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Thursday, 1 December 2011

INTRODUCTION TO MAGNETIC SHOCK ABSORBERS


INTRODUCTION TO MAGNETIC SHOCK ABSORBERS

THE IDEA FOR A MAGNETIC SHOCK ABSORBER (FOR AUTOMOBILES AND TWO-WHEELERS), MAKES USE OF THE MAGNETIC REPULSION BETWEEN DIPOLES TO ACHIEVE SHOCK ABSORPTION. OFTEN WHEN RIDING ON HER TWO-WHEELER WE USED TO FACE SOME PROBLEMS WHILE MOVING ON THE BUMPY ROAD DUE TO ITS UNEVENNESS.
IT OBSERVED THAT THE LIKE POLES OF TWO MAGNETS OF THE SAME PROPERTIES AND STRENGTH REPULSE EACH OTHER AND THEY KEEP A CONSTANT DISTANCE BETWEEN EACH OTHER BECAUSE OF THEIR MAGNETIC FIELDS. THIS MADE HER THINK THAT IF THE SHOCK ABSORBERS ARE MADE OF MAGNETS WITH SIMILAR POLES FACING EACH OTHER, IT MAY GIVE BETTER PERFORMANCE AND NO MAINTENANCE WOULD BE REQUIRED FOR THE SAME.
THE UNIT COMPRISES OF TWO CIRCULAR MAGNETS AND A ROD (STRAIGHT CYLINDRICAL ROD WHICH CAN BE USED AS AXLE). ONE MAGNET IS ATTACHED AT THE BOTTOM OF THE ROD AND IS THE BASE MAGNET. THE OTHER MAGNET IS FREE, WITH A FLOAT AND HAS THE SIMILAR POLE PLACED TOWARDS THE BASE MAGNET. THE SIMILARITY OF POLES CREATES REPULSION AND A CERTAIN DISTANCE IS MAINTAINED. AS PER LOAD CONDITION, THE FLOATING MAGNET MOVES AND CLOSES THE GAP UNTIL THE MAGNETIC REPULSION IS STRONG ENOUGH TO CREATE THE DAMPING ACTION. IN THIS MANNER A SHOCK ABSORBER WITHOUT SPRINGS WORKING ON THE BASIC LAW OF MAGNETS -OPPOSITE POLES ATTRACT AND SIMILAR POLES REPEL- IS PREPARED.
ADVANTAGES

THIS SHOCK ABSORBER WILL ERADICATE THE PROBLEMS FACED IN THE SPRING SHOCK ABSORBERS DUE TO FRICTION AND OTHER FACTORS. THIS WILL ALSO REDUCE THE MAINTENANCE COSTS AS IT DOES NOT NEED REPAIRING, CHANGING OF SPRINGS OR DEALING WITH LEAKAGE PROBLEMS AS IN SPRING OR OIL SHOCK ABSORBERS. THIS MAGNETIC SHOCK ABSORBER CAN BE USED IN VEHICLES CARRYING HEAVY OR LESS LOAD. IMPROVING ON HER CONCEPT SHE SAYS THAT TO MAKE THESE MAGNETIC SHOCK ABSORBERS EVEN BETTER, A CHAIN OF MORE THAN TWO MAGNETS CAN BE USED TO TOLERATE THE SHOCKS OR WEIGHT AND MAKE THE VEHICLE MORE COMFORTABLE.


SHOCK ABSORBERS

A SHOCK ABSORBER IN COMMON PARLANCE (OR DAMPER IN TECHNICAL USE) IS A MECHANICAL DEVICE DESIGNED TO SMOOTH OUT OR DAMP SUDDEN SHOCK IMPULSE AND DISSIPATE KINETIC ENERGY. IT IS ANALOGOUS TO A RESISTOR IN AN ELECTRIC RLC CIRCUIT.
SHOCK ABSORBERS MUST ABSORB OR DISSIPATE ENERGY. ONE DESIGN CONSIDERATION, WHEN DESIGNING OR CHOOSING A SHOCK ABSORBER IS WHERE THAT ENERGY WILL GO. IN MOST DASHPOTS, ENERGY IS CONVERTED TO HEAT INSIDE THE VISCOUS FLUID. IN HYDRAULIC CYLINDERS, THE HYDRAULIC FLUID WILL HEAT UP. IN AIR CYLINDERS, THE HOT AIR IS USUALLY EXHAUSTED TO THE ATMOSPHERE. IN OTHER TYPES OF DASHPOTS, SUCH AS ELECTROMAGNETIC ONES, THE DISSIPATED ENERGY CAN BE STORED AND USED LATER.
SHOCK ABSORBERS ARE AN IMPORTANT PART OF AUTOMOBILE AND MOTORCYCLE SUSPENSIONS, AIRCRAFT LANDING GEAR, AND THE SUPPORTS FOR MANY INDUSTRIAL MACHINES. LARGE SHOCK ABSORBERS HAVE ALSO BEEN USED IN STRUCTURAL ENGINEERING TO REDUCE THE SUSCEPTIBILITY OF STRUCTURES TO EARTHQUAKE DAMAGE AND RESONANCE.
SHOCK ABSORBERS, LINEAR DAMPERS, AND DASHPOTS ARE DEVICES DESIGNED TO PROVIDE ABSORPTION OF SHOCK AND SMOOTH DECELERATION IN LINEAR MOTION APPLICATIONS. THEY MAY BE MECHANICAL (E.G., ELASTOMERIC OR COIL SPRING) OR RELY ON A FLUID (GAS, AIR, HYDRAULIC), WHICH ABSORBS SHOCK BY ALLOWING CONTROLLED FLOW FROM OUTER TO INNER CHAMBER OF A CYLINDER DURING PISTON ACTUATION. IN CONVENTIONAL SHOCK ABSORBERS THE PISTON ROD IS TYPICALLY RETURNED TO THE UNLOADED POSITION WITH A SPRING. SHOCK ABSORBERS TYPICALLY CONTAIN EITHER A FLUID OR MECHANICAL DAMPENING SYSTEM AND A RETURN MECHANISM TO THE UNENGAGED POSITION. THEY VARY FROM SMALL DEVICE APPLICATION TO LARGE INDUSTRIAL AND CIVIL ENGINEERING USES. LINEAR DAMPERS IS AN INCLUSIVE TERM THAT CAN BE APPLIED TO MANY FORMS OF DASHPOTS AND SHOCK ABSORBERS; TYPICALLY USED FOR DEVICES DESIGNED PRIMARILY FOR RECIPROCATING MOTION ATTENUATION RATHER THAN ABSORPTION OF LARGE SHOCK LOADS. DASHPOTS ARE TYPICALLY DISTINCT IN THAT WHILE THEY USE CONTROLLED FLUID FLOW TO DAMPEN AND DECELERATE MOTION, THEY DO NOT NECESSARILY INCORPORATE AN INTEGRAL RETURN MECHANISM SUCH AS A SPRING. DASHPOTS ARE OFTEN RELATIVELY SMALL, PRECISE DEVICES USED FOR APPLICATIONS SUCH AS INSTRUMENTATION AND PRECISION MANUFACTURING.

SHOCK ABSORBERS OR DAMPER TYPES FOR SHOCK ABSORBERS, LINEAR DAMPERS AND DASHPOTS CAN BE HYDRAULIC, AIR, GAS SPRING, OR ELASTOMERIC. THE ABSORPTION OR DAMPING ACTION CAN BE COMPRESSION OR EXTENSION. IMPORTANT PARAMETERS TO CONSIDER WHEN SEARCHING FOR SHOCK ABSORBERS, LINEAR DAMPERS AND DASHPOTS INCLUDE ABSORBER STROKE, COMPRESSED LENGTH, EXTENDED LENGTH, MAXIMUM FORCE (P1), AND MAXIMUM CYCLES PER MINUTE. ABSORBER OR SPRING STROKE IS DIFFERENCE BETWEEN FULLY EXTENDED AND FULLY COMPRESSED POSITION. COMPRESSED LENGTH IS THE MINIMUM LENGTH OF SHOCK (COMPRESSED POSITION). EXTENDED LENGTH IS THE MAXIMUM LENGTH OF SHOCK (EXTENDED POSITION). THE MAXIMUM RATED FORCE FOR SHOCK ABSORBER OR DAMPER, REFERRED TO AS THE P1 FORCE. THE MAXIMUM CYCLES PER MINUTE ARE THE RATED FREQUENCY OF COMPRESSION/EXTENSION CYCLES.

IMPORTANT PHYSICAL SPECIFICATIONS TO CONSIDER WHEN SEARCHING SHOCK ABSORBERS, LINEAR DAMPERS AND DASHPOTS INCLUDE THE CYLINDER DIAMETER OR MAXIMUM WIDTH, THE ROD DIAMETER, MOUNTING, AND BODY MATERIAL. THE CYLINDER DIAMETER OR MAXIMUM WIDTH REFERS TO THE DESIRED DIAMETER OF HOUSING CYLINDER. THE ROD DIAMETER REFERS TO THE DESIRED DIAMETER OF EXTENDING ROD. MOUNTING CHOICES INCLUDE BALL AND SOCKET, ROD END, CLEVIS, EYELET, TAPERED END, THREADED, AND BUMPER OR ROD END UNATTACHED. CHOICES FOR BODY MATERIALS INCLUDE ALUMINUM, STEEL, STAINLESS STEEL, AND THERMOPLASTIC. COMMON FEATURES FOR SHOCK ABSORBERS, LINEAR DAMPERS AND DASHPOTS INCLUDE ADJUSTABLE CONFIGURATION, REDUCIBLE, LOCKING, AND VALVE. AN ADJUSTABLE CONFIGURATION ALLOWS THE USER TO FINE TUNE DESIRED DAMPING, EITHER CONTINUOUSLY OR AT DISCRETE SETTINGS. A REDUCIBLE SHOCK ABSORBER, LINEAR DAMPER OR DASHPOT HAS AN ADJUSTMENT STYLE FOR GAS SHOCKS IN WHICH GAS IS LET OUT TO PERMANENTLY REDUCE FORCE CAPACITY. IN A LOCKING CONFIGURATION THE POSITION CAN BE LOCKED AT ENDS OR IN THE MIDDLE OF STROKE. VALVES CAN BE INCLUDED FOR FLUID ABSORBERS, A VALVE OR PORT, WHICH CAN BE USED TO INCREASE OR DECREASE FLUID VOLUME OR PRESSURE.


USES OF SHOCK ABSORBERS

VEHICLES SUSPENSION

IN A VEHICLE, IT REDUCES THE EFFECT OF TRAVELING OVER ROUGH GROUND, LEADING TO IMPROVED RIDE QUALITY. WITHOUT SHOCK ABSORBERS, THE VEHICLE WOULD HAVE A BOUNCING RIDE, AS ENERGY IS STORED IN THE SPRING AND THEN RELEASED TO THE VEHICLE, POSSIBLY EXCEEDING THE ALLOWED RANGE OF SUSPENSION MOVEMENT. CONTROL OF EXCESSIVE SUSPENSION MOVEMENT WITHOUT SHOCK ABSORPTION REQUIRES STIFFER (HIGHER RATE) SPRINGS, WHICH WOULD IN TURN GIVE A HARSH RIDE. SHOCK ABSORBERS ALLOW THE USE OF SOFT (LOWER RATE) SPRINGS WHILE CONTROLLING THE RATE OF SUSPENSION MOVEMENT IN RESPONSE TO BUMPS. THEY ALSO, ALONG WITH HYSTERESIS IN THE TIRE ITSELF, DAMP THE MOTION OF THE UNSPRUNG WEIGHT UP AND DOWN ON THE SPRINGINESS OF THE TIRE. SINCE THE TIRE IS NOT AS SOFT AS THE SPRINGS, EFFECTIVE WHEEL BOUNCE DAMPING MAY REQUIRE STIFFER SHOCKS THAN WOULD BE IDEAL FOR THE VEHICLE MOTION ALONE.
SPRING-BASED SHOCK ABSORBERS COMMONLY USE COIL SPRINGS ORLEAF SPRINGS, THOUGH TORSION BARS CAN BE USED IN TORSIONAL SHOCKS AS WELL. IDEAL SPRINGS ALONE, HOWEVER, ARE NOT SHOCK ABSORBERS AS SPRINGS ONLY STORE AND DO NOT DISSIPATE OR ABSORB ENERGY. VEHICLES TYPICALLY EMPLOY BOTH SPRINGS OR TORSION BARS AS WELL AS HYDRAULIC SHOCK ABSORBERS. IN THIS COMBINATION, "SHOCK ABSORBER" IS RESERVED SPECIFICALLY FOR THE HYDRAULIC PISTON THAT ABSORBS AND DISSIPATES VIBRATION.
STRUCTURES
APPLIED TO A STRUCTURE SUCH AS A BUILDING OR BRIDGEIT MAY BE PART OF A SEISMIC RETROFIT OR AS PART OF NEW EARTHQUAKE RESISTANT CONSTRUCTION. IN THIS APPLICATION IT ALLOWS YET RESTRAINS MOTION AND ABSORBSRESONANT ENERGY, WHICH CAN CAUSE EXCESSIVE MOTION AND EVENTUALSTRUCTURAL FAILURE.


DIFFERENT SHOCK ABSORBERS IN USE
THERE ARE SEVERAL COMMONLY-USED APPROACHES TO SHOCK ABSORPTION:
  • HYSTERSIS OF STRUCTURAL MATERIAL, FOR EXAMPLE THE COMPRESSION OF RUBBER DISKS, STRETCHING OF RUBBER BANDS AND CORDS, BENDING OFSTEEL SPRINGS, OR TWISTING OF TORSION BARS. HYSTERESIS IS THE TENDENCY FOR OTHERWISE ELASTIC MATERIALS TO REBOUND WITH LESS FORCE THAN WAS REQUIRED TO DEFORM THEM. SIMPLE VEHICLES WITH NO SEPARATE SHOCK ABSORBERS ARE DAMPED, TO SOME EXTENT, BY THE HYSTERESIS OF THEIR SPRINGS AND FRAMES.
  • DRY FRICTION AS USED IN WHEEL BRAKES, BY USING DISKS (CLASSICALLY MADE OF LEATHER) AT THE PIVOT OF A LEVER, WITH FRICTION FORCED BY SPRINGS. USED IN EARLY AUTOMOBILES. ALTHOUGH NOW CONSIDERED OBSOLETE, AN ADVANTAGE OF THIS SYSTEM IS ITS MECHANICAL SIMPLICITY; THE DEGREE OF DAMPING CAN BE EASILY ADJUSTED BY TIGHTENING OR LOOSENING THE SCREW CLAMPING THE DISKS, AND IT CAN BE EASILY REBUILT WITH SIMPLE HAND TOOLS. A DISADVANTAGE IS THAT THE DAMPING FORCE TENDS NOT TO INCREASE WITH THE SPEED OF THE VERTICAL MOTION.
  • SOLID STATE, TAPERED CHAIN SHOCK ABSORBERS, USING ONE OR MORE TAPERED, AXIAL ALIGNMENT(S) OF GRANULAR SPHERES, TYPICALLY MADE OF METALS SUCH AS NITINOL, IN A CASING.
  • FLUID FRICTION, FOR EXAMPLE THE FLOW OF FLUID THROUGH A NARROW ORIFICE (HYDRAULICS), CONSTITUTE THE VAST MAJORITY OF AUTOMOTIVE SHOCK ABSORBERS. AN ADVANTAGE OF THIS TYPE IS THAT USING SPECIAL INTERNAL VALVING THE ABSORBER MAY BE MADE RELATIVELY SOFT TO COMPRESSION (ALLOWING A SOFT RESPONSE TO A BUMP) AND RELATIVELY STIFF TO EXTENSION, CONTROLLING “JOUNCE”, WHICH IS THE VEHICLE RESPONSE TO ENERGY STORED IN THE SPRINGS; SIMILARLY, A SERIES OF VALVES CONTROLLED BY SPRINGS CAN CHANGE THE DEGREE OF STIFFNESS ACCORDING TO THE VELOCITY OF THE IMPACT OR REBOUND. SOME SHOCK ABSORBERS ALLOW TUNING OF THE RIDE VIA CONTROL OF THE VALVE BY A MANUAL ADJUSTMENT PROVIDED AT THE SHOCK ABSORBER. IN MORE EXPENSIVE VEHICLES THE VALVES MAY BE REMOTELY ADJUSTABLE, OFFERING THE DRIVER CONTROL OF THE RIDE AT WILL WHILE THE VEHICLE IS OPERATED. THE ULTIMATE CONTROL IS PROVIDED BY DYNAMIC VALVE CONTROL VIA COMPUTER IN RESPONSE TO SENSORS, GIVING BOTH A SMOOTH RIDE AND A FIRM SUSPENSION WHEN NEEDED. MANY SHOCK ABSORBERS CONTAIN COMPRESSED NITROGEN, TO REDUCE THE TENDENCY FOR THE OIL TO FOAM UNDER HEAVY USE. FOAMING TEMPORARILY REDUCES THE DAMPING ABILITY OF THE UNIT. ANOTHER VARIATION IS THE MAGNETO RHEOLOGICAL DAMPER WHICH CHANGES ITS FLUID CHARACTERISTICS THROUGH AN ELECTROMAGNET.
  • COMPRESSION OF A GAS, FOR EXAMPLE PNEUMATIC SHOCK ABSORBERS, WHICH CAN ACT LIKE SPRINGS AS THE AIR PRESSURE IS BUILDING TO RESIST THE FORCE ON IT. ONCE THE AIR PRESSURE REACHES THE NECESSARY MAXIMUM, AIR DASHPOTS WILL ACT LIKE HYDRAULIC DASHPOTS. IN AIRCRAFT LANDING GEAR AIR DASHPOTS MAY BE COMBINED WITH HYDRAULIC DAMPING TO REDUCE BOUNCE. SUCH STRUTS ARE CALLED OLEO STRUTS(COMBINING OIL AND AIR).
  • MAGNETIC EFFECTS. EDDY CURRENT DAMPERS ARE DASHPOTS THAT ARE CONSTRUCTED OUT OF A LARGE MAGNET INSIDE OF A NON-MAGNETIC, ELECTRICALLY CONDUCTIVE TUBE.
  • INERTIAL RESISTANCE TO ACCELERATION, FOR EXAMPLE PRIOR TO 1966 THE CITROEN 2CV HAD SHOCK ABSORBERS THAT DAMP WHEEL BOUNCE WITH NO EXTERNAL MOVING PARTS. THESE CONSISTED OF A SPRING-MOUNTED 3.5 KG (7.75 LB) IRON WEIGHT INSIDE A VERTICAL CYLINDER AND ARE SIMILAR TO, YET MUCH SMALLER THAN VERSIONS OF THE TUNED MASS DAMPERS USED ON TALL BUILDINGS
  • COMPOSITE HYDROPNEUMATIC DEVICES WHICH COMBINE IN A SINGLE DEVICE SPRING ACTION, SHOCK ABSORPTION, AND OFTEN ALSO RIDE-HEIGHT CONTROL, AS IN SOME MODELS OF THE CITROEN AUTOMOBILE.
  • CONVENTIONAL SHOCK ABSORBERS COMBINED WITH COMPOSITE PNEUMATIC SPRINGS WITH WHICH ALLOW RIDE HEIGHT ADJUSTMENT OR EVEN RIDE HEIGHT CONTROL, SEEN IN SOME LARGE TRUCKS AND LUXURY SEDANS SUCH AS CERTAIN LINCOLN AND MOST LAND ROVER AUTOMOBILES. RIDE HEIGHT CONTROL IS ESPECIALLY DESIRABLE IN HIGHWAY VEHICLES INTENDED FOR OCCASIONAL ROUGH ROAD USE, AS A MEANS OF IMPROVING HANDLING AND REDUCING AERODYNAMIC DRAG BY LOWERING THE VEHICLE WHEN OPERATING ON IMPROVED HIGH SPEED ROADS.
  • THE EFFECT OF A SHOCK ABSORBER AT HIGH (SOUND) FREQUENCIES IS USUALLY LIMITED BY USING A COMPRESSIBLE GAS AS THE WORKING FLUID AND/OR MOUNTING IT WITH RUBBER BUSHINGS.

A BRIEF HISTORY

IN THE EARLY 1900’S, CARS STILL RODE ON CARRIAGE SPRINGS. AFTER ALL, EARLY DRIVERS HAD BIGGER THINGS TO WORRY ABOUT THAN THE QUALITY OF THEIR RIDE – LIKE KEEPING THEIR CARS ROLLING OVER THE ROCKS AND RUTS THAT OFTEN PASSED FOR ROADS.
PIONEERING VEHICLE MANUFACTURERS WERE FACED EARLY ON WITH THE CHALLENGES OF ENHANCING DRIVER CONTROL AND PASSENGER COMFORT. THESE EARLY SUSPENSION DESIGNS FOUND THE FRONT WHEELS ATTACHED TO THE AXLE USING STEERING SPINDLES AND KINGPINS. THIS ALLOWED THE WHEELS TO PIVOT WHILE THE AXLE REMAINED STATIONARY. ADDITIONALLY, THE UP AND DOWN OSCILLATION OF THE LEAF SPRING WAS DAMPED BY DEVICE CALLED A SHOCK ABSORBER.
THESE FIRST SHOCK ABSORBERS WERE SIMPLY TWO ARMS CONNECTED BY A BOLT WITH A FRICTION DISK BETWEEN THEM. RESISTANCE WAS ADJUSTED BY TIGHTENING OR LOOSENING THE BOLT.

AS MIGHT BE EXPECTED, THE SHOCKS WERE NOT VERY DURABLE, AND THE PERFORMANCE LEFT MUCH TO BE DESIRED. OVER THE YEARS, SHOCK ABSORBERS HAVE EVOLVED INTO MORE SOPHISTICATED DESIGNS.
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WHAT SHOCKS DO ?
LET’S START OUR DISCUSSION OF SHOCK ABSORBERS WITH ONE OF VERY IMPORTANT POINT: DESPITE WHAT MANY PEOPLE THINK, CONVENTIONAL SHOCK ABSORBERS DO NOT SUPPORT VEHICLE WEIGHT. INSTEAD, THE PRIMARY PURPOSE OF THE SHOCK ABSORBER IS TO CONTROL SPRING AND SUSPENSION MOVEMENT. THIS IS ACCOMPLISHED BY TURNING THE KINETIC ENERGY OF SUSPENSION MOVEMENT INTO THERMAL ENERGY, OR HEAT ENERGY, TO BE DISSIPATED THROUGH THE HYDRAULIC FLUID.

SHOCK ABSORBERS ARE BASICALLY OIL PUMPS. A PISTON IS ATTACHED TO THE END OF THE PISTON ROD AND WORKS AGAINST HYDRAULIC FLUID IN THE PRESSURE TUBE. AS THE SUSPENSION TRAVELS UP AND DOWN, THE HYDRAULIC FLUID IS FORCED THROUGH TINY HOLES, CALLED ORIFICES, INSIDE THE PISTON. HOWEVER, THESE ORIFICES LET ONLY A SMALL AMOUNT OF FLUID THROUGH THE PISTON. THIS SLOWS DOWN THE PISTON, WHICH IN TURN SLOWS DOWN SPRING AND SUSPENSION MOVEMENT.

THE AMOUNT OF RESISTANCE A SHOCK ABSORBER DEVELOPS DEPENDS ON THE SPEED OF THE SUSPENSION AND THE NUMBER AND SIZE OF THE ORIFICES IN THE PISTON. ALL MODERN SHOCK ABSORBERS ARE VELOCITY SENSITIVE HYDRAULIC DAMPING DEVICES – MEANING THE FASTER THE SUSPENSION MOVES, THE MORE RESISTANCE THE SHOCK
ABSORBER PROVIDES. BECAUSE OF THIS FEATURE, SHOCK ABSORBERS ADJUST TO ROAD CONDITIONS. AS A RESULT, SHOCK ABSORBERS REDUCE THE RATE OF:
  • BOUNCE
  • ROLL OR SWAY
  • BRAKE DIVE AND ACCELERATION SQUAT
SHOCK ABSORBERS WORK ON THE PRINCIPLE OF FLUID DISPLACEMENT ON BOTH THE COMPRESSION AND EXTENSION CYCLE. A TYPICAL CAR OR LIGHT TRUCK WILL HAVE MORE RESISTANCE DURING ITS EXTENSION CYCLE THEN ITS COMPRESSION CYCLE. THE COMPRESSION CYCLE CONTROLS THE MOTION OF A VEHICLE’S UNSPRUNG WEIGHT, WHILE EXTENSION CONTROLS THE HEAVIER SPRUNG WEIGHT.



WORKING OF SHOCK ABSORBERS

SHOCK ABSORBERS WORK IN TWO CYCLES -- THE COMPRESSION CYCLE AND THE EXTENSION CYCLE. THE COMPRESSION CYCLE OCCURS AS THE PISTON MOVES DOWNWARD, COMPRESSING THE HYDRAULIC FLUID IN THE CHAMBER BELOW THE PISTON. THE EXTENSION CYCLE OCCURS AS THE PISTON MOVES TOWARD THE TOP OF THE PRESSURE TUBE, COMPRESSING THE FLUID IN THE CHAMBER ABOVE THE PISTON. A TYPICAL CAR OR LIGHT TRUCK WILL HAVE MORE RESISTANCE DURING ITS EXTENSION CYCLE THAN ITS COMPRESSION CYCLE. WITH THAT IN MIND, THE COMPRESSION CYCLE CONTROLS THE MOTION OF THE VEHICLE'S UNSPRUNG WEIGHT, WHILE EXTENSION CONTROLS THE HEAVIER, SPRUNG WEIGHT.

COMPRESSION CYCLE

DURING THE COMPRESSION STROKE OR DOWNWARD MOVEMENT, SOME FLUID FLOWS THROUGH THE PISTON FROM CHAMBER B TO CHAMBER A AND SOME THROUGH THE COMPRESSION VALVE INTO THE RESERVE TUBE. TO CONTROL THE FLOW, THERE ARE THREE VALVING STAGES EACH IN THE PISTON AND IN THE COMPRESSION VALVE.
AT THE PISTON, OIL FLOWS THROUGH THE OIL PORTS, AND AT SLOW PISTON SPEEDS, THE FIRST STAGE BLEEDS COME INTO PLAY AND RESTRICT THE AMOUNT OF OIL FLOW. THIS ALLOWS A CONTROLLED FLOW OF FLUID FROM CHAMBER B TO CHAMBER A.

AT FASTER PISTON SPEEDS, THE INCREASE IN FLUID PRESSURE BELOW THE PISTON IN CHAMBER B CAUSES THE DISCS TO OPEN UP AWAY FROM THE VALVE SEAT.

AT HIGH SPEEDS, THE LIMIT OF THE SECOND STAGE DISCS PHASES INTO THE THIRD STAGE ORIFICE RESTRICTIONS. COMPRESSION CONTROL, THEN, IS THE FORCE THAT RESULTS FROM A HIGHER
PRESSURE PRESENT IN CHAMBER B, WHICH ACTS ON THE BOTTOM OF THE PISTON AND THE PISTON ROD AREA.


EXTENSION CYCLE

AS THE PISTON AND ROD MOVE UPWARD TOWARD THE TOP OF THE PRESSURE TUBE, THE VOLUME OF CHAMBER A IS REDUCED AND THUS IS AT A HIGHER PRESSURE THAN CHAMBER B. BECAUSE OF THIS HIGHER PRESSURE, FLUID FLOWS DOWN THROUGH THE PISTON’S 3-STAGE EXTENSION VALVE INTO CHAMBER B.

HOWEVER, THE PISTON ROD VOLUME HAS BEEN WITHDRAWN FROM CHAMBER B GREATLY INCREASING ITS VOLUME. THUS THE VOLUME OF FLUID FROM CHAMBER A IS INSUFFICIENT TO FILL CHAMBER B. THE PRESSURE IN THE RESERVE TUBE IS NOW GREATER THAN THAT IN CHAMBER B, FORCING THE COMPRESSION INTAKE VALVE TO UNSEAT. FLUID THEN FLOWS FROM THE RESERVE TUBE INTO CHAMBER B, KEEPING THE PRESSURE TUBE FULL.

EXTENSION CONTROL IS A FORCE PRESENT AS A RESULT OF THE HIGHER PRESSURE IN CHAMBER A, ACTING ON THE TOPSIDE OF THE PISTON AREA.

DIFFERENT SHOCK ABSORBER DESIGN

THERE ARE SEVERAL SHOCK ABSORBER DESIGNS IN USE TODAY:
  • TWIN TUBE DESIGNS
  1. GAS CHARGED
  2. ASD
  3. PSD
  • MONO TUBE DESIGN

BASIC TWIN TUBE DESIGN
THE TWIN TUBE DESIGN HAS AN INNER TUBE KNOWN AS THE WORKING OR PRESSURE TUBE AND AN OUTER TUBE KNOWN AS THE RESERVE TUBE. THE OUTER TUBE IS USED TO STORE EXCESS HYDRAULIC FLUID.

THERE ARE MANY TYPES OF SHOCK ABSORBER MOUNTS USED TODAY. MOST OF THESE USE RUBBER BUSHINGS BETWEEN THE SHOCK ABSORBER AND THE FRAME OR SUSPENSION TO REDUCE TRANSMITTED ROAD NOISE AND SUSPENSION VIBRATION. THE RUBBER BUSHINGS ARE FLEXIBLE TO ALLOW MOVEMENT DURING SUSPENSION TRAVEL. THE UPPER MOUNT OF THE SHOCK ABSORBER CONNECTS TO THE VEHICLE FRAME.





NOTICE THAT THE PISTON ROD PASSES THROUGH A ROD GUIDE AND A SEAL AT THE UPPER END OF THE PRESSURE TUBE. THE ROD GUIDE KEEPS THE ROD IN LINE WITH THE PRESSURE TUBE AND ALLOWS THE PISTON TO MOVE FREELY INSIDE. THE SEAL KEEPS THE HYDRAULIC OIL INSIDE AND CONTAMINATION OUT.

THE BASE VALVE LOCATED AT THE BOTTOM OF THE PRESSURE TUBE IS CALLED A COMPRESSION VALVE. IT CONTROLS FLUID MOVEMENT DURING THE COMPRESSION CYCLE.


BORE SIZE IS THE DIAMETER OF THE PISTON AND THE INSIDE OF THE PRESSURE TUBE. GENERALLY, THE LARGER THE UNIT, THE HIGHER THE POTENTIAL CONTROL LEVELS BECAUSE OF THE LARGER PISTON DISPLACEMENT AND PRESSURE AREAS. THE LARGER THE PISTON AREA, THE LOWER THE INTERNAL OPERATING PRESSURE AND TEMPERATURES. THIS PROVIDES HIGHER DAMPING CAPABILITIES.

RIDE ENGINEERS SELECT VALVING VALUES FOR A PARTICULAR VEHICLE TO ACHIEVE OPTIMAL RIDE CHARACTERISTICS OF BALANCE AND STABILITY UNDER A WIDE VARIETY OF DRIVING CONDITIONS. THEIR SELECTION OF VALVE SPRINGS AND ORIFICES CONTROL FLUID FLOW WITHIN THE UNIT, WHICH DETERMINES THE FEEL AND HANDLING OF THE VEHICLE.


TWIN TUBE – GAS CHARGED DESIGN
THE DEVELOPMENT OF GAS CHARGED SHOCK ABSORBERS WAS A MAJOR ADVANCE IN RIDE CONTROL TECHNOLOGY. THIS ADVANCE SOLVED MANY RIDE CONTROL PROBLEMS WHICH OCCURRED DUE TO AN INCREASING NUMBER OF VEHICLES USING UNI-BODY CONSTRUCTION, SHORTER WHEELBASES AND INCREASED USE OF HIGHER TIRE PRESSURES.



THE DESIGN OF TWIN TUBE GAS CHARGED SHOCK ABSORBERS SOLVES MANY OF TODAY’S RIDE CONTROL PROBLEMS BY ADDING A LOW PRESSURE CHARGE OF NITROGEN GAS IN THE RESERVE TUBE. THE PRESSURE OF THE NITROGEN IN THE RESERVE TUBE VARIES FROM 100 TO 150 PSI, DEPENDING ON THE AMOUNT OF FLUID IN THE RESERVE TUBE. THE GAS SERVES SEVERAL IMPORTANT FUNCTIONS TO IMPROVE THE RIDE CONTROL CHARACTERISTICS OF A SHOCK.

THE PRIME FUNCTION OF GAS CHARGING IS TO MINIMIZE AERATION OF THE HYDRAULIC FLUID. THE PRESSURE OF THE NITROGEN GAS COMPRESSES AIR BUBBLES IN THE HYDRAULIC FLUID. THIS PREVENTS THE OIL AND AIR FROM MIXING AND CREATING FOAM. FOAM AFFECTS PERFORMANCE BECAUSE IT CAN BE COMPRESSED – FLUID CAN NOT. WITH AERATION REDUCED, THE SHOCK IS ABLE TO REACT FASTER AND MORE PREDICTABLY, ALLOWING FOR QUICKER RESPONSE TIME AND HELPING KEEP THE TIRE FIRMLY PLANTED ON THE ROAD SURFACE.
AN ADDITIONAL BENEFIT OF GAS CHARGING IS THAT IT CREATES A MILD BOOST IN SPRING RATE TO THE VEHICLE. THIS DOES NOT MEAN THAT A GAS CHARGED SHOCK WOULD RAISE THE VEHICLE UP TO CORRECT RIDE HEIGHT IF THE SPRINGS WERE SAGGING. IT DOES HELP REDUCE BODY ROLL, SWAY, BRAKE DIVE, AND ACCELERATION SQUAT.

THIS MILD BOOST IN SPRING RATE IS ALSO CAUSED BY THE DIFFERENCE IN THE SURFACE AREA ABOVE AND BELOW THE PISTON. WITH GREATER SURFACE AREA BELOW THE PISTON THAN ABOVE, MORE PRESSURIZED FLUID IS IN CONTACT WITH THIS SURFACE. THIS IS WHY A GAS CHARGED SHOCK ABSORBER WILL EXTEND ON ITS OWN.

THE FINAL IMPORTANT FUNCTION OF THE GAS CHARGE IS TO ALLOW ENGINEERS GREATER FLEXIBILITY IN VALVING DESIGN. IN THE PAST SUCH FACTORS AS DAMPING AND AERATION FORCED COMPROMISES IN DESIGN.



ADVANTAGES:
IMPROVES HANDLING BY REDUCING ROLL, SWAY AND DIVE .
REDUCES AERATION OFFERING A GREATER RANGE OF CONTROL OVER A WIDER VARIETY OF ROAD CONDITIONS AS COMPARED TO NON-GAS UNITS.
REDUCED FADE – SHOCKS CAN LOSE DAMPING CAPABILITY AS THEY HEAT UP DURING USE. GAS CHARGED SHOCKS COULD CUT THIS LOSS OF PERFORMANCE, CALLED FADE.

DISADVANTAGES:
CAN ONLY BE MOUNTED IN ONE DIRECTION.

CURRENT USES:
ORIGINAL EQUIPMENT ON MANY DOMESTIC PASSENGER CAR, SUV AND LIGHT TRUCK APPLICATIONS.
TWIN TUBE – PSD DESIGN

IN OUR EARLIER DISCUSSION OF HYDRAULIC SHOCK ABSORBERS WE DISCUSSED THAT IN THE PAST, RIDE ENGINEERS HAD TO COMPROMISE BETWEEN SOFT VALVING AND FIRM VALVING. WITH SOFT VALVING, THE FLUID FLOWS MORE EASILY. THE RESULT IS A SMOOTHER RIDE, BUT WITH POOR HANDLING AND A LOT OF ROLL/SWAY. WHEN VALVING IS FIRM, FLUID FLOWS LESS EASILY. HANDLING IS IMPROVED, BUT THE RIDE CAN BECOME HARSH.

WITH THE ADVENT OF GAS CHARGING, RIDE ENGINEERS WERE ABLE TO OPEN UP THE ORIFICE CONTROLS OF THESE VALVES AND IMPROVE THE BALANCE BETWEEN COMFORT AND CONTROL CAPABILITIES AVAILABLE IN TRADITIONAL VELOCITY SENSITIVE DAMPERS.

A LEAP BEYOND FLUID VELOCITY CONTROL IS AN ADVANCED TECHNOLOGY THAT TAKES INTO ACCOUNT THE POSITION OF THE VALVE WITHIN THE PRESSURE TUBE. THIS IS CALLED POSITION SENSITIVE DAMPING (PSD).


THE KEY TO THIS INNOVATION IS PRECISION TAPERED GROOVES IN THE PRESSURE TUBE. EVERY APPLICATION IS INDIVIDUALLY TUNED, TAILORING THE LENGTH, DEPTH, AND TAPER OF THESE GROOVES TO ENSURE OPTIMAL RIDE COMFORT AND ADDED CONTROL. THIS IN ESSENCE CREATES TWO ZONES WITHIN THE PRESSURE TUBE.
THE FIRST ZONE, THE COMFORT ZONE, IS WHERE NORMAL DRIVING TAKES PLACE. IN THIS ZONE THE PISTON TRAVEL REMAINS WITHIN THE LIMITS OF THE PRESSURE TUBE’S MID RANGE. THE TAPERED GROOVES ALLOW HYDRAULIC FLUID TO PASS FREELY AROUND AND THROUGH THE PISTON DURING ITS MIDRANGE TRAVEL. THIS ACTION REDUCES RESISTANCE ON THE PISTON, ASSURING A SMOOTH, COMFORTABLE RIDE.

THE SECOND ZONE, THE CONTROL ZONE, IS UTILIZED DURING DEMANDING DRIVING SITUATIONS. IN THIS ZONE THE PISTON TRAVELS OUT OF THE MID RANGE AREA OF THE PRESSURE TUBE AND BEYOND THE GROOVES. THE ENTIRE FLUID FLOW IS DIRECTED THROUGH THE PISTON VALVING FOR MORE CONTROL OF THE VEHICLE’S SUSPENSION. THE RESULT IS IMPROVED VEHICLE HANDLING AND BETTER CONTROL WITHOUT SACRIFICING RIDE COMFORT.

ADVANTAGES:
  • ALLOWS RIDE ENGINEERS TO MOVE BEYOND SIMPLE VELOCITY SENSITIVE VALVING AND USE THE POSITION OF THE PISTON TO FINE TUNE THE RIDE CHARACTERISTIC.
  • ADJUSTS MORE RAPIDLY TO CHANGING ROAD AND WEIGHT CONDITIONS THAN STANDARD SHOCK ABSORBERS
  • TWO SHOCKS INTO ONE – COMFORT AND CONTROL
DISADVANTAGES:
IF VEHICLE RIDE HEIGHT IS NOT WITHIN MANUFACTURER’S SPECIFIED RANGE, PISTON TRAVEL MAY BE LIMITED TO THE CONTROL ZONE.

CURRENT USES:
PRIMARILY AFTERMARKET UNDER THE SENSA-TRAC BRAND NAME.


TWIN TUBE –ASD DESIGN

WE HAVE DISCUSSED THE COMPROMISES MADE BY RIDE ENGINEERS TO BRING COMFORT AND CONTROL TOGETHER INTO ONE SHOCK ABSORBER. THIS COMPROMISE HAS BEEN SIGNIFICANTLY REDUCED BY THE ADVENT OF GAS CHARGING AND POSITION SENSITIVE DAMPING TECHNOLOGY.

A NEW TWIST ON THE COMFORT/ CONTROL COMPROMISE IS AN INNOVATIVE TECHNOLOGY WHICH PROVIDES GREATER CONTROL FOR HANDLING WHILE IMPROVING RIDE COMFORT CALLED ACCELERATION SENSITIVE DAMPING (ASD).

THIS TECHNOLOGY MOVES BEYOND TRADITIONAL VELOCITY SENSITIVE DAMPING TO FOCUS AND ADDRESS IMPACT. THIS FOCUS ON IMPACT IS ACHIEVED BY UTILIZING A NEW COMPRESSION VALVE DESIGN. THIS COMPRESSION VALVE IS A MECHANICAL CLOSED LOOP SYSTEM, WHICH OPENS A BYPASS TO FLUID FLOW AROUND THE COMPRESSION VALVE.




THIS NEW APPLICATION SPECIFIC DESIGN ALLOWS MINUTE CHANGES INSIDE THE PRESSURE TUBE BASED ON INPUTS RECEIVED FROM THE ROAD. THE COMPRESSION VALVE WILL SENSE A BUMP IN THE ROAD AND AUTOMATICALLY ADJUST THE SHOCK TO ABSORB THE IMPACT, LEAVING THE SHOCK WITH GREATER CONTROL WHEN IT IS NEEDED.

ADVANTAGES:
CONTROL IS ENHANCED WITHOUT SACRIFICING DRIVER COMFORT.
VALVE AUTOMATICALLY ADJUSTS TO CHANGES IN THE ROAD CONDITION.
REDUCES RIDE HARSHNESS.

DISADVANTAGES:
LIMITED AVAILABILITY

CURRENT USES:
PRIMARILY AFTERMARKET APPLICATIONS UNDER THE REFLEX BRAND NAME.
MONO-TUBE DESIGN

THESE ARE HIGH-PRESSURE GAS SHOCKS WITH ONLY ONE TUBE, THE PRESSURE TUBE. INSIDE THE PRESSURE TUBE THERE ARE TWO PISTONS: A DIVIDING PISTON AND A WORKING PISTON. THE WORKING PISTON AND ROD ARE VERY SIMILAR TO THE TWIN TUBE SHOCK DESIGN. THE DIFFERENCE IN ACTUAL APPLICATION IS THAT A MONO-TUBE SHOCK ABSORBER CAN BE MOUNTED UPSIDE DOWN OR RIGHT SIDE UP AND WILL WORK EITHER WAY. IN ADDITION TO ITS MOUNTING FLEXIBILITY, MONO-TUBE SHOCKS ARE A SIGNIFICANT COMPONENT, ALONG WITH THE SPRING, IN SUPPORTING VEHICLE WEIGHT.
ANOTHER DIFFERENCE YOU MAY NOTICE IS THAT THE MONO-TUBE SHOCK ABSORBER DOES NOT HAVE A BASE VALVE. INSTEAD, ALL OF THE CONTROL DURING COMPRESSION AND EXTENSION TAKES PLACE AT THE PISTON.


THE PRESSURE TUBE OF THE MONO-TUBE DESIGN IS LARGER THAN A TWIN TUBE DESIGN TO ACCOMMODATE FOR DEAD LENGTH. THIS HOWEVER MAKES IT DIFFICULT TO APPLY THIS DESIGN TO PASSENGER CARS DESIGNED OE WITH A TWIN TUBE DESIGN. A FREE-FLOATING DIVIDING PISTON TRAVELS IN THE LOWER END OF THE PRESSURE TUBE, SEPARATING THE GAS CHARGE AND THE OIL.

THE AREA BELOW THE DIVIDING PISTON IS PRESSURIZED TO ABOUT 360 PSI WITH NITROGEN GAS. THIS HIGH GAS PRESSURE HELPS SUPPORT SOME OF THE VEHICLE’S WEIGHT. THE OIL IS LOCATED IN THE AREA ABOVE THE DIVIDING PISTON.

DURING OPERATION, THE DIVIDING PISTON MOVES UP AND DOWN AS THE PISTON ROD MOVES IN AND OUT OF THE SHOCK ABSORBER, KEEPING THE PRESSURE TUBE FULL ALL TIMES.

ADVANTAGES:
  • CAN BE MOUNTED UPSIDE DOWN, REDUCING THE UNSPRUNG WEIGHT
  • MAY RUN COOLER SINCE THE WORKING TUBE IS EXPOSED TO THE AIR
DISADVANTAGES:
  • DIFFICULT TO APPLY TO PASSENGER CARS DESIGNED OE WITH TWIN TUBE DESIGNS.
  • A DENT IN THE PRESSURE TUBE WILL DESTROY THE UNIT
CURRENT USES:
  • ORIGINAL EQUIPMENT MANY IMPORT AND PERFORMANCE DOMESTIC PASSENGER CARS, SUV AND LIGHT TRUCK APPLICATIONS
  • AVAILABLE FOR MANY AFTERMARKET APPLICATIONS


THE MAGNETIC SHOCK ABSORBER
SHOCK ABSORBERS ARE A KEY COMPONENT OF ALL AUTOMOBILES. THEY CONTROL THE VEHICLE’S SUSPENSION MOVEMENT TO PROVIDE A STABLE, COMFORTABLE RIDE. SINCE THEY WERE INSTALLED ON THE FIRST AUTOMOBILES, THE PRINCIPLE OF SHOCK ABSORBER OPERATION HAS REMAINED ESSENTIALLY THE SAME. NOW A NEW TYPE OF SHOCK ABSORBER IS ENTERING THE MARKET, AND IT MAY CHANGE THE WAY SUSPENSIONS ARE CONTROLLED. THEY ARE CALLED THE MAGNETIC SHOCK ABSORBERS OR THE NEW MAGNERIDE SHOCK SYSTEM.
MAGNETIC SHOCK ABSORBER IS A CONTINUOUSLY VARIABLE SHOCK ABSORBER THAT USES SIMPLE MAGNETIC PRINCIPLES BUT VERY HIGH TECHNOLOGY TO CONTROL SUSPENSIONS.
CONVENTIONAL SHOCK ABSORBERS (OR STRUTS ON MANY CARS) USE OIL PASSING THROUGH ORIFICES TO DAMPEN SUSPENSION MOVEMENT. WHEN A TIRE HITS A BUMP, THE SUSPENSION MOVES UP, MOVING THE BODY OF THE SHOCK ABSORBER UP TOO. A ROD, CONNECTED TO THE TOP OF THE SHOCK AND MOUNTED TO THE BODY OR FRAME, PASSES THROUGH A SEAL IN THE TOP OF THE SHOCK AND HAS A PISTON MOUNTED ON THE BOTTOM END. THIS PISTON HAS SMALL PORTS IN IT THAT ALLOW OIL CONTAINED IN THE SHOCK BODY TO FLOW FROM ONE SIDE OF THE PISTON TO THE OTHER. DIFFERENT SIZE PORTS ALLOW DIFFERENT FLOW RATES, SO LARGER PORTS ALLOW THE SUSPENSION TO MOVE EASIER AND SMALLER PORTS SLOW THE MOVEMENT.
CONVENTIONAL SHOCK ABSORBERS USE CHECK VALVES ON THE PORTS SO THAT FLUID CAN PASS EASIER ONE WAY THAN THE OTHER. TYPICALLY, THE WHEEL IS ALLOWED TO MOVE UP QUICKLY, BUT LET BACK DOWN SLOWER. THIS PREVENTS THE SUSPENSION FROM BOUNCING; THE EFFECT YOU GET WHEN THE SHOCKS ARE BADLY WORN.
GAS-FILLED SHOCKS USE PRESSURE INSIDE THE SHOCK TO REDUCE OIL FOAMING AS IT PASSES THROUGH THE PORTS. SUSPENSION CONTROL BECOMES VERY ERRATIC WITH FOAMY OIL INSIDE THE SHOCK. VEHICLES WITH SELECTABLE SHOCK DAMPENING VARY THE SIZE OF PORTS BY TURNING A SHAFT INSIDE THE PISTON ROD THAT CHANGES PORT SIZE TO CHANGE VEHICLE HANDLING. MAGNETIC SHOCK ABSORBER MAKES MECHANICALLY VARIED SYSTEMS OBSOLETE.

THE HEART OF A MAGNETIC SHOCK ABSORBER OR MAGNERIDE IS THE MAGNETO-RHEOLOGICAL (MR) FLUID. IT IS A SUSPENSION OF MAGNETICALLY SOFT PARTICLES SUCH AS IRON MICROSPHERES IN A SYNTHETIC HYDROCARBON BASE FLUID. PLACE A MAGNET NEAR THE FLUID AND THE PARTICLES FORM A FIBROUS STRUCTURE, INCREASING ITS SHEAR FACTOR. IN SIMPLE TERMS, THE FLUID GETS THICKER SO IT DOESN’T FLOW THROUGH THE SHOCK’S PISTON PORTS AS EASY.
BY USING AN MAGNET PLACED IN THE SHOCK PISTON, THE MR FLUID ONLY CHANGES VISCOSITY WHERE IT PASSES THROUGH THE PORTS. WIRES RUN DOWN THE HOLLOW PISTON ROD SO A COMPUTER MODULE CAN VARY THE STRENGTH OF THE MAGNET AND THE DAMPENING OF THE SHOCK CONTINUOUSLY. THE SYSTEM IS FIVE TIMES FASTER THAN MECHANICAL RIDE CONTROL SYSTEMS.
IN FACT, THE SYSTEM IS SO QUICK, IT PERFORMS 1000 CALCULATIONS PER SECOND. THIS IS EQUAL TO ONE CALCULATION FOR EVERY INCH OF VEHICLE TRAVEL AT 60 MILES PER HOUR. ELECTRO-MAGNETIC SHOCK ABSORBERS CAN REACT TO EVERY LITTLE BUMP IN THE ROAD.
SEVERAL SENSORS PROVIDE INPUT TO THE MAGNERIDE COMPUTER. WHEEL TO BODY SENSORS ARE USED AT EACH WHEEL TO DETERMINE WHEEL TRAVEL AND VERTICAL ACCELERATION. VEHICLE SPEED AND OUTSIDE TEMPERATURE COME VIA DATA COMMUNICATION FROM OTHER VEHICLE COMPUTERS. THE TEMPERATURE DATA IS USED SO THE COMPUTER CAN COMPENSATE FOR FLUID VISCOSITY VARIATIONS DUE TO TEMPERATURE. MAGNERIDE ALSO IMPROVES VEHICLE STABILITY CONTROL SYSTEMS AND USES A STEERING WHEEL ANGLE SENSOR, YAW RATE SENSOR AND LATERAL ACCELERATION SENSOR FOR ACCURATE VEHICLE CONTROL.
FOR THE AUTO ENGINEERS, MAGNERIDE ALLOWS QUICKER CALIBRATION AND SUSPENSION TUNING FOR NEW VEHICLES. FOR DRIVERS, MAGNERIDE OFFERS A FLATTER, SMOOTHER RIDE, ENHANCED LATERAL AND LONGITUDINAL CONTROL OF BODY MOVEMENT, AND BETTER ROAD ISOLATION FROM THE PASSENGER COMPARTMENT. WHILE MAGNERIDE HAS LIMITED AVAILABILITY NOW, I PREDICT WE WILL SEE THIS FEATURE ON A WIDE RANGE OF AUTOMOBILES IN THE NEAR FUTURE.


THE NEW WAVE IN SHOCK ABSORBERS
OVER THE PAST TWO MODEL YEARS, GENERAL MOTORS (GM) HAS INTRODUCED ONE OF THE MOST INTERESTING AND POTENTIALLY FAR-REACHING NEW TECHNOLOGIES EVER DEVELOPED FOR AUTOMOBILES. THE CHEVROLET CORVETTE AND THE CADILLAC SRX, STS AND XLR MODELS ARE ALL AVAILABLE WITH MAGNETIC RIDE CONTROL. CALLED MAGNERIDE BY ITS SUPPLIER DELPHI AUTOMOTIVE SYSTEMS, IT USES A COMPUTER TO ADJUST THE SHOCK ABSORBERS’ DAMPING RATE. WHILE ELECTRONIC DAMPING ADJUSTMENT IS NOTHING NEW, THE SHOCK ABSORBERS THEMSELVES ARE DIFFERENT FROM ANYTHING YOU’VE SEEN BEFORE. INSTEAD OF ADJUSTABLE VALVES, THESE SHOCKS HAVE ADJUSTABLE OIL.
A HYDRAULIC SHOCK ABSORBER DAMPENS SUSPENSION MOVEMENT BY FORCING A PISTON TO MOVE THROUGH OIL. HOLES IN THE PISTON ARE COVERED BY SPRING-LOADED VALVES. THESE VALVES SLOW THE FLOW OF OIL THROUGH THE HOLES TO CONTROL DAMPING RATE: THE SMALLER THE VALVE OPENING, THE SLOWER THE OIL FLOW AND THE GREATER THE DAMPING. ADJUSTABLE SHOCK ABSORBERS VARY THE SHOCK’S DAMPING RATE BY VARYING THE SIZE OF THE VALVE OPENING, EITHER BY ADJUSTING THE SPRING PRELOAD OR BY SELECTING A DIFFERENT SIZE OIL FLOW ORIFICE. BY USING A SMALL MOTOR OR A SOLENOID TO OPERATE THE VALVE, DAMPING RATE CAN BE ADJUSTED “ON-THE-FLY” BY THE DRIVER AND/OR BY THE COMPUTER.
EXACTLY THE SAME RESULTS CAN BE ACHIEVED BY VARYING THE VISCOSITY OF THE OIL INSTEAD OF THE SIZE OF THE VALVE OPENING. THE TECHNOLOGY THAT ALLOWS CHANGING OIL VISCOSITY ON-THE-FLY PRESENTS SOME EXCITING POSSIBILITIES THAT GO FAR BEYOND ADJUSTABLE SHOCK ABSORBERS.

MAGNETO-RHEOLOGICAL FLUID

RHEOLOGY IS A SCIENCE THAT STUDIES THE DEFORMATION AND FLOW OF MATERIALS. RHEOLOGICAL FLUIDS HAVE FLOW CHARACTERISTICS THAT CAN BE CHANGED IN A CONTROLLABLE WAY USING ELECTRICAL CURRENT OR A MAGNETIC FIELD. DEPENDING ON THE BASE FLUID AND THE STRENGTH OF THE ELECTRICAL CURRENT OR MAGNET, THE FLUID’S VISCOSITY CAN BE VARIED FROM THINNER-THAN-WATER TO ALMOST-SOLID AND ANY STAGE IN BETWEEN. THE FLUID’S RESPONSE IS INSTANTANEOUS, COMPLETELY REVERSIBLE AND EXTREMELY CONTROLLABLE, BUT THERE ARE SOME LIMITS.
ELECTRO-RHEOLOGICAL (ER) FLUID CHANGES VISCOSITY WHEN AN ELECTRIC CURRENT IS APPLIED DIRECTLY TO THE FLUID ITSELF. ER FLUID WAS FIRST INVENTED AND PATENTED IN THE 1940S, AND TO VARYING DEGREES, DEVELOPMENT HAS CONTINUED EVER SINCE. IT HAS BEEN TESTED IN A WIDE RANGE OF APPLICATIONS, FROM TORQUE CONVERTERS, CLUTCHES AND DAMPERS TO SYNTHETIC MUSCLES AND DAMPERS IN POWERED PROSTHETIC ARMS AND LEGS. IT WORKS, BUT ITS SHEAR STRENGTH – THAT IS, ITS RESISTANCE TO SHEARING MOVEMENT – IS LIMITED. DESPITE HUGE INVESTMENTS IN RESEARCH AND DEVELOPMENT, ER FLUID IS STILL FAR FROM READY FOR ANY PRACTICAL APPLICATIONS.
MAGNETO-RHEOLOGICAL (MR) FLUID HAS A SHEAR STRENGTH ABOUT 10 TIMES STRONGER THAN ER FLUID. INVENTED AT THE SAME TIME AS ER FLUID, THE TWO HAVE MANY SIMILARITIES. BOTH CAN USE OIL, SILICONE, WATER OR GLYCOL AS THE BASE FLUID, AND BOTH CONTAIN POLARIZABLE PARTICLES SUSPENDED IN THE FLUID. POLARIZABLE MEANS THE PARTICLES CAN BE FORCED TO ALIGN IN A SPECIFIC WAY. THESE SUSPENDED POLARIZABLE PARTICLES ARE THE BASIC DIFFERENCE BETWEEN ER AND MR FLUIDS. ER FLUID USES PARTICLES THAT POLARIZE WHEN DIRECTLY EXPOSED TO AN ELECTRIC CURRENT. MR FLUID USES SOMEWHAT LARGER PARTICLES OF IRON THAT POLARIZE WHEN SURROUNDED BY A MAGNETIC FIELD.
THE TYPICAL MR FLUID PARTICLES ARE SOFT IRON SPHERES MEASURING 3 TO 5 MICRONS (3 TO 5 THOUSANDTHS OF A MILLIMETER) IN DIAMETER. DEPENDING ON THE APPLICATION, THE FLUID WILL BE 20 TO 40 PERCENT SATURATED WITH THE IRON PARTICLES, AND OTHER ADDITIVES WILL BE USED TO CONTROL PARTICLE SETTLING AND MIXING, FLUID FRICTION AND FLUID VISCOSITY. SPECIFIC GRAVITY IS GENERALLY BETWEEN 3 AND 4; FOR REFERENCE, WATER’S SPECIFIC GRAVITY IS 1. THUS, A 55-GALLON DRUM OF MR FLUID CAN WEIGH ALMOST A FULL TON. MR FLUIDS ARE DEVELOPED SPECIFICALLY FOR THE APPLICATION. FOR INSTANCE, IN ADDITION TO AUTOMOTIVE USES, MR FLUIDS HAVE BEEN DEVELOPED FOR USE IN DAMPERS THAT PROTECT BUILDINGS AND OTHER STRUCTURES FROM EARTHQUAKE DAMAGE. THESE DAMPERS SIT STILL FOR LONG PERIODS, SO DIFFERENT ADDITIVES ARE NEEDED TO KEEP THE PARTICLES IN SUSPENSION.
SHOCK ABSORBER VALVES

IT WASN’T HARD TO DEVELOP A SYNTHETIC OIL-MR FLUID WITH VISCOSITY AND LUBRICATION QUALITIES SIMILAR TO NORMAL HYDRAULIC SHOCK ABSORBER OIL. THE CHALLENGE WAS TO DEVELOP SEALS, O-RINGS AND OTHER COMPONENTS THAT CAN WITHSTAND THE FLUID’S “PARTICLE CONTAMINATION,” WHICH IS PART OF THE REASON IT’S TAKEN SO LONG FOR MR FLUID TO ESCAPE THE LABORATORY. ACCORDING TO DAVID CALDWELL, COMMUNICATIONS MANAGER FOR PERFORMANCE CARS AT GM, THESE SHOCKS HAVE BEEN IN DEVELOPMENT FOR 20 YEARS. HE SAID THEY WERE FIRST USED ON OPEN-WHEELED RACECARS, WHERE COST AND DURABILITY ARE NOT QUITE AS CRITICAL AS IN PRODUCTION CARS. WORKING WITH LORD CORP., WHICH MANUFACTURES THE MR FLUID, DELPHI HAS FINALLY DEVELOPED MR SHOCK ABSORBERS THAT ARE SUITABLE FOR REAL-WORLD APPLICATIONS.
THE ‘VALVE’ IN THE CENTER OF THE TUBE IS A BLOCK WITH OIL PASSAGES SURROUNDED BY AN ELECTROMAGNET COIL.


THE MAGNETIC PARTICLES IN THE FLUID ALIGN WITH THE MAGNETIC FIELD WHEN THE MAGNET IS TURNED ON. THE FLUID RESISTS FLOW PERPENDICULAR TO THE FIELD LINES JUST AS IF AN ORIFICE PLUG WERE SUDDENLY INSERTED INTO THE PASSAGE.

WITH THE FLUID AND OTHER MATERIALS PROPERLY MATCHED, DEVELOPING THE VALVE ITSELF WAS THE SIMPLEST PART OF THE SYSTEM. THERE ARE NO MOVING PARTS, JUST PASSAGES IN THE PISTON THAT THE FLUID MOVES THROUGH. THE OIL PASSAGES ARE SURROUNDED BY AN ELECTRO-MAGNET; IT IS BASICALLY A SOLENOID COIL WITHOUT THE VALVE CORE THAT GENERATES A MAGNETIC FIELD WHEN CURRENT IS PASSED THROUGH IT. WHEN THE MAGNET IS TURNED ON, THE IRON PARTICLES IN THE OIL PASSAGES ALIGN TO FORM FIBERS IN THE OIL, MAKING THE FLUID THICKER AND, THEREFORE, RESISTANT TO FLOW. THE THICKNESS OR VISCOSITY OF THE FLUID CAN BE INFINITELY ADJUSTED FROM THAT OF THE BASE OIL TO ALMOST PLASTIC IN LESS THAN TWO MILLISECONDS SIMPLY BY ADJUSTING CURRENT FLOW THROUGH THE COIL. WHEN THE CURRENT IS TURNED OFF, THE FLUID REVERTS TO ITS BASE VISCOSITY JUST AS QUICKLY. ONLY THE FLUID IN THE OIL PASSAGE IS INVOLVED, SO THE MAGNET’S COIL CAN BE SMALL ENOUGH TO RIDE ON THE PISTON ITSELF. THE WIRES FROM THE COIL ARE ROUTED THROUGH THE PISTON ROD TO A CONNECTOR ON THE END OF THE SHOCK HOUSING. THIS BASIC DESIGN IS CURRENTLY BEING USED IN LONG-HAUL TRUCK SEATS, SHOCKS, STRUTS AND AIR-INFLATED LOAD-LEVELING SHOCKS.


CONTROL SYSTEM

BECAUSE ADJUSTABLE DAMPING HAS BEEN AROUND FOR A WHILE, ALL OF THE OTHER BITS AND PIECES NEEDED FOR THE MAGNERIDE SYSTEM ARE ALREADY IN PLACE. THE CONTROL MODULE USES SUSPENSION HEIGHT DATA SUPPLIED BY POSITION SENSORS AT EACH CORNER. WITH THROTTLE POSITION SENSOR (TPS), TRANSMISSION AND WHEEL SPEED DATA SUPPLIED BY THE POWERTRAIN CONTROL MODULE (PCM), THE SUSPENSION CONTROLLER CAN PREDICT LIFT AND DIVE AT EACH END OF THE CAR AND OPERATE THE SHOCKS’ “VALVES” TO COUNTERACT IT. WITH DATA FROM A STEERING WHEEL POSITION SENSOR, A TWO-PLANE ACCELERATION SENSOR AND A YAW RATE SENSOR, THE SHOCKS CAN BE OPERATED AS NEEDED TO CONTROL BODY ROLL DURING ANY MANEUVER. THE SYSTEM ALSO CHECKS BODY MOVEMENT DURING ANTILOCK BRAKE SYSTEM (ABS) OPERATION USING VEHICLE SPEED, WHEEL SPEED AND OTHER DATA SUPPLIED BY THE ABS CONTROL UNIT.
THE MAGNERIDE CONTROLLER ITSELF IS A STAND-ALONE UNIT EQUIPPED WITH TWO PARALLEL PROCESSORS: ONE FOR INPUT SIGNALS AND ONE FOR OUTPUT. IT OPERATES THE SHOCKS ON 5 VOLTS DC THAT IS PULSE-WIDTH MODULATED TO ADJUST CURRENT TO THE MAGNETS. CURRENT DRAW CAN SPIKE MOMENTARILY AT ABOUT 5 AMPS PER SHOCK, BUT NORMAL CURRENT DRAW IS ABOUT HALF THAT MUCH, AND THERE IS ALWAYS SOME CURRENT FLOWING WHENEVER THE KEY IS ON.
LIKE EARLIER VERSIONS, THIS IS A SEMI-ACTIVE SUSPENSION SYSTEM. IN ADDITION TO ITS MAIN FUNCTION OF KEEPING THE WHEELS IN CONTACT WITH THE ROAD, IT CAN CHECK BODY MOTIONS AND, WITHIN CERTAIN LIMITS, ADJUST WEIGHT BIAS AT EACH CORNER BY PREVENTING SUSPENSION COMPRESSION. BUT IT IS A REACTIVE SYSTEM, NOT PROACTIVE, AND IT CANNOT EXTEND THE SUSPENSION TO MAKE THE CAR LEAN INTO A TURN. STILL, IT PROVIDES A SIGNIFICANT AMOUNT OF INCREASED CONTROL WITH BASE SETTINGS THAT ARE TUNED FOR A MORE COMFORTABLE RIDE.


A PERMANENT MAGNET SYSTEM SHOCK ABSORBER
A PERMANENT MAGNETIC SUSPENSION APPARATUS FOR MAINTAINING A SPACED RELATIONSHIP BETWEEN A FIRST MOVABLE MEMBER AND A SECOND FIXED MEMBER, WHEREIN THE MOTION OF THE MOVABLE MEMBER REQUIRES DAMPENING, CUSHIONING, STABILIZING, HARMONIC BALANCING, AND/ OR REFLEXIVE RE-CENTERING.
THE SUSPENSION APPARATUS INCLUDES A PLURALITY OF SETS OF PERMANENT MAGNETS LOCATED WITHIN A CASE, WHICH IS COUPLED TO ONE OF THE MEMBERS. THE SETS OF PERMANENT MAGNETS ARE COUPLED TO AN ELONGATED SUPPORT MEMBER, WHICH IS COUPLE TO THE SECOND MEMBER. THE SUPPORT MEMBER EXTENDS WITHIN THE CASE, WITH THE SUPPORT MEMBER AND THE CASE BEING ADAPTED FOR RELATIVE AXIAL MOVEMENT.










THE SETS OF PERMANENT MAGNETS ARE ARRANGED IN BIDIRECTIONAL REPULSION CONFIGURATION WITH ADDITIONAL MAGNET FIXED WITHIN THE CASE. THE SETS OF PERMANENT MAGNETS ARE BEING MOVED RELATIVE TO THE FIXED PERMANENT MAGNETS, SUCH THAT THE MAGNETIC FORCES OF REPULSION PRODUCED BY THE PERMANENT MAGNETS ARE INCREASED IN RESPONSE TO RELATIVE MOVEMENT BETWEEN THE SUPPORT MEMBER AND THE CASE, CREATING DAMPENING, CUSHIONING, STABILIZING, HARMONIC BALANCING, AND/OR RE-CENTERING FORCES.
IN ONE EMBODIMENT, THE CONTROL MECHANISM IS COUPLED BETWEEN THE FRAME OF A VEHICLE AND A WHEEL SUPPORT ASSEMBLY. THE PERMANENT MAGNETIC SUSPENSION APPARATUS, HOWEVER, IS FOR USE WITH ANY TYPE OF EQUIPMENT OR MACHINERY HAVING A MOVABLE AND NON-MOVABLE, OR FIXED, MEMBER. THIS INCLUDES, BUT IS NOT LIMITED TO, CARS, TRUCKS, MOTORCYCLES, SCOOTERS, ALL TERRAIN VEHICLES, SEMI-TRACTORS, SEMI-TRAILERS, AND THE LIKE, AS WELL AS, BUT NOT LIMITED TO, INDUSTRIAL EQUIPMENT AND MACHINERY, HOSPITAL AND OFFICE MACHINERY AND EQUIPMENT, SUCH AS BEING COUPLED BETWEEN THE FRAME OF AN OFFICE CHAIR AND THE CHAIR SEAT.




REGENERATIVE ELECTROMAGNETIC SHOCK ABSORBER
A REGENERATIVE ELECTROMAGNETIC SHOCK ABSORBER COMPRISING: A LINEAR ELECTROMAGNETIC GENERATOR COMPRISED OF A CENTRAL MAGNET ARRAY ASSEMBLY COMPRISING A CENTRAL MAGNET ARRAY COMPRISED OF A PLURALITY OF AXIALLY-ALIGNED, STACKED CYLINDRICAL MAGNETS HAVING LIKE MAGNETIC POLES FACING ONE ANOTHER, A PLURALITY OF HIGH MAGNETIC PERMEABILITY, HIGH SATURATION MAGNETIZATION, CENTRAI CYLINDRICAL SPACERS POSITIONED AT EACH END OF SAID STACKED CENTRAL MAGNET ARRAY AND BETWEEN ADJACENT STACKED CENTRAL MAGNETS, AND A MAGNET ARRAY SUPPORT FOR MOUNTING SAID MAGNETS AND SAID SPACERS; AN INNER COIL ARRAY COMPRISING A PLURALITY OF CONCENTRIC CYLINDRICAL COIL WINDINGS POSITIONED ADJACENT TO SAID CENTRAL SPACERS AND SAID MAGNETIC POLES OF SAID CENTRAL MAGNETS, SAID INNER COIL WINDINGS SURROUNDING AN OUTSIDE PERIMETER OF SAID CENTRAL SPACERS, SAID INNER COIL ARRAY MOUNTED ON A MOVABLE COIL SUPPORT, SAID MOVABLE COIL SUPPORT PROVIDING FOR RECIPROCATING LINEAR MOTION OF SAID COIL ARRAY RELATIVE TO SAID MAGNET ARRAY; AND AN OUTER MAGNET ARRAY ASSEMBLY COMPRISING AN OUTER MAGNET ARRAY COMPRISED OF A PLURALITY OF AXIALLY-ALIGNED, STACKED CONCENTRIC TOROIDAL MAGNETS HAVING LIKE MAGNETIC POLES FACING EACH OTHER, SAID OUTER MAGNET ARRAY SURROUNDING SAID INNER COIL ARRAY, SAID STACKED OUTER CONCENTRIC MAGNETS BEING ALIGNED AND POSITIONED ESSENTIALLY COPLANAR WITH SAID STACKED CENTRAL CYLINDRICAL MAGNETS WITH THE MAGNETIC POLES OF SAID OUTER MAGNETS ALIGNED WITH AND FACING OPPOSING MAGNETIC POLES OF SAID CENTRAL CYLINDRICAL MAGNETS, AND A PLURALITY OF HIGH PERMEABILITY, HIGH SATURATION MAGNETIZATION, OUTER CONCENTRIC TOROIDAL SPACERS POSITIONED AT EACH END OF SAID STACKED OUTER MAGNET ARRAY AND BETWEEN ADJACENT STACKED OUTER MAGNETS, SAID OUTER MAGNET ARRAY ASSEMBLY ATTACHED TO SAID MAGNET ARRAY SUPPORT; WHEREIN A PREDETERMINED LOCATION, CONFIGURATION AND ORIENTATION OF SAID CENTRAL MAGNET MAGNETIC POLES, SAID CENTRAL SPACERS, SAID INNER COIL WINDINGS, SAID OUTER MAGNET MAGNETIC POLES AND SAID OUTER SPACERS PROVIDE FOR SUPERPOSITION OF A RADIAL COMPONENT OF A MAGNETIC FLUX DENSITY FROM A PLURALITY OF CENTRAL AND OUTER MAGNETS TO PRODUCE A MAXIMUM AVERAGE RADIAL MAGNETIC FLUX DENSITY IN THE INNER COIL WINDINGS; AND A VOLTAGE CONDITIONING CIRCUIT ELECTRICALLY CONNECTED TO SAID COIL WINDINGS, SAID VOLTAGE CONDITIONING CIRCUIT PROVIDING AN OUTPUT VOLTAGE AND OUTPUT CURRENT TO AN ELECTRICAL LOAD.





AN ELECTROMAGNETIC LINEAR GENERATOR AND REGENERATIVE ELECTROMAGNETIC SHOCK ABSORBER IS DISCLOSED WHICH CONVERTS VARIABLE FREQUENCY, REPETITIVE INTERMITTENT LINEAR DISPLACEMENT MOTION TO USEFUL ELECTRICAL POWER. THE INNOVATIVE DEVICE PROVIDES FOR SUPERPOSITION OF RADIAL COMPONENTS OF THE MAGNETIC FLUX DENSITY FROM A PLURALITY OF ADJACENT MAGNETS TO PRODUCE A MAXIMUM AVERAGE RADIAL MAGNETIC FLUX DENSITY WITHIN A COIL WINDING ARRAY. DUE TO THE VECTOR SUPERPOSITION OF THE MAGNETIC FIELDS AND MAGNETIC FLUX FROM A PLURALITY OF MAGNETS, A NEARLY FOUR-FOLD INCREASE IN MAGNETIC FLUX DENSITY IS ACHIEVED OVER CONVENTIONAL ELECTROMAGNETIC GENERATOR DESIGNS WITH A POTENTIAL SIXTEEN-FOLD INCREASE IN POWER GENERATING CAPACITY. AS A REGENERATIVE SHOCK ABSORBER, THE DISCLOSED DEVICE IS CAPABLE OF CONVERTING PARASITIC DISPLACEMENT MOTION AND VIBRATIONS ENCOUNTERED UNDER NORMAL URBAN DRIVING CONDITIONS TO A USEFUL ELECTRICAL ENERGY FOR POWERING VEHICLES AND ACCESSORIES OR CHARGING BATTERIES IN ELECTRIC AND FOSSIL FUEL POWERED VEHICLES. THE DISCLOSED DEVICE IS CAPABLE OF HIGH POWER GENERATION CAPACITY AND ENERGY CONVERSION EFFICIENCY WITH MINIMAL WEIGHT PENALTY FOR IMPROVED FUEL EFFICIENCY.


HOW IT WORKS


A CONVENTIONAL AUTOMOTIVE SHOCK ABSORBER DAMPENS SUSPENSION MOVEMENT TO PRODUCE A CONTROLLED ACTION THAT KEEPS THE TIRE FIRMLY ON THE ROAD. THIS IS DONE BY CONVERTING THE KINETIC ENERGY INTO HEAT ENERGY, WHICH IS THEN ABSORBED BY THE SHOCK’S OIL.
THE POWER-GENERATING SHOCK ABSORBER (PGSA) CONVERTS THIS KINETIC ENERGY INTO ELECTRICITY INSTEAD OF HEAT THROUGH THE USE OF A LINEAR MOTION ELECTROMAGNETIC SYSTEM (LMES). THE LMES USES A DENSE PERMANENT MAGNET STACK EMBEDDED IN THE MAIN PISTON, A SWITCHABLE SERIES OF STATOR COIL WINDINGS, A RECTIFIER, AND AN ELECTRONIC CONTROL SYSTEM TO MANAGE THE VARYING ELECTRICAL OUTPUT AND DAMPENING LOAD.
THE BOTTOM SHAFT OF THE PGSA MOUNTS TO THE MOVING SUSPENSION MEMBER AND FORCES THE MAGNET STACK TO RECIPROCATE WITHIN THE ANNULAR ARRAY OF STATOR WINDINGS, PRODUCING ALTERNATING CURRENT ELECTRICITY. THAT ELECTRICITY IS THEN CONVERTED INTO DIRECT CURRENT THROUGH A FULL-WAVE RECTIFIER AND STORED IN THE VEHICLE’S BATTERIES.
THE ELECTRICITY GENERATED BY EACH PGSA CAN THEN BE COMBINED WITH ELECTRICITY FROM OTHER POWER GENERATION SYSTEMS (E.G. REGENERATIVE BRAKING) AND STORED IN THE VEHICLE’S BATTERIES.

MANUFACTURING CONSIDERATIONS


MANUFACTURE OF THE POWER-GENERATING SHOCK ABSORBER WILL REQUIRE A MACHINED MAIN SHAFT WITH EMBEDDED PERMANENT MAGNET STACK, A STRONG AIR-GAP CYLINDER HOUSING, HIGH QUALITY STATOR WINDINGS, AND ROBUST SLIDE BEARINGS. OTHER SYSTEMS, SUCH AS MICROPROCESSOR-CONTROLLED VOLTAGE, CURRENT, AND DAMPENING REGULATION, EXTERNAL CASING, PROTECTIVE BELLOWS, ETC. WILL ALSO NEED TO BE DESIGNED AND TESTED.


REFERENCES

· WWW.HOWSTUFFWORKS.COM
· WWW.MRFLUIDS.COM
· EN.WIKIPEDIA.ORG
· WWW.CAR-STUFF.COM/MONROESHOCKS.HTM

    14 comments:

    I enjoy reading a lot and your stories are worth reading, nice blog, keep it up.

    Moisture Management

    A CHAIN OF MORE THAN TWO MAGNETS CAN BE USED TO TOLERATE THE SHOCKS OR WEIGHT AND MAKE THE VEHICLE MORE COMFORTABLE.

    I enjoy reading a lot and your stories are worth reading, nice blog, keep it up.

    i like the absorption system

    Why use magnetic fluid at all? Why not just calibrate two opposing magnets that create sufficient repell under any force? Would the ride be too stiff when not under duress? This would eliminate the need for electronics, fluid, computers, lending a simple implementation to physical mechanical. Why not? Cost? Not sure what the fluid is providing beyond variable tensile strength.

    i agree...but i feel for a luxury car or a sports car it would make sense to have a computer to calculate the compression and react according to the situation...but why fluid???? btw what fluid?? ferro-fluid?? anyway for a normal car it doen't make sense to have a fluid or computers to do the calculations....


    P.S.--this thing is very intriguing....I'll take it up as a project this year in college.

    Great article which explains details about MR which I already knew however here you give more detailed/better explanation than any other article I have come across on the NET.

    I have interest in this because I have developed a range of kits which improves ride comfort and handling of the Audi MagneRide System. My kit is MSS Spring Kits – see www.mssspringkits.com or visit our Facebook page at https://www.facebook.com/MSSSpringKits.

    I aim to adapt MSS Spring Kits for other semi-active damper systems used on BMW; Porsche and VW cars.

    this is greatly informative stuff man. This is simpley going to get a hi 5.. These can go with great efficiency with the cars as well.
    tyres Douglas

    Hey i would like to make a magnetic shock absorber as my final year project for enggineering . Could u pls give me the guideliness about strength of magnet needed etc ..

    wow really nice explanation of shock absorber parts in detail. Even i have seen that shock absorber pistons are of best use for any machinery type.

    I have watched a lot of articles regarding information for Truck on leveling kits, Suspension and other parts of a Truck for customization.
    I found similar website which has similar information and also a lot of lift kits and other information. The information of http://prestigecustomrides.com/ is really attractive rather than I found from local market.

    Your work article, blogs I mean over all contents is must read material.mechanic

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