Current collector and road vehicle having such a current collector

Abstract

The invention relates to a current collector (2) for a road vehicle (1) for feeding traction energy from contact wires (5) of an electrical overhead line system. Said current collector comprises an articulated support linkage system (8), which can be rotatably supported on the road vehicle (1) via a base joint (15) and which supports two contact rockers (12, 13) rotatably mounted via a respective rocker joint (22). Each of the contact rockers (12, 13) has two contact strips (14) that are supported resiliently on the respective rocker joint (22) via leaf springs (23). A lifting device (17) is used to raise the support linkage system (8) from a rest position, in which the contact rockers (12, 13) are lowered close to the vehicle, into an operating position, in which the contact rockers (12, 13) are raised in order to establish electrical contact between the contact strips (14) and the contact wires (5). The leaf springs (23) are designed to be electrically insulating for potential separation between an overhead line potential, on which the contact strips (14) lie when the contact wires (5) are electrically contacted, and a vehicle potential, on which the support linkage (8) lies. According to the invention, a leaf spring (23) has at least one insulation barrier (32), which is upright on a surface (O) of the leaf spring (23) and transverse to a longitudinal direction (L) of the leaf spring (23). The longitudinal direction (L) points from a first fastening point (24) of the leaf spring (23), at which the leaf spring is connected to a contact strip (14), to a second fastening point (25) of the leaf spring (23), at which the leaf spring is connected to a rocker joint (22). As a result, the availability of the current collector (2) for supplying traction energy can be increased even in winter road conditions.

Description

[0001] Description

[0002] Pantograph and road vehicle with such a pantograph

[0003] The invention relates to a current collector for a road vehicle according to the preamble of patent claim 1.

[0004] From the published patent application DE 10 2021 208 951 A1, such a pantograph for an electrically or hybrid-electrically powered road vehicle is known, which is intended for feeding traction energy from a two-pole electrical overhead line system. This pantograph comprises a main frame supported on a chassis, i.e., the undercarriage of the road vehicle, and on which a support rod assembly with a lower arm and an upper arm is mounted. The lower arm is rotatably connected to the main frame via a base joint and to the upper arm via an arm joint. On the contact wire side, the support rod assembly carries two adjacent contact rockers, each rotatably connected to the upper arm via a rocker joint. Each contact rocker has two contact strips that are resiliently supported on the respective rocker joint via leaf springs.The support rods can be moved up and down like a pantograph using a lifting device, allowing electrical contact to be established and broken between the contact strips and the contact wires of the overhead line system. The leaf springs are electrically insulated to provide potential separation between an electrical overhead line potential, to which the contact strips are exposed when the contact wires are electrically connected, and an electrical vehicle potential, to which the support rods are exposed. The vehicle potential can be an intermediate potential, which is electrically insulated from a chassis potential, to which the chassis of the road vehicle is exposed.

[0005] The electrical insulation between the overhead line potential and the intermediate potential is monitored by the pantograph, as is the electrical insulation between the intermediate potential and the chassis potential. Should one of the electrical insulations exhibit a fault, the support rods are lowered to interrupt the electrical contact between the contact strips and the contact wires before the overhead line potential can reach the chassis or undercarriage of the road vehicle, which could pose an electrical hazard to persons.

[0006] It has been shown that during winter road operation of a pantograph described above, a critical insulation resistance can be undershot without any noticeable damage to the electrical insulators or to the leaf springs, which themselves act as insulators due to their material properties. This leads to the pantograph being disconnected due to the lowering of the support rods and, consequently, to an interruption of the power supply from the overhead line system. The present invention recognizes that the critical undershoot of the insulation resistance can be caused by electrically conductive deposits on the surface of the leaf springs, which can form in saline, humid environments—for example, by the spray stirred up by vehicles on salted roads.

[0007] The invention is therefore based on the object of providing a pantograph of the type mentioned above with increased availability for the supply of traction energy even in winter road conditions.

[0008] The object is achieved according to the present invention by a generic current collector having the features specified in the characterizing part of patent claim 1.

[0009] The invention is based on a pantograph for an electrically or hybrid-electrically powered road vehicle, for example a heavy commercial vehicle such as a semitrailer tractor. The pantograph is intended for feeding electrical traction energy from contact wires of a two-pole electrical overhead line system arranged trackside in order to supply an electric or hybrid-electric traction drive of the road vehicle with energy while in motion. The pantograph comprises an articulated support rod, which can be rotatably supported on the road vehicle via a base joint on the vehicle side and which, on the contact wire side, carries two contact rockers, each rotatably mounted via a rocker joint. The support rod can have a lower arm and two upper arms, which can be raised and lowered via drawbars and coupling rods in the manner of a pantograph.Each of the contact strips has two contact strips extending parallel to a rotational axis of the respective contact strip joint. A contact strip can have an elongated graphite contact strip, which is fastened in a contact strip holder. Downwardly curved contact horns can be arranged at the lateral ends of the contact strip. Each of the contact strips is resiliently supported on the respective contact strip joint via leaf springs. The current collector comprises a lifting device for raising the support rod from a lower rest position, in which the contact strips are lowered close to the vehicle, to an upper operating position, in which the contact strips are raised to establish electrical contact between the contact strips and the contact wires.The leaf springs are electrically insulating to provide potential separation between an electrical overhead line potential, to which the contact strips are exposed when the contact wires are electrically connected, and an electrical vehicle potential, to which the supporting rods are exposed. The vehicle potential can be the chassis potential, on which the chassis of the road vehicle rests, or an intermediate potential, which is provided as an additional electrical potential layer between the overhead line potential and the chassis potential and is insulated from them. The leaf springs can be made of a flexurally elastic, high-resistance fiber-plastic composite, for example, glass-fiber-reinforced plastic. They are lightweight and completely or at least partially electrically insulating.

[0010] According to the invention, at least one leaf spring of the leaf springs has at least one insulation barrier, which stands upright on a surface of the at least one leaf spring and transversely to a longitudinal direction of the at least one leaf spring. The longitudinal direction extends from a first fastening point of the at least one leaf spring, at which it is connected to a contact strip, to a second fastening point of the at least one leaf spring, at which it is connected to a rocker joint. An insulation barrier arranged in this way extends the connection path along the surface of a leaf spring between the first and second fastening points and thus makes it more difficult to form an electrically conductive connection between the overhead line potential and the vehicle potential, which could arise due to the deposition of conductive layers on a leaf spring.

[0011] In an advantageous embodiment of the current collector according to the invention, the at least one leaf spring has a plurality of insulation barriers arranged one behind the other in the longitudinal direction, each of which stands upright on the surface of the at least one leaf spring and transversely to the longitudinal direction of the at least one leaf spring. Preferably, two insulation barriers are provided between a first and second fastening point. The resulting further extension of the connecting path increases the protection of the current collector against insulation faults caused by conductive deposits on the leaf springs.

[0012] In a further advantageous embodiment of the current collector according to the invention, an insulation barrier has a sharp outer edge, at least in sections. The sharp outer edge promotes the division or separation of a conductive layer deposited on the insulation barrier and thereby prevents the formation of a leakage path for currents flowing through deposits on the surface of a leaf spring. In a further advantageous embodiment of the current collector according to the invention, an insulation barrier has a centrally arranged through-opening through which the at least one leaf spring is guided such that the insulation barrier encloses the at least one leaf spring in an annular manner.This extends any connection paths between the first and second attachment points along the surface of the leaf spring, preventing the insulation from breaking down, regardless of whether conductive deposits form on the top, bottom or side edges of a leaf spring.

[0013] In a further advantageous embodiment of the current collector according to the invention, the at least one leaf spring has a rectangular cross-section, and the through-opening of the insulation barrier is designed to be congruent with the cross-section. The sharp outer edge extends rectangularly around the through-opening, so that a barrier height extending from the through-opening to the outer edge is constant all around. This design ensures that the insulation barrier or barriers equally prevent the formation of low-resistance creepage paths on all sides of the leaf spring.

[0014] In a further advantageous embodiment of the current collector according to the invention, the insulation barrier is bonded to the surface of the at least one leaf spring by an adhesive layer. This prevents the insulation barriers from creeping under by preventing conductive deposits from penetrating the gap between the insulation barrier and the leaf spring, since this joint is sealed by the adhesive, for example, a silicone.

[0015] In a further advantageous embodiment of the current collector according to the invention, the insulation barrier is made of a silicone material, preferably room-temperature-curing silicone rubber. This so-called RTV silicone advantageously cures without the use of high temperatures within a specified vulcanization time. This allows insulation barriers according to the invention to be produced quickly and efficiently. The surface of such insulation barriers promotes the beading and drainage of moist, conductive deposits.

[0016] The object is further achieved by a road vehicle for operation on a trackside, two-pole electrical overhead line system, which comprises an electric traction drive and a current collector according to one of the preceding claims for feeding electrical traction energy from contact wires of the overhead line system. Further features and advantages of the current collector according to the invention will become apparent from the following description with reference to the drawings, in which

[0017] FIG 1 shows a road vehicle according to the invention with a current collector according to the invention in a side view,

[0018] FIG 2 shows the road vehicle with current collector from FIG 1 in a front view, FIG 3 shows a left contact rocker of a current collector according to the invention in a spatial view,

[0019] FIG 4 the left contact rocker from FIG 3 in a side view,

[0020] FIG 5 the left contact rocker from FIG 3 in a plan view,

[0021] FIG 6 shows detail VI from FIG 5 in an enlarged view,

[0022] FIG 7 a leaf spring with insulation barriers of the left contact rocker from FIG 3 to FIG 6 and

[0023] FIG 8 shows a schematic front view of an isolation barrier from FIG 7.

[0024] According to FIGS. 1 and 2, an electrically or hybrid-electrically powered road vehicle 1, for example a semi-trailer tractor, comprises a pantograph 2, via which electrical energy from an overhead line system 3 can be fed into the road vehicle 1 even while the vehicle is moving. The overhead line system 3 is of two-pole design and comprises, spanned over a lane 4, a contact wire 5 for each contact pole to provide electrical energy. The contact wires 5, designed as forward and return conductors, are each suspended from support cables 7 via hangers 6 and form two longitudinal catenaries that are held above the lane 4 by transverse support devices (not shown). The pantograph 2 shown is designed as a half-scissor pantograph and comprises an articulated support rod 8 with a lower arm 9 and two upper arms 10, each of which is connected to the lower arm 9 via a knee joint 11 so as to be independently pivotable.The upper arms 10 carry two contact rockers 12, 13 on the contact wire side, which are arranged next to one another and each supported by a rocker joint 22, namely a right-hand contact rocker 12 as seen in the vehicle's longitudinal direction X and a left-hand contact rocker 13 arranged laterally next to it. Each of the contact rockers 12, 13 has two contact strips 14 which are arranged parallel to a rotation axis D of the respective rocker joint 22 and one behind the other with respect to the vehicle's longitudinal direction X. To link the pantograph 2 to the road vehicle 1, the lower arm 9 is pivotally connected to the road vehicle 1 on the vehicle side via a base joint 15 and is supported on a rod base 16. A lifting device 17 is coupled to the support rod 8 such that the contact rockers 12, 13 can be raised and lowered.The lifting device 17 can be designed as an air spring bellows which, when pressurized via suitable mechanical coupling means, generates a torque in the base joint 15 which lifts the contact rockers 12, 13.

[0025] In a lower rest position of the contact rockers 12, 13, the support rod 8 of the unwired pantograph 2 is folded together so that the road vehicle 1 does not exceed the maximum permissible vehicle dimensions for operation outside electrified routes and the pantograph 2 is in an electrically secured state. To wire the pantograph 2, the lower arm 9 is raised, with tension and coupling rods (not shown) forcing the upper arms 10 to be raised until the contact rockers 12, 13 have reached their upper contact position shown in FIGS. 1 and 2, in which electrical contact is established between the contact strips 14 and the contact wires 5.For this purpose, it is necessary that the road vehicle 1 is located sufficiently centrally in the electrified lane 4 with respect to the vehicle transverse direction Y so that the contact points of the contact wires 5 are located within a working area of ​​the contact strips 14.

[0026] According to FIG 1, the pantograph 2 is arranged as a module behind a driver's cab 18 of the road vehicle 1 and is supported directly or indirectly on a vehicle frame 19 of the road vehicle 1. The road vehicle 1 comprises an electric traction drive 20, which can be supplied with traction energy from the overhead line system 3 by means of the pantograph 2 while traveling on the electrified lane 4. Away from electrified lanes 4, the traction energy can be provided by a vehicle-mounted energy storage unit 21, which can also be charged with electrical energy from the overhead line system 3 by means of the pantograph 1 while traveling on an electrified lane 4, or by a diesel generator (not shown).

[0027] According to FIGS. 3 to 6, which show in more detail the left-hand contact rocker 13 as viewed in the vehicle's longitudinal direction X, the two contact strips 14, which extend parallel to the axis of rotation D of the rocker joint 22, are each resiliently supported on the rocker joint 22 via four leaf springs 23. In FIGS. 3 to 6, the rocker joint 22 and the support rod 8 are not shown for clarity. In the illustrated embodiment, four leaf springs 23 are provided, extending from a front contact strip 14 to a rear contact strip 14, each of which has a rectangular, flat cross-section - as can also be seen in particular in FIG. 7. Each leaf spring 23 has first fastening points 24, at which it is connected or fixed to one of the contact strips 14, and second fastening points 25, at which it is connected or fixed to the rocker joint 22.Alternatively, eight leaf springs can be provided, each having a first fastening point 24 and a second fastening point 25 for connection to contact strips 14 or rocker joint 22. In the illustrated case of continuous leaf springs 23, two are arranged one above the other as seen in the vehicle's vertical direction Z, with one pair of leaf springs 23 extending through an inner rocker box 26 and the other pair of leaf springs extending through an outer rocker box 27. The two rocker boxes 26, 27 are connected to one another by the rocker joint 22 (not shown) and each provide four second fastening points 25 for the leaf springs 23. Each contact strip 14 comprises a contact strip 29, preferably made of graphite, fastened in a contact strip holder 28, as well as downwardly bent end horns 30.At the ends of each contact strip holder 28, two contact strip holders 31 are attached, each of which provides the first attachment points 24 for two leaf springs 23.

[0028] The leaf springs 23 are electrically insulating for potential separation between an electrical overhead line potential, to which the contact strips 14 are exposed when the contact wires 5 are electrically contacted, and an electrical vehicle potential, to which the support rods 8 are exposed. According to the invention, the leaf springs 23 have at least one insulation barrier 32, which stands upright on a surface O of the at least one leaf spring 23 and transversely to a longitudinal direction L of the leaf spring 23. The longitudinal direction L of a leaf spring 23 extends from a first fastening point 24 to a second fastening point 25—in the illustrated embodiment, parallel to the vehicle longitudinal direction X.

[0029] In the illustrated embodiment - particularly with reference to FIGS. 7 and 8 - each leaf spring 23 has two insulation barriers 32 arranged one behind the other in the longitudinal direction L between the first fastening point 24 and the second fastening point 25. Each insulation barrier 32 stands upright on the surface O and transversely to the longitudinal direction L of the leaf spring 23 and has, at least in sections, a sharp outer edge 33. Each insulation barrier 32 has a centrally arranged through-opening 34 through which the at least one leaf spring 23 is passed such that the insulation barrier 32 encloses the leaf spring 23 in a ring shape. In the illustrated embodiment, the leaf springs 23 have a rectangular cross-section, to which the through-openings 34 of the insulation barriers 32 are congruent.This allows the insulation barrier 32 to be bonded to the surface O of the leaf spring 2 by an adhesive layer 35 that tightly seals the gap between the through-opening 34 and the leaf spring 23. The sharp outer edge 33 extends rectangularly around the through-opening 34, so that a barrier height H extending from the through-opening 34 to the outer edge 33 is constant all around. The insulation barriers are made of a silicone material, preferably room-temperature-curing silicone rubber.

Claims

Patent claims 1. A current collector (2) for an electrically or hybrid-electrically powered road vehicle (1) for feeding electrical traction energy from contact wires (5) of a trackside, two-pole electrical overhead line system (3), comprising - an articulated support rod (8) which can be rotatably supported on the road vehicle (1) via a base joint (15) on the vehicle side and which carries two contact rockers (12, 13) on the contact wire side, each rotatably mounted via a rocker joint (22), - wherein each of the contact rockers (12, 13) has two contact strips (14) extending parallel to a rotational axis (D) of the respective rocker joint (22), which are resiliently supported on the respective rocker joint (22) via leaf springs (23), and - a lifting device (17) for raising the support rod (8) from a lower rest position, in which the contact rockers (12, 13) are lowered close to the vehicle, to an upper operating position, in which the contact rockers (12, 13) are raised to establish electrical contact between the contact strips (14) and the contact wires (5), - wherein the leaf springs (23) are designed to be electrically insulating for potential separation between an electrical overhead line potential, on which the contact strips (14) are located when the contact wires (5) are electrically contacted, and an electrical vehicle potential, on which the support rods (8) are located, characterized in that - that at least one leaf spring (23) of the leaf springs (23) has at least one insulation barrier (32) which stands upright on a surface (O) of the at least one leaf spring (23) and transverse to a longitudinal direction (L) of the at least one leaf spring (23), - wherein the longitudinal direction (L) points from a first fastening point (24) of the at least one leaf spring (23), at which it is connected to a contact strip (14), to a second fastening point (25) of the at least one leaf spring (23), at which it is connected to a rocker joint (22).

2. Current collector (2) according to claim 1, - wherein the at least one leaf spring (23) has a plurality of insulation barriers (32) arranged one behind the other in the longitudinal direction (L), each of which stands upright on the surface (O) of the at least one leaf spring (23) and transversely to the longitudinal direction (L) of the at least one leaf spring (23).

3. Current collector (2) according to claim 1 or 2, - wherein an insulation barrier (32) has at least in sections a sharp outer edge (33).

4. Current collector (2) according to one of claims 1 to 3, - wherein an insulation barrier (32) has a centrally arranged through-opening (34) through which the at least one leaf spring (23) is guided such that the insulation barrier (32) surrounds the at least one leaf spring (23) in a ring shape.

5. Current collector (2) according to claim 4, - wherein the at least one leaf spring (23) has a rectangular cross-section and the through-opening (34) of the insulation barrier (32) is congruent with the cross-section, - wherein the sharp outer edge (33) extends rectangularly around the through opening (34), so that a barrier height (H) extending from the through opening (34) to the outer edge (33) is constant all around.

6. Current collector (2) according to one of the preceding claims, - wherein the insulation barrier (32) is connected to the surface (O) of the at least one leaf spring (23) by an adhesive layer (35).

7. Current collector (2) according to one of claims 2 to 6, - wherein the insulation barrier (32) is made of a silicone material, preferably of room temperature crosslinking silicone rubber.

8. Road vehicle (1) for operation on a track-side, two-pole, electrical overhead line system (3), comprising - an electric traction drive (20) and - a pantograph (2) according to one of the preceding claims for feeding electrical traction energy from contact wires (5) of the overhead line system (3).

Images