WO2021257268A2 - Système d'amortissement des vibrations - Google Patents

Système d'amortissement des vibrations Download PDF

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Publication number
WO2021257268A2
WO2021257268A2 PCT/US2021/034894 US2021034894W WO2021257268A2 WO 2021257268 A2 WO2021257268 A2 WO 2021257268A2 US 2021034894 W US2021034894 W US 2021034894W WO 2021257268 A2 WO2021257268 A2 WO 2021257268A2
Authority
WO
WIPO (PCT)
Prior art keywords
unit
vibration dampening
dampening unit
cover
rotational
Prior art date
Application number
PCT/US2021/034894
Other languages
English (en)
Other versions
WO2021257268A3 (fr
Inventor
Salam Rahmatalla
Eric C. Frick
Charles W. HARRIS, Jr.
Varun Chalasani
Original Assignee
ActiBioMotion, LLC
University Of Iowa Research Foundation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ActiBioMotion, LLC, University Of Iowa Research Foundation filed Critical ActiBioMotion, LLC
Publication of WO2021257268A2 publication Critical patent/WO2021257268A2/fr
Publication of WO2021257268A3 publication Critical patent/WO2021257268A3/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H57/00—General details of gearing
    • F16H57/0006—Vibration-damping or noise reducing means specially adapted for gearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H57/00—General details of gearing
    • F16H57/0006—Vibration-damping or noise reducing means specially adapted for gearings
    • F16H2057/0012—Vibration-damping or noise reducing means specially adapted for gearings for reducing drive line oscillations

Definitions

  • This invention relates to systems and methods for vibration dampening of loads, and more particularly, to passive vibration dampening of loads.
  • dampening of vibrational energy is desirable for any type of load that is carried in or on a platform or vehicle.
  • the invention includes systems having a cover attached to a frame, and a transmission unit with a rotational device connected to or part of the frame.
  • the cover is mechanically connected to the at least one rotational device.
  • a vibration dampening unit mechanically connected to the transmission unit such that translational movement (e.g. vertical movements) of the cover causes rotational movement of the rotational device.
  • the rotational movement is, in turn, transmitted to the vibration dampening unit via the transmission unit.
  • the vibration dampening unit is a passive unit and also a resistance force modulated vibration dampening unit.
  • the invention also includes methods for dampening vibrations on a load which includes converting translational movement of a load to rotational movement in a transmission unit, and then transmitting the rotational movement to a vibration dampening unit, which dissipates the vibrational energy.
  • FIG. 1 shows front view of a vibration dampening system.
  • Fig. 2 shows a side view of a vibration dampening system.
  • Fig. 3 shows a view of a frictional dampening unit.
  • Fig. 4 shows a view of a fluidic dampening unit.
  • Fig. 5 shows a view of a magnetic dampening unit.
  • the invention includes a system and components, and methods, related to vibration dampening; that is, dissipation of vibrational energy.
  • the system 10 as seen in Figs. 1 and 2, is used to separate a load from a platform. While discussed in the context of the specific example of seats for humans, it is contemplated that this invention could be used to dissipate vibrational energy for an unlimited number of types of loads and platforms, and in a wide variety of situations.
  • Exemplary types of loads include animate or inanimate objects.
  • Exemplary types of platforms include land, water, amphibious, and space vehicles, as well as trailers, railcars, shipping containers, and pallets.
  • the system 10 comprises a frame 12, a cover 14, a transmission unit 16, and a vibration dampening unit 18.
  • the frame 12 serves to support the other components of the system and to anchor the system to the platform for carrying the load.
  • the frame is sized and shaped in accordance with the size, shape, weight, vibration tolerances of the load.
  • the frame includes a circumferential edge at or near the top of the frame; that is, relatively closer to load rather than the platform to which the frame is attached.
  • the cover 14 is attached to some or all of the circumferential edge of the frame in a flexible manner.
  • the purpose of the cover is to support the load when it is placed on the system by suspending the load apart from the frame or platform. Together the cover and frame provide physical separation of the load from the platform.
  • the cover is where the vehicle operator places their posterior during operation of the vehicle.
  • the cover comprises a fabric, film, or foam that is flexible, such as a woven fabric, a non-woven fabric, netting, foam layer, single or multilayered films, or a combination of these.
  • the cover preferably has a low stretch characteristic such that it stretches less than about 10% percentage when under load, however a cover with any stretch characteristic is contemplated.
  • the cover is substantially all flexible material (e.g. fabric or film).
  • the cover tends to conform to the shape of the load, e.g. a human posterior.
  • the cover also comprises a rigid or stiff portion and a flexible film portion, which flexible portion is, in turn, connected to the frame.
  • the load may be placed on the rigid portion. This would provide support to the load where it is disadvantageous to have the cover conform its shape to the load; for example, when the load is a box or crate.
  • a tensioning unit 20 is utilized in conjunction with the cover. When used, the tensioning unit connects the cover to the frame or platform and supplies tension to the cover.
  • the tensioning unit may be adjustable such that the tension on the cover can be adjusted, either before or after a load is placed on the cover. This helps insure contact of the cover to the frame or the transmission unit.
  • knobs e.g. rheostatic knobs
  • stitches e.g. electronically, mechanically, or any form of controlled tensioning units
  • the transmission unit 16 accomplishes three functions. First, it converts translational movement (e.g. vertical) into rotational movement. Thus, when the load moves up and down (as depicted by arrow 22), the cover causes the transmission to move. This up and down movement results from vibrational energy being transmitted through the platform, frame, cover, or load. Second, the transmission magnifies the displacement and speed of the rotational movement. And third, the transmission unit transmits the rotational movement to the vibration dampening unit. Of course, because of inertia of the components, and friction between the components of the transmission unit, some amount of vibrational energy is dissipated through operation of the transmission unit.
  • the transmission unit 16 connects the cover 14 to the vibration dampening unit 18.
  • the transmission unit includes at least one rotational device 24 and a linkage 26, where the linkage connects the rotational device to vibration dampening unit.
  • the at least one rotational device includes at least one roller 28, where the cover is mechanically connected to the at least one roller, either through direct contact between the cover and roller or indirectly through any of various mechanical linkages (including shafts, gears, belts, pulleys, joints, decoupling devices, and the like).
  • the cover transmits movement of the load to the roller.
  • the load moves up and down (e.g. bounces), as found when the platform vibrates, the at least one roller rotates.
  • the translational vertical movement of the load pulls on the roller and is converted to rotational movement of the at least one roller.
  • the up-down translational energy of the load is converted to rotational energy of the at least one roller.
  • the rotational device includes at least one rack and pinion system where the cover is mechanically connected to the rack, either through direct contact between the cover and rack or indirectly through any of various mechanical linkages (including shafts, gears, belts, pulleys, joints, decoupling devices, and the like). In either situation, the cover transmits movement of the load to the rack, which turns the pinion.
  • various mechanical linkages including shafts, gears, belts, pulleys, joints, decoupling devices, and the like.
  • the at least one pinion rotates.
  • the linkage preferably includes one or more gears 30, 32 to transmit the rotational movement of the rotational device to the vibration dampening unit 18.
  • a pair of different sized gears are used. In this manner, the rotational motion generated by load can be amplified. That is, use of a larger driving gear increases the angular speed of the smaller driven gear, and thus increases the transmission of rotational movement to the vibration dampening device.
  • the larger gear 30 is linked to the rotational device and the smaller gear 32 is linked to the vibration dampening unit.
  • Various additional linkages may be used as part of the transmission unit to connect the components of the transmission unit to each other or to the vibration dampening unit.
  • One preferred additional component used to connect the transmission unit to the vibration dampening unit is a decoupling device 34.
  • the decoupling device permits rotation only in one direction (e.g. clockwise).
  • the effect of the decoupling device is that the transmission unit only rotates the input (discussed below) of the vibration dampening unit during a portion of the vertical translational movement of the load or cover.
  • the downward translational movement of the load is transmitted, as rotational movement, through the transmission unit, but the upward translational movement of the load does not cause counter-rotational movement to be transmitted to the vibration dampening unit.
  • the decoupling device thus helps to isolate or decouple the operation of the cover and transmission unit from the vibration dampening unit.
  • the decoupling device also minimizes or eliminates any interference by the vibration dampening unit with the operation of the transmission unit and cover. This isolation or decoupling also minimizes or eliminates any transmittance of vibrational energy back from the vibration dampening unit and through the transmission unit.
  • any type of device may be used as the decoupling device, provided they accomplish the functionality of only allowing rotation in one direction (e.g. clockwise).
  • one-way bearings, ratchets, clutches, magnetic induction devices, friction devices (where the co-efficient of friction differs depending on the direction of rotation), etc. may be used as decoupling devices.
  • passive decoupling devices are preferred, active or semi-active device decoupling devices may also be utilized. While preferably used in at least the location where the transmission unit connects to the vibration dampening unit, the decoupling device may be used elsewhere in the transmission unit. Using a plurality of decoupling units is also contemplated.
  • the transmission unit may also include a spring 36 (e.g. a torsional spring) or other device to counteract the rotational movement of the rotational device or the gears in the transmission unit.
  • the spring acts on the rotational device or gear to return the rotational device to a starting or reset position so that the rotational device is again able to transmit vertical translational movement to the transmission unit and the vibration dampening unit.
  • the rotational device rotates.
  • the spring provides a counteracting force to counter-rotate the rotational device, and thus resetting the rotational device.
  • the spring accomplishes the same function as the tensioning unit; i.e.
  • the use of the decoupling unit in combination with the spring facilitates this counter-rotation because the spring is not attempting to counter-rotate the input (discussed below) of the vibration dampening unit.
  • the vibration dampening 18 unit functions to dissipate the movement transmitted from the cover through the transmission unit.
  • a frictional dampening unit uses friction, through direct contact of adjacent plates, to dissipate the vibrational energy. That is vibrational energy is dissipated as heat through friction.
  • a fluidic dampening unit uses liquids or gases to dissipate the vibrational energy. That is, vibrational energy is dissipated as heat generated through the viscous shearing of a gas or liquid.
  • a magnetic dampening unit uses opposing magnetic fields to dissipate the vibrational energy. That is, vibrational energy is dissipated, for example, by eddy current dampening as magnets move through opposing magnetic fields.
  • Each embodiment of the vibration dampening unit preferably achieves the same functional characteristics in that there a correlation between the size of the vertical translation movement and the resistance provided by the vibration dampening unit.
  • This correlation may be linear or non-linear.
  • the non-linear correlation typically means that resistance force increases faster than linearly.
  • This non-linear correlation is called resistance force modulation, and is preferred. Meaning that for small vertical movements, the resistance forces will be small (e.g. a small coefficient of friction). And that for larger vertical movements, the resistance forces will be larger.
  • small vertical movements will result is a small coefficient of friction and larger vertical movements will result in a higher coefficient of friction between the input and dissipation unit (as discussed below).
  • a non-Newtonian fluid would provide a non-linear correlation between the vertical translation movement and the resistance provided by the vibration dampening unit. Similar non-linear correlation between the vertical translation movement and the resistance provided by the magnetic vibration dampening unit.
  • Resistance force modulated vibration dampening units permit the system to dissipate vibrational energy over a wide range of vertical movements of the load.
  • Each dampening unit comprises an input 38, mechanically connected to the transmission unit, and a dissipation unit 40.
  • the input and dissipation unit work cooperatively to dissipate the vibrational energy.
  • the input for the frictional dampening unit may include at least one friction surface that has a surface that will rub against a surface of the dissipation unit.
  • the friction surface is a first circular plate and the dissipation unit includes one or more second friction surface that are also circular plates.
  • the rotational movement transmitted through the transmission unit rotates the first friction plate and it rubs against the second friction plate.
  • the first friction plate attached to a shaft connected to the smaller gear in the transmission unit. In this way, the frictional dampening unit dissipates the vibrational energy from the load. Any pair of complementary friction surfaces may be used.
  • Each of the friction surfaces may have a uniform roughness or the roughness may vary across the surface.
  • the roughness of the friction surface changes as the radial distance increases.
  • the coefficient of friction for the surface could increase (or decrease) as the distance from the center (axis of rotational) of the surfaces increases; that is, as the radial distance increases.
  • the roughness may fluctuate as the radial distance increases.
  • Friction surfaces may be of consistent roughness or patterns of varying roughness on their surfaces.
  • the dissipation unit may comprise a plurality of friction surfaces (e.g. multiple plates) with multiple surfaces (e.g. front and back of the plate) that have the same or different roughness.
  • the resistance force modulation is achieved by allowing a first friction plate 42 to rub on a second friction plate 44 such that the first friction plate will slide radially from the center of the second friction plate toward its edge as the vertical translation movement of the load increases. This may be accomplished by moving the second friction plate and holding the first friction plate steady, or vice versa.
  • the variability of the coefficient of friction on the second friction plate is denoted by the words low, medium, and high.
  • the slide of the friction plates is accomplished with a pair of gears 46, 48 and a carriage screw 49 for the second friction plate, which moves the second friction plate along an axis of rotation of gear 48, that is, axially.
  • Resistance force modulation can also be achieved by applying external pressure to two adjacent friction plates to cause a higher coefficient of friction between the plates, where the applied external pressure is proportional to the vertical translation movement.
  • the fluidic dampening unit utilizes fluids, including liquids, gases, and combinations as part of the dissipation of vibration energy.
  • the input for the fluidic dampening unit comprising a propeller 50 or other 3D shape
  • dissipation unit comprises a reservoir 52 for a fluid.
  • the fluid in the reservoir resists the motion of the input, thus dissipating the vibrational energy, with fluids having a higher viscosity providing more resistance.
  • a variety of shapes, types, number of propellers may be utilized for the input.
  • the fluid in the reservoir may be selected based on viscosity or other characteristic (e.g. environmental compatibility or inertness).
  • the resistance provided by the fluid may be static or adjustable, so as to temporarily or permanently change the vibrational energy dissipation characteristics of the fluidic dampening unit.
  • the magnetic dampening unit utilizes one or more magnetic fields as part of the dissipation of vibration energy.
  • physical contact either between friction plates or between a fluid and its container
  • the input has a first magnetic field, however created, and the dissipation unit has a second, opposing magnet field, however created.
  • the input may include a first magnet 54 and the dissipation unit may include a second magnet 56.
  • the rotational movement transmitted through the transmission unit rotates the first magnetic field and this is resisted by the second magnetic field.
  • the movement of the magnet fields dissipates the vibrational energy.
  • One such phenomenon is eddy current dampening.
  • the strength of the one or more magnetic fields may be static or adjustable, so as to temporarily or permanently change the vibrational energy dissipation characteristics of the magnetic dampening unit.
  • the vibration dampening unit is passive in that it does not utilize an external power source to provide the vibration dampening or energy dissipation.
  • an external power source may not provide vibration dampening directly, but rather may adjust the vibration dampening characteristics of the vibration dampening unit.
  • an external power source may be used to increase the pressure between adjacent frictional plates.
  • the external power source may be used to increase the pressure on the fluid in the reservoir, thus increasing the energy dissipation of the unit.
  • the external power source may be used to increase the strength of the magnetic fields, thus increasing the energy dissipation of the unit.
  • external power sources may be utilized to adjust other components of the system such as the tensioning unit or the spring of the transmission unite.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Vibration Prevention Devices (AREA)

Abstract

L'invention comprend des systèmes ayant un couvercle fixé à un cadre et une unité de transmission avec un dispositif rotatif relié à une partie du cadre ou formant une partie de ce dernier. Le couvercle est relié mécaniquement au ou aux dispositifs rotatifs. Une unité d'amortissement des vibrations est reliée mécaniquement à l'unité de transmission de telle sorte qu'un mouvement de translation (par exemple des mouvements verticaux) du couvercle provoque un mouvement de rotation du dispositif rotatif. Le mouvement de rotation est, à son tour, transmis à l'unité d'amortissement de vibrations par l'intermédiaire de l'unité de transmission. De préférence, l'unité d'amortissement des vibrations est une unité passive et également une unité d'amortissement des vibrations modulée par une force de résistance. L'invention concerne également des procédés pour amortir des vibrations sur une charge qui comprend la conversion d'un mouvement de translation d'une charge en un mouvement de rotation dans une unité de transmission, la transmission agrandissant le déplacement et la vitesse du mouvement de rotation, puis transmettant le mouvement de rotation à une unité d'amortissement de vibrations, qui dissipe l'énergie de vibration.
PCT/US2021/034894 2020-05-28 2021-05-28 Système d'amortissement des vibrations WO2021257268A2 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US202017333464A 2020-05-28 2020-05-28
US17/333,464 2020-05-28
US202063031758P 2020-05-29 2020-05-29
US63/031,758 2020-05-29

Publications (2)

Publication Number Publication Date
WO2021257268A2 true WO2021257268A2 (fr) 2021-12-23
WO2021257268A3 WO2021257268A3 (fr) 2022-02-10

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Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0616746U (ja) * 1992-07-27 1994-03-04 石川島播磨重工業株式会社 磁力式制振装置
JP2000074135A (ja) * 1998-08-28 2000-03-07 Daiwa House Ind Co Ltd 制振構造及び制振装置
US6416127B1 (en) * 2000-10-26 2002-07-09 Lear Corporation Oscillating damped energy management device
JP2005009565A (ja) * 2003-06-18 2005-01-13 Tokkyokiki Corp 振動減衰装置
JP5705618B2 (ja) * 2011-03-30 2015-04-22 中日本高速道路株式会社 振動発電装置

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