EP0386598A1 - Druckmittelbetriebener Drehkolben - Google Patents

Druckmittelbetriebener Drehkolben Download PDF

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Publication number
EP0386598A1
EP0386598A1 EP90103845A EP90103845A EP0386598A1 EP 0386598 A1 EP0386598 A1 EP 0386598A1 EP 90103845 A EP90103845 A EP 90103845A EP 90103845 A EP90103845 A EP 90103845A EP 0386598 A1 EP0386598 A1 EP 0386598A1
Authority
EP
European Patent Office
Prior art keywords
chamber
fact
rotary actuator
power
transmission member
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.)
Withdrawn
Application number
EP90103845A
Other languages
English (en)
French (fr)
Inventor
Luciano Migliori
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.)
Univer SpA
Original Assignee
Univer SpA
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 Univer SpA filed Critical Univer SpA
Publication of EP0386598A1 publication Critical patent/EP0386598A1/de
Withdrawn legal-status Critical Current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
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/12—Characterised by the construction of the motor unit of the oscillating-vane or curved-cylinder type
    • 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
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/082—Characterised by the construction of the motor unit the motor being of the slotted cylinder type

Definitions

  • This invention relates to a rotary actuator, operated by a pressure fluid, in particular compressed air, and concerns more exactly an actuating cylinder of circular shape that can provide a driving torque.
  • actuators From "Fluid Power Handbook & Directory", 1986/87, many rotary actuators are known. Most of these actuators comprise one or two linear cylinders having opposing pistons whose linear movement is converted into the rotary movement of an output shaft by means of a helical system, linking systems, racks, or drive chains operatively connected to the cylinder piston or pistons. These actuators are complex and bulky in design. In addition, they are appreciably limited in terms of angular speed and of output torque values. Furthermore, there are considerable frictional forces between the moving parts and in certain cases this reduces the actuator efficiency to as little as 30%.
  • rotary actuators comprising a revolving rotor in a cylindrical chamber, comprising one or two fins oppositely disposed in respect to a central output shaft.
  • a narrow seal must be provided both along the outside edges of the fins, which come into contact with the cylindrical wall of the chamber, and in correspondence with the central output shaft.
  • This second type of actuator has very low rotational speed in order to avoid the rapid deterioration of the sealing arising from any excessive pressure or speed.
  • the power and torque transmitted are relatively modest, or can be increased only by increasing the bulk and size of the actuator. With most of these actuators, too, it is essential to prevent axial thrust of the load or decentralised thrust. Such thrust could give rise to excessive friction on moving parts and especially on the sealing.
  • rodless pneumatic cylinders are also known. These comprise a linear chamber containing a reciprocating piston which is rigidly connected to an external power-transmission member through a longitudinal slit in the cylinder chamber, said slit being normally sealingly closed by a flexible strip inside the chamber.
  • This type off cylinder can only provide linear movement and has never been recommended or considered suitable for use as a rotary actuator because of the difficulties in adapting its structure to a circular shape which was sufficiently leak-proof for the fluid and which could guarantee an output torque that did not negatively affect the drive piston. Indeed, with regard both to the position of the slit and matching seal and to the type of connection between piston and external power-­transmission member, specialists were drawn towards other, strictly traditional solutions.
  • the object of this invention is to provide a fluid operated circular actuator in particular by compressed air, which applies the teachings of linear rodless cylinders, and by means of which it is possible to avoid the drawbacks of traditional circular actuators providing an actuator of comparatively reduced dimensions.
  • Another object of this invention is to provide a rotary actuator, as defined, by means of which it is possible to appreciably reduce problems of wear even at high working speeds.
  • a further object of this invention is to provide a rotary actuator, as described above, which, for the same size bulk can provide greater driving torque and power than that obtainable from known types of rotary actuators.
  • the actuator comprises a mainly circular body, indicated in its entirety by reference number 10, formed from two half-casings or shells 10a and 10b which together define an annular chamber 11 of circular cross-section or toroidal shape, inside which a piston 12 reciprocates, the external contours of said piston forming a fit with the toroidal contour of the actuator's chamber 11.
  • Reference number 13 indicates a partition member inside the chamber 11 provided with appropriate peripheral seals 14. The partition member 13 is positioned in correspondence to passages 15 and 16 for the inlet and outlet of a pressure fluid, for example compressed air.
  • the piston 12 is connected in the manner later described to an external power-transmission member 17 shown in figure 1 in the form of a cup-shaped element which covers the body 10 on one side and is connected to a hollow output shaft 18 from which rotary movement is derived.
  • the shaft 18 is rotatably supported coaxially to the annular chamber 11 by means of suitable bearings or bushes 19 and 20 acting both in an axial as well as a radial sense.
  • the hub 26 has a conical end 26′ which extends into a conical seating in the half-casing 10b.
  • the two half-casings 10a and 10b form a perfect join which is leak proof on the inside of the chamber 1 while, on the other hand, they provide a circular slit 21 along the most outward peripheral edges 21′ and 21 ⁇ of the two half-casings through which a bracket or fork member 22 protrudes to connect the piston 12 with the external power-transmission member 17.
  • the latter is fastened to the shaft 18 by, for example, a lock nut 23 and a screw 24 or in another effective manner.
  • a sealing element 25 in the form of an annular flexible tape which is positioned against a cylindrical sealing surface inside a recess along the peripheral edges 21′ and 21 ⁇ of the two half-casings 10a and 10b and is coaxial with the annular chamber so that the pressure of the fluid inside the chamber 11 sealingly forces the annular strip 25 against the edges of the slit 21.
  • each of the actuator's half-casings 10a and 10b has an annular race concentrically arranged to the shaft 18, which delimits one side of the internal chamber 11 of the actuator; at the same time the half-­shell 10a has a hollow central hub 26 to support the hollow shaft 18 as well as an annular rib 27 on which may be fastened and adjusted, in the right position, at least one stopping or shock-absorbing element 28 which can be adjusted to the required angular position by sliding it along the rib 27 and clamping it, for example, by means of a pair of threaded dowels 29.
  • the power-transmission element 17, has a projecting part 30 that strikes against the stopping or shock-absorbing element 28. In this way the amplitude of the angular oscillations of the power-­transmission member 17 - and therefore the piston stroke - can be controlled and adjusted, so preventing the latter from colliding against the partition wall 13 of the angular chamber 11.
  • the piston's stroke may be adjusted to within a broad angular range whose maximum value may be equal or over 280°, said maximum angle depending on the thickness of the partition wall 13 and the piston length 12.
  • the piston 12 on its radially outer side facing the annular sealing, has a longitudinal internally slot 12a which, through the reciprocating movement of the piston allows the sealing strip 25 to be drawn away from the slit 21 in correspondence with the connecting bracket or fork 22 between the piston 12 and the external power-transmission member 17.
  • reference number 31 indicates the two lip-type annular gaskets at each end of the piston 12 which form a seal against the internal walls of the annular chamber 11.
  • one of the characteristics of the rotary actuator according to this invention is the annular or toroidal shape of the chamber in which the piston slides as well as the external peripheral positioning, in a plane at right angles to the output shaft 18, of the slit 21 which is open to the passage of the connecting element 22 between the piston 12 and the external power-transmission member 17.
  • this position of the slit 21 on the radially outer circumference of the annular chamber 11 also provides the maximum lever arm of the obtainable torque, given equal actuator outside dimensions, which therefore allow maximum torque values in excess of those of a traditional actuator, given equal power and outside dimensions.
  • Figures 3 and 4 of the drawings show another characteristic of the rotary actuator according to the invention by virtue of which it is possible to eliminate all negative effects of thrust and movement discharged onto the piston and 12 and the external power-transmission member 17. This is attained by providing a loose connection - meaning that it can accomodate minor displacement in both senses of rotation between the piston 12 and the power-­transmission member 17 caused by clearances in correspondence to the connecting bracket.
  • the loose connection between the piston 12 and the member 17 is obtained by providing the latter with a rectangular opening 32 into which the folded or compressed end 22′ of the bracket or fork member 22 penetrates.
  • the folded end 22′ of the connecting bracket is also surrounded, at least on two sides, by antifrictional pads 33 which reduce friction along the opposing edges 21′ and 21 ⁇ of the slit 21. Accordingly, given that the folded portion 22′ of the bracket 22 is subject to possible oscillations and minor displacement, the stress acting on the external power-transmission member 17 can in no way affect the piston 12 and the sealing components. In this way the operating life of the actuator is greatly prolonged and performance is improved allowing fast drives and high torque values. At the same time the actuator dimensions are held to a minimum.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
EP90103845A 1989-03-06 1990-02-28 Druckmittelbetriebener Drehkolben Withdrawn EP0386598A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT8919662A IT1228969B (it) 1989-03-06 1989-03-06 Attuatore rotativo.
IT1966289 1989-03-06

Publications (1)

Publication Number Publication Date
EP0386598A1 true EP0386598A1 (de) 1990-09-12

Family

ID=11160188

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90103845A Withdrawn EP0386598A1 (de) 1989-03-06 1990-02-28 Druckmittelbetriebener Drehkolben

Country Status (4)

Country Link
EP (1) EP0386598A1 (de)
JP (1) JPH0328506A (de)
CA (1) CA2011459A1 (de)
IT (1) IT1228969B (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2312248A (en) * 1996-04-17 1997-10-22 Terry Thomas Cook Rotary actuator
WO2006096417A2 (en) * 2005-03-03 2006-09-14 Oceaneering International, Inc. Rotary actuator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2506963Y2 (ja) * 1991-03-30 1996-08-14 エスエムシー株式会社 ロッドレスシリンダ
JP2003083307A (ja) * 2001-09-13 2003-03-19 Kenichi Sakaida 揺動形アクチュエータ

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE707679C (de) * 1935-02-05 1941-06-30 Francesco Merz Zylinder fuer eine kolbenbetaetigte Beschleunigungsvorrichtung, insbesondere Flugzugschleuder
US2864341A (en) * 1957-04-04 1958-12-16 Gen Precision Lab Inc Fluid motor
DE2943505A1 (de) * 1979-10-27 1981-05-07 W. Schlafhorst & Co, 4050 Mönchengladbach Kombination zylinder-kolben
DE8710450U1 (de) * 1987-07-30 1987-09-17 Norgren Martonair GmbH, 4234 Alpen Schwenkantrieb

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE707679C (de) * 1935-02-05 1941-06-30 Francesco Merz Zylinder fuer eine kolbenbetaetigte Beschleunigungsvorrichtung, insbesondere Flugzugschleuder
US2864341A (en) * 1957-04-04 1958-12-16 Gen Precision Lab Inc Fluid motor
DE2943505A1 (de) * 1979-10-27 1981-05-07 W. Schlafhorst & Co, 4050 Mönchengladbach Kombination zylinder-kolben
DE8710450U1 (de) * 1987-07-30 1987-09-17 Norgren Martonair GmbH, 4234 Alpen Schwenkantrieb

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2312248A (en) * 1996-04-17 1997-10-22 Terry Thomas Cook Rotary actuator
WO2006096417A2 (en) * 2005-03-03 2006-09-14 Oceaneering International, Inc. Rotary actuator
US7243594B2 (en) * 2005-03-03 2007-07-17 Oceaneering International, Inc. Rotary actuator
WO2006096417A3 (en) * 2005-03-03 2007-11-15 Oceaneering Int Inc Rotary actuator
GB2438341A (en) * 2005-03-03 2007-11-21 Oceaneering Int Inc Rotary actuator
GB2438341B (en) * 2005-03-03 2010-10-20 Oceaneering Int Inc Rotary actuator

Also Published As

Publication number Publication date
JPH0328506A (ja) 1991-02-06
CA2011459A1 (en) 1990-09-06
IT8919662A0 (it) 1989-03-06
IT1228969B (it) 1991-07-11

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