The present invention relates generally to mountings for supporting an aerospace payload relative to a supporting structure and more particularly to a payload shock and vibration isolator.
Isolating payloads from the vibration and shock loading of a supporting structure or vehicle, or conversely isolating a structure or vehicle from an vibration inducing payload, is of concern to the aerospace industry.
U.S. Pat. No. 7,249,756 entitled “Low-profile, Multi-axis, Highly Passively Damped, Vibration Isolation Mount” is directed to a low-profile, multi-axis passively damped vibration isolation mount suitable for use in protecting hardware and payloads from damaging vibration and shock loads, particularly extreme loads seen in spacecraft launch systems.
U.S. Pat. No. 6,290,183 entitled “Three-axis, Six Degree-of-freedom, Whole-Spacecraft Passive Vibration Isolation System” is directed to a passive three-axis vibration isolation device suitable for effecting a six degree-of-freedom whole-spacecraft passive vibration isolation system.
U.S. Pat. No. 6,202,961 entitled “Passive, Multi-axis, Highly Damped, Shock Isolation Mounts for Spacecraft” is directed to a passive, multi-axis, highly damped, shock load isolation mount that serves as a one-piece mount, particularly of a spacecraft to its launch vehicle or launch vehicle adaptor structure and provides reduction in shock load transmission from a support base or structure to a payload for both axial loads and lateral loads. The disclosures of U.S. Pat. No. 7,249,756, U.S. Pat. No. 6,290,183 and U.S. Pat. No. 6,202,961 are hereby incorporated by reference in their entirety.
U.S. Pat. No. 3,721,417 entitle “Elastomeric Combination Shock and Vibration Isolator” is directed to an elastomeric mounting capable of both shock and vibration isolation comprising an elongated elastomeric tubular buckling column having one end adapted to be connected to a supporting structure.
U.S. Pat. No. 8,882,450 entitled “Device for Supporting and Securing a Piece of Equipment on an Aircraft Engine or Nacelle Case” is directed to a vibration damper that includes a first part secured to a case and a second coaxial part rigidly connected to a piece of equipment and a safety member configured to hold the damper in place in the event of a damper failure or breakage.
With parenthetical reference to the corresponding parts, portions or surfaces of the disclosed embodiment, merely for purposes of illustration and not by way of limitation, a shock and vibration isolator (15) configured to act between a support structure (18) and a payload (16) is provided comprising: a housing (19) securable to the support structure and having a rigid base portion (20), a rigid top portion (22) and a rigid side portion (21); a rigid traveler (23) orientated about a longitudinal axis (x-x); the rigid traveler disposed in the housing and configured to move axially and radially relative to the rigid base portion of the housing; the rigid traveler having a connection portion (24) attachable to the payload and a radially-extending transfer portion (25); an upper non-rigid compliant element (26) disposed axially between the top portion of the housing and the transfer portion of the rigid traveler; a lower non-rigid compliant element (28) disposed axially between the base portion of the housing and the transfer portion of the traveler; the upper non-rigid compliant element and the lower non-rigid compliant element operatively configured and arranged to selectively decouple axial motion of the payload from axial motion of the support structure; and a radial non-rigid compliant element (29) disposed radially between the side portion of the housing and the traveler and operatively configured and arranged to selectively decouple radial motion of the payload and radial motion of the support structure.
The upper non-rigid compliant element may comprise an upper spring and the lower non-rigid compliant element may comprise a lower spring. The upper and lower springs may each comprise a wave spring or a coil spring. The radially-extending transfer portion of the traveler may comprise an upper annular seat (30) retaining a first end of the upper spring and a lower annular seat (31) retaining a first end of the lower spring. The upper and lower non-rigid compliant elements may each comprise a flexure or a elastomerically deformable element. The radial non-rigid compliant element may comprise an elastomerically deformable element and the elastomerically deformable element may comprise an elastomeric O-ring. The upper and lower non-rigid compliant elements may be operatively configured and arrange to selectively decouple radial motion of the payload from radial motion of the structure. The radial non-rigid compliant element may be configured and arranged to selectively decouple axial motion of the payload from axial motion of the structure. The isolator may further comprise a fastener (32) configured and arranged to rigidly attach the base portion of the housing to the support structure and the fastener may comprise a screw. The housing may be securable to the support structure via an adhesive or a weld and the connection portion of the traveler may be attachable to the payload via an adhesive or a weld. The connection portion of the traveler may comprise a threaded opening (33) configured to receive a corresponding threaded bolt (34). The radially-extending transfer portion of the traveler may comprise an annular flange. The annular flange of the radially-extending portion of the traveler may comprise an annular groove (35) and the radial non-rigid compliant element may comprise an elastomeric O-ring disposed in the annular groove of the traveler.
In another aspect, a shock and vibration isolator configured to act between a support structure and a payload is provided comprising: a housing securable to a support structure and having a rigid base portion, a rigid top portion and a rigid side portion; a rigid traveler disposed in the housing and configured to move axially and radially relative to the rigid base portion of the support structure of the housing; the rigid traveler having a connection portion attachable to a payload and a radially-extending transfer portion; an upper non-rigid compliant element disposed axially between the top portion of the housing and the transfer portion of the rigid traveler; a lower non-rigid compliant element disposed axially between the base portion of the housing and the transfer portion of the traveler; and the upper non-rigid compliant element and the lower non-rigid compliant element operatively configured and arranged to selectively decouple axial motion of the payload from axial motion of the support structure. The isolator may further comprise a radial non-rigid compliant element disposed radially between the side portion of the housing and the traveler and operatively configured and arranged to decouple radial motion of the payload from radial motion of the structure.
At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions or surfaces consistently throughout the several drawing figures, as such elements, portions or surfaces may be further described or explained by the entire written specification, of which this detailed description is an integral part. Unless otherwise indicated, the drawings are intended to be read (e.g., crosshatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.
Referring now to the drawings, and more particularly to
As shown in
Upper spring 26, lower spring 28 and O-ring 29 between traveler 23 and housing 19 decouple both axial and radial or lateral motion of payload 16 from axial and radial or lateral motion of support structure 18 relative to longitudinal axis x-x.
As shown in
With reference to
With reference to
Surface 72 is threaded and generally defines opening 33, which receives payload bolt 34 in threaded engagement to rigidly connect payload 16 to traveler 23. A portion of surface 60 and surfaces 61 and 62 of traveler 23 generally define upper annular seat 30, which retains the lower end of upper spring 26. Similarly, surfaces 70 and 71 of traveler 23 define lower annular seat 31, which retains the upper end of spring 28. Surfaces 65, 66 and 67 of traveler 23 define annular groove 35, which retains O-ring 29. In this embodiment, the upper portion of surfaces 60 and surfaces 72 and generally define connection portion 24 of traveler 23 by which traveler 23 is affixed to payload 16. In this embodiment, surfaces 61-71 define radially-extending flange 25 of traveler 23 which supports upper spring 26, lower spring 28 and O-ring 29.
As shown in
Counter-sunk flathead screw 32 fixedly connects housing 19 to support structure 18. Screw 32 is inserted into counter-sunk hole 36 in base portion 20 of housing 19 and the threaded end of screw 32 protrudes from the bottom opening of hole 36 and engages inner threaded opening 38 of support structure 18. Screw 32 is rotated until bottom surface 42 of base 20 of housing 19 abuts and is held tightly against the top surface of support structure 18, as shown in
In this embodiment, upper and lower springs 26 and 28 are steel wave springs orientated about axis x-x. As shown in
In this embodiment, O-ring 29 is an elastomeric deformable material orientated about axis x-x. As shown in
Thus, upper spring 26 and lower spring 28 between traveler 23 and housing 19 decouple both axial and radial motion of payload 16 from axial and radial motion of support structure 18 relative to longitudinal axis x-x. O-ring 29 between traveler 23 and housing 19 decouples both axial and radial motion of payload 16 from axial and radial motion of support structure 18 relative to longitudinal axis x-x. Wave springs 26 and 28 above and below traveler 23 create axial compliance to the load path. O-ring 29 around the circumference of traveler 23 creates lateral or radial compliance and also influences the axial compliance. These elements are contained within housing 19 that is mounted to support structure 18. The relative dimensions of the components of isolator 15 may be sized to provide appropriate preload to the compliant elements 26, 28 and 29 to achieve the desired dynamic characteristics of isolator 15. Whereas wave springs are typically used to apply compressive loads and O-rings are typically used for sealing fluids, in this embodiment these elements are used in a novel manner to create a compliant load path that provides isolation to payload 16.
While wave springs and elastomeric O-rings have been shown and described, other forms of compliance may be used. For example, and without limitation, coil springs or flexures may be used instead of wave springs and radial springs or flexures may be used instead of O-rings. The housing geometry may also be altered to incorporate the invention into a larger system or smaller system or to provide increased range of motion.
Isolator 15 provides a number of unexpected benefits. Isolator 15 has a limited number of elements and provides an efficient and cost effective means for adjusting axial, radial and tip-tilt stiffness. Isolator 15 provides enhanced performance versus cost, especially for aerospace systems. Isolator 15 is a modular device that has easily tunable parameters for different applications and various material choices for different environments. Isolator 15 provides mechanical isolation and does not require the sealing of fluids and preloaded valve assemblies. Isolator 15 provides a hybrid elastomeric-friction damping approach via the O-ring and wave springs and a hybrid elastomeric-metallic stiffness approach via the O-ring and wave springs.
While the presently preferred form of the improved isolator has been shown and described, and several modifications thereof discussed, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the scope of the invention, as defined and differentiated by the claims.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/044666 | 7/29/2016 | WO | 00 |
Number | Date | Country | |
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62202628 | Aug 2015 | US |