Power transmission device for charging electrical energy storage devices of vehicles at overhead charging stations

Abstract

Vehicle-side current transmission device (4) for stationary charging of electrical energy storage devices of vehicles (7) at charging stations with current-supplying contact surfaces (13, 14, 15) arranged above the vehicle, with a charging current collector (4) which is designed to be multipole and has at least two electrically insulated contact elements (1, 2, 3) for stationary contacting of the current-supplying contact surfaces (13, 14, 15) which transmit different electrical phases, wherein all contact elements (1, 2, 3) are arranged next to each other on the common charging current collector (4) on an axis extending transversely to the direction of travel and are insulated from each other, characterized in that the charging current collector (4) is designed as an articulated arm system (4) and has at least one electrical contact element (1, 2, 3) which is designed as an earthing contact.

Description

[0001] The invention relates to a vehicle-side power transmission device for stationary charging of electrical energy storage devices of vehicles at charging stations with current-carrying contact surfaces arranged above the vehicle.

[0002] It is generally known from the state of the art that transport systems in which electrically powered vehicles are supplied with electrical energy via overhead lines are used. Particularly in local public transport, such vehicles are used either as trams or as trolleybuses. For the supply of power, a pantograph with electrical sliding contacts is in permanent sliding contact with the current-carrying wire stretched above the vehicle. Transport systems of this type require considerable investment in the transport infrastructure, especially with regard to the costs for the installation and maintenance of the overhead contact line system. Furthermore, unlike "free" road traffic, such a transport system is bound to a fixed, predetermined route. In addition to this rail or...Due to the track-bound nature of overhead lines, their appearance is often perceived as unaesthetic, especially in inner-city areas.

[0003] As electromobility progresses, these disadvantages could be overcome by using vehicles with rechargeable energy storage. However, these modes of transport require a charging infrastructure with charging stations where the batteries of electric vehicles can be charged at specific intervals. For public transport vehicles, these charging stations can be arranged as overhead charging stations, preferably in bus bays, so that charging can take place while the vehicle is stopped at a bus stop.

[0004] Secondly, in addition to the electric drive concept, the vehicles must be equipped with devices for power transmission, i.e., for electrically connecting the overhead charging stations and for discharging the charging current. Current collector systems known to date are designed almost exclusively for transmitting traction current, i.e., for supplying power while the vehicle is in motion, whereby the supplied electrical energy is converted directly into kinetic energy via an electric drive device without storage.

[0005] The invention disclosed in European patent application EP 2 380 767 A1 reveals a charging device for public transport vehicles equipped with electrical energy storage devices. However, this device is designed for a charging process that takes place while the vehicle passes a charging station. For this purpose, the vehicle and the charging station have a contact between the power rail and the guide rail, the length of which is dimensioned such that the contact duration is sufficient to transfer the necessary electrical energy while the vehicle passes at a specific speed.

[0006] A grounding arrangement for an inertial-driven vehicle is known from the generic patent application US 2,778,890 A. The arrangement has stationary charging contacts into which movable charging contacts of the vehicle engage. The charging contacts are arranged side by side transversely to the direction of travel above the vehicle; however, the ground connection is established via grounding contacts mounted laterally on the vehicle and separately arranged contact points. After the grounding contact is established, a voltage is applied to the charging contacts.

[0007] Document JP S53-11415A shows a charging current collector in which a charging current arrangement contacts a power supply unit by means of an articulated arm drive. To contact the load currents, a first charging current wheel and a second charging current wheel are pivoted laterally against opposing contact surfaces of a power supply unit. For grounding, a grounding wheel, arranged separately from the load current contact wheels, is also pivoted laterally against a contact surface of a grounding rail.

[0008] The design effort required for the known devices appears to be quite high.

[0009] The present invention is therefore based on the objective of developing a power transmission device for stationary charging of the electrical energy storage of an electric vehicle, in particular an electric vehicle for local public transport, which is as compact and lightweight as possible and which, in conjunction with simple positioning of the electric vehicle, enables quick and reliable electrical contact with the current-carrying contact surface of an overhead charging station. Furthermore, the device should be able to withstand high continuous mechanical loads.

[0010] This problem is solved in conjunction with the preamble of claim 1 by a charging current collector designed as an articulated arm system, which is multipole and has at least two electrically insulated contact elements for stationary contacting of the current-supplying contact surfaces, which transmit different electrical phases.

[0011] Since the roof of an electric vehicle, especially one equipped with additional components such as air conditioning for passenger transport, offers limited installation space for a current collector, a pantograph designed as an articulated arm system enables reliable connection and disconnection of the contact elements to / from the charging points of a charging station installed above the vehicle, all while requiring minimal space. Thanks to its articulated arm design, the pantograph forms a compact unit when retracted while driving, but can be quickly extended to the desired height when the vehicle stops at a charging station.

[0012] For stationary contacting of the current-carrying contact surface of a charging station running above the vehicle, at least two electrical contact elements are arranged on the charging current collector designed as an articulated arm system, so that via a single

[0013] Current collectors enable the phase contacts (voltage potentials) required for charging the electrical energy storage devices to be established with the respective contact surfaces of the charging station. Thus, the current transmission device according to the invention, for example, allows the positive and negative phases necessary for charging the electrical energy storage device to be contacted and conducted via a single current collector during DC charging.

[0014] In a preferred embodiment, the contact elements are arranged side-by-side on a common charging current collector, transverse to the direction of travel, and are insulated from one another. In this embodiment, all the different contact elements, i.e., both the phase contact elements and any grounding contact, are arranged side-by-side on a single, common charging current collector. The contact elements are therefore provided with insulation and sufficiently large insulating distances, the relative lateral distance of the contact elements to one another being determined by the arrangement of the current-carrying contact surface of the charging station and dimensioned to ensure fault-free contact, in particular to eliminate the risk of short circuits.

[0015] Advantageously, the trolley pole has at least one electrical contact element designed as a grounding contact. Since, unlike rail-bound vehicles, a trolleybus is largely insulated from earth potential by its rubber tires, a ground connection can be established via a grounding contact on the trolley pole and a corresponding grounding contact surface on the charging station. In this way, both the phase contacts and the grounding can be established via a single trolley pole.

[0016] In a further embodiment, the articulated arm system is designed as a single-arm system or as a multi-part scissor system and has a single base frame which is firmly connected to the vehicle and to which an articulated forearm of the articulated arm system is pivotably attached.

[0017] Such a articulated arm system is lightweight, which is advantageous for minimizing the overall vehicle weight during the numerous accelerations required, for example, in the regular operation of an electric bus. Furthermore, articulated arm designs are characterized by their simplicity and low maintenance requirements. The necessary stability is achieved by a single base frame, rigidly connected to the vehicle, to which a lower articulated arm of the system is pivotally attached.

[0018] A further advantage is that the contact elements extend sufficiently far to the direction of travel to allow the vehicle to be positioned under the charging station's current-carrying contact surfaces. The length of the contact elements, perpendicular to the direction of travel, is designed, taking into account the arrangement of the charging current contact surface, to provide the driver with sufficient positioning leeway to ensure reliable contact between the charging station and the vehicle's contact surfaces, even with slight track deviations, such as those caused by maneuvering around obstacles.

[0019] In a further preferred embodiment, the connecting cable(s) of the electrical contact element(s) are integrated into the articulated arm(s) in an electrically insulated manner. The charging current drawn via the contact elements is transmitted to the vehicle's electrical system electronics via connecting cables that run along the articulated arms in an electrically insulated manner.

[0020] Components of the articulated arm system and the base frame can also be designed as current-carrying conductors for connecting a contact element. In this configuration, electrically conductive parts of the pantograph itself form the connection line for a contact element.

[0021] The current flow from the other contact elements can be carried out via additional electrically insulated connecting cables laid on the articulated arms.

[0022] To ensure reliable contact, the individual contact elements can be movably arranged on the pantograph. This guarantees the necessary contact force of the individual contact elements against the current-carrying contact surfaces, even when manufacturing or assembly tolerances need to be compensated for, or when the vehicle is at a vertical angle.

[0023] Further advantageous design features will become apparent from the following description and the drawings, which illustrate a preferred embodiment of the invention by means of examples. They show: Fig. 1: A schematic representation of a charging current collector according to the invention in side view along the longitudinal axis of the vehicle and Fig. 2: a schematic representation of the charging current collector according to the invention in side view perpendicular to the longitudinal axis of the vehicle.

[0024] Fig. Figure 1 shows a schematic representation of the structure of the charging current collector 4 according to the invention. In the illustrated embodiment, the charging current collector is designed as a single-arm articulated arm system with an articulated arm 5. The articulated arm 5 is pivotably attached to a base frame 6, which in turn is fixedly mounted on the roof surface of an electric vehicle 7. In the retracted position, the articulated arm 5 rests on the base frame 6 parallel to the roof surface. At its end opposite the pivot bearing, three contact elements 1, 2, 3 are arranged side by side on the articulated arm 5 on an axis extending transversely to the direction of travel. By pivoting the articulated arm 5, the contact elements 1, 2, 3 can be brought into contact with current-carrying contact surfaces 13, 14, 15 of a charging station located above the vehicle 7. The term "current-carrying contact surfaces 13, 14, 15" is also understood here to include grounding contact surfaces for connection to earth potential.

[0025] In Fig. Figure 2 shows a schematic representation of the charging current collector 4 according to the invention, perpendicular to the longitudinal axis of the vehicle. The articulated arm 5 is in the extended position, so that the contact elements 1, 2, 3 of the charging current collector 4 touch the corresponding contact surfaces 13, 14, 15 of the charging station. The charging current flowing through the outer contact elements 13, 15 is diverted by insulated connecting lines 11, 12 attached to the articulated arm 5. A current flowing through the middle contact element 14 can be diverted via the electrically conductive articulated arm 5 itself.

[0026] To extend the contact elements 1, 2, 3, the pantograph 4 has a lifting drive 16, which is pneumatic, electric, hydraulic, or mechanical with a spring system, and to lower the contact elements 1, 2, 3, a lowering drive 17, which is also pneumatic, electric, hydraulic, or mechanical with a spring accumulator. The lowering of the contact elements 1, 2, 3 can also be achieved using gravity.

[0027] The present invention provides a current transmission device in the form of a charging current collector, enabling at least two or more electrical contacts to be established via a single collector. These contacts can transmit different electrical phases and simultaneously ground the vehicle. By designing the current transmission device as an articulated arm system, it can be realized in a particularly compact design with low weight. Such a vehicle-side charging device allows the driver to easily position the vehicle under the overhead charging station, ensuring reliable contact between the contact surfaces.The simple and robust design, combined with sophisticated lifting and lowering drives, is further characterized by low maintenance requirements and is able to withstand the large continuous mechanical loads that occur particularly in local public transport operations with a large number of lifting and lowering operations at the stops.

Claims

[1] Vehicle-side power transmission device (4) for stationary charging of electrical energy storage devices of vehicles (7) at charging stations with current-supplying contact surfaces (13, 14, 15) arranged above the vehicle, with a charging current collector (4) which is designed to be multi-pole and has at least two electrically insulated contact elements (1, 2, 3) for stationary contacting of the current-supplying contact surfaces (13, 14, 15) which transmit different electrical phases, wherein all contact elements (1, 2, 3) are arranged side by side on the common charging current collector (4) on an axis extending transversely to the direction of travel and are insulated from each other, characterized by , that the charging current collector (4) is designed as an articulated arm system (4) and has at least one electrical contact element (1, 2, 3) which is designed as an earthing contact. [2] Power transmission device according to claim 1, characterized by, that the articulated arm system (4) is designed as a single-arm system or as a multi-part scissor system and has a single base frame (6) which is rigidly connected to the vehicle (7) and to which an articulated forearm (5) of the articulated arm system (4) is pivotably attached. [3] Power transmission device according to claim 1 or 2, characterized by , that the extent of the contact elements (1, 2, 3) transverse to the direction of travel is sufficiently large to be able to position the vehicle (7) under the current-carrying contact surfaces (13, 14, 15) of the charging station. [4] Power transmission device according to any one of claims 1 to 3, characterized by , that a connecting line(s) (11, 12) of the electrical contact element(s) (1, 2, 3) is / are electrically insulated in the articulated arm(s) (5). [5] Power transmission device according to any one of claims 1 to 4, characterized by, that components of the articulated arm system (4) and the base frame (6) are designed as current-carrying conductors for connecting a contact element (1, 2, 3). [6] Power transmission device according to any one of claims 1 to 5, characterized by , that the individual contact elements (1, 2, 3) are movably arranged on the current collector (4) to ensure a secure contact. [7] Power transmission device according to any one of claims 1 to 6, characterized by , that the charging current collector (4) has a lifting drive (16) for extending the contact elements (1, 2, 3), which is pneumatic, electric, hydraulic or mechanical with a spring system. [8] Power transmission device according to any one of claims 1 to 7, characterized by, that the pantograph for lowering the contact elements (1, 2, 3) has a lowering drive (17) which is pneumatic, electric, hydraulic or mechanical with a spring accumulator or that the lowering of the contact elements (1, 2, 3) takes place by utilizing gravity.

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