Patent Application
20150101322
The present invention relates to system architecture for mobile hydraulic equipment, and more particularly to system architecture for mobile hydraulic equipment that utilizes electro hydrostatic actuators (EHAs).
The current state of the art for mobile hydraulic equipment involves a prime mover (usually an internal combustion engine, but sometimes an electric motor) coupled to a hydraulic pump, which takes hydraulic fluid from a reservoir and distributes pressurized hydraulic fluid to all of the cylinders, valves, and motors in the system. The fluid is then routed through a heat exchanger and delivered back to the reservoir. There is a desire for improved equipment that is simpler mechanically, more robust, more energy efficient, and that has lower emissions.
In accordance with a first aspect of the present invention there is provided a system architecture for use on mobile hydraulic equipment. The system architecture includes a power system that includes an electrical generator, power supply electronics in electrical communication with the electrical generator, an electrical storage medium in electrical communication with the electrical generator and in parallel with the power supply electronics, and an electrical power bus for distributing power from the power system to a first component control system. The first component control system includes first drive electronics and at least a first electro hydrostatic actuator. The system architecture also includes a main controller. The power system is in data communication and electrical communication with the main controller, and the first component control system is in data communication with the main controller.
In a preferred embodiment, the first drive electronics include at least a first microcontroller in electrical communication with the first electro hydrostatic actuator and in data communication with the main controller. Preferably, the first drive electronics include at least a first motor driver. In a preferred embodiment, the first electro hydrostatic actuator is a linear electro hydrostatic actuator. In another preferred embodiment, the first electro hydrostatic actuator is a rotary electro hydrostatic actuator. In a preferred embodiment, the first component control system includes a second electro hydrostatic actuator in electrical communication with the first microcontroller.
In a preferred embodiment, the system architecture includes a second component control system that includes second drive electronics and at least a second electro hydrostatic actuator. The second component control system is in data communication with the main controller. Preferably, the first drive electronics include at least a first microcontroller in electrical communication with the first electro hydrostatic actuator and in data communication with the main controller, and the second drive electronics include at least a second microcontroller in electrical communication with the second electro hydrostatic actuator and in data communication with the main controller. In this embodiment, the first electro hydrostatic actuator is a linear electro hydrostatic actuator and the second electro hydrostatic actuator is a rotary electro hydrostatic actuator.
In accordance with another aspect of the present invention there is provided a method for controlling a mobile hydraulic machine. The method includes the steps of generating a control signal by interacting with an operator interface, transmitting the control signal to a main controller, interpreting and translating the control signal and transmitting it to drive electronics that include a microcontroller and a motor driver, and actuating an electro hydrostatic actuator in response to the control signal. In a preferred embodiment, the mobile hydraulic machine includes a power system that comprises an electrical generator, power supply electronics in electrical communication with the electrical generator, an electrical storage medium in electrical communication with the electrical generator and in parallel with the power supply electronics, and an electrical power bus for distributing power from the power system to a first component control system. The drive electronics and electro hydrostatic actuator are part of the first component control system.
In accordance with an aspect of the present invention there is provided a system architecture for mobile hydraulic equipment. In a preferred embodiment, the present invention removes the hydraulic hoses, tubing and heat exchangers on traditional mobile hydraulic equipment, such as, for example, an excavator, and replaces the components with local hydraulic circuits. For example, the linear EHAs can replace all linear hydraulic actuators and cylinders, and the rotary EHAs, such as hydrostatic drives driven by electric motors instead of gasoline engines, can replace all rotary hydraulic motors. This provides an all electric vehicle architecture which allows for actuator forces normally found on traditional hydraulic systems.
The size of the system architecture can be scaled depending on the type of equipment on which it is implemented. For example, the bore of the EHA is sized for the appropriate force and the mounting pins are sized to handle the force of the actuator. The size of the battery bank and electrical generator are also taken into consideration.
By using rotary EHAs and linear EHAs in place of traditional hydraulic cylinders and motors, the system used in the mobile hydraulic equipment has no more need for bulky and heavy hydraulic hose, tube, and fittings in the system, as well as the central hydraulic fluid reservoir, pump, heat exchanger, accumulator, and other miscellaneous valves and fittings. A prime mover no longer must be oversized to be able to spin the large central hydraulic pump to supply the demands of the system. Instead, in a preferred embodiment of the present invention, a smaller prime mover can be coupled to the electrical generator which in turn charges the battery bank or capacitors. The battery bank can supply electrical power to the linear EHAs and rotary EHAs during times of peak power consumption, while the electrical generator runs at its best efficiency point charging the batteries during periods of low load in the machine cycle. In this way, a smaller electrical that has fewer emissions and is more fuel efficient can be used, without sacrificing machine performance. The overall system, if properly designed and installed, should have less mass, fewer emissions, higher reliability, and similar performance to a traditional hydraulic system.
The system architecture described above and shown in the figures can be used on mobile equipment such as bulldozers, excavators, telehandlers (basically a rough terrain forklift), front end loaders (wheel loaders), backhoes, harvesters (both timber and agricultural), and the like. There are many variations of these types of machines, and there are many more machines in which the system architecture can be implemented. By integrating the linear EHAs, rotary EHAs, and other electronic powertrain components, a smaller, cleaner electrical generator can be used while still maintaining the performance of the machine when compared to the prior art.
In another embodiment, a hybrid approach is contemplated wherein some of the hydraulic components are replaced with the system architecture that includes linear EHAs or rotary EHAs and other components are not replaced. For example, the components that work the bucket and articulate the center of the vehicle on a front end loader can be replaced with linear EHAs and it can include conventional hydraulic motor(s) to drive the wheels.
In accordance with another aspect of the present invention, there is provided a method for powering a mobile hydraulic machine. The method includes the steps of providing the machine with an electrical generator to generate power, transmitting the power from the generator to power electronics and an electrical storage medium, transmitting the power from the power electronics or the electrical storage medium to an electrical storage bus, and transmitting the power from the electrical storage bus to an electro hydrostatic actuator that is operationally connected to a component on the machine. In a preferred embodiment, the step of transmitting the power from the electrical storage bus to an electro hydrostatic actuator includes transmitting the power from the electrical storage bus to a microcontroller, transmitting the power from the microcontroller to a motor driver, and transmitting the power from the motor driver to the electro hydrostatic actuator.
In accordance with another aspect of the present invention, there is provided a method for controlling a mobile hydraulic machine. The method includes the steps of generating a control signal by interacting with an operator interface, transmitting the control signal to a main controller, interpreting and translating the control signal and transmitting it to a microcontroller, interpreting and translating the control signal and transmitting it to a motor driver, and actuating an electro hydrostatic actuator using the motor driver in response to the control signal. In a preferred embodiment, the electro hydrostatic actuator has a position transducer associated therewith, and the method includes closed loop feedback between the microcontroller and the position transducer. It will be appreciated that in a preferred embodiment, each component is controlled independently of the other components via the components own microcontroller. However, it will be further appreciated that each microcontroller may control only a single EHA or multiple EHAs.
The invention may be more readily understood by referring to the accompanying drawings in which:
Like numerals refer to like parts throughout the several views of the drawings.
The following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. References to one or another embodiment in the present disclosure can be, but not necessarily are, references to the same embodiment; and, such references mean at least one of the embodiments.
Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. Appearances of the phrase “in one embodiment” in various places in the specification do not necessarily refer to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments.
The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Certain terms that are used to describe the disclosure are discussed below, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the disclosure. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks: The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that the same thing can be said in more than one way.
Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein. Nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and is not intended to further limit the scope and meaning of the disclosure or of any exemplified term. Likewise, the disclosure is not limited to various embodiments given in this specification.
Without intent to further limit the scope of the disclosure, examples of instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions, will control.
It will be appreciated that terms such as “front,” “back,” “top,” “bottom,” “side,” “short,” “long,” “up,” “down,” and “below” used herein are merely for ease of description and refer to the orientation of the components as shown in the figures. It should be understood that any orientation of the components described herein is within the scope of the present invention.
Referring now to the drawings, wherein the showings are for purposes of illustrating the present invention and not for purposes of limiting the same,
The present invention includes a system level architecture 10 for mobile hydraulic machinery that will preferably reduce the weight of the machinery, increase fuel efficiency, and make machine servicing easier for operators in the field when compared to the prior art. The system utilizes at least one electro hydrostatic actuator (EHA) 12. The EHA 12 is essentially a miniature self-contained hydraulic system. As shown in
As shown in
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The machine on which the system architecture 10 is implemented includes an operator interface 30, which preferably mimics the interface of a conventional machine. For example, the operator interface may include control sticks which the user may use to maneuver the boom of an excavator utilizing the system architecture described herein. The operator interface 30 communicates with a main controller 32 via a communication bus 34. In a preferred embodiment, the main controller 32 is a computer. In a preferred embodiment, the communication bus 34 can be a cable through which a signal can be sent. However, it will be appreciated by those of ordinary skill in the art that this communication bus 34 can be any means by which a signal can be sent, including but not limited to Wi-fi, Bluetooth, fiber optics, infrared, Zigbee, etc. However, it will be appreciated by those of ordinary skill in the art that the main controller 32 can be any apparatus that can interpret signals from the operator interface 30 and transmit signals to other components in the system.
In a preferred embodiment, the main controller 32 is operationally connected to the electrical power bus 22 and the drive electronics 24 via the communication bus 34. Preferably, the main controller 32 can monitor power usage and coordinate the transfer of power in accordance with the power requirements of the electrical power bus 22 and the drive electronics 24. Further, as discussed above, in a preferred embodiment, the drive electronics 24 comprise at least one motor driver 26 and at least one microcontroller 28. One of ordinary skill in the art will appreciate that the drive electronics 24 can comprise any number of motor drivers 26 and microcontrollers 28. In a preferred embodiment, the drive electronics 24 are operationally connected to the EHA 12 via the communication bus 34. However, it will be appreciated by those of ordinary skill in the art that the drive electronics can be operationally connected to any number of EHAs 12. Thus, when a user interacts with the operator interface 30 of this preferred embodiment, the operator interface 30 sends a signal to the main controller 32. The main controller 32 then interprets the signal from the operator interface 30 and transmits control signals to operationally connected component control systems. For example, if a user of an earth-moving machine encompassing the system architecture 10 desires to activate a component of the machine that utilizes an EHA 12, then the user will interact with the operator interface 30. The signal from the operator interface 30 will indicate that an EHA 12 should be actuated. The main controller 30 then transmits a signal to the electrical power bus 22, alerting the electrical power bus 22 of power requirements, and also transmits a signal to the drive electronics 24 that are operationally connected to the EHA 12 in the component. The drive electronics 24 then receive and interpret this signal from the main controller 32 and actuate the correct EHA 12 accordingly.
Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling of connection between the elements can be physical, logical, or a combination thereof. Additionally, the words “herein,” “above,” “below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above Detailed Description of the Preferred Embodiments using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.
The above-detailed description of embodiments of the disclosure is not intended to be exhaustive or to limit the teachings to the precise form disclosed above. While specific embodiments of and examples for the disclosure are described above for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. For example, while processes or blocks are presented in a given order, alternative embodiments may perform routines having steps, or employ systems having blocks, in a different order, and some processes or blocks may be deleted, moved, added, subdivided, combined, and/or modified to provide alternative or subcombinations. Each of these processes or blocks may be implemented in a variety of different ways. Also, while processes or blocks are at times shown as being performed in series, these processes or blocks may instead be performed in parallel, or may be performed, at different times. Further any specific numbers noted herein are only examples: alternative implementations may employ differing values or ranges.
The above-detailed description of embodiments of the disclosure is not intended to be exhaustive or to limit the teachings to the precise form disclosed above. While specific embodiments of and examples for the disclosure are described above for illustrative purposes, various equivalent modifications are possible within the scope of the disclosure, as those skilled in the relevant art will recognize. Further, any specific numbers noted herein are only examples: alternative implementations may employ differing values, measurements or ranges. It will be appreciated that any dimensions given herein are only exemplary and that none of the dimensions or descriptions are limiting on the present invention.
The teachings of the disclosure provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments.
Any patents and applications and other references noted above, including any that may be listed in accompanying filing papers, are incorporated herein by reference in their entirety. Aspects of the disclosure can be modified, if necessary, to employ the systems, functions, and concepts of the various references described above to provide yet further embodiments of the disclosure.
These and other changes can be made to the disclosure in light of the above Detailed Description of the Preferred Embodiments. While the above description describes certain embodiments of the disclosure, and describes the best mode contemplated, no matter how detailed the above appears in text, the teachings can be practiced in many ways. Details of the system may vary considerably in its implementation details, while still being encompassed by the subject matter disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the disclosure should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features or aspects of the disclosure with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the disclosures to the specific embodiments disclosed in the specification unless the above Detailed Description of the Preferred Embodiments section explicitly defines such terms. Accordingly, the actual scope of the disclosure encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the disclosure under the claims.
While certain aspects of the disclosure are presented below in certain claim forms, the inventors contemplate the various aspects of the disclosure in any number of claim forms. For example, while only one aspect of the disclosure is recited as a means-plus-function claim under 35 U.S.C. §112, ¶6, other aspects may likewise be embodied as a means-plus-function claim, or in other forms, such as being embodied in a computer-readable medium. (Any claims intended to be treated under 35 U.S.C. §112, ¶6 will begin with the words “means for”). Accordingly, the applicant reserves the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the disclosure.
Accordingly, although exemplary embodiments of the invention have been shown and described, it is to be understood that all the terms used herein are descriptive rather than limiting, and that many changes, modifications, and substitutions may be made by one having ordinary skill in the art without departing from the spirit and scope of the invention.
This application claims the benefit of U.S. Provisional Application No. 61/890,508, filed Oct. 14, 2013, and U.S. Provisional Application No. 61/900,242, filed Nov. 5, 2013, which are both herein incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 61890508 | Oct 2013 | US | |
| 61900242 | Nov 2013 | US |
