Battery-powered rubber-tired gantry crane with onboard charging system

Abstract

A rubber-tired gantry crane (RTG) includes an energy storage device disposed on and configured to provide power to the RTG, a primary charging device disposed on the RTG and configured to charge the energy storage device, and a secondary charging device disposed on the RTG and configured to charge the energy storage device when the RTG is idle or not in operation.

Claims

1. A rubber-tired gantry crane (RTG) comprising: a rechargeable battery disposed on and configured to supply all power needed to operate the RTG, a primary engine-generator disposed on the RTG and configured exclusively to charge the battery when the RTG is in operation, and a secondary engine-generator disposed on the RTG and configured exclusively to charge the battery when the RTG is idle or not in operation.

2. The rubber-tired gantry crane of claim 1, wherein: the secondary engine-generator is smaller than the primary engine-generator.

3. A rubber-tired gantry crane (RTG) comprising: an energy storage device disposed on and configured to supply all power needed to operate the RTG, a primary charging device disposed on the RTG and configured to charge the energy storage device when the RTG is in operation, and a secondary charging device disposed on the RTG and configured to charge the energy storage device when the RTG is idle or not in operation.

4. The rubber-tired gantry crane of claim 3, wherein: the energy storage device comprises at least one rechargeable battery.

5. The rubber-tired gantry crane of claim 3, wherein: the primary charging device comprises an engine-generator.

6. The rubber-tired gantry crane of claim 5, wherein: the engine-generator comprises a hydrogen-powered engine.

7. The rubber-tired gantry crane of claim 5, wherein: the engine-generator comprises at least one engine configured to run on a fuel selected from the group consisting of gasoline, diesel, natural gas, propane, biodiesel, hydrogen or water.

8. The rubber-tired gantry crane (RTG) of claim 1 wherein the secondary charging device comprises an engine-generator.

9. The rubber-tired gantry crane of claim 3, wherein: the secondary charging device is smaller than the primary charging device.

10. The rubber-tired gantry crane of claim 3, wherein: the secondary charging device has no more than half the power of the primary charging device.

11. The rubber-tired gantry crane of claim 3, wherein: the secondary charging device has no more than 25 horsepower.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:

(2) FIG. 1 is an elevational view of a first embodiment of an e-RTG with an onboard charging system according to the invention,

(3) FIG. 2 is an upper left perspective view thereof.

(4) FIG. 3 is an upper right perspective view of a second embodiment of an e-RTG with an onboard charging system according to the invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

(5) FIGS. 1 and 2 show a first embodiment (100) of a battery-powered e-RTG with an onboard charging system according to the invention. The illustrated e-RTG includes an RTG (110) onto which an energy storage device (120), such as a rechargeable battery, is disposed, for example, within an onboard electrical room. The energy storage device supplies all the power needed to operate the RIG, including all container handing operations.

(6) A charging device (150), for example, in the form of a propane gas or diesel engine-generator, is mounted to or otherwise disposed on the RTG, for example in an onboard engine room located away from the truck lane (160) and other hazards.

(7) Unlike the engine-generator of a hybrid RTG, the onboard charging device (150) is configured exclusively to charge the energy storage device (120) and not to drive the motor or motors of the RTG. As a result, it can be much smaller than the typical engine-generator of a hybrid RTG. For example, a 50 horsepower or smaller propane or diesel engine-generator may be used for the charging device to provide enough power to the energy storage device to allow for the continuous operation of the e-RTG, free of interruptions. A 50-horsepower engine-generator would be about 10% the size of a 500 horsepower RTG diesel engine-generator, lowering emissions to just 10% of a conventional, fully diesel-engine powered RTG.

(8) FIG. 3 shows a second embodiment (200) of an e-RTG with an onboard charging system according to the invention. In this alternative embodiment, a secondary charging device (155) is disposed on the e-RTG and is preferably of a smaller size than the primary charging device (150) (shown in FIGS. 1 and 2). For example, if the charging devices are diesel-powered engine generators, the primary engine-generator may be 50 horsepower, while the secondary engine-generator may be 25 horsepower. The secondary charging device (155) is used exclusively to charge the energy storage device (120) when the e-RTG is sitting idle or not in operation. When the e-RTG has stopped operation or is idle, the first charging device will turn off and the secondary charging device will turn on and will begin to charge the energy storage device. The secondary charging device may be further configured to automatically turn off when the energy storage device is fully charged. In this second embodiment, the smaller, secondary charging device may, for example, be installed under the sill beam of the electrical room (120). The smaller secondary charging device further lowers the emissions produced by the e-RTG.

(9) Being fully portable, the e-RTG of the invention requires no power distribution infrastructure. As a result, there is no need to alter the existing shipping terminal facilities, and significant costs and safety hazards can be avoided by eliminating the need for power bars, posts, cabling or any other dedicated power infrastructure.

(10) In addition, use of the e-RTG according to the invention eliminates the need to plug the e-RTG into a charging station after each day's operation, thereby avoiding the need for any charging station infrastructure and the associated labor required to maintain and operate charging stations. The fuel tank of the engine-generator can be sized to be large enough, for example, for weekly or biweekly operation of the e-RTG without the need for refueling.

(11) Like the hybrid RTG, an e-RTG according to the invention can be rapidly refueled by simply refilling the engine-generator, for example, with propane gas or diesel delivered to the e-RTG by truck. Also like the hybrid RTG, the e-RTG of this invention can take advantage of energy recovery mechanisms, such as regenerative braking, to recharge the battery system when the e-RTG is performing braking or container-lowering actions, further improving energy efficiency. Moreover, since the onboard charging device, i.e., engine-generator, is configured exclusively to charge the energy storage device, it can be much smaller than that of a comparable hybrid RTG, further reducing emissions.

(12) In addition, as an alternative to a propane gas or diesel engine-generator, the e-RTG of the invention can utilize a hydrogen-powered engine generator for the onboard charging device. A hydrogen-powered e-RTG according to the invention would have the added benefit of eliminating noxious emissions altogether.

(13) Certain embodiments of a battery-powered e-RTG having an onboard charging system have thus been described and illustrated herein in detail. These embodiments are merely example implementations of the invention and are not to be taken as limiting, the spirit and scope of the invention being limited only by the terms of the appended claims and their legal equivalents.