EP0499687B1 - Rodless actuator - Google Patents

Rodless actuator Download PDF

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Publication number
EP0499687B1
EP0499687B1 EP91115723A EP91115723A EP0499687B1 EP 0499687 B1 EP0499687 B1 EP 0499687B1 EP 91115723 A EP91115723 A EP 91115723A EP 91115723 A EP91115723 A EP 91115723A EP 0499687 B1 EP0499687 B1 EP 0499687B1
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EP
European Patent Office
Prior art keywords
slot
trapezoidal
band
cylinder tube
strip
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
EP91115723A
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German (de)
French (fr)
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EP0499687A1 (en
Inventor
Akio Matsui
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 SE and Co KG
PUBOT ENGINEERING Co
Original Assignee
Festo SE and Co KG
PUBOT ENGINEERING Co
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Publication date
Application filed by Festo SE and Co KG, PUBOT ENGINEERING Co filed Critical Festo SE and Co KG
Publication of EP0499687A1 publication Critical patent/EP0499687A1/en
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Publication of EP0499687B1 publication Critical patent/EP0499687B1/en
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    • 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

  • the present invention relates to a rodless cylinder, with a cylinder tube, which has a longitudinally extending slot with a substantially trapezoidal cross-section, with a with its two ends fixed to the end regions of the cylinder tube, in cross-section at least substantially trapezoidal band, which in the slot sits and slidably passes through a piston arranged in the cylinder tube, and with at least one piston ring arranged in the region of the outer circumference of the piston, which has an outer lip in contact with the underside of the band, an inner lip and in the region of the lateral edges of the piston Underside of the tape has ribs provided between the outer and inner lips.
  • Conventional rodless cylinders are known in which a longitudinally extending slot with a trapezoidal cross-section is introduced into a cylinder tube, a trapezoidal trapezoidal band, which is attached with its two ends to the ends of the cylinder tube, is inserted into the slot, and the trapezoidal band with cooperates with a piston which is slidably inserted and fitted in the cylinder tube to seal the slot of the cylinder tube with the trapezoidal band.
  • the conventional rodless cylinder of the above-mentioned type has shortcomings in that an area between the piston and the inner surface of the cylinder tube is sealed by a piston ring (an annular lip seal) which is fixed in the area of the outer periphery of the piston, that part of the Piston ring, which is in contact with the horizontal plane of the underside of the trapezoidal band, is deformed by imposing a curvature that differs from that of the inner peripheral surface of the cylinder tube.
  • a piston ring an annular lip seal
  • This rodless cylinder has a structure in which a rib 21c is provided between the outer lip 21a and the inner lip 21b of a piston ring 21 which is arranged in the area of the outer periphery of a piston 20 in such a manner that the outer lip 21a passes through the rib 21c is pressed against the inner surface of the cylinder tube 22.
  • this rodless cylinder is designed such that the two sides of a trapezoidal band 23 with a concave curvature Surfaces are provided, with the result that the underside of the trapezoidal band 23 in the state acted upon by the piston ring 21 is easily deformable according to the curvature of the inner surface of the cylinder tube. This prevents the outer lip 21a from being bent, thus reducing the pressure medium leakage.
  • the known rodless cylinder explained above has shortcomings in that - as shown in FIG. 10 - a corner-shaped section A is formed at a location of the trapezoidal band 23 engaging in the slot 24 from the inner surface of the cylinder tube 22, so that a lower sharp-edged one Portion of the trapezoidal band 23 protrudes slightly inward beyond the inner surface of the cylinder tube and creates a level difference due to size tolerances between the trapezoidal band 23 and the slot 24, resulting in a gap or gap C between the outer lip 21a of the piston ring 21 and the inner surface of the cylinder tube results and therefore pressure medium tends to pass through this space C.
  • a rodless cylinder which is designed such that the leakage of pressure medium from the cylinder tube is reduced even further.
  • GB-A-2 202 587 discloses a rodless cylinder which has a relatively complicated shaped sealing tape to seal the slot. It has an upper flat section which abuts protrusions of the diaphragm walls. Furthermore, it is on the lateral edges of its underside with sealing lips provided that work together with sloping guide surfaces. The guide surfaces have the task of supporting transversely movable holding ribs of the sealing tape when it is inserted into the slot.
  • a rodless working cylinder is also known, the sealing band of which is constructed similarly to that of the conventional rodless cylinder described at the beginning.
  • the sealing tape bears with upper flat sections on projections of the diaphragm walls. So that the sealing tape does not sag even when the cylinder chamber is depressurized, it is detachably fixed with hook-like projections in the area of the outer edge of the slot.
  • the present invention has for its object to provide a rodless cylinder, in which the leakage of pressure medium in the area of the tape used to seal the slot is reduced regardless of certain dimensional deviations between the tape and the slot.
  • the two side walls of the substantially trapezoidal cross-section slot have a convexly curved design in the area provided for sealing contact with the band, and that the convexly curved side walls of the slot each in Merging into a gentle curve or smoothly into the inner surface of the cylinder barrel.
  • the rodless cylinder according to the present invention operates as follows.
  • the piston ring in question which is generally a U-shaped lip seal with an axially directed U opening, is attached to the outer circumference of the piston, and the ribs are located between the outer and inner lips of the piston ring , which abuts near the two edge regions of the underside of the trapezoidal band, so that even in a state when the outer lip is pressed and bent over the underside or the bottom of the trapezoidal band, this outer lip of the ribs against the inner surface of the Cylinder is pressed to prevent the formation of a space that normally likes to form between the outer lip and the inner surface of the cylinder tube. In this way, the leakage of pressure medium is minimized.
  • the two slit sides of the slit having a substantially trapezoidal cross section are held in a convexly curved configuration, and the two side walls of the slit are connected to the inner peripheral surface of the cylinder tube to form a smooth, smooth transition curve.
  • no space is formed between the outer lip of the piston ring and the inner surface of the cylinder tube if the trapezoidal band is not seated correctly in the slot and therefore the lower, edge-containing section of the trapezoidal band slightly projects inward beyond the inner surface of the cylinder tube , for example due to dimensional deviations between the trapezoidal band and the slot or due to the ingress of dust or the like. This can further reduce the leakage of pressure medium from the cylinder barrel.
  • strip-shaped or strip-like projections are provided on the side walls of the slot which has a substantially trapezoidal cross section for holding the trapezoidal tape in a clamped manner.
  • the portions of the band which are in a position outside of the piston and inside the cylinder tube are thus able to be pressed between the projections in order to be held correctly within the slot.
  • the band is kept from sagging in the cylinder tube in order to reduce the leakage of pressure medium through the slot.
  • Figure 1 shows a longitudinal section of a rodless cylinder.
  • a cylinder tube 1 is closed at both ends by cylinder cover 2 and in a section of the cylinder tube 1 arranged at the top in FIG Slot 3 introduced such that it has a substantially trapezoidal cross-sectional configuration, the radially outer periphery of which forms the upper base (shorter side).
  • the two side walls of the slit 3 having a substantially trapezoidal or trapezoidal cross section are configured with a convexly curved configuration, so that the two side walls of the slit 3 formed by the cylinder tube are connected to the inner peripheral surface of the cylinder tube 1 to form a gentle curve are.
  • the trapezoidal or trapezoidal band 4 is a band inserted into the slot 3 from the inside of the cylinder.
  • the upper part of the trapezoidal band 4 is provided with one or more projections to be clamped between the above-mentioned projections and is fixed at both ends to the two ends of the cylinder tube 1.
  • the trapezoidal band 4 consists of plastic or synthetic resin and / or other reinforced material in order to ensure adequate elasticity and flexibility as well as advantageous sliding properties.
  • the trapezoidal band 4 is shaped so that, as shown in Figure 5, the two starting from the top in the direction of the bottom, sides that spread out in a fan shape are designed with concavely curved surfaces 4 a. The wider base of the band 4 thus points radially inward when installed.
  • a piston 5 to be inserted and fitted into the cylinder tube 1 is constructed such that end portions or end blocks 7 are arranged on both ends of a tubular main body 6 and the end blocks or other parts are clamped by means of a through bolt 8 which passes through the center of the main body 6 runs through.
  • Piston rings 10 are inserted into annular grooves, which are formed on both sides of the main body 6 in pairs in succession in the outer circumference of the respective end block 7.
  • an insertion opening 9 is excluded, through which the trapezoidal band 4 enters and exits obliquely in the longitudinal direction of the main body.
  • a coupling part 11 is protruding, which projects through the slot 3 to the outside.
  • a groove is provided in a portion of the respective end block 7, which is designed in such a manner that the wider base of the trapezoidal band 4 can slide smoothly, and a groove is also provided in a lower portion of the coupling member 11 , which is designed in such a way that, as can be seen in FIG. 2, the trapezoidal band 4 can slide smoothly along. Furthermore, a groove is provided in an upper section of the coupling part 11, along which the dirt sealing tape or cover tape 16 can slide.
  • the piston ring 10 is made of a high polymer elastomer such as artificial rubber or the like and, as shown in Figures 6 and 7, is provided with an inner lip 10a and an outer lip 10b, two ribs or projections or reinforcements at certain points between the inner Lip 10a and the outer lip 10b are arranged.
  • the two aforementioned ribs 10c are provided in order to avoid the formation of a space which could arise due to excessive bending of the outer lip 10b, which is in contact with the vicinity of the two lateral areas of the underside of the trapezoidal band 4, or due to one Level difference between the underside of the trapezoidal band 4 and the inner surface of the cylinder tube 1 could arise, which is caused by the dimensional tolerance of the trapezoidal band 4 and the slot 3 in a case when the upper outer portion of the piston ring 10 against the underside of the trapezoidal band 4 pressed and deformed as shown in Figure 3.
  • the ribs are arranged in the area of the outer lip 10b between this and the inner lip 10a in which the lip 10b is in contact with the underside of the trapezoidal band 4 in the vicinity of the two side walls.
  • the ribs 10c may have been integrally formed in the manufacture of the piston ring or may be arranged subsequently on the piston ring, for example by arranging parts of suitable dimensions at the corresponding points on the piston ring and fixing or gluing them to the same.
  • a plate 14 is fixed horizontally on the coupling part 11 projecting upward from the slot 3 of the cylinder tube 1, and dust and dirt wipers 15 are attached to the front and rear end portions of the plate 14, which slide along the masking tape 16 while they are at the same time press this band 14 down towards slot 3.
  • the masking tape 16 is a tape that closes the slot 3 in the cylinder tube 1 from the outside in order to retain contaminants. It preferably consists of a band-shaped stainless steel plate and a projection 16a made of synthetic resin, which is attached to the lower surface of the stainless steel plate as shown in FIG.
  • the cover tape 16 is with its two ends on the inside the cylinder cover 2 is fixed in the same manner as the trapezoidal band 4 and runs along the upper groove in the coupling part 11 to close the outside of the slot 3 in the longitudinal direction.
  • the projection 16a is clamped within the slot 3 between the projections 13 arranged on both longitudinal sides of the slot 3 or is laterally fixed and held.
  • a pressure medium line serving the compressed air supply is connected to a connection opening formed in the cylinder head 2 and serving the compressed air supply, and an object to be moved is coupled or coupled to the plate 14 arranged on the coupling part 11 protruding from the cylinder tube 1 connected. If pressure medium is then supplied via the connection opening, fluid pressure is applied to the right end of the piston 5 shown in FIG. 1, as a result of which the piston 5 is moved to the left.
  • the trapezoidal band 4 is held by the strip projections 12, 12 clamping within the slot, so that the trapezoidal band 4 never sags down into the inside of the cylinder tube 1 and the fluid pressure that is present traps the trapezoidal band 4 from the inside of the cylinder tube Push slot 3 in to securely seal slot 3.
  • the piston cups 10 seal the boundary between the piston 5, the inner surface of the cylinder tube 1 and the underside of the trapezoidal band 4.
  • the upper portion of the piston ring 10 is pressed against the underside of the trapezoidal band 4 and thereby deformed, whereby a gap or gap easily arises near the two side edges of the underside of the trapezoidal band 4, that is, in an outer edge region of the outer lip 10b is folded over from a curved section to a flat section.
  • this area is reinforced by the ribs 10c to prevent the outer lip 10b from tilting inward, whereby the border area between the outer lip 10b in the area of both longitudinal sides of the underside of the trapezoidal band 4 and the inner surface of the Cylinder tube 1 is advantageously sealed.
  • the two side walls or side surfaces of the slot 3 are designed in a convexly curved or curved design and each pass in the course of a slight or flat curve into the inner surface of the cylinder tube 1, so that even if the lower sharp-edged region of the trapezoidal band 4 is light protrudes inward from the inner surface of the cylinder tube - due to dimensional tolerances between the trapezoidal band 4 and the Slit 3 -, no space between the outer lip 10b of the piston ring 10 and the inner surface of the cylinder tube 1 is generated and thereby the leakage of the pressure medium can be minimized.
  • the trapezoidal band 4 has a substantially trapezoidal cross-section, on which its name is based, so that the pressure force acting on the trapezoidal band 4 increases the higher the pressure prevailing within the cylinder, whereby the advantageous sealing effect is achieved.
  • the trapezoidal band 4 is hardly exposed to the actuating force of the piston 5, so that it never expands and contracts, which is why no harmful effects are derived from a possible expansion and contraction of the trapezoidal band 4.
  • Compressed air is particularly suitable as a pressure source for the rodless cylinder of the present invention.
  • this rodless cylinder can also be operated under low hydraulic pressure.
  • the two side walls of the approximately trapezoidal cross-sectional slit are formed in a convexly curved configuration, and the two side walls of the slit are in contact with the inner peripheral surface of the cylinder tube to form a gentle curve or curve Rounding in connection, even if the trapezoidal band is not correctly fitted into the slot due to dimensional deviations on its part and / or the slot or due to the penetration of dirt, and therefore the lower angular section of the trapezoidal band slightly behind the inner surface of the cylinder tube protrudes inside, there is no gap or space between the outer lip of the piston ring and the inner surface of the cylinder tube, so that the leakage of pressure medium from the cylinder tube is reduced.
  • the strip-shaped projections are between clamping and holding the trapezoidal band on the upper or radially outer portions of the two side walls of the substantially trapezoidal cross-section slot, so that the portion of the trapezoidal band that comes to lie outside the piston is clamped inside the cylinder tube between the projections and is correctly held within the slot. In this way the sagging of the band inside the cylinder tube can be prevented and the leakage of pressure medium through the slot can be reduced.
  • the diaphragm walls are expediently formed by the sections of the cylinder tube which delimit the slot along the longitudinal side - there is preferably such a configuration that the slot width widens from a radially central slot area towards the interior of the cylinder tube, as shown in FIG the figure 4 is expressed.
  • the contouring of the side walls or side surfaces of the slot 3 is expediently at least substantially complementary to the contouring of the concave side surfaces 4a of the trapezoidal band 4.

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

Description

Die vorliegende Erfindung bezieht sich auf einen kolbenstangenlosen Zylinder, mit einem Zylinderrohr, das einen in Längsrichtung verlaufenden Schlitz mit im wesentlichen trapezförmigem Querschnitt aufweist, mit einem mit seinen beiden Enden an den Endbereichen des Zylinderrohres festgelegten, im Querschnitt zumindest im wesentlichen trapezförmigen Band, das in dem Schlitz einsitzt und verschiebbar durch einen in dem Zylinderrohr angeordneten Kolben hindurchgeht, und mit mindestens einem im Bereich des Außenumfanges des Kolbens angeordneten Kolbenring, der eine mit der Unterseite des Bandes in Anlage stehende äußere Lippe, eine innere Lippe und im Bereich der seitlichen Ränder der Unterseite des Bandes zwischen der äußeren und der inneren Lippe vorgesehene Rippen aufweist.The present invention relates to a rodless cylinder, with a cylinder tube, which has a longitudinally extending slot with a substantially trapezoidal cross-section, with a with its two ends fixed to the end regions of the cylinder tube, in cross-section at least substantially trapezoidal band, which in the slot sits and slidably passes through a piston arranged in the cylinder tube, and with at least one piston ring arranged in the region of the outer circumference of the piston, which has an outer lip in contact with the underside of the band, an inner lip and in the region of the lateral edges of the piston Underside of the tape has ribs provided between the outer and inner lips.

Es sind konventionelle kolbenstangenlose Zylinder bekannt, bei denen ein sich in Längsrichtung erstreckender Schlitz mit trapezförmigem Querschnitt in ein Zylinderrohr eingebracht ist, ein trapezförmiges, mit seinen beiden Enden an den Enden des Zylinderrohres befestigtes trapezförmiges Band in den Schlitz eingesetzt ist, und das trapezförmige Band mit einem Kolben zusammenarbeitet, der verschiebbar in das Zylinderrohr eingesetzt und eingepaßt ist, um den Schlitz des Zylinderrohres mit dem trapezförmigen Band abzudichten.Conventional rodless cylinders are known in which a longitudinally extending slot with a trapezoidal cross-section is introduced into a cylinder tube, a trapezoidal trapezoidal band, which is attached with its two ends to the ends of the cylinder tube, is inserted into the slot, and the trapezoidal band with cooperates with a piston which is slidably inserted and fitted in the cylinder tube to seal the slot of the cylinder tube with the trapezoidal band.

Der konventionelle kolbenstangenlose Zylinder der vorstehend erwähnten Art hat jedoch insofern Unzulänglichkeiten, als ein Bereich zwischen dem Kolben und der inneren Oberfläche des Zylinderrohres mittels eines Kolbenringes (eine ringförmige Lippendichtung) abgedichtet ist, welcher im Bereich des Außenumfanges des Kolbens festgelegt ist, wobei derjenige Teil des Kolbenringes, welcher in Anpreßkontakt mit der horizontalen Ebene der Unterseite des trapezförmigen Bandes steht, unter Auferlegung einer Krümmung deformiert wird, die sich von derjenigen der inneren Umfangsfläche des Zylinderrohres unterscheidet. Wenn das in den Schlitz eingesetzte trapezförmige Band aufgrund von Abmessungstoleranzen nicht mit dem Schlitzgrund fluchtet, wird ein Höhenunterschied zwischen der Unterseite des trapezförmigen Bandes und der Innenoberfläche des Zylinderrohres hervorgerufen, so daß das Druckmittel, welches in das Zylinderrohr zugeführt wird, durch den infolge der erwähnten Höhendifferenz entstandenen Zwischenraum entweicht.However, the conventional rodless cylinder of the above-mentioned type has shortcomings in that an area between the piston and the inner surface of the cylinder tube is sealed by a piston ring (an annular lip seal) which is fixed in the area of the outer periphery of the piston, that part of the Piston ring, which is in contact with the horizontal plane of the underside of the trapezoidal band, is deformed by imposing a curvature that differs from that of the inner peripheral surface of the cylinder tube. If the trapezoidal band inserted into the slot does not align with the bottom of the slot due to dimensional tolerances, a height difference is produced between the underside of the trapezoidal band and the inner surface of the cylinder tube, so that the pressure medium which is fed into the cylinder tube is caused by the result of the mentioned Height difference created escapes.

Es wurde daher bereits in der JP-A-62/184208 ein kolbenstangenloser Zylinder der eingangs genannten Art vorgeschlagen, wie er in Figur 9 der beigefügten Zeichnung abgebildet ist. Dieser kolbenstangenlose Zylinder besitzt einen Aufbau, bei dem eine Rippe 21c zwischen der äußeren Lippe 21a und der inneren Lippe 21b eines Kolbenringes 21 vorgesehen ist, welcher im Bereich des Außenumfanges eines Kolbens 20 in einer Art und Weise angeordnet ist, daß die äußere Lippe 21a durch die Rippe 21c gegen die Innenoberfläche des Zylinderrohres 22 gedrückt wird. Außerdem ist dieser kolbenstangenlose Zylinder derart ausgebildet, daß die beiden Seiten eines trapezförmigen Bandes 23 mit konkav gekrümmten Oberflächen versehen sind, was zur Folge hat, daß die Unterseite des trapezförmigen Bandes 23 im vom Kolbenring 21 beaufschlagten Zustand leicht entsprechend der Krümmung der Innenoberfläche des Zylinderrohres deformierbar ist. Dadurch wird verhindert, daß die äußere Lippe 21a abgebogen wird, womit sich die Leckage des Druckmittels reduziert.It has therefore already been proposed in JP-A-62/184208 a rodless cylinder of the type mentioned at the outset, as shown in FIG. 9 of the accompanying drawing. This rodless cylinder has a structure in which a rib 21c is provided between the outer lip 21a and the inner lip 21b of a piston ring 21 which is arranged in the area of the outer periphery of a piston 20 in such a manner that the outer lip 21a passes through the rib 21c is pressed against the inner surface of the cylinder tube 22. In addition, this rodless cylinder is designed such that the two sides of a trapezoidal band 23 with a concave curvature Surfaces are provided, with the result that the underside of the trapezoidal band 23 in the state acted upon by the piston ring 21 is easily deformable according to the curvature of the inner surface of the cylinder tube. This prevents the outer lip 21a from being bent, thus reducing the pressure medium leakage.

Allerdings hat der vorstehend erläuterte bekannte kolbenstangenlose Zylinder insofern Unzulänglichkeiten, als - wie in Figur 10 gezeigt - ein eckförmiger Abschnitt A an einer Stelle des von der Innenoberfläche des Zylinderrohres 22 her in den Schlitz 24 eingreifenden trapezförmigen Bandes 23 ausgebildet ist, so daß ein unterer scharfkantiger Abschnitt des trapezförmigen Bandes 23 geringfügig nach innen über die Innenoberfläche des Zylinderrohres vorsteht und aufgrund von Größentoleranzen zwischen dem trapezförmigen Band 23 und dem Schlitz 24 einen Niveauunterschied erzeugt, woraus ein Zwischenraum oder Spalt C zwischen der äußeren Lippe 21a des Kolbenringes 21 und der Innenoberfläche des Zylinderrohres resultiert und deshalb Druckmittel dazu neigt, durch diesen Zwischenraum C hindurchzutreten. Es besteht daher Bedarf nach einem kolbenstangenlosen Zylinder, der dahingehend ausgebildet ist, daß die Leckage von Druckmittel aus dem Zylinderrohr noch weiter reduziert ist.However, the known rodless cylinder explained above has shortcomings in that - as shown in FIG. 10 - a corner-shaped section A is formed at a location of the trapezoidal band 23 engaging in the slot 24 from the inner surface of the cylinder tube 22, so that a lower sharp-edged one Portion of the trapezoidal band 23 protrudes slightly inward beyond the inner surface of the cylinder tube and creates a level difference due to size tolerances between the trapezoidal band 23 and the slot 24, resulting in a gap or gap C between the outer lip 21a of the piston ring 21 and the inner surface of the cylinder tube results and therefore pressure medium tends to pass through this space C. There is therefore a need for a rodless cylinder which is designed such that the leakage of pressure medium from the cylinder tube is reduced even further.

Aus der GB-A-2 202 587 geht ein kolbenstangenloser Zylinder hervor, der zur Abdichtung des Schlitzes über ein relativ kompliziert geformtes Dichtband verfügt. Es hat einen oberen ebenen Abschnitt, der an Vorsprüngen der Schlitzwände anliegt. Ferner ist es an den seitlichen Rändern seiner Unterseite mit Dichtlippen versehen, die mit schrägen Führungsflächen zusammenarbeiten. Die Führungsflächen haben die Aufgabe, querbewegliche Halterippen des Dichtbandes beim Einführen in den Schlitz zu unterstützen.GB-A-2 202 587 discloses a rodless cylinder which has a relatively complicated shaped sealing tape to seal the slot. It has an upper flat section which abuts protrusions of the diaphragm walls. Furthermore, it is on the lateral edges of its underside with sealing lips provided that work together with sloping guide surfaces. The guide surfaces have the task of supporting transversely movable holding ribs of the sealing tape when it is inserted into the slot.

Es ist ferner aus der GB-A-2 163 499 ein kolbenstangenloser Arbeitszylinder bekannt, dessen Dichtband ähnlich dem des eingangs geschilderten konventionellen kolbenstangenlosen Zylinders aufgebaut ist. Zusätzlich liegt das Dichtband aber wie im Falle der GB-A-2 202 587 mit oberen ebenen Abschnitten an Vorsprüngen der Schlitzwände an. Damit das Dichtband auch im drucklosen Zustand des Zylinderraumes nicht durchhängt, ist es mit hakenartigen Vorsprüngen im Bereich des äußeren Schlitzrandes lösbar fixiert.From GB-A-2 163 499 a rodless working cylinder is also known, the sealing band of which is constructed similarly to that of the conventional rodless cylinder described at the beginning. In addition, however, as in the case of GB-A-2 202 587, the sealing tape bears with upper flat sections on projections of the diaphragm walls. So that the sealing tape does not sag even when the cylinder chamber is depressurized, it is detachably fixed with hook-like projections in the area of the outer edge of the slot.

Der vorliegenden Erfindung liegt die Aufgabe zugrunde, einen kolbenstangenlosen Zylinder zu schaffen, bei dem die Leckage von Druckmittel im Bereich des zur Abdichtung des Schlitzes dienenden Bandes unabhängig von gewissen Maßabweichungen zwischen dem Band und dem Schlitz reduziert ist.The present invention has for its object to provide a rodless cylinder, in which the leakage of pressure medium in the area of the tape used to seal the slot is reduced regardless of certain dimensional deviations between the tape and the slot.

Zur Lösung dieser Aufgabe ist gemäß dem kennzeichnenden Teil des Patentanspruches 1 vorgesehen, daß die beiden Seitenwände des im wesentlichen trapezförmigen Querschnitt aufweisenden Schlitzes in dem zum Dichtkontakt mit dem Band vorgesehenen Bereich eine konvex gekrümmte Gestaltung aufweisen, und daß die konvex gekrümmten Seitenwände des Schlitzes jeweils im Rahmen einer sanften Kurve oder fließend in die Innenoberfläche des Zylinderrohres übergehen.To solve this problem it is provided according to the characterizing part of claim 1 that the two side walls of the substantially trapezoidal cross-section slot have a convexly curved design in the area provided for sealing contact with the band, and that the convexly curved side walls of the slot each in Merging into a gentle curve or smoothly into the inner surface of the cylinder barrel.

Zweckmäßige Weiterbildungen der Erfindung ergeben sich aus den abhängigen Ansprüchen 2 bis 4.Appropriate developments of the invention result from the dependent claims 2 to 4.

Der kolbenstangenlose Zylinder gemäß der vorliegenden Erfindung arbeitet wie folgt.The rodless cylinder according to the present invention operates as follows.

Der betreffende Kolbenring, bei welchem es sich in der Regel um einen im Querschnitt U-förmigen Lippen-Dichtring mit axial gerichteter U-Öffnung handelt, ist am Außenumfang des Kolbens angebracht, und die Rippen befinden sich zwischen der äußeren und der inneren Lippe des Kolbenringes, der in der Nähe der beiden Randbereiche der Unterseite des trapezförmigen Bandes anliegt, so daß selbst in einem Zustand, wenn die äußere Lippe gegen die Unterseite beziehungsweise den Grund des trapezoidalen Bandes gedrückt und umgebogen wird, diese äußere Lippe von den Rippen gegen die Innenoberfläche des Zylinders gedrückt wird, um die Bildung eines Zwischenraumes zu verhindern, der sich normalerweise gerne zwischen der äußeren Lippe und der Innenoberfläche des Zylinderrohres bildet. Auf diese Weise ist die Leckage von Druckmittel minimiert. Zusätzlich sind die beiden Schlitzseiten des im wesentlichen trapezförmigen Querschnitt aufweisenden Schlitzes in konvex gekrümmter Konfiguration gehalten und die beiden Seitenwände des Schlitzes sind mit der Innenumfangsfläche des Zylinderrohres unter Bildung einer sanften, fließend übergehenden Kurve verbunden. Auf diese Weise bildet sich selbst dann kein Zwischenraum zwischen der äußeren Lippe des Kolbenringes und der Innenoberfläche des Zylinderrohres, wenn das trapezförmige Band nicht korrekt im Schlitz einsitzt und deswegen der untere, Kanten aufweisende Abschnitt des trapezförmigen Bandes leicht nach innen über die Innenoberfläche des Zylinderrohres vorsteht, und zwar zum Beispiel aufgrund von Maßabweichungen zwischen dem trapezförmigen Band und dem Schlitz oder aufgrund des Eindringens von Staub oder dergleichen. Dadurch kann die Leckage von Druckmittel aus dem Zylinderrohr weiter reduziert werden.The piston ring in question, which is generally a U-shaped lip seal with an axially directed U opening, is attached to the outer circumference of the piston, and the ribs are located between the outer and inner lips of the piston ring , which abuts near the two edge regions of the underside of the trapezoidal band, so that even in a state when the outer lip is pressed and bent over the underside or the bottom of the trapezoidal band, this outer lip of the ribs against the inner surface of the Cylinder is pressed to prevent the formation of a space that normally likes to form between the outer lip and the inner surface of the cylinder tube. In this way, the leakage of pressure medium is minimized. In addition, the two slit sides of the slit having a substantially trapezoidal cross section are held in a convexly curved configuration, and the two side walls of the slit are connected to the inner peripheral surface of the cylinder tube to form a smooth, smooth transition curve. In this way, no space is formed between the outer lip of the piston ring and the inner surface of the cylinder tube if the trapezoidal band is not seated correctly in the slot and therefore the lower, edge-containing section of the trapezoidal band slightly projects inward beyond the inner surface of the cylinder tube , for example due to dimensional deviations between the trapezoidal band and the slot or due to the ingress of dust or the like. This can further reduce the leakage of pressure medium from the cylinder barrel.

In bevorzugter Ausbildung der Erfindung sind an den Seitenwänden des im wesentlichen trapezförmigen Querschnitt aufweisenden Schlitzes leisten- oder streifenförmige Vorsprünge zum klemmenden Halten des trapezförmigen Bandes vorgesehen. Die Abschnitte des Bandes, die sich in einer Position außerhalb des Kolbens und innerhalb des Zylinderrohres befinden, sind somit zwischen die Vorsprünge eindrückbar, um innerhalb des Schlitzes korrekt gehalten zu werden. Dabei wird das Band zugleich vor einem Durchhängen in das Zylinderrohr abgehalten, um die Leckage von Druckmittel durch den Schlitz zu reduzieren.In a preferred embodiment of the invention, strip-shaped or strip-like projections are provided on the side walls of the slot which has a substantially trapezoidal cross section for holding the trapezoidal tape in a clamped manner. The portions of the band which are in a position outside of the piston and inside the cylinder tube are thus able to be pressed between the projections in order to be held correctly within the slot. At the same time, the band is kept from sagging in the cylinder tube in order to reduce the leakage of pressure medium through the slot.

Die Erfindung wird aus der folgenden, unter Bezugnahme auf die beigefügten Zeichnungen zu lesenden Beschreibung besonders deutlich. Hierbei zeigen:

Figur 1
eine Schnittdarstellung eines kolbenstangenlosen Zylinders gemäß einer Ausführungsform der vorliegenden Erfindung;
Figur 2
eine Schnittdarstellung mit einem Schnitt entlang der Linie II-II aus Figur 1;
Figur 3
eine Schnittdarstellung mit einem Schnitt entlang der Linie III-III aus Figur 1;
Figur 4
eine vergrößerte Querschnittsdarstellung des Zylinders aus Figur 1;
Figur 5
eine perspektivische Darstellung eines trapezförmigen Bandes 4;
Figur 6
eine Vorderansicht eines Kolbenringes 10;
Figur 7
eine Schnittdarstellung des Kolbenringes 10;
Figur 8
eine perspektivische Darstellung eines Abdeckbandes 16 gegen Verschmutzung;
Figur 9
eine Querschnittsdarstellung eines konventionellen kolbenstangenlosen Zylinders; und
Figur 10
eine Teil-Schnittdarstellung des konventionellen Zylinderrohres und trapezförmigen Bandes.
The invention will be more particularly apparent from the following description, to be read with reference to the accompanying drawings. Here show:
Figure 1
a sectional view of a rodless cylinder according to an embodiment of the present invention;
Figure 2
a sectional view with a section along the line II-II of Figure 1;
Figure 3
a sectional view with a section along the line III-III of Figure 1;
Figure 4
an enlarged cross-sectional view of the cylinder of Figure 1;
Figure 5
a perspective view of a trapezoidal band 4;
Figure 6
a front view of a piston ring 10;
Figure 7
a sectional view of the piston ring 10;
Figure 8
a perspective view of a masking tape 16 against contamination;
Figure 9
a cross-sectional view of a conventional rodless cylinder; and
Figure 10
a partial sectional view of the conventional cylinder tube and trapezoidal band.

Zunächst wird eine Ausführungsform der vorliegenden Erfindung unter Bezugnahme auf die beigefügten Zeichnungen beschrieben.First, an embodiment of the present invention will be described with reference to the accompanying drawings.

Die Figur 1 zeigt einen Längsschnitt eines kolbenstangenlosen Zylinders. Gemäß der Zeichnung ist ein Zylinderrohr 1 an seinen beiden Enden durch Zylinderdeckel 2 verschlossen und in einen in Figur 1 oben angeordneten Abschnitt des Zylinderrohres 1 ist umfangsseitig ein in Längsrichtung verlaufender Schlitz 3 derart eingebracht, daß er eine im wesentlichen trapezförmige Querschnittsgestaltung aufweist, deren radial äußere Peripherie die obere Basis (kürzere Seite) bildet.Figure 1 shows a longitudinal section of a rodless cylinder. According to the drawing, a cylinder tube 1 is closed at both ends by cylinder cover 2 and in a section of the cylinder tube 1 arranged at the top in FIG Slot 3 introduced such that it has a substantially trapezoidal cross-sectional configuration, the radially outer periphery of which forms the upper base (shorter side).

Wie in Figur 4 gezeigt, sind die beiden Seitenwände des im wesentlichen trapezförmigen oder trapezoidalen Querschnitt aufweisenden Schlitzes 3 mit konvex gekrümmter Konfiguration gestaltet, so daß die beiden vom Zylinderrohr gebildeten Seitenwände des Schlitzes 3 unter Bildung einer sanften Kurve mit der inneren Umfangsfläche des Zylinderrohres 1 verbunden sind. Zusätzlich sind an der Oberseite bzw. im radial äußeren Rand beider Seitenwände des Schlitzes 3 in Längsrichtung verlaufende leisten- beziehungsweise lippenförmige Vorsprünge 12 zum Klemmen und Halten des wegen seiner im wesentlichen trapezförmigen Querschnittsgestaltung als trapezförmiges Band 4 bezeichneten Bandes und leisten- beziehungsweise rippenförmige Vorsprünge 13 zum Klemmen und Halten eines Verschmutzung zurückhaltenden Abdeckbandes 16 angeformt.As shown in Fig. 4, the two side walls of the slit 3 having a substantially trapezoidal or trapezoidal cross section are configured with a convexly curved configuration, so that the two side walls of the slit 3 formed by the cylinder tube are connected to the inner peripheral surface of the cylinder tube 1 to form a gentle curve are. In addition, on the upper side or in the radially outer edge of both side walls of the slot 3, there are longitudinal strip-like or lip-shaped projections 12 for clamping and holding the band referred to as trapezoidal cross-sectional design as a trapezoidal band 4 and strip-like or rib-shaped projections 13 for Clamping and holding a dirt-retaining masking tape 16 formed.

Das trapezförmige beziehungsweise trapezoidale Band 4 ist ein von der Zylinderinnenseite her in den Schlitz 3 eingesetztes Band. Das trapezförmige Band 4 ist an oberen Abschnitten mit einem oder mehreren zwischen die oben erwähnten Vorsprünge zwischenzuklemmenden Vorsprüngen ausgestattet und ist mit beiden Enden an den beiden Endes des Zylinderrohres 1 festgelegt. Das trapezförmige Band 4 besteht aus Kunststoff oder Kunstharz und/oder anderem verstärktem Material, um angemessene Elastizität und Flexibilität sowie vorteilhafte Gleitfähigkeit zu gewährleisten. Außerdem ist das trapezförmige Band 4 so geformt, daß, wie in Figur 5 gezeigt, die beiden ausgehend von der Oberseite in Richtung zur Unterseite sich fächerförmig auseinanderspreizenden Seiten mit konkav gewölbten Oberflächen 4a gestaltet sind. Die breitere Basis des Bandes 4 weist also im eingebauten Zustand nach radial innen.The trapezoidal or trapezoidal band 4 is a band inserted into the slot 3 from the inside of the cylinder. The upper part of the trapezoidal band 4 is provided with one or more projections to be clamped between the above-mentioned projections and is fixed at both ends to the two ends of the cylinder tube 1. The trapezoidal band 4 consists of plastic or synthetic resin and / or other reinforced material in order to ensure adequate elasticity and flexibility as well as advantageous sliding properties. In addition, the trapezoidal band 4 is shaped so that, as shown in Figure 5, the two starting from the top in the direction of the bottom, sides that spread out in a fan shape are designed with concavely curved surfaces 4 a. The wider base of the band 4 thus points radially inward when installed.

Ein in das Zylinderrohr 1 einzuführender und einzupassender Kolben 5 ist derart aufgebaut, daß Endabschnitte oder Endblöcke 7 auf den beiden Enden eines rohrförmigen Hauptkörpers 6 angeordnet sind und die Endblöcke oder andere Teile mittels eines durchgehenden Bolzens 8 festgeklemmt sind, der durch das Zentrum des Hauptkörpers 6 hindurch verläuft. Kolbenringe 10 sind in ringförmig gestaltete Nuten eingesetzt, welche beidseits des Hauptkörpers 6 jeweils paarweise aufeinanderfolgend im Außenumfang des jeweiligen Endblockes 7 ausgebildet sind. Im in den Figuren oberen schlitzseitigen Abschnitt des ringförmigen Hauptkörpers 6 ist eine Einführöffnung 9 ausgenommen, durch welche das trapezförmige Band 4 in Längsrichtung des Hauptkörpers schräg ein- und austritt. An einem oberen zentralen Abschnitt des rohrförmigen Hauptkörpers 6 ist ein Kupplungsteil 11 vorspringend angeordnet, welches durch den Schlitz 3 zur Außenseite ragt.A piston 5 to be inserted and fitted into the cylinder tube 1 is constructed such that end portions or end blocks 7 are arranged on both ends of a tubular main body 6 and the end blocks or other parts are clamped by means of a through bolt 8 which passes through the center of the main body 6 runs through. Piston rings 10 are inserted into annular grooves, which are formed on both sides of the main body 6 in pairs in succession in the outer circumference of the respective end block 7. In the upper slot-side section of the annular main body 6 in the figures, an insertion opening 9 is excluded, through which the trapezoidal band 4 enters and exits obliquely in the longitudinal direction of the main body. On an upper central section of the tubular main body 6, a coupling part 11 is protruding, which projects through the slot 3 to the outside.

Zusätzlich zu dem vorgenannten ist in einem Abschnitt des jeweiligen Endblockes 7 eine Nut vorgesehen, die in einer Art und Weise gestaltet ist, daß die breitere Basis des trapezförmigen Bandes 4 gleichmäßig entlanggleiten kann, und in einem unteren Abschnitt des Kupplungselementes 11 ist ebenfalls eine Nut vorgesehen, die auf eine Weise gestaltet ist, daß, wie in Figur 2 ersichtlich, das trapezförmige Band 4 sanft entlanggleiten kann. Weiterhin ist in einem oberen Abschnitt des Kupplungsteiles 11 eine Nut vorgesehen, entlang welcher das Schmutz-Dichtband beziehungsweise Abdeckband 16 gleiten kann.In addition to the foregoing, a groove is provided in a portion of the respective end block 7, which is designed in such a manner that the wider base of the trapezoidal band 4 can slide smoothly, and a groove is also provided in a lower portion of the coupling member 11 , which is designed in such a way that, as can be seen in FIG. 2, the trapezoidal band 4 can slide smoothly along. Furthermore, a groove is provided in an upper section of the coupling part 11, along which the dirt sealing tape or cover tape 16 can slide.

Der Kolbenring 10 besteht aus einem hochpolymeren Elastomer wie künstlichem Gummi oder ähnlichem und ist, wie in den Figuren 6 und 7 gezeigt, mit einer inneren Lippe 10a und einer äußeren Lippe 10b ausgestattet, wobei zwei Rippen oder Vorsprünge beziehungsweise Verstärkungen an bestimmten Stellen zwischen der inneren Lippe 10a und der äußeren Lippe 10b angeordnet sind.The piston ring 10 is made of a high polymer elastomer such as artificial rubber or the like and, as shown in Figures 6 and 7, is provided with an inner lip 10a and an outer lip 10b, two ribs or projections or reinforcements at certain points between the inner Lip 10a and the outer lip 10b are arranged.

Die beiden vorerwähnten Rippen 10c sind vorgesehen, um das Entstehen eines Zwischenraumes zu vermeiden, der aufgrund zu starken Umbiegens der äußeren Lippe 10b entstehen könnte, welche mit des Nachbarschaft der beiden seitlichen Bereiche der Unterseite des trapezförmigen Bandes 4 in Anlage steht, oder der aufgrund eines Niveauunterschiedes zwischen der Unterseite des trapezförmigen Bandes 4 und der Innenoberfläche des Zylinderrohres 1 entstehen könnte, welcher durch die Abmessungstoleranz des trapezförmigen Bandes 4 und des Schlitzes 3 in einem Falle verursacht wird, wenn der obere äußere Abschnitt des Kolbenringes 10 gegen die Unterseite des trapezförmigen Bandes 4 gedrückt und wie in Figur 3 gezeigt verformt wird. Daher sind die Rippen in demjenigen Bereich der äußeren Lippe 10b zwischen dieser und der inneren Lippe 10a angeordnet, in welchem die Lippe 10b in der Nähe der beiden Seitenwände des trapezförmigen Bandes 4 mit dessen Unterseite in Kontakt steht. Die Rippen 10c können bei der Herstellung des Kolbenringes einstückig mit angeformt worden sein oder können nachträglich am Kolbenring angeordnet worden sein, zum Beispiel indem Teile geeigneter Abmessungen an den entsprechenden Stellen des Kolbenringes angeordnet und an selbigem festgelegt oder festgeklebt werden.The two aforementioned ribs 10c are provided in order to avoid the formation of a space which could arise due to excessive bending of the outer lip 10b, which is in contact with the vicinity of the two lateral areas of the underside of the trapezoidal band 4, or due to one Level difference between the underside of the trapezoidal band 4 and the inner surface of the cylinder tube 1 could arise, which is caused by the dimensional tolerance of the trapezoidal band 4 and the slot 3 in a case when the upper outer portion of the piston ring 10 against the underside of the trapezoidal band 4 pressed and deformed as shown in Figure 3. Therefore are the ribs are arranged in the area of the outer lip 10b between this and the inner lip 10a in which the lip 10b is in contact with the underside of the trapezoidal band 4 in the vicinity of the two side walls. The ribs 10c may have been integrally formed in the manufacture of the piston ring or may be arranged subsequently on the piston ring, for example by arranging parts of suitable dimensions at the corresponding points on the piston ring and fixing or gluing them to the same.

Eine Platte 14 ist horizontal auf dem ausgehend vom Schlitz 3 des Zylinderrohres 1 nach oben ragenden Kupplungsteil 11 festgelegt, und es sind Staub- beziehungsweise Verschmutzungs-Abstreifer 15 am vorderen und hinteren Endbereich der Platte 14 angebracht, die auf dem Abdeckband 16 entlanggleiten, während sie zugleich dieses Band 14 nach unten in Richtung zum Schlitz 3 drücken.A plate 14 is fixed horizontally on the coupling part 11 projecting upward from the slot 3 of the cylinder tube 1, and dust and dirt wipers 15 are attached to the front and rear end portions of the plate 14, which slide along the masking tape 16 while they are at the same time press this band 14 down towards slot 3.

Das Abdeckband 16 ist ein Band, das den Schlitz 3 im Zylinderrohr 1 von der Außenseite her verschließt, um Verunreinigungen zurückzuhalten. Es besteht vorzugsweise aus einer bandförmigen rostfreien Stahlplatte und einem Vorsprung 16a aus Kunstharz, welcher an der unteren Oberfläche der rostfreien Stahlplatte wie in Figur 8 gezeigt angebracht ist.The masking tape 16 is a tape that closes the slot 3 in the cylinder tube 1 from the outside in order to retain contaminants. It preferably consists of a band-shaped stainless steel plate and a projection 16a made of synthetic resin, which is attached to the lower surface of the stainless steel plate as shown in FIG.

Das Abdeckband 16 ist mit seinen beiden Enden an der Innenseite der Zylinderdeckel 2 in derselben Weise wie das trapezförmige Band 4 festgelegt und läuft entlang der oberen Nut im Kupplungsteil 11, um die Außenseite des Schlitzes 3 in Längsrichtung zu verschließen. In dem Bereich des Abdeckbandes 16, welcher sich in einer Position befindet, in welcher das Abdeckband den Schlitz 3 verschließt, ist der Vorsprung 16a innerhalb des Schlitzes 3 zwischen den an beiden Längsseiten des Schlitzes 3 angeordneten Vorsprüngen 13 geklemmt oder seitlich fixiert und gehalten.The cover tape 16 is with its two ends on the inside the cylinder cover 2 is fixed in the same manner as the trapezoidal band 4 and runs along the upper groove in the coupling part 11 to close the outside of the slot 3 in the longitudinal direction. In the region of the cover band 16, which is in a position in which the cover band closes the slot 3, the projection 16a is clamped within the slot 3 between the projections 13 arranged on both longitudinal sides of the slot 3 or is laterally fixed and held.

Bei dem in der oben geschilderten Weise ausgebildeten kolbenstangenlosen Zylinder ist eine der Druckluftversorgung dienende Druckmittelleitung an eine im Zylinderkopf 2 ausgebildete, der Druckluftzufuhr dienende Anschlußöffnung angeschlossen, und ein zu bewegender Gegenstand wird mit der an dem vom Zylinderrohr 1 abstehenden Kupplungsteil 11 angeordneten Platte 14 gekuppelt beziehungsweise verbunden. Wenn dann Druckmittel über die Anschlußöffnung zugeführt wird, wird das rechte Ende des in Figur 1 gezeigten Kolbens 5 mit Fluiddruck beaufschlagt, wodurch der Kolben 5 nach links bewegt wird. Das trapezförmige Band 4 ist von den Streifen-Vorsprüngen 12, 12 innerhalb des Schlitzes klemmend gehalten, so daß das trapezförmige Band 4 niemals nach unten ins Innere des Zylinderrohres 1 durchhängt und der anstehende Fluiddruck das trapezförmige Band 4 von der Innenseite des Zylinderrohres her in den Schlitz 3 hineindrückt, um den Schlitz 3 sicher abzudichten.In the rodless cylinder constructed in the manner described above, a pressure medium line serving the compressed air supply is connected to a connection opening formed in the cylinder head 2 and serving the compressed air supply, and an object to be moved is coupled or coupled to the plate 14 arranged on the coupling part 11 protruding from the cylinder tube 1 connected. If pressure medium is then supplied via the connection opening, fluid pressure is applied to the right end of the piston 5 shown in FIG. 1, as a result of which the piston 5 is moved to the left. The trapezoidal band 4 is held by the strip projections 12, 12 clamping within the slot, so that the trapezoidal band 4 never sags down into the inside of the cylinder tube 1 and the fluid pressure that is present traps the trapezoidal band 4 from the inside of the cylinder tube Push slot 3 in to securely seal slot 3.

Innerhalb des Zylinderrohres dichten die Kolbenringe (piston cups) 10 die Begrenzung zwischen dem Kolben 5, der Innenoberfläche des Zylinderrohres 1 und der Unterseite des trapezförmigen Bandes 4 ab. Im allgemeinen wird der obere Abschnitt des Kolbenringes 10 gegen die Unterseite des trapezförmigen Bandes 4 gedrückt und dadurch deformiert, wodurch in der Nähe der beiden Seitenränder der Unterseite des trapezförmigen Bandes 4 leicht ein Zwischenraum oder Spalt entsteht, d.h., in einem äußeren Randbereich der äußeren Lippe 10b wird selbige von einem gebogenen Abschnitt zu einem flachem Abschnitt umgelegt. In der vorliegenden Erfindung ist dieser Bereich jedoch durch die Rippen 10c verstärkt, um das Nach-Innen-Neigen der äußeren Lippe 10b zu verhindern, wodurch der Genzbereich zwischen der äußeren Lippe 10b im Bereich beider Längsseiten der Unterseite des trapezförmigen Bandes 4 und der Innenoberfläche des Zylinderrohres 1 vorteilhaft abgedichtet wird.Inside the cylinder tube, the piston cups 10 seal the boundary between the piston 5, the inner surface of the cylinder tube 1 and the underside of the trapezoidal band 4. In general, the upper portion of the piston ring 10 is pressed against the underside of the trapezoidal band 4 and thereby deformed, whereby a gap or gap easily arises near the two side edges of the underside of the trapezoidal band 4, that is, in an outer edge region of the outer lip 10b is folded over from a curved section to a flat section. In the present invention, however, this area is reinforced by the ribs 10c to prevent the outer lip 10b from tilting inward, whereby the border area between the outer lip 10b in the area of both longitudinal sides of the underside of the trapezoidal band 4 and the inner surface of the Cylinder tube 1 is advantageously sealed.

Desweiteren sind die beiden Seitenwände oder Seitenflächen des Schlitzes 3 in konvex gewölbter beziehungsweise gekrümmter Gestaltung ausgeführt und gehen jeweils im Rahmen einer leichten beziehungsweise flachen Kurve in die Innenoberfläche des Zylinderrohres 1 über, so daß selbst dann, wenn der untere scharfkantige Bereich des trapezförmigen Bandes 4 leicht gegenüber der Innenoberfläche des Zylinderrohres nach innen vorsteht - aufgrund von Maßtoleranzen zwischen dem trapezförmigen Band 4 und dem Schlitz 3 -, kein Zwischenraum zwischen der äußeren Lippe 10b des Kolbenringes 10 und der Innenoberfläche des Zylinderrohres 1 erzeugt wird und dadurch die Leckage des Druckmittels minimiert werden kann.Furthermore, the two side walls or side surfaces of the slot 3 are designed in a convexly curved or curved design and each pass in the course of a slight or flat curve into the inner surface of the cylinder tube 1, so that even if the lower sharp-edged region of the trapezoidal band 4 is light protrudes inward from the inner surface of the cylinder tube - due to dimensional tolerances between the trapezoidal band 4 and the Slit 3 -, no space between the outer lip 10b of the piston ring 10 and the inner surface of the cylinder tube 1 is generated and thereby the leakage of the pressure medium can be minimized.

Andererseits verlagern sich in Verbindung mit der Bewegung des Kolbens 5 diejenigen Stellen des trapezförmigen Bandes 4 und des Abdeckbandes 16, die in den Kolben eintreten, nach links, und der verbleibende Abschnitt des trapezförmigen Bandes 4 wird durch den Endblock 7 und den im Zylinder herrschenden Fluiddruck gegen den trapezförmigen beziehungsweise trapezoidalen Querschnitt aufweisenden Schlitz gedrückt und in diesen hineingepreßt, während das Abdeckband 16 durch den Schmutz-Abstreifer 15 nach unten und in den oberen Abschnitt des Schlitzes 3 hineingedrückt wird, wodurch der Schlitz 3 zum einen durch das Abdeckband 16 gegenüber der Außenseite verschmutzungsgesichert und zum anderen durch das trapezoidale Band 4 gegenüber der Innenseite vorteilhaft abgedichtet ist.On the other hand, in connection with the movement of the piston 5, those points of the trapezoidal band 4 and the cover band 16 which enter the piston shift to the left, and the remaining section of the trapezoidal band 4 is affected by the end block 7 and the fluid pressure prevailing in the cylinder pressed against the trapezoidal or trapezoidal cross-section and pressed into it, while the cover strip 16 is pressed down by the dirt wiper 15 and into the upper section of the slot 3, whereby the slot 3 on the one hand through the cover strip 16 towards the outside is secured against contamination and, on the other hand, is advantageously sealed off from the inside by the trapezoidal band 4.

Das trapezförmige Band 4 hat einen im wesentlichen trapezförmigen Querschnitt, worauf seine Benennung beruht, so daß sich die auf das trapezförmige Band 4 einwirkende Druckkraft um so weiter erhöht, je höher der innerhalb des Zylinders herrschende Druck ist, wodurch der vorteilhafte Abdichteffekt erzielt wird. Überdies ist das trapezförmige Band 4 kaum der Betätigungskraft des Kolbens 5 ausgesetzt, so daß es sich niemals ausdehnt und zusammenzieht, weshalb aus einer eventuellen Ausdehnung und Kontraktion des trapezförmigen Bandes 4 keine schädigenden Auswirkungen hergeleitet werden.The trapezoidal band 4 has a substantially trapezoidal cross-section, on which its name is based, so that the pressure force acting on the trapezoidal band 4 increases the higher the pressure prevailing within the cylinder, whereby the advantageous sealing effect is achieved. In addition, the trapezoidal band 4 is hardly exposed to the actuating force of the piston 5, so that it never expands and contracts, which is why no harmful effects are derived from a possible expansion and contraction of the trapezoidal band 4.

Druckluft ist besonders geeignet als Druckquelle für den kolbenstangenlosen Zylinder der vorliegenden Erfindung. Allerdings kann dieser kolbenstangenlose Zylinder auch unter niedrigem hydraulischem Druck betrieben werden.Compressed air is particularly suitable as a pressure source for the rodless cylinder of the present invention. However, this rodless cylinder can also be operated under low hydraulic pressure.

Wie oben beschrieben worden ist, sind bei dem kolbenstangenlosen Zylinder gemäß der vorliegenden Erfindung die beiden Seitenwände des annähernd trapezförmigem Querschnitt aufweisenden Schlitzes in konvex gekrümmter Konstellation geformt und die beiden Seitenwände des Schlitzes stehen mit der inneren Umfangsfläche des Zylinderrohres unter Bildung einer sanften Krümmung oder Kurve bzw. Rundung in Verbindung, was sogar dann, wenn das trapezförmige Band wegen Maßabweichungen seinerseits und/oder des Schlitzes oder wegen des Eindringens von Schmutz nicht korrekt in den Schlitz eingepaßt ist und deshalb der untere eckige Abschnitt des trapezförmigen Bandes leicht über die Innenoberfläche des Zylinderrohres nach innen vorsteht, kein Spalt oder Zwischenraum zwischen der äußeren Lippe des Kolbenringes und der Innenoberfläche des Zylinderrohres entsteht, so daß die Leckage von Druckmittel aus dem Zylinderrohr reduziert wird.As described above, in the rodless cylinder according to the present invention, the two side walls of the approximately trapezoidal cross-sectional slit are formed in a convexly curved configuration, and the two side walls of the slit are in contact with the inner peripheral surface of the cylinder tube to form a gentle curve or curve Rounding in connection, even if the trapezoidal band is not correctly fitted into the slot due to dimensional deviations on its part and / or the slot or due to the penetration of dirt, and therefore the lower angular section of the trapezoidal band slightly behind the inner surface of the cylinder tube protrudes inside, there is no gap or space between the outer lip of the piston ring and the inner surface of the cylinder tube, so that the leakage of pressure medium from the cylinder tube is reduced.

Zusätzlich sind die leistenförmigen Vorsprünge zum zwischen sich Klemmen und Halten des trapezförmigen Bandes an den oberen beziehungsweise radial äußeren Abschnitten der beiden Seitenwände des im wesentlichen trapezförmigen Querschnitt aufweisenden Schlitzes angeformt, so daß derjenige Abschnitt des trapezförmigen Bandes, der außerhalb des Kolbens zu liegen kommt, innerhalb des Zylinderrohres zwischen den Vorsprüngen geklemmt und korrekt innerhalb des Schlitzes gehalten wird. Auf diese Weise kann das Durchhängen des Bandes ins Innere des Zylinderrohres verhindert und die Leckage von Druckmittel durch den Schlitz hindurch reduziert werden.In addition, the strip-shaped projections are between clamping and holding the trapezoidal band on the upper or radially outer portions of the two side walls of the substantially trapezoidal cross-section slot, so that the portion of the trapezoidal band that comes to lie outside the piston is clamped inside the cylinder tube between the projections and is correctly held within the slot. In this way the sagging of the band inside the cylinder tube can be prevented and the leakage of pressure medium through the slot can be reduced.

Durch die konvexe Schlitzwandgestaltung - die Schlitzwände sind zweckmäßigerweise von den den Schlitz längsseits begrenzenden Abschnitten des Zylinderrohres gebildet - ergibt sich vorzugsweise eine derartige Gestaltung, daß sich die Schlitzbreite von einem radial mittleren Schlitzbereich aus in Richtung zum Innenraum des Zylinderrohres hin verbreitert, so wie dies in der Figur 4 zum Ausdruck kommt. Die Konturierung der Seitenwände beziehungsweise Seitenflächen des Schlitzes 3 erfolgt hierbei zweckmäßigerweise zumindest im wesentlichen komplementär zur Konturierung der konkaven Seitenflächen 4a des trapezförmigen Bandes 4.Due to the convex diaphragm wall design - the diaphragm walls are expediently formed by the sections of the cylinder tube which delimit the slot along the longitudinal side - there is preferably such a configuration that the slot width widens from a radially central slot area towards the interior of the cylinder tube, as shown in FIG the figure 4 is expressed. The contouring of the side walls or side surfaces of the slot 3 is expediently at least substantially complementary to the contouring of the concave side surfaces 4a of the trapezoidal band 4.

Sofern in der vorliegenden Figurenbeschreibung auf Ortsangaben wie "oben" oder "unten" Bezug genommen wird, so bezieht sich dies auf eine Darstellung gemäß der Figur 1, bei der der Schlitz 3 des Zylinderrohres an der Oberseite des kolbenstangenlosen Zylinders zu liegen kommt.If reference is made to location information such as "above" or "below" in the present description of the figures, this refers to a representation according to FIG. 1 in which the slot 3 of the cylinder tube comes to rest on the top of the rodless cylinder.

Die vorliegende Erfindung ist zwar unter Bezugnahme auf ein bevorzugtes Ausführungsbeispiel beschrieben worden. Sie ist jedoch nicht darauf beschränkt, sondern kann in vielerlei Weise variiert und modifiziert werden, ohne vom Inhalt der vorliegenden Erfindung abzuweichen.The present invention has been described with reference to a preferred embodiment. However, it is not limited thereto, but can be varied and modified in many ways without departing from the content of the present invention.

Claims (4)

  1. Rodless cylinder, with a cylinder barrel (1) which has a longitudinal slot (3) with an essentially trapezoidal cross-section, with a strip (4), in cross-section at least mainly trapezoidal, fixed by its two ends to the end areas of the cylinder barrel (1), resting in the slot (3) and passing slideably through a piston (5) mounted in the cylinder barrel (1), and with one or more piston rings (10) located in the outer peripheral area of the piston (5), having an outer lip (10b) in contact with the underside of the strip (4), an inner lip (10a) and ribs (10c) in the area of the side edges of the underside of the strip (4) between the outer and inner lips (10b,10a), characterised in that the two sides of the slot (3) with its essentially trapezoidal cross-section have a convex curved shape in that area intended for sealing contact with the strip (4), and that the convex curved sides of the slot (3) each merge within a gentle or flowing curve into the inner surface of the cylinder barrel (1).
  2. Rodless cylinder according to claim 1, characterised in that projections (12) are provided on the sides of the slot (3) which, with their radially outwards section clamp the inwards-pressed strip (4) between them under the action of fluidic pressure.
  3. Rodless cylinder according to claims 1 or 2, characterised in that projections (13) are provided on the sides of the slot (3), these projections clamping a covering strip (16) located on the outside of the slot (3).
  4. Rodless cylinder according to claims 2 or 3, characterised in that the projections (12,13) are in the form of rails, strips or ribs.
EP91115723A 1991-02-19 1991-09-17 Rodless actuator Expired - Lifetime EP0499687B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP3023639A JPH04266606A (en) 1991-02-19 1991-02-19 Rodless cylinder
JP23639/91 1991-02-19

Publications (2)

Publication Number Publication Date
EP0499687A1 EP0499687A1 (en) 1992-08-26
EP0499687B1 true EP0499687B1 (en) 1995-02-22

Family

ID=12116144

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91115723A Expired - Lifetime EP0499687B1 (en) 1991-02-19 1991-09-17 Rodless actuator

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US (1) US5531151A (en)
EP (1) EP0499687B1 (en)
JP (1) JPH04266606A (en)
DE (1) DE59104706D1 (en)
DK (1) DK0499687T3 (en)
ES (1) ES2068450T3 (en)
GR (1) GR3015872T3 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2935321B2 (en) * 1992-12-24 1999-08-16 日産自動車株式会社 Slide transport device
AT401554B (en) * 1994-05-18 1996-10-25 Hygrama Ag PISTONLESS PRESSURE CYLINDER
DE9410393U1 (en) * 1994-06-28 1994-08-18 Festo Kg, 73734 Esslingen linear actuator
JPH08261209A (en) * 1995-03-23 1996-10-08 Pabotsuto Giken:Kk Slit type rodless cylinder
US6257123B1 (en) 1997-10-24 2001-07-10 Phd, Inc. Rodless slides
US5988042A (en) * 1997-10-24 1999-11-23 Phd, Inc. Rodless cylinder with internal bearings
SE520017C2 (en) * 1997-10-31 2003-05-06 Mecman Ab Rexroth Pressure fluid cylinder
US5996469A (en) * 1998-04-07 1999-12-07 Greenco Manufacturing Corporation Rodless power cylinder
SE512033C2 (en) * 1998-05-12 2000-01-17 Mecman Ab Rexroth Piston seal and wear cylinder with a piston provided with two such seals
US6336393B1 (en) 1998-07-01 2002-01-08 Parker-Hannifin Corporation Rodless pneumatic cylinder
US6857780B2 (en) * 2002-11-15 2005-02-22 Phd, Inc. Rodless slide assembly
DE102004003620B4 (en) * 2004-01-16 2011-12-08 Airtec Pneumatic Gmbh Seal with rodless cylinders
WO2008116487A1 (en) * 2007-03-28 2008-10-02 Norgren Gmbh Piston support portion for a piston assembly of a rodless cylinder

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GB470088A (en) * 1936-02-03 1937-08-03 Merz Franz Improvements in fluid-operated piston apparatus
DE1475809A1 (en) * 1964-09-04 1969-03-13 Hermann Rasper Device for moving a piston carrying an assembly into any desired position along a tubular cylinder
CH436617A (en) * 1965-04-20 1967-05-31 Roethlin Albert Hydraulic or pneumatic conveying device
US4373427A (en) * 1980-01-31 1983-02-15 Tol-O-Matic, Inc. Fluid pressure cylinder
DE3429783A1 (en) * 1984-08-13 1986-02-20 Herion-Werke Kg, 7012 Fellbach PISTONLESS CYLINDER
JPS62184208A (en) * 1986-02-07 1987-08-12 Akio Matsui Rodless cylinder
DE3631514A1 (en) * 1986-09-17 1988-03-24 Proma Prod & Marketing Gmbh PRESSURE CYLINDER
US4829881A (en) * 1987-03-12 1989-05-16 Ckd Corporation Rod-less cylinder
IT1217812B (en) * 1988-06-08 1990-03-30 Univers S P A Seal for rodless pneumatic cylinder

Also Published As

Publication number Publication date
US5531151A (en) 1996-07-02
ES2068450T3 (en) 1995-04-16
GR3015872T3 (en) 1995-07-31
EP0499687A1 (en) 1992-08-26
JPH04266606A (en) 1992-09-22
DK0499687T3 (en) 1995-06-19
DE59104706D1 (en) 1995-03-30

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