Overhead line system for construction machinery for the transport of pieces and bulk materials as well as construction machinery

Description

[0001] The invention relates to an overhead line system for the electrical supply of the drive system of one or more construction machines for the transport of piece goods and bulk materials, wherein the overhead line comprises at least one pair of lines running parallel along the route and carrying current of opposite polarity, which can be electrically contacted by corresponding current collectors of at least one construction machine.

[0002] Electrification of construction machinery for handling piece and bulk materials is becoming an increasingly relevant topic, especially in mining and open-pit mining, where consistent transport routes are traveled with the highest possible frequency. In particular, the dump trucks used in these areas with the highest load volumes, i.e., 100 tons and more, are predominantly equipped with diesel-electric drives, in which an internal combustion engine drives the integrated generator, which in turn supplies the electrical energy for the electric drive motors.

[0003] In open-cast mining, dump trucks travel long, straight routes from the loading point to their destination. To reduce diesel consumption and CO2 emissions of the vehicle fleet, the straight section of the route is equipped with an overhead line system for the vehicles. The vehicles themselves can use their installed pantographs to capture the energy needed to power their electric traction motors in this section. In addition to the significant savings in diesel consumption, an optional increase in performance and a reduction in travel time can also be achieved. DE 10 2011 076623 A1 and EP 1 086 845 A1 disclose a system comprising an overhead line system and a vehicle with pantographs according to the state of the art.

[0004] Due to the predominantly straight route, pantographs are used as current collectors, as they allow for simple and quick mechanical contact with the overhead line, even during movement. A disadvantage of this technology, however, is that this type of current collector requires a straight route and is therefore unsuitable for routes with tight curves, as is often the case in mining with its winding mountain roads.

[0005] Recently, however, there has been a desire to provide a suitable external power supply for the dump trucks used there. The task of this application therefore concerns the development of a suitable overhead line system for curved track layouts, as well as construction machinery with suitable pantographs.

[0006] This object is achieved by a system according to the features of claim 1. Advantageous embodiments of the system are the subject of the dependent claims.

[0007] According to the invention, it is proposed to provide an overhead line system for construction machinery with current collectors, each having a rod with a current collector head at its end for contacting an individual line. The current collector heads can be equipped with a contact shoe, a roller, or similar and are pressed onto the line from below and guided by the contact shoe, the roller, etc. For example, such a contact shoe comprises a half groove / rounding, which is brought into contact with the round power line / cable. The aforementioned current collector type is also suitable for curved overhead lines. However, the mechanical connection requires precise alignment of the current collector heads to the assigned overhead line during the connection phase, which necessitates exact positioning of the construction machinery below the overhead line during this connection phase.This has so far been difficult to achieve during operation, so the vehicles are currently stopped below the overhead line to allow the pantographs to be aligned with the overhead line at leisure. However, the resulting forced stop lengthens the cycle time for a loading and unloading process, which is neither desirable nor acceptable from an economic perspective given the relatively high investment in the vehicle fleet. Furthermore, every braking and acceleration process during mining operations impairs the efficiency of the entire mining process. In addition to the resulting increased stress on the track and vehicle tires, the overall energy requirement also increases.

[0008] Against this background, the invention proposes providing the parallel lines carrying opposite potentials with suitable guides that support and greatly simplify the precise positioning and alignment of the pantographs to the overhead line. Ideally, this enables easy contact even while the construction machine is moving.

[0009] The walls of the guide aid form a feed channel that is open at the bottom and extends from the front end of the guide aid to the opposite end of the guide aid with the cable connected there. The cable can, for example, be guided above the guide aid in the area of ​​the feed channel and is only guided downwards again in the end area of ​​the guide channel to enable contact with the current collector. The head of the current collector inserted into the feed channel is guided inside the feed channel in the direction of travel to the cable connected at the end of the feed channel. The shape of the channel becomes narrower or converges in the direction of travel towards the adjoining overhead line, i.e. the cross-sectional profile of the feed channel reduces in the direction of the overhead line. The initially large channel width of the guide aid simplifies the insertion of the corresponding current collector head into the feed channel.The channel shape, which becomes narrower in the direction of travel, ensures the exact alignment of the current collector head to the adjoining overhead line, so that the collector shoe, roller or other contact means of the current collector head runs along the underside of the line after exiting the feed channel of the guide aid.

[0010] According to a preferred embodiment, the guide aid(s) have an outward widening of the feed channel width, i.e., directed toward the adjacent pair of lines. In particular, a side wall of the guide aid is provided that runs parallel to the line, while the opposite wall is oriented from the outside toward the line, thereby creating the desired reduction in the channel width in the line direction. Such a design has the advantage that the shape of the guide aid does not obstruct the adjacent pair of lines, so that the overhead line can be routed continuously with a constant line spacing.

[0011] However, it is also conceivable that the channel width is widened symmetrically to the central axis of the guide aids and converges in the direction of the line to the central axis of the guide aid.

[0012] According to an advantageous embodiment, the guide means for the parallel lines can be arranged offset from one another in the direction of travel. This offset arrangement enables a delayed mechanical and electrical contact between the current collector heads of the construction machine and the overhead line. Ideally, the guide means for the positive-potential line is arranged after the guide means for the negative-potential line in the direction of travel, so that an electrical connection to the negative potential is initially established.

[0013] It is also possible for the guide rails of a pair of lines to be arranged next to each other at the same height, as seen in the direction of travel. In such a design, it can optionally be provided that the distance between the center axes of both guide rails is greater than the distance between the overhead line pair.

[0014] According to an advantageous embodiment, the channel width of the guide aid decreases from its frontal channel opening toward the adjacent overhead line. The larger the channel opening width, the greater the lateral deviation of the current collector head's alignment relative to the line run can be. Ideally, in addition to this, but also alternatively, the channel height can converge toward the beginning of the line. Ideally, the channel of the guide aid exhibits a conical shape in the axial direction, i.e., in the direction of travel. The guide aid or channel is open on its underside, i.e., the side facing the ground, for the pole rods of the current collector head.

[0015] The distance between the two lines of the overhead line system generally runs parallel and at a nearly constant distance over the entire route. However, according to a particularly advantageous embodiment of the invention, the distance between the two lines can be increased in the area of ​​a guide rail, thereby allowing space for dimensioning the guide rail transversely to the direction of travel. This enables the guide rail to be designed with the largest possible channel width; in particular, the initial channel width is greater than the regular distance between the pair of lines.

[0016] Preferably, in order to increase the distance, the first line running parallel to the guide aid of the second line can be deflected laterally outwards and redirected in the direction of travel after the guide aid in order to reduce the distance back to the normal level.

[0017] To assist the driver of the construction machine during positioning for overhead line operation, the running surface can be provided with one or more visual markings in the area below or just in front of at least one guidance aid. A suitable example is a corresponding visual guidance system that informs the driver at an early stage of the required alignment and positioning of the construction machine below the overhead line system. In its simplest form, such a system can comprise one or more graphic markings applied to the running surface. It is also conceivable to use optical projections onto the running surface instead. The use of suitable lighting to create a beacon known from maritime applications is also conceivable.Light sources, particularly LEDs, generate one or more colored light areas to mark a desired driving path for the construction machine. Such a system can also assist the driver while driving, keeping the vehicle as close to the power lines as possible. This can also be done by displaying the vehicle's position relative to the power line on a screen. If necessary, the maximum permissible lateral deviations can be highlighted visually or acoustically. This can also contribute to autonomous driving / steering control.

[0018] In addition to the overhead line system according to the invention, the present invention relates to a construction machine, in particular a construction machine for mining and / or open-cast mining, which is characterized by an electric travel drive. According to the invention, such a construction machine, in contrast to previously known vehicles, has current collectors with at least two separate current collector heads. According to the invention, these current collectors can be actively moved in the vertical as well as in the horizontal direction, i.e. transversely to the direction of travel, by means of suitable drives. Ideally, the individual current collectors can be adjusted independently of one another in both the vertical and horizontal directions. Such a construction machine is therefore suitable for overhead line operation with a curved line course. In particular, such a construction machine is suitable for operation with an overhead line system according to the present invention.In addition to the active adjustment option, a passive adjustment in the vertical and / or horizontal direction is also possible, preferably by applying force to the overhead line system.

[0019] The pantographs are pressed against the overhead line while the vehicle is moving. A suitable system can be provided for this purpose, ensuring automatic compensation for horizontal and / or vertical vehicle movements relative to the power lines, for example, caused by steering movements and / or uneven road surfaces. A mechanical system, optionally supported hydraulically and / or electrically, is conceivable.

[0020] In an advantageous embodiment of the construction machine, it is designed as a dump truck with an erectable trough for receiving piece or bulk material. The picked-up piece or bulk material and the trough's erection mechanism impair the roof-side (on the top of the vehicle) mounting of the pantographs. Instead, according to an advantageous embodiment, the pantographs, in particular the pole rods with the end heads, in particular the contact shoes, are mounted in an articulated manner on the front of the vehicle. The articulated connection allows the pole rods to be erected for overhead line operation. For autonomous operation of the construction machine, the pole rods can be lowered and placed on the vehicle, in particular adjusted around a horizontal axis transverse to the direction of travel.By providing an additional degree of freedom of the pole rods around an axis in the direction of travel, certain transverse deviations of the vehicle position relative to the longitudinal direction of the overhead line can be compensated, since the pole rods can then be actively and passively tilted to the right or left, for example, as seen in the direction of travel.

[0021] It is also advantageous to position the poles on the construction machine offset to the side of the driver's cab, so that the poles do not obstruct the driver's field of vision. Ideally, the poles are offset from the driver's cab on the side of the roadway. This provides the best visibility for the driver, and the power line can be installed with a short overhang from the power line supports.

[0022] For the articulated connection of the poles, a support frame is preferably constructed, which is preferably rigidly mounted on the front of the vehicle and includes a receiving platform for the articulated connection of the poles. According to a preferred embodiment, the support frame consists of several support rods. Ideally, at least two support rods are mounted on the front lower edge of the vehicle frame, while at least two support rods are attached to the upper edge, for example, on the platform of the dump truck. The support rods extend diagonally upwards from the front of the vehicle. The free ends of the support rods preferably converge to form the common receiving platform for the poles.

[0023] Furthermore, the construction machine can be provided with a canopy in the area of ​​the front of the vehicle. In accordance with the usual design of dump trucks, the trough projects over a vehicle platform in the area of ​​the front of the vehicle. Since it is desirable to lower the current collector heads below the canopy, the canopy can be provided with a corresponding recess at this point. In particular, the current collector heads can be lowered onto a receiving device located below the canopy. One advantage of this design is that it allows the ratio between vehicle length and pole rod length to be optimized. The recess in the trough also enables a shorter vehicle design, which, in conjunction with the ability to adjust the current collectors, makes it possible to travel on tight radii.

[0024] By lowering the current collector heads beneath a canopy, they are protected from environmental influences. Furthermore, storing the current collector heads improves ease of maintenance, as they are easily accessible via the vehicle platform for maintenance and repair purposes. Current collector heads are often equipped with wear parts that require regular replacement. These include the contact pads.

[0025] It is advantageous to modify the canopy in the area of ​​the recess, in particular with a raised edge threshold, in order to prevent piece goods and bulk goods from rolling over the edge of the recess and the stones from falling onto the pantographs below.

[0026] To transition to overhead line operation, the poles of the construction machine must first be erected, although in the case of the overhead line system according to the invention this can also be delayed. Ideally, the construction machine comprises a suitable control unit that triggers automatic erection of the poles as soon as the construction machine assumes a corresponding position below the overhead line or the driver issues a manual control command. The same preferably applies when transitioning from overhead line operation to autonomous operation. Likewise, the control unit can automatically carry out a horizontal displacement of the current collector heads for the correct alignment with the overhead line during the transition to electric operation or afterwards during electric operation. While traveling along the power line, there is preferably no active adjustment of the current collectors in the horizontal and / or vertical direction.Instead, only a passive connection is made through contact pressure.

[0027] It is conceivable that one or more mirrors and / or cameras are provided on the construction machine to allow the driver to check that the pantographs are properly contacted with the overhead line.

[0028] It is also conceivable for the construction machine to be equipped with a visual system to support the driver during the process of connecting the pantograph to the overhead line and / or during operation in overhead line mode. The latter also supports the driver while driving, ensuring the vehicle travels as far below the power line as possible. This could be achieved, for example, by displaying the position of the vehicle relative to the power line on a screen on the construction machine. If necessary, the permissible maximum lateral deviations could be highlighted visually or acoustically. Implementing autonomous driving / steering control in overhead line operation is also conceivable.

[0029] In addition to operating the actuators for the pantographs, the control unit also controls the construction machine's internal power electronics to switch the electrical supply to the drive motors from the internal source to the external supply via the overhead line. The same optionally applies to any recuperation mode of the vehicle.

[0030] It is particularly advantageous if the construction machine is designed as a dump truck with a loading volume of approximately 50 to 200 t, preferably between 80 t and 150 t, ideally approximately 100 t.

[0031] The invention also encompasses an overall system consisting of an overhead line system, in particular according to the aforementioned invention, and at least one construction machine according to the above statements. The active adjustment capability of the current collector rods or current collector heads in both vertical and horizontal directions enables universal application for a wide variety of overhead line systems.

[0032] Finally, the invention also encompasses the specific use of the aforementioned complete system for supplying at least one construction machine with electrical energy on a mountain road. The system demonstrates its full strengths particularly on mountain roads with tight curves.

[0033] Further advantages and features of the invention will be explained in more detail below using an exemplary embodiment shown in the figures. They show: Fig. 1: a perspective side view of the dump truck according to the invention with a part of the novel overhead line, Fig. 2: a side view of the dump truck according to Fig. 1 , Fig. 3a: a top view of the dump truck according to Figures 1 , 2 , Fig. 3b: a plan view of the overhead line according to a modified variant, Fig. 4: a rear view of the dump truck according to the Figures 1 to 3, Fig. 5a: the flow block diagram during the switching of the construction machine from diesel-electric drive to overhead line operation in an overhead line system with offset guide aids, Fig. 5b: the flow block diagram during the switching of the construction machine from diesel-electric drive to overhead line operation in an overhead line system with parallel guide aids, Fig. 6a to 6e: different block diagrams to illustrate the power flow of the dump truck during its different operating modes, Fig. 7: another embodiment of the overhead line with the dump truck according to the invention and Fig. 8: the embodiment according to Fig. 7 in a plan view, Fig. 9: a side view of the embodiment according to the Figures 7, 8 and Fig. 10: a further modification of the overhead line system.

[0034] The Figures 1 to 4show sketches of the dump truck according to the invention, the drive of which is essentially based on a diesel-electric principle. The installed diesel unit drives a power generator which feeds the at least two electric motors on the rear axle of the dump truck. The vehicle's hydraulics, for example for raising and lowering the dump body 1, are connected to the output of the diesel engine via a branch gear. The dump truck shown belongs to the category of so-called small or midsize trucks with an average loading volume of 100t. At the front of the vehicle, above the radiator 2, there is a vehicle platform 3 on which, among other things, the driver's cab 5 is located. A flat surface 4 of the dump body projects over the platform 3 in the form of a canopy 4.

[0035] The vehicle shown is intended primarily for use in mining on winding mountain roads, where there is a desire for an optional external electrical supply for the electric traction drive via an overhead line. For power collection for overhead line operation, the dump truck includes current collectors 10 with two pole rods 11a, 11b. At their free ends or current collector heads, contact shoes 12a, 12b are provided for mechanical contact with the parallel power lines 21a, 21b of the overhead line system 20. The contact shoes typically include a replaceable carbon contact strip. The contact shoes 12a, 12b each comprise a half groove / rounded portion, which is pressed onto the lines 21a, 21b from below via the pole rods 11a, 11b.After successful mechanical contact with the lines 21a, 21b, the electrical energy of the overhead line for supplying the internal drive of the dump truck can be tapped via the electrical connecting line of the pole rods 11a, 11b.

[0036] During autonomous operation of the dump truck without power from the overhead line 20, the pole rods 11a, 11b, or the current collector heads 12a, 12b, are placed on a support device 16 below the canopy 4 in the area of ​​the platform 3. The necessary articulated connection of the pole rods 11a, 11b to the front of the dump truck is achieved by means of a support structure 13 consisting of four support rods 13a-13d, two of which are mounted on the lower edge 6 of the vehicle frame, and two further support rods 13c, 13d are mounted on the platform 3. The support rods extend diagonally upwards from the front of the vehicle and converge at their ends. Cross struts 13 connecting the support rods 13a-13d increase the stability of the support structure 13.The pole rods 11a, 11b are articulated on a support platform 15 provided at the converging end of the support rods 13a-13d. They can pivot about a horizontal axis perpendicular to the direction of travel and optionally about a horizontal axis parallel to the direction of travel. An integrated actuator system allows the controlled raising and lowering of the pole rods 11a, 11b to switch the dump truck between diesel-electric operation and overhead line operation. At the same time, the pole rods can also be actively pivoted laterally about the horizontal axis parallel to the direction of travel by means of a drive. The pantographs 10 are generally only actively moved by the corresponding drives during the connection process. While traveling along the power line 20, there is preferably no active adjustment of the pantographs 10 in the horizontal and / or vertical direction.However, the pantographs 10 are pressed more or less constantly against the overhead line during overhead line operation. This also requires automatic compensation for horizontal and / or vertical vehicle movements. A mechanical system can be provided for this purpose, optionally with hydraulic and / or electrical support.

[0037] This is particularly evident in Fig. 3 that the current collector heads 12a, 12b of the pole rods 11a, 11b, placed on the receiving device 16, are at least partially protected under the canopy 4 of the trough 1. However, a recess 4a is cut into the canopy 4 for raising and lowering the pole rods 11a, 11b. The raised edge 17 of the canopy 4 prevents bulk material from rolling over the canopy 4 onto the current collectors 11a, 11b below.

[0038] By using the pantographs 10, the dump truck can also be used on curved overhead lines, such as those required on tight mountain roads in mining. To ensure a smooth transition to overhead line operation, ideally without having to stop the dump truck to connect the pantographs 10 to the overhead line 20, the overhead line 20 is equipped with suitable guides 22a, 22b.

[0039] The overhead line comprises a line 21a with negative potential and an overhead line 21b with positive potential. At the beginning of each line, the guide aids 22a, 22b are arranged, consisting of two triangular side walls 23 and a triangular top 24 to form a box structure. The guide aids 22a, 22b are open at the front and bottom. The walls 23, 24 form the feed channel, which narrows from the front channel opening 25 toward the beginning of the line, i.e., both the channel width and the channel height decrease in the direction of travel.

[0040] The unfolded or upwardly extended current collector pole 11a, 11b is now inserted with its head or contact shoe 12a, 12b into the guide aid 22a, 22b from the front or from below during the travel movement. Due to the side surfaces 23, 24 converging toward the line, the current collector head 12a, 12b is guided over the side surfaces until it precisely contacts the line 21a, 21b and is thus optimally positioned. The contacting of the current collectors 10 is initially mechanical (pressing) and then electrical.

[0041] In the embodiment of the Figures 1 to 4As shown in Figures 3a and 3b, the guide aids 22a, 22b are also arranged offset one behind the other in the direction of travel, with the guide aid 22a of the negative potential line 21a being arranged first, and the guide aid 22b of the positive potential line 21b following in a staggered manner. As a result, the poles of the current collector 10 of the dump truck are temporarily delayed in connecting to the overhead line 20, i.e., the negative potential is contacted first, followed by the positive potential.

[0042] A further advantage of this axial offset of the guide aids 22a, 22b in the overhead line direction is that they can be made wider without interfering with each other. The width, i.e., the width of the upper side 24, is also selected to be larger than the actual distance d 1 between the lines 21a, 21b (see Figure 3). However, for this purpose, the section of the cable 21a running parallel to the downstream guide aid 22b must be deflected laterally in order to avoid contact with the guide aid 22b.

[0043] In the embodiment of the Figures 1 , 2 , 3 , 4 Both side walls 23 run from the outside to the inside, so that the channel width is reduced symmetrically in the longitudinal direction of the guide aids 22a, 22b. A modified version of the guide aids 22a, 22b is shown in Figure 3bThere, the inner side walls 23a run parallel to the overhead line 21a, 21b; only the outer side walls 23b are arranged at an angle to the overhead line axis and run longitudinally from the outside inward toward the overhead line 21a, 21b. The channel width of the guide aid 22a, 22b is therefore only increased outwardly, so that the distance between the overhead lines 21a, 21b can remain unchanged even in the area of ​​the guide aids 22a, 22b.

[0044] The basic process during the transition from diesel-electric drive mode to overhead line operation is shown in the flow chart of the Figure 5aIn the first step, the dump truck is initially driven using diesel-electric propulsion. Shortly before reaching the starting point of the overhead line 20, the pole rod 11a for the negative potential is raised and brought into mechanical connection with the negative overhead line 21a via the first guide aid 22a. If necessary, the pole rod 11a is also actively pivoted around the pivot axis running parallel to the overhead line 21a using the corresponding drive to facilitate insertion into the guide aid 22a.

[0045] Once mechanical contact has been established between the negative current pole 11a and the corresponding overhead line 21a, the pole rod 11b for the positive potential is raised and brought into contact with the corresponding overhead line 21b using the second guide aid 22b. Here, too, actively pivoting the pole rod 11b about the pivot axis running parallel to the overhead line 21b can be helpful. Subsequently, the power electronics of the dump truck switches the vehicle's operation from diesel-electric drive to overhead line operation by actuating the corresponding power switch(es), which ultimately allows the vehicle to operate in overhead line operation.

[0046] The inventive design of the dump truck with current collectors 10, whose poles 11a, 11b can be actively displaced both vertically and horizontally, allows the dump truck to be used for different overhead line systems. An alternative to the variant of the Figures 1 to 4 is in the Figures 7 to 9 The dump truck shown there is identical to the version in the Figures 1 to 4 The only difference is the arrangement of the guide aids 22a, 22b of the overhead line system 20, which are Figures 7 to 9 are no longer offset, but are placed directly next to each other at the beginning of the overhead line 20.

[0047] In particular, the top view of the Figure 8 It can be seen that for such an arrangement the distance between the lines 21a, 21b at the beginning of the overhead line, in Figure 8marked as section a, must be significantly larger in order to be able to realize the largest possible channel opening of the guide aids 22a, 22b in this embodiment as well. Since the distance between the pole rods 11a, 11b is usually adapted to the standard distance of the overhead line 20, the pole rods 11a, 11b must be actively pivoted outwards around the pivot axis of the pole rod bearing, which runs parallel to the line 21a, 21b, before being inserted into the guide aids 22a, 22b or before contacting the lines 21a, 21b. Figures 7 to 9 The position of the pole rods 11a, 11b is shown to be tilted by about 10 degrees. Contrary to the design in the Figures 1 to 4 The pole rods are dynamically aligned during the journey and simultaneously connected to the respective overhead lines 21a, 21b.

[0048] The corresponding counterpart to the modification of the Figure 3b is in Figure 10In the design of the guide aids 22a, 22b shown there, only the outer side wall 23b runs from the outside to the inside, while the inner side wall 23a runs parallel to the overhead line 21a, 21b. As in the design of the Figures 7 to 9 Here, the guide rails 22a, 22b are arranged parallel to one another. However, since the channel only widens outward, the distance between the overhead lines 21a, 21b can remain constant along their entire length, at least in the area of ​​the guide rails 22a, 22b.

[0049] The basic procedure during the transition from diesel-electric drive mode to overhead line operation when the overhead line system is designed according to the Figures 7 to 10 until according to Figure 10 is the flow chart of the Figure 5bIn the first step, the dump truck is initially driven using diesel-electric propulsion. Shortly before reaching the starting point of the overhead line 20, both pole rods 11a, 11b are raised simultaneously and brought into mechanical connection with the overhead line pair 21a, 21b via assigned guide aids 22a, 22b. If necessary, the pole rods 11a, 11b are also actively pivoted about the pivot axis running parallel to the overhead line 21a, 21b using the corresponding drive to facilitate insertion into the guide aid 22a, 22b. After confirmation of proper mechanical contact, the electrical connection between the overhead line with negative potential and the vehicle electronics is first established. The electrical connection with the positive potential then takes place a short time later.The dump truck's power electronics then switch the vehicle's operation from diesel-electric drive to overhead line operation by operating the corresponding power switch(es), which ultimately allows the vehicle to run in overhead line operation.

[0050] The corresponding power flow during the different operating conditions of the dump truck is shown in the Figures 6a to 6c marked. The Figure 6a shows the regular diesel-electric driving operation, during which the diesel unit drives both the hydraulic pumps and the generator, the latter feeding the electric drive motors when the power electronics are switched on accordingly.

[0051] When braking the vehicle in diesel-electric mode, the braking effect is achieved not only by a conventional mechanical brake but also by the electric drive motors operating in generator mode. The recovered generator energy is fed back to the actual generator via the power electronics, which acts as an electric motor to drive the motor shaft and / or the hydraulics (see Figure 6b ).

[0052] Figure 6cThe diagram now shows the vehicle's operation via the overhead line supply. Via the pantographs 10 and the corresponding control unit, which automatically actuates the pantograph poles 11a, 11b, the electrical energy is supplied by the power electronics to both the electric drive motors and the generator. During engine operation, the generator also supports the hydraulic pump or diesel generator. During uphill travel, the electrical system also supports the mechanical / hydraulic system via the generator, and the combustion engine runs at only minimal speed. This saves fuel.

[0053] The Figures 6d , 6e show different recuperation processes when braking the vehicle, especially when driving downhill. According to the design in Figure 6dIn overhead line operation, the electrical energy recovered by the electric motors during regenerative braking is used as in Figure 6b The generator is then provided with the power, which then acts as an electric motor to drive the diesel engine shaft and / or the hydraulic system. There is no energy flow back into the overhead line system. In contrast, in the design according to Figure 6e The energy recovered through braking is also fed back into the overhead line system. Alternatively, or in addition, the energy could also be buffered in an internal storage unit of the vehicle.

Claims

1. System, comprising an overhead line system (20) for the electrical supply of the travel drive of one or more construction machines for the transport of unit load and bulk load, which comprises at least one pair of lines (21a, 21b) which extend in parallel along the driving route and carry current of opposite polarity, and the system further comprising a construction machine, which comprises trolleys (10), wherein the trolleys (10) electrically contact the line (21a, 21b), characterized in that each line (21a, 21b) each line is equipped at the end side with at least one guide aid (22a, 22b), which forms a supply channel, for accommodating and guiding the head of the trolleys (10), wherein the supply channel converges in the direction of the associated line, and in that both current collectors (10) are actively movable in the vertical and horizontal directions.

2. System according to claim 1, characterized in that the channel width and / or the channel height of the supply channel of the guide aid (22a, 22b) is reduced in the direction of the line (21a, 21b).

3. System according to any one of the claims 1 or 2, characterized in that the guide aids (22a, 22b) of a line pair (21a, 21b) are arranged at the same level next to one another viewed in the direction of travel, wherein the spacing of the center axes of both guide aids (22a, 22b) optionally can be larger than the predominant spacing of the overhead line pair (21a, 21b).

4. System according to any one of the preceding claims 2 or 3, characterized in that the channel width of each guide aid (22a, 22b) is defined by two oppositely disposed side walls (23, 24), wherein the side walls extend with an identical inclination toward the center axis from the outside to the inside in the line direction for a symmetrical reduction of the channel width, or only the outer side wall extends at an incline toward the center axis while the inner side wall extends in parallel with the overhead line axis.

5. System according to any one of the preceding claims, characterized in that the guide aids (22a, 22b) of a line pair (21a, 21b) are arranged offset from one another in the direction of travel.

6. System in accordance with claim 5, characterized in that the spacing between the lines (21a, 21b) extending in parallel is enlarged in the region of at least one guide aid (22a, 22b), in particular by a lateral leading away of the line section of the first line that extends in parallel with the guide aid of the second line, and / or in that the width of the supply channel of at least one guide aid is at least initially larger than the regular spacing between the lines (21a, 21b) extending in parallel.

7. System according to any one of the preceding claims, characterized in that a visual mark is provided on the floor in the region of at least one guide aid (22a, 22b) for the operator of the construction machine to assist him in the introduction of the current collector heads (12a, 12b) into the corresponding guide aid (21a, 21b), in particular in the form of a graphic application to the floor and / or of an optical projection onto the floor and / or by means of one or more illuminants for forming a beacon for navigation.

8. System according to any one of the preceding claims, wherein the construction machine is configured in particular for mining or mining operation, and is equipped with an electric travel drive.

9. Construction machine in electric connection with the overhead line system (20) according to claim 1, characterized in that the trolleys (10) provide a passive adjustment possibility in the horizontal and / or vertical directions, with a passive adjustment only taking place after a successful mechanical contact of the trolleys (10) with the overhead line (21a, 21b) during overhead line operation of the vehicle to ensure a contact pressure of the trolleys (10) at the overhead line that is as constant as possible, and in that the trolleys (10) preferably are arranged at the vehicle front and / or laterally offset from an operator's cabin of the construction machine, ideally outside the field of view of the machine operator, and in that preferably a projecting roof (4) of the construction machine, in particular with a design of the construction machine as a dump truck, comprises a corresponding cutout to enable a lowering of the current collector heads (12a, 12b) onto a placement surface (3) disposed beneath the projecting roof (4).

10. System according to any one of the preceding claims 8 to 9, characterized in that one or more mirrors and / or camera / monitor combinations are provided to allow the machine operator a visual monitoring of the proper contact of the trolleys (10) with the overhead line system (20).

11. System according to any one of the claims 8 to 10, characterized in that the edge of the projecting roof (4) provides a suitable elevated portion or sill in the region of the cutout to protect the current collector heads (12a, 12b) disposed thereunder from dropping bulk load or unit load.

12. System according to any one of the claims 8 to 11, characterized in that a control unit is provided that controls the raising, lowering, and centering of the current collector heads (12a, 12b) in an automated manner during the travel movement.

13. System according to any one of the claims 8 to 12, characterized in that the construction machine comprises a diesel-electric travel drive and the control unit is designed such that a switchover is made between diesel-electric and electric travel drive of the vehicle if the at least one trolley (10) is in contact with the overhead line system (20).

14. Use of a system in accordance with claim 1 for the supply of the at least one construction machine with electric energy on a mountain road.