# US 2014/0152066 A1 · Failsafe magnetorheological (mr) energy absorber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0152066 A1 - Document ID: US20140152066A1 - Status: Published application - Kind: A1 - Application number: 13/916,227 - Filed: 2013-06-12 - Published: 2014-06-05 - Earliest claimed: 2012-06-12 - Assignees: Inno Vital Systems, Inc.; University of Maryland, College Park - Inventors: Gregory J. Hiemenz; Norman M. Wereley - Web page: https://patentgrep.com/patent/US20140152066A1 ## CPC - F16F 9/535: {Magnetorheological [MR] fluid dampers (springs comprising magnetorheological [MR] elastomers F16F1/361)} - B60N 2/501: {actively controlled suspension, e.g. electronic control} - B60N 2/522: {characterised by dampening means} - F16F 9/12: Devices with one or more rotary vanes turning in the fluid any throttling effect being immaterial, {i.e. damping by viscous shear effect only (F16F9/53 takes precedence; pivoting supports for apparatus or articles placed on stands or trestles F16M11/06)} - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION - B60N: SEATS SPECIALLY ADAPTED FOR VEHICLES; VEHICLE PASSENGER ACCOMMODATION NOT OTHERWISE PROVIDED FOR ## Abstract A compact and failsafe magnetorheological energy absorber design including both a light weight piston (LWP) embodiment in which linear motion is subjected to a linear damping force, and a light weight rotary vane (LWRV)embodiment in which linear motion is converted into rotary motion and is subjected to a rotary damping force. Both embodiments allow increased damper stroke within a compact mechanical profile. A new lightweight Magnetorheological energy attenuation system (LMEAS) for a vehicle seat is also disclosed using the new LMRW MREA. ## Claims ### Claim 1 A rotary vane magnetorheological energy absorber (MREA), comprising: a housing defining a sealed interior; magnetorheological fluid in the interior of said housing; a rotor mounted on a shaft inside said housing in exposure to said magnetorheological fluid; a stator body mounted stationery relative to said housing; at least one permanent magnet attached to said stator body for generating a constant baseline magnetic field in said magnetorheological fluid; electromagnetic coils wound about said stator body for generating an offset magnetic field in said magnetorheological fluid; a damping characteristic of the magnetorheological fluid on said rotor comprising a function of said constant baseline electromagnetic field and said variable offset electromagnetic field. ### Claim 2 (depends on 1) The rotary vane MREA of claim 1, further comprising a control system including non-transitory computer memory, and a programmable controller programmed with control software comprising computer instructions stored on the non-transitory computer memory for adjusting current in said electromagnetic coils to selectively increase or decrease said offset magnetic field. ### Claim 3 (depends on 1) The rotary vane MREA of claim 1, wherein said at least one permanent magnet comprises a plurality of permanent magnets. ### Claim 4 (depends on 1) The rotary vane MREA of claim 1, wherein said at least one permanent magnet comprises a circular permanent magnet. ### Claim 5 (depends on 4) The rotary vane MREA of claim 4, wherein said circular permanent magnet is embedded in said stator body. ### Claim 6 (depends on 5) The rotary vane MREA of claim 5, wherein said circular permanent magnet is seated inside an annular notch circumscribing said stator body. ### Claim 7 (depends on 5) The rotary vane MREA of claim 5, wherein said electromagnetic coils wound about said stator body are wound inside said annular notch adjacent circular permanent magnet. ### Claim 8 (depends on 2) The rotary vane MREA of claim 2, wherein said damping characteristic comprises stroking load, and said controller selectively increases said stroking load for shock absorption and selectively decreases said stroking load for vibration absorption. ### Claim 9 (depends on 8) The rotary vane MREA of claim 8, wherein said at least one permanent magnet maintains a minimum stroking load for failsafe operation when no current is supplied to said electromagnetic coils. ### Claim 10 A magnetorheological energy absorber (MREA), comprising: a housing defining a sealed interior; magnetorheological fluid within the interior of said housing; a rotor mounted on a shaft inside said housing in exposure to said magnetorheological fluid; a stator body mounted stationary relative to said housing; at least one switchable magnet attached to said stator body for generating a baseline magnetic field in said magnetorheological fluid; electromagnetic coils wound about sad stator body for generating an offset magnetic field in said magnetorheological fluid; a damping characteristic of the magnetorheological fluid on said rotor comprising a function of said constant baseline electromagnetic field and said variable offset electromagnetic field. ### Claim 11 (depends on 10) The rotary vane MREA of claim 10, further comprising a control system including non-transitory computer memory, and a programmable controller programmed with control software comprising computer instructions stored on the non-transitory computer memory for adjusting current in said electromagnetic coils to selectively increase or decrease said offset magnetic field. ### Claim 12 (depends on 10) The rotary vane MREA of claim 10, wherein said at least one switchable permanent magnet comprises a plurality of switchable permanent magnets. ### Claim 13 (depends on 12) The rotary vane MREA of claim 12, wherein said electromagnetic coils wound about said stator body are wound inside said annular notch adjacent circular permanent magnet. ### Claim 14 (depends on 11) The rotary vane MREA of claim 11, wherein said damping characteristic comprises stroking load, and said controller selectively increases said stroking load for shock absorption and selectively decreases said stroking load for vibration absorption. ### Claim 15 (depends on 14) The rotary vane MREA of claim 14, wherein said at least one permanent magnet maintains a minimum stroking load for failsafe operation when no current is supplied to said electromagnetic coils. ### Claim 16 A magnetorheological energy absorber (MREA), comprising: a housing defining a sealed interior; magnetorheological fluid within the interior of said housing; a piston body mounted inside said housing in exposure to said magnetorheological fluid; at least one permanent magnet attached to said piston body for generating a baseline magnetic field in said magnetorheological fluid; electromagnetic coils wound about said piston body for generating an offset magnetic field in said magnetorheological fluid; a damping characteristic of the magnetorheological fluid on said piston body comprising a function of said constant baseline electromagnetic field and said variable offset electromagnetic field. ### Claim 17 (depends on 16) The MREA of claim 16, further comprising a control system including non-transitory computer memory, and a programmable controller programmed with control software comprising computer instructions stored on the non-transitory computer memory for adjusting current in said electromagnetic coils to selectively increase or decrease said offset magnetic field. ### Claim 18 (depends on 16) The MREA of claim 16, wherein said at least one permanent magnet comprises a plurality of circular permanent magnets. ### Claim 19 (depends on 16) The MREA of claim 16, wherein said at least one permanent magnet comprises at least one switchable permanent magnet. ### Claim 20 (depends on 16) The MREA of claim 16, wherein said damping characteristic comprises stroking load, and said controller selectively increases said stroking load for shock absorption and selectively decreases said stroking load for vibration absorption. ### Claim 21 (depends on 20) The MREA of claim 20, wherein said at least one permanent magnet maintains a minimum stroking load for failsafe operation when no current is supplied to said electromagnetic coils. ### Claim 22 A magnetorheological seat suspension, comprising: a frame for supporting a passenger seat; a passenger seat having a yoke attached thereto, said passenger seat being movably mounted to said frame by said yoke; at least one magnetorheological energy absorber (MREA)mounted on said frame; at least one spring mounted on said frame; and at least one suspension cable running between said at least one spring and said passenger seat or yoke and engaged to said MREA. ### Claim 23 (depends on 21) The magnetorheological seat suspension according to claim 21, wherein said at least one MREA comprises a pair of MREAs mounted on said frame, said at least one spring comprises a pair of springs mounted on said frame, and said at least one suspension cable comprises a pair of suspension cables each running between a corresponding spring and said passenger seat or yoke. ### Claim 24 (depends on 1, 21) The magnetorheological seat suspension according to claim 21, wherein said MREA is a rotary vane MREA according to claim 1. ### Claim 25 (depends on 10, 21) The magnetorheological seat suspension according to claim 21, wherein said MREA is a rotary vane MREA according to claim 10.