GB2238520A

GB2238520A - Transport system using linear induction motors

Info

Publication number: GB2238520A
Application number: GB8927307A
Authority: GB
Inventors: Jean Guimbal
Original assignee: Individual
Current assignee: Individual
Priority date: 1988-06-03
Filing date: 1989-12-02
Publication date: 1991-06-05
Also published as: FR2632259B1; FR2632259A1; DE3940380A1; GB8927307D0

Abstract

An automatic transport system comprises an active electric track constituted by a succession of linear induction motors 13 or axial motors distributed along the track between the rails 5 on which the vehicles of the system circulate and, on each vehicle, a mobile armature constituted by a longitudinal section of upturned U or omega cross-section, this system being characterized in that blocks of elastic material, for example rubber, are interposed between the base plate of the rails and the structure eg girders 1 supporting the latter, and the motors are fast with ties 11 connecting the rails. Each motor 13 is mounted on an equipment box 12 via a support plate 16 which is a good electrical conductor forming a screen against parasitic magnetic fluxes. The chassis of each vehicle comprises four assemblies of two wheels each, each assembly being mounted for pivoting about a vertical axis. The wheel assemblies on one side of the chassis comprise flanged wheels and those on the other side wheels without flanges. An emergency braking device acts in the event of excess speed at a terminal station, the braking effect being achieved by a wedging action between a shoe associated with a wheel and friction linings on the rail. <IMAGE>

Description

-I- AUTOMATIC TRANSPORT SYSTEM -- E3 E5 2 G3 2:2 - T he present invention

relates to an automatic transport system employing an active electric track, constituted by a succession of linear induction motors or "axial" motors distributed along the track, between the rails on which the vehicles of the system circulate.

Linear induction motors or axial motors are already known, as described in particular in Appli- 1.0 Cant's Patent FR-A-2 105 955. Such motors comprise, on the one hand, a fixed inductor, simply referred to hereinafter as "motor", fast with the track, and a mobile armature, fast with each vehicle, constituted by a longitudinal section with an upturned U or omega V, cross-section. The inductor or "motor" is constitutod by a winding composed of rectangular coils disposed one after the other, in the longitudinal direction, around a laminated core, with the interposition of rectangular teeth between the coils, this assembly being borne by a lower horizontal plate made of a material which is a good conductor of electricity, which forms a screen with respcct to the parasitic magnetic fluxes. An active clectric track of such a transport system comprises a succcssion of such 2." axial motors spread along the track, between the rails. Upon departure from each station, acceleration of a vehicle is obtainod thanks to a succession of motors which are actuated one aftor tho other at the moment. when the wheels of the vehicles pass in the zone where they are located, by means of proximity detectors. Along the path, other motors, con'.-rollod in the same mannert maintain the soced, if necessa.,y. Finally, upon arrival at the stations, motors which, if it is a single track, may be the same as those ensuring acceleration in opposite direction, ensure slowing down and stop of the vehicle by a braking operation either by injection of direct current or by reversing the direction of the sliding magnetic field.

A transport system thus produced is particularly economical since the axial motors that it employs have such a favourable thrust/cost ratio that, despite their high number, the whole motorization system is much less expensive than with a conventional solution, particularly taking into account the considerable lightening of the sets of vehicles allowed by the simplicity of the equipment embarked.

The need to maintain a small air gap between the fixed inductor of the. axial motors placed on the track and the mobile armature of each vehicle prevents providing a primary suspension between the axles and the chassis of eac.n vehicle.

SUMMARY OF TI1E INVENTION

In order to overcome this drawback, blocks of elastic material, for example rubber, are interposed, according to the invention, between the base plates of the rails and the structure supporting the latter, and the motors are fast with ties connecting the x7ails. In this way, the elastic blocks on which the rails rest, may subside under noteworthy load wj.tiiuut this being detrimental to the precision of the air (gap.

Furthermore, the sets of vehic)es of the public transport systems must be able to accept the low-radius curves of the track. This resuJt is conventionally obtained by supporting the vehicles on bogies with small wheel base. Hos,,ever, in the caso of the system accQrding to the invention, this arrangement is not compatible with the presence of the armature which extends longitudinally, between the wheels, over 11 1 the whole length of the vehicle. Consequently, in accordance with a complementary feature of the invention, each vehicle comprises a chassis presenting, instead of the usual four wheels, four assemblies of two wheels each, the two wheels of each assembly being disposed one after the other in the same vertical and longitudinal plane, and each assembly of two wheels comprises a wheel support mounted to pivot, on the chassis side( about its vertical axis of symme- try. The two wheels oft each assembly may be provided with wheel flanges ensuring guiding of the assembly and the pivoting movement thereof in the curves. According to a particular embodiment of the invention, the wheel assembliez located on one side of the chassis comprise wheels with two flanges enframing the rail and they are therefore guided by these flanges, whilst the wheel assemblies located on the opposite side, comprise wheels bereft of flanges and their supports are coupled to the supports of the flanged wheel assemblies located on the first 5idc,, so as to pivot jointly therewith. Connection between the supports of the wheel assemblies located respectively on the two sides of the chassis is advantageously provided)Dy a transverse bar fixed, at its two ends, to the supports of the wheels of the two assemblies.

The very principle of the axial motors leads to elongating their cross section in the direction of their axis of symmetry, this cross section having a rectangular shape. According to the invention, the motors are disposed so that their vertical plane of symnietry merges with the vertical plane of symmetry Qf the track, their rectangular cross section in that case being elongated in the vertical direction.

The effect of such an arrangement, if the trans- port system comprises a single track with a terminal iiw-_ loop at each end of the line, is that the relative position of the armatures of the vehicles and of the fixed motors is not modified whatever the direction of displacement of the vehicle on the track. Further- morei as the rectangular cross section of each motor is elongated in the vertical direction, the lower screen support is horizontal and, according to a complementary feu'-uz:e of the invention, this arrange ment renders assembly very economical, by giving to the lower screen support the shape of a plate serving as cover for a subjacent control box. In that case, the conductors for connecting the coils have only the cover to traverse inorder to penetrate in the control box where they are directly connected to the terminals of an appropriate contactor.

In a transport system of the type described hereinabove, the motive force as well as the brake force inust be adapted to the load of the vehicle.

tained according to the invention This result may be obt by providing means for weighing each set of vehicles before launching and for t.,zaisl.ating the result of the weighing in the form of a voltage of desired value sent tu Lhe motors and brake motors in questinn. The 4eflection of the steel frame supporting the track, ill: the IdLLer is overhead, elastic blocks, or sensors with strain gauge bearing tile frame, may be used for weighing the set of vehicles.

In the transport system according to the, invention, a safety device is Mso provided, which ovecorno.s a possible shortuuittii.tg of the normal braking device by using the fact that an excess of speed increases the centrifugal force exerted on the set of vehicles itself further to the presence of a curve. To that end, at the entrance of each station, the curve which allows the single track to be divided into two scissors 1 1 1 i r,ross-overs in order to allow intersection is used, Cand, at the bottom of the descending gradients, a curve is provided which is allocated, especially or not, to this function. In that caset there is provided in this zone a guiding rail which is slightly narrowcd to allow a lateral displacement of the chassis of the vehicle and wedges borne by this vehicle may then be wedged between the V-shaped bands borne by the guiding rail, the wedges or the longitudinal bands of V-cross section being coated with friction linings. It is the angle of the V and the value of the coefficient of friction of the friction linings which make it possible to adjust the deceleration to the desired value.

is The transport systei,,,i according to the invention, as indicated hereinbefore, may comprise a single track connecting the stations, the sets of vehicles intersecting either in all the stations or only in part of them. Thanks to the use of linear mot-ors fixed on the triack, safety is much better than with the conventional solution, since, as the motorization 15 fixed, it is no longer necessary to provide a transmission to each set of vehicles of the indications of position of the preceding set of vehicles and 2SQf the one. that it will cross. In order to eliminate - suffices to arrange, in any risk of collision, 1+. the stations of intersection, for a set of vehicles located on a scissors cross-over not to leave as long as the indicators of position of the set of 1Ovehicles located on the other scissors cross-over do not indicate that the set of vehicles which will be crossed is effectively present on this other scissors cross-over.

The invention will be more readily understood on reading the following description with reference tu the accompanying elrawings, in which:

Figure 1 is a view in pereepective of a section of track of the transport system according to the invention.

Figure 2 is a perspective view, with parts torn away, of a brake motor.

Figure 3 is a view in perspective of the chassis of a vehicle circulating on the track of the transport system.

Figure 4 is a partial vertical and transverse sectional view illustrating an emergency braking device.

1,5 Referring now to the drawingsr Figure 1 shows a section of track of a transport system according to the invention. The transport track which will be described hereinafter is overhead, but it goes without saying that the invention may equally well be applied to a track laid on the ground or to an underground track. The overhead track shown in rigure, 1 im L;kjai.-,LiLutczl tsy herizontal qirderc 1, parallel to one another, which are held by clamping Lhanks to gussets 2, on ties 3 which themselves rest on 2b pdsts 4. Rails 5 resIL un the lower-horizontal flangck-la of the girders 1, inside the latter via blocks 6 of elastic material, for example rubber, which are clamped between upper shells 7 connected to the base plates of the rails 5 and lower shells 8 connected to surbased ties 9. These surbased ties 9 are located between the ties 3 supporting the girders 1, they are maintained by r.lirr.1)ing on the lower flange. la of each girder 1 and they bear a grating 10 for circulation. The parallel rails 5 are itiairitdiiix--cl at the P5desired distance by tubular ties 11 fixed to the -I- rails at their two ends. To theses tubular ties 11. are fixed equipment boxes 12 which extend lonqitudinally between such ties 11. Each equipment box 12, generally parallelepipedic in shape, bears, on its upper surface, an axial electric motor 13 disposed exactly in the middle of the track. Each axial motor 13 has a parallelepipedic shape, elongated in the longitudinal direction and of which the vertical and longitudinal plane of symmetry merges with the vertical and longitu- dinal plane of symmetry of the track. The motors 13 are distributed along the track, at a distance from one another, to create a sliding magnetic field accelerating a 7ohicle, maintaining the speed of this vehicle, or, on the contrary, braking this ve- hicle. Each motor 13 or brake motor is supplied electrically by linking conductors 14 which pass in the tubular ties 11 and arc! connected to cables 15 which extend between the rails 5 and the girders 1. Each axial motor 13 comprises, in its lower part-f a support 16 constituted by a horizontal platc, made of a material which is a good conductor of electricity, forming a screen with respect to the parasitic magnetic fluxes. Proximity detectors 17 are located on t1he sides of these screen supports 16.

As may be more readily seen in Figure 2, the brake motor 13 is constituted by a winding composed fter the other, of rectangular coils -3a disposed one a. in the longitudinal direction, around a laminated core 13b, with the interposition of rectangular te.c.th 3(- 13c between the coils, this assembly buing borne by the lower horizontal plate 16 constitUting itS screen support. The lattcr forms the cover of the equipment box 12 of which the undulated flanks 18. form radiator fins. The screen support 16 may also 35be placed on the. upper horizonta) part of the box 12 which ensures a good thermal contact with the screen support 16 of the motor 13. The part torn away in the wall of the box 12 makes it possible to see# inside this box, two contactors 19 and 21 as well as, therebetween, a section switch 22 with fuses. The conductors for connection of the coils 13a of the motor 13 pass through the screen support 16 forming cover in order to penetrate in the box 12 where they are directly connected to a contactor 19, 21. Furthermore, the proximity detector 17 projects reen support 16 which upwardly with respect to the sc. it traverses.

Figure 3 shows a-chassis'23 of a vehicle circulating on the track. This chassis 23 beas, in its central, lower parti an armature 24 extending over virtually the whole length of the chassis and which is constituted by a section whose vertical and transverse cross section may be either in the form of an upturned U, or, as illustrated in Figure 3, in omega form. This armature 24 which moves above the successive axial motors, as may be more readily seen_ in Figure 4, is coated with an inner layer 25 of a material which is a qood conductor of electricity. It is fast, near its ends, with tubular ties 26 of which each end bears a pair of vertical, transverse plates 27. Each pair of vertical, transverse plates 27 of a tie 26 in turn boars, at its outer end, two vertically aligned bearings, namely an upper bearing 28 and a lower bearinq 29. in each pair of bearings '28 and 29, there is pivotally mounted, arQund the vertical axis of the two bearings, a wheel support assembly 31. This wheel. support 31 is constituted by two vertical, longitudinal plates 32 supporting the horizontalt transverse rotation shafts of two wheels 33 located in the saine vertical? longitudinal 1 01- pldfic,, Letween the Lwo plates 321 On L- i t 11 #-,.T A i cl c. of the pivot axis of tltk,- support il. All the wii(-..L.Ib may be provided with flanges 33a or only the wheels located on the same side of the chassis may each be prQvided wiL]i Lwo flanges 33a, an nhown in Firjures 3 and 4, so as to ensure lateral guiding of the chassis 23 in tho two directinng. Tn this case, the wheel supports 31 located on the two sides of the chassis 23 are connected to each other by means of a transverse connecting bar 34. Elastic suspension members 35 are piaced vertiedlly bi- -Lw,-cn the vcrtical., transverQe plates 27 in order to support the box body (not shown) of the vehicle., Transverse anti-roll bars 36 are mounted in fork joints 37 fixcd on the transverse is plates 27 and they are connected to the body of the vehicle via arms 38. Levers 39 controlled by emergency doors of the cabin (not shown) attack threaded rods 41 and cause immobilizing shoes 42 to descend on the rails 5 in the event of emergency.

Figure 4 shows an emergency braking device which acts, in the event of excess of speed at a terminal station or, which comes to the. same, at. the first curve encountered by a vehicle. arriving at a junction _station, i.e. the one which moves the two tracks away from one another. The gJ-rdcr 1 bears the rail 5 on which the wheel 33 with two flanges 33a rolls. The rotation shaft of the wheel 33 is supported, at its endst by the two vertical, longitudinal plates 32 of the wheel support 31 mounted to pivot oil tile end of the tie 26. The vertical, longitudinal plate 32 which is located ovitside. the wheel 33 and the rail 5, bears, in its lower end part which is downwardly extended along the rail 5, a shoe. 43 in the form of a wedele extending in the direction of the vertical web of the rail 5, outside the latter. When the wheel makes up its clearance a between its outer flange 33a and the upper part of the rail 5, by moving towards the left in Figure 4, this wedge 43 engages between friction linings 44 borne by two upper and lower longitudinal bands 45 and 46, respectively, fixed on the outer vertical face of the web of the rail 5 and which are inclined respectively upwardly and downwardly. In this way, the vehicle is braked further to the friction of the wedge 43 on the friction linings 44. In accordance with a variant embodiment, the friction linings 44 may, of course, be provided on the wedge 43.

The transport system according to the invention naturally comprises cabins with sliding doors provided.

with a locking device actuated by means provided at each station where a vehicle stops. These means unlock each door when the vehicle has stopped at the station and they prevent any start if a door remains open.

z 1 1

Claims

CIAIM9,

1. in an autoinatic transport system an active elcutriu track constituted by a succession of linear induction motors or axial. motors distributed along the track between the rails on which the vehicles of the system circulate and, on each vehicle, a mobile armature constituted by a longitudinal section of upturned U or omega cross-section, blocks of elastic material, for example of rubber, are interposed between the base plates of the rails anA thr. gtrtlntiirp Aiil)pnrt..ng the latter. and the motors are fast with ties connecting the rails.

2. The system of Clain 1, wherein each axial motor comprises, in its lower part, a support constituted by a horizontal plate made of a material which is a good conductor of electricity, forming a screen with respect to the parasitic mignc--,tic fluxes, this screen support constituting the cover of a subjacent equipment box supporting the motor or being placed on the upper horizontal part of the box en suring a good thermal contact, and the conductors for connection of the coils of the motor pass through the screen support to penetrate in the box where they are directly connected to the ter-minals of a contactor.

3. The system of claim 2, wherein a proximity detector projects upwardly with respect to the screen support which it traverses.

4. The system of any one of the preceding Claims, wherein the chassis of each vehicle comprises four assemblies of two wheels each, the two wheels of each assembly being disposed one after the other in the same vertical, longitudinal plane, and each wheel assembly comprises a wheel support mounted to pivot, on the chassis side, about its vertical axis of symmetry.

5. The system of Claim 4, wherein the wheel assemblies located on one side of the chassis comprise wheels with two flanges encompassing the rail, whilst the wheel assemblies located on the opposite side, comprise wheels bereft of flanges and their supports are-coupled to the supports of the flanged wheel assemblies located on the first side, so as to pivot jointly therewith, connection between the supports of the wheel assemblies located respectively on the two sides of the chass!5 advantageously being effected by means of a transverse bar fixed, at its two ends, to the supports of the wheels of the two assemblies.

6. The system of any one of the preceding Claims, wherein the motors are disposed so that their vertical plane of synimetry marges with the vertical plan(-, of symmetry of the track, their rectangul.-Ar cross section being elongated in the vertical direction.

7. The system of any one of Claims 4 to 7, wherein each wheel support which is mounted to pivot oil the chassisr about a vertical axis, comprises two vertical, longitudinal plates between wliiuli the whecels are located and of which the one located outside tile wheel and the rail boars, in its lower end part which is extended downwardly along the rail, a shoe in the form of a wedge extending in the direction of the vertical web of the rail, outside the latter, and the rail presents, in a curved part where an 1 1 1.

-is- excess of speed may tie produced, two upper and lower longitudinal bands, fixed on the outer vertical face of the web of the rail., which are inclined respectively upwardly and downwardly and between which the wedge I-icirnn by the outer. vertical, 1Qngitudinnl plate, may engaget under the effect of a centrifugal force due to an excess of speed, the wedge or the bands bearing friction linings.

8. The system of any one of the preceding Claims, wherein means are provided for weighing each set of vehicles before launching and for translating the result of the weighing in the form of a voltage of desired vallue sent to the motors and br.dki-- tituLuz..-j in question.

9. The system of any one of the preceding Claims, wherein it comprises position indicators which prevent the departure of a vehicle in a junction station if the set o. vehicles arriving in tho oppos-te direction on the other Itrack- oe the station is net preseni, on this track.

10. An automatic transport system substantially as herinbefore described, with reference to the accompanying drawings.

published 1991 at 'fbe Patent Offlee. State House. 66/71 High Holbom, London WCIR47P. Further copies may be obtained from Sales Branch, Unit 6. Ninc Mile Point, Cwmfelinfach. Cross Keys. Newport. NPI 7HZ. Printcd by Multiplex techniques ltd, St Mary Cray. Kcnt.