GB2099080A - Fluid actuator cylinder and piston - Google Patents

Fluid actuator cylinder and piston Download PDF

Info

Publication number
GB2099080A
GB2099080A GB8213622A GB8213622A GB2099080A GB 2099080 A GB2099080 A GB 2099080A GB 8213622 A GB8213622 A GB 8213622A GB 8213622 A GB8213622 A GB 8213622A GB 2099080 A GB2099080 A GB 2099080A
Authority
GB
United Kingdom
Prior art keywords
cylinder
piston
actuator
face
arc
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
GB8213622A
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GB2099080B (en
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.)
Festo Maschinenfabrik Gottlieb Stoll Firma
Original Assignee
Festo Maschinenfabrik Gottlieb Stoll Firma
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 Festo Maschinenfabrik Gottlieb Stoll Firma filed Critical Festo Maschinenfabrik Gottlieb Stoll Firma
Publication of GB2099080A publication Critical patent/GB2099080A/en
Application granted granted Critical
Publication of GB2099080B publication Critical patent/GB2099080B/en
Expired 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
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/1414—Characterised by the construction of the motor unit of the straight-cylinder type with non-rotatable piston
    • F15B15/1419—Characterised by the construction of the motor unit of the straight-cylinder type with non-rotatable piston of non-circular cross-section
    • 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
    • F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
    • F15B15/1414—Characterised by the construction of the motor unit of the straight-cylinder type with non-rotatable piston
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J10/00—Engine or like cylinders; Features of hollow, e.g. cylindrical, bodies in general
    • F16J10/02—Cylinders designed to receive moving pistons or plungers

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Actuator (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)

Abstract

A linear actuator for use in fluid power systems has a piston (22) and a piston rod (36) running in a cylinder 10). For "keying" the piston (22) in the cylinder, the last-named has an inner flat (16) answering to a flat (26) on the piston. The inner flat (16) of the cylinder (10) is smoothly joined by radiused parts (18, 20) with a part- cylindrical part (14) of the cylinder's inner face. The piston (22) has radiused parts (28, 30) as well. <IMAGE>

Description

SPECIFICATION A fluid power linear actuator The present invention is with respect to a fluid power linear actuator having a cylinder and a piston, with a piston rod, which may not be turned in relation to the cylinder.
In the case of one prior art piston and cylinder actuator on these lines there is a guide rod, fixed parallel to and spaced from the piston rod and running in a guide sleeve fixed to the frame of the actuator, this however giving the shortcoming that the actuator has further outside moving parts which take up space and may be a danger.
In a further prior are linear actuator the piston rod is made so that it is not round in cross-section and so that it was able to be "keyed" in a noncircular opening in the end plate of the actuator, this however being responsible for sealing troubles at the opening and furthermore only small twisting forces on the piston rod may be taken up without damaging the actuator.
One purpose of the present invention is that of designing a fluid power actuatorwith the piston keyed in the cylinder in such a way that high twisting forces acting on the piston (or on the cylinder) may be taken up by the cylinder (or in the other case by the piston) by a system which is within the cylinder, without any sealing troubles.
For effecting these purposes, and further purposes, in the invention a fluid power actuator has a cylinder and a piston, the cylinder having an inner running face with a cross-section which is in the form of a circular arc joined smoothly at its ends with a chord, said smooth joins being more strongly curved than said inner face of said cylinder.
In the case of the linear actuator of the invention the "keying" effect stopping twisting of a piston in relation to the cylinder is able to be used even with high twisting torques. There are no shortcomings with respect to leaks, because the flat or chordal and cylindrical parts of the inner face of the cylinder are smoothly joined with each other. Furthermore, in comparison with a round linear actuator, the acting face of the cylinder is not much smaller, because even with a long chord, of the same order of size as the diameter of the cylinder, there will hardly be any decrease in area of the piston.
As part of one such further development an outer face of the cylinder over the chordal part of the inner cylinder face is flat and plane-parallel to said chordal inner face, this making it possible for the cylinder to be so fixed in position that it may not be twisted because its outer flat may be fixed and locked against some outer supporting structures.
Furthermore it is possible for the size of the arc as the inner face of the cylinder to have a size of 260 to 2900, this giving a good relation between, on the one hand, strong keying effects stopping twisting of the piston in the cylinder while on the other hand only causing a small decrease in the area of the piston end face.
Furthermore the cylinder may be made of extruded material, this making production of such linear actuators simpler.
An account will now be given of the invention using working examples to be seen in the figures.
Figure 1 is a cross-section through the cylinder of a pressure fluid powered linear actuator.
Figure 2 is an end-on view of one piston for use.
in the cylinder of Figure 1.
Figure 3 is a section through a somewhat changed form of the cylinder, to be used with the piston of Figure 2 as well.
Figure 1 is a cross-section through a cylinder 10 of a pressure fluid powered linear actuator. The outer face 12 of the cylinder 10 is cylindrical while the inner, running face of the cylinder 10 has a cross-section in the form of a circular arc 1 4 and a chord 1 6 smoothly joined with the ends of the arc by radiused or filleted parts 1 8 and 20.
Parts 18 and 20 are somewhat more strongly curved than arc 14 so as to give a smooth connection between chord 16 and arc 14. In the present working example the parts 1 8 and 20 are as well part-circular.
As may be seen from Figure 1 the arc 14 has a size of about 2700, such size giving the chord 1 6 a generally great length without on the other hand causing any great decrease in the inner crosssection of the cylinder 10, that is to say much less than a normal cylinder with the same diameter.
Figure 2 is an axial view of a piston 22 designed for use with cylinder 10 and having a cross-section of its outer face as arc 24 and a chord 26 joined with the ends of the arc by radiused parts 28 and 30. The size of the arc 24 is about 2700, piston 22 running with a small play ir cylinder 10.
Piston 22 has a groove 32 running round it in its outer edge to take up a seal 34. The piston is furthermore joined with a piston rod 36.
Figure 3 is a view of a somewhat changed form of cylinder 1 0 with a flat on its outer face planeparallel to the inner flat generated by chord 1 6.
This flat 38 is useful for fixing the cylinder 10 to some outer structure.
1. A fluid power actuator having a cylinder and a piston, the cylinder having an inner running face with a cross-section which is in the form of a circular arc joined smoothly at its ends with a chord, said smooth joins being more strongly curved than the rest of the inner face of the cylinder.
2. A fluid power actuator as claimed in claim 1 wherein an outerface of the cylinder has a flat which is plane-parallel to the inner part of said cylinder answering to said chord.
3. A fluid power actuator as claimed in claim 1 or claim 2 wherein said arc has a size of about 260 to 2900.
4. A fluid power actuator as claimed in anyone
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A fluid power linear actuator The present invention is with respect to a fluid power linear actuator having a cylinder and a piston, with a piston rod, which may not be turned in relation to the cylinder. In the case of one prior art piston and cylinder actuator on these lines there is a guide rod, fixed parallel to and spaced from the piston rod and running in a guide sleeve fixed to the frame of the actuator, this however giving the shortcoming that the actuator has further outside moving parts which take up space and may be a danger. In a further prior are linear actuator the piston rod is made so that it is not round in cross-section and so that it was able to be "keyed" in a noncircular opening in the end plate of the actuator, this however being responsible for sealing troubles at the opening and furthermore only small twisting forces on the piston rod may be taken up without damaging the actuator. One purpose of the present invention is that of designing a fluid power actuatorwith the piston keyed in the cylinder in such a way that high twisting forces acting on the piston (or on the cylinder) may be taken up by the cylinder (or in the other case by the piston) by a system which is within the cylinder, without any sealing troubles. For effecting these purposes, and further purposes, in the invention a fluid power actuator has a cylinder and a piston, the cylinder having an inner running face with a cross-section which is in the form of a circular arc joined smoothly at its ends with a chord, said smooth joins being more strongly curved than said inner face of said cylinder. In the case of the linear actuator of the invention the "keying" effect stopping twisting of a piston in relation to the cylinder is able to be used even with high twisting torques. There are no shortcomings with respect to leaks, because the flat or chordal and cylindrical parts of the inner face of the cylinder are smoothly joined with each other. Furthermore, in comparison with a round linear actuator, the acting face of the cylinder is not much smaller, because even with a long chord, of the same order of size as the diameter of the cylinder, there will hardly be any decrease in area of the piston. As part of one such further development an outer face of the cylinder over the chordal part of the inner cylinder face is flat and plane-parallel to said chordal inner face, this making it possible for the cylinder to be so fixed in position that it may not be twisted because its outer flat may be fixed and locked against some outer supporting structures. Furthermore it is possible for the size of the arc as the inner face of the cylinder to have a size of 260 to 2900, this giving a good relation between, on the one hand, strong keying effects stopping twisting of the piston in the cylinder while on the other hand only causing a small decrease in the area of the piston end face. Furthermore the cylinder may be made of extruded material, this making production of such linear actuators simpler. An account will now be given of the invention using working examples to be seen in the figures. Figure 1 is a cross-section through the cylinder of a pressure fluid powered linear actuator. Figure 2 is an end-on view of one piston for use. in the cylinder of Figure 1. Figure 3 is a section through a somewhat changed form of the cylinder, to be used with the piston of Figure 2 as well. Figure 1 is a cross-section through a cylinder 10 of a pressure fluid powered linear actuator. The outer face 12 of the cylinder 10 is cylindrical while the inner, running face of the cylinder 10 has a cross-section in the form of a circular arc 1 4 and a chord 1 6 smoothly joined with the ends of the arc by radiused or filleted parts 1 8 and 20. Parts 18 and 20 are somewhat more strongly curved than arc 14 so as to give a smooth connection between chord 16 and arc 14. In the present working example the parts 1 8 and 20 are as well part-circular. As may be seen from Figure 1 the arc 14 has a size of about 2700, such size giving the chord 1 6 a generally great length without on the other hand causing any great decrease in the inner crosssection of the cylinder 10, that is to say much less than a normal cylinder with the same diameter. Figure 2 is an axial view of a piston 22 designed for use with cylinder 10 and having a cross-section of its outer face as arc 24 and a chord 26 joined with the ends of the arc by radiused parts 28 and 30. The size of the arc 24 is about 2700, piston 22 running with a small play ir cylinder 10. Piston 22 has a groove 32 running round it in its outer edge to take up a seal 34. The piston is furthermore joined with a piston rod 36. Figure 3 is a view of a somewhat changed form of cylinder 1 0 with a flat on its outer face planeparallel to the inner flat generated by chord 1 6. This flat 38 is useful for fixing the cylinder 10 to some outer structure. CLAIMS
1. A fluid power actuator having a cylinder and a piston, the cylinder having an inner running face with a cross-section which is in the form of a circular arc joined smoothly at its ends with a chord, said smooth joins being more strongly curved than the rest of the inner face of the cylinder.
2. A fluid power actuator as claimed in claim 1 wherein an outerface of the cylinder has a flat which is plane-parallel to the inner part of said cylinder answering to said chord.
3. A fluid power actuator as claimed in claim 1 or claim 2 wherein said arc has a size of about 260 to 2900.
4. A fluid power actuator as claimed in anyone of claims 1 to 3 wherein said cylinder is made of extruded material.
5. A fluid power actuator as claimed in claim 1 substantially as described above with reference to Figures 1 and 2 of the drawings of the specification.
6. A fluid power actuator as claimed in claim 1 substantially as described above with reference to Figures 2 and 3 of the drawings of the specification.
GB8213622A 1981-05-21 1982-05-11 Fluid actuator cylinder and piston Expired GB2099080B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19813120157 DE3120157A1 (en) 1981-05-21 1981-05-21 "WORK CYLINDERS WITH ANTI-TWIST"

Publications (2)

Publication Number Publication Date
GB2099080A true GB2099080A (en) 1982-12-01
GB2099080B GB2099080B (en) 1984-08-30

Family

ID=6132845

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8213622A Expired GB2099080B (en) 1981-05-21 1982-05-11 Fluid actuator cylinder and piston

Country Status (4)

Country Link
JP (1) JPS57200708A (en)
DE (1) DE3120157A1 (en)
FR (1) FR2506403B1 (en)
GB (1) GB2099080B (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2561560A1 (en) * 1984-03-24 1985-09-27 Festo Kg DEVICE FOR ADVANCING AND / OR DRIVING OF THE SLIDE TYPE
EP0212421A2 (en) * 1985-08-16 1987-03-04 Knorr-Bremse Ag Pressure fluid drivable cylinder
US4667576A (en) * 1980-06-14 1987-05-26 Barmag Ag Friction yarn false twisting apparatus
US5562393A (en) * 1993-09-06 1996-10-08 Focke & Co. (Gmbh & Co.) Handling apparatus having a retractable and extendable telescopic part
US5755471A (en) * 1996-02-16 1998-05-26 Micron Electronics, Inc. Actuator stem and actuator design having a D-shaped cross-section
US20090301570A1 (en) * 2005-09-02 2009-12-10 Hiroshige Akiyama Air Intake Device For Engine
US8544699B2 (en) 2010-01-12 2013-10-01 Graco Minnesota Inc. Non-rotating single post ram for inductor pump
CN108026946A (en) * 2015-09-21 2018-05-11 雄克有限公司 Apparatus for fastening or self-winding parts with piston

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4829881A (en) * 1987-03-12 1989-05-16 Ckd Corporation Rod-less cylinder
JP3497901B2 (en) * 1994-11-10 2004-02-16 Ｓｍｃ株式会社 Rodless cylinder
CN102602021B (en) * 2012-01-06 2015-01-28 肇庆市志成气动有限公司 Pneumatic punching machine

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2985140A (en) * 1958-06-20 1961-05-23 Sophie A Fagge Hydraulic spot welding gun motor
DE2431706A1 (en) * 1974-07-02 1976-01-22 Festo Maschf Stoll G WORKING CYLINDERS FOR PNEUMATIC AND HYDRAULIC MEDIA
DE2519251A1 (en) * 1975-04-30 1976-11-11 Reinhold Pilzecker Working appliance with piston and cylinder - has piston rod and cylinder aperture of non-circular section to prevent turning
US3994539A (en) * 1975-07-22 1976-11-30 Robomation Corporation Self-contained activated slide apparatus and methods of constructing and utilizing same

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4667576A (en) * 1980-06-14 1987-05-26 Barmag Ag Friction yarn false twisting apparatus
US4803915A (en) * 1980-06-14 1989-02-14 Barmag Ag Friction yarn false twisting apparatus
FR2561560A1 (en) * 1984-03-24 1985-09-27 Festo Kg DEVICE FOR ADVANCING AND / OR DRIVING OF THE SLIDE TYPE
EP0212421A2 (en) * 1985-08-16 1987-03-04 Knorr-Bremse Ag Pressure fluid drivable cylinder
EP0212421A3 (en) * 1985-08-16 1987-05-20 Knorr-Bremse Ag Pressure fluid drivable cylinder
US5562393A (en) * 1993-09-06 1996-10-08 Focke & Co. (Gmbh & Co.) Handling apparatus having a retractable and extendable telescopic part
US5755471A (en) * 1996-02-16 1998-05-26 Micron Electronics, Inc. Actuator stem and actuator design having a D-shaped cross-section
US20090301570A1 (en) * 2005-09-02 2009-12-10 Hiroshige Akiyama Air Intake Device For Engine
US8307850B2 (en) * 2005-09-02 2012-11-13 Keihin Corporation Air intake device for engine
US8544699B2 (en) 2010-01-12 2013-10-01 Graco Minnesota Inc. Non-rotating single post ram for inductor pump
CN108026946A (en) * 2015-09-21 2018-05-11 雄克有限公司 Apparatus for fastening or self-winding parts with piston

Also Published As

Publication number Publication date
DE3120157A1 (en) 1982-12-09
GB2099080B (en) 1984-08-30
FR2506403B1 (en) 1986-11-21
FR2506403A1 (en) 1982-11-26
JPS57200708A (en) 1982-12-09

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Legal Events

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PCNP Patent ceased through non-payment of renewal fee