System and method for operating excavator

Abstract

An excavator is provided. The excavator includes an excavating device and an excavating device drive system that powers the excavating device to move a cutting tool, where the excavating device drive system includes an electric motor and a motor controller, where the motor controller is programmed to control a speed of the excavating device drive system. The motor controller sets a speed of the digging device driving system to a predetermined digging speed according to a predetermined target power associated with a target torque generated by the electric motor. When the power transmitted to the electric motor is lower than a predetermined target power, the speed of the digging device driving system is set to a predetermined first digging speed, and the speed of the digging device driving system is set to a predetermined second digging speed to maintain the power transmitted to the electric motor at the predetermined target power.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 325,440 filed on March 30, 2022 and U.S. Provisional Patent Application No. 63 / 415,005 filed on October 11, 2022, the contents and disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0003] The field of the disclosure relates to excavators, and more particularly to excavator drive devices and associated control systems, as well as excavator mechanical devices and isolation systems. Background Art

[0004] Control System Various types of excavators include a cutting system configured to cut a desired surface, and a propulsion system configured to propel the cutting system. The cutting system is driven by a cutting drive system, and the propulsion system is driven by a propulsion drive system. In addition, the control system may also coordinate the operation of the cutting device system and the propulsion drive system.

[0005] Excavators may include, for example, chain trenchers, terrain levelers, rock drills, and underground miners. A chain trencher typically includes a trencher boom having a cutting tool mounted on a chain that moves about the boom and having a drive sprocket at one end and an idler at the other end. The chain trencher is configured to cut as the chain is propelled about the boom, moving the cutting tool through a cutter travel path driven by a cutting drive system. The chain trencher is also configured to cut as the boom moves along the ground with the entire machine driven by a machine propulsion system driven by a propulsion drive system, or as the boom moves relative to the machine chassis and the ground driven by a boom positioning system (typically including hydraulic cylinders). These combined movements form a trench.

[0006] Terrain levelers, also known as surface miners, may include cutting tools mounted on the periphery of a drum, which is a relatively long cylinder. Terrain levelers are configured to cut as the drum rotates, powered by a cutter drive system, which moves the cutting tools through a cutter travel path. Terrain levelers are also configured to cut as the drum moves along the ground with the entire machine, driven by the machine propulsion system, driven by a propulsion drive system, or as the drum moves relative to the machine chassis and the ground, driven by a drum positioning system, which typically includes hydraulic cylinders. These combined motions create a surface parallel to the axis of rotation of the drum.

[0007] An underground mining machine, also known as a continuous miner or roadheader, may include a cutting tool mounted on a rotatably driven cutting head, the cutting head mounted on a boom that is rotatably mounted on a mainframe of the mining machine. The mining machine is configured to cut while the cutting head rotates as driven by a cutter drive system to move the cutting tool through a cutter travel path. The mining machine is further configured to cut while moving the boom as driven by a boom positioning system powered by a propulsion drive system. Cutting is performed to excavate the material being mined.

[0008] These types of excavators typically include a cutter drive system, a propulsion drive system, and a control system that coordinates the operation of these systems. Most of the power required for excavation is used by the cutter drive system. The way the propulsion system is controlled affects the power used by the cutting system. Therefore, there is a relationship between the operation of the propulsion system and the power used by the cutter drive system. The material being excavated is often non-uniform. Therefore, in order to optimize the performance of the cutting system, the control system needs to be able to continuously change the operation of the propulsion drive system to compensate for changes in the excavated material.

[0009] Many excavators are self-contained mobile machines, usually with a diesel engine that powers both the cutter drive system and the propulsion drive system. To optimize production, the control system controls the operation of the propulsion drive system in a way that optimizes the performance of the cutting system. One way to optimize production is to operate the propulsion drive system in a way that extracts maximum power from the diesel engine.

[0010] The excavation process causes the force required to push the cutting tool to vary significantly. For example, when a chain trencher is excavating rock, the force required to pull the trenching chain will often vary greatly. There are several reasons for this variation. One is due to the characteristics of the rock and the characteristics of the excavation tool.

[0011] As an example, Figure 1 A common cutting tool, often called a pick, is shown being pulled in one direction by the cutter drive system and simultaneously pushed in a second direction by the propulsion drive system. The pick cuts through the material in layers, causing the cutting forces to fluctuate as the cross-section is cut through layer by layer. The force variations can be large compared to the average force. The variation in force required can vary between different types of excavators. The geometry of the cutting tool, the way the cutting tool and cutting system engage the ground, and the way the cutting structure interacts with the soil all result in variations in the force required. Therefore, the control system must have the flexibility to accommodate these variations.

[0012] In some systems, a diesel engine powers the cutter drive system by converting the potential energy in the diesel fuel into mechanical power. The engine's fuel and air system can be controlled by varying the engine's fuel and air flow to vary the engine's power output. Due to the variation in the force required to propel the cutting tool, the power required by the cutter drive system of these excavators may change faster than the engine's fuel and air system can respond. If the system is operating near the engine's capacity, the sudden increase in power required can cause the engine to stall. Automatic control of the cutter drive system, as described in US Pat. No. 4,455,770, is a known method for operating such machines at the peak power of the engine, with the control system automatically adjusting the propulsion system up to once every 1 / 1000 of a second to control the excavation process so that the power required by the cutter drive system is close to the maximum power that the engine can produce, while minimizing the possibility of engine stalling. These stand-alone machines employ a variety of known control techniques, several of which monitor the performance of the engine as an indication of the performance of the cutting system and make rapid adjustments to the propulsion system to compensate for the change in power required by the cutter drive system.

[0013] The typical configuration of a cutting machine drive system is to provide a range of operating speeds for the cutting system. Various drive systems are used to provide different operating speed ranges, each with different performance characteristics. An example is described in US7,553,258. Figure 2 is a schematic diagram of the prior art chain trencher, which is displayed in a format consistent with the rest of this disclosure. The schematic diagram includes a diesel engine and an associated engine control unit (ECU) mechanically connected to a flywheel. The cutter drive system is shown as a drive system for a trencher chain mounted on a trencher boom. Figure 2 As shown, the system is driven by the output shaft of the transmission, the input of which is connected to the output shaft of the torque converter. The torque converter is mechanically connected to the flywheel driven by the diesel engine. The propulsion drive system is shown as a separate drive system from the ground drive. Figure 2It is represented as a ground drive unit, driven by the output shaft of a hydraulic motor, which is fluidly connected to a variable displacement hydraulic pump. Although the hydraulic motor for the propulsion drive system is shown as a fixed displacement motor, it can also be a variable displacement motor. The disclosure of document US7,553,258 describes a ground drive unit consisting of a pair of crawlers, including a pair of pumps and a pair of motors. During operation of the excavator, the operator needs to select the required speed of the cutter drive system by selecting a specific gear of the transmission. The control system then monitors the engine speed (I-1) and the torque converter output speed (I-2). The control system has an output terminal O-1, which affects the control of the hydraulic pump, which controls the ground drive, propulsion drive system. The controller will have many inputs and outputs not shown in this figure, such as inputs and outputs that allow the operator to control the engine speed, such as selecting between idle and operating speeds, and control the speed of the ground drive unit to achieve steering and general speed control. Figure 1 is a simplified system diagram showing only the inputs and outputs relevant to controlling the load on the cutter drive system during digging, specifically using engine speed (same as the torque converter input speed) and torque converter output speed as feedback signals.

[0014] In order to facilitate the comparison of various cutting machine drive systems, Figure 3 Five possible operating conditions are described along with the general response of this prior art system. The responses described are intended to describe the potential response of the system to simulated load conditions and are not representative of actual operating conditions. The simulated operating characteristics are intended to demonstrate the interaction between the operating characteristics of the engine and the operating characteristics of the cutter drive system. During use, the control system affects the operation of the propulsion drive system, which in turn affects the cutter drive system. This simulation does not consider the effects of this control. The response of the entire system is complex. The following characterization is intended to provide a general description of how the system responds.

[0015] Figure 4 is a graph of a typical diesel engine showing the maximum power and torque that the engine can produce at different operating speeds. This corresponds to the following operating data at higher speeds.

[0016] Figure 5 This is an example of the working characteristics of a torque converter, reproduced from US5,337,867 Fig. 9 .

[0017] assumed Figure 2 The chain trencher has Figure 4 The torque curve describes the operating characteristics of the engine and Figure 5The curve describes the operating characteristics of the torque converter, and assuming that the cutter drive system is able to use all the power produced by the engine, the following scheme describes the operation of the system under various load conditions. Figure 3 These load conditions are illustrated by a series increase in the variable labeled "Required Output Torque." This variable is a measure of the force required to push the cutting tool. This is not intended to describe actual conditions, as the engine will be providing power to the propulsion system as well as Figure 2 The figure shows the other systems that power the parasitic loads. This also shows that the required torque is relatively constant with no short-term changes. In reality, the required torque will vary more. However, to describe the general dynamic response of the system, the required torque is described as relatively consistent. The speed of the cutting system, and how it changes with changes in the required output torque, shows the general response of the system.

[0018] Figure 3 shows the load on the cutter drive system, i.e. the required output torque. Figure 2 In the system shown, the force required to push the cutting tool will be provided by the trencher chain. The tension on the trencher chain (sometimes called line-pull) will be provided by the torque developed on the transmission output shaft. The torque developed on the transmission output shaft will be provided by the torque developed on the torque converter output shaft. Figure 3 The torque requirement mentioned in refers to the torque on the torque converter output shaft, which is a measure of the force required to push the cutting tool.

[0019] Reference Figure 3 , during time period A, at the start of the run, the required output torque (the output torque on the torque converter output shaft) will increase to 1000 ft-lbs. As the propulsion system propels the trencher boom into engagement with the trench surface, the torque load on the torque converter output shaft will increase to Figure 3 At this condition, assuming the engine is running at 2100 rpm (revolutions per minute), the engine torque output is 1040 ft-lbs. Under this condition, the torque converter characteristics can be adjusted to operate under this load condition, such as Figure 5 The operating characteristics are shown at point 8-1. In this case, the torque converter will produce 1040 ft-lbs of torque due to the torque ratio of 1.0, and the output speed is 2037 rpm due to the speed ratio of 0.97. It can be seen that the system is shown to have the ability to provide the required line pull with a slip ratio of 3% where the output shaft speed is 97% of the engine speed.

[0020] During time period B, the force required to move the trencher chain may slowly increase as the propulsion system continues to push the trencher boom and chain harder into the ground being excavated. During this time period, the torque required increases to 1150 ft-lbs as shown at point 9-2 in the figure. Assume that the torque converter operating characteristics allow it to Figure 5 If the torque is delivered to point 8-2 in the figure, the speed ratio will drop to 0.87, while the torque ratio will remain at 1.0. To produce the required torque, the engine speed will drop to 1900 rpm according to the engine torque curve. Since the speed ratio drops to 0.87, the output speed of the torque converter will drop to 1653 rpm.

[0021] As an example, the force required to move the trencher chain increases rapidly during the C period when the cutter engages with harder material. The line pull required to maintain the chain speed is equivalent to 1250 ft-lbs at the torque converter output shaft, as shown in point 9-3. The operating characteristics of the torque converter may result in the required operation under this load condition, as shown in point 8-3: The speed ratio is reduced to 0.82 and the torque ratio is increased to 1.05. At a torque ratio of 1.05, in order to produce the required torque at the output of the torque converter, the engine needs to produce 1190 ft-lbs. To produce this torque, the engine speed will drop to 1800 rpm. Since the torque converter speed ratio is 0.79, the output shaft speed will drop to approximately 1476 rpm.

[0022] like Figure 3 As shown in point 9-4 in Figure 1, during time period D, the force required to move the trencher chain may increase rapidly to the point where the line tension required to maintain the chain speed is equivalent to 1500 ft-lbs at the torque converter output shaft. The operating characteristics of the torque converter result in the desired operation under this load condition, as shown in point 8-4: the speed ratio is reduced to 0.7 and the torque ratio is increased to 1.2. In order to produce the required torque at the output of the torque converter with a torque ratio of 1.2, the engine needs to produce 1250 ft-lbs. To produce this torque, the engine speed will drop to approximately 1700 rpm. With a torque converter speed ratio of 0.70, the output shaft speed will drop to approximately 1190 rpm.

[0023] like Figure 3As shown in point 9-5 in Figure 1, during time period E, the force required to move the trencher chain may increase rapidly to the point where the line tension required to maintain the chain speed is equivalent to 1800 ft-lbs at the torque converter output shaft. The operating characteristics of the torque converter result in the required operation under this load condition, as shown in point 8-5: the speed ratio is reduced to 0.5 and the torque ratio is increased to 1.43. At a torque ratio of 1.43, in order to produce the required torque at the output of the torque converter (with a torque ratio of 1.43), the engine needs to produce 1258 ft-lbs. To produce this torque, the engine speed will drop to approximately 1600 rpm. With a torque converter speed ratio of 0.50, the output shaft speed will drop to approximately 800 rpm. Under this operating condition, Figure 4 The engine characteristics shown will result in the engine producing less horsepower even though the engine's output torque has been increased. Therefore, this is not the best operating condition for the engine.

[0024] This representative operating characteristic illustrates how a prior art drive system would react to an increase in required force as it would likely occur without compensating control of the propulsion system. This is not representative of actual data, but rather represents the expected general dynamic characteristics of this type of system when coupled to a representative engine. The operating characteristics of such a system will be determined by the design of the torque converter and generally by the specific physical properties of the torque converter which are tailored to provide the specific operating characteristics.

[0025] The operation of this prior art is expected to include a process in which an operator manually selects the operating characteristics of the ground drive system, the controller generates an output O-1, and controls the variable displacement pump to achieve the required operating characteristics of the ground drive system, usually a specific propulsion force generated by the ground drive system. As the excavation process progresses, when the system requires the cutter drive system to provide too much power, the controller can automatically adjust the displacement of the hydraulic pump by adjusting O-1 to slow down the speed of the ground drive device or reduce the propulsion force generated by the ground drive device. Various methods of controlling this system are described in document US7,553,258.

[0026] Figure 6 FIG. 4 shows how this prior art drive system responds by automatically controlling the propulsion system. In this figure, time period A and Figure 3 The same time period A shown in Figure 1 may occur after the trencher boom engages the ground, and the power required to keep the trencher chain moving increases. This will increase the load on the engine and cause the torque converter to reach Figure 5 Point 8-1 is shown. During time period B, the required torque begins to increase. Figure 6The figure shows the system response assuming that the sensor and control system detects that the output speed of the torque converter is less than 1750 rpm, and then affects the propulsion system to reduce the output torque request. During time period C, the required output torque will decrease due to the changes in the propulsion system. During time period D, the propulsion system will change, causing the required output torque to increase until the output speed of the torque converter drops to 1750 rpm again at the end of time period D. In this way, the control system can maintain system operation so that the torque converter operates within certain operating characteristics, such as Figure 5 Between the points marked 8-1 and 8-2.

[0027] Another example of related prior art is disclosed in US Pat. No. 7,930,843. Figure 7 is a schematic diagram of the prior art, which is displayed in a format consistent with the rest of this disclosure. The schematic diagram includes a diesel engine and an associated engine control unit (ECU) mechanically connected to a flywheel. The cutter drive system is shown as a drive system for a trencher chain mounted on a trencher boom. Figure 7 As shown, the system is driven by the output shaft of the hydraulic motor, which is fluidly connected to the hydraulic pump, which is mechanically connected to the flywheel driven by the diesel engine. The system can be equipped with a reduction gearbox, such as a planetary gearbox, between the fixed displacement motor (it can also be a variable displacement motor) and the trencher chain. Figure 7 The propulsion drive system and Figure 2 Similarly, it is intended to describe various possible configurations in a simplified schematic diagram. In this system, the operator selects the desired speed of the cutter drive system by selecting the displacement of a variable displacement pump controlled by a controller, which generates an output signal O-1 for controlling the pump. As the displacement increases, the speed of the hydraulic motor also increases. After the operator selects the desired speed of the cutting system, it will not generally change during the short period shown in the present disclosure to characterize the overall dynamic response characteristics of the system during operation. Although the displacement of the pump can be changed, the response time of the present system is not sufficient to achieve the change quickly, so it is impractical to change the displacement during the short period described in the present disclosure. Therefore, in the present drive device, it will be assumed that the displacement of the pump is fixed during the time period shown in the figure, so that there is generally a fixed relationship between the engine speed and the speed of the motor output shaft. During excavation, the control system monitors the engine speed I-1.

[0028] Document US Pat. No. 7,930,843 describes that the controller also monitors the output pressure I-2 of the hydraulic pump. The output O-2 of the control system affects the control of the hydraulic pump that controls the ground drive device (ie the propulsion drive system). Figure 7 is a simplified system diagram showing only the inputs and outputs relevant to controlling the load on the cutter drive system during digging, specifically using engine speed and hydraulic pump output pressure as feedback signals.

[0029] For comparison with a drive system with a torque converter, e.g. Figure 7 As shown, chain trenchers with the same engine operating characteristics and hydrostatic system for the cutter drive system can be Figure 8 For comparison purposes, it is assumed that the trencher chain is propelled by connecting to the output shaft of the gearbox, which in turn is connected to the output shaft of the fixed displacement motor. It is assumed that the operator has adjusted the displacement of the variable displacement pump so that Figure 7 The output shaft speed of the fixed displacement motor in the hydrostatic drive system is Figure 2 The output speed of the torque converter system is matched, and both are running at an engine speed of 2100rpm. Figure 3 The midpoint 9-1 is used for Figure 2 The load conditions of the system are based on the following assumptions: the engine is running at 2100 rpm and the output torque is 1040 ft-lbs, resulting in an output speed of 2037 rpm at the torque converter. To compare the overall system response, it is assumed that Figure 7 The machine's gearbox has a gear reduction device that Figure 8 The output speed of the motor is Figure 2 The output speeds of the torque converters are equal. This gear reduction is not necessary. A hydrostatic system can use a motor with a much lower output shaft speed. However, to compare possible system responses, if Figure 7 The hydrostatic system in the system has this gear reduction device, so Figure 8 At the operating condition represented by 11-1, assuming the hydraulic motor output shaft speed is 2037 rpm and the engine speed is 2100 rpm, the engine can produce 1040 ft-lbs of torque or 416 HP. For the hydrostatic system to achieve this operating condition, it must be operating at an efficiency of 93%. In fact, this is higher than the expected capability of a hydrostatic system. It is usually assumed that the operating efficiency of a hydrostatic system is between 80% and 85%. However, for this comparison, it is assumed that the hydrostatic system operates at an efficiency of 93%. Based on this assumption, the system is able to produce 997 ft-lbs of torque, which is sufficient to meet the torque requirement at this load condition. The following is a description of the possible system response to a change in operating conditions starting from the operating point labeled 11-1. The change in required torque is the same as described previously for the torque converter system, and the response of the system is described as a change in output speed. The performance characteristics of this hydrostatic system are greatly simplified. The efficiency of the system will change with changes in operating pressure and speed, so the assumed system efficiency is not a perfect representation of the system response. Figure 8 The responses described are only general indications of expected system responses.

[0030] During time period A, the torque required increases relatively slowly to the operating point labeled 11-1 above. During time period B, the torque required to maintain the trencher chain increases relatively slowly to condition 11-2, where the required torque is 1150 ft-lbs. To produce this torque, the engine speed will drop to approximately 1800 rpm, which will result in an output speed of 175 rpm and an output torque capacity of 1150 ft-lbs. The change in output speed is due to the engine's response to the increase in load. During time period C, the torque required to maintain the trencher chain increases more rapidly to condition 11-3, where the torque required is 1250 ft-lbs. To produce this torque, the engine speed will drop to approximately 160 rpm, with an output speed of 1560 rpm. At this operating point, the engine is also loaded to the point where it can provide the required torque, but its speed is pulled down to a point on the operating curve where it cannot produce the same power. Therefore, this is not the engine's optimal operating point. During time period D, the torque required to maintain the trencher chain motion increases to Condition 11-4, where the torque required is 150 ft-lbs. During this time period, an excavator equipped with a hydrostatic transmission will not be able to respond. The torque required will exceed the maximum torque of the engine and the engine will stall.

[0031] Figure 8 The operating scenario describes Figure 7 How does the prior art system in the prior art generally respond to an increase in the required force. The operation of this prior art includes: the operator manually selects the operating characteristics of the ground drive system to achieve the desired excavation process. The operator's control will cause the controller to produce an output O-2, which will control the variable displacement pump to achieve displacement to provide the desired ground drive system operating characteristics, usually a specific ground speed or propulsion force generated by the ground drive system. Figure 8 The operating scenarios shown are not intended to illustrate the operation of the propulsion system being controlled in any particular manner. In actual applications, as the excavation process progresses, the controller will automatically adjust the displacement of the hydraulic pump by adjusting the output O-2, for example, when the system requires too much power from the cutter drive system, slowing down the ground drive, which can be determined by monitoring the engine speed I-1 or the hydraulic pressure I-2. Document US7,930,843 describes various control system methods. None of these automatic control techniques are reflected in Figure 8 The operating characteristics are shown.

[0032] Figure 3 and Figure 8The operating characteristics of these two prior art drive systems are shown to illustrate how these systems provide similar performance when the engine is operating at near maximum power, but react differently when the load is increased to the maximum torque that the engine is capable of producing.

[0033] When operating near full load, systems equipped with torque converter transmissions can handle sudden increases in load by providing the required torque, but with a significantly reduced output speed.

[0034] Additionally, systems with hydrostatic transmissions can overload the engine.To optimize the performance of these variable transmission systems, control systems for the propulsion drive system have been developed in which the performance characteristics of the transmission are matched to the control characteristics of the propulsion system.

[0035] Therefore, there is a need to continuously optimize the drive system and related control systems, especially in response to advances in electric drive systems and torque converter technology.

[0036] Mechanical Arrangements Various types of excavators include a cutting system for cutting a desired surface, and a propulsion system for propelling the cutting system. For example, a chain trencher typically includes a digging chain driven around a boom. The boom can be selectively raised and lowered to dig a trench (e.g., in the earth) using the digging chain. In another example, an open pit miner includes a drum having a plurality of teeth. The drum is driven so that the drum rotates and the teeth dig into a surface (e.g., the ground).

[0037] The cutting tools of excavators, such as the digging chains of chain trenchers and the drums of surface miners, are usually driven by electric and / or mechanical motors. Figure B5 is a simplified diagram of a known mechanical device B10 for a chain trencher.

[0038] like Figure B5 As shown, for at least some known chain trenchers, the mechanical device B10 includes a head shaft B12 driven by a first rotary drive unit B14 and a second rotary drive unit B15. The rotary head shaft B12 drives the digging chain to rotate around a boom B16. In the mechanical device B10, the first and second rotary drive units B14 and B15 each include a motor B18 and a gearbox B20.

[0039] Gearbox B20 Figure B5The arrangement shown supports the head shaft B12. Specifically, the pilot section B22 of each gearbox B20 engages the main frame B24 of the chain opener. The head shaft B12 is then supported by bearings B26 in the gearbox B20. In this arrangement, the components within the gearbox B20 rotate relative to the main frame B24, which drives the head shaft B12 to rotate. In addition, the torque arm B30 fixes the gearbox B20 in place, preventing the gearbox B20 from rotating in the opposite direction relative to the main frame B24. In this arrangement, the bearings B26 in the gearbox B20 bear all radial loads caused by the cutting action. In addition, this arrangement relies on the clearance between the pilot section of the main frame B24 and the pilot section B22 of each gearbox B20 to prevent static uncertain loads (i.e., more than two bearings on the shaft). Therefore, in this arrangement, the bearing loads may be unpredictable.

[0040] Figure B6 is a simplified diagram of another known mechanism B40 for a chain trencher. The mechanism B40 does not include a gearbox. Instead, a motor B42 (e.g., a slow hydraulic motor) is mounted directly on a head shaft B44. The motor B42 is supported by the head shaft B44 via a first bearing B46. In addition, the head shaft B44 is supported by a main frame B48 via a second bearing B50. A torque arm B52 is connected to the motor B42 to prevent the motor B42 from rotating in the opposite direction. It is worth noting that since a gearbox is not included, this arrangement generally requires a motor that can produce a relatively high torque.

[0041] Therefore, there is a need for alternative mechanical devices that avoid at least some of the problems associated with known mechanical devices. For example, Figure B5 The mechanical device requires a gearbox to support the head shaft. In addition, Figure B6 Low torque motors cannot be used in mechanical devices.

[0042] Additionally, in at least some known surface miner excavators, the motor for driving the drum is located inside the drum, which may make access to the motor (e.g., for repair and / or replacement operations) relatively difficult. Additionally, because the motor is located inside the drum, the motor may be difficult to cool and relatively close to the material being cut by the excavator. Additionally, the cutting tool of at least some known excavators is driven using a single motor and a single gearbox. This requires a single motor to generate all of the power required to operate the cutting tool, rather than using multiple motors to generate the power. Additionally, if one of the single motor and the single gearbox fails, the cutting tool will not function properly.

[0043] Therefore, there is also a need for an alternative mechanical device that can easily access the motor. In addition, there is also a need for an alternative mechanical device, including multiple motors and / or gearboxes, to improve the operability and reliability of the excavator.

[0044] Isolation system Various types of excavators include a cutting system for cutting a desired surface, and a propulsion system for propelling the cutting system. For example, a chain trencher typically includes a digging chain driven around a boom. The boom can be selectively raised and lowered to dig a trench (e.g., in the earth) using the digging chain. In another example, an open pit miner includes a drum having a plurality of teeth. The drum is driven so that the drum rotates and the teeth dig into a surface (e.g., the ground).

[0045] The cutting tools of an excavator, such as the digging chain of a chain trencher and the drum of a surface miner, are typically driven by electrical and / or mechanical motors. In at least some known systems, the motor is coupled to the cutting tool and is also subject to vibrations and / or oscillations generated or experienced by the cutting tool. For example, in a chain trencher or surface miner, the excavator frame may experience significant vibrations and / or oscillations during operation. These vibrations and / or oscillations may be caused, for example, by the cutting tool striking the excavated material and the material tumbling over the cutting tool.

[0046] In some known systems, the motor may also be subject to vibrations and / or oscillations generated by other parts of the excavator (such as the excavator's diesel engine). These vibrations and / or oscillations may affect the operation of the motor and may eventually cause damage or failure of the motor.

[0047] Therefore, there is a need to isolate the motor of the excavator from the vibrations and / or vibrations generated by other parts of the excavator. Summary of the invention

[0048] In one embodiment, an excavator is provided. The excavator includes an excavation device and an excavation device drive system, wherein a plurality of cutting tools are mounted on the excavation device, and the excavation device drive system provides power to the excavation device to move at least one of the plurality of cutting tools through a cutting machine travel path. The excavation device drive system includes an electric motor and a motor controller, wherein the electric motor is powered by a power source. The motor controller is programmed to control the speed of the excavation device drive system through a control algorithm, wherein the control algorithm, when executed by the motor controller, causes the motor controller to set the speed of the excavation device drive system to a predetermined excavation speed according to a predetermined target power, and the predetermined target power is associated with a target torque generated by the electric motor. When the power transmitted to the electric motor is lower than the predetermined target power, the speed of the excavation device drive system is set to a predetermined first excavation speed, and the speed of the excavation device drive system is set to a predetermined second excavation speed that is less than the predetermined first excavation speed to maintain the power transmitted to the electric motor at the predetermined target power and is associated with an increase in the target torque generated by the electric motor. When the first force required to push at least one of the plurality of cutting tools exceeds the second force that the excavation device drive system can generate when operating at the predetermined first excavation speed at the predetermined target power, the speed of the excavation device drive system is set to the predetermined second excavation speed.

[0049] In another embodiment, an excavator is provided. The excavator includes a diesel engine having an engine control unit (ECU) that controls and monitors a fuel system and an air intake system that provide diesel and combustion air to the diesel engine, wherein the ECU calculates an engine load parameter based at least in part on the amount of fuel and the air flow. The excavator also includes an active cutting system and a power transmission that transmits power from the diesel engine to the active cutting system at a variable operating speed, wherein the variable operating speed is based on an operating parameter that affects a variable torque and speed characteristic of the power transmission. The excavator also includes a propulsion system that propels the active cutting system during excavation, and a control system that controls the propulsion system based on the variable operating speed of the power transmission, wherein the control system controls the operating parameter of the power transmission based on the engine load parameter.

[0050] In another embodiment, a mechanical device for an excavator is provided, the mechanical device including a cutting tool, a head shaft coupled to the cutting tool and defining a longitudinal axis, a gearbox coupled to the head shaft so that the head shaft supports the gearbox, and a motor coupled to the gearbox, wherein the motor is offset from the longitudinal axis of the head shaft and the motor is configured to drive the head shaft and the cutting tool to rotate through the gearbox.

[0051] In another embodiment, a mechanical device for an excavator is provided, the mechanical device comprising a cutting tool, a head shaft coupled to the cutting tool, at least one gearbox coupled to the head shaft so that the head shaft supports the gearbox, and a plurality of motors, wherein the plurality of motors are configured to drive the head shaft and the cutting tool to rotate, and at least one of the plurality of motors is coupled to at least one gearbox. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic diagram of a known cutting tool; Figure 2 is a schematic diagram of a known chain trencher including a torque converter for a cutter drive; Figure 3 yes Figure 2 The operating state diagram of the chain opener shown; Figure 4 It is the operating curve diagram of the diesel engine; Figure 5 is an example diagram of the torque converter operating characteristics; Figure 6 yes Figure 2 The operating state diagram of the chain trencher shown in the figure is under the automatic control of the propulsion system; Figure 7 is a schematic diagram of a known chain trencher including a hydrostatic transmission for driving the cutter; Figure 8 yes Figure 7 The operating state diagram of the chain opener shown; Fig. 9 is a simplified schematic diagram of a first embodiment of the present disclosure having an electric transmission for a cutting machine drive; Fig.10 yes Fig. 9 The operating state diagram of the chain opener shown; Fig.11 yes Fig. 9 Chain opener shown with Figure 2 and Figure 7 The operation status comparison diagram of the chain opener shown; Fig.12 shows that when the control system automatically controls the propulsion drive system, Fig. 9 How the systems in the system respond; Fig.13 is a flow chart of one embodiment of a control algorithm according to the present disclosure; Fig.14 is a simplified schematic diagram of a second embodiment of the present disclosure with electric transmission for cutter drive and propulsion drive; Fig.15is a simplified schematic diagram of a third embodiment of the present disclosure, in which a mechanical transmission device has a controllable torque converter for a cutting machine drive; Fig.16 is a flow chart of an example method of operating an excavator according to the present disclosure; Figure B1 is a perspective view of a chain trencher, which is an example of an excavator according to the present disclosure; Figure B2 yes Figure B1 A side view of the chain trencher shown with the boom in the raised position; Figure B3 yes Figure B1 A side view of the chain trencher shown with the boom in the lowered position; Figure B4 is along Figure B2 A cross-sectional view of the chain trencher taken along line B4-B4 shown; Figure B5 is a simplified diagram of a known excavator mechanism; Figure B6 is a simplified diagram of another known excavator mechanism; Figure B7 is a simplified diagram of one embodiment of a chain trencher mechanism according to the present disclosure; Figure B8 yes Figure B8 A partial enlarged view of Figure B9 It is another embodiment of the chain trencher mechanical device, including a dual motor drive device; Figure B10 is an embodiment of a mechanical device for driving an open-pit mining machine; Figure B11 is a perspective view of one embodiment of an open pit mining machine; Figure B12 yes Figure B11 A side view of the surface miner shown; Figure B13 yes Figure B11 A top view of the surface miner shown; Figure B14 yes Figure B11 A front perspective view of the surface miner mechanism shown; Figure B15 yes Figure B14 a rear perspective view of the mechanism shown; Figure B16 is a simplified diagram of one embodiment of a mechanical device that may be used with a surface miner; Figure B17 is a simplified diagram of one embodiment of a mechanical device that may be used with a chain trencher; Figure C1 is a perspective view of one embodiment of an open pit mining machine; Figure C2 yes Figure C1 A side view of the surface miner shown; Figure C3 yes Figure C1 A top view of the surface miner shown; Figure C4 is along Figure C3 A cross-sectional view of the open-pit mining machine taken along line C4-C4 is shown; Figure C5 It is available with Figure C1 A simplified schematic diagram of an engine generator bracket for use with the surface mining machine shown; Figure C6 yes Figure C5 a perspective view of the illustrated engine generator mount; and Figure C7 yes Figure C5 Another simplified schematic diagram of the engine generator bracket shown.

[0053] Corresponding reference characters indicate corresponding parts throughout the drawings. DETAILED DESCRIPTION

[0054] Control System Fig. 9 is a simplified schematic diagram of a first embodiment of the present disclosure having an electromechanical transmission (EMT) for a cutter drive system as the drive system for a trencher chain mounted on a trencher boom.

[0055] Although at least some embodiments described herein are described in the context of a chain trencher, those skilled in the art will appreciate that the systems and methods described herein may also be implemented in other excavation machines (eg, terrain levelers, underground mining machines, etc.).

[0056] Fig. 9 The cutter drive system shown has a gearbox, the output end of which is connected to the trencher boom. This connection connects the output shaft of the gearbox to the drive sprocket around which the trencher chain is wound, and the drive sprocket is rotated by the gearbox output shaft, thereby pulling the trencher chain to rotate around the trencher boom, converting the torque transmitted by the gearbox output shaft into a linear force, that is, a force that pulls the chain along the trencher boom.

[0057] The input shaft of the gearbox is connected to the output shaft of the electric motor. In one embodiment, this is a permanent magnet synchronous motor, which is electrically connected to a motor controller and a frequency converter. Other suitable types of motors may also be used, such as permanent magnet asynchronous motors or switched reluctance motors. For example, switched reluctance motors are relatively simple from a mechanical point of view and may be more reliable than other types of motors.

[0058] The motor controller and the inverter are electrically connected to the generator. The motor controller and the inverter receive the electrical energy generated by the generator in the form of direct current, in one embodiment, the DC voltage is 650 volts, or in the range of 550 to 750 volts, and apply current to a series of coils of the motor to generate a rotating magnetic field. The motor controller affects the speed of the rotating magnetic field, thereby affecting the speed of the motor output shaft. At the same time, the motor controller also monitors the current level and output speed of the motor to evaluate the power transmitted to the motor. The motor controller can be programmed to maintain a stable output speed and / or transmit a target power or a set power. With the help of existing sensing and control electronics on the market, the motor controller is able to make adjustments in a very short time (e.g., milliseconds) to affect the rotation speed of the magnetic field and adjust the current level applied to the coils inside the motor, thereby affecting the output speed and transmitted power of the motor.

[0059] exist Fig. 9 In some embodiments, the generator is powered by a diesel engine. However, it will be appreciated by those skilled in the art that the generator (and the motor controller and motor) may be powered by any suitable power source. For example, in some embodiments, power is provided by one or more energy storage devices (such as a battery system), or by energized power lines (such as as part of a tram system powered by overhead power lines).

[0060] The main components of the generator, motor, power electronics, and electromechanical transmission form a complex system. The dynamic response of this system, and how it reacts to changes in the torque required to drive the excavator cutting system (such as to drive the trencher chain around the trencher boom), will be affected by several factors. These factors can include, for example, the type of cutting tool, the type of ground conditions, and the amount of power available to power the cutting system, which may be affected by the ambient temperature (for example, in hotter ambient conditions, the system will require more power for cooling, which will reduce the available power to the cutting system drive).

[0061] In one embodiment, the control logic of the motor controller and power electronics will include operating parameters such as the desired operating speed as a primary control parameter and the target maximum power as a secondary control parameter. In no-load or low-load conditions, the motor controller can adjust the current delivered to the motor to control the rotational speed so that it is equal to the desired operating speed. The no-load condition refers to the trencher chain moving on the trencher boom without the cutters on the chain contacting any material. In this case, the cutter system requires a certain amount of power to rotate the trencher chain, but this is much less than the power required during the excavation process because the cutters are already in contact with the material being excavated. In this no-load condition, the motor controller will adjust the time that the current is applied to the motor coils to achieve the desired magnetic field rotation speed to achieve the desired output speed of the motor.

[0062] The dynamic characteristics of the powertrain system, and in certain embodiments the permanent magnet synchronous motor, are determined by the motor controller, also referred to as a variable frequency drive (VFD) in this embodiment. There is no mechanical connection between the engine and the cutter drive system. Therefore, the operating characteristics of the engine do not affect the dynamic operating characteristics of the cutter drive system. The controller is able to adjust how the current is applied to the various components of the motor to affect the speed of the rotating magnetic field, affect the output speed of the motor, and control the current level applied to the various components of the motor to affect the torque produced by the motor. These adjustments can be made quickly enough to cope with typical changes in the force required to push the cutting tool, thereby maintaining a stable maximum power consumption. The overall efficiency of the system, including the generator, inverter and motor, will remain relatively stable when the speed and torque vary significantly.

[0063] In some embodiments, if the torque required to propel the cutting tool increases to a point where the current required to produce that torque exceeds the capacity of the motor, the motor controller will continue to reduce the speed and maintain the torque at that maximum torque.

[0064] It will be explained below how the performance of this powertrain responds to changes in conditions similar to those of the torque converter type and hydrostatic type systems described previously.

[0065] Fig. 9 The system also includes a propulsion system as a ground drive system having a variable displacement hydraulic pump and fixed displacement motor. The system controls the movement of the trencher boom in the excavated material. The propulsion system can also be a drive device other than the ground drive system for moving the trencher boom. Fig. 9 The ground drive system described in detail in is representative of a general propulsion system.

[0066] The controller may be connected to a number of other devices (not shown) to control the speed and direction of travel of the propulsion system. The controller may also be connected to one or more input devices that allow the operator to control the speed of the engine. Again, these devices are not illustrated in the figure. Fig. 9 The inputs and outputs that control the mining process are shown.

[0067] In one embodiment, Fig. 9 The operation of the system shown includes the following processes / steps of the trencher: 1) The operator will position the machine and its boom for excavation. The operator will then adjust the speed of the cutter drive system. This is controlled by the output O-1 communication sent by the controller to the motor controller, through which the operator selects the desired speed of the cutter system. The O-1 communication signal also contains information defining other operating parameters of the cutter drive system, such as the target power. As mentioned above, in the initial no-load state, the target speed will be the primary control parameter; 2) Once the cutter drive system is running at the desired speed, the operator will then operate a separate control causing the control system to send a signal O-2 to the variable displacement hydraulic pump to affect the ground drive system. This is a specific type of propulsion system shown in this embodiment. Other types of propulsion systems are also common, including actuators that can raise or lower the trencher suspension. Although Fig. 9 A ground drive system is shown as the propulsion system, but the present disclosure is intended to be generally applicable to various types of propulsion systems.

[0068] 3) Once the propulsion system is activated, the trencher chain will begin to engage with the material being excavated and the power required to keep the trencher chain moving will increase.

[0069] For comparison with prior art systems, the following possible operating conditions are based on the following assumptions: engines with the same operating characteristics are used; Fig. 9 The machine's gearbox has a gear reducer that causes the motor's output speed to be equal to Figure 2 The torque converter and Figure 7 The output speed of the hydraulic motor; the efficiency of the generator, inverter and motor results in a system performance at the first operating point equivalent to that of the torque converter system and the hydrostatic system described above. Similar to the assumptions made previously for the hydrostatic system, this assumed efficiency is not necessarily true in reality and is provided for comparison with the other two systems. If the overall system efficiency of the electromechanical transmission is 93%, the following operating characteristics are expected.

[0070] According to the above assumptions, Fig. 9 Possible system performance conditions such as Fig.10 shown.

[0071] During the first period A, at the start of the run, the line tension required to maintain the chain speed may gradually increase to a level equivalent to 1000 ft-lbs on the motor output shaft. As the propulsion system moves the trencher boom into engagement with the trench wall, the load on the motor output shaft increases to Fig.10 At the point marked as 12-1, the output speed is 2037 rpm.

[0072] During time period B, the force required to push the trencher chain may slowly increase as the propulsion system continues to push the trencher boom and chain toward the ground being excavated. During this time, the required torque is shown at point 12-2 as increasing to 1150 ft-lbs. Assuming a system efficiency of 93% and an engine output of 416 hp, the motor is able to maintain an output speed of 1765 rpm at the required load. The dynamic response of the electromechanical transmission to the increase in required torque will allow the system to adjust its operation to provide this output speed while providing the required torque in a very short response time.

[0073] Since the power used at this operating point is still 416 hp, the load on the engine will remain the same and the engine can run at the same speed as at point 12-1 load condition. The engine speed can also be lower. In the electromechanical transmission of this embodiment, there is no clear relationship between engine speed and motor output speed. The power produced by the engine remains the same at different engine speeds. Regardless of the output speed, the engine can provide the required power and the power electronics of the electromechanical transmission can compensate.

[0074] For example, during time period C, as the cutter encounters harder material, the force required to move the trencher chain increases rapidly. This is shown as point 12-3, where the line tension required to maintain the chain speed is equivalent to 1250 ft-lbs at the motor output shaft. Assuming a system efficiency of 93% and an engine input power of 416 hp, the motor output speed can be maintained at 1624 rpm at the required load.

[0075] Since the power used at this operating point is still 416 hp, the load on the engine in terms of the power required is the same. As mentioned above, the engine speed can be different, provided that the engine can provide the required power regardless of its output speed and the power electronics of the electromechanical transmission can compensate.

[0076] During time period D, the force required to move the trencher chain may increase rapidly to the point where the line tension required to maintain the chain speed is equivalent to 1500 ft-lbs on the electric motor output shaft, e.g. Fig.10Assuming a system efficiency of 93% and an engine input of 416 hp, the electric motor is able to maintain an output speed of 1353 rpm at the required load.

[0077] Since the power used at this operating point is still 416 hp, the load on the engine in terms of the power required is the same. As mentioned above, the engine speed can be different, provided that the engine can provide the required power regardless of its output speed and the power electronics of the electromechanical transmission can compensate.

[0078] During time period E, the force required to move the trencher chain may increase rapidly to the point where the line tension required to maintain the chain speed is equivalent to 1800 ft-lbs on the electric motor output shaft, e.g. Fig.10 Assuming a system efficiency of 93% and an engine input of 416 hp, the electric motor is able to maintain an output speed of 1128 rpm at the required load.

[0079] Since the power used at this operating point is still 416 hp, the load on the engine in terms of the power required is the same. As mentioned above, the engine speed can be different, provided that the engine can provide the required power regardless of its output speed and the power electronics of the electromechanical transmission can compensate.

[0080] These operating characteristics illustrate one of the advantages of an electric drivetrain system, which is the ability to control the torque and speed of the motor output independently of the torque applied to the engine, and the system has relatively stable operating efficiency over the entire range of operating conditions. These theoretical operating characteristics illustrate the response of the system in a steady-state operating state after adapting to different torque requirements under different operating conditions. These operating characteristics are not intended to characterize the dynamic response of various drive systems, nor are they intended to characterize the effects of load fluctuations on engine operation.

[0081] For ease of comparison, Fig.11 Will Figure 3 , Figure 8 and Fig.10The operating characteristics of the three different systems shown are combined into one graph. The graph shows that the operating characteristics of the systems are approximately the same at load conditions 13-1 and 13-2. However, as the required load increases, the comparison changes. At load conditions characterized by 13-3 and 13-4, these performance curves show that a torque converter transmission can theoretically meet the load requirements, but at a reduced speed due to the inherent reduced speed ratio of the torque converter. As a result, more slip occurs under these operating conditions, resulting in less efficient power transmission and heating of the torque converter. In addition, the hydrostatic transmission may overload the engine and fail to meet the required load.

[0082] It is noteworthy that the electromechanical transmission is able to accommodate the required increase in load by reducing speed while maintaining maximum power consumption. The speed reduction of the electromechanical transmission is less than that of the torque converter transmission because the electromechanical system has a stable system efficiency.

[0083] This illustrates one advantage of electromechanical transmissions, which is the ability to adapt to changes in load, providing lower speeds and higher torque than conventional torque converter-based or hydrostatic systems. Fig.11 The example in shows the initial operating point, where the system is utilizing full power at 2037 rpm and requires 1000 ft-lbs of torque. Using a hydrostatic system, if the required torque increases by 1.5 times to 15,000 ft-lbs, the engine will stall. If a torque converter system is used, the speed is expected to drop to 1190 rpm, which is 58% of the initial state. This is not an ideal operating state because the torque converter will generate too much waste heat. Using an electromechanical system, the speed is expected to drop to 1353 rpm, which is 66% of the initial state.

[0084] Since there is no mechanical connection between the engine and the cutter drive system in an electromechanical transmission, the engine can run at its optimum operating condition. As a result, the electromechanical transmission can always maintain a stable power transmission efficiency.

[0085] for Fig. 9The electric mechanical transmission shown, as previously described, has no mechanical connection between the engine and the cutter drive system. The motor controller contains logic that affects the dynamic response characteristics of the cutter drive system. In one embodiment, the motor controller logic includes a set target motor speed and a target motor output power. Taking the above operating characteristics as an example, the motor controller can define the target motor speed as 2037 rpm. In the previous operating characteristics example, it was assumed that the operator selected a target speed of 2037 rpm, so it was equivalent to the operation of other systems. In this example, the second operating parameter, the target power of the cutter drive system, is assumed to be 416 hp. This is unrealistic because the maximum power of the engine is assumed to be 416 hp. In reality, part of the engine power is needed to operate the propulsion drive system, and part of the power is needed for additional loads, such as the cooling system. Therefore, Figure 3 , Figure 8 , Fig.10 and Fig.11 The diagrams are not intended to illustrate expected excavator performance. They are only intended to illustrate how the system's operating characteristics compare to other systems under simulated conditions. Additionally, these simulated load conditions assume that the control system does not automatically adjust the propulsion drive system.

[0086] During operation, it is expected that the system will include a process whereby the operator selects the operating characteristics of the propulsion drive system, e.g. Fig. 9 The ground drive system shown. The controller will generate an output O-2 which will control the variable displacement pump to a displacement that provides the desired operating characteristics of the ground drive system, typically a specific thrust or a specific speed generated by the ground drive system. During excavation, when the system requires too much power from the cutter drive system, the controller can automatically adjust the displacement of the hydraulic pump by adjusting O-2 to slow down the speed of the ground drive system or reduce the thrust generated by the ground drive system.

[0087] Fig.12 shows that when the control system automatically controls the propulsion drive system, Fig. 914-2. The expected operating curve for the first set of operating parameters has a first power level starting at an output speed of 2037 rpm. The desired output torque starts at point 14-1 and slowly increases toward point 14-2. This increase may be due to the propulsion drive system generating an increasing force to push the cutting tool toward the excavated material. Another operating parameter for the first set of operating parameters is defined as a minimum speed of 1750 rpm. As the desired output torque increases from point 14-1 to point 14-2, the motor controller reduces the output speed to maintain the first power until the output speed drops to the minimum speed. At this point, the propulsion drive system will adjust to reduce the desired output torque. In this example, once the output speed reaches a predetermined speed, such as 2100 rpm, the propulsion drive system will be controlled again to cause the cutting tool to cut the material more vigorously and the desired output torque will increase again. The operating curve describes a situation where the desired output torque fluctuates between 700 ft-lbs and 1000 ft-lbs. The first set of operating parameters includes the first cutter drive system power level, a minimum speed of 1750 rpm, and a maximum speed of 2100 rpm.

[0088] Fig.12 A second set of operating curves is also described in , which set of operating parameters includes a second power level (a higher power level than the first power level), the same minimum speed of 1750 rpm, and the same maximum speed of 2100 rpm. Under the second set of operating parameters, as the required output torque increases from point 14-1 to point 14-2, the speed decreases at a slower rate because the control system allows the cutter drive system to consume more power. Under the second set of operating parameters, the speed does not drop to 1750 rpm until the output torque is higher than the maximum torque under the first set of operating parameters. At point 14-2, the operation of the propulsion control system is affected, causing the required torque to decrease. As the motor controller makes adjustments to maintain a constant power consumption, the output speed increases. Under the second set of operating parameters, the output torque of the system fluctuates between 1000 ft-lbs and 1250 ft-lbs. The average output torque required for the second set of operating parameters is higher than the average output torque required for the first set of operating parameters.

[0089] The area under the required output torque curve is proportional to the power required by the cutter drive system. Fig.12 By comparing the required output torque curve for the first power level and the required output torque curve for the second power level, it is shown that the power required by the cutting machine drive system is affected by the operating parameters set for the control system.

[0090] Fig. 9The engine in the system shown includes an ECU, or engine control unit. The ECU generates data to calculate the average power load on the engine based on various operating parameters such as average fuel flow and air flow. This calculated data can be used to control the excavator in a new way. One way to optimize the productivity of the machine is to operate the machine in a way that automatically adjusts the operating parameters so that the machine runs at an average power as close to 100% as possible. The average engine power will react slower than the instantaneous power consumption of the excavation motor, so there is an opportunity to use both the instantaneous power consumption of the excavation motor and the average engine power in the control algorithm to automatically optimize the performance of the excavator.

[0091] Fig.13 One embodiment of a control algorithm designed to provide this functionality is shown: Starting at an initial operating point 13-1, the operator initiates the excavation process by selecting an operating speed for the cutter drive system and defining a set of initial operating parameters. The operating speed of the cutter drive system will be affected by the type of cutting tool installed on the active cutting system and the type of excavated material. The operator will then activate the propulsion system based on the initial operating parameters to begin excavation. For example, a chain trencher (e.g., Fig. 9 The initial operating parameter of the propulsion system (as shown) can be the propulsion pressure of the ground drive system. This parameter is the pressure generated by the variable displacement hydraulic pump, applied to the fixed displacement hydraulic motor to generate the propulsion force that pushes the boom and chain of the trencher to engage the material being excavated with a set, controllable force. This parameter is controlled by output O-2, which is sent by the controller to the variable displacement hydraulic pump.

[0092] A set of operating parameters of the cutting machine drive system may include a first power level, such as in reference Fig.12 As explained in the first power level.

[0093] The control process of 13-2 illustrates the control of a propulsion system that causes the required torque to fluctuate between a maximum value and a minimum value through several cycles. This is intended to illustrate the conventional or typical control of a chain trencher. In some prior art, such control is referenced to the engine speed and / or the output speed of the torque converter. Fig. 9 The described system uses an electromechanical transmission and there is no clear correlation between the engine speed and the motor speed. When using a permanent magnet synchronous motor and the power electronics of the electromechanical transmission, Fig. 9 The control system is shown with a sensor that measures the speed of the motor as input 1-2. At step 13-2, the control system automatically limits the propulsion system whenever the speed is below a predetermined speed. The propulsion system can be adjusted in thousandths of a second, in other words, the propulsion system can be adjusted hundreds of times per second. The system can operate in this mode for a period of time, such as one second, two seconds, or more.

[0094] The control process also includes step 13-3, in which the control system monitors power level data generated by the ECU during the period and contained in the data stream labeled I-1. The controller monitors input signal I-1, which contains engine power data calculated by the ECU based on the fuel and air systems and transmitted as part of an industry standard CAN message. The controller monitors the power level for a period of time, which can be one second or ten seconds. The specific period of time is not important, but it is longer than the period of time during which the control system automatically limits the propulsion system.

[0095] In the control process of 13-4, the controller will consider the average power level data, and if the average power level is less than the required threshold, such as less than 95%, the system will enter the process of 13-4b. In this step, the control system will change the operating parameters to increase the average power. For example, the power level can be adjusted to Fig.14 A second power level is shown, where the power to the cutter drive system is increased to a second, higher power level, which is expected to result in an increase in the power drawn from the engine.

[0096] After the control flow 13-4b changes the operating parameter, the process will return to step 13-2 and the machine will run for a period of time, during which the average power level is again determined.

[0097] If the average power is not less than 95% in step 13-4a, the system proceeds to step 13-4c. If the power level is greater than 100% in this step, the system proceeds to step 13-4d, in which the system automatically adjusts the operating parameters of the system to reduce the average engine power.

[0098] Step 13-2 describes the process by which the system automatically limits the propulsion system based on measurements of the cutter drive system operation. If the cutting system is operating at a speed below the initial operating speed, or below a certain percentage of the initial operating speed, the propulsion system is limited. Figure 2 , Figure 7 and Fig. 9 The system is shown as a hydraulic drive system.

[0099] However, the propulsion system can also be driven by a separate electromechanical system, e.g. Fig.14 As shown, the diagram shows Fig. 9 Another embodiment of the system shown in FIG. 1 wherein the propulsion system comprises a ground drive with an electromechanical transmission. The system is operated / controlled in the same manner as Fig. 9 The systems will operate / control in a very similar manner, except that Output 2 (O-2 signal) will be configured to control the power electronics of the propulsion drive system electromechanical transmission. Fig.14 A separate generator is shown to power the motor controller / inverter for the ground drive. The generator is shown in dashed lines to illustrate that this may be a separate generator or the power may come from the same generator connected to the motor controller / inverter for the cutter drive system.

[0100] In some embodiments, the cutter system (e.g., the speed of the chain) reacts faster than the propulsion system (e.g., the speed of the tracks that propel the machine), so when the machine changes the speed of the propulsion system, there will be a transient slowdown. In addition, the speed of the cutter system can also be adjusted manually. This is caused by the faster reaction speed of the VFD relative to the swashplate of the hydraulic system. There may be several transients in the cutter system, and the VFD can react to the transients faster than the hydraulic system.

[0101] Additionally, in some embodiments, there is an averaging filter between the propulsion system's reaction and the cutter system's deceleration. When the chain slows down, it reduces the propulsion system's average speed, but the chain reacts faster than the propulsion system. This feedback loop will generally stabilize when the average speed of the track is fairly close to the commanded rate of change, but there will be some drift (e.g., a commanded chain speed of 35 rpm might result in an average operating speed of 32 rpm).

[0102] Slowdowns occur relatively infrequently when cutting homogeneous materials. Momentary slowdowns typically occur more frequently when transitioning between materials causes the machine to adapt quickly. As mentioned above, VFDs allow the chain speed to react faster than the track speed, which can cause the chain to slow down quickly as it encounters new material and finds a new speed to approach the commanded chain speed. In this case, the commanded track speed may be at a standstill. To get the track moving again, the chain speed can be reduced, allowing the track to push the chain more aggressively and maintain momentum on the chain.

[0103] Fig.13 The control algorithm shown is described for controlling an electromechanical drive. The control algorithm can also be applied to Fig.15 Another system is shown in which the cutter drive has a variable torque converter. The variable torque converter can be a torque converter with controllable stator pitch or bypass clutch performance. This type of torque converter is described in US9,689,492 and US10,118,624, which are incorporated herein by reference. The operation of this system is similar to Fig.13Similarly, the operating parameters of the torque converter can be automatically adjusted. In this system, the sensor can measure the output speed of the torque converter at input 2I-2. The controller will use this signal to control the ground drive system. The ECU will communicate with the controller through input 1 (I-1). This includes information about the engine power. The operating parameters of the torque converter will be controlled by output 1, O-1. Fig.15 In an embodiment of the present invention, the engine power (calculated by the ECU) can be used as a variable to automatically change the torque converter operating parameters to improve the performance of the engine.

[0104] Fig.16 is a flow chart of an example method of operating an excavator, which method may be used in conjunction with other embodiments described herein.

[0105] Mechanical device Figure B1 is a perspective view of an example excavator B100 , here a chain trencher, that may include at least some of the embodiments described herein. Figure B2 yes Figure B1 A side view of an excavator B100 is shown in FIG. 1 , wherein the boom B102 is in a raised position; Figure B3 yes Figure B1 A side view of an excavator B100 is shown in FIG. 1 , with the boom B102 in a lowered position. Figure B4 It is the excavator B100 along the B4-B4 line (such as Figure B2 ) as shown.

[0106] Now we will introduce Figures B1-B4 The mechanism between the gearbox and the head shaft in the excavator shown.

[0107] Figure B7 is a simplified diagram of one embodiment of a mechanical device B200 of a chain trencher according to the present disclosure. Figure B8 yes Figure B7 An enlarged view of a portion of the mechanical device B200 is shown in FIG.

[0108] like Figure B7 and B8 As shown, the mechanical device B200 includes a head shaft B202 driven by a rotary drive unit B204. The rotary head shaft B202 drives a digging chain around a boom B206 (e.g., boom B102). In the mechanical device B200, the rotary drive unit B204 includes a motor B208 and a gearbox B210. The motor B208 can be any type of motor suitable for driving the head shaft B202 through the gearbox B210. For example, in some embodiments, the motor B208 can be an electric motor. In other embodiments, the motor B208 can be a hydraulic motor.

[0109] In the mechanical device B200, the head shaft B202 is mounted on the main frame B212 through the first bearing B214. It is worth noting that, compared with the mechanical device B10 (such as Figure B5 Unlike the main frame B212, the gearbox B210 is not directly connected to the main frame B212. In addition, the gearbox B210 does not support the head shaft B202. Figure B7 and B8 In the embodiment of the present invention, the head shaft B202 supports the gearbox B210. That is, the output of the gearbox B210 is a hollow shaft (i.e., a tube), which is mounted on the head shaft B202 through a seal and a spline connection. In addition, the head shaft B202 supports the gearbox B210 through a second bearing B216. The torque arm B218 fixes the gearbox B210 in place and prevents the gearbox B210 from rotating in the opposite direction relative to the main frame B212.

[0110] Figure B9 It is another embodiment of the chain opener mechanism B300.

[0111] The mechanical device B300 includes a head shaft B302 driven by a first rotary drive unit B304 and a second rotary drive unit B305. The rotary head shaft B302 drives the digging chain to rotate around a boom B306 (such as the boom B102). The first and second rotary drive units B304 and B306 are located on opposite sides of the boom B306. In the mechanical device B300, the first rotary drive unit B304 includes a first motor B308 and a first gearbox B310, and the second rotary drive unit B305 includes a second motor B309 and a second gearbox B310.

[0112] The first and second motors B308 and B309 may be any type of motor suitable for driving the head shaft B302 through the first and second gearboxes B310 and B311. For example, in some embodiments, at least one of the first and second motors B308 and B309 may be an electric motor. In other embodiments, at least one of the first and second motors B308 and B309 may be a hydraulic motor.

[0113] In the mechanical device B300, the head shaft B302 is mounted on the main frame B312 through the first bearing B314. Figure B7 and B8As shown in the figure, the head shaft B302 supports the first and second gearboxes B310 and B311. That is, the output ends of the first and second gearboxes B310 and B311 are hollow shafts (i.e., tubes), which are mounted on the head shaft B202 through seals and spline connections. In addition, the head shaft B302 supports the first gearbox B310 through the second bearing B316 and supports the second gearbox B311 through the third bearing B317. The first torque arm B318 fixes the first gearbox B310 in place and prevents the first gearbox B310 from rotating in reverse relative to the main frame B312. Similarly, the second torque arm B319 fixes the second gearbox B311 in place and prevents the second gearbox B311 from rotating in reverse relative to the main frame B312.

[0114] Figure B10 is a simplified diagram of one embodiment of a mechanical device B400 for a surface miner according to the present disclosure.

[0115] like Figure B10 As shown, the mechanical device B400 includes a head shaft B402 driven by a rotation drive unit B404. The head shaft B402 is connected to a roller B406, so that the driven rotation of the head shaft B402 also causes the roller B406 to rotate. The head shaft B402 and the roller B406 rotate around a longitudinal axis B408.

[0116] In the mechanical device B400, the rotation drive unit B404 includes a motor B410 and a gearbox B412. The motor B410 can be any type of motor suitable for driving the head shaft B402 through the gearbox B412. For example, in some embodiments, the motor B410 can be an electric motor. In other embodiments, the motor B410 can be a hydraulic motor. Figure B10 As shown, the motor B410 is located outside the drum B406. In addition, the motor B410 is offset from the longitudinal axis B408 (i.e., the motor is not coaxial with the longitudinal axis B408). The offset position of the motor B410 facilitates access to the motor B410 (e.g., for replacement or maintenance operations) and also helps to improve the cooling of the motor B410 (because the motor B410 is located outside the drum B406 and is a certain distance away from the material cut by the drum B406).

[0117] In the mechanical device B400, the head shaft B402 is mounted on the main frame B414 through the bearing B416, which allows the head shaft B402 and the roller B406 to rotate relative to the main frame B414. The torque arm B418 fixes the gearbox B412 in place and prevents the gearbox B412 from rotating in the opposite direction relative to the main frame B414.

[0118] Figure B10The embodiment includes a single motor B410. However, according to the present disclosure, in other embodiments, the mechanical device may include multiple motors. In addition, the motors may be located on the same side of the drum or on opposite sides of the drum.

[0119] For example, Figure B11 is a perspective view of an open-pit mining machine B500 that includes another mechanical device B502. The mechanical device B502 includes a gearbox B506 that is configured to be used with one or more motors B504. Specifically, the mechanical device B502 includes two motors B504. By using multiple motors B504 instead of a single motor, for a given total power, each motor B504 can provide a portion of the total power instead of requiring a single motor to provide the total power. In addition, the use of multiple motors B504 can provide redundancy (for example, when one motor B504 fails, another motor B504 can continue to drive the drum B508 to rotate through the gearbox B506). Compared with the mechanical device B400 (such as Figure B11 As shown in FIG. 1 , in this embodiment, both motors B504 are offset from the longitudinal axis B510 of the drum B508. In addition, in this embodiment, the mechanical device B502 constitutes at least a portion of a boom that can be selectively raised and lowered relative to the rest of the open-pit mining machine B500.

[0120] Figure B12 yes Figure B11 A side view of the surface miner B500 is shown. Figure B13 yes Figure B11 A top view of the surface miner B500 is shown. Figure B14 This is a front perspective view of the mechanical device B502. Figure B15 is a rear perspective view of the mechanism B502.

[0121] Although not shown, in some embodiments, the surface miner's mechanical arrangement may include two gearboxes located on opposite sides of the drum. Each gearbox may be driven by one or more motors. For example, the surface miner may be configured with Figure B9 (Chain Trencher) A similar mechanical device.

[0122] Furthermore, in the excavators described herein, it is desirable to isolate the motor from the associated gearbox to protect the motor from vibrations and / or oscillations generated or experienced by the gearbox and / or cutting tool.

[0123] For example, Figure B16 is a simplified schematic diagram of another mechanical device B600 for open-pit mining machines. Mechanical device B600 is similar to mechanical device B400 (such as Figure B10) is somewhat similar. However, in this mechanical device B600, the motor B602 is not directly connected to the transmission B604. Instead, the motor B602 is connected to the transmission B604 through an elastic coupling B606 (such as a universal shaft). The use of the elastic coupling B606 allows the motor B602 to move relative to the transmission 604. Therefore, the vibration and / or swing experienced by the transmission B604 will not be transmitted to the motor B602. In addition, the motor B602 can be mounted on one or more isolators (not shown) to further suppress any vibration and / or swing.

[0124] As another example, Figure B17 A simplified schematic diagram of another mechanical device B700 of a chain opener is shown. The mechanical device B700 is similar to the mechanical device B200 (such as Figure B7 ) is somewhat similar. However, in this mechanical device B700, the motor B702 is not directly connected to the transmission B704. Instead, the motor B702 is connected to the transmission B704 through an elastic coupling B706 (such as a universal shaft). The use of the elastic coupling B706 allows the motor B702 to move relative to the transmission B704. Therefore, the vibration and / or swing experienced by the transmission B704 will not be transmitted to the motor B702. In this embodiment, the motor B702 is mounted on the main frame B708 ​​of the chain trencher and can be mounted through one or more isolators (not shown) to further suppress any vibration and / or swing.

[0125] Isolation system Figure C1 is a perspective view of an example surface miner C100 that includes at least some of the embodiments described herein. In addition, the systems and methods described herein may also be used with other excavators (eg, chain trenchers).

[0126] The mechanical device C102 of the surface miner C100 includes two motors C104 and a gearbox C106. The motors C104 drive a drum C108 of the surface miner C100 to rotate so as to dig or cut materials (such as soil).

[0127] Figure C2 yes Figure C1 A side view of the surface miner C100 is shown. Figure C3 yes Figure C1 A top view of the surface miner C100 is shown. Figure C4 is along Figure C3 A cross-sectional view of the surface mining machine C100 taken along line C4-C4 is shown.

[0128] Figure C5 It can be used with open-pit miner C100 (such as Figure C1 A simplified schematic diagram of an engine generator bracket C200 for use with an engine generator bracket C200 is shown. Figure C6 It is a perspective view of the engine generator bracket C200. Figure C7 Another simplified schematic diagram of the engine generator bracket C200.

[0129] The engine generator bracket C200 includes a generator C202 and an engine C204 mounted on a frame C206 of an excavator (such as an open-pit miner or a chain trencher). In order to reduce the vibration and / or swing that the generator C202 may experience, the generator C202 is mounted to the frame C206 through one or more first isolators C208. In this embodiment, at least some of the first isolators C208 are generally at a 45° angle to the longitudinal axis C210 of the generator C202. Alternatively, the first isolator 208 can have any suitable configuration. In addition, the engine C204 can also be mounted on the frame C206 through one or more second isolators C212. In addition, in this embodiment, the generator C202 is connected to the engine C204 through an elastic coupling C214 (such as a universal shaft). The use of the elastic coupling C214 allows the generator C202 to move relative to the engine C204 (for example, when subjected to forces generated by vibration and / or swing).

[0130] The systems and methods described herein include a mechanical device for electrically driving a chain trencher, the mechanical device including a generator driven by a diesel engine, an electric motor (e.g., a permanent magnet asynchronous motor connected to or mounted on a gearbox mounted on a trencher head shaft with a torque arm for holding the gearbox from rotating about the axis of the head shaft), and a control system that controls the power (e.g., current and voltage) generated by the generator to control the operating characteristics of the motor.

[0131] The systems and methods described herein also include a control system for an excavator having a cutter drive system including a "torque converter" as a drive system, the torque converter having no direct mechanical connection between the input and output and allowing slip between the input and output, during which the torque at the output can increase. The control system automatically controls the speed of the ground drive system and automatically controls the slip characteristics of the torque converter based on feedback signals (including engine power calculated by the electronic control unit). The "torque converter" may include an electromechanical transmission device. In addition, the "torque converter" may also be a hydraulic torque converter.

[0132] The systems and methods described herein also include flexible configurations of the trencher to provide either electric or hydraulic drive.

[0133] The present disclosure provides an excavator with an electric motor and a control system. The control system includes an algorithm that controls the applied power by automatically controlling speed and torque to maintain a constant maximum power. This allows the excavator to slow down by more than 30% to apply more and more force to the excavated material as the required force increases, while maintaining a constant power consumption. This is unique to electric mechanical equipment and is not possible with mechanical systems (such as hydrostatics or torque converters).

[0134] In a hydrostatic system, torque increases as speed increases, but only to a certain point. A typical engine operating curve has maximum power at approximately 2,000 to 2,400 rpm and maximum torque at approximately 1,600 to 1,800 rpm. Therefore, once the engine speed drops below 2,000 rpm, the power produced by the engine drops. With a torque converter system, as torque increases, slip also increases. The power transmitted to the excavator drops because the increase in torque is achieved through the inherent inefficiency of the torque converter. Using the electromechanical drive described in this article has advantages over the above two options.

[0135] The present disclosure provides an excavator. The excavator includes an excavating device on which a cutting tool is mounted (for example, the cutting teeth of a trencher are mounted on a trencher chain, the trencher chain is mounted on a trencher boom, and the chain passes around a drive sprocket and an end sprocket; the cutting teeth of a terrain leveler are mounted on a drum, etc.). The excavator also includes an excavating device drive system, which provides power to the excavating device to move the cutting tool on a cutting machine travel path (for example, for a trencher, the excavating device drive system is a head shaft, on which a pair of drive sprockets are mounted, and the sprockets are engaged with the trencher chain to drive the chain to rotate around the trencher boom. For another example, the motor of a direct-drive terrain leveler is directly connected to the drum, or a pair of drums of a chain-driven terrain leveler are mounted together with the end idler of the trencher boom - note: this travel path is different from the movement caused by a separate drive device moving the entire boom or moving the entire machine). The excavation device drive system includes an electric motor and a motor controller, wherein the control system includes a control algorithm configured to control the speed of the excavation device drive system to a predetermined first excavation speed when the power extracted for the system is lower than a predetermined target power; or when the force required to push the cutting tool exceeds the force that the excavation device drive system can generate when operating at the first excavation speed under the predetermined target power, automatically reduce the speed of the motor and increase the torque generated by the motor to maintain the predetermined target power.

[0136] In one embodiment, the excavator also includes an internal combustion engine that powers a generator, wherein the generator powers an electric motor of the excavating equipment drive system, and the control system is configured to manage the power consumption generated by the generator so that the engine operates at an optimal operating state (for example, allowing the engine to operate between 1900 and 2100 rpm), while the speed and torque generated by the electric motor of the excavating equipment drive system are independently varied to provide the force required to propel the cutting tool.

[0137] In one embodiment, the control system automatically adjusts the target power applied to the excavation equipment drive system based on the engine power data stream generated by the engine controller.

[0138] In one embodiment, the excavator also includes a propulsion system for moving the excavating device, wherein the control system further includes an algorithm for automatically controlling the propulsion system: i) as a function of the speed of the excavating system (for example, if the excavating speed is less than a predetermined percentage of a predetermined first excavating speed, the propulsion system will slow down or reduce the force pushing the cutting system); or ii) as a function of the torque generated by the electric motor (for example, if the torque exceeds a predetermined percentage of the maximum torque required to produce a predetermined target power at a predetermined first excavating speed, the propulsion system will slow down or reduce the force pushing the cutting system).

[0139] In one embodiment, the propulsion system slows down or reduces the force pushing the cutting system only when i) the excavation system speed is equal to or less than 0.7 times the predetermined first excavation speed; or ii) the torque generated by the electric motor is equal to or greater than 1.4 times the motor.

[0140] In the present disclosure, there is provided an excavator including a diesel engine, a cutting system drive, and an associated control system. The excavator includes a propulsion system and a power transmission device, which may include at least one of the following: i) a torque converter that transmits power from the engine to the active cutting system drive device, the torque converter being a system without a direct mechanical link, allowing slip between an input end connected to the engine and an output end connected to the active cutting system, wherein torque increases with increasing slip, having a variable slip characteristic, a variable torque and speed characteristic; and ii) an electromechanical transmission device including a generator, a motor, and a power electronic device, wherein the power electronic device can control the variable torque and speed characteristics. The control system uses the engine load calculated by the engine as a control parameter to control the torque and speed characteristics of the power transmission device, and uses the output speed of the power transmission device to control the propulsion system.

[0141] The present disclosure provides an excavator. The excavator includes a diesel engine and an active cutting system, the diesel engine having an engine control unit (ECU), the unit controlling and monitoring a fuel system and an intake system to provide diesel and combustion air to the engine, the ECM calculating an engine load parameter at least partially based on the fuel and air flow rates. The excavator also includes a power transmission device that transmits power from the diesel engine to the active cutting system at a variable operating speed, the variable operating speed having operating parameters that affect the variable torque and speed characteristics of the power transmission device (for example, a system without direct mechanical connection, allowing slip between an input end connected to the engine and an output end connected to the active cutting system, wherein the torque increases with increasing slip). The excavator also includes a propulsion system that propels the active cutting system during excavation, and a control system that controls the propulsion system according to the operating speed of the power transmission device and a control system that controls the operating parameters of the power transmission device according to the engine load parameters. The propulsion system can be controlled at a first frequency, such as on the order of one thousandth of a second, and the operating parameters can be controlled at a second frequency, such as on the order of one ten-thousandth of a second.

[0142] In one embodiment, the power transmission device is an electromechanical transmission device having a generator physically coupled to the engine, an electric motor physically coupled to the active cutting system, and a power electronic device electrically coupling the generator to the electric motor. In addition, the control system can also control a target power defined as an operating parameter of the power electronic device, increase the target power when the engine load parameter is below a predetermined target, and decrease the target power when the engine load parameter is above the predetermined target.

[0143] In one embodiment, the power transmission is a torque converter transmission with adjustable operating parameters. In addition, the control system can control one of the spacing of the stator and the bypass clutch to increase or decrease the load on the engine.

[0144] The embodiments described herein relate to the use of one or more electronic or computing devices. These devices typically include a processor, a processing device or a controller, such as a general-purpose central processing unit (CPU), a graphics processing unit (GPU), a microcontroller, a reduced instruction set computer (RISC) processor, an application-specific integrated circuit (ASIC), a programmable logic circuit (PLC), a field programmable gate array (FPGA), a digital signal processing (DSP) device and / or any other circuit or processing device capable of performing the functions described herein. The methods described herein may be encoded as executable instructions, embodied in a computer-readable medium, including but not limited to storage devices and / or memory devices. These instructions, when executed by a processing device, cause the processing device to perform at least a portion of the methods described herein. The above examples are not intended to limit the definition and / or meaning of the terms processor and processing device in any way.

[0145] As used herein, the terms "about," "substantially," "substantially," and "approximately," when used in conjunction with ranges of size, concentration, temperature, or other physical or chemical properties or characteristics, are intended to encompass variations that may exist in the upper and / or lower limits of the range of the property or characteristic, including variations due to, for example, rounding, measurement method, or other statistical variations.

[0146] When introducing elements of the present disclosure or embodiments thereof, the articles "a," "an," "the," and "said" mean that there are one or more of the elements. The terms "comprises," "comprising," "containing," and "having" are intended to be inclusive, meaning that there may be additional elements in addition to the listed elements. The use of terms indicating specific directions (e.g., "top," "bottom," "side," etc.) is for convenience of description and does not require any specific orientation of the items being described.

[0147] As various changes could be made in the above constructions and methods without departing from the scope of the present disclosure, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

1. An excavator, comprising: an excavation device having a plurality of cutting tools mounted thereon; as well as an excavator drive system that provides power to the excavator to move at least one of the plurality of cutting tools through a cutter travel path, wherein the excavator drive system includes an electric motor and a motor controller, the electric motor being powered by a power source, wherein the motor controller is programmed to control the speed of the excavation device drive system via a control algorithm, wherein the control algorithm, when executed by the motor controller, causes the motor controller to set the speed of the excavation device drive system to a predetermined excavation speed based on a predetermined target power, the predetermined target power being associated with a target torque generated by the electric motor, and wherein, when the power transmitted to the electric motor is lower than the predetermined target power, the speed of the excavation device drive system is set to a predetermined first excavation speed, and wherein, the speed of the excavation device drive system is set to a predetermined second excavation speed to keep the power transmitted to the electric motor at the predetermined target power, the predetermined second excavation speed being less than the predetermined first excavation speed and being associated with an increase in the target torque generated by the electric motor, and the speed of the excavation device drive system is set to the predetermined second excavation speed when a first force required to push at least one of the plurality of cutting tools exceeds a second force generated by the excavation device drive system when operating at the predetermined first excavation speed at the predetermined target power.

2. The excavator of claim 1, wherein the power source comprises at least one of an energy storage device, an energized power line, and an engine.

3. An excavator according to claim 1, wherein the power source includes an internal combustion engine that powers a generator, wherein the generator provides power to the electric motor that powers the excavator drive system, and the motor controller is configured to manage the power transmitted to the electric motor so that the internal combustion engine operates in an optimal operating state, the optimal operating state including the change values ​​of speed and torque generated by the electric motor that powers the excavator drive system, wherein the change values ​​of speed and target torque vary independently to provide the first force required to propel at least one of the plurality of cutting tools.

4. The excavator according to claim 3, wherein: The motor controller automatically adjusts the predetermined target power applied to the excavating device drive system based on an engine power data stream generated by an engine controller.

5. The excavator according to claim 1, further comprising a propulsion system for moving the excavating device, wherein: The motor controller is further programmed to automatically control the propulsion system via a second control algorithm, wherein the second control algorithm, when executed by the motor controller, causes the motor controller to control the propulsion system based on at least one of a speed and a torque generated by the electric motor.

6. The excavator according to claim 5, wherein: When the speed is equal to or less than 0.7 times the predetermined first digging speed, and / or the torque is equal to 1.4 times the target torque, the motor controller will reduce the speed of the propulsion system or reduce the first force pushing at least one of the multiple cutting tools.

7. An excavator, comprising: A diesel engine having an engine control unit (ECU) that controls and monitors a fuel system and an air intake system that provide diesel and combustion air to the diesel engine, wherein the ECU calculates an engine load parameter based at least in part on the amount of fuel and the amount of air flow; Active cutting system; a power transmission device for transmitting power from the diesel engine to the active cutting system at a variable operating speed, wherein the variable operating speed is based on operating parameters affecting variable torque and speed characteristics of the power transmission device; as well as a propulsion system to propel the active cutting system during excavation; as well as A control system controls the propulsion system based on a variable operating speed of the power transmission, wherein the control system controls the operating parameter of the power transmission based on the engine load parameter.

8. The excavator according to claim 7, wherein: The power transmission is an electromechanical transmission having a generator physically coupled to the diesel engine, an electric machine physically coupled to the active cutting system, and power electronics electrically coupling the generator to the electric machine.

9. The excavator according to claim 8, wherein: The control system controls the target power of the power electronic device according to a predetermined target of the engine load parameter, the target power increasing when the engine load parameter is lower than the predetermined target, and the target power decreasing when the engine load parameter is higher than the predetermined target.

10. The excavator according to claim 7, wherein: The power transmission is a torque converter transmission with adjustable operating parameters.

11. The excavator of claim 10, wherein the control system controls at least one of a stator pitch and a bypass clutch as the operating parameter of the power transmission device.

12. A mechanical device for an excavator, the mechanical device comprising: Cutting tools; a head shaft coupled to the cutting tool, the head shaft defining a longitudinal axis; a gearbox coupled to the head shaft so that the head shaft supports the gearbox; as well as A motor is coupled to the gearbox, wherein the motor is offset from a longitudinal axis of the head shaft, and wherein the motor is configured to drive rotation of the head shaft and the cutting tool through the gearbox.

13. The mechanical device of claim 12, wherein the motor is an electric motor.

14. The machine of claim 12, wherein the motor is a hydraulic motor.

15. The machine of claim 12, wherein the cutting tool is a chain of a chain trencher.

16. The machine of claim 12, wherein the cutting tool is a drum of a surface miner.

17. The mechanical device of claim 12, wherein the motor is connected to the gearbox via an elastic coupling.

18. The machine of claim 12, wherein the motor is mounted to a frame of the excavator via at least one isolator.

19. A mechanical device for an excavator, the mechanical device comprising: Cutting tools; a head shaft of the cutting tool; and at least one gearbox coupled to the head shaft such that the head shaft supports the gearbox; as well as A plurality of motors, wherein the plurality of motors are configured to drive the head shaft and the cutting tool to rotate, and wherein at least one of the plurality of motors is coupled to at least one gearbox.

20. The machine of claim 19, wherein the at least one gearbox comprises a single gearbox, the plurality of motors comprises a first motor and a second motor, each of the first motor and the second motor being coupled to the single gearbox.

21. The mechanical device of claim 19, wherein the at least one gearbox comprises a first gearbox and a second gearbox, the first gearbox and the second gearbox are located on opposite sides of the cutting tool, and the plurality of motors comprises a first motor coupled to the first gearbox and a second motor coupled to the second gearbox.

22. The machine of claim 19, wherein at least one of the plurality of motors is an electric motor.

23. The machine of claim 19, wherein at least one of the plurality of motors is a hydraulic motor.

24. The machine of claim 19, wherein the cutting tool is a chain of a chain trencher.

25. The machine of claim 19, wherein the cutting tool is a drum of a surface miner.

26. The machine of claim 19, wherein at least one of the plurality of motors is coupled to the at least one gearbox via a flexible coupling.

27. The machine of claim 19, wherein at least one of the plurality of motors is mounted to a frame of the excavator via at least one isolator.

28. The mechanical device of claim 19, wherein at least one of the plurality of motors is offset from a longitudinal axis of the head shaft.

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