Hoist with drive and method for operating a hoist

Abstract

Lifting device with drive, in particular wherein the drive makes a transport cell of the lifting device movable up or down along a rack arranged on a linkage, in particular modularly assembled, in particular wherein the drive is connected to the transport cell, wherein the drive comprises an electric motor which is supplied by an inverter which is supplied by a DC voltage, in particular an intermediate circuit voltage, and is controlled in particular by pulse width modulated control signals, where the direct current can be supplied from a power grid or alternatively from an energy storage device, where a means for detecting network failures controls a switching element which, in a first switch position, causes the provision of the DC voltage from the supply network and, in another switch position of the switching element, causes the provision of the DC voltage from the energy storage device, in particular directly or indirectly via a DC / DC converter arranged between the energy storage device and the DC voltage, so that - in the event of a power outage, especially a failure of the supply network, the DC voltage is supplied from the energy storage system for as long as necessary. until, during the controlled lowering of the transport cell after the power outage, the generator-generated electrical power is sufficiently large so that no further electrical power from the energy storage system is needed to supply the drive, in particular its signal electronics, - and in normal operation the direct current voltage is supplied from the mains supply network, wherein the supply network provides the DC voltage via a sliding contact, the sliding contact being arranged between the supply network and the DC voltage.

Description

[0001] The invention relates to a lifting mechanism with drive and a method for operating a lifting mechanism.

[0002] It is generally known that a lifting mechanism has an electric motor drive.

[0003] From DE 20 2014 009 760 U1 a rack and pinion elevator is known, wherein an energy storage device is arranged on the elevator car, from which the drive can be supplied in the event of a power failure.

[0004] WO 2007 / 112826 A1 discloses a conveying device in which the energy transfer to an elevator car is inductive and the transfer is described as using sliding contacts. Furthermore, an additional braking system is disclosed.

[0005] From DE 10 2012 016 700 A1 a method for intermediate storage of electrical energy in a lift system with energy storage is known, wherein the energy storage is connected to the intermediate circuit of the three-phase motor via a DC / DC converter.

[0006] From EP 1 272 418 B1, an emergency power supply unit for elevator systems is known.

[0007] A circuit arrangement is known from DE 10 2012 017 851 A1.

[0008] An elevator is known from JP 2009 - 62 178 A.

[0009] The invention is therefore based on the objective of further developing safety.

[0010] According to the invention, the problem is solved in the lifting mechanism according to the features specified in claim 1 and in the method according to the features specified in claim 5.

[0011] A key advantage is that in the event of a power outage, direct current can be supplied from the energy storage device, particularly a battery. The transport unit can then be lowered, thus providing the motor with regenerative power. This allows for controlled lowering and improves safety. The energy storage device only needs sufficient capacity to power the drive, including its signal electronics, after the power outage until the regenerative power is sufficient to eliminate the need for further power from the storage device. Therefore, a small energy storage device is sufficient, and a safety-related centrifugal brake can be omitted. This is particularly advantageous for construction hoists.

[0012] According to the invention, a means for detecting network failures controls a switching element which, in a first switch position, causes the provision of the DC voltage from the supply network and, in another switch position of the switching element, causes the provision of the DC voltage from the energy storage device, in particular directly or indirectly via a DC / DC converter arranged between the energy storage device and the DC voltage. in particular so that in the event of a power outage, especially in the event of a power outage, the DC voltage is supplied from the energy storage system and / or in normal operation the DC voltage is supplied from the power supply network.

[0013] The advantage here is that the power outage is detected and the supply is then switched to the energy storage system.

[0014] According to the invention, the supply network provides the direct current via a sliding contact, In particular, the sliding contact is arranged between the power supply network and the DC voltage. An advantage of this is that a sliding power supply can be used. Thus, a moving transport cell can be supplied with a contact-based power supply.

[0015] In an advantageous embodiment, the supply network powers a feed-in device, in particular an AC / AC converter, which induces a medium-frequency alternating current into a primary conductor, particularly one arranged on the linkage. A secondary winding, inductively coupled to the primary conductor and arranged on the transport cell, feeds an AC / DC converter that provides the DC voltage. An advantage of this design is that a contactless power supply is possible.

[0016] In a preferred embodiment, pulse-width modulated control signals from a signal electronics unit are fed to the inverter. An advantage of this is that the inverter enables speed control of the drive.

[0017] In an advantageous embodiment, the signal electronics supply a control signal to a brake, in particular a brake with brake control, which can be operated in opposition to the torque generated by the motor. It is advantageous that an additional brake can be used, thus further increasing safety. The brake is preferably designed as a centrifugal brake and / or a holding brake. With such a centrifugal brake, double safety is achieved, and with the holding brake, stopping without consuming electrical energy is possible. The holding brake is preferably designed as an electromagnetically actuated brake, wherein, when the coil of the electromagnet is not energized, spring elements press an armature disc against a brake pad carrier, which is rotationally fixed to the motor shaft but axially displaceable and which presses against a braking surface.

[0018] Key features of the method for operating a hoist are that a transport cell of the hoist can be raised or lowered by means of a drive along a linkage, in particular a modularly composed linkage, in particular wherein the drive is connected to the transport cell and thus movable along with it, where the drive is supplied with a direct current voltage, in particular intermediate circuit voltage, In normal operation, the direct current is supplied from a power grid, and in the event of a power failure, it is supplied or generated from an energy storage system.

[0019] The advantage here is that increased security can be achieved.

[0020] A further advantage is that in the event of a power outage, direct current can be supplied from the energy storage device, particularly a battery. The transport unit can then be lowered, thus providing the motor with regenerative power. This allows for controlled lowering and improves safety. The energy storage device only needs sufficient capacity to power the drive, including its signal electronics, after the power outage until the regenerative power is sufficient to eliminate the need for further power from the storage device. Therefore, a small energy storage device is sufficient, and a safety-related centrifugal brake can be omitted. This is particularly advantageous for construction hoists.

[0021] According to the invention, in the event of a power failure, a control signal causes a change in the switching state of a switching element, in particular a power semiconductor switch, In one switching state, the DC voltage is supplied from the mains, and in another switching state, the DC voltage is supplied from the energy storage device, either directly or via an intermediate DC / DC converter. An advantage of this is that electrically controllable switching is possible.

[0022] Further advantages arise from the sub-claims.

[0023] The invention will now be explained in more detail with the help of illustrations: In the Fig. Figure 1 shows a schematic sketch of a lifting device according to the invention. In the Fig. Figure 2 shows a schematic diagram of a circuit diagram according to the invention. In the Fig. Figure 3 shows a further schematic circuit diagram according to the invention.

[0024] As in the Fig. As shown in Figure 1, the transport system according to the invention has a modularly constructed linkage 10 with a rack, so that the transport cell 9 can be raised or lowered along the rack.

[0025] For electrical supply 1, either a conductor rail or a primary conductor is arranged parallel to the rack. The transport cell 9 thus receives its electrical supply via a contact shoe, which has electrical contact with the conductor rail, or alternatively via a secondary winding that is inductively coupled to the primary conductor but located at the transport cell 9. A capacitor is connected in parallel and / or in series with the secondary winding such that the resonant frequency of the resulting resonant circuit essentially corresponds to the medium-frequency alternating current impressed into the primary conductor. This enables highly efficient inductive energy transfer.

[0026] In this way, an electrical power supply network or an inductive power source is provided for the transport cell 9, which also has its own drive. For this purpose, a gearbox 30 is arranged in the transport cell, which can be driven by an electric motor 7. By means of an intermediate brake 8, it is possible to brake the drive shaft of the gearbox 30, and thus also the rotor shaft of the electric motor 7, which is non-rotatably connected to this drive shaft.

[0027] The electric motor 7 is powered by a frequency converter 6, which can be supplied with DC voltage from a DC link, which can also be supplied from the energy storage device 5. The converter 6 includes an inverter, which can be supplied from the DC link and receives control signals from the converter 6's signal electronics. The output voltage provided by the inverter is used to power the motor 7, thus allowing its speed to be controlled.

[0028] In Fig. 2. The power supply 1 of the inverter 6 is provided by a DC voltage. The inverter of the inverter 6, which provides a three-phase voltage system to the motor 7, can be supplied by this DC voltage. The DC voltage is also referred to as the intermediate circuit. The intermediate circuit can also be supplied by an AC voltage, if one is provided, if a rectifier is used. For example, an AC voltage can be supplied to the transport cell 9 via the loop supply instead of a DC voltage. This AC voltage can then be converted into a DC voltage by the aforementioned rectifier, which is then fed into the intermediate circuit.

[0029] As in Fig. As shown in Figure 2, a coupling element, such as a diode, can be provided between the energy storage device 5 and the intermediate circuit. Thus, the energy storage device can be charged when the intermediate circuit voltage is above the charging voltage of the energy storage device 5. This is the case during normal operation. This is because, during normal operation, the electrical supply 1 is present, and sufficient energy is supplied to the intermediate circuit so that the intermediate circuit voltage corresponds to its nominal value during operation.

[0030] If the electrical supply 1 fails, the DC link voltage drops. As soon as the charging voltage of the energy storage device 5 is higher than the DC link voltage, the DC link is supplied from the energy storage device 5 by actuating the switching element 3 accordingly, thus enabling the current supply from the energy storage device 5 to the DC link.

[0031] Similarly, the DC / DC converter 32 in the embodiment according to the invention is also Fig. 3 is controllable. In the event of a power failure, the switching element 3 is controlled accordingly by means of the control signal 2. Thus, when a power failure occurs, the energy storage device 33 supplies the intermediate circuit, i.e., the DC-side supply of the inverter of the converter 6, via the DC / DC converter 32. In normal operation, the energy storage device 33 is charged from the intermediate circuit. If the DC / DC converter 32 is bidirectional, charging can be carried out via the DC / DC converter 32. Alternatively, charging can also be carried out via a diode, whereby the maximum permissible charging voltage of the energy storage device 33 must match the intermediate circuit voltage.

[0032] As in Fig. As shown in Figure 3, a DC / DC converter 32 can be connected between the inverter 6 and the energy storage device 5, allowing the voltage level to be adjusted. The energy storage device 5 is therefore connected to the DC link of the inverter 6 either directly or indirectly via the DC / DC converter 32.

[0033] The brake 8 is controlled via a control signal generated by the brake control 31, which in turn is controlled by the inverter 6, in particular by its signal electronics.

[0034] As in Fig. As shown in Figure 3, the inverter 6 can then be supplied from the energy storage device 33 via the DC / DC converter 32 if a corresponding control signal is supplied from the signal electronics of the inverter 6 to the DC / DC converter 32 via a switching element 3.

[0035] Advantageously, in the event of a power failure, there is no rapid stop due to a centrifugal brake of the drive, but rather the safety-oriented lowering of the transport cell 9 can be carried out in a controlled manner. Reference symbol list 1 electrical supply, in particular electrical supply network or inductive supply source 2 Control signal for switching element 3 3 switching element 4 Coupling element, in particular diode 5 Energy storage devices, especially energy storage devices with DC / DC converters 6 inverters 7 Electric motor 8 Brake 9 Transport cell 10 linkages with rack and pinion 30 gearboxes 31 Brake control 32 DC / DC converters 33 Energy storage

Claims

[1] Lifting mechanism with drive, in particular wherein the drive makes a transport cell of the lifting mechanism movable up or down along a rack arranged on a linkage, in particular modularly assembled, in particular wherein the drive is connected to the transport cell, wherein the drive comprises an electric motor which is supplied by an inverter which is supplied by a DC voltage, in particular an intermediate circuit voltage, and is controlled in particular by pulse width modulated control signals, where the direct current can be supplied from a power grid or alternatively from an energy storage device, where a means for detecting network failures controls a switching element which, in a first switch position, causes the provision of the DC voltage from the supply network and, in another switch position of the switching element, causes the provision of the DC voltage from the energy storage device, in particular directly or indirectly via a DC / DC converter arranged between the energy storage device and the DC voltage, so that - in the event of a power outage, especially a failure of the supply network, the DC voltage is supplied from the energy storage system for as long as necessary. until, during the controlled lowering of the transport cell after the power outage, the generator-generated electrical power is sufficiently large so that no further electrical power from the energy storage system is needed to supply the drive, in particular its signal electronics, - and in normal operation the direct current voltage is supplied from the mains supply network, wherein the supply network provides the DC voltage via a sliding contact, the sliding contact being arranged between the supply network and the DC voltage. [2] Lifting device according to claim 1, characterized by , that the supply network supplies a feed-in device, in particular an AC / AC converter, which induces a medium-frequency alternating current into a primary conductor, in particular arranged on the linkage, wherein a secondary winding inductively coupled to the primary conductor and arranged on the transport cell feeds an AC / DC converter, which provides the DC voltage. [3] Lifting device according to at least one of the preceding claims, characterized by , that pulse-width modulated control signals from a signal electronics unit are supplied to the inverter. [4] Lifting device according to at least one of the preceding claims, characterized by , that the signal electronics supply a control signal to a brake, in particular a brake with brake control, which can be operated in opposition to the torque generated by the motor. [5] Method for operating a lifting device, in particular a construction hoist, wherein a transport cell of the lifting mechanism can be raised or lowered by means of a drive along a linkage, in particular a modularly composed linkage, in particular wherein the drive is connected to the transport cell and thus movable along with it, where the drive is supplied with a direct current voltage, in particular intermediate circuit voltage, in normal operation the DC voltage is supplied from a power grid and in the event of a power failure it is supplied or generated from an energy storage system, until, during the controlled lowering of the transport cell after the power outage, the generator-generated electrical power is sufficiently large so that no further electrical power from the energy storage system is needed to supply the drive, in particular its signal electronics, wherein, in the event of a power failure, a control signal causes a change in the switching state of a switching element, in particular a power semiconductor switch, wherein in one of the switching states the DC voltage is supplied from the grid and in another switching state the DC voltage is supplied from the energy storage directly or via an intermediate DC / DC converter.

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