Transportation system using magnetic belt propulsion

A magnet-type transportation system of a car-side primary type includes a rail of a magnetic material, fixedly laid down along a traveling track, and a power car capable of self-movement by a plurality of wheels adapted to roll over the traveling track. The power car includes a plurality of magnet belt conveyor units, each having a magnet belt extended in an endless manner around a driving wheel and a driven wheel. The power car also includes a power unit and a power transfer/transmission mechanism for driving each conveyor unit. The power car is adapted so that the magnet belts mounted thereon are magnetically attracted to the rail.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a transportation system of a car-side 
primary magnet type including a rail of a magnetic metal material laid so 
as to extend along a traveling track, a power car equipped with driving 
magnet units adapted to be magnetically attracted to the rail for 
circulating movement and a trailing car or trailing cars coupled to the 
power car as occasion demands and capable of carrying passengers therein. 
2. Description of the Prior Art 
A conventional magnet-type transportation system of the so-called CTM 
(continuous transit system by magnet) type employs a method of fixedly 
arranging the driving magnet units on the ground side, that is, the method 
in which the ground side serves as the primary side. More specifically, in 
this case, a plurality of magnetic belt conveyor units, each having its 
own circulating speed and connected to a power source, such as an 
induction motor, and a power transfer mechanism, such as a reduction gear, 
are arranged at given intervals on the ground side in such a manner that 
the magnetic belt conveyor units are laterally or vertically arranged at 
given intervals in a broken-line configuration along the traveling track 
in curved and grade sections. The resulting ground-side magnetic belt 
conveyor line is provided with a speed pattern, including given 
acceleration/deceleration sections and constant speed sections by virtue 
of the preset circulating speeds of the magnetic belt conveyor units. A 
car, having an independently moving function including magnet means 
(electromagnets and/or permanent magnets) adapted to be magnetically 
attracted to the magnetic belts of the conveyor line through support 
means, guide wheels and supporting wheels, or a train composed of such 
cars, is arranged and runs along the line. Such a magnet-type 
transportation system is well known from, for example U.S. Pat. Nos. 
4,197,934, No. 4,278,164, No. 4,289,227, etc. Also, the system has been 
put in practical use as "MITSUKOSHI PANORAMA LINER" at the EXPO'90 
"International Exposition of Flowers and Green Leaves" held in Apr. 1990 
in the city of Osaka, Japan. 
The conventional magnet-type transportation system is so designed that the 
car is hauled for movement by the rolling of the supporting wheels over 
the traveling track surface due to the magnets on the car side being 
magnetically attracted to the magnetic belt conveyors. In this case, the 
rotating shafts of the magnetic belt conveyor units are used in their 
horizontal or vertical positions. In the curved sections the car is 
forcibly guided along the guide tracks which are separately laid down, in 
addition to the ordinary traveling track. 
Also, in the case of a continuous moving path (moving side-walk) disclosed, 
for example, in Japanese Patent Application No. 13911/1988, the magnetic 
belts of ground-side magnetic belt conveyor units are composed of belts 
with magnets. Also, the previously mentioned cars are replaced with a 
plurality of footboard pedestals, which are individually provided with 
magnetic pieces adapted to be magnetically attracted to the magnet belts 
and connected with one another by elastic coupling mechanisms of 
relatively low flexibility. These pedestals are arranged so as to be 
movable over the traveling path by means of the supporting wheels. 
The conventional magnet-type transportation system presupposes a mass 
transportation of the type in which the cars or pedestals successively 
arrive at equal intervals of time at the platform so that the plurality of 
magnetic belt conveyor units, having individually preset speeds, are 
arranged along the traveling track irrespective of the variations and 
volume of the traffic demand and the line, on the whole, is provided with 
the necessary acceleration and deceleration pattern and constant speed 
pattern. In this case, it is necessary to arrange so that even if the 
circulating movement of the magnetic belt conveyor units, constituting the 
ground-side driving source, stops or the electromagnets on the car or the 
like are deenergized, due to such an inconvenience as the interruption of 
service in any part, the cars or the pedestals are restarted at the point 
of fault upon the resumption of normal service. For this purpose, the 
magnetic belt conveyor line must be composed of the magnetic belt conveyor 
units arranged at given intervals as the primary means on the ground so 
that of the plurality of magnets (of the hybrid type using both 
electromagnets and permanent magnets) on +the car side, the required 
number of the magnets are always attracted to any of these magnetic belt 
conveyor units. 
As a result, it can be said that up to the time when the actual traffic 
demand attains the mass transportation demand predicted at the time of the 
building, the number of the magnetic belt conveyor units is considered to 
be excessive, in view of the actual traffic demand, but are arranged on 
the magnetic belt conveyor line. Also, to circularly move the magnetic 
belt conveyor units on the whole line regularly causes excessive energy 
consumption and excessive noise, thus requiring considerable contrivances. 
Also, essentially, the magnetic belt conveyor units must be arranged in 
the central portion of the traveling track and, therefore, the traveling 
track requires a space for the arrangement of the conveyor units as well 
as the attendant motors, rotation transmission mechanisms, etc. Therefore, 
particularly in the case of an elevated type of track, the girders forming 
the traveling track must be of the open structure to ensure the required 
space. An attempt to ensure a sufficient strength against the load 
inevitably limits available space, thereby placing a limitation to the 
construction of the magnetic belt conveyor system which can be arranged 
within the available space. 
The conventional magnet-type transportation system is disadvantageous in 
that the preset car traveling speed pattern is not variable and, 
therefore, any change of the traveling pattern, e.g., an increase or 
decrease of the platforms, a change in the traveling track design, a 
change in the length of the train or the like requires a change in the 
combination of the existing magnetic belt conveyor units or their 
replacement. 
Also, while all the magnetic belt conveyor units on the line can be kept 
circulating regularly, in order to ensure the desired energy saving and 
reduce the occurrence of noise due to the circulating movement, it is 
necessary to add a system so that as for example, only the magnetic belt 
conveyor units in the "feeder section", where the car exits, and the 
adjacent "feeder section" in front thereof in the direction of travel, are 
circulated; this is shifted along with the traveling of the car. 
Since the magnetic belt conveyor units are arranged in a broken-line 
configuration in each of the grade and curved sections, when the car is 
forcibly guided along the curve by its guide wheels, the magnets on the 
car side do not follow the broken line but are obliquely moved relative to 
the magnetic belt surfaces under the effect of a torsional force, 
corresponding to the angle of the broken line, so that depending on the 
circumstances, the magnets are returned to the original positions only 
when the magnetic belts get off in the width direction and get rid of the 
torsional force in the gap portion between them and the preceding magnetic 
belts. In this case, the guide wheels also forcibly guide the car along 
the curved traveling track and are, therefore, subjected to a torsional 
force. Thus, a contrivance is required for alleviating and eliminating the 
occurrence of fatigue rupture due to the repetition of these actions. 
With the conventional magnet-type transportation system, when the car 
passes over adjoining magnetic belt conveyor units, which are different 
stepwise in circulating speed from each other, or during the acceleration 
or deceleration period, the car is accelerated or decelerated to the 
preset speed of the destination magnetic belt conveyor units with an 
attendant slip between the attracted surfaces of the car magnets and the 
magnetic belts of the magnetic belt conveyor units. In this case, an 
irregular speed oscillation phenomenon, tending to deteriorate the riding 
comfort is caused in the car. Therefore, is necessary to devise a counter 
measure such as the one disclosed in Japanese Patent Publication No. 
23270/1983 in which the arranging interval between the magnetic belt 
conveyor units is preset in correlation with the spacing between the 
foremost magnet and the rearmost magnet of the car in such a manner that 
the rearward magnets of the car are separated from the magnetic belt 
conveyor units to which the magnets were previously attracted as soon as 
the forward magnets in the travel direction of the car completely pass 
over to the preceding adjoining magnetic belt conveyor units. This counter 
measure gives rise to an inconvenience of limiting the allowance for the 
designing of the line. 
Also, in the conventional magnet-type transportation system, the divergence 
and convergence of the line are effected in a manner such as that 
disclosed, for example, in the previously mentioned three U.S. Pat. Nos. 
In other words, a pair of electromagnets, each having pole faces turned 
toward the right and left sides respectively, are mounted on the car side 
and magnetic belt conveyor units, having vertical rotary shafts, are 
arranged on the right and left side walls of a ground traveling track so 
as to correspond to the pole faces. Only one or the other of the pair of 
electromagnets is energized and selectively attracted to the magnetic belt 
surface of the corresponding magnetic belt conveyor units, thereby causing 
the car to proceed in the direction of one branching side. The 
energization of the other electromagnet similarly causes the car to 
proceed in the direction of the other branching side. In this case, 
however, at least the pair of electromagnets having the pole faces turned 
toward the right and left sides must be arranged on the car side and their 
energization and deenergization must be controlled for the selection of 
the desired branching direction, thus making it impossible to use 
permanent magnets. In addition, the pair of vertical-type magnetic belt 
conveyor units respectively facing the right and left sides must be 
arranged on the side walls of the traveling track at each of the divergent 
and convergent portions and, moreover, the broken-line arrangement is 
required between the adjoining magnetic belt conveyor units at each of the 
divergent and convergent portions, thus causing the occurence of a 
torsional force corresponding to the broken-line angle in the car magnets 
in the same manner as mentioned previously. 
SUMMARY OF THE INVENTION 
It is the primary object of the present invention to provide a new and 
novel magnet-type transportation system in which the car side serves as 
the primary side and the ground side serves as the secondary side, thereby 
overcoming the foregoing deficiencies in the prior art. 
It is another object of the present invention to provide a magnet-type 
transportation system so designed that only a fixed rail is laid down on 
the ground side so as to make the maintenance and safety control of the 
ground equipment easy and concentrate power equipment on the car to make 
it possible to perform the maintenance and repair of the power equipment 
in a factory, thereby making it possible to accommodate variations in the 
volume of traffic demand by varying the number of cars operated, the train 
make-up and the train operation interval. Such a system also eliminates 
danger of the ground equipment becoming a source Of noise and reduces the 
required energy to the minimum requirement. 
In accordance with one aspect of the present invention there is provided a 
manget-type transportation system of the car-side primary type including, 
as concrete means for overcoming the foregoing deficiencies, a rail made 
of a magnetic material, fixedly arranged along a traveling track, and a 
power car capable of self-movement by its wheels which roll over the 
traveling track. The power car is equipped with a plurality of magnet belt 
conveyor units, each having a magnet belt extended around a driving wheel 
and a driven wheel in an endless manner, a power unit and a power 
transfer/transmission mechanism for driving each belt conveyor unit. The 
magnet belts are adapted to be magnetically attracted to the rail. 
In accordance with still another aspect of the present invention, the 
plurality of magnet belt conveyor units are arranged in pairs, each 
including the-magnet belt conveyor units arranged on both sides of the 
rail so as to oppose each other through the rail. Each pair of magnet belt 
conveyor units is preset to be opposite in the direction of circulating 
movement to each other. 
In accordance with still another aspect of the present invention, a 
trailing car, equipped with no magnet belt conveyor units, is coupled to 
the power car and at least one or the other of the power car and the 
trailing car is provided with supporting wheels, which roll over the 
traveling track surface and guide wheels, which roll over the rail to 
guide the car. 
In accordance with still another aspect of the present invention, a 
plurality of such cars compose a train make-up and the leading car and the 
rear car of the train make-up are each comprised of the power car. 
With the magnet-type transportation system according to the present 
invention, the power car is self-movable by its rolling wheels over the 
track surface on both sides of the rail. The rail is made of a magnetic 
material, e.g., steel, and laid down over the traveling track. Driving for 
self-movement of the power car is effected by rotating the magnet belt 
conveyor units mounted on the power car from the power units through the 
power transfer/transmission mechanisms. A train can be formed by coupling 
trailing cars without power units to the power car. In this case, the 
power car and/or the trailing cars are each provided, in addition to the 
supporting wheels which roll over the traveling track, with guide wheels 
which roll over the surface of the rail so as to laterally guide the car 
or cars. 
Each of the magnet belt conveyor units preferably includes a magnet belt 
extended in an endless manner around the driving wheel and the driven 
wheel, each having the vertical rotary shaft. The magnet belt of the belt 
conveyor unit is magnetically attracted, for example, to the side of the 
rail. When the magnet belts are driven into rotation by the power units, 
due to the magnetic frictional force resulting from the magnetic 
attraction force, the belt conveyor units are moved along the rail at the 
circulating speed of the magnet belts and thus the car supporting the belt 
conveyor units is hauled so as to run along the rail. 
The rail is made by forming a magnetic material, typically consisting, for 
example, of a ferrous material, into a given cross-sectional shape of a 
volumetric amount which is sufficient to make the magnetic attraction 
force satisfactory. The sides of the rail form magnetic attraction 
surfaces which are, for example, perpendicular to the traveling track 
surface. For instance, the rail can be constructed by laying a steel plate 
of certain thickness and width in a vertical position along the central 
portion of the car traveling track by a suitable fixing mechanism. Also, 
the magnet belt conveyor units may be mounted on the car in the form of a 
paired construction which are arranged on both sides of the rail. The 
power unit may be composed of any of various motors, such as an induction 
motor, which is fed externally of the car through stringing, a third rail 
or the like and a speed controller. Also the power transfer/transmission 
mechanism may be composed of any of various gearings, whereby the 
mechanical output of the motor is transmitted to the driving wheel of the 
belt conveyor unit and, conversely, the mechanical energy from the belt 
conveyor unit is transmitted to the motor side for the purpose of power 
regeneration. 
In accordance with the present invention, it is only necessary to lay down 
the stationary rail on the ground side without the need to arrange the 
power units and, therefore, maintenance and safety control of the ground 
equipment are easy. Also, the power equipment can be concentrated on the 
car so that when the maintenance and repair are required, the power 
equipment can be carried into and set up in the factory. In addition, any 
variation in the volume of traffic demand can be accommodated by simply 
varying the number of operated cars, the train make-up and the operation 
time interval, and there is no danger of the ground equipment becoming a 
source of noise. Also, the required energy can be reduced to that 
corresponding to the operated cars. 
Also, the present invention is advantageous in that the acceleration, 
deceleration and constant speed operations can be selectively performed 
and the operation speed pattern can be easily varied owing to the 
provision of the speed controller, e.g., a variable-voltage frequency 
converter on the car side. Also the speed oscillation phenomenon during 
the starting period as well as the acceleration/deceleration period can be 
reduced, thus considerably improving the riding comfort. A car, stopped 
due to such an inconvenience as the interruption of service, can be 
started again at any position according to the desired acceleration 
pattern. If the magnet belt conveyor units of the car are constructed so 
that its magnets include permanent magnets, when stopping the car at a 
grade point, the magnet belts are continuously attracted magnetically to 
the rail, thereby making it possible to keep the car at the stopped 
position by means of the braking force of the magnet belt conveyor units 
and eliminating the need to provide the running wheels with a braking 
function. 
It is to be noted that as compared with the conventional magnet-type 
transportation system of the ground-side primary type, the present 
invention structurally eliminates the need for the magnets heretofore 
provided for the respective cars as well as the need for the magnetic belt 
conveyor units heretofore arranged at given intervals on the ground. Also, 
the invention eliminates the need for the forced steering guide tracks 
provided on both sides of the traveling track, thereby practically 
eliminating the occurrence of inconveniences due to the repeated 
application of a torsional force to the guide wheels and other structural 
members on the car side. 
The above and other objects, features and advantages of the present 
invention will become more apparent from the following detailed 
description of its preferred embodiment taken in conjunction with the 
accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIGS. 1 to 3, there is illustrated an embodiment of the 
present invention. In the figures, laid down over a paved traveling track 
11 is a rail 10 made of a steel material (magnetic material) formed into a 
desired cross-sectional profile by roller rolling, for example, and having 
sides which form vertical and continuous magnetic attraction surfaces. A 
car 12 is supported on the traveling track 11 by means of supporting 
wheels 7w which roll over the surface of the traveling track 11 on both 
sides of the rail 10. Arranged below the floor of the car 12 are two pairs 
of right and left supporting frames 2 which are respectively positioned at 
the front and rear portions. Each of the supporting frames 2 is supported 
by a supporting spring 9. A magnet belt conveyor unit 13 is arranged 
within each of the supporting frame. 
The magnet belt conveyor unit 13 includes a driving wheel d and a driven 
wheel i, each having a vertical rotary shaft, and an endless magnet belt 1 
having a plurality of split magnets and an enclosing yoke attached to its 
outer surface and extended around the driving wheel d and the driven wheel 
i, and the magnet belts 1 of the right and left magnet belt conveyor units 
13 are adapted to be magnetically attracted to the sides of the rail 10. 
Attached to each supporting frame 2 are a reduction gear (bevel gearing) 
4, a motor 6 such as an induction motor serving as a driving source and a 
coupling 5 for effecting the transmission of torque between the reduction 
gear 4 and the motor 6. Since the supporting frames 2 support the wheels 
7w with a single shaft structure so that they interfere mechanically with 
the car 12 when a pitching vertical movement is caused during the 
traveling of the car, a supporting roller 3 adapted to roll over the 
surface of the rail 10 is arranged near to each of the front and rear ends 
of the supporting frames 2 so as to prevent such interference. The 
supporting rollers 3 bear the load of the supporting frames 2 which are 
supported by the supporting springs 9, and the supporting frames 2 are 
respectively connected to supporting frames 7s of the supporting wheels 7w 
which, in turn, bear the whole of the car load. 
Thus, in order to obtain more stable magnetic attraction forces which 
externally act on the sides of the rail 10 laid down to extend over the 
traveling track 11, the magnet belt conveyor units 13, which are opposite 
in the direction of circulating motion and form a pair, are arranged at 
each of the front and rear portions of the car body, thereby providing the 
so-called power car according to the present invention. It is needless to 
say that trailing cars having no power systems, i.e., magnet belt conveyor 
units, electric motors, etc., can be coupled to the power car to make up a 
train. 
In this case, as the magnet belt conveyor units of the power car, it is 
generally preferable to use magnet belts, which are readily flexible to 
correspond to the curved configurations of the rail 10, in the curved 
sections, including the grade sections, without the application of any 
special tension to the magnet belts instead of magnetic belt conveyor 
units of the heretofore known type employing the intermediate guide 
rollers which guide and bear the circulating movement of the magnetic 
belts. By so doing, it is-no longer necessary to steer and guide the car, 
or a plurality of the cars connected to form a train, by a forcible 
external force due to the interaction between the guide wheels and the 
guide wall as in the case of the conventional magnet-type transportation 
system of the ground-side primary type. Particularly, in the case of the 
ground-side primary type of system, the magnetic belt conveyor units are 
arranged in the broken-line configuration in the curved sections, as well 
as at the grade entrance and exit locations, so that the previously 
mentioned forcible external force becomes excessively large as compared to 
that for the straight sections and a torsional force acts between the car 
body and the magnets attracted to the magnetic belts. The present 
embodiment does not produce such problems. 
With the present embodiment, the addition of the speed controller, such as 
a variable-voltage frequency converter for making the circulating speed of 
the magnet belt conveyor units 13 of the power car variable, permits one 
to selectively effect the variable speed operation and the constant speed 
operation. 
Further, where the power car of the present embodiment is coupled to 
trailing cars to make up a train, it is advantageous to use the 
illustrated power car having the independent functions only on the forward 
side in the travel direction and then couple to it trailing cars on the 
rear side through, for example, coupling devices 8 with the interposition 
of for example, an elastic material. In this case, each of the trailing 
cars is provided with a plurality of pairs of guide rollers for steering 
and guiding it along the sides of the rail 10. 
Where the traveling track 11 is not a loop traveling track and a turn-back 
operation of cars is performed on the same traveling track, it is only 
necessary that the power car having independent functions is arranged at 
each of the forward and rear sides of the train or the ends of the train, 
whereas if the train make-up is longer, a suitable number of the power 
cars may be advantageously coupled to the intermediary portions. In either 
of the cases, it is only necessary to construct the drive system of the 
magnet belt conveyor units 13 of the power cars in such a manner that the 
direction of circulating movement of the magnet belts 1 can be reversed.