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EP-4440865-B1 - SLIDABLE CURRENT COLLECTOR AND METHOD FOR CONTACTING CONDUCTOR RAIL

EP4440865B1EP 4440865 B1EP4440865 B1EP 4440865B1EP-4440865-B1

Inventors

  • STRASHNY, IGOR
  • RAJESH, ROOPA

Dates

Publication Date
20260506
Application Date
20230104

Claims (10)

  1. An electric current collector (118) for sliding in a direction along a power rail (108), comprising: a frame (302) having a substrate (308) with a top surface (322) and an underside (324); a busbar (304A) positioned on the top surface (322); and a first terminal (306A-1) and a second terminal (306A-2) aligned in a column along the direction and mounted between the top surface (322) and the underside (324), the busbar (304A) electrically connecting the first terminal (306A-1) and the second terminal (306A-2), wherein the first terminal (306A-1) and the second terminal (306A-2) respectively comprises: a carbon brush (406), a piston (504), a reservoir (506), and a conductive fluid (514) within the reservoir (506), the carbon brush (406) being aligned and electrically connected with the piston (504) along a central axis (510), the conductive fluid (514) radially surrounding and contacting at least a portion of the piston (504) along the central axis (510); an upper section (520) comprising a post (522), the post (522) being hollow and defining at least an upper chamber (526) configured to loosely receive the piston (504) along the central axis (510); and a fluid suspension comprising an insulative fluid (556) within a pliable bladder (546), the fluid suspension connecting the reservoir (506) with the post (522) and enabling movement of the carbon brush (406) along the central axis (510).
  2. The electric current collector (118) of claim 1, further comprising: an angled inner side (310) and an angled outer side (312) on opposite sides of the substrate (308), the angled inner side (310) having a first face (804) on the underside (324) inclined toward the column, the angled outer side (312) having a second face (806) on the underside (324) inclined toward the column; and an inner bumper (318) on the underside (324) between the column and the angled inner side (310), the inner bumper (318) having a first wall (808) inclined toward the column.
  3. The electric current collector (118) of claim 2, further comprising: an inner flange (314) adjacent the angled inner side (310); an outer flange (316) adjacent the angled outer side (312), wherein the inner flange (314) and the outer flange (316) are lower than substrate (308) along the central axis (510).
  4. The electric current collector (118) of claims 1, 2, or 3, further comprising tubes pneumatically connecting the first terminal (306A-1) and the second terminal (306A-2), wherein the first terminal (306A-1) and the second terminal (306A-2) respectively include a cap (330) having an passageway (402) in fluid communication with the upper chamber (526).
  5. The electric current collector (118) of claims 1, 2, or 3, wherein the first terminal (306A-1) and the second terminal (306A-2) respectively further comprise: a body (404) contacting the post (522); and a magnet (410) contacting the body (404), the magnet (410) radially surrounding the central axis (510) and the body (404).
  6. A method, comprising: touching an electrical contact (406) of a slidable terminal (306) on a rail surface (408); clamping the slidable terminal (306) to the rail surface (408) using, at least in part, an attractive force between a magnet surrounding a body (404) of the slidable terminal (306) and the rail surface (408); and applying a downward force along a central axis (510) between the electrical contact (406) and the rail surface (408), the applying comprising: directing a fluid through an upper section (520) of the slidable terminal (306) and into a region confined by an airbag (546), the airbag (546) coupling the upper section (520) and a lower section (500) of the slidable terminal (306) and being positioned radially around the central axis (510), and adjusting pressure for the fluid to a first pressure level within the region; and sliding the electrical contact (406) across the rail surface (408).
  7. The method of claim 6, wherein the first pressure level positions a post (522) of the upper section (520) within a liquid metal (514) of the lower section (500).
  8. The method of claim 7, further comprising: adjusting the pressure for the fluid to a second pressure level, wherein the second pressure level expands the region confined by the airbag (546) and positions the post (522) apart from the liquid metal (514).
  9. The method of claim 8, wherein the second pressure level generates an upward force on the body (404) greater than the attractive force to overcome the clamping.
  10. The method of claims 6, 7, 8, or 9, further comprising: moving the electrical contact (406) angularly with bearings (516) about the central axis (510) during the sliding.

Description

Technical Field The present disclosure relates to a slidable current collector and a method for contacting a conductor rail. More specifically, the present disclosure relates to a slidable current collector having a fluid suspension distributed across an array of terminals and a method for contacting the current collector on a conductor rail with multiple degrees of freedom while sliding. Background Heavy work machines, such as earth-moving vehicles or hauling trucks, require significant power to carry out their functions. The machines themselves can be of substantial weight, and their loads require large amounts of power to move. Diesel engines typically provide that power, but the use of machines powered by diesel engines may not be appropriate in certain environments. For instance, in some implementations, heavy work machines may need to travel large distances through rugged terrain. At a remote mining site, for example, groups of these machines are often employed to ferry extreme loads along roadways, or haul routes, extending between various locations within the mining site. Supplies of diesel fuel may be far away from such locations or not easily delivered to such locations. In addition, the groups of diesel machines can generate significant pollution. A power rail based on the ground may provide electrical power to traveling vehicles such as heavy work machines. In some environments, such as with trains or subways that travel on a fixed track, precise alignment between the fixed track and the power rail can ensure reliable delivery of electrical power to a current collector as the vehicle moves. For a heavy work machine that is freely steerable, however, establishing and maintaining an electrical connection between a current collector attached to an extended arm and the power rail can be particularly challenging. The rails may be slightly uneven, twisted, or curved, possibly leading to disconnections or arcing. Arcing can degrade current flow and damage components. In some environments, such as a mining site, the terrain can also interfere with continuous connection with power rails for a freely steerable work machine along a haul route. The haul route may be uneven, hilly, and pocked, which can lead to steering deviations that could also cause arcing at the current collector. These variations in terrain can also cause the machine to disconnect from the rail, detracting from the value of rail-based delivery of electrical power. While increasing adhesion between the current collector and the rail may decrease disconnections, increased adhesion at the current collector leads to unwanted drag on the arm of the work machine and accelerates wear on the current collector. One approach for contacting a current collector and a power rail is described in US 3 804 997 A ("the '997 patent"). The '997 patent describes a system for a train traveling at high speeds that purports to counteract the fluttering of contact shoes sliding against a powered rail, which can interrupt electrical contact. A contactless force field, which may be magnetic or pneumatic, provides offsetting forces to stabilize the collector shoe against the power rail with fixed spacing during high-speed travel. The system of the '997 patent, however, addresses only fluttering of collector shoes with a vehicle traveling in fixed relation to a powered rail and does not contemplate positional deviations in multiple dimensions between a freely steerable vehicle and the powered rail. Nor does the system of the '997 patent address a risk of the collector shoes becoming detached from the power rail during the positional deviations. As a result, the system of the '997 patent is insufficient for freely steerable vehicles having current collectors sliding over a power rail along a haul route that may vary over diverse terrain. Moreover, US 506 463 A relates to elates to electric railways, and more especially to so-called "trolleys" as is carried by an electromotive vehicle and used for the purpose of establishing electrical connection between a conductor arranged in the vicinity of the line of rails on which the vehicle travels, and an electro motor upon the vehicle. WO 2018/059709 A1 teaches a current collector arrangement arranged to be mounted on a vehicle and to transmit electric power between a current conductor located in the surface of a road and the vehicle. The present invention is directed to overcoming deficiencies of known systems. Summary In accordance with the present invention, an electric current collector and a method as set forth in the independent claims is provided. Preferred embodiments of the invention are claimed in the dependent claims. In an aspect of the invention, an electric current collector for sliding in a direction along a power rail includes a frame having a substrate with a top surface and an underside, a busbar positioned on the top surface, and a first terminal and a second terminal. The first terminal and the second t