EP0542839B1 - Drive for an aerial cableway - Google Patents

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

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 with the release of an air gap, and an electrical control unit for timely switching of the Stator poles is provided.

So far, cable cars have been driven by 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 invention has for its object to make a cable car drive with a simple, configurable structure and much 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 rotor or the pulley relative to the stator. Hall sensors are particularly suitable for this. In terms of motor function, this drive can best be compared to a synchronous motor, 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 a substantially cylindrical or a substantially plane configuration, perpendicular to the axis of rotation or at an angle to this. 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 generally substantially annular 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 that only a partial circumferential area of the drive be occupied 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 stationary, 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 assigned to the internally toothed ring gear of a planetary gear instead of the 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 supporting part for the permanent magnets is preferably essentially cup-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 feeds the current induced in the stator coils either via at least one braking chopper to at least one braking resistor or into the otherwise supplying 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 in such a way that the drive generates a braking torque in the opposite direction to the drive torque in 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 supplying 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 works without wear. As a rule, there is also a mechanical brake system, in particular as a safety brake or as a parking brake. Feeding back into the power grid is particularly useful when the (evening) descent of the transport units can be moved with the rope.

The electronic control unit is preferably assigned a memory for a plurality of driving programs, which can be selected selected. 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, wherein 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 alighting 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 located in a section of the route for getting in and out or loading and unloading. 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 in and out 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 the transport of people or loads from a lower to a higher position, very particularly the various embodiments of lifts for the transport of skiers or hikers, such as pommel lifts, bow lifts, chair lifts, and cable cars. However, other transport systems in which a rope is to be driven can be equipped with the drive according to the invention, for example in mines with a vertical or inclined direction of movement of transport baskets.

It is pointed out that the preferred control configurations specified in claims 7 to 12 can also be implemented according to the invention in cable car drives which do not otherwise have the features of at least one of claims 1 to 6. An example is an electronically commutated permanent magnet electric motor for driving a cable car, which is otherwise 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.

Fig. 1

einen Seilbahnantrieb im Schnitt und teilweise weggebrochen;

Fig. 2

eine alternative Ausführungsform eines Seilbahnantriebs in schematisierter Darstellung, ebenfalls im Schnitt und teilweise weggebrochen;

Fig. 3

eine schematisierte Draufsicht auf einen Seilbahnantrieb ähnlich der Ausführungsform von Fig. 1 bei weggelassener Abdeckhaube;

Fig. 4

eine alternative Ausführungsform eines Seilbahnantriebs im Schnitt;

Fig. 5

Einzelheiten einer elektronischen Steuerung für einen Seilbahnantrieb.

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

Fig. 1

a cable car drive in section and partially broken away;

Fig. 2

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

Fig. 3

a schematic plan view of a cable car drive similar to the embodiment of Figure 1 with the cover removed.

Fig. 4

an alternative embodiment of a cable car drive in section;

Fig. 5

Details of an electronic control system 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 support part 4 can have an upper and a lower, circular plate or be designed with radial struts and a circular peripheral edge part. A generally annular stator 6 is fastened to the outer circumference of the supporting part 4. The stator 6 offers discrete pole faces 8 pointing radially outward. The individual ones Stator poles 10 are each wound with a coil 12.

A horizontal cable pulley 14 is arranged below the supporting 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 an annular distribution. The permanent magnets are attached to a radially outer magnetic return ring 22.

The permanent magnets 20 provide radially inward-facing permanent magnet pole faces 24. The stator pole faces 8 and the permanent magnet pole faces 24 face one another, with an essentially cylindrical air gap 26 with a radial width or thickness of approximately 2.5 mm existing between these pole faces 8, 24 .

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 downwards and the pole faces 24 of the permanent magnets 20 pointing upwards, 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 sheave 14, with a sensor on the supporting part 4, which will be explained in more detail later, the respective rotational position of the sheave 14 determines relative to the supporting part 4 and gives corresponding control signals to the control unit.

It is pointed out that the number of stator poles 10 and permanent magnet poles 24 preferably 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 main difference of the second embodiment of the cable car drive according to FIG. 2 compared to the first embodiment is that the stator 6 is not fastened to a support part fastened to the support column 2, but to annularly distributed supports 32 fastened to the ground the Variant shown that the stator 6 has both radially inward and radially outward facing stator pole faces and that permanent magnets 20 are fastened to the rotating pulley 14 both radially inside and radially outside of the stator. Finally, it can be seen that in this embodiment the cable tray 16 is provided radially outside the stator / permanent magnet arrangement.

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

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 assigned directly to the pulley 14, but rather to the internally toothed ring gear 36 of a planetary gear 38. An overall essentially ring-shaped stator 6 with discrete and wound with stator poles is attached to the outside of the circumference of the ring gear 36. The permanent magnets 20 sit radially outside 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. With the support member 39, the input shaft 44 of the planetary gear 38 is rotatably connected. 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 inside a vertical, stationary support column 52, which in turn is fastened on top of the plate 40 described earlier. 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 network 60 flows via a network feed 62 to a mains 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 a plurality of — in the illustrated example, six — converter modules 70, each of which switches a group of stator poles or stator coils. The signals of 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. With 82 an operating unit is designated, and 84 collectively designates 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 earlier.

External detectors 80 are, in particular, position sensors which provide 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 detect an overload, or emergency switches , for example in response to the failure of a cooling fan for the control electronics or to malfunctions 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.

With a brake chopper 86 is designated, which is connected to the power connection between the rectifier unit 64 and the control unit 66 (DC link). If the control unit 66 is given a "brake" command by hand or from the driving program, the converter modules 70 are controlled with the cooperation of the driving control 76 and the converter control 72 in such a way that current is supplied to the stator coils 12 at times such that the current direction 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 fed to the braking resistors 88 via the braking chopper 86 and / or 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 record the cable route covered by means of the control unit 66 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. If a specific target speed is specified by hand or through the drive programs, this is converted internally to a required drive torque. Apart from 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 cable car drive is preferably a unit which is mounted as a whole on foundations.

Claims (12)

1. A ropeway drive,
   characterized in
   that permanent magnets (20) of alternating polarity are disposed in annularly distributed manner on the driving pulley (14) of the ropeway;
   that opposite said permanent magnets (20) and with an air gap (26) being left free therefrom, there is provided a stationary annular stator (6) having stator poles (10) with windings;
   and in that an electronic control means (66) is provided for switching the stator poles (10) at the appropriate time.
2. A ropeway drive according to claim 1,
   characterized in that the pulley (14) is rotatably supported on a supporting pillar (2), and in that the stator (6) is disposed on a disc-like supporting member (4) connected to said pillar.
3. A ropeway drive according to claim 1,
   characterized in that the stator (6) is supported in stationary manner separately from the pulley (14).
4. A ropeway drive according to any 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. A ropeway drive according to any one of claims 1 to 4,
   characterized in that the stator (6) extends only over a partial circumferential portion such that a force of attraction results that is directed opposite to the rope pulling direction and relieves the support of the pulley (14).
6. A ropeway drive,
   characterized in
   that a planetary gear system (38) is connected to the driving pulley (14) of the ropeway;
   that an annular stator (6) having stator poles (10) with windings is provided on the stationary, internally toothed ring gear (36) of the planetary gear system (38);
   that the input shaft (44) of the planetary gear system (28) has connected thereto a supporting member (39) having annularly distributed permanent magnets (20) located opposite the stator poles (10) with an air gap (26) being left free therebetween;
   and in that an electronic control unit (66) is provided for switching the stator poles (10) at the appropriate time.
7. A ropeway drive according to any one of claims 1 to 6,
   characterized in that the electronic control unit (66) comprises a plurality of current converter modules (70) each switching part of the stator coils (12).
8. A ropeway drive according to any one of claims 1 to 7,
   characterized by an electrical brake means (66, 86, 88) which, for applying a braking force to the rope (28) or the current converters (70) of the electronic control unit (66), respectively, switches to braking mode and supplies the current induced in the stator coils (12) either via at least one braking chopper (86) to at least one braking resistor (88) or returns the same to otherwise feeding network (60).
9. A ropeway drive according to any one of claims 1 to 8,
   characterized in that the electronic control unit (66) has associated therewith a memory (74) for several travel programs which are selectively retrievable.
10. A ropeway drive according to any one of claims 1 to 9,
    characterized in that the electronic control unit (66) has a travel program memory (74) associated therewith which includes a travel program with periodically higher rope speed and low rope speed, with the low rope speed being associated with those times during which the transport units adapted to be moved by the rope travel through sections for boarding and unboarding or loading and unloading, respectively.
11. A ropeway drive according to any one of claims 1 to 10,
    characterized by an electronic hold means (66) which, for brief stopping of the rope (28), controls the current in the stator coils (12) such that the necessary holding moment is produced.
12. A ropeway drive according to any one of claims 1 to 11,
    characterized in that position sensors (80) are connected to the electronic control unit (66) in said sections for boarding and unboarding or, respectively, loading and unloading of the transport units adapted to be moved by the rope (28), such that deceleration, stopping, slow travel, acceleration or the like take place in response to position sensor signals.

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