GB2624254A - Hydraulic systems - Google Patents

Hydraulic systems Download PDF

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Publication number
GB2624254A
GB2624254A GB2216981.7A GB202216981A GB2624254A GB 2624254 A GB2624254 A GB 2624254A GB 202216981 A GB202216981 A GB 202216981A GB 2624254 A GB2624254 A GB 2624254A
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United Kingdom
Prior art keywords
inlet
hydraulic
electric power
pressure
relieve
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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
GB2216981.7A
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GB202216981D0 (en
Inventor
Brian Dean Michael
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Individual
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Individual
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Priority to GB2216981.7A priority Critical patent/GB2624254A/en
Publication of GB202216981D0 publication Critical patent/GB202216981D0/en
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Pending legal-status Critical Current

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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
    • F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
    • F15B20/002—Electrical failure
    • E—FIXED CONSTRUCTIONS
    • E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
    • E05C—BOLTS OR FASTENING DEVICES FOR WINGS, SPECIALLY FOR DOORS OR WINDOWS
    • E05C19/00—Other devices specially designed for securing wings, e.g. with suction cups
    • 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
    • F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
    • F15B20/004—Fluid pressure supply failure
    • 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
    • F15B2211/20507—Type of prime mover
    • F15B2211/20515—Electric 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
    • F15B2211/20538—Type of pump constant capacity
    • 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
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/3056—Assemblies of multiple valves
    • F15B2211/30565—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
    • F15B2211/3058—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve having additional valves for interconnecting the fluid chambers of a double-acting actuator, e.g. for regeneration mode or for floating mode
    • 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
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3138—Directional control characterised by the positions of the valve element the positions being discrete
    • 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
    • F15B2211/30—Directional control
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/327—Directional control characterised by the type of actuation electrically or electronically
    • 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
    • F15B2211/40—Flow control
    • F15B2211/41—Flow control characterised by the positions of the valve element
    • F15B2211/411—Flow control characterised by the positions of the valve element the positions being discrete
    • 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
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41581—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a return line
    • 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
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/426—Flow control characterised by the type of actuation electrically or electronically
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/51—Pressure control characterised by the positions of the valve element
    • F15B2211/511—Pressure control characterised by the positions of the valve element the positions being discrete
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5157—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a return line
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5159—Pressure control characterised by the connections of the pressure control means in the circuit being connected to an output member and a return line
    • 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
    • F15B2211/50—Pressure control
    • F15B2211/52—Pressure control characterised by the type of actuation
    • F15B2211/526—Pressure control characterised by the type of actuation electrically or electronically
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/86—Control during or prevention of abnormal conditions
    • F15B2211/862—Control during or prevention of abnormal conditions the abnormal condition being electric or electronic failure
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/86—Control during or prevention of abnormal conditions
    • F15B2211/862—Control during or prevention of abnormal conditions the abnormal condition being electric or electronic failure
    • F15B2211/8623—Electric supply failure
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/86—Control during or prevention of abnormal conditions
    • F15B2211/863—Control during or prevention of abnormal conditions the abnormal condition being a hydraulic or pneumatic failure
    • F15B2211/8636—Circuit failure, e.g. valve or hose failure
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/865—Prevention of failures
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/875—Control measures for coping with failures
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/875—Control measures for coping with failures
    • F15B2211/8757—Control measures for coping with failures using redundant components or assemblies

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

A hydraulic circuit10 for a hydraulic system is provided. The hydraulic circuit 10 comprises: a hydraulic motor 12 (e.g. a hydraulic cylinder); an electric power supply inlet 14; pressurising means 16, 18 operable by electric power from inlet 14 to pressurise hydraulic fluid to operate hydraulic motor 12; and relief means 22 biased by biasing means 24 to an open condition to relieve pressure of the hydraulic fluid in the absence of power at inlet 14. The relief means 22 is held in a closed condition while there is power at inlet 14 so as to allow or not to relieve the pressure. Pressurising means 16, 18 comprises an electric motor 16 powering a hydraulic pump 18. Relief means 22 comprises (e.g. electromagnetic) means 20 connected to outlet 14 to hold the relief means 22 in the closed condition. The motor's load 26 may be car park gates, normally closed but able to damage the hydraulic circuit 10 if opened by hand during a power outage if the pressure remains.

Description

HYDRAULIC SYSTEMS
FIELD OF THE INVENTION. This invention relates to hydraulic circuits.
BACKGROUND. A hydraulic circuit may comprise a hydraulic motor and electric means operable by electric power to pressurise hydraulic fluid in the circuit to operate the hydraulic motor to move a load. The arrangement may be such that during an outage of the electric power to the electric means the load will be maintained in its current position. Any attempt to move the load during the outage may cause damage, e.g. to the hydraulic motor. The load, for example, may be a security gate, which is normally in a closed and/or secured position, except that it is arranged to be opened by the motor in response to appropriate signals to the hydraulic circuit (when passage through the gate is required) and thereafter re-closed by the motor.
TETE INVENTION.
It may be desirable that in the event of an outage (which term includes e.g. a power failure and e.g. a reduction of e.g. voltage below a value sufficient to operate the hydraulic circuit) while the gate is closed it is required to be put into an open position, e.g. for emergency use. One solution considered by the inventor is to provide battery-power backup and arrange that upon occurrence of the outage the battery backup will operate the electric means to operate the motor to move the gate to an open position (and preferably leave it there, e.g. until the electric power has been restored, i.e. until the outage has been terminated). Disadvantages are the cost and bulk of a suitable battery backup and its relatively short life even if it is rechargeable. Another solution considered by the inventor is to provide spring or other potential-energy means kept in check during normal power supply, e.g. by electromagnetic means, but released upon the outage to move the gate to an open position. Disadvantages are the cost and bulk of suitable potential-energy means and also the difficulty of restoring the same to its pre-outage condition after the outage.
The inventor considers that a much neater, simpler and otherwise more advantageous system is to provide the hydraulic circuit with means to relieve a hydraulic fluid pressure in the absence of power. By this means, the load can be moved (e.g. opening of the gates) other than by the motor (e.g. by hand) during an outage without damage to the system. Such means might be a maglockcontrolled (or similar) relief valve arranged to be held closed by the maglock (to allow the normal pressurisation needed for operation of the motor) in the presence of power and released by the bias of the maglock upon the outage to relieve the pressurisation. By this means, a load, e.g. a gate, normally movable by the motor can be moved, e.g. by hand, during the loss of electric power without causing (e.g. due to back-pressure) hydraulic fluid in the circuit to cause damage, e.g. to the hydraulic motor and/or valves. Upon resumption of power after the outage, the maglock will again close the relief valve, so that the usual pressurisation can be effective to operate the motor in accordance with any settings or responses of the hydraulic system. Also, compared with the aforesaid solutions, the saving in costs and/or materials (e.g. batteries requiring to be renewed or any requirement to use costly and bulky potential-energy means) makes this invention particularly environmentally beneficial.
One aspect of the invention consists in relief means arranged to relieve pressure of a hydraulic 40 fluid during an outage of electric power at an electric power inlet.
Another aspect of the invention consists in a hydraulic motor with relief means that have an electric power inlet and that are arranged to relieve pressure of a hydraulic fluid (to operate the motor) in the absence of (appropriate) electric power at the inlet or otherwise during an outage at the inlet.
Embodiments of the invention can have any of the following features: the relief means is arranged not to relieve the said pressure while electric power is present at said inlet; the relief means is biased to relieve pressure as aforesaid and arranged to be held against such bias during appropriate electric power at the inlet so as not to relieve as aforesaid.
Another aspect of the invention consists in a hydraulic system comprising: a hydraulic motor (which may be simply a hydraulic cylinder), an electric power supply inlet, pressurising means operable by electric power from the inlet to pressurise hydraulic fluid and 10 arranged to supply the pressurised hydraulic fluid to operate the hydraulic motor, and relief means connected to control the pressure of the hydraulic fluid and having what may be termed an open condition and a closed condition, constructed and arranged for its open condition to relieve the pressure of the hydraulic fluid and for its closed condition to allow, or not relieve, hydraulic pressure of the hydraulic fluid to operate the hydraulic motor, constructed and arranged to be held in its said closed condition when power is available from the inlet, and biased to be in its said open condition while there is an outage of electric power from the inlet.
Embodiments of the invention can have any one or more of the following features: comprising electromagnetic means connected between said inlet and said relief means, constructed and arranged to hold the latter in its said closed condition when power is available from the inlet; in which the relief means comprise valve means; in which the aforesaid bias is provided by resilient (e.g. spring or flexure) means; in which the pressurising means comprise a hydraulic pump constructed and arranged to pressurise the fluid and electric means (e.g. an electric motor) connected to said inlet and said pump and constructed and arranged to operate the pump under electric power from said inlet.
Another aspect of the invention provides a hydraulic system comprising: a hydraulic motor; an electric power supply inlet; pressurising means operable by electric power from the inlet to pressurise hydraulic fluid to operate the hydraulic motor; and relief means biased to an open condition to relieve a pressure of the hydraulic fluid while there is an outage of power at the inlet and held in a closed condition while there is power at the inlet so as to allow or not to relieve the pressure.
Another aspect of the invention provides a hydraulic system comprising a hydraulic motor and an electric power inlet, the system being such that an operation of the system requires electric power from the inlet, and comprising pressure relief means having a first condition and a second condition and being biased to the first condition, and being connected to allow or enable the said operation in the second condition and to be able to relieve a pressure in the system in the first condition, and being connected to the inlet to be held in the second condition while there is electric power at the inlet.
PARTICULAR DESCRIPTION.
Reference will now be made by way of example to the accompanying drawings, in which: Figure 1 is a schematic diagram of a hydraulic system embodying the invention, as applied to the 5 security gate of a car park; and Figure 2 is a schematic diagram of a hydraulic motor with relief means embodying the invention, which may be sold alone or be part of (or part of it may be part of) the Figure 1 embodiment in place of or in addition to corresponding elements in the Figure 1 embodiment.
Referring to the drawings, identical references refer to the same item in the same Figure or 10 different Figures or items that are identical or similar or have similar functions, and references with the same first two digits refer to items that are identical or similar or have similar or related] functions.
A hydraulic system 10 comprises a hydraulic motor 12 which is simply a hydraulic cylinder 12, an electric power supply inlet 14, pressurising means 16, 18 operable by electric power from the inlet 14 to pressurise hydraulic fluid and arranged to supply the pressurised hydraulic fluid to operate the hydraulic motor 12 and relief means 20, 22, 24 connected to control the pressure of the hydraulic fluid and having what may be termed an open condition and a closed condition. The relief means 20, 22, 24 is constructed and arranged for its open condition to relieve the pressure of the hydraulic fluid and for its closed condition to allow (or not relieve) hydraulic pressure of the hydraulic fluid to operate the hydraulic motor 12. It is also constructed and arranged to be held in its said closed condition when power is available from the inlet 14; and it is biased to be in its said open condition while there is an outage of electric power from the inlet 14.
The relief means 20, 22, 24 comprise valve means 22 in which the aforesaid bias is provided by resilient (e.g. spring or flexure) means 24, and electromagnetic means 20 connected between valve 25 means 22 and inlet 14 and constructed and arranged to hold the valve means 22 in its said closed condition when power is available from the inlet 14.
The pressurising means 16, 18 comprise a hydraulic pump 18 constructed and arranged to pressurise the fluid, and electric means 16 (e.g. an electric motor) connected to said inlet 14 and said pump 18 and constructed and arranged to operate the pump 18 under electric power from said inlet 14.
In the system 10, a load 26 (e.g. car park gates) is operated (e.g. opened and closed) by hydraulic motor 12 under the guidance of an operating valve arrangement 28, itself under the control of control means 30, which may comprise various sensors, fobs, cards and keys (not shown individually) The arrangement including hydraulic motor 12 and operating valve arrangement 28 normally holds the load 26 in any position to which it has been moved by hydraulic motor 12 until there is a change of control signals from a first control means 30.
If there is an outage of power (e.g. a power failure) at inlet 14, electromagnetic means 20 is no longer powered and releases valve means 22 to its said open condition under the urge of its bias means 24, which allows the pressure of the pressurised hydraulic fluid to fall. Maglock 34 is therefore also no longer powered. If, in this open condition of valve means 22, the gates of load 26 are forcibly opened by hand, e.g. for an emergency situation, there is little or no resistance due to hydraulic fluid in the part of the hydraulic circuit embracing hydraulic motor 12 and control valve arrangement 28, so that this part of the circuit is not thereby damaged.
Electric motor 16 draws its power from inlet 14 via a second control means 32, which may be simply an on-off switch or may comprise also timing means possibly connected to a maglock 34 being part of gates 26 (and powered from inlet 14) to hold them closed, e.g. at night time, when electric motor 16 is switched off. Second control means 32 may be considered as being on a higher administrative level than the normal (e.g. daytime) running, and may be partly arbitrary (e.g. set from time to time by an administrator) and partly preset (programmed, e.g. to distinguish daytime and night-time operation of the system 10).
The system also comprises the usual reservoir 36 and over-pressure relief valve 38. When valve means 22 is in its said open condition, hydraulic fluid can bleed along the path 40 shown in 10 dashed-line arrows and back to reservoir 36.
In the Figure 1 embodiment, the relief means 20, 22, 24, when in relief mode (i.e. said first or open condition), bleeds hydraulic fluid back to reservoir 36. In the Figure 2 embodiment, the relief means 20, 22, 24, when in relief mode, allows hydraulic fluid to bleed from compartment 121 to compartment 122 of hydraulic motor cylinder 12 and vice versa under the artificially increased pressure in one of these compartments 121, 122 that may occur if load (e.g. gates) 26 is moved by hand during the absence of power at inlet 14.
With the Figure 2 embodiment, there may not be bleeding back to a reservoir 36. Also, electric power inlet may be simply suitable terminals 14 from which electromagnetic means 20 can receive operating power. It may be that there are different pressures in the hydraulic fluid in different parts of the hydraulic system and the relief means serves to relieve one of these pressures, e.g. that might cause damage, e.g. within the hydraulic motor 12, It will be seen that there has been provided a hydraulic system 10 which comprises: a hydraulic motor 12, e.g. a hydraulic cylinder; an electric power supply inlet 14; pressurising means 16, 18 operable by electric power from inlet 14 to pressurise hydraulic fluid to operate hydraulic motor 12; and relief means 20, 22, 24 biased to an open condition to relieve pressure of the hydraulic fluid in the absence of power at inlet 14 and held in a closed condition while there is power at inlet 14 so as to allow or not to relieve the pressure. Pressurising means 16, 18 comprises an electric motor 16 powering a hydraulic pump 18. Relief means 20, 22, 24 comprises (e.g. electromagnetic) means 20 connected to outlet 14 to hold the relief means in said dosed condition. The motor's load 26 may be car park gates, normally closed but able to damage the hydraulic system 10 if opened by hand during a power outage if the pressure remains.it will be apparent to one skilled in the art, that features of the different embodiments disclosed herein may be omitted, selected, combined or exchanged and the invention is considered to extend to any new and inventive combination thus formed, taking into account the following. Where a preference or particularisation is stated, there is implied the possibility of its negative, i.e. a case in which that preference or particularisation is absent.
Many variations of the invention and embodiments hereinbefore described will be apparent to people skilled in the art and all such variations are to be considered as falling within the scope of the invention.

Claims (12)

  1. CLAIMS1. Relief means for a hydraulic circuit arranged to relieve pressure of a hydraulic fluid in the absence of electric power at an electric power inlet.
  2. 2. A hydraulic motor with relief means that have an electric power inlet and that are arranged to relieve pressure of a hydraulic fluid during an outage at the inlet.
  3. 3. The invention of any preceding claim, in which the relief means is arranged not to relieve the said pressure while electric power is present at said inlet.
  4. 4. The invention of any preceding claim, in which the relief means is biased to relieve pressure as aforesaid and arranged to be held against such bias during appropriate electric power at the inlet so as not to relieve as aforesaid.
  5. 5. A hydraulic system comprising: a. a hydraulic motor, b. an electric power supply inlet, c. pressurising means operable by electric power from the inlet to pressurise hydraulic fluid and arranged to supply the pressurised hydraulic fluid to operate the hydraulic motor, d. and relief means connected to control the pressure of the hydraulic fluid and having what may be termed an open condition and a closed condition, constructed and arranged for its open condition to relieve the pressure of the hydraulic fluid and for its closed condition to allow, or not relieve, hydraulic pressure of the hydraulic fluid to operate the hydraulic motor, ii. constructed and arranged to be held in its said closed condition when power is available from the inlet, and biased to be in its said open condition while there is an outage of electric power from the inlet.
  6. 6. A system as claimed in claim 5, in which the relief means comprise electromagnetic means connected to said inlet and constructed and arranged to hold the latter in its said closed condition when power is available from the inlet.
  7. 7. A system as claimed in claim 5 or 6, in which the relief means comprise valve means.
  8. 8. A system as claimed in any one of claims 5 to 7, in which the aforesaid bias is provided by resilient means.
  9. 9. A system as claimed in any one of claims 5 to 8, in which the pressurising means comprise a hydraulic pump constructed and arranged to pressurise the fluid, and electric means connected to said inlet and said pump and constructed and arranged to operate the pump under electric power from said inlet.
  10. 10. A system as claimed in any one of claims 5 to 9, in which the hydraulic motor is a hydraulic cylinder.
  11. 11. A hydraulic system comprising: a hydraulic motor; an electric power supply inlet; pressurising means operable by electric power from the inlet to pressurise hydraulic fluid to operate the hydraulic motor; and relief means biased to an open condition to relieve a pressure of the hydraulic fluid while there is an outage of power at the inlet and held in a closed condition while there is power at the inlet so as to allow or not to relieve the pressure.
  12. 12. A hydraulic system comprising a hydraulic motor and an electric power inlet, the system being such that an operation of the system requires electric power from the inlet, and comprising pressure relief means having a first condition and a second condition and being biased to the first condition, and being connected to allow or enable the said operation in the second condition and to be able to relieve a pressure in the system in the first condition, and being connected to the inlet to be held in the second condition while there is electric power at the
GB2216981.7A 2022-11-14 2022-11-14 Hydraulic systems Pending GB2624254A (en)

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Application Number Priority Date Filing Date Title
GB2216981.7A GB2624254A (en) 2022-11-14 2022-11-14 Hydraulic systems

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Application Number Priority Date Filing Date Title
GB2216981.7A GB2624254A (en) 2022-11-14 2022-11-14 Hydraulic systems

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GB202216981D0 GB202216981D0 (en) 2022-12-28
GB2624254A true GB2624254A (en) 2024-05-15

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3943824A (en) * 1975-01-22 1976-03-16 Deere & Company Hydraulic system
GB2330869A (en) * 1997-09-11 1999-05-05 Stabilus Gmbh Movable member : fluid-pressure mover : pressure control
EP3693616A1 (en) * 2019-02-11 2020-08-12 Goodrich Actuation Systems SAS Actuator control valve arrangement
US20210348696A1 (en) * 2020-05-09 2021-11-11 Emerson Process Management Valve Automation, Inc. Universal Logic Circuit for Electro-Hydraulic Actuator

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3943824A (en) * 1975-01-22 1976-03-16 Deere & Company Hydraulic system
GB2330869A (en) * 1997-09-11 1999-05-05 Stabilus Gmbh Movable member : fluid-pressure mover : pressure control
EP3693616A1 (en) * 2019-02-11 2020-08-12 Goodrich Actuation Systems SAS Actuator control valve arrangement
US20210348696A1 (en) * 2020-05-09 2021-11-11 Emerson Process Management Valve Automation, Inc. Universal Logic Circuit for Electro-Hydraulic Actuator

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