US3703851A - Hydraulic actuator - Google Patents

Hydraulic actuator Download PDF

Info

Publication number
US3703851A
US3703851A US101089A US3703851DA US3703851A US 3703851 A US3703851 A US 3703851A US 101089 A US101089 A US 101089A US 3703851D A US3703851D A US 3703851DA US 3703851 A US3703851 A US 3703851A
Authority
US
United States
Prior art keywords
pistons
piston
cylinders
actuator
jack
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.)
Expired - Lifetime
Application number
US101089A
Other languages
English (en)
Inventor
Richard Joseph Ifield
William Robert Ifield
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Application granted granted Critical
Publication of US3703851A publication Critical patent/US3703851A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/02—Mechanical layout characterised by the means for converting the movement of the fluid-actuated element into movement of the finally-operated member
    • F15B15/06—Mechanical layout characterised by the means for converting the movement of the fluid-actuated element into movement of the finally-operated member for mechanically converting rectilinear movement into non- rectilinear movement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B9/00—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts, not specific to groups F01B1/00 - F01B7/00
    • F01B9/04—Reciprocating-piston machines or engines characterised by connections between pistons and main shafts, not specific to groups F01B1/00 - F01B7/00 with rotary main shaft other than crankshaft
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/18—Mechanical movements
    • Y10T74/1856—Reciprocating or oscillating to intermittent unidirectional motion

Definitions

  • PATENTS Means are provided to alternately switch from one 2 979 034 4/1961 Gey 92/33 X' cylinder to the other' er 3,414,693 12/1968 Watson et al ..92/5 X 5 Claim, 5 Drawing Figures PATENTED 28 I97? 3 7 O3 8 51 SHEET 2 OF 4 PAIENTED nuv 28 m2 SNEEI 3 0F 4 HYDRAULIC ACTUATOR This invention relates to actuators for the movement of substantial loads through substantial distances.
  • Actuators of the kind to which the invention relates may be used, for example, for the lifting or hauling of heavy loads, the straining of pre-stressing cables in concrete structures, the rotation of machine elements against the effects of heavy restraining torques and the like.
  • An object of the present is to provide an actuator of the kind under discussion which is relatively simple in construction and,,therefore, inexpensive to manufacture.
  • the invention achieves that object by the provision of two hydraulic jack cylinders which work in concert and which are effective to move a load in increments with one jack cylinder taking over from the other at the end of each increment to provide substantially continuous motion.
  • the invention consists in an actuator comprising a body structure defining two jack cylinders and ducts for the supply of pressurized hydraulic fluid to, and exhaust of fluid from, said jack cylinders, two pistons disposed one in each cylinder, changeover valve means controlling the admission and exhaust of fluid to and from said cylinders in a manner causing said pistons to reciprocate through power and return strokes with the power stroke of one piston alternating with that of the other and with substantially no time delay between successive power strokes, and power transmission means which drive-connect each said piston to a load to be moved during the pistons power stroke but release each piston from the load during the piston s return stroke.
  • the power transmission means comprises a helicoidal elements, such as a nut or a worm which engages a co-acting loaded element, such as a threaded shaft or a worm-wheel, together with means to rotate the helicoidal element during the return stroke of its associated piston to permit the helicoidal element to move translationally relative to the loaded element.
  • a helicoidal elements such as a nut or a worm which engages a co-acting loaded element, such as a threaded shaft or a worm-wheel, together with means to rotate the helicoidal element during the return stroke of its associated piston to permit the helicoidal element to move translationally relative to the loaded element.
  • the helicoidal element is not rotated and, thus, translational movement imparted to it by its associated piston causes the required motion of the loaded element, which is thereby transmitted to the load to be moved.
  • the invention is applicable to the rotation of a load in either direction in a controlled and irreversible manner.
  • it may be incorporated in the drive for slewing a large crane, turning a winch drum or similar application. It is also applicable to providing a continuous linear motion on a long shaft.
  • F IG. 1 shows, in front elevation and partly in section, an actuator adapted for rotary motion
  • FIG. 2 shows, in end elevation and partly in section, a view along the line 2-2 of FIG. 1,
  • FIG. 3 shows, in front elevation and partly in section, an actuator adapted for translational motion
  • FIG. 4 shows, in elevation, a view along the line 4-4 of FIG. 3.
  • the drive transmission means include a loaded element that is to say an element which carries or is connected to the load to be moved in the form of a worm-wheel 5 mounted for rotation about an axis 6 which is fixed relatively to the body structure 7 of the actuator.
  • the body structure 7 enclosing the worm wheel contains pairs of jack cylinders such as 8 and 9 with closed ends and having their axes tangential to and in the same plane as the worm wheel 5.
  • pairs of jack cylinders such as 8 and 9 with closed ends and having their axes tangential to and in the same plane as the worm wheel 5.
  • any greater number of pairs may be employed to increase the driving torque for a given maximum worm tooth loading, the number being limited only by the available peripheral space around the worm wheel.
  • a respective pair of jack pistons 10 and l 1 is slidably mounted in jack cylinders 8 and 9.
  • the jack pistons have a sealed piston head at each end sliding in the jack cylinders.
  • the center portion of the jack pistons is of helicoidal form as a worm l2 engaging the teeth of the worm wheel 5.
  • the worm has a single start and is irreversible.
  • Each pair of jack pistons has a slidable drive connection such as 13 passing through a seal such as 14 in the end wall of cylinder 9, to provide means for rotating the worm 12 on its unloaded return stroke.
  • the pair of jack cylinders 8 and 9 and its associated jack, drive shaft and other associated components will be referred to as the first and the other pair of jack cylinders and its associated jack, drive shaft and other associated components enclosed within the housing 15 will be referred to as the second components as named.
  • the body structure 7 also defines ducts for the supply of pressurized fluid to and the exhaust of fluid from the closed ends of the cylinders.
  • One end of the second pair of cylinders has a duct B.
  • the adjacent end of the first pair of cylinders has a duct C.
  • the opposite ends of the pairs of cylinders are adjacent to one another and are interconnected with a common duct A.
  • duct B is at high pressure continuously and duct C is at low pressure continuously. These pressures are reversed for the opposite direction of drive.
  • Duct A is connected to any suitable automatic valve (see FIG. 5), oscillating to pressurize and exhaust the duct.
  • the automatic valve may be an electric solenoid operated valve responsive to the triggering of the double acting micro switch 16 operated by the lost motion stop rod 17 at each end of the stroke of piston 10, or it may be any other form of snap action valve, triggered at each end of the piston stroke.
  • the micro switches or other triggering devices are required at only one pair of .pistons, in this case the first pair. Because the automatic valve is triggered at each end of the stroke of the first pair of pistons some excess movement may be allowed at these pistons to ensure triggering of the valve before the piston reaches the limits of its movements.
  • the switching mechanism for the automatic valve is associated only with the first pair of pistons, this pair of pistons will always operate over the full stroke.
  • the stroke of the second pair of pistons will depend on the speed of the return stroke of the first pair of pistons, which must trigger the automatic valve before the second pair of pistons reach the limit of the power stroke.
  • a single motor may drive the two pairs of pistons through differential gearing (not shown).
  • the worm drive is irreversible, the worm wheel is held against rotation when the power is shut off.
  • one of the two piston rotating motors may be reversed, without reversing the other, or the automatic valve may be prevented from operating. In either case the two pairs of pistons would then move to their adjacent stops, which prevents movement in either direction of rotation of the worm wheel.
  • FIG. 5 shows a separate pump to power the small motors 18 shown on FIG. 1, these have a common inlet duct and a common delivery duct, which are reversible for the opposite direction of rotation and are identified by the letters D and E.
  • FIG. 5 shows diagrammatically a main variable displacement power supply pump 33, the output of which determines the rotational speed of the actuator.
  • a small fixed displacement pump 34 is shown to rotate the motors 18 during the unloaded return strokes of the pistons; the output of this pump must be adequate to return the pistons fully on their return strokes for the highest actuator speed and the excess flow from the pump is discharged through the relief valve 35.
  • a relief valve 36 is also shown to prevent overload at the .main pump 33.
  • Two manually operated reversing valves 37 and 38 are shown to reverse the high and low pressures to ducts B and C and to reverse the direction of rotation of the small motors 18, FIG. 1 when it is required to reverse the direction of rotation of the actuator.
  • the automatic valve previously referred to is shown at 39 as a solenoid operated valve, the previously being energized in response to the movements of the rpeviously described microswitch 16, at each end of the stroke of the worm 12.
  • the movements of this automatic valve cause the duct A to alternate between the pressure supply from the pump 33 and the discharge to the reservoir 40.
  • a linear actuator is provided, as shown in FIGS. 3 and 4.
  • the two jack pistons may be in the form of nuts 19 and 20 on a threaded shaft 21, being the helicoidal member to which the load to be moved is connected.
  • the body structure 22 surrounds the threaded shaft which extends co-axially through the two jack cylinders 23 and 24.
  • the jack cylinders may be opposite end portions of a single cylindrical cavity and both jack pistons may have respective axially extending skirts 25 and 26 thereon which project through sealing glands at the outer ends of the cylindrical cavity.
  • the jack pistons may have inwardly direct skirts thereon, slidable telescopically within the housing 22, and each having respective annular fluid seals 28 and 29 to prevent leakage of fluid from the cylinders to the screw-threaded shaft.
  • Each jack piston may have a respective spur gear 30 and 31 fixed to its outwardly projecting skirt outside the jack cylinder space and said spur gears may mesh respectively with pinions such as 32 driven by return motors as described in the first embodiment of the invention.
  • duct A leads to the space between the two pistons
  • duct B leads to one closed end of the cylinder
  • Duet C leads to the other closed end of the cylinder.
  • the double acting micro switch 27 or other triggering mechanism (see FIG. 5) for the automatic valve may be operated at the ends of the strokes of the first piston as previously described in the first example of the invention.
  • the two return motors may be replaced by a single motor, rotating the two pistons on their return strokes, through differential gearing.
  • Duct A is at high pressure when the pistons are closest together and at low pressure when the pistons are furthest apart.
  • duct A When duct A is at high pressure, the opposite face of the first piston is at low pressure and the piston thrusts the screwed shaft axially; the opposite face of the second piston is at high pressure, so there is no pressure difference and the piston is rotated, screwing along the shaft against the stop, until the first piston triggers the switch.
  • Duct A now changes to low pressure, causing the second piston to thrust on the shaft and allowing the first piston to rotate, screwing along the shaft until if triggers the switch to repeat the cycle of operation.
  • a hydraulic actuator comprising a body structure defining two jack cylinders and ducts for the supply of pressurized hydraulic fluid to, and exhaust of fluid from, said jack cylinders, tow pistons disposed one in each cylinder, each having a helicoidal portion in the form of a screw thread co-acting with a mating portion of an actuator, changeover valve means controlling the admission and exhaust of fluid to and from said cylinders in a manner causing said pistons to reciprocate through power and return strokes with the power stroke of one piston alternating with that of the other and with substantially no time delay between successive power strokes, and means to rotate a selective piston to enable it to move back to its staring position while the other piston drives said mating portion.
  • an automatic valve responsive to triggering by path limit detecting means at each end of the stroke of one of said pistons is adapted to pressurize and exhaust said ducts successively with an oscillatory action, whereby no pressure difference exists at one pair of said pistons while one of another pair of said pistons is thrust axially to rotate said mating portion, or to move a linear actuator axially relative to a screwed shaft.
  • a hydraulic actuator comprising:
  • a body structure defining two jack cylinders and ducts for the supply and exhaust of pressurized fluid to and from said cylinders, b. two pistons disposed one in each cylinder, each

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Transmission Devices (AREA)
  • Actuator (AREA)
  • Fluid-Driven Valves (AREA)
US101089A 1970-01-06 1970-12-23 Hydraulic actuator Expired - Lifetime US3703851A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AU1870 1970-01-06

Publications (1)

Publication Number Publication Date
US3703851A true US3703851A (en) 1972-11-28

Family

ID=3690913

Family Applications (1)

Application Number Title Priority Date Filing Date
US101089A Expired - Lifetime US3703851A (en) 1970-01-06 1970-12-23 Hydraulic actuator

Country Status (7)

Country Link
US (1) US3703851A (enrdf_load_stackoverflow)
JP (1) JPS5138876B1 (enrdf_load_stackoverflow)
CA (1) CA925406A (enrdf_load_stackoverflow)
DE (1) DE2100055C3 (enrdf_load_stackoverflow)
FR (1) FR2075948B1 (enrdf_load_stackoverflow)
GB (1) GB1312369A (enrdf_load_stackoverflow)
SE (1) SE378289B (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4342257A (en) * 1980-04-28 1982-08-03 Weyer Paul P Rotary actuator with integral fluid coupling joint
WO2020002732A1 (es) * 2018-06-27 2020-01-02 Ramon Vicente Berenguer Mecanismo hidráulico y metodo para produccion de energia

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2539459A1 (fr) * 1983-01-13 1984-07-20 Durand Francois Moteur hydraulique lent
JPS60163167U (ja) * 1985-01-30 1985-10-30 ダスキンフランチヤイズ株式会社 棚付運搬車
JPS638157U (enrdf_load_stackoverflow) * 1986-07-03 1988-01-20
CN117167362B (zh) * 2023-10-19 2024-02-23 常州斯曼特电器有限公司 一种用于油缸活塞杆的位置检测系统

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2808033A (en) * 1955-07-27 1957-10-01 Hydro Torque Inc Torque unit
US2970574A (en) * 1959-04-14 1961-02-07 Gen Motors Corp Dual piston hydraulic centering actuator
US2979034A (en) * 1959-02-18 1961-04-11 Gen Motors Corp Hydraulic actuator with load proportional locking means
US3000357A (en) * 1958-12-19 1961-09-19 Gen Motors Corp High temperature hydraulic actuator assembly
US3179015A (en) * 1963-02-11 1965-04-20 Ingersoll Rand Co Control for rock drill mounting
US3187592A (en) * 1962-03-14 1965-06-08 Gen Motors Corp Rotary actuator
US3414693A (en) * 1966-04-29 1968-12-03 Tomkins Johnson Co Cylinder head limit switch assembly

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3090360A (en) * 1961-09-08 1963-05-21 King Of Prussia Res & Dev Corp Hydraulic actuator

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2808033A (en) * 1955-07-27 1957-10-01 Hydro Torque Inc Torque unit
US3000357A (en) * 1958-12-19 1961-09-19 Gen Motors Corp High temperature hydraulic actuator assembly
US2979034A (en) * 1959-02-18 1961-04-11 Gen Motors Corp Hydraulic actuator with load proportional locking means
US2970574A (en) * 1959-04-14 1961-02-07 Gen Motors Corp Dual piston hydraulic centering actuator
US3187592A (en) * 1962-03-14 1965-06-08 Gen Motors Corp Rotary actuator
US3179015A (en) * 1963-02-11 1965-04-20 Ingersoll Rand Co Control for rock drill mounting
US3414693A (en) * 1966-04-29 1968-12-03 Tomkins Johnson Co Cylinder head limit switch assembly

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4342257A (en) * 1980-04-28 1982-08-03 Weyer Paul P Rotary actuator with integral fluid coupling joint
WO2020002732A1 (es) * 2018-06-27 2020-01-02 Ramon Vicente Berenguer Mecanismo hidráulico y metodo para produccion de energia
ES2736574A1 (es) * 2018-06-27 2020-01-02 Vicente Berenguer Ramon Mecanismo hidraulico y metodo para produccion de energia

Also Published As

Publication number Publication date
FR2075948B1 (enrdf_load_stackoverflow) 1975-02-21
CA925406A (en) 1973-05-01
DE2100055B2 (de) 1978-11-23
JPS5138876B1 (enrdf_load_stackoverflow) 1976-10-25
SE378289B (enrdf_load_stackoverflow) 1975-08-25
GB1312369A (en) 1973-04-04
DE2100055A1 (de) 1971-07-15
DE2100055C3 (de) 1979-07-26
FR2075948A1 (enrdf_load_stackoverflow) 1971-10-15

Similar Documents

Publication Publication Date Title
US3338140A (en) Actuator
US3828400A (en) Hydraulic motors and the like
US3080852A (en) Variable stroke actuator
US3444784A (en) Fluid motor rotary actuator
US3778198A (en) Meshing rotary piston machine with an internal shaft
US3703851A (en) Hydraulic actuator
US3733914A (en) Motion conversion means
US3267817A (en) Fluid rotary actuator
US3732783A (en) Fluid cylinder having self-locking means
US3979999A (en) Fluid cylinder having self-locking means
USRE29000E (en) Hydraulic actuator
US3930415A (en) Motion converter
US2919682A (en) Linear fluid actuator
US3862587A (en) Hydraulic motor
US3776100A (en) Cushion device
CN113309756A (zh) 一种基于内齿轮轴传动的低速大扭矩液压马达系统
US3339460A (en) Pressure fluid motor
US3656405A (en) Pressurized medium motor
US3581626A (en) Adjustable admission valve means for steam engines and the like
US3675539A (en) Hydraulic motor
US3878768A (en) Hydrostatic transmission
US4044654A (en) Hydraulic engine
US3103173A (en) Variable volume pumping apparatus
US3302528A (en) Twin compression chamber motor
RU2078256C1 (ru) Шаговый гидро(пневмо)двигатель