness between the object and base to counteract the positive axial stiffness of the existing vibration isolating suspension system.
Dependencies are inferred from the claim text.