EP3467307A1 - Pressure control of hydraulic system with electric motor - Google Patents

Pressure control of hydraulic system with electric motor Download PDF

Info

Publication number
EP3467307A1
EP3467307A1 EP17194730.2A EP17194730A EP3467307A1 EP 3467307 A1 EP3467307 A1 EP 3467307A1 EP 17194730 A EP17194730 A EP 17194730A EP 3467307 A1 EP3467307 A1 EP 3467307A1
Authority
EP
European Patent Office
Prior art keywords
motor
hydraulic
drive unit
electric motor
torque value
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.)
Granted
Application number
EP17194730.2A
Other languages
German (de)
French (fr)
Other versions
EP3467307B1 (en
Inventor
Per Sundqvist
Thomas Carlsson
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.)
Automation Press and Tooling AP&T AB
Original Assignee
Automation Press and Tooling AP&T AB
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 Automation Press and Tooling AP&T AB filed Critical Automation Press and Tooling AP&T AB
Priority to EP17194730.2A priority Critical patent/EP3467307B1/en
Priority to ES17194730T priority patent/ES2875355T3/en
Priority to HUE17194730A priority patent/HUE054669T2/en
Priority to PT171947302T priority patent/PT3467307T/en
Priority to PL17194730T priority patent/PL3467307T3/en
Priority to PCT/EP2018/076907 priority patent/WO2019068762A1/en
Publication of EP3467307A1 publication Critical patent/EP3467307A1/en
Application granted granted Critical
Publication of EP3467307B1 publication Critical patent/EP3467307B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04BPOSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00Control, 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
    • F04B49/06Control using electricity
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04BPOSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B17/00Pumps characterised by combination with, or adaptation to, specific driving engines or motors
    • F04B17/03Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors

Definitions

  • the present disclosure relates to a hydraulic system, and especially to an arrangement of pressure control in the hydraulic system.
  • a hydraulic device such as a hydraulic cylinder
  • a hydraulic pump driven by an electric motor, in fluid connection via a pipe with a pressure chamber of the hydraulic cylinder.
  • the pump may increase the pressure in the pressure chamber, and thereby moving the cylinder piston.
  • a pressure valve is arranged on the pipe between the hydraulic pump and the hydraulic cylinder.
  • the pressure valve may be controlled to open and thereby release pressure in the pipe and the connected pressure chamber.
  • the pressure valve may for instance be controlled to open when the pressure in the pipe reaches a predetermined threshold.
  • the pressure in the pressure chamber of the hydraulic cylinder may thereby be controlled using the pressure valve.
  • Such system using a pressure valve to control the pressure is however limited in the control of the pressure.
  • EP1882534 One solution offering further controlling functions is disclosed in EP1882534 , wherein a pressure sensor is arranged to detect the pressure in the pressure chamber of the hydraulic cylinder. The detected pressure is compared to a predetermined desired pressure, and the motor/pump is controlled to increase or decrease the pressure to reach the desired pressure. Such system is however slow and complicated, which may further affect the accuracy of the pressure control.
  • a hydraulic system comprising a hydraulic device, a hydraulic pump in fluid connection with the hydraulic device, an electric motor arranged to drive the hydraulic pump, and a motor drive unit configured to control the operation of the electric motor.
  • the hydraulic system further comprises a control unit configured to provide a desired motor torque value to the motor drive unit.
  • the motor drive unit is configured to control the operation of the electric motor to a desired torque based on the desired motor torque value.
  • the present invention provides a single control loop in which the control unit may provide a desired motor torque value.
  • the desired motor torque value may correspond to a desired pressure value in the hydraulic device.
  • the desired motor torque value may be used by the motor drive unit as a reference value toward which the torque of the electric motor may be controlled. This may be controlled by the motor drive unit by controlling the current, torque or other parameters to the electric motor. By controlling the torque of the electric motor, the pressure provided by the hydraulic pump may be controlled. An increased set pressure may provide an increased torque in the electric motor.
  • the motor drive unit may increase the current to the electric motor to increase the torque. This may consequently increase the pressure in the hydraulic device following an increased speed of the pump.
  • a decreased set pressure may provide a decreased torque in the servo motor.
  • the motor drive unit may decrease the current to the servo motor to decrease the torque. This may consequently decrease the pressure in the hydraulic device following a decreased speed of the pump.
  • control unit may provide instructions to the motor drive unit to indirectly control the pressure in the hydraulic device by providing a desired motor torque value.
  • the motor drive unit may get feedback of the present torque in the electric motor by the present current consumption of the electric motor. This may further provide an indirect feedback of the fluid pressure in the system.
  • the control unit may be configured to relate a desired operation of the hydraulic device to a certain motor torque of the electric motor.
  • the desired operation of the hydraulic device may be initiated by a manual operation by a user, or by an automatically controlled operation.
  • the electric motor may be a servo motor, a reluctance motor or an asynchronous motor.
  • the hydraulic device may be a hydraulic cylinder.
  • the hydraulic system may be a hydraulic press system.
  • the motor drive unit may be synchronized with the electric motor in the present hydraulic system in order to relate the driving of the electric motor to the torque control thereof.
  • the control unit may then use the torque value sent to the motor drive unit to achieve a desired pressure and operation of the hydraulic device.
  • the hydraulic system may comprise a plurality of hydraulic devices, each pressurized by a hydraulic pump driven by an electric motor, which is controlled by a motor drive unit.
  • Each motor drive unit may receive a desired motor torque value from the control unit.
  • Each motor drive unit may receive an individually set desired motor torque value from the control unit.
  • all motor drive units may receive the same desired motor torque value. In a system comprising more than one hydraulic pump, a more complex pressure control may be possible.
  • two or more hydraulic pumps may be provided to together provide an aggregated hydraulic pressure to the hydraulic device.
  • all motor drive units may receive the same desired motor torque value to provide all electric motors be operated with the same torque. If all hydraulic pumps are similar, each pump may then also provide similar portions to the total pressure. Alternatively, one hydraulic pump may be desired to provide a larger portion of the aggregated pressure.
  • the motor drive unit for that electric motor and pump may thereby receive a different desired motor torque value than the motor drive units for the other pumps.
  • the motor drive unit that receives a different desired motor torque value may further receive a desired motor rpm value for the electric motor.
  • the rpm of that electric motor may be set together with the torque in order to avoid that the electric motor reverse due to a lower torque value than for the other electric motors.
  • the motor drive unit that received the desired motor rpm value may control the electric motor to operate at the desired rpm and with the desired torque.
  • the hydraulic pump in direct connection with the electric motor may thereby operate at the same rpm as the electric motor.
  • the system may comprise two hydraulic pumps operable in opposite directions to enable a low aggregated pressure without operating a pump at low speed risking damage to the pump and electric motor.
  • the motor drive units operating the electric motors driving the pumps may thereby receive different desired motor torque values and/or motor rpm values to achieve a desired aggregated pressure to the hydraulic device.
  • a method of controlling pressure in a hydraulic device in a hydraulic system comprises the step of providing a hydraulic pump in fluid connection with the hydraulic device, wherein the hydraulic pump is driven by an electric motor, providing a desired motor torque value to a motor drive unit controlling the operation of the electric motor, and controlling the torque of the electric motor via the motor drive unit to a desired torque based on the desired motor torque value.
  • Fig. 1 illustrates a hydraulic system 1 comprising a hydraulic device in the form of a hydraulic cylinder 10.
  • the hydraulic cylinder 10 comprises a pressure chamber 12 and a piston 14.
  • the pressure in the pressure chamber 12 controls the position and movement of the piston 14.
  • the pressure of the pressure chamber 12 is provided by a hydraulic pump 20 in fluid connection with the pressure chamber 12 via a pipe 16.
  • the hydraulic pump 20 receives incoming pressure fluid from an incoming pipe 18.
  • the pressure fluid is pressurized by the hydraulic pump 20 and supplied to the pipe 16.
  • the hydraulic pump 20 is driven by an electric motor 30 via a drive shaft 32.
  • the speed of the electric motor 30 controls the speed of the hydraulic pump 20.
  • the operation of the electric motor 30 is controlled by a motor drive unit 40.
  • the drive unit 40 supplies power to the electric motor 30.
  • the drive unit 40 controls the torque of the electric motor 30 by controlling the supplied current, torque or other parameters to the electric motor 30. By monitoring and controlling the current, torque or other parameters supplied to and consumed by the electric motor 30, the torque of the electric motor 30 is controlled.
  • the drive unit 40 is communicatively connected to a control unit 50.
  • the control unit 50 transmits a desired torque value for the electric motor 30 to the drive unit 40.
  • the desired torque value corresponds to a motor torque determined to provide a desired pressure in the pressure chamber 12, and further a desired operation of the hydraulic cylinder 10.
  • the control unit 50 is configured to provide a desired torque value that is determined based on a desired operation of the hydraulic cylinder 10. The desired operation is provided either from a manual operation by a user of the hydraulic system 1, or from an automatic operation controlling the hydraulic cylinder 10.
  • the performance of the electric motor 30, hydraulic pump 20 together with the hydraulic cylinder 10 may be calibrated to provide a system in which the operation of the hydraulic cylinder 10 can be predetermined based on a specific torque of the electric motor 30.
  • the operation of the hydraulic cylinder 10 can be controlled by the control unit 50 by setting a desired torque value for the electric motor 30. No slow continuous feedback of the pressure in the pressure chamber 12 or the pipe 16 is thereby needed during operation of the hydraulic system 1.
  • a pressure valve (not shown) can be arranged between the hydraulic pump 20 and the hydraulic cylinder 10, which is configured to release pressure from the pipe 16 when the pressure therein reaches a predetermined threshold. Momentary peaks in the pressure is thereby taken care of by the pressure valve.
  • Fig. 2 illustrates a hydraulic press system 1' according to an embodiment, comprising two hydraulic pumps 20a, 20b, each driven by an electric motor 30a, 30b via a shaft 32a, 32b.
  • the electric motors 30a, 30b are controlled by a respective drive unit 40a, 40b. Both drive units 40a, 40b receives a desired motor torque value from the control unit 50.
  • Each drive unit 40a, 40b control the respective electric motor 30a, 30b based on the received desired motor torque value.
  • the received motor torque value and/or motor rpm value may be the same to both drive units 40a, 40b, or individually set by the control unit 50, as discussed above.
  • a desired aggregated pressure in the pipe 16 to the hydraulic cylinder 10 can thereby be achieved.
  • Fig. 3 illustrates a flow chart of a method 100 according an embodiment of the invention.
  • a hydraulic system 1 is provided comprising the hydraulic cylinder 10 in fluid connection with the hydraulic pump 20.
  • the hydraulic pump 20 is driven by the electric motor 30, which in turn is controlled by the motor drive unit 40.
  • a desired motor torque value is provided 104 to the motor drive unit.
  • the motor torque is controlled 106 based on the received desired motor torque value.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Electric Motors In General (AREA)

Abstract

The present invention relates to a hydraulic system (1), wherein the system comprises a hydraulic device (10), a hydraulic pump (20) in fluid connection with the pressure chamber of the hydraulic device, an electric motor (30) arranged to drive the hydraulic pump, and a motor drive unit (40) configured to control the operation of the electric motor. The hydraulic system further comprises a control unit (50) configured to provide a desired motor torque value to the motor drive unit. The motor drive unit is configured to control the operation of the electric motor to a desired torque based on the desired motor torque value. The present invention further relates to a method of controlling pressure in a hydraulic device (10) in a hydraulic system (1).

Description

    Technical Field
  • The present disclosure relates to a hydraulic system, and especially to an arrangement of pressure control in the hydraulic system.
  • Background
  • In a hydraulic system, a hydraulic device, such as a hydraulic cylinder, is controlled by a hydraulic pump, driven by an electric motor, in fluid connection via a pipe with a pressure chamber of the hydraulic cylinder. The pump may increase the pressure in the pressure chamber, and thereby moving the cylinder piston.
  • In one conventional solution, a pressure valve is arranged on the pipe between the hydraulic pump and the hydraulic cylinder. The pressure valve may be controlled to open and thereby release pressure in the pipe and the connected pressure chamber. The pressure valve may for instance be controlled to open when the pressure in the pipe reaches a predetermined threshold. The pressure in the pressure chamber of the hydraulic cylinder may thereby be controlled using the pressure valve. Such system using a pressure valve to control the pressure is however limited in the control of the pressure.
  • One solution offering further controlling functions is disclosed in EP1882534 , wherein a pressure sensor is arranged to detect the pressure in the pressure chamber of the hydraulic cylinder. The detected pressure is compared to a predetermined desired pressure, and the motor/pump is controlled to increase or decrease the pressure to reach the desired pressure. Such system is however slow and complicated, which may further affect the accuracy of the pressure control.
  • Consequently, there is a need for a hydraulic system with a faster and more accurate pressure control.
  • Summary
  • It is an object of the present invention to provide an improved solution that alleviates the mentioned drawbacks with present devices. The invention is defined by the appended independent claims, with embodiments being set forth in the appended dependent claims, in the following description and in the drawings.
  • According to a first aspect of the present invention, a hydraulic system is provided, wherein the system comprises a hydraulic device, a hydraulic pump in fluid connection with the hydraulic device, an electric motor arranged to drive the hydraulic pump, and a motor drive unit configured to control the operation of the electric motor. The hydraulic system further comprises a control unit configured to provide a desired motor torque value to the motor drive unit. The motor drive unit is configured to control the operation of the electric motor to a desired torque based on the desired motor torque value.
  • By controlling the torque of the electric motor to a desired motor torque value to control the pressure in the system, a very fast and accurate pressure control may be provided. One reason this may be provided is that it is less complex, since no external pressure sensors or load cells for feedback is needed. The present invention may further not give any extra load to the control system.
  • The present invention provides a single control loop in which the control unit may provide a desired motor torque value. The desired motor torque value may correspond to a desired pressure value in the hydraulic device. The desired motor torque value may be used by the motor drive unit as a reference value toward which the torque of the electric motor may be controlled. This may be controlled by the motor drive unit by controlling the current, torque or other parameters to the electric motor. By controlling the torque of the electric motor, the pressure provided by the hydraulic pump may be controlled. An increased set pressure may provide an increased torque in the electric motor. Hence, if the desired motor torque value received by the motor drive unit is greater than the present torque, the motor drive unit may increase the current to the electric motor to increase the torque. This may consequently increase the pressure in the hydraulic device following an increased speed of the pump. A decreased set pressure may provide a decreased torque in the servo motor. Hence, if the desired motor torque value received by the motor drive unit is less than the present torque, the motor drive unit may decrease the current to the servo motor to decrease the torque. This may consequently decrease the pressure in the hydraulic device following a decreased speed of the pump.
  • Depending on the desired operation of the hydraulic device, the control unit may provide instructions to the motor drive unit to indirectly control the pressure in the hydraulic device by providing a desired motor torque value. The motor drive unit may get feedback of the present torque in the electric motor by the present current consumption of the electric motor. This may further provide an indirect feedback of the fluid pressure in the system.
  • The control unit may be configured to relate a desired operation of the hydraulic device to a certain motor torque of the electric motor. The desired operation of the hydraulic device may be initiated by a manual operation by a user, or by an automatically controlled operation.
  • The electric motor may be a servo motor, a reluctance motor or an asynchronous motor. The hydraulic device may be a hydraulic cylinder. The hydraulic system may be a hydraulic press system.
  • At installation of the hydraulic system, the motor drive unit may be synchronized with the electric motor in the present hydraulic system in order to relate the driving of the electric motor to the torque control thereof. The control unit may then use the torque value sent to the motor drive unit to achieve a desired pressure and operation of the hydraulic device.
  • In one embodiment, the hydraulic system may comprise a plurality of hydraulic devices, each pressurized by a hydraulic pump driven by an electric motor, which is controlled by a motor drive unit. Each motor drive unit may receive a desired motor torque value from the control unit. Each motor drive unit may receive an individually set desired motor torque value from the control unit. Alternatively, all motor drive units may receive the same desired motor torque value. In a system comprising more than one hydraulic pump, a more complex pressure control may be possible.
  • As a first example, two or more hydraulic pumps may be provided to together provide an aggregated hydraulic pressure to the hydraulic device. Depending on the desired pressure, all motor drive units may receive the same desired motor torque value to provide all electric motors be operated with the same torque. If all hydraulic pumps are similar, each pump may then also provide similar portions to the total pressure. Alternatively, one hydraulic pump may be desired to provide a larger portion of the aggregated pressure. The motor drive unit for that electric motor and pump may thereby receive a different desired motor torque value than the motor drive units for the other pumps. The motor drive unit that receives a different desired motor torque value may further receive a desired motor rpm value for the electric motor. The rpm of that electric motor may be set together with the torque in order to avoid that the electric motor reverse due to a lower torque value than for the other electric motors. The motor drive unit that received the desired motor rpm value may control the electric motor to operate at the desired rpm and with the desired torque. The hydraulic pump in direct connection with the electric motor may thereby operate at the same rpm as the electric motor.
  • As a second example, the system may comprise two hydraulic pumps operable in opposite directions to enable a low aggregated pressure without operating a pump at low speed risking damage to the pump and electric motor. The motor drive units operating the electric motors driving the pumps may thereby receive different desired motor torque values and/or motor rpm values to achieve a desired aggregated pressure to the hydraulic device.
  • According to a second aspect of the invention, a method of controlling pressure in a hydraulic device in a hydraulic system is provided. The method comprises the step of providing a hydraulic pump in fluid connection with the hydraulic device, wherein the hydraulic pump is driven by an electric motor, providing a desired motor torque value to a motor drive unit controlling the operation of the electric motor, and controlling the torque of the electric motor via the motor drive unit to a desired torque based on the desired motor torque value.
  • Such method provides advantages and may be used in embodiments as discussed for the hydraulic system above.
  • Brief Description of the Drawings
  • The invention will in the following be described in more detail with reference to the enclosed drawings, wherein:
    • Fig. 1 show a schematic block view of a hydraulic system according to an embodiment of the invention;
    • Fig. 2 show a schematic block view of a hydraulic system according to an embodiment of the invention; and
    • Fig. 3 show a flowchart of a method according to an embodiment of the invention.
    Description of Embodiments
  • The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements.
  • Fig. 1 illustrates a hydraulic system 1 comprising a hydraulic device in the form of a hydraulic cylinder 10. The hydraulic cylinder 10 comprises a pressure chamber 12 and a piston 14. The pressure in the pressure chamber 12 controls the position and movement of the piston 14. The pressure of the pressure chamber 12 is provided by a hydraulic pump 20 in fluid connection with the pressure chamber 12 via a pipe 16. The hydraulic pump 20 receives incoming pressure fluid from an incoming pipe 18. The pressure fluid is pressurized by the hydraulic pump 20 and supplied to the pipe 16.
  • The hydraulic pump 20 is driven by an electric motor 30 via a drive shaft 32. The speed of the electric motor 30 controls the speed of the hydraulic pump 20. The operation of the electric motor 30 is controlled by a motor drive unit 40. The drive unit 40 supplies power to the electric motor 30. The drive unit 40 controls the torque of the electric motor 30 by controlling the supplied current, torque or other parameters to the electric motor 30. By monitoring and controlling the current, torque or other parameters supplied to and consumed by the electric motor 30, the torque of the electric motor 30 is controlled.
  • The drive unit 40 is communicatively connected to a control unit 50. The control unit 50 transmits a desired torque value for the electric motor 30 to the drive unit 40. The desired torque value corresponds to a motor torque determined to provide a desired pressure in the pressure chamber 12, and further a desired operation of the hydraulic cylinder 10. The control unit 50 is configured to provide a desired torque value that is determined based on a desired operation of the hydraulic cylinder 10. The desired operation is provided either from a manual operation by a user of the hydraulic system 1, or from an automatic operation controlling the hydraulic cylinder 10.
  • When the hydraulic system 1 is set up, the performance of the electric motor 30, hydraulic pump 20 together with the hydraulic cylinder 10 may be calibrated to provide a system in which the operation of the hydraulic cylinder 10 can be predetermined based on a specific torque of the electric motor 30. When this has been done, the operation of the hydraulic cylinder 10 can be controlled by the control unit 50 by setting a desired torque value for the electric motor 30. No slow continuous feedback of the pressure in the pressure chamber 12 or the pipe 16 is thereby needed during operation of the hydraulic system 1.
  • In one embodiment, a pressure valve (not shown) can be arranged between the hydraulic pump 20 and the hydraulic cylinder 10, which is configured to release pressure from the pipe 16 when the pressure therein reaches a predetermined threshold. Momentary peaks in the pressure is thereby taken care of by the pressure valve.
  • Fig. 2 illustrates a hydraulic press system 1' according to an embodiment, comprising two hydraulic pumps 20a, 20b, each driven by an electric motor 30a, 30b via a shaft 32a, 32b. The electric motors 30a, 30b are controlled by a respective drive unit 40a, 40b. Both drive units 40a, 40b receives a desired motor torque value from the control unit 50. Each drive unit 40a, 40b control the respective electric motor 30a, 30b based on the received desired motor torque value. The received motor torque value and/or motor rpm value may be the same to both drive units 40a, 40b, or individually set by the control unit 50, as discussed above. A desired aggregated pressure in the pipe 16 to the hydraulic cylinder 10 can thereby be achieved.
  • Fig. 3 illustrates a flow chart of a method 100 according an embodiment of the invention. In a first step 102, a hydraulic system 1 is provided comprising the hydraulic cylinder 10 in fluid connection with the hydraulic pump 20. The hydraulic pump 20 is driven by the electric motor 30, which in turn is controlled by the motor drive unit 40. Further, a desired motor torque value is provided 104 to the motor drive unit. Finally, the motor torque is controlled 106 based on the received desired motor torque value.
  • In the drawings and specification, there have been disclosed preferred embodiments and examples of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being set forth in the following claims.

Claims (12)

  1. A hydraulic system (1) comprising
    a hydraulic device (10);
    a hydraulic pump (20) in fluid connection with the hydraulic device;
    an electric motor (30) arranged to drive the hydraulic pump;
    a motor drive unit (40) configured to control the operation of the electric motor;
    characterized in that
    the hydraulic system further comprises a control unit (50) configured to provide a desired motor torque value to the motor drive unit, and
    wherein the motor drive unit is configured to control the operation of the electric motor to a desired torque based on the desired motor torque value.
  2. The hydraulic system according to claim 1, wherein the control unit (50) is configured to provide the desired motor torque value based on a desired operation of the hydraulic device (10).
  3. The hydraulic system according to claim 1 or 2, wherein the hydraulic system comprises a plurality of hydraulic pumps (20), each driven by an electric motor (30) controlled by a motor drive unit (40), wherein the control unit is configured to provide a desired motor torque value to each motor drive unit.
  4. The hydraulic system according to claim 3, wherein the control unit (50) is configured to provide similar desired motor torque values to all motor drive units (40).
  5. The hydraulic system according to claim 3, wherein the control unit (50) is configured to provide an individual desired motor torque value to each motor drive unit (40).
  6. The hydraulic system according to claim 5, wherein the control unit (50) further is configured to provide a desired motor rpm value to at least one motor drive unit (40).
  7. A method (100) of controlling pressure in a hydraulic device (10) in a hydraulic system (1), the method comprising the steps of:
    providing (102) a hydraulic pump (20) in fluid connection with the hydraulic device, wherein the hydraulic pump is driven by an electric motor (30),
    providing (104) a desired motor torque value to a motor drive unit (40) controlling the operation of the electric motor, and
    controlling (106) the torque of the motor via the motor drive unit to a desired torque based on the desired motor torque value.
  8. The method according to claim 7, wherein the desired motor torque value is provided based on a desired operation of the hydraulic device (10).
  9. The method according to claim 7 or 8, wherein a plurality of hydraulic pumps (20), each driven by an electric motor (30) controlled by a motor drive unit (40), are provided, and wherein the step (104) of providing a desired motor torque value comprises providing a desired motor torque value to each motor drive unit.
  10. The method according to claim 9, wherein similar desired motor torque values are provided to all motor drive units (40).
  11. The method according to claim 8, wherein an individual desired motor torque value is provided to each motor drive unit (40).
  12. The method according to claim 11, wherein a desired motor rpm value is provided to at least one motor drive unit (40).
EP17194730.2A 2017-10-04 2017-10-04 Pressure control of hydraulic system with electric motor Active EP3467307B1 (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
EP17194730.2A EP3467307B1 (en) 2017-10-04 2017-10-04 Pressure control of hydraulic system with electric motor
ES17194730T ES2875355T3 (en) 2017-10-04 2017-10-04 Pressure control of an electric motor hydraulic system
HUE17194730A HUE054669T2 (en) 2017-10-04 2017-10-04 Pressure control of hydraulic system with electric motor
PT171947302T PT3467307T (en) 2017-10-04 2017-10-04 Pressure control of hydraulic system with electric motor
PL17194730T PL3467307T3 (en) 2017-10-04 2017-10-04 Pressure control of hydraulic system with electric motor
PCT/EP2018/076907 WO2019068762A1 (en) 2017-10-04 2018-10-03 Pressure control of hydraulic system with electric motor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP17194730.2A EP3467307B1 (en) 2017-10-04 2017-10-04 Pressure control of hydraulic system with electric motor

Publications (2)

Publication Number Publication Date
EP3467307A1 true EP3467307A1 (en) 2019-04-10
EP3467307B1 EP3467307B1 (en) 2021-04-21

Family

ID=60021944

Family Applications (1)

Application Number Title Priority Date Filing Date
EP17194730.2A Active EP3467307B1 (en) 2017-10-04 2017-10-04 Pressure control of hydraulic system with electric motor

Country Status (6)

Country Link
EP (1) EP3467307B1 (en)
ES (1) ES2875355T3 (en)
HU (1) HUE054669T2 (en)
PL (1) PL3467307T3 (en)
PT (1) PT3467307T (en)
WO (1) WO2019068762A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5281774A (en) * 1990-11-20 1994-01-25 Mitsubishi Denki Kabushiki Kaisha Drive control unit for hydraulic elevator
EP1882534A1 (en) 2005-05-16 2008-01-30 Aida Engineering, Ltd. Die cushion device for press machine
US20140219822A1 (en) * 2011-06-16 2014-08-07 Robert Bosch Gmbh Method and device for controlling a torque of an electric motor of an electro-hydraulic system
US20160084274A1 (en) * 2014-09-23 2016-03-24 Thomas Afshari System to pump fluid and control thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5281774A (en) * 1990-11-20 1994-01-25 Mitsubishi Denki Kabushiki Kaisha Drive control unit for hydraulic elevator
EP1882534A1 (en) 2005-05-16 2008-01-30 Aida Engineering, Ltd. Die cushion device for press machine
US20140219822A1 (en) * 2011-06-16 2014-08-07 Robert Bosch Gmbh Method and device for controlling a torque of an electric motor of an electro-hydraulic system
US20160084274A1 (en) * 2014-09-23 2016-03-24 Thomas Afshari System to pump fluid and control thereof

Also Published As

Publication number Publication date
PT3467307T (en) 2021-06-04
EP3467307B1 (en) 2021-04-21
ES2875355T3 (en) 2021-11-10
HUE054669T2 (en) 2021-09-28
PL3467307T3 (en) 2021-10-25
WO2019068762A1 (en) 2019-04-11

Similar Documents

Publication Publication Date Title
US20220025910A1 (en) Self-contained energy efficient hydraulic actuator system
EP4209686A1 (en) Pressure-compensation hydraulic pump, rotation speed control system and control method, and engineering machinery
JP5473607B2 (en) Electrohydraulic control device
US10352309B2 (en) Fluid pressure producing method and fluid pressure producing device
US20160340871A1 (en) Engine and Pump Control Device and Working Machine
GB2469016A (en) Electrically driven hydraulic actuator
EP2918735A2 (en) Hydraulic driving apparatus for working machine
JP4194868B2 (en) Hydraulic control system
CN109914515B (en) Swing operation control system and method
EP3467307B1 (en) Pressure control of hydraulic system with electric motor
CN107269832B (en) Hydrostatic transmission and vehicle having such a hydrostatic transmission
US8973605B2 (en) Actuating device for housed or housingless valves
EP3249111B1 (en) Method for controlling flow rate of hydraulic pump of construction machine
CN203305487U (en) Energy-saving servo control system
CN102016187A (en) Method of controlling a hydraulic system
EP4123174A1 (en) Displacement pump pressure feedback control and method of control
JP2008232045A (en) Inverter driven hydraulic device
JP2019183727A (en) Inverter drive hydraulic device
CN116964282A (en) Electric motor control for high performance hydraulic systems
CN112483426B (en) Control method, oil pump and control system
JP2019183944A (en) Inverter drive hydraulic device
EP3255215B1 (en) Hydraulic pump control apparatus for construction equipment and control method thereof
JPS62220701A (en) Variable delivery pump
CN111102392B (en) Control system and control method of electric valve
CN208040791U (en) Hydraulic servo energy conserving system

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20190911

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: GRANT OF PATENT IS INTENDED

INTG Intention to grant announced

Effective date: 20210202

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE PATENT HAS BEEN GRANTED

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602017036997

Country of ref document: DE

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 1384905

Country of ref document: AT

Kind code of ref document: T

Effective date: 20210515

REG Reference to a national code

Ref country code: RO

Ref legal event code: EPE

REG Reference to a national code

Ref country code: PT

Ref legal event code: SC4A

Ref document number: 3467307

Country of ref document: PT

Date of ref document: 20210604

Kind code of ref document: T

Free format text: AVAILABILITY OF NATIONAL TRANSLATION

Effective date: 20210531

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG9D

REG Reference to a national code

Ref country code: SK

Ref legal event code: T3

Ref document number: E 37520

Country of ref document: SK

REG Reference to a national code

Ref country code: HU

Ref legal event code: AG4A

Ref document number: E054669

Country of ref document: HU

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20210421

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210721

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2875355

Country of ref document: ES

Kind code of ref document: T3

Effective date: 20211110

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210821

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210722

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210721

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

REG Reference to a national code

Ref country code: AT

Ref legal event code: UEP

Ref document number: 1384905

Country of ref document: AT

Kind code of ref document: T

Effective date: 20210421

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602017036997

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: TR

Payment date: 20211014

Year of fee payment: 5

Ref country code: SK

Payment date: 20211015

Year of fee payment: 5

Ref country code: PT

Payment date: 20211018

Year of fee payment: 5

Ref country code: SE

Payment date: 20211013

Year of fee payment: 5

Ref country code: RO

Payment date: 20211015

Year of fee payment: 5

Ref country code: ES

Payment date: 20211102

Year of fee payment: 5

Ref country code: DE

Payment date: 20211014

Year of fee payment: 5

Ref country code: CZ

Payment date: 20211018

Year of fee payment: 5

Ref country code: GB

Payment date: 20211014

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: IT

Payment date: 20211019

Year of fee payment: 5

Ref country code: HU

Payment date: 20211122

Year of fee payment: 5

Ref country code: FR

Payment date: 20211014

Year of fee payment: 5

26N No opposition filed

Effective date: 20220124

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: PL

Payment date: 20211015

Year of fee payment: 5

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210821

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20211031

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20211004

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20211031

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20211031

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20211031

REG Reference to a national code

Ref country code: HU

Ref legal event code: HC9C

Owner name: AUTOMATION, PRESS AND TOOLING, A.P. & T AB, SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20211004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CZ

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 602017036997

Country of ref document: DE

REG Reference to a national code

Ref country code: SK

Ref legal event code: MM4A

Ref document number: E 37520

Country of ref document: SK

Effective date: 20221004

REG Reference to a national code

Ref country code: SE

Ref legal event code: EUG

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20221004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: RO

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

Ref country code: PT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230404

Ref country code: HU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221005

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221031

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20230503

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221005

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20231124

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 1384905

Country of ref document: AT

Kind code of ref document: T

Effective date: 20221004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221005

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221005

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20221004

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20210421