Abstract:
A method of propelling a transit vehicle steered by a centerline electrified structural guidebeam located between two special steel load-bearing rollway beams, using magnetic linear motors suspended between each pair of steerable load-bearing wheels, to react inductively on the rollway beams, to produce tractive effort by four linear motors mounted under an eight wheel car.

Description:
TECHNICAL FIELD 
     This invention relates in general to public transportation vehicles and more particularly to electric commuter cars and regional rapid transit cars. 
     BACKGROUND OF THE INVENTION 
     The majority of the electrically powered transit systems of the world use conventional rotating electric motors to provide the motive force to propel the train. The basic method used to transmit the shaft work of the electric motor to the axle-mounted driving wheels of the massive swiveling bogies is a heavy encased set of lubricated reduction gears riding on the axles. 
     In modern inter-city and regional commuter passenger coaches, a Diesel engine is attached to a transmission housing containing a hydraulic torque amplifier, a set of reversible reduction gears, and a hydraulic retarder. This combination drives the wheels through axle mounted final reduction gears. Both of these drive systems are heavy, costly, and require expensive maintenance and downtime procedures. The diesel exhaust gases contribute to atmospheric and surface contamination. 
     Thus there is a need for a new and more efficient means of propelling a light-weight vehicle on a high-strength elevated structural rollway above all surface obstacles. 
     Further, there is a need for motors that have no drive-line gears, no heavy final reduction gears, and are not axle-mounted in massive swiveling bogies. 
     Lastly, there is a need for multiple pairs of motors that have an associated computer system that integrates all variable operating conditions required for the most efficient energy consumption consistent with good passenger service and vehicle performance. 
     None of the known prior art disclose such linear motors and computer combination as set forth herein. The present invention as delineated meets these needs. 
     This invention with its many innovations provides an improved transportation vehicle that uses two magnetic linear motors at each end of the rigid vehicle which inductively react with the special steel rollway surfaces to develop the propulsion force. 
     This invention provides a major design modification to existing conventional passenger vehicle understructure propulsion equipment, to reduce cost, weight, and increase productivity. 
     SUMMARY OF THE INVENTION 
     It is an object of this invention to form a simple design having a three-phase magnetic linear motor suspended by, and between pairs of individually load-supporting, non propulsive, resiliently cushioned, central guide-beam steered wheels. 
     It is a further object of this invention to form a comprehensive design, having many computer controlled means of electrically responding to digitally integrated programs, track-side signals, and central dispatcher modifications. 
     It is also a further object of this invention, to provide a vehicle that is quiet, has a smooth rapid acceleration, needs less maintenance, and requires a reduced total investment of travel infrastructures and land acquisition costs. 
     The concept of this design is to create a public transportation vehicle that has no revolving mechanical power devises used in propelling the vehicle along its rollway. A single electromagnetic linear motor is rigidly suspended between each steerable pair of load-bearing wheels that roll on the flat surfaces of a steel structural guideway. The linear motor assembly is secured in a carrier frame bolted to locating arms extending from the axle arms over the inter-axle support beam, with adjustable means to maintain a specific “air-gap” clearance between the motor and the rollway surface. 
     Forced air is ducted to many small channels created in the insulated coil-windings and laminations of the linear motor to cool it and exclude dirt and debris. The linear motors provide an accelerating and retarding function that is greater than that of existing power wheel adhesions, because they are completely independent of weather conditions such as rain, glaze-ice and snow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention may be more readily described by reference to the accompanying drawing in which: 
     FIG. 1 is an elevation of a typical passenger transit vehicle showing the locations of each pair of magnetic linear motors at each end of the vehicle; 
     FIG. 2 shows a 4-wheel end group with a linear unit suspended between a pair of steerable load bearing wheels riding on an electromagnetic steel roll-way; 
     FIG. 3 shows a below-the-floor plan view of one half of a four-wheel group assembly of the structural apparatus required to harness a linear motor to the radial axle arms of the pivotal wheel-hub bearing supports. (wheels removed); and 
     FIG. 4 shows a horizontal view of the method of adjustably supporting the linear motor to the radial axial arms of the load bearing wheels. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, depicts a transit vehicle  6  having a passenger load containing body  7  secured to an underframe structure  8  with a quadruplex  9  having two pairs of load-bearing group-steered wheels  11  supporting each end of transit vehicle  6  for travel along a steel rollway  12 . Transit vehicle  6  is positively guided by a rigid laser-aligned structural steel guide-beam  13  centered between a pair of widely spaced, laser-leveled special steel structural rollway beams  12 . A linear motor  21  is located between each pair of wheels  11  and provides a tractive and reactive magnetic force on rollway  12  thereby propelling transit vehicle  6 . 
     As best seen in FIG. 2, a lower end of transit vehicle  6  shows magnetic linear motor  21  suspended between each pair of wheels  11  by two arms  26  having two horizontal thrust transmitting collared electrical jack-screws  28  mounted on an inter-axle support beam  23  (not shown) for precise maintenance of the magnetic air-gap spacing (7 to 10 mm.) between linear motor  21  and structural special steel rollway beams  12 . 
     Cooling and purge air is flexibly ducted to linear motor  21  encasement from a positive displacement blowers  33  receiving air from an intake cleaner and drier  34 . 
     Best seen in FIGS. 3 and 4 is quadruplex  9  which guides, supports and propels the transit vehicle  6 . In FIG. 3, wheels  11  have been removed to clearly show quadruplex  9  support for linear motor  21  from radial axle arms  26 . 
     As shown, pivotal wheel bearing hubs  14  are steered by lateral rods  15  from a bell-crank lever  16  centered between axle arm anchoring pivots  27  secured to the underside of structural frame  8  (not shown in FIG.  3 ). Each bell-crank  16  is connected by a side rod  17  to a power-steering arm  18  actuated by a demountable guide follower  20  having two pairs of side wheels  19  that side-ride center guide-beam  13 . This mechanism is completely set forth in U.S. Pat. No. 6,129,028 which issued Oct. 10, 2000 to the present inventor. 
     Magnetic linear motor  21  is supported by two locating arms  22  that have four spring loaded lateral leveling motor mounting screws  22   b . Locating arms  22  are pivoted from a hub  26   a  extended below the axle arms  26 . The weight and thrust of linear motor  21  is transferred to an inter-axle support beam  23  by means of two computer adjustable collared jack-screws  24  that maintain the desired magnetic air-gap clearance. 
     Two sets of diagonal rods  29  connect axle arms  26  to a central anchorage pivot  36  on underframe structure  8  and thereby transfer thrust forces induced by linear motor  21  to underframe structure  8  as it accelerates transit vehicle  6 . 
     A proportion of the weight of transit vehicle  6  vertically imposed on each axle arm  26  is transmitted directly down from underframe structure  8  by a pair of hydro-pneumatic shock absorbing-leveling cylinders  40 . Hydraulic and parking brakes are conventional, but not delineated in this invention specifics of design. 
     Continuous roll-way  12  is made of a special alloy steel with enhanced electromagnetic qualities and has spaced cross-beams  12   c  and adjustable mountings  12   x  for laser lateral alignment of the guide-beam  13 . A support bracket  13   s  is welded to two guide-beam channel bars  13   b  and that contain two insulator supported “third-rail” conductor bars  13   c.    
     Linear motor  21  is supported by locating arms  22  which are pivoted from axle-arms  26  and extend over inter-axle support beam  23 . Collared electric jack-screws  24  thrusting down on the support beam  23  maintain the magnetic “air-gap” clearance of linear motor  21  above the surface of the rollway  12 . 
     One quarter of the total weight of the end of transit vehicle  6  is carried on the dual hydro-pneumatic shock-cushion leveling cylinders  40  which are mounted under the wheel pivot yoke of axial arm  26  and up to underframe structure  8 . A computer (not shown) reads a series of level indicators to vary the fluid levels therein to accurately align the car floor with the station platforms. 
     A cooling air duct  31  having a vertical expansion bellow-ring  32  extend below positive displacement blowers  33  to linear motor  21 . Air from intake cleaner and drier  34  is rain screened, filtered and dried before entering blowers  33 . The windings, insulation and laminations of linear motors  21  are encapsulated with moisture-proof plastic. For maximum protection, a exterior coil windings  21   x  of linear motor  21  are encased with rigid kevlar jackets. 
     Quick motor dismounts  22   b  are in combination with well-known drop-pit apparatus facilitates service repair or replacement of linear motor  21 . 
     Several advantages of the present invention are apparent: Total weight is reduced by the elimination of massive bogies with heavy axle mounted traction motors geared to drive heavy steel wheel sets. Acceleration and dynamic braking efforts require no friction contact to rollway  12 . Linear motors  21  provide greater rates of acceleration than slipping drive-wheels, and better rates of acceleration and deceleration increase average speed between stations. Riding quality is improved because the unsprung weight is a greatly reduced percent amount of the total weight. The hydro-pneumatic cushion cylinders provide a softer ride. The wide-body vehicle rides on non-steel, non-pneumatic quiet polyurethane treaded wheels  11  rolling on laser-leveled steel surface rollway  12  preferably spaced at 2.5 meters (8 ft-3 in.) for great lateral stability on turns at high speeds. 
     Although but one embodiment of the invention has been shown and described, it will be obvious to those skilled in the art, that various changes and modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.