A CURRENT COLLECTOR DEVICE FOR A VEHICLE

Abstract

The present invention relates to a current collector device (120) for mounting on a vehicle (100) to transmit electric power between a current conductor (130) located in the surface of a road (110) and the vehicle (100), wherein the current collector device (120) comprises a base (170) for connecting the current collector device to the vehicle, an elongated current collector arm (150) that is in operable connection with the base and a current collector pick-up head (160) attached to the elongated current collector arm distally from the base. The current collector device (120) further comprises at least one vane (180, 280, 380,480) arranged on the elongated current collector arm (150), the at least one vane (180, 280,380, 480) being configured to increase the surface area of the elongated current collector arm (150). The at least one vane (280, 280a-c, 380) is slanted towards the current collector pick-up head (160).

Claims

1.-13. (canceled)

14. A current collector device (120) for mounting on a vehicle (100) to transmit electric power between a current conductor (130) located in the surface of a road (110) and the vehicle (100), wherein the current collector device (120) comprises: a base (170) for connecting the current collector device to the vehicle; an elongated current collector arm (150) that is in operable connection with the base; a current collector pick-up head (160) attached to the elongated current collector arm distally from the base; and wherein the current collector device (120) further comprises at least one vane (180, 280,380, 480) arranged on the elongated current collector arm (150), the at least one vane (180, 280,380, 480) being configured to increase the surface area of the elongated current collector arm (150), and wherein the at least one vane (280, 280a-c, 380) is slanted towards the current collector pick-up head (160).

15. A current collector device (120) according to claim 14, comprising at least two vanes (280, 280a-c).

16. A current collector device (120) according to claim 14, comprising at least three vanes (280, 280a-c).

17. A current collector device (120) according to claim 14, comprising at least five vanes (280, 280a-c).

18. A current collector device (120) according to claim 16, wherein the vanes (280, 280a-c) are separated by at least 1 cm.

19. A current collector device (120) according to claim 14, wherein the slanting angle (a) of the vane or vanes from a longitudinal axis of the elongated current collector arm (150) is between 10 degrees and 30 degrees.

20. A current collector device (120) according to claim 14, wherein the slanting angle (a) of the vane or vanes from a longitudinal axis of the elongated current collector arm is between 30 degrees and 60 degrees.

21. A current collector device (120) according to claim 14, wherein the slanting angle (a) of the vane or vanes from a longitudinal axis of the elongated current collector arm is between 60 degrees and 80 degrees.

22. A current collector device (120) according to claim 14, wherein the elongated current collector arm is arranged to be controllable for vertical and transverse displacement relative to the longitudinal axis of the vehicle, and the current collector device further comprises at least one actuator arranged to effect a vertical or transverse displacement of the current collector pick-up head.

23. A current collector device (120) according to claim 14, wherein the vane(s) are aerodynamically shaped.

24. A vehicle (100) comprising a current collector device according to claim 14.

25. An elongated current collector arm (150) for a current collector device (120) for mounting on a vehicle (100) to transmit electric power between a current conductor (130) located in the surface of a road (1 10) and the vehicle (100), which elongated current collector arm (150) comprises: at least one vane (180, 280,380, 480) arranged on the elongated current collector arm (150) and being slanted towards the current collector pick-up head (160), the at least one vane (180, 280,380, 480) being configured to increase the surface area of the elongated current collector arm (150).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In the following text, the invention will be described in detail with reference to the attached drawings. These schematic drawings are used for illustration purposes only and do not in any way limit the scope of the invention. In the drawings:

[0032] FIG. 1 shows a schematic vehicle comprising a current collector device travelling on an electric road system;

[0033] FIG. 2 shows a schematic front view of a current collector device;

[0034] FIG. 3 shows a schematic front view of an alternative current collector device;

[0035] FIG. 5 shows a schematic isometric view of a current collector device according to an embodiment of the invention;

[0036] FIG. 6 shows a schematic isometric view of a current collector device according to an embodiment of the invention;

[0037] FIG. 7 shows a schematic isometric view of a current collector device according to an embodiment of the invention;

[0038] FIG. 8 shows a schematic isometric view of a current collector device according to an embodiment of the invention; and

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

[0039] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout.

[0040] Generally, an embodiment of a current collector device will now be described which aims at reducing the risk of a creep current reaching the chassis structure of a vehicle. First, the general teachings of current collector devices will be explained with reference to FIGS. 1, 2 and 3. Thereafter, embodiments of the present invention will be elucidated with reference to FIGS. 5-9.

[0041] FIG. 1 shows a schematic electric road system (ERS) where a vehicle 100 is travelling on a road 110 provided with a current conductor 130 for supplying electric current to the vehicle 100. The vehicle 100 is provided with a conductive current collector device 120, which can be lowered into contact with the current conductor 130 comprising parallel current conducting rails 140 located in the surface of the road 110. The vehicle can be an electric vehicle or a hybrid electric vehicle.

[0042] The current collector device 120 comprises a base 170 connecting and attaching the current collector device 120 to the chassis structure of the vehicle 100, an elongated current collector arm 150 arranged to be displaced between a retracted, inactive first position and a deployed, operative second position. In use, the current collector arm 150 and a pick-up unit 160 are lowered into contact with the current conductor 130 using suitable actuators (not shown). The actuator(s) may be arranged in the base 170 of the current collector device 120. The pick-up unit 160 has a pair of contact elements 161, 162. FIG. 1 shows the current collector arm 150 in its operative position. Suitable actuators are provided for moving the current collector arm 150 at least in the vertical direction of the vehicle 100. Note that the current collector pick-up head 160 is attached to the elongated current collector arm 150 distally from the base 170. In other words, the current collector pick-up head 160 and the base 170 are arranged at opposite ends of the elongated current collector arm 150.

[0043] It may be noted that suitable electrical power cables are typically used to transfer an electrical current from the pick-up unit 160 and the pair of contact elements 161, 162 to electrical contact point of the vehicle. The electrical power cables are omitted in all the drawings for the sake of brevity. However, the skilled addressee realizes that electrical power cables may be led on the outside of the elongated current collector arm, or inside the elongated current collector arm, or in any other way such that an electrical connection for the transfer of electrical current from the pick-up unit 160 and the pair of contact elements 161, 162 is provided.

[0044] In this context, the current collector device will be described as comprising a displaceable current collector arm for the pick-up unit, which arm can be displaced vertically either in a straight line or in an arcuate path relative to a pivot with a horizontal axis on the vehicle. The positioning means for such an arm can also comprise actuator means for displacing the arm in the transverse direction of the vehicle, either in a transverse straight line or in an arcuate path relative to a pivot with a vertical axis on the vehicle. Alternatively, the transverse positioning means can comprise suitable control means connected to an electronically controllable steering system in the vehicle, wherein lateral positioning of the vehicle relative to the electrical conductor can be performed using a pair of steerable wheels. Positioning can further be performed using a combination of the above means, for instance if the vehicle must be displaced in the lateral direction to bring the current conductor within the transverse range of the displaceable arm carrying the current collector. The design of the current collector device is described in further detail below.

[0045] FIG. 2 shows a schematic front view of a current collector device 220. The current collector arrangement 220 is mounted on a schematically indicated vehicle 200 located over a schematic section of a road 210. A current conductor 230 comprising a first and a second power rail 231, 232 for supplying DC current is located in the surface of the road 210. The current collector arrangement 220 comprises a current collector arm 250 and a pick-up unit 260 with a pair of contact elements 261, 262 for collecting current from the respective first and second power rails 231, 232. The current collector arm 250 is attached to a vertical positioning means (not shown) for displacing the current collector arm 250 from a retracted first position P1 adjacent the vehicle 200 to an active second position P2 in contact with the current conductor 230. The vertical displacement is indicated by the arrow V. The lowering of the current collector arm 250 into the active second position is performed when its detected that the first and second contact elements 261, 262 are vertically aligned with their respective first and second power rails 231, 232. Alternatively, a movement towards the second active position may be started when a current conductor is detected and then be steered towards an optimal horizontal position. The current collector arm 250 is attached to the vehicle 200 via a horizontal positioning means 270 for displacing the current collector arm 250 in a transverse direction.

[0046] In FIG. 2, the current collector arm 250 is shown in an intermediate position during displacement towards the second position P2. Prior to lowering the current collector arm 250 into the second position P2, it is necessary to locate and track the current conductor 230. According to the example in FIG. 2, locating and tracking the current conductor 230 can be performed by using one or more vertical antennas (not shown) used for detecting the position of a signal cable 275 located between or adjacent the current conductor 230. However, the invention is not limited to this method of locating the current conductor.

[0047] In the example shown in FIG. 2, the current collector arm 250 and the vertical positioning means are attached to a transverse positioning means 270. The vertical positioning means is arranged to displace the current collector arm 250 and the pick-up unit 260 in the vertical direction of the vehicle 200 as indicated by the arrow V. The horizontal positioning means 270 is arranged to displace the current collector arm 250 and the pick-up unit 260 in the transverse direction of the vehicle 200 as indicated by the arrow T. The transverse positioning means 270 is controlled to displace the current collector arm 250 in the transverse direction of the vehicle 200, initially to locate and subsequently to track the current conductor 230. Tracking is performed to maintain the first and second contact elements 261, 262 in vertical alignment with their respective first and second power rails 231, 232.

[0048] FIG. 3 shows a schematic front view of an alternative current collector device 320. The current collector device 320 is mounted on a vehicle 300 located over a section of a road 310. A current conductor 330 comprising a first and a second power rail 331, 332 for supplying DC current is located in the surface of the road 310. The current collector arrangement 320 comprises a current collector arm 350 and a pick-up unit 360 with a pair of contact elements 361, 362 for collecting current from the respective first and second power rails 331, 332. The current collector arm 350 is attached to a vertical positioning means (not shown) for displacing the current collector arm 350 from a retracted first position adjacent the vehicle 300 to an active second position (indicated in the figure) in contact with the current conductor 330. The lowering of the current collector arm 350 into the active, second position is performed when its detected that the first and second contact elements 361, 362 are vertically aligned with their respective first and second power rails 331, 332. Alternatively, a movement towards the second active position may be started when a current conductor is detected and then be steered towards an optimal horizontal position. The current collector arm 250 is attached to the vehicle 300 via a pivoting means 370 for displacing the current collector arm 250 about a vertical axis X. During this displacement, the pick-up unit 360 is moved along an arcuate path relative to the vertical axis X on the vehicle 300.

[0049] In reference to the above, and in general with regard to current collector devices; the current conductor is preferably, but not necessarily located in a predetermined transverse position in the longitudinal direction of the road surface. The vehicle is provided with means (not shown) for detecting and/or locating the position of the current conductor relative to the vehicle and/or suitable road markers on or along the road. The current collector device comprises a displaceable current collector arm that is arranged to be controllable for vertical and transverse displacement relative to a longitudinal axis of the vehicle, either via linear movement or arcuate movement. The longitudinal axis of the vehicle extends in the main direction of forward movement of the vehicle. A vertical downwards displacement is performed in order to place a pick-up unit comprising contact elements mounted on a free end of the current collector arm into an optimal charging position, in order to effect transmission of current. A vertical upwards displacement is performed in order to retract the current collector arm, when the current transmission has been interrupted. The current collector arrangement may comprises controllable actuator(s), mounted in the base, arranged to effect the vertical displacement the current collector arm and an electronic control unit (not shown) for controlling at least power transmission in and displacement of the current collector arm. The control unit is arranged to detect when the vehicle enters or leaves an ERS road and to initiate the power transmission after a completed deployment of the current collector arm and to interrupt the power transmission prior to retraction of the current collector arm.

[0050] Hence, in operation, it is first determined that the vehicle has entered an ERS road and that the current collector arm should be moved from the retracted position into the deployed position in contact with a current conductor. A signal is transmitted to the ECU which will in turn transmit signals to the actuator(s) causing the current collector arm to be deployed downwards. When the current collector arm reaches its end position in contact with a current conductor, the pressure applied by the actuator(s) will cause a downward force ensuring a sufficient contact force with the conductor.

[0051] Subsequently, it can be determined that the vehicle is about to leave the ERS road and that the current collector arm should be moved from the deployed position into the retracted position. Alternatively, a retraction can also be initiated if an obstacle is detected on the conductor, requiring retraction of the control arm or evasive action of the vehicle. A signal is transmitted to the ECU which in turn transmits signals to the actuator(s) causing the current collector arm to be retracted upwards. When the current collector arm reaches its retracted position adjacent the vehicle, the ECU transmits signals to halt the operation of the actuator(s).

[0052] FIG. 5 shows an exemplary embodiment of a current collector device 120 according to the invention, for the sake of brevity the current collector device 120 is essentially similar in function with regard to activation and displacement as the current collector devices described above in conjunction with FIGS. 1, 2 and 3. The current collector device 120 comprises a base 170, an elongated current collector arm 150, and a current collector pick-up head 160. The base 170 is attachable to a vehicle. The elongated current collector arm 150 extends from the base 170 to the current collector pick-up head 160 attached at the free end. Stated differently, the elongated current collector arm 150 is attached at a first end to the base 170. At the second end of the elongated current collector arm 150, opposite to the first end, the current collector pick-up head 160 is attached. The second free end of the elongated current collector arm is free to be displaced as described above in conjunction with FIGS. 1, 2 and 3. Hence, the current collector pick-up head 160 is attached to the elongated current collector arm 150 distally from the base 170.

[0053] The current collector device 120 further comprises a vane 280, which increases the surface area between the current collector pick-up head 160 and the base 170, thereby reducing the likelihood that a creep current reaches the base from the current collector pick-up head 160. The vane 280 slants towards the current collector pick-up head 160. In other words, the vane 280 is shaped as a cone with the opening towards the current collector pick-up head 160. As the current collector pick-up head 160 is arranged on the free end of the of the current collector arm 150, the cone shaped vane 280 will have an opening facing away from the main direction of locomotion of a vehicle onto which the current collector device is mounted. The inner surface of the vane 280, defined as the surface facing rearwards, can thus be further protected from contaminants such as water, dirt, ice, and snow.

[0054] The vane 280 may extend radially to a suitable distance, for example, the radii of the vane may be in the range of 5 cm to 50 cm. In FIG. 5 the vane 280 is placed approximately halfway between the two ends of the elongated current collector arm 150. However, it is in principle possible to arrange the vane 280 anywhere along the elongated current collector arm 150.

[0055] The vane 280 may be separate from the elongated current collector arm 150 and attached via any known means such as glue, welding, nut and bolt arrangements, crimp fit or the like. Alternatively, the vane 280 may be formed integrally with the elongated current collector arm 150. Hence, the vane 280 may be made of the same material as the elongated current collector arm 150, or from another material. The vane 280 may be made of a lightweight and strong material, such as stainless steel, aluminium, titanium, plastic or a metallic alloy. Likewise, the elongated current collector arm 150 may be made of a lightweight and strong material, such as stainless steel, aluminium, titanium, plastic or a metallic alloy. The vane 280 and/or the elongated current collector arm 150 may comprise a coating (not illustrated) to protect the vane and/or elongated current collector arm 150 from the harsh conditions below a vehicle. The coating is preferably electrically isolating. The coating may be hydrophobic and/or oleophobic to facilitate the removal of contaminants on the surface of the vane 280 and/or elongated current collector arm 150.

[0056] FIG. 6 shows another embodiment of a current collector device according to the inventive concept. The current collector device comprises three vanes 280a, 280b, 280c, shaped as cones, arranged on the elongated current collector arm 150. The three vanes 280a, 280b, 280c are spaced apart. The spacing may be even between all three vanes, or there may be a difference in spacing between any two vanes. The spacing between each of the vanes 280a, 280b, 280c is at least 1 cm. The three vanes 280a, 280b, 280c thus forms grooves in between them due to being spaced apart. This means that there will be a reduced risk that contaminants reach into the grooves between the three vanes 280a, 280b, 280c. Further, the surface area is further increased by utilizing a plurality of vanes. Hence, it is understood that while three vanes 280a, 280b, 280c are shown in FIG. 6, the inventive concept also covers embodiments comprising two vanes, or four or more vanes being spaced apart.

[0057] FIG. 7 shows the embodiment of FIG. 6 with a cut-out for illustrating the slanting angle which the vanes 280 (previously denoted 280a, 280b, 280c, here collectively 280) forms against the longitudinal axis of the elongated current collector arm 150. The slanting angle may vary depending on design consideration for the vane(s). For example, the slanting angle may be between 1 degrees and 89 degrees. The slanting angle may oftentimes be between 10 degrees and 80 degrees. For example, the slanting angle may be 15 degrees, 20 degrees 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, or 85 degrees. Further, it is noted that although the cut-out indicates that the elongated current collector arm 150 is solid, the elongated current collector arm 150 may be hollow. Also, the elongated current collector arm 150 is not limited to a particular cross-sectional shape such as square or rectangular indicated by the drawings, the elongated current collector arm 150 may be circular or oval in cross section.

[0058] FIG. 8 shows another embodiment of a current collector device according to the inventive concept. The vane in FIG. 8 is shaped as a cone 380. The vanes 380 is asymmetrical around the elongated current collector arm 150 such that there is a larger radial distance towards the road than towards the vehicle. Stated differently, the radial extent of the vane 380 is larger in a downwards direction than upwards. The vane 380 increases the surface area between the current collector pick-up head 160 and the base 170, and prevent contaminants from the road. Moreover, the asymmetrical vane 380 also functions as balancing weights for the current collector device and may thereby increase the stability of the current collector device.

[0059] The vane(s) may in principle take any shape and are not limited to the embodiments shown herein, in particular the vane(s) may be rectangular, square, or have any other shape. The vane(s) may also be asymmetrical around the elongated current collector arm such that there is a larger radial distance towards the road than towards the vehicle as shown in FIG. 9. Such vanes may act as balancing weight for the current collector device.

[0060] Further, it is understood that the slanting angle referred to in the above description may be chosen depending on the design, number of vanes, and the desired aerodynamic drag of the vanes. Furthermore, the vanes may be designed with another shape than the cone shown in the figures, for example a spherically blunted cone, a bi-conic shape, a tangent ogive cone, a spherically blunted tangent ogive, a secant ogive shape, an elliptical cone, a parabolic cone. The specific shape and parameters of such a vane of course depends on the size and the number of vanes to be used.

[0061] Moreover, the specific and exemplary material and attachment options described in conjunction to FIG. 5 is understood to be applicable to all the embodiments of vane(s) described in FIGS. 5-8. The coating described in conjunction to FIG. 5 is of course also applicable for all the embodiments of vane(s) described in FIGS. 5-8 and is only left out for the sake of brevity.

[0062] It is understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes, variants and modifications may be made within the scope of the appended claims.