Patent Abstract:
A vehicle with zero turning radius employing a minimum of two generally parallel matching annular wheels mounted with independent pneumatic toroidal suspensions fixed coaxially on a chassis. The wheels have mounted on their inner hub sides frictional linings along which run a respectively equal number of circumferentially distributed truncated-bicone-shaped rotors of brush-less dc motors with stator shafts fixed on to the axles of the wheels. Addition of a number of large holonomic wheels in tandem on either side of the two generally parallel wheels makes the vehicle longer and more stable. The large holonomic wheels have tires formed by a toroidal unanimity of disc-like rollers with magnetic or electromagnetic elements radially distributed evenly to make each disc-like roller rotate or resist rotation perpendicular to the holonomic wheel axis by acting as a rotor to motor stator windings attached to the chassis in proximity with the ground-engaging portion of the tire.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Present application is a continuation in part of U.S. patent application Ser. No. 09/781,090 filed on Jan. 12, 2001. The matter disclosed in the present application formed the amendment to application Ser. No. 09/781,090, received by the United States Patent and Trademark Office on Sep. 1, 2004. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable  
       REFERENCE TO A MICROFICHE APPENDIX  
       [0003]     Not Applicable  
       BACKGROUND OF THE INVENTION  
       [0004]     The present invention is directed to the field of electrical motor vehicles with zero turning radius. It also relates to those vehicular designs in which steering of the vehicle is not done by moving the axles of the wheels.  
         [0005]     There had been designs in the past, which utilized an electric motor inside the wheel. On many occasions the wheel is turned into a wheel motor (U.S. Pat. No. 5,894,902). But as there are no gears in the case of a direct-driven wheel motor, in order to generate a high torque, either the diameter or the thickness of the wheel motor has to be increased: This makes the wheel motor heavy. To hold together wheels with wheel motors, the axles and the chassis (or the shell) both have to be stronger and heavier than in a vehicle driven by a centrally located power pack.  
         [0006]     How to do away with the numerous mechanical parts, which weigh down an electric motor vehicle? Moreover, how to reduce the rolling friction to reduce the cruising power requirement of an electric motor vehicle? These were the two major pointers leading to this invention. U.S. Pat. Nos. 4,163,567 and 4,192,395 disclose vehicles, which opened a way to finding suitable answers. The rigid coaxial nature of the two parallel wheels in those vehicles restricts the use of the vehicles to low traveling speeds. Further, the electrical drive motors for the two wheels are located outside the wheel hubs, which limits the number of motors used to drive each wheel without sacrificing useful windscreen width of the vehicles. The bearings of the annular wheels have no provisions to protect against foreign materials from getting into their engaging surfaces. The use of very large wheels does not eliminate other driving mechanisms outside the wheels, excepting a separate steering mechanism. The rigidity of the mounting of annular wheels on vehicle frame does not take into account, momentary radial impacts on the wheels while rotating as the vehicle travels. These impacts bring about point distortions in the wheel, increasing the friction in the rotation of the wheels.  
         [0007]     On factory shop floors, there is a need for simple, low-maintenance traction vehicles of high maneuverability. A two-wheel design improves the negotiability of such a traction vehicle, if necessary features are built into existing art. The most important sought-after feature is to eliminate the need to reverse the vehicle to effect traction. Universal platforms or holonomic wheels are capable of smooth front-rear interchangeability; but they all have more complex tire structures, and have to be necessarily of more than two wheels (U.S. Pat. No. 4,715,460).  
         [0008]     The construction of a two-parallel-wheeled vehicle is restricted by the maximum diameter a practical annular wheel can reach without sacrificing structural strength. For to have more carrying ability or to have more space in a vehicle with no conventional steering or driving mechanism, holonomic wheels are promising. U.S. Pat. Nos. 4,335,899, 4,598,782, 4,715,460, 5,246,238, 5,312,165 and 6,547,340 disclose evolving designs in holonomic wheel design. Except in U.S. Pat. No. 6,547,340, rest of the designs fail to compensate for the uneven wear in the rollers in case of rectilinear motion by the vehicle having such wheels. However, in U.S. Pat. No. 6,547,340, there is no control over the necessary rotation of each roller after it leaves ground contact as the holonomic wheel rotates and the vehicle travels. Further, the scheme of positioning of rollers in a four-wheeled vehicle (U.S. Pat. No. 4,598,782) always generates forces which are not in the direction of actual travel of the vehicle. These forces are also cancelled by the unique positioning. However, not before they have exerted bending stresses on each of the axles of the holonomic wheels. In addition, the workings of the design also depend upon the uniformity of the ground friction each of the wheels experiences. Nonuniform ground friction has to be compensated for by varying wheel rotation in response, as there is no direct control over the rollers on the holonomic wheels of existing art.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     This invention solves the earlier problems by first increasing the diameter of wheels. In the first version, the wheels, two in number, get integrated with the shell of the vehicle, dispensing with the solid axle of existing electrical vehicles. The shell of this electric motor vehicle is basically in the form of a modified cylinder with crush zones added on the front and the rear of the vehicle, a portion of the cylindrical side of which faces the surface on which the vehicle travels; both ends of the modified cylinder remain vertical, and these two ends also act as openings with partial or full doors. The two wheels in annular form are mounted on the two ends, with the use of toroidal pneumatic flexible mounts. These mounts allow axle formations to deflect in sympathy with radial deflections happening due to impacting forces acting on the tires; and the flexible mounts absorb the deflections, preventing them from distorting the wheels or the axle formations. The modified cylindrical shell of the vehicle thus acts as the axle formation for both the wheels. The electrical energy storage devices are kept near that surface of the shell the other side of which always faces the ground; the positioning of the electrical energy storage devices makes the center of gravity of the vehicle low and lends stability to the design—this is possible, because all the electrical energy accumulators and superconductor assemblies are heavy. Numerous lightweight brush-less dc motors housed in biconic rotors circumferentially locate rotatably the inner annular surface of both the wheels. Both the wheels are driven by individual switching regulators powering the BLDC motors, also effecting regenerative braking when needed. Steering is accomplished by differential rotation of the respective wheels.  
         [0010]     Thus, this invention avoids the use of gears, a mechanical steering, suspensions and pneumatic tires; it has a much greater torque-generation capability compared to motor-wheel designs. The rolling coefficient of friction is low, because the chord-versus-the-wheel-circumference ratio is low due to the increased effective diameter of the wheel.  
         [0011]     The second version of the present invention forms a traction vehicular arrangement. In this form, by adjusting the height of the passenger seat to a low it can be turned into a vehicle similar to the version described hereinabove. Otherwise, the traction vehicular arrangement functions in conjunction with wheeled trailers. It is equipped with a hook on the front and the rear. The passenger seat can be rotated vertically to make the occupant of the seat sit facing the opposite side. This effectively makes this vehicle with an interchangeable front and rear. Both ends of the modified cylinder in this version of the present invention are not used as doors; rather, they are blocked by the annular laminar extension of the hub of the wheels nearly reaching the central axis. This way the entry of foreign material can be blocked completely from entering the bearing and driving mechanisms of the wheels.  
         [0012]     The third version of the present invention makes use of holonomic large wheels arranged in tandem with the basic configuration described hereinbefore. Rollers are arranged uniformly on the rim of each holonomic wheel, with their axes perpendicular to the main axis of each holonomic wheel. Each roller has electromagnetic elements to make them function as rotors to an externally placed set of stators of a permanent magnet ac motor or induction motor. Fundamental traction and sideways stability of the vehicle is provided by the two large simple wheels which are centrally located side by side. Rest of the tandemly placed holonomic wheels provide horizontal stability to the vehicle, and also provide extra traction by the powered rotation of the individual wheels and steering guidance by the powered rotation of the rollers with electromagnetic elements induced by the stators which are linked to the chassis of the vehicle, when the rollers are in ground contact. A semi-helix magnetic or electromagnetic element in close proximity of the holonomic wheel tire constituted by the electromagnetic rollers, and fixed to the chassis, impart a rotatory force on passing electromagnetic rollers to angularly displace them to avoid their getting into ground contact repeatedly at fixed places on their external cylindrical surfaces, even when the vehicle is following a perfectly rectilinear path.  
         [0013]     Accordingly, a principle object of the present invention is to simplify the construction of small electric motor vehicle.  
         [0014]     It is another object of the invention that the bearing and the electrical drive mechanism are integrated.  
         [0015]     It is a further object of the invention to devise a traction vehicular arrangement with high negotiability and without any mechanical steering whatsoever, to effect remote control driving of the traction vehicular arrangement.  
         [0016]     Another object of the invention is to develop a large-diameter holonomic wheel with powered rollers forming the tire to have active control while steering and to avoid bending forces on the wheel axle generated by the travel of the vehicle on which the holonomic wheel is fixed.  
         [0017]     An additional object of the invention is to devise a large vehicle augmenting the reliability of the concept of two parallel wheels put side by side, forming a vehicle with an addition of holonomic wheels with powered rollers forming the tire.  
         [0018]     The characteristic features of the invention are set forth, in particular, in the appended claims; however, the following description in detail in context to the drawings facilitates a greater understanding of the unique concepts which this invention embodies. But this should be taken as illustrative, rather than restricting the scope of the ideas set forth in the section of claims. The principles and features of this invention may be utilized in applications outwardly dissimilar but in essence not departing from the scope of this invention.  
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0019]      FIG. 1  is a side view of a two-wheel electric motor vehicle in accordance with the first version of present invention where there are just two wheels parallel to each other. The wheels are shown resting on level ground, as well as a plane with 20 degrees incline.  
         [0020]      FIG. 2  is the leading part of an enlarged cross-sectional view taken along line  20 - 20  in  FIG. 1  to show details of the annular wheel of the first version of present invention.  
         [0021]      FIG. 3  is a general plan view of the first version of the present invention where there are just two wheels parallel to each other.  
         [0022]      FIG. 4  is a general front view of the first version of present invention where there are just two wheels parallel to each other.  
         [0023]      FIG. 5  is a general side view of the second version of present invention with two parallel wheels, to function as a traction vehicle.  
         [0024]      FIG. 6  is a general front view of the second version of present invention with two parallel wheels, to function as a traction vehicle.  
         [0025]      FIG. 7  is an enlarged cross-sectional view taken along line  21 - 21  in  FIG. 5 , limited by a “dot-dash” circle drawn around line  21 - 21  and rotated 90 degrees around line  21 - 21  towards the semi-circular arrow encircling the “dot-dash” circle, to show general details of the bearing and driving mechanisms of the hubs of the two parallel wheels in  FIG. 5 .  
         [0026]      FIG. 8  is an enlarged cross-sectional view taken along line  22 - 22  in  FIG. 5 , limited by a “dot-dash” circle drawn around line  22 - 22  and rotated 90 degrees around line  22 - 22  towards the semi-circular arrow encircling the “dot-dash” circle, to show details of mounting of the axles of the two parallel wheels on the chassis in  FIG. 5 .  
         [0027]      FIG. 9  is a schematic side view of the third version of present invention using electromagnetic holonomic wheels in tandem with two parallel wheels.  
         [0028]      FIG. 10  is a schematic plan view of the third version of present invention using electromagnetic holonomic wheels in tandem with two parallel wheels.  
         [0029]      FIG. 11  is an enlarged cross-sectional view taken along line  23 - 23  in  FIG. 10  to show only the details of one roller element with permanent magnets, of the electromagnetic holonomic wheel with a discontinuous toroidal tire.  
         [0030]      FIG. 12  is an enlarged cross-sectional view taken along line  24 - 24  in  FIG. 10  to show the general details of a tire of continuous construction.  
         [0031]      FIG. 13  is an enlarged cross-sectional view taken along line  25 - 25  in  FIG. 10  to show only the details of one roller element with squirrel-cage rotor formation, of the electromagnetic holonomic wheel with a discontinuous toroidal tire.  
         [0032]      FIG. 14  is an enlarged cross-sectional view taken along line  26 - 26  in  FIG. 9  to show the details of the bearing, driving, steering and braking mechanisms of the electromagnetic holonomic wheel with a discontinuous toroidal tire constituted of rollers with squirrel-cage rotor formation.  
         [0033]      FIG. 15  is a plan view of  FIG. 14  to show some details of steering, braking and stator positioning mechanism.  
         [0034]      FIG. 16  is a schematic pictorial partial view of the electromagnetic holonomic wheel of present invention along with two integral radially cut-away views across the rim of the wheel to show details of the axial mount of an individual roller and some cross-sectional details of the inside of one roller element with permanent magnets forming a rotor along with dual stator formation.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     The first version of the present invention is described in detail with the aid of  FIG. 1  through  FIG. 4 . The total height of the vehicle in  FIG. 1  is nearly 1370 mm. In this present form, it is designed to accommodate two persons with some luggage space at the back. The seats are marked  65  in  FIG. 1 ,  FIG. 3  and  FIG. 4 . Batteries  50  in  FIG. 1  are placed below seats  65 . There is a provision to keep eight 100AH 12V lead acid batteries. The total weight of the batteries is approximately 240 kg. The position of batteries  50  keep the center of gravity of the vehicle very low; this, coupled with the eccentric loading on the vehicle, provides stability to the vehicle, in spite of its having only two parallel wheels. The top and front sides of the battery enclosure have to be strong and fully linked with the structure of the shell and, at the extremities, with the direct-drive rim motors: So that, in case of an accidental collision, the batteries  50  do not damage the legs of the occupants of seats  65  ( FIG. 1 ,  FIG. 3  and  FIG. 4 ). The linking of the two ends of the shell with the body elements  66  and battery enclosure elements  67  and  68  ( FIG. 1  and  FIG. 4 ) increases the overall strength of the vehicle shell  64  ( FIG. 1  and  FIG. 4 ).  
         [0036]     Backrest  58  ( FIG. 1 ,  FIG. 3  and  FIG. 4 ) of seats  65  can be adjusted angularly around reclining axis center  49  to obtain different reclining angles. In  FIG. 1 ,  FIG. 3  and  FIG. 4 , the areas marked  52 , on the front and rear both, indicate lightweight plastic bumpers. In case of a collision, to avoid the shock getting transferred on to the wheels and distorting them and to protect the passengers, plastic bumpers  52  and ridged crush-zone elements  53  ( FIG. 1 ,  FIG. 3  and  FIG. 4 ) absorb most of the kinetic energy of the impact by collapsing. The tires are large in diameter (nearly 1575 mm), but are narrow (65 mm). Doors  59  ( FIG. 1 ) on both the sides of the vehicle are hinged underneath point  69  ( FIG. 1 ) to wheel casing  99  ( FIG. 2 ) on surface  101  ( FIG. 2 ). The possible sliding glass portions of the window is marked  51  in  FIG. 1 .  
         [0037]     Windscreens  110  ( FIGS. 3 and 4 ) are glued to vehicle shell  64  ( FIG. 1  and  FIG. 4 ). Headlamps  112  ( FIG. 3  and  FIG. 4 ) are placed just above ridged crush-zone elements  53 . In order to conserve power, use is made of two 20 W fluorescent tubes for headlamps  112  driven by high frequency drivers. The right and left turn indicators are marked  113  in  FIG. 3  and  FIG. 4 . The two fluorescent tubes with suitable cylindrical reflectors produce high and low beams; lenses in the path of light help to further focus the light beam.  
         [0038]     There are two separate switching regulators for each multitude of brush-less dc motors rotatably locating annular wheel drum  75  ( FIG. 2 ) by engaging with two parallel O rings  16  ( FIG. 2 ). Rotor  94  ( FIG. 2 ) is of truncated biconic form. Stator  96  ( FIG. 2 ) is fixed in the toroidally formed channel  85  as shown in  FIG. 2 . Toroidally formed channel  85  is secured to vehicle shell  64  ( FIG. 1  and  FIG. 4 ) with the use of toroidal cushion  86  with pneumatic cavity  88  and steel cords  87  (all in  FIG. 2 ). Toroidal cushion  86  is made of elastomeric material and grips double-flanged member  89  ( FIG. 2 ). Double-flanged member  89  on its internal flanged flat side is bolted ( 90  in  FIG. 2 ) to wheel casing  99 , while, from the outside, wheel protector baffle  62  is mounted on to it with screws  98  ( FIG. 2 ). Wheel protector baffle  62  ( FIG. 1 ,  FIG. 2 ,  FIG. 3  and  FIG. 4 ) is injection molded with a thermoplastic. Elements  60  and  61  ( FIG. 1 ) also are modified wheel protector baffles doubling up as side bumpers. Similarly, element  48  ( FIG. 1 ) is an injection-molded bumper to protect door  59  ( FIG. 1 ). Electrical conductors to each BLDC motor enter stator  96  sideways from slot  93  to travel through coaxial tubular cavity  91  to reach stator windings  83 , via radial holes  92 , after switched by electronics placed in cavity  100 . Multi-pole ring magnet  82  is made of rare earth elements. Each BLDC motor has two numbers of double-Z ball bearings  95  (all in  FIG. 2 ). Annular wheel  57  has a solid rubber tire  56  ( FIG. 1 ,  FIG. 2 ,  FIG. 3  and  FIG. 4 ) secured on rim  73  ( FIG. 2 ). Solid rubber tire  56  has a grooved tread  70 , nylon fiber ply  71  and steel cords  72  ( FIG. 2 ). Annular wheel  57  is held in place with multiple studs  103  and nuts  77  ( FIG. 2 ). Ring  104  secures O-ring stopper  78  and dust protector  79  on the other side of the side annular wheel  57  is fixed on annular wheel drum  75 . By altering the rpm of individual wheels, steering of the vehicle is achieved. Dynamic regenerative braking is also effected by the two switching regulators and is very effective, owing to the large diameter of the annular wheel  57  ( FIG. 1 ). At the parting lines of annular wheel drum  75  and toroidally formed channel  85  ( FIG. 2 ), to protect the bearing and driving mechanisms from dirt, there are thin annular rubber curtains  80  and  81  ( FIG. 2 ), against which there is an optional positive air pressure from the inside of toroidally formed channel  85 —worked up by small centrifugal fan pumps which suck filtered air from the inside of the vehicle and push it out through the leakage between the line of contact between annular rubber curtains  80 ,  81 , and annular wheel drum  75  and toroidally formed channel  85 , to prevent the entry of dust, dirt and water at low pressure heads.  
         [0039]     In the case of the failure of the switching devices of one or both the switching regulators, there is a provision for two parallel stopping drives which otherwise work as regenerative brakes to first charge two capacitors from the regenerated braking power and then to step up the capacitor voltage with a switching converter and then to charge batteries  50  ( FIG. 1 ). To act as parking brakes, there are four small dc motors with integral gears driving four threaded shafts which in turn move threaded sliders lined with braking material. Application of this braking arrangement involves the rotation of the geared dc motors in the positive direction in order to move the sliders towards the internal cylindrical surface of annular wheel drum  75  ( FIG. 2 ) lying between the seats of two O rings  76  ( FIG. 2 ). When the brake linings press against the wheel drum face, due to the enormous diameter of annular wheel drum  75 , the braking effectiveness is good. In order to release this parking brake, the direction of motor rotations is reversed by electrically reversing the connections to the small dc motors. This braking is useful for parking, injecting a dc voltage in the brush-less dc motor windings to achieve electromagnetic braking would drain the batteries, and short-circuiting of BLDC motor windings only effects dynamic braking.  
         [0040]     Steering, speed and braking are manually controlled by operating a wired or cordless manipulator; the driver may sit at any location in the vehicle. Ground clearance even on an incline of 20 degrees is adequately demonstrated with reference to surface  54  in  FIG. 1  in comparison to level ground  55  ( FIG. 1  and  FIG. 4 ).  
         [0041]     By making the driver sit in a more crouched manner, the diameter as well as the breadth of the vehicle could be reduced to produce a small vehicle, unlike the conventional bikes: A stable vehicle suitable for single occupancy, protecting the occupant from the vagaries of the weather.  
         [0042]     The peculiarities of this electric vehicle design make it very stable in dynamic performance. While applying brakes, vehicle shell  64  ( FIG. 1  and  FIG. 4 ) tends to rotate with the wheels, but the heavy battery compartment keeps moving forward, thus canceling the likely swing of vehicle shell  64  anti-clockwise.  
         [0043]     The batteries, even if replaced by fuel cells or superconductor assemblies, always have one common feature—weight. The weight of the electrical energy storage or generating units could not possibly be reduced in near future. In this first version of the present invention, concentration of weight lends itself remarkably well to the effective functioning of this electric motor vehicle.  
         [0044]     Backrest  58  and head rests  63  ( FIG. 1 ,  FIG. 2  and  FIG. 4 ) are padded equally on both front and rear sides, making it possible to sit inside the vehicle facing any of the two ends—conventional front or rear—and drive, as there are no mechanical linkages for driving this vehicle; and the manipulator could be operated from any location. Additionally, with backrest remaining vertical, passengers can occupy the whole of seats  65 , accommodating two more passengers as a result.  
         [0045]     The second version of the present invention is described in detail with the aid of  FIG. 5  through  FIG. 8 . The outer diameter of traction tire  121  ( FIG. 5  and  FIG. 6 ) is nearly 1370 mm. Traction tire  121  is non-pneumatic and is fixed on traction wheel  132  ( FIG. 5  and  FIG. 7 ). Traction wheel  132  is bolted to traction wheel drum  141  ( FIG. 7 ) in manner described hereinbefore and shown in  FIG. 7 . The bearing and driving mechanisms are common, and are shown in  FIG. 7 . It is essentially the same as described earlier and shown in detail in  FIG. 2 . There are only three modifications: (a) two numbers of BLDC motors are axially adjacent at one circumferential location, (b) toroidally formed channel  85  of  FIG. 2  is replaced by floating ring  131  and axle ring  139  ( FIG. 7 ); and (c) dust protector  79  in  FIG. 2  is modified (element  140  in  FIG. 7  and  FIG. 8 )) to radially extend near axle locator  127  ( FIG. 6  and  FIG. 8 ) at the center of traction wheel  132 . Element  140  seals the internals of wheel bearing and driving mechanisms in conjunction with O rings  129  and  137  ( FIG. 8 ). Four numbers of clamping bolts  138  ( FIG. 8 ) secure axle locator  127  ( FIG. 6  and  FIG. 8 ) to chassis  143  ( FIG. 5 ,  FIG. 6  and  FIG. 8 ). Dust protector baffle  142  ( FIG. 7  and  FIG. 8 ) is structurally similar to element  140  ( FIG. 7  and  FIG. 8 ) on its circumference and clamped underneath traction wheel  132  ( FIG. 7 ) to traction wheel drum  141  ( FIG. 7 ); dust protector baffle  142  remains centrally at a distance from axle locator  127  ( FIG. 8 ). Semi-circular profiled O ring  130  is located in a groove medially on the inner annular surface of traction wheel drum  141  ( FIG. 7 ). Semi-circular profiled O ring  130  ( FIG. 7 ) functions as two numbers of O rings  76  ( FIG. 2 ) as shown in  FIG. 7 . External wheel casing  125  ( FIG. 5 ,  FIG. 6  and  FIG. 7 ) is immovably joined to chassis  143  ( FIG. 6  and  FIG. 8 ).  
         [0046]     Batteries  50  ( FIG. 5 ) are similar to the ones employed in the first version of the present invention. Batteries  50  are eight in number and are arranged in a single row on the base of chassis  143  ( FIG. 5  and  FIG. 6 ). The row of batteries  50  is protected by protective bumpers  122  ( FIG. 5  and  FIG. 6 ), which are made of metal or thermoplastic. The front and rear of the vehicle are identical in appearance. Both front and rear of the vehicle have a hook  120  with a locking link  123  held by a pin  124  (all in  FIG. 5  and  FIG. 6 ). Driver seat  133  ( FIG. 5  and  FIG. 6 ) is optional, as the vehicle can be driven by remote or programmed to follow fixed paths. In the absence of driver seat  133  the space above batteries  50  ( FIG. 5 ) can be used for carrying goods. Positioning channels  134  ( FIG. 5  and  FIG. 6 ) serve to lift and lower driver seat  133  which gets located from rocking axis ends  135  ( FIG. 5  and  FIG. 6 ). Rocking axis ends  135  also locate driver seat  133  when it is tilted suitably to interchange the backrest with sitting space, to make the driver sit facing the other end of the vehicle. Lowering of driver seat  133  enables the vehicle to travel as a vehicle which is functionally similar to the first version of the present invention.  
         [0047]     The third version of the present invention is detailed with the aid of  FIG. 9  through  FIG. 16 . In  FIG. 9 , a vehicle is resting on level ground  55 . Vehicle chassis  154  has six numbers of wheels of different diameters. Four of the wheels on the left side in  FIG. 9  and  FIG. 10  have their axes marked  151 ,  152 ,  153  and  153 . Simple wheels  157  in  FIG. 9  and  FIG. 10  seem to have a common axis  153  which perpendicularly bisects longitudinal mesial line  150  in  FIG. 10 . Longitudinal mesial line  150  ( FIG. 10 ) is an imaginary line drawn in  FIG. 10  to indicate the locations of simple wheels  157  and electromagnetic holonomic wheels  155  ( FIG. 9  and  FIG. 10 ). If the length of this vehicle is extended by adding more wheels on both sides of axis  153  as marked in  FIG. 10 , the additional wheels have to be electromagnetic holonomic wheels  155 . Electromagnetic stator unit  201  ( FIG. 9 ,  FIG. 10 ,  FIG. 14 ,  FIG. 15  and  FIG. 16 ) generates a moving electromagnetic field which magnetically forces the rollers on electromagnetic holonomic wheel  155  to rotate or stall, depending upon the direction or nature of the electromagnetic field generated by electromagnetic stator unit  201 .  
         [0048]     The vehicle as depicted in  FIG. 9  and  FIG. 10  utilizes two parallel simple wheels  157  for main traction, steering, braking and sideways stability while traveling. Basic operation of two parallel simple wheels  157  ( FIG. 9  and  FIG. 10 ) is similar to the description of the operation of the first and second version of the present invention hereinbefore; however, the bearing and driving mechanisms can be different. Continuous construction of the solid tire of simple wheel  157  in  FIG. 9  and  FIG. 10  is shown in  FIG. 12  in detail. Grooves  167  on tread  179  ensure road contact in wet conditions ( FIG. 12 ) and ply  165  forms the skeleton of the tire ( FIG. 12 ). Wheel  163  ( FIG. 11 ,  FIG. 12 ,  FIG. 14  and  FIG. 16 ) is of general construction. Rim  73  in  FIG. 12  is generally similar to as detailed in  FIG. 2 . The base width and shape of rim  73  in  FIG. 12  depends upon the thickness and construction of tire selected for simple wheels  157  ( FIG. 9  and  FIG. 10 ).  
         [0049]     The rollers on electromagnetic holonomic wheel of the present invention are internally of two possible types (a) magnetic and (b) electromagnetic.  FIG. 11  shows the details of a multi-pole magnetic roller. Permanent magnet pole pieces  156  ( FIG. 11 ) are fixed uniformly on the outer cylindrical side of an Archimedean spiral composed of a spring steel strip  177  ( FIG. 11 ), which starts and ends shaped as small and large concentric right circular cylinders. The magnetic poles of permanent magnet pole pieces  156  ( FIG. 11 ) alternate in direction with their alternate poles radially directed outwards. The Archimedean spiral composed of spring steel strip  177  ( FIG. 11 ) has a variable lead which increases in the middle of the curve and becomes zero at the point of termination (shown in  FIG. 11  and  FIG. 16 ). The Archimedean spiral composed of spring steel strip, with permanent magnet pole pieces  156  fixed as described, is molded with an elastomeric medium  158  ( FIG. 11 ); this whole unit in turn is fixed on a nylon bushing  159 , and a rubber tread ring  178  ( FIG. 10  and  FIG. 11 ) cylindrically covers the external surface of this whole unit to form a magnetic roller ready to come into contact with level ground  55  ( FIG. 9 ) after axle pin  160  ( FIG. 11  and  FIG. 16 ) is passed through nylon bushing  159  ( FIG. 11 ) and axle pin  160  is fixed from both ends to brackets  175  ( FIG. 11 ). Dual brackets  175  ( FIG. 11  and  FIG. 16 ) are equal in number to the number of magnetic rollers on electromagnetic holonomic wheel  155  ( FIG. 10 ). Brackets  175  ( FIG. 11 ) are uniformly joined to rim  162  ( FIG. 11 ,  FIG. 13 ,  FIG. 14  and  FIG. 16 ) to rotatably hold all the magnetic rollers from their axle pins  160  ( FIG. 11  and  FIG. 16 ). Axle pins  160  have sealing grooves which position sealing rings  161  ( FIG. 11 ), in order to prevent foreign material from getting into the bearing formed by axle pin  160  and nylon bushing  159  (shown in  FIG. 11 ). Every electromagnetic holonomic wheel of the present invention that employs axle pins  160  to rotatably hold electromagnetic rollers of either kind has to have one axle pin  160  of slightly modified construction, in which it has a threaded joint in the middle lengthwise. This joint makes the modified axle pin manually adjustable in length. This helps in the final fixing of all axle pins  160  ( FIG. 11  and  FIG. 16 ) together with the rollers on rim  162  ( FIG. 11  and  FIG. 16 ).  
         [0050]     Electromagnetic rollers on electromagnetic holonornic wheel of the present invention are best described with the aid of  FIG. 13  and  FIG. 14 . In  FIG. 13 , silicon steel stampings form squirrel cage-rotor stack on the cylindrical exterior of which are fixed aluminum squirrel-cage conductors  170  in angular uniformity. Fiber ply  174  ( FIG. 13  and  FIG. 14 ) is spirally interspersed in elastomeric medium  158  ( FIG. 11 ,  FIG. 13 ,  FIG. 14  and  FIG. 16 ). Elastomeric medium  158  cylindrically holds on the outside the assembly of squirrel-cage rotor stack  171  and aluminum squirrel-cage conductors  170 , and internally grips nylon bushing  159  which is rotatably positioned by axle ring  172  (all best viewed in  FIG. 13 ). Rubber tread ring ( FIG. 13  and  FIG. 11 , as well as in  FIG. 14  and  FIG. 16 ) fits on the external cylindrical surface of squirrel-cage rotor stack  171 . Spacer brackets  176  ( FIG. 13  and  FIG. 14 ) are similar to brackets  175  ( FIG. 11  and  FIG. 16 ), except for the fact that spacer brackets  176  are shorter in height compared to brackets  175  with the top half of the hole in brackets open to receive axle ring  172  which is almost full circle with just a missing part; this missing part is a small lock nut (not shown) which holds both ends of axle ring  172  together. The roller meant to be positioned after tightening of lock nut is made of two identical halves (not shown) that are screwed on to each other after positioned appropriately around axle ring  172  ( FIG. 13 ). In  FIG. 13  two circular grooves (not shown) can be cut on either ends in the bore of nylon bushing  159  to accommodate two rubber seals accomplishing the function of sealing rings  161  ( FIG. 11 ).  
         [0051]     Electromagnetic stator units  201  ( FIG. 9 ,  FIG. 10 ,  FIG. 14 ,  FIG. 15  and  FIG. 16 ) are essential for effective operation of the holonomic wheel of the present invention. The placement and orientation of electromagnetic stator unit  201  is shown in  FIG. 16 , while one possible version of the placement of electromagnetic stator unit  201  is shown in  FIG. 14 . and  FIG. 15 . Stator windings  200  ( FIG. 14  and  FIG. 16 ) are basically similar, in spite their being wound for different kind of electric motors; it is an induction motor in  FIG. 14 , while in  FIG. 16  it is a permanent magnet ac motor. For having a higher number of poles with higher torque generation ability it is necessary that the magnetic circuit between the left-hand side and right-hand side stator units  201  is joined using ferromagnetic members outside of the rotor elements positioned inside the rollers of the electromagnetic holonomic wheel of the present invention. This joining is done at semi-circular lock  211  ( FIG. 14 ) involving silicon steel stampings stacked together forming stator link  218  ( FIG. 14 ) and two numbers of electromagnetic stator units on either side of holonomic wheel drum  202  ( FIG. 14 ). Semi-circular lock  211  ( FIG. 14 ) allows a little angular freedom with reference to the geometrical center of concentric semi-circles of semi-circular lock  211 . This angular freedom is essential for top cam disc  207  ( FIG. 14  and  FIG. 15 ) and bottom cam disc  208  ( FIG. 14 ) to rotate appropriately urged by planetary gears  212  ( FIG. 15 ) driven by geared dc motor  206  ( FIG. 14 ) through pinion  216  ( FIG. 15 ). Top cam disc  207  and bottom cam disc  208  to the naked eye look like perfectly circular discs; their diametrical deviations at different points of their circumference is less than a millimeter. They are assembled with reference to each other; and by their joint predetermined amount of rotation governed by an encoder built into geared dc motor  206  ( FIG. 14 ) the physical proximity of both electromagnetic stator units  201  to rubber tread rings  178  ( FIG. 14  and  FIG. 16 ) is controlled in order to effect electromagnetic and mechanical braking of the electromagnetic rollers and electromagnetic holonomic wheel  155 , and also to optimize the magnetizing current through stator windings  200  ( FIG. 14  and  FIG. 16 ): In rough driving conditions the physical proximity is decreased to avoid any possible mechanical friction between electromagnetic stator units  201  and rubber tread rings  178 ; conversely, on smooth roads the physical proximity has to increase in order to increase control over electromagnetic rollers to avoid veering off of the vehicle of the present invention due to insufficient surface friction and steering control. Wheel  163  ( FIG. 14 ) is of general construction and described with reference to  FIG. 2  and  FIG. 7  hereinbefore. Holonomic wheel drum  202  ( FIG. 14 ) is made of aluminum alloy to keep it light in weight. Bolts  203  locate wheel  163  ( FIG. 14 ). Two each of O rings  204  and  205  are respectively similar to O rings  130  ( FIG. 7 ) and  76  ( FIG. 2 ) except for dimensional variations. Bearing and driving mechanisms are also similar to the ones shown in  FIG. 2  and  FIG. 7 , except for increase in the number BLDC motors in the axial row by one. Toroidally formed channel  209  ( FIG. 14 ) is also similar to toroidally formed channel  85  ( FIG. 2 ) except for an extra axial inverted V-shaped cavity to accommodate the extra BLDC motor just described. Insulating spacer  210  ( FIG. 14 ) is employed to stop wasteful eddy current generation into toroidally formed channel  209  ( FIG. 14 ). Cover plate  214  ( FIG. 14 ) is screwed on with screws  215  ( FIG. 14  and  FIG. 15 ) to vehicle chassis  154  ( FIG. 9 ,  FIG. 10  and  FIG. 14 ) on the opening above top cam disc  207  ( FIG. 14  and  FIG. 15 ).  
         [0052]     In  FIG. 16  twisted magnetic strip  230  is connected to vehicle chassis  154  ( FIG. 9  and  FIG. 10 ) and has both magnetic poles  231  and  232  ( FIG. 16 ) all through uniformly facing rubber tread rings  178  ( FIG. 16 ) on all the magnetic rollers in  FIG. 16 . As wheel  163  ( FIG. 16 ) rotates around wheel axis, adjacent magnetic rollers line up in an orderly manner as opposing magnetic poles located in adjacent magnetic rollers pull close. When no steering taking place and the vehicle traveling in a straight line on level ground  55  ( FIG. 9  and  FIG. 10 ), the magnetic rollers in  FIG. 16  do not rotate around their respective axis (two such axes are shown as axle pins  160  in  FIG. 16 ); in this condition the magnetic field produced by twisted magnetic strip  230  ( FIG. 16 ) imparts a rotating magnetic field on permanent magnetic pole pieces  156  ( FIG. 11  and  FIG. 16 ), which urges the magnetic rollers to displace angularly around their respective axes, axle pins  160 . The electromagnetic rollers depicted in  FIG. 13  and  FIG. 14  will also displace in the same manner when subject to the rotating magnetic field just described.  
         [0053]     Magnetic or electromagnetic sensors are fixed in line but at a distance from the symmetrical ends (one of the ends showing stator windings  200  in  FIG. 14  and  FIG. 16 ) of electromagnetic stator units  201  ( FIG. 14  and  FIG. 16 ). The sensors pick up signals from rotating rollers after they leave ground contact with the rotation of wheel  163  ( FIG. 14  and  FIG. 16 ) as the vehicle travels on level ground  55  ( FIG. 14 ). These signals are useful in efficient steering control. In many traveling conditions, active rotation of the rollers by powering electromagnetic stator units  201  is not needed; just by differential rotation of two simple wheels  157  ( FIG. 9  and  FIG. 10 ) adequate steering is achieved. In those conditions signals from the sensors just described are sampled and if found adequate, no power is supplied to electromagnetic stator units  201 . The sensors also sense insufficient rotation of the rollers and for a short duration the power to electromagnetic stator units  201  is increased.  
         [0054]     An increase in the number of electromagnetic stator units  201  ( FIG. 14  and  FIG. 16 ) symmetrically on both sides of wheel  163  ( FIG. 14  and  FIG. 16 ) replicating the arrangement of electromagnetic stator units  201  in  FIG. 16  in a circular row not only increases steering power to some extent; but it also helps in urging the main rotation of wheel  163  ( FIG. 14  and  FIG. 16 ) around its main axis, as different row-wise placed electromagnetic stator units  201  are sequentially powered, producing a circulating magnetic field in sympathy with the main rotation of wheel  163  ( FIG. 14  and  FIG. 16 ). Extra electromagnetic braking force is also developed using this arrangement.  
         [0055]     Extra magnetic or electromagnetic sensors are fixed to vehicle chassis  154  ( FIG. 9 ,  FIG. 10  and  FIG. 14 ), close to the rollers of electromagnetic holonomic wheel of the present invention. These sensors pick up signal corresponding to the main rotation of wheel  163  as well as the rotation of rollers on wheel  163  ( FIG. 9 ,  FIG. 10 ,  FIG. 14  and  FIG. 16 ). These sensors are of importance because they confirm the main rotation of wheel  163  in addition to the sensors described earlier, and they also sense the necessary constant angular displacement of the rollers on wheel  163  under the magnetic influence of twisted magnetic strip  230  ( FIG. 16 ) and/or electromagnetic stator units  201  ( FIG. 14  and  FIG. 16 ).  
         [0056]     The rollers in  FIG. 11  can be made lighter by using multi-pole plastic-magnet rings instead of permanent magnet pole pieces  156 . Only rubber tread rings need be replaced after wear. The rollers in  FIG. 13  can be designed to function without rubber tread rings  178 . For this purpose, aluminum squirrel-cage conductors  170  have to be of hardened aluminum alloy, and squirrel-cage rotor stack  171  has to be made of hard silicon-steel stampings ( FIG. 13  and  FIG. 14 ). Special purpose vehicles can be made using such rollers.

Technology Classification (CPC): 1