WO1992003322A1

WO1992003322A1 - Drive for an aerial cableway

Info

Publication number: WO1992003322A1
Application number: PCT/EP1991/001527
Authority: WO
Inventors: Götz Heidelberg; Peter Ehrhart; Andreas GRÜNDL
Original assignee: Magnet-Motor Gesellschaft Für Magnetomotorische Technik Mbh
Priority date: 1990-08-14
Filing date: 1991-08-09
Publication date: 1992-03-05
Also published as: EP0542839B1; DE4025736A1; DE59108639D1; EP0542839A1; ATE150711T1

Abstract

A drive for an aerial cableway is characterized in that permanent magnets (20) of alternating polarity are disposed in a circle on the drive pulley (14) of the aerial cableway, in that the permanent magnet (20) has a stationary annular stator with wound stator poles (10) from which it is separated by an air gap (26), and in that an electronic control unit (66) for precisely timed switching of the stator poles (10) is provided.

Description

Cable car drive

The invention relates to a cable car drive, in which permanent magnets of alternating polarity are arranged on the drive cable pulley of the cable car, a permanent, ring-shaped stator with wound stator poles is provided opposite the permanent magnets, leaving an air gap, and an electrical control unit for timely use Switching the stator poles is provided.

So far, cable cars have been driven by means of a conventional electric motor via an intermediate gear. The electric motors are heavy and expensive. In addition, there are only limited control options, for example for the speed of the rope or the acceleration of the rope.

The object of the invention is to make a cable car drive with a simple, con igurative structure and significantly better control options available.

The permanent magnets, the wound stator poles and the associated electronic control unit form a commutatorless, electronically controlled drive, the control unit preferably receiving control signals from one or more sensors which continuously detect the rotational position of the motor or the pulley relative to the stator. ^" All sensors are particularly suitable for this. This drive is most likely to be compared with a synchronous motor from the motor function. as will become clearer below.

The air gap between the pole faces of the permanent magnets and the pole faces of the stator poles can have an essentially cylindrical or an essentially flat configuration, namely at right angles to the axis of rotation or at an oblique angle to this configuration. The stator poles can be provided radially outside and / or radially inside and / or axially spaced from the permanent magnet poles. The mean diameter of the air gap can be smaller, larger or equal to the diameter on the sheave on which the rope is located.

The electronic control offers a variety of control options, of which particularly outstanding are explained in more detail below.

There are two preferred options for attaching or arranging the stator. Either the overall substantially ring-shaped stator is arranged on a disk-like support part which is connected to a support column that rotatably supports the rope pulley. Or the stator is separately supported by the sheave, in particular anchored to the ground, a building or the like.

An important characteristic of the cable car drive according to the invention is that - with practically no disadvantages - it is possible to work with significantly larger gap widths or gap thicknesses than with conventional electric motors. As a result, the stator poles and the permanent magnets can be arranged with the dimensional tolerances common in steel construction, which is what drives the cable car significantly cheaper. Specifically, air gap thicknesses of at least 2 mm, preferably 2 to 5 mm, are preferred.

The permanent magnets preferably consist of ferrite material, samarium-cobalt material or iron-neodymium material. The last-mentioned permanent magnets in particular are characterized by a high coercive force and insensitivity to opposing fields, i.e. the magnetic fields of the stator coils.

It is preferred to occupy only a partial circumferential area of the drive with the stator in such a way that there is an attractive force which is opposite to the direction of the cable pull and relieves the bearing of the cable pulley.

The invention further relates to a cable car drive in which a planetary gear is connected to the drive pulley of the cable car; an annular stator with wound stator poles is provided on the fixed, internally toothed ring gear of the planetary gear; with the driving shaft of the planetary gear, a support member for annularly distributed permanent magnets is connected, which are opposite the stator poles with the release of an air gap; and an electronic control unit is provided for timely switching of the stator poles.

In this case, the drive according to the invention, consisting essentially of wound stator poles, permanent magnets and electronic control unit, is connected to the internally toothed ring gear of a planetary gear. arranges instead of the rope pulley. Here too, the advantages of saving a conventional electric motor and the improved and expanded control options remain. The storage of the rope pulley or the internally toothed ring gear also takes over the rotational mounting of the rotor of the drive. The Tragreii for the permanent magnets is preferably substantially pot-shaped.

Preferred configurations of the electronic control of the drive according to the invention are addressed below.

The electronic control unit preferably has a plurality of converter modules, each of which switches part of the stator coils. In this way, each converter module only has to control a smaller current; the sum of the converter modules is cheaper than a common converter for the entire drive. In addition, the drive remains functional even if individual converter modules fail, albeit with reduced power. Four-quadrant converters or four-quadrant actuators are particularly suitable for the switchable converter modules.

The cable car drive preferably has an electrical braking device which, in order to exert a braking force on the cable, switches the converter or converters of the electronic control unit to braking operation and either supplies the current induced in the stator coils via at least one braking chopper or at least one braking resistor the otherwise feeding network returns. The electric braking device causes preferably with the involvement of the electronic control unit, a supply or timely switching of the stator coils such that the drive generates a braking torque in the opposite direction to the drive torque in the case of the drive function. In this case, electrical power is fed from the stator coils to one or more braking resistors or fed back into the otherwise feeding network. The electrical braking device can be integrated in the electronic control unit or can be a separate braking unit that interacts with the control unit. The additional electrical effort for the electric braking device is small; overall, the effort is much less than with a mechanical service brake and the electric brake operates without wear. As a rule, there is also a mechanical brake system, in particular as a safety brake or as a fixed-brake-brake. Feeding back into the power grid is particularly useful when the (transportable) rope transport units are descending in the evening.

A memory for a plurality of driving programs, which can be selected selected, is preferably assigned to the electronic control unit. The different driving programs can relate in particular to different driving speeds, different starting accelerations, different braking decelerations or the like.

Furthermore, it is preferred to assign a travel program memory to the electronic control unit, which contains a travel program with periodically higher rope speed and lower rope speed, whereby - 5 -

the low rope speed is assigned to those times in which the transport units movable with the rope pass through sections of the route for getting in and out or loading and unloading. In this way, the travel speed of the transport units can be increased in times when no transport unit travels through a section of the route for boarding and disembarking or loading and unloading, that is to say overall increasing the capacity of the cable car.

The cable car drive preferably has an electronic holding device which controls the current in the stator coils for a brief standstill of the cable in such a way that the required holding torque is generated. As a result, it is possible to work for a brief stop without activating a mechanical brake. This is particularly favorable in the situation when a transport unit of the cable car is in a section of the route for getting on and off or getting on and off load located. The limit of the time period below which the mechanical brake system is not activated is preferably adjustable.

Position sensors are preferably connected to the electronic control unit, which are arranged on the route sections for getting on and off or loading and unloading the transport units that can be moved with the cable, so that deceleration, stopping, slow travel, acceleration or the like takes place as a function of position sensor signals . The cable car drive according to the invention is particularly suitable for cable cars for transporting people or loads from a lower to a higher position, very particularly the most varied designs of lifts for the transport of skiers or hikers, such as part lifts, bow lifts, chair lifts, cabin cable cars. However, other transport systems in which a rope is to be driven can also be equipped with the drive according to the invention, for example in mines with a vertical or oblique direction of movement of transport baskets.

It is pointed out that the preferred control configurations specified in claims 7 to 12 can also be realized according to the invention also in cable car drives which otherwise do not have the features of at least one of claims 1 to 6. An electronically commutated permanent magnet electric motor for driving a cable car is mentioned as an example, which is conventionally located in the vicinity of the cable pulley and drives it directly or via a gear.

The (average) air gap diameter of the cable car drive is preferably larger than the cable trough diameter.

The invention and refinements of the invention are explained in more detail below with reference to exemplary embodiments, some of which are shown schematically. It shows:

Figure 1 a cable car drive in section and partially broken away.

2 shows an alternative embodiment of a cable car drive in a schematic representation, likewise in section and partially broken away;

3 shows a schematic plan view of a cable car drive similar to the embodiment from FIG. 1 with the cover hood omitted;

4 shows an alternative embodiment of a cable car drive in section;

Fig. 5 details of an electronic control for a cable car drive.

In the first embodiment of the cable car drive according to FIG. 1, a vertical, hollow support column 2 having several sections can be seen, to which a horizontal, disk-like support part 4 of large diameter is fastened in the upper end region. The supporting part 4 can have an upper and a lower, circular plate or can be designed with radial struts and a circular circumferential edge part. A generally substantially annular stator 6 is fastened to the outer circumference of the support part 4. The stator 6 offers discrete pole faces 8 pointing radially outwards Stator poles 10 are each wound with a coil 12.

A horizontal cable pulley 14 is arranged below the support part 4 and is rotatably mounted on the support column 2. The rope pulley 14 is essentially made up of radial struts, a circumferential rim radially on the outside, a circular rope trough 16, stiffening ribs and an inner bearing sleeve. The circumferential ring 18 projects radially upward radially outside the stator 6 fastened to the supporting part 4. On the inner circumference of the circumferential ring 18 permanent magnets 20 with alternating polarity are attached in a ring-shaped manner. The permanent magnets are attached to a radially outer magnetic return ring 22.

The permanent magnets 20 provide permanent magnetic pole faces 24 directed inwards. The stator pole faces 8 and the permanent magnetic pole faces 24 face each other, with an essentially cylindrical air gap 26 with a radial width or thickness of approximately 2 between these pole faces 8, 24 , 5 mm.

The diameter of the cable tray 16 is approximately 60 to 90% of the diameter of the air gap 26. However, it is entirely possible to make the diameter of the cable tray 16 smaller or larger, for example larger than the diameter of the air gap 26. In the cable tray 16 this is to be driven rope 28 of the cable car.

It is alternatively possible to provide the pole faces 8 of the stator 6 downward and the pole faces 24 of the permanent magnets 20 pointing upward, as a result of which an annular, flat air gap 26 is created. It is also an alternative possible to provide the permanent magnets 20 radially within the stator 6. Finally, it is alternatively possible to watch the rope pulley 14 above the supporting part 4. The power supply lines 30 to the stator 6 are guided radially inward on the stationary support part 4 and then down through the hollow support column 2. A cover 56 covers the drive from above.

The electronic control unit, which will be explained in more detail below, ensures that the direction of the current flowing through the individual coils 12 is reversed by a permanent magnet pole pitch after each further rotation of the rope pulley 14, a sensor on the support part 4, which will be explained in more detail later, changing the respective rotational speed - Determines the position of the pulley 14 relative to the support member 4 and gives corresponding control signals to the control unit.

It is pointed out that preferably the number of stator poles 10 and permanent magnet poles 24 does not exactly match, but for example one, two or three permanent magnet poles 24 are present more or less than stator poles 10. Due to the electronic control, the stator poles 10 can nevertheless be switched over at the correct time, and the drive runs more smoothly.

The most significant difference between the second embodiment of the cable car drive according to FIG. 2 and the first embodiment is that the stator 6 is not fastened to a supporting part fastened to the support column 2, but rather to supports 32 which are distributed in a ring and fastened to the ground In addition, the Variant drawn in that the stator 6 has both radially inward and radially outward facing stator pole faces and that both permanent radially inside and radially outside of the stator 20 are attached to the rotating pulley 14. Finally, it can be seen that in this embodiment the cable tray 16 is provided radially outside the stator / permanent magnet arrangement.

2 illustrates the possibility that the stator 6 - here radially outside the disk 14 with the permanent magnets - extends only over a partial circumferential area, namely over a circumferential length of approximately 130 "U. This creates between the stator 6 and a radially directed attraction force to those permanent magnets which are located directly opposite the stator 6. The partial circumferential region equipped with the stator 6 is positioned in such a way that this magnetic attraction force 34 is opposed to the cable tensile force, so that the bearing of the rope pulley 14 is relieved results.

The main difference between the third embodiment shown in FIG. 4 and the previously described embodiments is that the stator / permanent magnet arrangement is not directly associated with the pulley 14, but with the internally toothed ring gear 36 of a planetary gear 38. A generally substantially annular stator 6 with discrete stator poles wound with coils is attached to the outside of the circumference of the ring gear 36. The permanent magnets 20 sit radially outside of the stator 6 opposite this on the inner circumference of a generally pot-shaped support part 39. The overall also essentially Pot-shaped ring gear 36 is attached to a stationary plate 40 on its open top. The supporting part 39 is rotatably mounted on a downwardly projecting, hollow extension 42 of the ring gear 36. The input shaft 44 of the tarpaulin engetriεbes 38 is rotatably connected to the support member 39. The input shaft 44 leads through the hollow extension 42 into the interior of the planetary gear 38 and is provided with pinion teeth in the end region there. Several circumferentially distributed planet gears 46 mesh on the inside with this pinion toothing and on the outside with the inner toothing of the ring gear 36. The planet gears 46 are rotatably mounted on a planet carrier 48. The planet carrier 48 has an upwardly projecting, wave-like extension 50, which is mounted in the interior of a vertical, stationary support column 52, which in turn is fastened on top of the previously described plate 40. The horizontal cable pulley 14 is mounted on the outside of the bearing column 52 and is connected to the shaft-like extension by a connecting plate 54 above the upper end of the bearing column 52 in a torque-transmitting manner. The rope pulley 14 has the rope trough 16 on the outer circumference. From below, the rotating support part 4 is covered by a hood 56.

The tight integration of the drive into the planetary gear 38 achieved and the resulting compact design can be seen. Due to the considerable speed reduction by means of the planetary gear 38, a geometrically smaller stator / permanent magnet arrangement results — measured in terms of the torque required to drive the cable 28. A preferred embodiment of the electronic control is explained with reference to FIG. 5.

Current from a power grid 60 flows via a grid feed 62 to a grid current rectifier 64 and from there to an electronic control unit designated overall by 66. The rotational position of the rotor of the drive, i.e. the pulley 14 or the support member 39, in relation to the stator 6. The control unit 66 has several — in the example shown six — electric converter modules 70, each of which switches a group of stator poles or stator coils. The signals from the sensor 68 are processed in a converter control 72 of the control unit 66, and the converter control 72 in turn controls the converter modules 70. In this way, the individual stator coils are supplied with current pulses in the correct time and with the correct sign.

The control unit 66 also contains a memory 74 for a plurality of driving programs, a driving control 76 and interfaces or connections 78 for external detectors, which are collectively designated 80 and peripheral devices. An operating unit is designated by 82, and 84 collectively denotes signal units.

One of the driving programs can be selected from the memory 74 by means of the operating unit 82. The selected drive program acts on the converter control 72 via the drive control 76. Commands given by hand, such as “stop”, “forward”, “reverse” or “slow travel”, are also transmitted to the converter control 72 via the drive control 76. Examples of possible, different driving programs have been given ahead.

External detectors 80 are, in particular, position sensors which deliver signals such as "a transport unit is currently passing point A" or "no transport unit is currently at point B", or temperature sensors in the area of the stator, which determine an overload or emergency switch, for example in response to the failure of a cooling fan for the control electronics or to faults on the cable car route. The signal units 84 are, in particular, displays for the operator, for example for the current driving speed, the distance traveled by transport units or the like.

A brake chopper is designated by 86, which is connected to the power connection between the rectifier unit 64 and the control unit 66 (DC voltage intermediate circuit). If the control unit 66 is given a "brake" command by hand or from the drive program, the drive modules 76 are controlled with the cooperation of the drive control 76 and the converter control 72 so that the stator coils 12 are supplied with current at such times in such a current direction that the Drive delivers a braking torque instead of a driving torque. This is accompanied by an electrical power flow from the stator coils 12, which is either supplied to the braking resistors 88 via the braking chopper 86 and / or is fed back into the network 60. In the latter case, the rectifier unit 64 is designed as a reversing converter. As already mentioned above, the control unit 66 can be connected not only to external position sensors, but also to other external sensors, for example proximity sensors. It is possible to use the control unit 66 to record the cable route covered and to use this as a feedback signal for the driving programs or the manual control. The control unit 66 normally regulates to a specific drive torque. 3If a specific set target speed is specified manually or by the drive programs, this is converted internally to a required drive torque. In addition to the converter modules 70, the control unit 66 is preferably constructed with microprocessors.

The rope pulley 14 can be rotatably mounted on a larger diameter than shown in FIGS. 1, 2 and 4. The rail track drive is preferably a unit which is mounted as a whole on foundations.

Claims

Patent claims

1. Cable car drive, characterized in that permanent magnets (20) of alternating polarity are arranged on the drive pulley (14) of the cable car in a ring shape; that a permanent, ring-shaped stator (6) with wound stator poles (10) is provided opposite the permanent magnets (20) while leaving an air gap (26); and that an electronic control unit (66) for timely switching of the stator poles (10) is provided.

2. Cable car drive according to claim 1, characterized in that the cable pulley (14) is rotatably mounted on a support column (2) and that the stator (6) is attached to a disk-like support member (4) connected to the column (4) is ordered.

3. Cable car drive according to claim 1, characterized in that the stator (6) is separately supported by the pulley (14).

4. Cable car drive according to one of claims 1 to 3, characterized in that the thickness of the air gap (26) is at least 2 mm, preferably 2 to 5 mm.

5. Cable car drive according to one of claims 1 to 4, characterized in that the stator (6) extends only over a partial circumferential area such that one of the

Direction of pull in the opposite direction, relieving the bearing of the pulley (14).

6. Cable car drive, characterized in that a planetary gear (38) is connected to the drive pulley (14) of the cable car; that an annular stator (6) with wound stator poles (10) is provided on the stationary, internally toothed ring gear (36) of the planetary gear (38); that with the driving shaft (44) of the planetary gear (38) a support member (39) with an annular distribution Permanent magnet (20) is connected, the d εn atoratorpolen (10) opposite with the release of an air gap (26); and that an electronic control unit (66) is provided for the timely switching of the stator poles (10).

7. Cable car drive according to one of claims 1 to 6, characterized in that the electronic control unit (66) has several current directional modules (70) which switch part of the stator coils (12).

8. Cable car drive according to one of claims 1 to 7, characterized by an electrical braking device (66, 86, 88) which for exerting a braking force on the cable (28) or diε Stromrichtεr (70) of the electronic control unit (66 ) switches to braking operation and either conducts current induced in the stator coils (12) either via at least one Bre schoppεr (86) at least one braking resistor (88) or leads it back into the otherwise powering network (60).

9. Cable car drive according to einεm dεr claims 1 to 8, characterized in that the electronic control unit (66) is assigned εin Spεichεr (74) for mεhrεrε driving programs which can be selected selected.

10. Cable car drive according to εinε dεr claims 1 to 9, characterized gekennzεichnεt that the εelectronic control unit (66) is assigned a travel program memory (74) that a travel program with periodically higher cable speed and klεinεr Rope speed is included, the low rope speed being assigned to those times in which the transport units movable with the rope pass through sections of the route for boarding and alighting or loading and unloading.

11. Cable car drive according to one of claims 1 to

10, characterized by an electronic holding device (66), which controls the current in the stator coils (12) for a brief standstill of the cable (28) in such a way that the required holding torque is generated.

12. Cable car drive according to one of claims 1 to

11, characterized in that position sensors (80) are connected to the electronic step unit (66) on the stretch sections for getting in and out or loading and unloading the transport units movable with the rope (28), so that decelerations, stops , Slow travel, acceleration or the like depending on position sensor signals.