Electrical drive system for earth moving machinery

Abstract

An electrical drive system that modifies operation between that of a generator and a motor based on changes in operation of a tractor and machine scraper in order to charge the electrical drive system when the machine scraper is empty or being unloaded and to power the drive of the machine scraper when the machine scraper is cutting and loading a bowl of the machine scraper and during the transport of the load from the location of the cutting and loading.

What is claimed is: 
     
         1 . An electrical drive system, comprising:
 a battery pack;   an electrical drive device in electrical communication with the battery pack;   a power control system connected to the electrical drive device;   a power conditioning circuit connected to the electrical drive device and the power control system;   a powered axle connected to the electrical drive device; and   wherein the power control system and the electrical drive device are configured to operate as a generator through passive rotation of the powered axle to create power that is stored in the battery pack;   wherein the electrical drive device and the power control system are configured to operate as a motor by providing power stored in the battery pack to the powered axle;   wherein the electrical drive device and the power control system are configured to operate in an empty phase, a cutting/loading phase, a transport phase, and a fill/dump phase.   
     
     
         2 . The electrical drive system of  claim 1  further comprising a tractor control system and a scraper control system; wherein the tractor control system and the scraper control system are configured to transmit information from at least one sensor with the power control system; and wherein the power control system is configured to command the electrical drive device to operate as a generator and a motor based on information received from the tractor control system and the scraper control system. 
     
     
         3 . The electrical drive system of  claim 2  further comprising the tractor control system having the at least one sensor selected from a group consisting of a tractor speed sensor configured to sense a speed registered by a tractor but not an actual ground speed, a commanded gear sensor configured to sense a gear that the tractor is currently in, an output shaft speed sensor configured to sense the speed of an output shaft of the tractor, an engine torque sensor configured to sense a torque output of an engine of the tractor, an engine speed sensor configured to sense a speed of the engine of the tractor, a coolant temperature sensor configured to sense a coolant temperature of the engine of the tractor, an oil pressure sensor configured to sense an oil pressure of a hydraulic system of the tractor, an estimate ground speed sensor that is configured to calculate an actual ground speed of the tractor that does not account for environmental changes and slippage, and an actual ground speed sensor configured to determine the actual ground speed of the tractor. 
     
     
         4 . The electrical drive system of  claim 2  further comprising the scraper control system having the at least one sensor selected from a group consisting of an apron sensor configured to sense and control a position of an apron of a machine scraper, a cutting edge sensor configured to sense and control a position of a scraper blade of the machine scraper and an angle of a cutting edge of the scraper blade, a load sensor configured to sense a weight of a load carried in a bowl of the machine scraper, and a powertrain cooling system sensor. 
     
     
         5 . The electrical drive system of  claim 1  further comprising a differential, a final drive, a wheel, and a tire connected to the powered axle; wherein one or more pairs of spindles are connected to opposing sides of the differential. 
     
     
         6 . The electrical drive system of  claim 5  further comprising a spacer positioned between the differential and at least one of the pair of spindles, wherein the spacer is configured to adjust a width of the powered axle. 
     
     
         7 . The electrical drive system of  claim 1  further comprising the powered axle extending through a rearward housing of a bolt on rear tube; wherein the battery pack, the electrical drive device, the power control system, and the power conditioning circuit are mounted to the powered axle within the rearward housing. 
     
     
         8 . The electrical drive system of  claim 7  wherein the powered axle is retrofitted to the bolt on rear tube in a position and replacement of a dummy axle. 
     
     
         9 . The electrical drive system of  claim 7  wherein the battery pack is positioned over a centerline of the powered axle extending axially along a length of the powered axle. 
     
     
         10 . The electrical drive system of  claim 7  further comprising at least one cable connecting the battery pack to the electrical drive device; wherein the battery pack is positioned immediately above the electrical drive device. 
     
     
         11 . The electrical drive device of  claim 7  further comprising a differential directly coupled to the electrical drive device. 
     
     
         12 . The electrical drive device of  claim 11  wherein the electrical drive device and the power control system are positioned to a rear of the differential and behind a centerline of the powered axle extending axially along a length of the powered axle. 
     
     
         13 . The electrical drive system of  claim 7  further comprising a machine scraper having a bowl connected to the bolt on rear tube; the bowl having an apron, an ejector, and a scraper blade having a cutting edge; and the machine scraper connected to a tractor. 
     
     
         14 . The electrical drive system of  claim 13  wherein the power control system is configured to command the electrical drive device to operate as a motor to provide power to the powered axle to match a speed of the machine scraper to an actual speed of the tractor. 
     
     
         15 . The electrical drive system of  claim 13  wherein the electrical drive device and the power control system are configured to operate as a motor under a predefined speed and a predefined gear of the tractor, wherein the predefined speed varies based on the predefined gear. 
     
     
         16 . The electrical drive system of  claim 13  wherein the power control system is configured to command the electrical drive device to operate in the empty phase, the cutting/loading phase, the transport phase, and the fill/dump phase based on a condition selected from a group consisting of a condition of the tractor and a condition of the machine scraper. 
     
     
         17 . The electrical drive system of  claim 16  wherein when the power control system and electrical drive device operate in the empty phase and the fill/dump phase the powered axle rotates without the electrical drive device providing power and the electrical drive device operates as a generator by putting drag on an engine of the tractor by way of the powered axle to charge the battery pack; and wherein when the power control system and electrical drive device operate in the cutting/loading phase and the transport phase the power control system commands the electrical drive device to operate as a motor to provide power to the powered axle. 
     
     
         18 . The electrical drive system of  claim 17  wherein the condition of the tractor is selected from a group consisting of an actual speed of the tractor, a gear of the tractor, an output shaft speed of the tractor, an engine torque of the tractor, a calculated speed of the tractor, and an error fault of a tractor control system of the tractor. 
     
     
         19 . The electrical drive system of  claim 17  wherein a discharge from the battery pack is higher in the cutting/loading phase than the transport phase. 
     
     
         20 . The electrical drive system of  claim 1  wherein the power conditioning circuit is configured to determine that the battery pack is at a buffer and to command the electrical drive device to operate in a low-torque mode to supply only an amount of torque necessary to overcome a rolling resistance of a wheel.