The present invention relates generally to a suspension system. More particularly, this invention relates to a magnetic suspension system, which eliminates mechanical contact between the wheel and the chassis of a vehicle. Further, the present invention eliminates the need for a spring or damper.

BACKGROUND OF INVENTION

Suspension is generally a system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. The suspension system serves a dual purpose contributing to the vehicle's road holding / handling and braking for continuous safety and driving pleasure. It also provides the vehicle's occupants a ride that is comfortable and also reasonably well isolated from road noise, bumps, vibrations etc.

The spring absorbs the shock created due to a bump or pothole on the road and stores it in the form of energy, without jarring the passengers of the car. Most of the cars have four springs made from spring steel and are wound in a spiral shape. Some vehicles have transverse springs and are made from fiberglass or other composite materials. However, the springs often suffer from 'Fatigue' which is attributed to the factors such as bad roads, change in temperature due to weather, presence of moisture in the atmosphere and corrosion. Due to continuous compression and tension experienced by the spring said spring gradually becomes too soft. In such a case, the vehicle will drop to that particular side, which affects the steering mechanism causing an accident. Another constraint is that the stiffness of the spring remains essentially constant. In this case, the suspension will not effectively absorb the shock offered by the terrain and transmits some fraction of the shock to the chassis and also too much of vibration under resonance cause failure of certain joints.

To provide a comfortable ride, the damper is incorporated to moderate the energy stored in the spring and reduces the number and amplitude of oscillations that occur between the initial bump and the return of the spring to the rest position. Hydraulic damper unit is used to dissipate the energy stored by pumping oil through small orifices. Resistance offered by the damper unit increases with increase of the speed of spring deflection. However, the continuous motion of the damping fluid inside the damper unit causes it to heat up and eventually loses its properties like viscosity which alters the ride characteristics. Therefore, there is a need for the frequent replacement of the damping fluid. The damping fluid, which is continuously compressed inside the damping chamber due to the reciprocating action of the wheel, exerts tremendous amounts of hoop / circumferential stress on the walls of the damping chamber, aiding the propagation of a crack through which the damping fluid eventually leaks, causing a choppy ride. Basically the spring and the damper unit work by using friction / viscosity as the helping agent which is extremely undesirable. The friction causes wear and after a period of time, some portion of the component is lost and stresses induced in the shock absorber unit are high. Therefore, there is a need to constantly have a check on the damper / spring.

CN202402539 discloses a permanent magnet suspension shock absorber special for an electric automobile, which comprises of a connection support column and an outer dustproof cover which are connected. A damping tappet rod and a cylinder are arranged in the outer dustproof cover, the damping tappet rod is respectively connected with the outer dustproof cover and damp connected with a suspension end magnet, and the cylinder is connected with a fixed end main magnet.

CN 102358125 discloses a magnetic suspension which comprises a vehicle beam and carriage axles, wherein a suspension is arranged on the carriage axles, a guide sleeve is fixedly arranged on the suspension, two permanent magnets with opposite polarities are arranged in the guide sleeve and arranged on the bottom of the guide sleeve, one permanent magnet is movably arranged above the other permanent magnet, guide pillars are fixedly arranged under the vehicle beam, the lower ends of the guide pillars are movably arranged on the permanent magnets in the guide sleeve.

227/MUM/2012 discloses a magnetic force shock-absorbing device. The device comprises a cylindrical casing, cylindrical shaped magnet, ring shaped magnet and a piston. When the vehicle experiences the sudden shock, movable rod slides vertically inside the cylinder along with the magnet. The same poles of the fixed and movable magnets are creating the strong repulsive force. This repulsive force is used for absorbing the heavy shock load and magnetic shock absorber will act as a damping device for vehicle.

CN2474372 discloses a magnetic levitation absorber comprising an inner rod, an outer cover rod and a fixed cover, wherein the fixed cover is provided with a central hole, and an upper magnet is fixedly provided at the lower end of the inner rod. A lower magnet is provided at the bottom of the inner side of the outer cover, and the middle portion is provided with a suspending magnet. The polarity among the magnets is in phase located, and the magnets produce repellant with each other, thereby achieving the purpose of vibration damping.

Magnetic shock absorbers with two magnets are placed in a piston. One magnet is fixed with piston. Another one is movable, which is connected with rod. The magnetic shock absorber works on the basic principle of magnet that "opposite poles attract each other and same poles repel each other". (S. Gopinath., RJ.Golden renjith., and J. Dineshkumar. International Journal of Engineering & Technology, 3 (2) (2014) 208-211).

Magnetic shock absorber comprises of two circular magnets and a rod. 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. (Kalpita patil. Third National Technological Innovations & Traditional Knowledge Awards (192-193)).

However, the magnetic suspension as disclosed in the prior arts fails to achieve different types of damping as like mechanical suspension.

Accordingly, there exists a need for a magnetic suspension system, which eliminates mechanical contact between the wheel and the chassis of a vehicle and eliminates the need for a spring or damper. OBJECTS OF INVENTION

One or more of the problems of the conventional prior art may be overcome by various embodiments of the system and method of the present invention.

Accordingly, it is the primary object of the present invention to provide a magnetic suspension system, which eliminates mechanical contact between the wheel and the chassis of a vehicle.

It is another object of the present invention to provide a magnetic suspension system, which eliminates the need for a spring or damper.

It is another object of the present invention to provide a magnetic suspension system, which can be used in different types of vehicles by changing intensity and size of the magnet.

It is another object of the present invention, wherein the shock absorptivity is more efficient when compared to conventional spring and damper type.

It is another object of the present invention, wherein the stiffness of the magnetic suspension system is continually variable depending upon the distance of separation between the magnets.

It is another object of the present invention, wherein the system also acts as a generator.

SUMMARY OF INVENTION

Thus according to the basic aspect of the present invention there is provided a magnetic suspension system, comprising of:

an housing, said housing houses at least two magnets and piston comprising piston rod and piston head;

an enclosing disc; and

at least two bearings,

wherein the housing is enclosed by an enclosing disc at its top,

wherein the magnets are positioned one above the other inside the housing, said magnets having either of like poles facing each other,

wherein the magnet positioned at bottom face of the housing is fixed magnet,

wherein the magnet positioned above the fixed magnet is levitating magnet, wherein one end of the piston head is inserted into the housing to rest on the levitating magnet and gets supported by the fixed magnet,

wherein other end of the piston head with the piston rod is provided with the bearing, said bearing is attached to hub of a wheel,

wherein other end of the housing is provided with the bearing, said bearing is attached to chassis of a vehicle, and

wherein weight of the vehicle causes the distance of separation between the magnet to decrease, causing an increased repulsive force between the magnets.

It is another aspect of the present invention, wherein the levitating magnet which moves through the housing with a velocity during an impact of an obstacle or during influence of gravity induces movement of electrons resulting in a current.

It is another aspect of the present invention, wherein said current decelerates the levitating magnet movement inside the housing.

It is another aspect of the present invention, wherein magnetic field created by the current repels the movement of the levitating magnet inside the housing, decelerating the fall and decreasing the amplitude of vibration.

It is another aspect of the present invention, wherein the current produced can be harnessed by storing the current in a battery of the vehicle.

It is another aspect of the present invention, wherein the wheel movement causes the piston to move, which makes the levitating magnet to travel closer to the fixed magnet, reducing the distance of separation.

It is another aspect of the present invention, wherein if a load is applied on the vehicle, the distance of separation decreases till the repulsive force becomes equal to the weight of the vehicle along with the load applied on the vehicle. It is another aspect of the present invention, wherein the magnet levitates inside the housing due to the repulsive force which is inversely proportional to the second degree of distance of separation.

It is another aspect of the present invention, wherein damping is achieved in a magnetic suspension system by increasing or decreasing the clearance between the housing and the magnets.

It is another aspect of the present invention, wherein the damping ratio is within the range of 0.2- 0.4.

It is another aspect of the present invention, wherein stiffness of the magnetic suspension system is continually variable depending upon the distance of separation between the magnets.

It is another aspect of the present invention, wherein said piston head is detachably attached to the piston rod.

It is another aspect of the present invention, wherein the enclosing disc act as a mechanical guide by integrating the piston and housing, and restrains the movement of the piston rod to oscillate only along the required axis.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 : illustrates the sectional view of a magnetic suspension system according to the present invention.

Figure 2: illustrates the sectional enlarged view of magnets constrained in the magnetic suspension system when load acts on it according to the present invention.

Figure 3: illustrates the exploded view of a magnetic suspension system with three magnets according to one embodiment of the present invention.

Figure 4: illustrates the sectional view of a magnetic suspension system with parallel arrangement according to another embodiment of the present invention.

Figure 5: illustrates the force vs. deflection graph when load acts on the magnetic suspension system according to the present invention. Figure 6: illustrates the stiffness vs. displacement graph when load acts on the magnetic suspension system according to the present invention.

Figure 7: illustrates the force vs. deflection graph when load acts on the magnetic suspension system and spring type suspension.

Figure 8: illustrates the stiffness vs. displacement graph when load acts on the magnetic suspension system and spring type suspension.

Figure 9: illustrates the damping graph when load acts on the magnetic suspension system according to the present invention.

Figure 10: illustrates the exponential decrement curve for the damped oscillations of the magnetic suspension system according to the present invention.

Figure 11: illustrates the logarithmic decrement graph for the obtained value of damping ratio of the magnetic suspension system according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

The present invention as discussed hereinbefore relates to a magnetic suspension system, which eliminates mechanical contact between the wheel and the chassis of a vehicle. Further, the present invention eliminates the need for a spring or damper.

Referring to Figure 1, the magnetic suspension system comprises of housing [1] which is cylindrical, said housing [1] houses at least two magnets [2a, 2b]; and piston, said piston comprising piston rod [4] and piston head [3]. The housing [1] is enclosed by an enclosing disc [6] fastened at one end using one or more fasteners [7] into respective slots [8] in the housing [1]. The magnets [2a, 2b] are positioned one above the other inside the housing [1], said magnets [2a, 2b] having either of like poles facing each other. The magnet [2a] positioned at bottom face of the housing [1] is fixed magnet and the magnet [2b] positioned above the fixed magnet [2a] is levitating magnet.

The inner diameter of the housing [1] is lesser than the hypotenuse of the magnets [2a, 2b] to prevent toppling of the magnets [2a, 2b]. One end of the piston head [3] is inserted into the housing [1] to rest on the levitating magnet [2b] and gets supported by the fixed magnet [2a]. Appling any force on the magnet [2a] creates a Repulsive Force (FR) on the magnet [2b]. Similarly, the magnet [2b] also exerts the same repulsive force on the magnet [2a]. When the applied force becomes greater than the repulsive force exerted by the magnets [2a, 2b], the distance of separation between the magnets [2a, 2b] decreases till the repulsive force annuls the applied force.

The enclosing disc [6] act as a mechanical guide by integrating the piston and housing [1], and restrains the movement of the piston rod [4] to oscillate only along the required axis. The enclosing disc [6] is guided by the piston rod [4] to reach the open face of the housing [1] through respective slot on the enclosing disc [6]. The other end of the piston head [3] is provided with the piston rod [4] with a bearing [5 a], said bearing [5 a] at the piston rod [4] end is attached to the hub of the wheel. The enclosing disc [6] is provided with a protrusion with a slot in centre of it so as to accommodate the bearing [5a]. The enclosing disc [6] prevents the magnets [2a, 2b] and piston from popping out of the housing [1].

In one aspect, the piston head [3] and the piston rod [4] are detachably attached to the respective bearings [5a] and [5b]. A central hole is drilled in the piston head, after which internal threading is performed in the formed hole. The free end of the piston rod [4] is threaded externally using the same pitch as the internal thread of the piston head. Hence, they can be attached and detached whenever required. Therefore, whenever worn out, the piston head [3] alone can be replaced instead of replacing the whole piston.

The piston acts as a mechanical linkage between the levitating magnet [2b] and open face of the housing [1]. The other end of the housing [1] is provided with a bearing [5b], said bearing [5b] is attached to chassis of a vehicle. It is to be understood that the suspension system may be placed in a transverse or an inclined manner depending upon the design of the vehicle. Weight of the vehicle causes the distance of separation between the magnets [2a, 2b] to decrease, causing an increased repulsive force between the magnets [2a, 2b] as shown in Figure 2. The distance of separation decreases as long as the repulsive force becomes equal to the weight of the vehicle. Once the required repulsive force is created by the magnets [2a, 2b], equilibrium is attained. If a load is applied on the vehicle, the distance of separation decreases further till the repulsive force becomes equal to the weight of the vehicle along with the load applied on the vehicle.

For illustration, when the wheel hits a bump, the wheel moves upwards causing the piston [3, 4] also to move upwards making the levitating magnet [2b] to travel closer to the fixed magnet [2a], reducing the distance of separation. As repulsive force is inversely proportional to the square of distance of separation, at equilibrium condition, the repulsive force must be equal to the force experienced by the vehicle due to the bump. Hence, the levitating magnet [2b] travels some distance (reducing the distance of separation) that is required to cause the required repulsive force. The levitating magnet [2b] levitates inside the housing [1] due to the repulsive force which is inversely proportional to the second degree of distance of separation hence, it does not transmit much impact to the chassis of the vehicle that is required to feel the bump and shock absorptivity of the magnetic suspension system is more effective compared to conventional spring and damper type suspension system where the restoring force exerted by the spring is inversely proportional to the first degree of the distance of separation. That is, the wheel would travel greater distance to completely absorb the shock which the conventional spring does not.

The housing [1] is a hollow cylindrical housing made of materials which are non-magnetic but conducts electricity. The non-magnetic material includes but not limited to aluminum, copper, silver, tin ensuring that the whole suspension system is light weight and does not contribute to the unsprung mass of the vehicle. The inner surface of the housing [1] is preferably hard anodized in order to provide a surface that is scratch and wear resistant so that the magnets [2a] and [2b] and the housing [1] do not lose their dimensions after prolonged usage. The levitating magnet [2b] which moves through the housing [1] with a velocity during an impact of an obstacle or during influence of gravity induces movement of electrons resulting in current, said current decelerates the levitating magnet [2b] movement inside the housing [1]. The magnetic field created by the current repels the movement of the levitating magnet [2b] inside the housing [1], decelerating the fall and decreasing the amplitude of vibration. This phenomenon is used in the magnetic suspension system in a real-time application as a damper. The damping force is directly proportional to the velocity of movement of the levitating magnet [2b] . The current produced can be harnessed by storing the current in a battery of the vehicle and therefore, the magnetic suspension system also acts like a generator. At that instant where the obstacle has just been crossed, the repulsive force is greater than the force due to the weight of the vehicle. Therefore, the magnets [2a, 2b] repel away to the distance of separation which causes the repulsive force equal to the weight of the vehicle. Hence, the suspension system acts like a spring. As the magnets [2a, 2b] lose their magnetic intensity only at elevated temperatures like 90°C, the heat produced due to friction is dissipated by the housing [1] at a very high rate which is attributed to the high convective heat transfer coefficient of metals. The type of damping whether it is under-damped / critically damped / over-damped can be achieved in a magnetic suspension system by increasing or decreasing the clearance between the housing [1] and the magnets [2a, 2b] .

The amplitude of the vibration caused by the impact is reduced / damped by Lorentz Force which opposes the fall of the levitating magnet [2b] through the housing [1]. The wheel movement causes the piston to move, which makes the levitating magnet [2b] to travel closer to the fixed magnet [2a], reducing the distance of separation. The stiffness of the magnetic suspension system is continually variable depending upon the distance of separation between the magnets. For illustration, if the configuration of the obstacle is such that it has a gradual increase in its height, the rate of change of velocity V is less and also the damping due to the Lorentz Force is not significant. If the obstacle has a sudden increase in its height, the rate of change of velocity of the moving magnet is also high which causes a larger damping force in the suspension system, which provides a comfortable ride to the driver i.e., the suspension acts 'sensibly' based on the obstacles it faces.

Further, the system is customizable (shock absorbers in series / parallel). Users can attach two magnetic suspension systems in parallel to each wheel hub instead of one for the load acting on the suspension system gets shared equally by both and the net load experienced by the individual suspension is half of what it would be had the number of suspension systems attached to each hub been one. More number of magnets can be stacked one on top of the other to increase the shock absorptivity and wheel travel of the magnetic suspension system. In order to withstand higher load, the suspension system can be inclined at some angle to the ground. Inclination causes the load acting along the suspension axis to be decreased, thereby making it usable in real-scale applications.

Referring to Figure 3, in one embodiment, the magnetic suspension system comprises of cylindrical housing [1], said housing [1] houses at least three magnets [2a, 2b, and 2c]; and piston comprising piston rod [4] and piston head [3]. The housing [1] is enclosed by an enclosing disc [6] fastened at one end using one or more fasteners [7] into respective slots [8] in the housing [1]. The magnets [2a, 2b, and 2c] are positioned one above the other inside the housing [1], said magnets [2a, 2b, and 2c] having either of like poles facing each other. The magnet [2a] positioned at bottom face of the housing [1] is fixed magnet, the magnet [2b] positioned above the fixed magnet [2a] and the magnet [2c] positioned above the magnet [2b] are levitating magnets.

The inner diameter of the housing [1] is lesser than the hypotenuse of the magnets [2a, 2b and 2c] to prevent toppling of the magnets [2a, 2b and 2c]. One end of the piston head [3] is inserted into the housing [1] towards the levitating magnet [2c] and gets supported by the levitating magnet [2b]. The diameter of the piston head [3] is slightly smaller than the inner diameter of the housing [1] so that the piston can smoothly slide inside the housing [1]. When the applied force becomes greater than the repulsive force exerted by the magnets [2a, 2b, and 2c] , the distance of separation between the magnets [2a, 2b, and 2c] decreases till the repulsive force annuls the applied force.

The enclosing disc [6] act as a mechanical guide by integrating the piston and housing [1], and restrains the movement of the piston rod [4] to oscillate only along the required axis. The other end of the piston head [3] is provided with the piston rod [4] with a bearing [5a], said bearing [5a] at the piston rod [4] end is attached to the hub of the wheel. The other end of the housing [1] is provided with a bearing [5b], said bearing [5b] is attached to chassis of a vehicle. For illustration, When 'n' number of magnets are stacked one on top of the other such that the following pole sequence is obtained ([N-S] [S-N] [N-S] [S-N]... ), then the total travel of the suspension would be [(n-l)*x] where 'x' is the maximum possible travel of one pair of magnets. Hence, the vehicle can now travel in more harsh regions where a wheel may have to climb over rocks with pre-determined diameter. Stiffness of the magnetic suspension system can be varied achieved by changing the combination of magnets (high intensity and low intensity).

Another way to increase the load withstanding capability of the magnetic suspension system is slightly modifying the design in order to accommodate the magnets in parallel arrangement.

Referring to Figure 4, in another embodiment, the magnetic suspension system with parallel arrangement comprising of cylindrical housing [1], said housing [1] is provided with four parallel guide ways with at least three magnets [2a, 2b, and 2c] ; and piston comprising piston rod [4] and piston head [3] in respective parallel guide way. The housing [1] is enclosed by an enclosing disc [6] fastened at one end using one or more fasteners [7] into respective slots [8] in the housing [1]. The magnets [2a, 2b, and 2c] are positioned one above the other inside the respective guide way [1], said magnets [2a, 2b, and 2c] having either of like poles facing each other. The magnet [2a] positioned at bottom face of the respective guide way [1] is fixed magnet, the magnet [2b] positioned above the fixed magnet [2a] and the magnet [2c] positioned above the magnet [2b] is levitating magnet.

One end of the piston head [3] is inserted into the guide way towards the levitating magnet [2c] and gets supported by the levitating magnet [2b]. When the applied force becomes greater than the repulsive force exerted by the magnets [2a, 2b, and 2c], the distance of separation between the magnets [2a, 2b, and 2c] decreases till the repulsive force annuls the applied force.

The enclosing disc [6] act as a mechanical guide by integrating the piston and housing [1], and restrains the movement of the piston rod [4] to oscillate only along the required axis. The other end of the respective piston head [3] is provided with the piston rod [4] with a bearing [5a], said bearing [5a] at the piston rod [4] end is attached to the hub of the wheel. The other end of the housing [1] is provided with a bearing [5b], said bearing [5b] at the other end of the housing [1] is attached to chassis of a vehicle.

Test Results

The magnetic suspension with at least two magnets according to the present invention is tested for the following parameters:

• Performance

• Damping

• Customizable

PERFORMANCE ANALYSIS OF THE MAGNETIC SUSPENSION:

Three magnets are placed instead of two so as to increase the travel of the suspension. It can be noted that for magnets of the same size, but grade N52 (highest grade available), the maximum load absorbable by the suspension would be equal to 45kgf (maximum load at '0' distance of separation between magnets). Hence, by just changing the magnets, the performance of the shock absorber can be altered as required by the application.

Force Vs Deflection / Displacement

The magnetic suspension system is tested using a suspension test rig to find Force (F) vs. Displacement (x) test. The test rig comprises of a displacement sensor (which measures the displacement of the piston with the body fixed), a pneumatic pressure pump (which applies the load) and data acquisition instruments that are connected to a computer. The results show the displacement of the piston from the initial position (zero load applied) corresponding to an applied load. In that manner, many values of the load and the corresponding displacement are noted by the data acquisition programs and the values are given as output. The force vs. deflection graph is plotted by plotting the force along the y-axis and the displacement along the x-axis as shown in Figure 5. The tests yielded the following readings as shown in Table- 1 given below: Table- 1:

The displacement / deflection were found to be proportional to the third degree of force, which confirms that the magnetic suspension system compresses easily until a particular load (say 'L' kgf.) and when the load increases beyond 'L', the suspension acts as a stiff one, which causes the compression to decrease tremendously. This trend can also be observed in the readings. It can be observed that when the load increases from 0.83kgf to 1.8kgf, the deflection observed in the suspension was 19.5mm; whereas, when the load increased from lOkgf to l lkgf, the deflection observed was only 1.7mm. This confirms that the point that was earlier referred to as 'L' lies somewhere between these values.

Upon further inspection, it can be concluded that the slope of the angle made by the tangent at every point with the x-axis increases rapidly when the deflection is approximately in the range of 23mm-30mm. This point (L) beyond which the suspension acts as a stiff one is termed 'transition point'.

Stiffness:

The stiffness equation is obtained by plotting a graph between stiffness and displacement. This graph yields the value of stiffness at any position/displacement of the piston. The graph is plotted by obtaining the instantaneous stiffness value which is obtained by dividing the load with the deflection observed as shown in Figure 6. This value of instantaneous stiffness at various displacements is plotted against the displacement. The readings are tabulated as shown in Table- 2.

Table- 2:

From the graph illustrated in Figure 6, it is noted that the magnetic suspension system is initially soft and then stiffens after the transition point. Hence, it is important to determine this transition point so that further calculations can be done. Differentiating the stiffness equation with respect to displacement would give the rate of change of stiffness with respect to displacement. Hence, using the mathematical concept of Maxima and Minima, the point where the rate of change of stiffness is the maximum can be determined and this point would be the transition point, as per the definition of it.

COMPARISON OF PERFORMANCE OF THE MAGNETIC SUSPENSION SYSTEM AND CONVENTIONAL AIR-SPRING TYPE SUSPENSION

Force Vs Deflection / Displacement

The magnetic suspension system and air spring type suspension is tested using a suspension test rig to find Force (F) vs. Displacement (x). The force vs. deflection graph is plotted by plotting the force along the y-axis and the displacement along the x-axis as shown in Figure 7. The tests yielded the following readings as shown in Table- 3 given below:

Table- 3: x disp Magnetic

(mm) Suspension Air spring

0 0.83 0.355

6.123 1.1 1.16

12.25 1.4 1.978 18.4 1.75 2.559

24.5 2.2 3.244

30.5 3 4.65

36.76 5.33 6.751

42.88 9.5 11.04

49 15.7 15.7

Stiffness:

The stiffness equation is obtained by plotting a graph between stiffness and displacement magnetic suspension system and air spring type suspension with same load applied. This graph yields the value of stiffness at any position/displacement of the piston. The graph is plotted by obtaining the instantaneous stiffness value which is obtained by dividing the load with the deflection observed as shown in Figure 8. This value of instantaneous stiffness at various displacements is plotted against the displacement. The readings are tabulated as shown in Table- 4.

Table- 4:

It is evident that the magnetic suspension system is softer than the air spring type suspension before the transition region as shown in Figure 7, and the stiffness value increases more rapidly after the transition region as shown in Figure 8. Hence, the performance of the magnetic suspension system is clearly better than the air spring type suspension.

DAMPING TEST OF THE MAGNETIC SUSPENSION

For the damping test, the three magnet type magnetic suspension system is converted into a two magnet type magnetic suspension system because of the simplicity. Moreover, the damping force is only proportional to the velocity of the piston, and does not depend on the travel of the suspension or the mass of the deadweight. Hence, it can be said that the damping force does not depend upon the stiffness as stiffness is the ratio of the load added and the displacement produced by it.

The damping test setup constructed using ultra slow motion cameras that capture motion 64 times slower than the actual. Deadweight of 5kg was taken and was held exactly on top of the piston, making sure that the piston does not experience any load and is not supported by it. A displacement sensor is attached to the end of the piston so that it would record the displacement of the piston. The mean position is defined as that position where the piston would deflect to when a certain load is added. Once the load is released, the piston reciprocates back and forth for a few times before coming to a stop. In practice, the piston cannot be allowed to reciprocate at its own will because it would cause problems to the vehicle handling. Hence, the damper comes into play and reduces/dampens the oscillation of the piston. Hence, the time period of each individual oscillation and the deflection is observed.

The test was conducted and the values of displacement and the time taken to reach that point were noted as shown in Table- 5 using the slow motion camera. Table- 5:

The logarithmic decrement graph was obtained by plotting the results as shown in Figure 9. The graph obtained resembles the logarithmic decrement graph of any damper system and hence, the magnetic suspension system acts as a damper is proven to be true.

To find out the damping ratio, values of displacement are plotted above the mean displacement (represented by the 0 in y-axis) as shown in Figure 10. Hence, the values were noted as shown in Table- 6.

Table- 6:

The system of the present invention is under damped with damping ratio k=0.3443 and k<l. Hence, the damping ratio is within the range of 0.2-0.4 to provide comfortable ride to the vehicle. The logarithmic decrement graph for the obtained value of damping ratio (0.3443) is shown in Figure 11. From the graph it is clear that the curve corresponding to the logarithmic decrement curve for a damping ratio of 0.4 is very close to the curve obtained in the magnetic suspension system of the present invention. Hence, it can be concluded that the magnetic suspension system is better that the actual spring and damper type suspension in performance, maintenance, life and customizability.

The embodiments of the invention been disclosed in detail in this specification are purely for illustrative purposes and the present invention can be embodied in many other forms or carried out in other ways, without departing from the spirit or essential characteristics thereof. It is understood that the invention is not limited thereto, but is susceptible of numerous changes and modifications as known to those skilled in the art, and all such variations or modifications lies within the scope of the present invention.

Advantages of the present invention are as follows:

• Eliminates mechanical contact between the wheel and the chassis of the vehicle, while creating an alternate durable and reliable linkage (suspension body and the piston).

• Eliminates the need for a spring or damper.

• Mass production techniques can be easily used to increase the produce of the required components.

• Stiffness of the magnetic suspension system is continually variable depending upon the distance of separation between the magnets hence result in a ride that is both comfortable and safe.

• The stiffness or the loading capacity of the vehicle can be changed by just changing the combination of the magnets (high intensity and low intensity).

• Unlike the springs, which are constantly subjected to continuous dynamic forces, causing stress in the material, the magnets do not suffer any stress. Hence, the life of the Magnetic suspension is much higher than that of the any available prior arts.

• The magnetic suspension has the potential to produce small amounts of electricity, which can power the electronic components of the vehicle.

• Unlike the conventional suspension, where a given damper has the same qualities throughout its life, the damping parameters of the magnetic suspension system can easily be altered by just changing the thickness of the suspension housing. • Offers a great deal of customizability and the range of its application itself is very broad and can be used in any field.

• When multiple magnets are used inside the body, the suspension travel of the Magnetic suspension is increased, which is not possible in any conventional system.

• When multiple columns of magnets (say 'n') are used in the housing, the load withstanding capacity of the magnetic suspension is also increased by 'n' times.