CN115111210A - Motor pump, hydraulic system and mechanical equipment - Google Patents

Motor pump, hydraulic system and mechanical equipment Download PDF

Info

Publication number
CN115111210A
CN115111210A CN202110294437.0A CN202110294437A CN115111210A CN 115111210 A CN115111210 A CN 115111210A CN 202110294437 A CN202110294437 A CN 202110294437A CN 115111210 A CN115111210 A CN 115111210A
Authority
CN
China
Prior art keywords
motor
pump
variable
speed
displacement
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110294437.0A
Other languages
Chinese (zh)
Inventor
刘子凡
王墨林
K·贝尼尔施克
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bosch Rexroth Beijing Hydraulic Co Ltd
Original Assignee
Bosch Rexroth Beijing Hydraulic Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bosch Rexroth Beijing Hydraulic Co Ltd filed Critical Bosch Rexroth Beijing Hydraulic Co Ltd
Priority to CN202110294437.0A priority Critical patent/CN115111210A/en
Priority to PCT/CN2022/079894 priority patent/WO2022193998A1/en
Publication of CN115111210A publication Critical patent/CN115111210A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/20—Drives; Control devices
    • E02F9/22—Hydraulic or pneumatic drives
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/06—Control using electricity
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
    • F15B21/08—Servomotor systems incorporating electrically operated control means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
    • H02P6/08—Arrangements for controlling the speed or torque of a single motor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity

Abstract

An electric motor pump comprising: a variable speed motor (1) having a motor controller (2) and a motor shaft (3); at least one variable displacement pump (4, 5) driven by the motor shaft; and a control unit (8) configured to: acquiring the current working state of a motor pump, wherein the current working state at least comprises the current rotating speed of a variable speed motor, the current displacement and the output pressure of a variable pump; acquiring an updated flow demand; executing optimization operation based on the updated flow demand and the current working state of the motor pump, wherein the optimization operation takes the total efficiency and/or the response time of the motor pump as optimization targets and takes the motor speed and the variable pump displacement as optimization variables to obtain the optimized motor speed and the optimized variable pump displacement; and controlling the rotation speed of the variable speed motor to become the optimized motor rotation speed, and controlling the displacement of the variable displacement pump to become the optimized displacement of the variable displacement pump.

Description

Motor pump, hydraulic system and mechanical equipment
Technical Field
The present application relates to a motor pump for a hydraulic system comprising a combination of a variable speed motor and a variable displacement pump. The application also relates to a hydraulic system employing such a motor pump, in particular in an off-highway vehicle, such as an excavator.
Background
In hydraulic systems for off-highway vehicles, such as excavators, there is a trend to use electric motor pumps to provide hydraulic power to actuators in lieu of the traditional diesel engine power source. At present, a motor pump of a hydraulic system of an off-highway vehicle usually adopts a combination of a motor with a fixed rotating speed (i.e. a scheme of simulating a diesel engine, which works at a certain rotating speed) and a variable pump, or a combination of a variable speed motor and a fixed displacement pump. This often results in high energy consumption and thus increased cell design cost. Also, the operation control of the motor pump is generally a scheme simulating a diesel-driven hydraulic pump, which causes limitations in the performance of the hydraulic system. Furthermore, the response time of prior art motor pumps is sometimes not ideal.
Accordingly, improvements in the configuration and control scheme of electric motor pumps used in hydraulic systems for off-highway vehicles are desirable.
Disclosure of Invention
It is an object of the present application to provide an improved motor pump for use in a hydraulic system that is capable of providing an optimized performance index while reducing energy consumption and dynamic response time.
To this end, the present application provides, in one aspect thereof, a motor pump comprising:
a variable speed motor having a motor controller and a motor shaft;
at least one variable displacement pump driven by a motor shaft; and
a control unit configured to:
acquiring the current working state of a motor pump, wherein the current working state at least comprises the current rotating speed of a variable speed motor, the current displacement and the output pressure of a variable pump;
obtaining an updated flow demand for the motor pump;
executing optimization operation based on the updated flow demand and the current working state of the motor pump, wherein the optimization operation takes the total efficiency and/or the response time of the motor pump as optimization targets and takes the motor speed and the variable pump displacement as optimization variables to obtain the optimized motor speed and the optimized variable pump displacement; and
controlling the speed of the variable speed motor to an optimized motor speed and controlling the displacement of the variable displacement pump to an optimized displacement of the variable displacement pump.
In one embodiment, the optimization objectives are motor pump total efficiency and motor pump response time, which are assigned respective weight values that can be varied for specific operational requirements.
In one embodiment, the control unit is provided with at least the following control modes:
a standard mode, in which two weight values are preset according to the intended use of the motor pump;
an efficiency priority mode, wherein the weighted value of the total efficiency of the motor pump is greater than the weighted value of the response time of the motor pump;
a dynamic mode wherein a weighted value of motor pump response speed is greater than a weighted value of motor pump total efficiency.
In one embodiment, the control unit is further provided with a temperature control mode, wherein the control unit controls the motor pump to operate at the optimized motor speed and variable pump displacement within a preset motor temperature range and/or an ambient temperature range, and when the motor temperature range and/or the ambient temperature range are exceeded, the control unit keeps the variable speed motor operating at a speed lower than a set speed limit.
In one embodiment, a noise control mode is also provided in the control unit, wherein the control unit determines a maximum rotational speed based on the maximum allowable motor pump noise and keeps the variable speed motor running at a rotational speed below the maximum rotational speed.
In one embodiment, the control unit is configured to switch between the control modes based on an input command from an operator, and or the control unit automatically enables switching between the control modes based on a change in operating conditions.
In one embodiment, the motor temperature range and/or the ambient temperature range, and/or the maximum allowable motor pump noise, are constraints in optimizing operation.
In one embodiment, the number of variable displacement pumps is two or more, both of which are driven by the motor shaft.
The present application provides, in another aspect thereof, a hydraulic system comprising:
a motor pump as described above;
an actuator and a control element disposed in a variable pump output circuit of the motor pump; and
an input element configured to be manipulated by an operator to input operational instructions to the control unit, the operational instructions being indicative of at least an updated flow demand;
and the control unit controls the operation of the motor pump based on the operation instruction and the current working state of the motor pump.
The present application provides in another of its aspects a mechanical device, in particular an off-highway device, comprising a hydraulic system as described above or an electric pump as described above.
In one embodiment, the mechanical device is an excavator, in particular a mini excavator, wherein the number of variable displacement pumps in the motor pumps is two, both variable displacement pumps being driven by the motor shaft, wherein one variable displacement pump is used for driving a boom of the excavator and the other variable displacement pump is used for driving a boom and a bucket of the excavator.
According to the application, the motor pump comprises a combination of a variable speed motor and a variable pump, and the efficiency of the hydraulic system is improved and the dynamic response time is shortened by optimizing working parameters.
In addition, by optimizing the working parameters, the optimal working performance of the hydraulic system can be realized, and the flexibility in operation control and structural design of the hydraulic system is widened.
Drawings
The foregoing and other aspects of the present application will be more fully understood from the following detailed description, taken with reference to the accompanying drawings, in which:
FIG. 1 is a fluid circuit diagram of a hydraulic system incorporating a motor pump according to one possible embodiment of the present application, according to one possible embodiment of the present application;
FIG. 2 is a diagram of motor pump control logic according to one possible embodiment of the present application.
Detailed Description
The present application relates generally to a motor pump that incorporates a variable speed motor in combination with a variable displacement pump. The motor pump is suitable for use in a hydraulic system of a machine (e.g., an off-highway vehicle) to provide hydraulic power to an actuator of the machine.
Fig. 1 schematically shows a part of a hydraulic system according to a possible embodiment of the application, in which the motor pump of the application is incorporated. The motor pump comprises a variable speed motor 1 with a motor controller 2, such as a control circuit, a frequency converter or the like. The common motor shaft 3 of the motor 1 drives one or more variable displacement pumps-in the example of fig. 1, the variable displacement pumps include a bidirectional variable displacement pump 4 and a unidirectional variable displacement pump 5. The variable displacement pump has an adjustable displacement (amount of hydraulic oil displaced per revolution). For a continuously variable pump, its displacement is continuously variable (i.e., continuously variable); for a multi-speed variable displacement pump, the displacement may be varied between gears (the displacement per gear is fixed).
The hydraulic system also comprises hydraulic control elements and actuators (not shown in the figures) arranged in the output circuits of the variable displacement pumps 4, 5. Furthermore, pressure sensors 6, 7 are arranged in the output circuits of the variable displacement pumps 4, 5, respectively, for measuring the pressure in the output circuits. The hydraulic system further comprises a control unit 8 which is connected to the input element 9 and is able to receive operating commands input by an operator from the input element 9. The input element 9 may be a lever, an operation panel, a remote controller, or the like. The control unit 8 is also connected to the pressure sensors 6, 7 and is able to receive the detected pressure signals from them. The control unit 8 is also connected to the motor controller 2 and is capable of controlling the operation of the motor 1 via the motor controller 2, including adjusting the rotational speed of the motor shaft 3 of the motor 1, and acquiring operating parameters of the motor 1, including rotational speed, etc. The control unit 8 is also connected to the drives (not shown) of the variable displacement pumps 4, 5 for controlling the respective displacements of the variable displacement pumps 4, 5. The control unit 8 is also connected to the hydraulic control elements and controls the states of these hydraulic control elements in order to achieve the desired action of the actuators.
A typical application of the hydraulic system of figure 1 is in an excavator (particularly a mini-excavator) where the motor 1 is powered by the power battery of the excavator, the variable displacement pump 4 is used to control the action of the big arm of the hydraulic machine and the variable displacement pump 5 is used to control the action of the small arm and the bucket of the hydraulic machine. Furthermore, the cab of the excavator is typically rotatable 360 degrees about a vertical axis. For this purpose, the cabin can be equipped with a separate drive motor or motor pump to drive its rotation; alternatively, in case the motor 1 is sufficiently large, it is also conceivable to use the motor 1 to drive an additional pump for driving the cabin in rotation. The excavator (especially a mini excavator) can also provide driving force by the power battery during running so as to completely eliminate a diesel engine.
The hydraulic system of fig. 1 may also be used in other types of machinery, including other off-highway vehicles. The common drive shaft 3 of the electric motor 1 can drive at least one variable displacement pump, the number of which depends on the specific action requirements, according to the specific application requirements.
Returning to fig. 1, the control unit 8, upon receiving an operation instruction input by an operator via the input element 9, controls the rotational speed of the motor 1 (i.e., the rotational speed of the motor shaft 3) via the motor controller 2, and controls the respective displacements of the variable pumps 4, 5 via the drivers of the variable pumps 4, 5. Control logic within the control unit 8 is used to effect dynamic control of the motor pump performance to achieve the desired performance optimization.
According to a possible embodiment, the control unit 8 is configured to enable a comprehensive optimization of the battery consumption and the motor pump response time. To achieve this comprehensive optimization, an exemplary control logic that the control unit 8 can execute is illustrated in fig. 2, which is described below in connection with fig. 2.
On the one hand, the control unit 8 determines the overall efficiency of the motor pump, as described below.
First, the control unit 8 determines an operation instruction input by the operator through the input element 9. The operation command includes a Flow Demand (Flow Demand) for the variable displacement pumps 4, 5. For example, the gear in which the input element 9 of the lever type is situated corresponds to the respective flow demand. The flow requirement of each variable pump depends on the action to be taken by the corresponding actuator in the mechanical device. Also, the flow demand of each variable displacement pump is the product of the motor speed (revolutions per minute) and the displacement of the variable displacement pump (the amount of hydraulic oil displaced per revolution, typically expressed as a percentage of the maximum displacement).
The control unit 8 determines the motor speed estimate n and the displacement estimate V of the variable displacement pumps 4, 5 on the basis of the flow demand. Furthermore, the control unit 8 acquires the current output pressure P _ act of the variable displacement pumps 4, 5 from the pressure sensors 6, 7.
Next, the control unit 8 determines the variable pump efficiency, including the volumetric efficiency and the hydro-mechanical efficiency, based on the displacement estimation value V and the current output pressure P _ act of the variable pumps 4, 5. According to one embodiment, the variable pump efficiency is determined by a variable pump efficiency lookup table Map 1. The lookup table Map1 contains a plurality of efficiency plots for each variable displacement pump, the curves in each plot representing pump efficiency at a corresponding speed (i.e., motor speed) for pump displacement and output pressure.
Next, the control unit 8 calculates a motor torque estimation value t (t calculation) based on the displacement estimation value V, the current output pressure P _ act, and the efficiency of the variable displacement pumps 4, 5. The motor torque estimate T may be determined by an empirical formula or by a look-up table.
Next, the control unit 8 determines the motor efficiency based on the motor torque estimated value T and the motor rotation speed estimated value n. According to one embodiment, the motor efficiency is determined by a motor efficiency lookup Map 2. The lookup table Map2 contains a motor efficiency graph, wherein the graph represents motor efficiency corresponding to motor torque and rotational speed.
Next, the control unit 8 determines the motor pump total efficiency E _ total (E calculation) based on the motor efficiency and the variable pump efficiency. The overall motor pump efficiency may be determined as a function of the motor efficiency and the pump efficiency for each variable.
On the other hand, the control unit 8 determines the motor pump response time as described below.
The motor pump response time is the time required for the variable displacement pump 4, 5 of the motor pump to change from the current displacement to the flow demand input by the operator via the input element 9.
First, the control unit 8 acquires the current rotational speed n _ act of the motor 1 (e.g. from the motor controller 2) and the current displacement V _ act of the variable displacement pumps 4, 5 (e.g. from the displacement sensors or controllers of the variable displacement pumps 4, 5).
Then, the control unit 8 determines the motor shaft response time t _ draft based on the current output pressure P _ act and the current displacement V _ act of the variable pumps 4, 5, the current rotation speed n _ act of the motor 1, the displacement estimation value V of the variable pumps 4, 5, and the motor rotation speed estimation value n. The motor shaft response time t _ draft may be determined by an empirical formula or by a look-up table.
The control unit 8 determines the response times t _1 and t _2 of the variable pumps 4 and 5, respectively, based on a pump response time look-up table (Curves). The pump response time lookup table includes two graphs, a displacement increase (from 0% displacement to 100% displacement) response time graph and a displacement decrease (from 100% displacement to 0% displacement) response time graph. The response time required to complete a displacement change at different pump output pressures is plotted in each response time graph.
Then, the control unit 8 selects the largest one of the motor shaft response time t _ flush and the response times t _1 and t _2 of the variable pumps 4 and 5, respectively, as the motor pump response time t _ max.
After determining the total motor-pump efficiency E _ total and the motor-pump response time t _ max, the control unit 8 performs an Optimization (Optimization) with these two parameters as Optimization targets and with the motor speed and the pump displacement as Optimization parameters.
For example, the optimization objective is expressed as:
Min[a×E_total+b×t_max]
the optimum motor speed n _ opt to the minimum [ a × E _ total + b × t _ max ] and the respective optimum pump displacement V1_ opt, V2_ opt of the variable displacement pumps 4, 5 are determined by an optimization algorithm (e.g., a traversal optimization algorithm, etc.). For example, by performing multiple iterations of the motor speed estimate n and the displacement estimates V of the variable displacement pumps 4, 5, the optimized motor speed n _ opt and the optimized pump displacements V1_ opt, V2_ opt may be obtained.
Then, the control unit 8 controls the rotation speed of the motor 1 to n _ opt and the displacement amounts of the variable displacement pumps 4 and 5 to V1_ opt and V2_ opt, respectively.
The parameters a and b in the optimization target are adjustable weight values and are changed according to different application scenes. For this purpose, different control modes can be set in the control unit 8, and different weight values a, b can be set in the different control modes.
According to a possible embodiment, at least the following control modes are provided in the control unit 8:
(1) a standard mode, wherein the weight values a, b can be preset by the host plant according to the intended use of the motor pump;
(2) efficiency priority mode, in which the total efficiency of the motor pump (battery consumption) is prioritized, a > b, even b may be set to 0;
(3) dynamic mode, where motor pump reaction speed is prioritized, a < b, even a may be set to 0.
Through the control logic, the control unit 8 realizes the comprehensive optimization of the efficiency and the response time of the motor pump.
It will be appreciated by those skilled in the art that other optimization objectives may be added to the control unit 8. In this case, only the control logic of the control unit 8 needs to be modified.
It will also be appreciated by those skilled in the art that constraints may be added to the control unit 8. For example, temperature constraints may be added to the control unit 8, wherein the control unit 8 keeps the electric machine 1 running with the operating parameters [ speed, torque ] that can achieve the optimization target within a preset motor temperature range and/or ambient temperature range. When the motor temperature range and/or the ambient temperature range is exceeded, for example the temperature is above the upper limit or below the lower limit, the control unit 8 controls the motor 1 to operate at a rotational speed below the set rotational speed limit. The motor temperature may be obtained by the control unit 8 from a temperature sensor inside the motor 1 and the ambient temperature may be obtained by the control unit 8 from an ambient temperature sensor.
As another example, a noise constraint may be added to the control unit 8, wherein the control unit 8 determines a maximum value of the rotation speed by means of the highest allowable noise (the highest of the motor noise and the pump noise), and the control unit 8 keeps the motor 1 operating at a rotation speed lower than the maximum value of the rotation speed.
Other constraints may be envisaged depending on the specific application.
Further, control modes corresponding to these constraints may be added to the control unit 8. For example, a temperature control mode may be added to the control unit 8. After entering the temperature control mode, the control unit 8 keeps the motor 1 running with the operating parameters [ speed, torque ] that enable the highest efficiency within a preset motor temperature range and/or ambient temperature range. When the motor temperature range and/or the ambient temperature range is exceeded, the control unit 8 keeps the electric motor 1 running at a rotational speed below a set rotational speed limit.
As another example, a noise control mode may be added to the control unit 8, wherein the control unit 8 keeps the motor 1 running at a rotational speed below a certain rotational speed maximum.
The operator can control the control unit 8 to switch between various control modes, for example via the input element 9. Alternatively, the control unit 8 may automatically effect switching between the various control modes based on changes in operating conditions (e.g., based on input from the input element 9, detection signals from various detection elements, etc.).
Further, it is understood that when the configuration of the motor pump of the present application and the control logic of the control unit 8 are described above with reference to fig. 1, 2, the pumps of the motor pumps are described as including the variable pumps 4 and 5; however, it will be appreciated by those skilled in the art that the number of variable displacement pumps in the motor pump may be determined based on the particular application, for example including only one variable displacement pump, or 3 or more variable displacement pumps, driven by a common variable speed motor. Compared with the prior art, the variable pump driving device has the advantages that the scheme that more than two variable pumps are driven by the same variable speed motor is more obvious.
Furthermore, it will be appreciated that the optimization objectives in the optimization scheme implemented in the control unit 8 described above are two parameters, the motor pump overall efficiency and the motor pump response time; however, one skilled in the art will appreciate that only one of these two parameters may be selected as an optimization objective based on the particular application. In this case, the step in the control logic of the control unit 8 relating to another parameter can be omitted. Those skilled in the art can readily devise control logic that targets a single parameter for optimization after reading the foregoing description.
To verify the effect of the present application, the applicant compared the battery power consumption of the embodiment of the present application and the comparative example of the conventional art on the excavator. The motor pump in the hydraulic system of the embodiment of the present application includes two variable displacement pumps driven by a common variable speed motor, and the motor pump in the hydraulic system of the comparative example includes two variable displacement pumps driven by a common fixed speed motor. The data in the table below are motor speed and battery power consumption for one operating condition.
Figure BDA0002983785030000081
By comparison, the total energy consumption of the motor pump of the present application in the operation of the excavator is reduced compared to various operation modes of the prior art.
The present application further contemplates a hydraulic system incorporating the motor pump described above, as well as a mechanical device, such as an off-highway device, such as an excavator (particularly a mini-excavator), employing such a hydraulic system. The mechanical device may employ a power battery as the primary power source that powers the motor pump as well as other components in the hydraulic system. For off-highway devices, the power battery can be used as a power source for driving the off-highway device to run. For mechanical devices with a power cell as the primary power source, it may be advantageous to avoid the limits imposed on emissions.
According to the application, the motor pump is composed of the variable-speed motor and one or more variable pumps, and the control unit capable of optimizing the performance of the motor pump is combined, so that the system efficiency can be improved, and the energy consumption of the battery can be reduced.
Furthermore, the control unit can be optimized comprehensively for different objectives to achieve an increase of different properties of the motor pump or the hydraulic system or the mechanical device, which also provides greater flexibility (freedom) for the design of the motor pump, the hydraulic system, the mechanical device.
Although the present application has been described herein with reference to specific exemplary embodiments, the scope of the present application is not intended to be limited to the details shown. Various modifications may be made to these details without departing from the underlying principles of the application.

Claims (11)

1. An electric motor pump comprising:
a variable speed motor (1) having a motor controller (2) and a motor shaft (3);
at least one variable displacement pump (4, 5) driven by the motor shaft; and
a control unit (8) configured to:
acquiring the current working state of a motor pump, wherein the current working state at least comprises the current rotating speed of a variable speed motor, the current displacement and the output pressure of a variable pump;
obtaining an updated flow demand for the motor pump;
executing optimization operation based on the updated flow demand and the current working state of the motor pump, wherein the optimization operation takes the total efficiency and/or the response time of the motor pump as optimization targets and takes the motor speed and the variable pump displacement as optimization variables to obtain the optimized motor speed and the optimized variable pump displacement; and
controlling the speed of the variable speed motor to an optimized motor speed and controlling the displacement of the variable displacement pump to an optimized displacement of the variable displacement pump.
2. The motor pump of claim 1, wherein the optimization objectives are motor pump overall efficiency and motor pump response time, and are assigned respective weight values that can be varied for specific operating requirements.
3. The motor pump of claim 2, wherein at least the following control modes are provided in the control unit:
a standard mode, in which two weight values are preset according to the intended use of the motor pump;
an efficiency priority mode in which a weighted value of a total efficiency of the motor pump is greater than a weighted value of a response time of the motor pump;
a dynamic mode wherein a weighted value of motor pump response speed is greater than a weighted value of motor pump total efficiency.
4. The motor pump of claim 3, wherein the control unit further includes a temperature control mode, wherein the control unit controls the motor pump to operate at the optimized motor speed and variable pump displacement within a predetermined motor temperature range and/or ambient temperature range, and maintains the variable speed motor operating at a speed below a set speed limit when the motor temperature range and/or ambient temperature range is exceeded.
5. The motor pump of claim 3 or 4 wherein a noise control mode is further provided in the control unit, wherein the control unit determines a maximum rotational speed based on the maximum allowable motor pump noise and maintains the variable speed motor operating at a rotational speed below the maximum rotational speed.
6. The electric motor pump of any of claims 3 to 5, wherein the control unit is configured to switch between control modes based on operator input commands, and or the control unit automatically effects switching between control modes based on changes in operating conditions.
7. The motor pump of any of claims 1 to 3, wherein a motor temperature range and/or an ambient temperature range, and/or a maximum allowable motor pump noise, is a constraint in optimizing operation.
8. The motor pump of any one of claims 1 to 7, wherein the number of variable pumps is two or more, both variable pumps being driven by the motor shaft.
9. A hydraulic system, comprising:
the motor pump of any one of claims 1 to 8;
an actuator and a control element disposed in a variable pump output circuit of the motor pump; and
an input element (9) configured to be manipulated by an operator to input operational instructions to the control unit, the operational instructions being indicative of at least an updated flow demand;
and the control unit controls the operation of the motor pump based on the operation instruction and the current working state of the motor pump.
10. A mechanical device, in particular an off-highway device, comprising a hydraulic system according to claim 9.
11. The machine as claimed in claim 10, wherein the machine is an excavator, in particular a mini excavator, wherein the number of variable displacement pumps in the motor pumps is two, both variable displacement pumps being driven by the motor shaft, one variable displacement pump being used to drive the big arm of the excavator and the other variable displacement pump being used to drive the small arm and the bucket of the excavator.
CN202110294437.0A 2021-03-19 2021-03-19 Motor pump, hydraulic system and mechanical equipment Pending CN115111210A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN202110294437.0A CN115111210A (en) 2021-03-19 2021-03-19 Motor pump, hydraulic system and mechanical equipment
PCT/CN2022/079894 WO2022193998A1 (en) 2021-03-19 2022-03-09 Motor pump, hydraulic system, and mechanical device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110294437.0A CN115111210A (en) 2021-03-19 2021-03-19 Motor pump, hydraulic system and mechanical equipment

Publications (1)

Publication Number Publication Date
CN115111210A true CN115111210A (en) 2022-09-27

Family

ID=83321524

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110294437.0A Pending CN115111210A (en) 2021-03-19 2021-03-19 Motor pump, hydraulic system and mechanical equipment

Country Status (2)

Country Link
CN (1) CN115111210A (en)
WO (1) WO2022193998A1 (en)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4335403C1 (en) * 1993-10-18 1994-12-15 Karl Hehl Hydraulic device
CN101993006B (en) * 2010-10-12 2012-07-04 三一汽车起重机械有限公司 Automobile crane and energy-saving control method and energy-saving control system thereof
CN102493953B (en) * 2012-01-05 2014-10-15 三一汽车起重机械有限公司 Energy-saving control system, truck crane and energy-saving control method
CN203516044U (en) * 2013-10-14 2014-04-02 湖南长昊机械有限公司 Control device of concrete boom pump
CN109372832B (en) * 2018-12-21 2020-01-03 合肥工业大学 Energy consumption optimization method for bivariate hydraulic system under working condition change
SE544986C2 (en) * 2019-04-05 2023-02-21 Epiroc Rock Drills Ab Method and system for controlling operation of a hydraulic system of a drilling rig

Also Published As

Publication number Publication date
WO2022193998A1 (en) 2022-09-22

Similar Documents

Publication Publication Date Title
KR101550328B1 (en) A method and a system for operating a working machine
RU2499153C2 (en) Control over drive engine rpm
JP5119349B2 (en) Work vehicle control device and control method thereof
JP2013538310A (en) Control system with load adjustable economy mode
US20160340871A1 (en) Engine and Pump Control Device and Working Machine
KR20140031401A (en) Hybrid working vehicle
WO2010030830A1 (en) Method of controlling an electro-hydraulic actuator system having multiple functions
JP5074571B2 (en) Work vehicle and control method of work vehicle
WO2012046788A1 (en) Hybrid working machine
CN1854539A (en) Apparatus and method for controlling a pump flow of heavy construction equipment
US9273615B2 (en) Control device of internal combustion engine, work machine and control method of internal combustion engine
US11028558B2 (en) Work vehicle and control method for work vehicle
CN107429629B (en) Construction machine
US10160439B2 (en) Power efficiency control mechanism for a working machine
WO2013109512A1 (en) System and method for controlling engine torque load
CN115111210A (en) Motor pump, hydraulic system and mechanical equipment
CN113939659A (en) Hydraulic circuit architecture with improved operating efficiency
KR20180004173A (en) Apparatus and method for controlling a work machine
EP1925520A1 (en) Method for controlling a powertrain and associated powertrain
CN110905672B (en) Real-time power matching method of hydraulic system adapting to different rotating speeds of engine
JP6077365B2 (en) Engine control device and hybrid construction machine equipped with the same
JP5309257B2 (en) Work vehicle control device and control method thereof
WO2017010522A1 (en) Work vehicle
CN111962599B (en) Compound driving system and control method of electric excavator
EP4347345A1 (en) System and method for controlling engine operations

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination