EP0979357B1 - Hydrostatic displacement drive for lifting and lowering and holding loads, in particular for lifts - Google Patents

Hydrostatic displacement drive for lifting and lowering and holding loads, in particular for lifts Download PDF

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Publication number
EP0979357B1
EP0979357B1 EP98914771A EP98914771A EP0979357B1 EP 0979357 B1 EP0979357 B1 EP 0979357B1 EP 98914771 A EP98914771 A EP 98914771A EP 98914771 A EP98914771 A EP 98914771A EP 0979357 B1 EP0979357 B1 EP 0979357B1
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EP
European Patent Office
Prior art keywords
pressure
working cylinder
lifting piston
lifting
piston
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EP98914771A
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German (de)
French (fr)
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EP0979357A2 (en
Inventor
Sead Veletovac
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Wittur AG
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Wittur AG
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
    • B66B9/00—Kinds or types of lifts in, or associated with, buildings or other structures
    • B66B9/04—Kinds or types of lifts in, or associated with, buildings or other structures actuated pneumatically or hydraulically

Definitions

  • the invention relates to a hydrostatic drive for lifting and Lowering and holding loads, especially for elevators, with one connected to a pressure medium source, one working cylinder, a in the working cylinder sealingly guided piston and one in Working cylinder arranged guide rod that into the interior of the Piston protrudes, which surrounds the guide rod sealingly, the end of the reciprocating piston projecting into the pressure chamber forms annular, pressurized face.
  • Such a drive is known from AT-PS 385 018, which is used for lifting and lowering loads over great heights.
  • This Drive is supposed to be that the end protruding into the working cylinder of the reciprocating piston sealingly on the guide rod, security can be improved against buckling. Otherwise because of the kink resistance necessary large diameter of the massive piston is now by the annular face that replaces the work surface of the Reciprocating piston forms. The hollow because of the annular face The piston is not pressurized on the inside.
  • Known drive is the total lifting power with each lifting operation solely from that located in the pressure chamber of the working cylinder applied the annular end face pressure medium, the is fed to the working cylinder with variable pressure. The whole Lifting force acts here over the entire length of the lifting piston. To the To ensure kink resistance, the wall thickness of the piston must be dimensioned accordingly large.
  • One disadvantage is that the working surface of the piston increases with increasing length, the flow rate increases and requires a larger pump.
  • the invention has for its object a known hydrostatic drive in terms of buckling safety improve so that longer lengths are possible.
  • a hollow reciprocating piston 1 which at its upper end by a End wall 2 is closed.
  • the lower end 3 of the vertical arranged piston 1 is somewhat thickened on its inside and on a guide rod 15 slidably guided with its lower end 16 in a base plate 20 of a working cylinder 10 is attached.
  • a mechanical seal 4 is embedded, so that it acts as a pressure chamber acting interior of the piston 1 tightly from the inside of the working cylinder 10 is separated.
  • the upper end 11 of the working cylinder 10 is also thickened on the inside and with a mechanical seal 12 provided that abuts the outside of the reciprocating piston 1.
  • a pressure medium line 23 is connected to the outside is that comes from a pressure medium source 30, the pressure medium with in supplies essential constant pressure P2.
  • the bore 21 opens into the inside of the working cylinder 10, which delimits a pressure chamber 13.
  • a further bore 22 is provided in the base plate 20, on which outside a pressure medium line 24 is connected by a second pressure medium source 40 comes in the form of a feed pump that Pressure medium with variable pressure P1 delivers.
  • the top of the Bore 22 opens into one in the guide rod 15 axial channel 17 which at its upper end 18 in the pressure chamber 7 of the Reciprocating piston 1 opens.
  • the pressure source 30 consists of an electric motor 31 driven feed pump 32, the pressure medium from a tank 39th sucks and via the pressure medium line 23 into the pressure chamber 13 of the Working cylinder 10 promotes.
  • a valve 33 which is a switching or proportional directional control valve can be that in the position shown the pressure medium flow isolates and in another position pressure medium to the pressure chamber 13 can flow through.
  • an overflow line 35 branches off from line 34 Pressure relief valve 36, which leads back into the tank 39.
  • the Feed pump 42 is also driven by an electric motor 41 and sucks pressure medium from a tank 39.
  • her line 22 In her line 22 is a valve 43 arranged which is a switching or Proportionalwegventil can be, analog to the valve 33 two Can take end positions.
  • An overflow line 45 with a pressure relief valve 45 is similar to the feed pump 32 in the Feed pump 42 available.
  • the feed pump 42 also supplies pressure medium a variable pressure P1 in the pressure chamber 7 of the reciprocating piston 1.
  • Spacer ring 25 attached, the flexible tension elements 26 to Example wire ropes, suspended at the lower end 3 of the reciprocating piston 1 is.
  • a further spacer ring 25 'as required is the same attached below the spacer ring 25, which in the drawn position of the reciprocating piston 1 still on the base plate 20th rests.
  • the spacer rings 25 and 25 ' serve to buckle the To prevent guide rod 15. You move smoothly with it Reciprocating piston 1 up and down, being in the lowest position of the Piston of the spacer ring 25 to lie on the spacer ring 25 ' can come.
  • the pressure medium can freely in the Spread out entire interior 13.
  • the piston 1 is over his Length distributed with one or more spacer rings 27 as required provided, when moving the piston on the guide rod 15th slide and serve as protection against buckling of the reciprocating piston 1.
  • the pressure medium with the pressure P2 in the pressure chamber 13 of the working cylinder 10 acts on an annular end face 5 at the lower end 3 of the Reciprocating piston 1.
  • the end face 5 forms an annular work surface A2, as shown on the right in FIG. 1.
  • the interior of the Reciprocating piston 1 forms the further pressure chamber 7, in which the pressure medium the pressure medium source 40 acts with the variable pressure P1.
  • a further work surface 6 the Size of the inner diameter of the working surface A2 is determined.
  • she is shown separately in FIG. 1 on the right as circular area A1.
  • a throttle rod 60 is attached, which is coaxial with Channel 17 is arranged in the guide rod 15.
  • the lower half the throttle rod 60 is slightly tapered downwards educated.
  • the pressure medium with the pressure P2 of substantially constant Size creates a constant on the work surface A2 Lifting force that is approximately so large that, depending on the need, e.g. about 90% the mass of a car on the upper end of the piston 1 supported elevator corresponds. This part of the mass is in Fig. 1st indicated by arrow F2. Thus, part of the car mass balanced and is in balance with the lifting force.
  • FIG. 2 is that of the reciprocating piston 1, the working cylinder 10 and the guide rod 15 existing drive constructed the same as in Fig. 1.
  • a vertical additional cylinder 50 is provided, in which a Additional piston 55 is guided sealingly.
  • a Counterweight 57 attached on the additional piston 55 is a Counterweight 57 attached; which is about 90% of the mass of that on the Reciprocating piston 1 supported car 62 corresponds.
  • the crowd is with M denotes.
  • the underside of the vertically arranged auxiliary piston 55 forms a third work surface 56, the size of which is to the left of the Additional piston 55 shown separately in Fig. 2 and designated A3 is.
  • Feed pump 42 connected, the pressure medium with variable pressure supplies.
  • the feed pump 42 is connected via a line 64 to the Pressure medium line 23 connected.
  • Line 64 contains a valve 63, which corresponds to the structure of the valve 43.
  • the tank 39 for the pressure medium be dimensioned much smaller, since a large amount of the Pressure medium is received by the additional cylinder 50.
  • there depending on the size ratio of the third work surface A3 to the annular work surface A2 Reduction of drive power can reach up to 50%.
  • Another The drive power is reduced by the fact that in 2 the suction side of the feed pump 42 via the Line 64 is connected to the pressure medium line 23, so that the Feed pump 42 is fed with pressure medium of constant pressure P2 and only have to generate the pressure increase from P2 to P1.
  • the Working cylinder 10 in its upper section 10 ' Reduced outside diameter and has a stepped transition to the larger outside diameter in the lower section 10 ''.
  • the upper reduced section 10 ' is from an auxiliary cylinder 70 surrounded in a sealing manner, on the outside of which the counterweight 57 ' is appropriate.
  • the upper end 71 of the additional cylinder 70 is against the upper reduced section 10 'of the working cylinder 10 down thickened and lies on the upper section via a mechanical seal 72 10 'of the working cylinder 10.
  • a mechanical seal 74 is provided, which on lower thickened portion 10 '' of the working cylinder 10 abuts.
  • a plurality of through holes 76 provided that the pressure chamber 13 of the working cylinder 10 with a Connect pressure chamber 75, the upper end face 77 of which has an annular shape and the inner diameter of the auxiliary cylinder 70 and the reduced one Outside diameter of the cylinder section 10 'is limited.
  • the same diameter also limit an annular work surface A3, shown on the right in Fig. 3, the thickened upper end of the Additional cylinder 70 is formed.
  • the feed pump 42 is in the bottom plate 20 'of the Working cylinder 10 installed. It is on the suction side Bore 23 and connected with its pressure side to the bore 21. There are one on the suction side and one on the pressure side of the feed pump Valve 43 or 63 provided as a switching or proportional valve trained, arranged to open and close the concerned Management.
  • FIG. 4 is compared to that according to FIG. 3 modified in that the working cylinder 110 in two axially sections 110 'and 110' 'which are displaceable relative to one another, the upper portion 110 'having a shape similar to that Additional cylinder 70 in FIG. 3.
  • the upper cylinder section 110 'is on its upper end 111 is also thickened and with a Mechanical seal 112 provided. It slides on with this end Reciprocating piston 1.
  • the lower end 111 of the cylinder section 110 ' is sealing against the fixed lower section 110 "of the Working cylinder 110 guided, for which purpose the mechanical seal 112 in thickened end 111 of the upper cylinder portion 110 'is provided is.
  • a pressure chamber 75 ' included that is delimited at the upper end by the end wall 11 ' that forms the annular work surface A3.
  • the counterweight 57' ' is attached on the outside of the upper cylinder section 110 '.
  • the feed pump 42 is of the same design and into the Base plate 20 "installed as in the example according to FIG. 3. Accordingly, the mode of operation is the same as that of FIG. 3 described, i.e. the upper one presses when lifting the load Cylinder section 110 'under the influence of the counterweight 57 " Pressure medium with the constant pressure P2 in the pressure chamber 13 of the Working cylinder 110, whereby the reciprocating piston 1 is raised.
  • pressure medium passes from the pressure chamber 13 via the Bore 23 to the feed pump 42, which it with the variable pressure P1 in supplies the further pressure chamber 7 of the reciprocating piston 1.
  • This pressure medium affects the further work surface A1 and supports the Upward movement of the reciprocating piston.
  • the pressure medium with a substantially constant pressure supplies a bladder accumulator or a piston accumulator can be used. Also connected to the pressure rooms 7 and 13 Pressure sources are interchanged, i.e. that the pressure chamber pressure medium with constant pressure and the pressure chamber 13 pressure medium with variable Pressure is supplied.
  • the drive described is not only for Lifts can be used; e.g. also for moving up and down Carriage on machine tools, lifting platform for cranes, forklifts, Lifting platforms, active car or truck shock absorbers, etc. are used become.
  • one or two can be used as required or more than two spacers 25 and 25 'and 27 may be provided, then with a corresponding mutual distance in the reciprocating piston 1 attached or attached to each other via ropes 26.
  • the Counterweight 57 can be attached directly or with ropes to the Additional pistons or additional cylinders attached to the roller must be suspended, which halves the mass of the counterweight.
  • the electric motor 41 can be connected to a frequency converter and this to an electronic Control card connected, which then control signals to the Frequency converter and the valves supplies.
  • the valves are as Switching or proportional directional valves provided, which also with pulse-modulated signals can be controlled. Drives can only one valve can be installed in the pressure medium line 23 or 24.
  • the filters can in the two pressure medium lines 23 and 24, or can only be installed in a pressure medium line 23 or 24.

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  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Structural Engineering (AREA)
  • Actuator (AREA)
  • Types And Forms Of Lifts (AREA)
  • Forklifts And Lifting Vehicles (AREA)
  • Details Of Reciprocating Pumps (AREA)
  • Load-Engaging Elements For Cranes (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

The hydraulic or pneumatic drive for lifting and lowering loads, in particular for lifts, has a working cylinder (11) forming a pressure chamber (14) connected to a pressure fluid source (39) and subjected to a pressure fluid. It also has a lifting piston (1) tightly guided in the working cylinder and a guide rod (15) arranged in the working cylinder. The guide rod (15) projects into the interior of the lifting piston (1) which tightly encloses the guide rod (15). The end (4) of the lifting piston (1) which projects into the pressure chamber (14) forms an annular face (5) which is subjected to pressure fluid. The interior of the lifting piston (1) forms an additional pressure chamber (7) subjected to pressure fluid and which is connected to its own pressure fluid source (40). The pressure fluid source connected to the working cylinder (11) delivers pressure fluid at a substantially constant pressure, whereas the pressure fluid source (40) connected to the additional pressure chamber (7) delivers pressure fluid at a variable pressure. The additional pressure chamber (7), subjected to pressure fluid, subdivides the total force needed to lift a load into two partial forces, one of which acts upon the annular face and the other in the interior of the lifting piston, close under the load. In this way, the partial force acting upon the entire length of the lifting piston and subjecting the piston to buckling is substantially reduced. It is thus possible to reduce the amount of material required without affecting buckling resistance.

Description

Die Erfindung betrifft einen hydrostatischen Antrieb zum Heben und Senken und zum Halten von Lasten, insbesondere für Aufzüge, mit einem an eine Druckmittelquelle angeschlossenen, einen druckmittelbeaufschlagten Druckraum bildenden Arbeitszylinder, einem im Arbeitszylinder dichtend geführten Hubkolben und einer im Arbeitszylinder angeordneten Führungsstange, die in das Innere des Hubkolbens ragt, der die Führungsstange dichtend umfasst, wobei das in den Druckraum ragende Ende des Hubkolbens eine ringförmige, druckmittelbeaufschlagte Stirnfläche bildet.The invention relates to a hydrostatic drive for lifting and Lowering and holding loads, especially for elevators, with one connected to a pressure medium source, one working cylinder, a in the working cylinder sealingly guided piston and one in Working cylinder arranged guide rod that into the interior of the Piston protrudes, which surrounds the guide rod sealingly, the end of the reciprocating piston projecting into the pressure chamber forms annular, pressurized face.

Ein solcher Antrieb ist aus der AT-PS 385 018 bekannt, der zum Heben und Senken von Lasten über grosse Höhen bestimmt ist. Bei diesem Antrieb soll dadurch, dass das in den Arbeitszylinder ragende Ende des Hubkolbens dichtend an der Führungsstange gleitet, die Sicherheit gegen Knicken verbessert werden. Der sonst wegen der Knicksicherheit notwendige grosse Durchmesser des massiven Hubkolbens wird nun durch die ringförmige Stirnfläche ersetzt, die die Arbeitsfläche des Hubkolbens bildet. Der wegen der ringförmigen Stirnfläche hohle Hubkolben ist innen nicht vom Druckmittel beaufschlagt. Bei dem bekannten Antrieb wird bei jedem Hebevorgang die gesamte Hubkraft allein von dem im Druckraum des Arbeitszylinders befindlichen, auf die ringförmige Stirnfläche wirkenden Druckmittel aufgebracht, das mit variablem Druck dem Arbeitszylinder zugeführt wird. Die gesamte Hubkraft wirkt hier also über die ganze Länge des Hubkolbens. Um die Knicksicherheit zu gewährleisten, muss die Wanddicke des Hubkolbens entsprechend gross dimensioniert werden. Ein Nachteil besteht darin, dass mit wachsender Länge des Hubkolbens dessen Arbeitsfläche steigt, die Durchflussmenge zunimmt und eine grössere Pumpe erfordert. Such a drive is known from AT-PS 385 018, which is used for lifting and lowering loads over great heights. With this Drive is supposed to be that the end protruding into the working cylinder of the reciprocating piston sealingly on the guide rod, security can be improved against buckling. Otherwise because of the kink resistance necessary large diameter of the massive piston is now by the annular face that replaces the work surface of the Reciprocating piston forms. The hollow because of the annular face The piston is not pressurized on the inside. In which Known drive is the total lifting power with each lifting operation solely from that located in the pressure chamber of the working cylinder applied the annular end face pressure medium, the is fed to the working cylinder with variable pressure. The whole Lifting force acts here over the entire length of the lifting piston. To the To ensure kink resistance, the wall thickness of the piston must be dimensioned accordingly large. One disadvantage is that the working surface of the piston increases with increasing length, the flow rate increases and requires a larger pump.

in US-A-2,269,786 ist ein hydrostatischer Antrieb beschrieben, bei dem im Arbeitszylinder für den Antrieb der Aufzugskabine neben dem die Führungsstange umgebenden Druckraum ein zweiter Druckraum vorhanden ist, der die Führungsstange durchdringt. Die Führungsstange hat also im Gegensatz zu AT-PS 385 018 keinen kreisförmigen Querschnitt, sondern einen ringförmigen Querschnitt. Dadurch, daß sich im Innenraum der Führungsstange ein Druckraum befindet, ist eine höhere Knicksicherheit der Führungsstange gewährleistet, obwohl der Materialbedarf für die Führungsstange deutlich reduziert ist, was gleichzeitig eine bedeutende Gewichtseinsparung mit sich bringt. Hydraulisch befindet sich zwischen den beiden Druckräume eine in ihrer Drehrichtung umschaltbare Pumpe, die Hydraulikflüssigkeit zwischen den beiden Druckräumen umpumpen kann. Einer der beiden Druckräume des Antriebs steht in Verbindung mit einem zweiten hydraulischen Antrieb, der ein Gewicht trägt, das als Gegengewicht zur Aufzugskabine wirkt. in US-A-2,269,786 a hydrostatic drive is described in that in the working cylinder for the drive of the elevator car next to the a second pressure chamber surrounding the guide rod is present that penetrates the guide rod. The guide rod in contrast to AT-PS 385 018 it does not have a circular one Cross section, but an annular cross section. As a result of that there is a pressure chamber in the interior of the guide rod ensures higher kink resistance of the guide rod, although the Material requirements for the guide rod is significantly reduced, what at the same time brings significant weight savings. Hydraulically there is an in between the two pressure chambers their direction of rotation switchable pump, the hydraulic fluid can pump between the two pressure chambers. One of both The pressure chambers of the drive are connected to a second one hydraulic drive that carries a weight that acts as a counterweight to the elevator car.

Der Erfindung liegt die Aufgabe zugrunde, einen bekannten hydrostatischen Antrieb hinsichtlich der Knicksicherheit weiter zu verbessern, so dass auch grössere Baulängen möglich werden.The invention has for its object a known hydrostatic drive in terms of buckling safety improve so that longer lengths are possible.

Diese Aufgabe wird durch die kennzeichnenden Merkmale des Anspruchs 1 gelöst. Vorteilhafte Ausgestaltungen sind Gegenstand abhängiger Ansprüche. This object is achieved by the characterizing features of claim 1 solved. Advantageous refinements are subject-dependent Expectations.

Einige-Ausführungsbeispiele und weitere Einzelheiten der Erfindung werden in der folgenden Beschreibung anhand der Zeichnung näher erläutert. Es zeigen:

Fig. 1
einen Längsschnitt durch einen hydrostatischen Antrieb mit zwei Druckräumen, und
Fig. 2 bis 4
je einen Längsschnitt durch einen hydrostatischen Antrieb, wobei jeweils die Druckmittelquelle, die Druckmittel mit im wesentlichen konstanten Druck liefert, durch ein Gegengewicht ersetzt ist, das auf eine besondere Kolben-/Zylinderanordnung wirkt.
Some exemplary embodiments and further details of the invention are explained in more detail in the following description with reference to the drawing. Show it:
Fig. 1
a longitudinal section through a hydrostatic drive with two pressure chambers, and
2 to 4
each a longitudinal section through a hydrostatic drive, the pressure medium source, which supplies pressure medium with essentially constant pressure, being replaced by a counterweight, which acts on a special piston / cylinder arrangement.

Gemäss Fig. 1 weist der hydrostatische Antrieb wie bei US-A-2,269,786 einen hohlen Hubkolben 1 auf, der an seinem oberen Ende durch eine Stirnwand 2 verschlossen ist. Das untere Ende 3 des vertikal angeordneten Hubkolbens 1 ist auf seiner Innenseite etwas verdickt und auf einer Führungsstange 15 gleitend geführt, die mit ihrem unteren Ende 16 in einer Bodenplatte 20 eines Arbeitszylinders 10 befestigt ist. Im unteren Ende 3 des Hubkolbens 1 ist eine Gleitringdichtung 4 eingelassen, sodass der als Druckraum wirkende Innenraum des Hubkolbens 1 dicht vom Innern des Arbeitszylinders 10 getrennt ist. Das obere Ende 11 des Arbeitszylinders 10 ist ebenfalls auf der Innenseite verdickt und mit einer Gleitringdichtung 12 versehen, die an der Aussenseite des Hubkolbens 1 anliegt. Auf diese weise ist der Hubkolben 1 im Arbeitszylinder 10 dichtend geführt. In der Bodenplatte 20 des Arbeitaszylinders 10 ist eine Bohrung 21 vorgesehen, an die aussen eine Druckmittelleitung 23 angeschlossen ist, die von einer Druckmittelquelle 30 kommt, die Druckmittel mit im wesentlichen Konstanten Druck P2 liefert. Die Bohrung 21 mündet in das Innere des Arbeitszylinders 10, der einen Druckraum 13 begrenzt. In der Bodenplatte 20 ist eine weitere Bohrung 22 vorgesehen, an der aussen eine Druckmittelleitung 24 angeschlossen ist, die von einer zweiten Druckmittelquelle 40 in Form einer Förderpumpe kommt, die Druckmittel mit variablem Druck P1 liefert. Das obere Ende der Bohrung 22 mündet in einen in der Führungsstange 15 angebrachten axialen Kanal 17, der an seinem oberen Ende 18 in den Druckraum 7 des Hubkolbens 1 mündet.1 has the hydrostatic drive as in US-A-2,269,786 a hollow reciprocating piston 1, which at its upper end by a End wall 2 is closed. The lower end 3 of the vertical arranged piston 1 is somewhat thickened on its inside and on a guide rod 15 slidably guided with its lower end 16 in a base plate 20 of a working cylinder 10 is attached. In the lower end 3 of the Reciprocating piston 1, a mechanical seal 4 is embedded, so that it acts as a pressure chamber acting interior of the piston 1 tightly from the inside of the working cylinder 10 is separated. The upper end 11 of the working cylinder 10 is also thickened on the inside and with a mechanical seal 12 provided that abuts the outside of the reciprocating piston 1. To this the reciprocating piston 1 is guided sealingly in the working cylinder 10. In the bottom plate 20 of the working cylinder 10 is a bore 21 provided to which a pressure medium line 23 is connected to the outside is that comes from a pressure medium source 30, the pressure medium with in supplies essential constant pressure P2. The bore 21 opens into the inside of the working cylinder 10, which delimits a pressure chamber 13. A further bore 22 is provided in the base plate 20, on which outside a pressure medium line 24 is connected by a second pressure medium source 40 comes in the form of a feed pump that Pressure medium with variable pressure P1 delivers. The top of the Bore 22 opens into one in the guide rod 15 axial channel 17 which at its upper end 18 in the pressure chamber 7 of the Reciprocating piston 1 opens.

Die Druckquelle 30 besteht aus einer von einem Elektromotor 31 angetriebenen Förderpumpe 32, die Druckmittel aus einem Tank 39 ansaugt und über die Druckmittelleitung 23 in den Druckraum 13 des Arbeitszylinders 10 fördert. In der Druckmittelleitung 23 befindet sich ein Ventil 33, welches ein Schalt- oder Proportionalwegventil sein kann, das in der gezeichneten Stellung den Druckmittelfluss absperrt und in einer anderen Stellung Druckmittel zum Druckraum 13 durchströmen lässt. Zwischen der Förderpumpe 32 und dem ventil 33 zweigt von der Leitung 34 eine Ueberströmleitung 35 mit Ueberdruckventil 36 ab, die in den Tank 39 zurückführt. Die Förderpumpe 42 ist ebenfalls von einem Elektromotor 41 angetrieben und saugt Druckmittel aus einem Tank 39 an. In ihrer Leitung 22 ist ein ventil 43 angeordnet, welches ein Schalt- oder Proportionalwegventil sein kann, das analog dem Ventil 33 zwei Endstellungen einnehmen kann. Auch eine Ueberströmleitung 45 mit einem Ueberdruckventil 45 ist analog zur Förderpumpe 32 bei der Förderpumpe 42 vorhanden. Die Förderpumpe 42 liefert Druckmittel mit einem variablen Druck P1 in den Druckraum 7 des Hubkolbens 1.The pressure source 30 consists of an electric motor 31 driven feed pump 32, the pressure medium from a tank 39th sucks and via the pressure medium line 23 into the pressure chamber 13 of the Working cylinder 10 promotes. Located in the pressure medium line 23 there is a valve 33, which is a switching or proportional directional control valve can be that in the position shown the pressure medium flow isolates and in another position pressure medium to the pressure chamber 13 can flow through. Between the feed pump 32 and the valve 33 an overflow line 35 branches off from line 34 Pressure relief valve 36, which leads back into the tank 39. The Feed pump 42 is also driven by an electric motor 41 and sucks pressure medium from a tank 39. In her line 22 is a valve 43 arranged which is a switching or Proportionalwegventil can be, analog to the valve 33 two Can take end positions. An overflow line 45 with a pressure relief valve 45 is similar to the feed pump 32 in the Feed pump 42 available. The feed pump 42 also supplies pressure medium a variable pressure P1 in the pressure chamber 7 of the reciprocating piston 1.

Im Innenraum 13 des Arbeitszylinders 10 ist erfindungsgemäss je nach Bedarf mindestens ein Distanzring 25 angebracht, der über flexible Zugelemente 26, zum Beispiel Drahtseile, am unteren Ende 3 des Hubkolbens 1 aufgehängt ist. Ein je nach Bedarf weiterer Distanzring 25' ist in gleicher weise unterhalb des Distanzringes 25 angebracht, der in der gezeichneten Stellung des Hubkolbens 1 noch auf der Bodenplatte 20 aufliegt. Die Distanzringe 25 und 25' dienen dazu, ein Ausknicken der Führungsstange 15 zu verhindern. Sie bewegen sich gleitend mit dem Hubkolben 1 auf- und abwärts, wobei in der tiefsten Stellung des Hubkolbens der Distanzring 25 auf den Distanzring 25' zu liegen kommen kann. Ueber vorzugsweise axiale Durchbrüche in den Distanzringen 25 und 25' kann das Druckmittel sich ungehindert in den gesamten Innenraum 13 ausbreiten. Auch der Hubkolben 1 ist über seine Länge verteilt mit je nach Bedarf einem oder mehrere Distanzringen 27 versehen, die beim Bewegen des Hubkolbens auf der Führungsstange 15 gleiten und als Schutz gegen Ausknicken des Hubkolbens 1 dienen.According to the invention, there is at least one in the interior 13 of the working cylinder 10 as required Spacer ring 25 attached, the flexible tension elements 26 to Example wire ropes, suspended at the lower end 3 of the reciprocating piston 1 is. A further spacer ring 25 'as required is the same attached below the spacer ring 25, which in the drawn position of the reciprocating piston 1 still on the base plate 20th rests. The spacer rings 25 and 25 'serve to buckle the To prevent guide rod 15. You move smoothly with it Reciprocating piston 1 up and down, being in the lowest position of the Piston of the spacer ring 25 to lie on the spacer ring 25 ' can come. Preferably, axial openings in the Spacer rings 25 and 25 ', the pressure medium can freely in the Spread out entire interior 13. The piston 1 is over his Length distributed with one or more spacer rings 27 as required provided, when moving the piston on the guide rod 15th slide and serve as protection against buckling of the reciprocating piston 1.

Das Druckmittel mit dem Druck P2 im Druckraum 13 des Arbeitszylinders 10 wirkt auf eine ringförmige Stirnfläche 5 am unteren Ende 3 des Hubkolbens 1. Die Stirnfläche 5 bildet eine ringförmige Arbeitsfläche A2, wie sie in Fig. 1 rechts dargestellt ist. Der Innenraum des Hubkolbens 1 bildet den weiteren Druckraum 7, in dem das Druckmittel der Druckmittelquelle 40 mit dem variablen Druck P1 wirkt. An der Stirnwand 2 wird deshalb eine weitere Arbeitsfläche 6 gebildet, deren Grösse vom Innendurchmesser der Arbeitsfläche A2 bestimmt wird. Sie ist in Fig. 1 rechts separat als Kreisfläche A1 dargestellt. In der Stirnwand 2 ist eine Drosselstange 60 befestigt, die koaxial zum Kanal 17 in der Führungsstange 15 angeordnet ist. Die untere Hälfte der Drosselstange 60 ist nach unten leicht kegelig verjüngend ausgebildet. Sie bildet beim Abwärtsbewegen des Hubkolbens 1 auf dessen letzten Bewegungsabschnitt von etwa 1 m Länge beim Eintauchen in den Kanal 17 mit diesem zusammen eine Drosselstelle. Dadurch wird die Abwärtsbewegung des Hubkolbens gedämpft. Am Ende der Bohrungen 21 und 23 sind jeweils ein Rohrbruchsicherheitsventil 68 und 69 vorgesehen, welche bei einem eventuell auftretendem Bruch der DruckmittelLeitungen 23 und 24 als Drossel dienen.The pressure medium with the pressure P2 in the pressure chamber 13 of the working cylinder 10 acts on an annular end face 5 at the lower end 3 of the Reciprocating piston 1. The end face 5 forms an annular work surface A2, as shown on the right in FIG. 1. The interior of the Reciprocating piston 1 forms the further pressure chamber 7, in which the pressure medium the pressure medium source 40 acts with the variable pressure P1. At the End wall 2 is therefore formed a further work surface 6, the Size of the inner diameter of the working surface A2 is determined. she is shown separately in FIG. 1 on the right as circular area A1. In the End wall 2, a throttle rod 60 is attached, which is coaxial with Channel 17 is arranged in the guide rod 15. The lower half the throttle rod 60 is slightly tapered downwards educated. It forms when the reciprocating piston 1 moves downward the last movement section of about 1 m in length when immersed in the channel 17 together with this a throttle point. This will damped the downward movement of the reciprocating piston. At the end of holes 21 and 23 are a pipe rupture safety valve 68 and 69, respectively provided, which in the event of a possible breakage of the pressure medium lines 23 and 24 serve as a throttle.

Das Druckmittel mit dem Druck P2 von in wesentlichen konstanter Grösse erzeugt stetig auf der Arbeitsfläche A2 eine konstante Hubkraft, die etwa so gross ist, dass je nach Bedarf, z.B. etwa 90 % der Masse eines Fahrkorbes eines auf dem oberen Ende des Hubkolbens 1 abgestützten Aufzuges entspricht. Dieser Teil der Masse ist in Fig. 1 mit dem Pfeil F2 bezeichnet. Somit wird ein Teil der Fahrkorbmasse ausgeglichen und steht in Gleichgewicht zur Hubkraft. Das Druckmittel mit dem variablen Druck P1, das auf die weitere Arbeitsfläche A1 wirkt, erzeugt eine variable Hubkraft, die den restlichen Teil der zu hebenden Last, d.h. etwa 10 % der Masse des Fahrkorbes, des Hubkolbens und den im Fahrkorb befindlichen Personen entspricht. Dieser Teil der Last ist in Fig. 1 durch den Pfeil F1 angedeutet.The pressure medium with the pressure P2 of substantially constant Size creates a constant on the work surface A2 Lifting force that is approximately so large that, depending on the need, e.g. about 90% the mass of a car on the upper end of the piston 1 supported elevator corresponds. This part of the mass is in Fig. 1st indicated by arrow F2. Thus, part of the car mass balanced and is in balance with the lifting force. The pressure medium with the variable pressure P1, which is on the further work surface A1 acts, generates a variable lifting force that the rest of the too lifting load, i.e. about 10% of the mass of the car, the Reciprocating piston and the people in the car. This part of the load is indicated in Fig. 1 by arrow F1.

Wenn der Aufzug eine Halteposition erreicht hat, werden die ventile 33 und 43 in den Druckmittelleitungen 23 bzw. 24 in Sperrstellung gebracht, sodass der Fahrkorb stehen bleibt. Beim Abwärtsbewegen des Aufzuges werden diese Ventile geöffnet, und unter dem Einfluss der Gewichtskräfte F1 und einem Teil der Gewichtskraft F2 wird das Druckmittel aus den Druckräumen 7 und 13 über die Leitungen 23 und 24 in den Tank 39 zurückgeführt, wobei die beiden Förderpumpen 32 und 42 mitdrehen. Unterhalb einer bestimmten Gewichtskraft F1 werden die Förderpumpen 32 und 42 eingeschaltet um das Druckmittel aus den Druckräumen 7 und 13 über die Leitungen 23 und 24 in den Tank 39 zurückzufordern. Beim Aufwärtsbewegen des Hubkolbens 1 werden diese Ventile ebenfalls geöffnet.When the elevator has reached a stop position, the valves 33 and 43 in the pressure medium lines 23 and 24 in the locked position brought so that the car stops. When moving the These valves are opened, and under the influence of the elevator Weight forces F1 and part of the weight force F2 will Pressure medium from pressure rooms 7 and 13 via lines 23 and 24 returned to the tank 39, the two feed pumps 32 and 42 rotate. Below a certain weight F1, the Feed pumps 32 and 42 switched on to the pressure medium from the Pressure rooms 7 and 13 via lines 23 and 24 into tank 39 recovered. When the reciprocating piston 1 moves upwards, they become Valves also open.

Beim Ausführungsbeispiel gemäss Fig. 2 ist der aus dem Hubkolben 1, dem Arbeitszylinder 10 und der Führungsstange 15 bestehende Antrieb gleich aufgebaut wie in Fig. 1. Anstelle der Förderpumpe 32 ist in Fig. 2 ein vertikaler Zusatzzylinder 50 vorgesehen, in dem ein Zusatzkolben 55 dichtend geführt ist. Auf dem Zusatzkolben 55 ist ein Gegengewicht 57 angebracht; welches etwa 90 % der Masse des auf dem Hubkolben 1 abgestützten Fahrkorbes 62 entspricht. Die Masse ist mit M bezeichnet. Die Unterseite des vertikal angeordneten Zusatzkolbens 55 bildet eine dritte Arbeitsfläche 56, deren Grösse links neben den Zusatzkolben 55 in Fig. 2 separat dargestellt und mit A3 bezeichnet ist. Im Boden 53 des Zusatzzylinders 50 befindet sich eine Bohrung 57, die über eine Druckmittelleitung 23 mit der Bohrung 21 am Arbeitszylinder 10 in Verbindung steht und die Druckmittel aus dem Druckraum 54 unter der Arbeitsfläche 56 in den Druckraum 13 des Arbeitszylinders drückt, und zwar mit dem konstanten Druck P2.2 is that of the reciprocating piston 1, the working cylinder 10 and the guide rod 15 existing drive constructed the same as in Fig. 1. Instead of the feed pump 32 is in Fig. 2, a vertical additional cylinder 50 is provided, in which a Additional piston 55 is guided sealingly. On the additional piston 55 is a Counterweight 57 attached; which is about 90% of the mass of that on the Reciprocating piston 1 supported car 62 corresponds. The crowd is with M denotes. The underside of the vertically arranged auxiliary piston 55 forms a third work surface 56, the size of which is to the left of the Additional piston 55 shown separately in Fig. 2 and designated A3 is. There is a bore in the bottom 53 of the additional cylinder 50 57, via a pressure medium line 23 with the bore 21 on Working cylinder 10 is connected and the pressure medium from the Pressure chamber 54 under the work surface 56 in the pressure chamber 13 of the Working cylinder presses, with the constant pressure P2.

An der Bohrung 22 ist wiederum über die Druckmittelleitung 24 die Förderpumpe 42 angeschlossen, die Druckmittel mit variablem Druck liefert. Zwischen der Förderpumpe 42 und dem Ventil 43 zweigt eine Ueberströmleitung 45 ab, die zum Tank 39 führt und die mit dem Ueberdruckventil 47 und einem Nachsaugventil 46 ersehen ist. Saugseitig ist die Förderpumpe 42 über eine Leitung 64 mit der Druckmittelleitung 23 verbunden. Die Leitung 64 enthält ein Ventil 63, das in seinem Aufbau dem Ventil 43 entspricht. Zwischen der Förderpumpe 42 und dem Ventil 63 zweigt von der Leitung 64 eine Ueberströmleitung 65 ab, die ein den Ventilen 46 und 47 entsprechendes Ventile 66 und 67 enthält und zu dem Tank 39 führt.At the bore 22 is in turn via the pressure medium line 24 Feed pump 42 connected, the pressure medium with variable pressure supplies. One branches between the feed pump 42 and the valve 43 Ueberströmleitung 45, which leads to the tank 39 and with the Overpressure valve 47 and a suction valve 46 can be seen. On the suction side, the feed pump 42 is connected via a line 64 to the Pressure medium line 23 connected. Line 64 contains a valve 63, which corresponds to the structure of the valve 43. Between the Feed pump 42 and valve 63 branches off from line 64 Ueberströmleitung 65 from which the valves 46 and 47th corresponding valves 66 and 67 contains and leads to the tank 39.

Beim Heben einer Last wird mittels des Gegengewichtes 57 und des Zusatzkolbens 55 auf das unter der Arbeitsfläche 56 befindliche Druckmittel ein im wesentlichen konstanter Druck P2 ausgeübt, der sich über die Druckmittelleitung 23 und den Druckraum 13 auf die ringförmige Arbeitsfläche 5 am Hubkolben 1 fortpflanzt und diesen Kolben aufwärtsbewegt. Ausserdem wird über die Förderpumpe 42 Druckmittel mit dem variablen Druck P1 zur weiteren Arbeitsfläche A1 im Innern des Hubzylinders 1 gefördert, was den Hubkolben 1 ebenfalls aufwärtsbevegt. Beim Senken des Aufzuges wird das Druckmittel aus den beiden Druckräumen 7 und 13 des Antriebs über die Druckmittelleitung 23 bzw. 24 in den Druckraum 54 des Zusatzzylinders 50 zurückgedrängt, wobei sich der Zusatzkolben 53 mit dem darauf befindlichen Gegengewicht 57 nach oben bewegt.When lifting a load, the counterweight 57 and the Additional piston 55 on the one located under the working surface 56 Pressure medium exerted a substantially constant pressure P2, the the pressure medium line 23 and the pressure chamber 13 on the propagates annular work surface 5 on the reciprocating piston 1 and this Piston moved up. In addition, the feed pump 42 Pressure medium with the variable pressure P1 to the further work surface A1 promoted inside the lifting cylinder 1, which also the reciprocating piston 1 aufwärtsbevegt. When the elevator is lowered, the pressure medium is released from the two pressure chambers 7 and 13 of the drive via the pressure medium line 23 or 24 pushed back into the pressure chamber 54 of the additional cylinder 50, the additional piston 53 with the one located thereon Counterweight 57 moved up.

Bei dieser Ausführungsform kann am der Tank 39 für das Druckmittel wesentlich kleiner bemessen werden, da eine grosse Menge des Druckmittels vom Zusatszylinder 50 aufgenommen wird. Dabei lässt sich in Abhängigkeit des Grössenverhältnisses der dritten Arbeitsfläche A3 zur ringförmigen Arbeitsfläche A2 eine Reduktion der Antriebsleistung bis zu 50 % erreichen. Eine weitere Reduktion der Antriebsleistung wird dadurch erreicht, dass im Beispiel gemäss Fig. 2 die Saugseite der Förderpumpe 42 über die Leitung 64 mit der Druckmittelleitung 23 verbunden ist, sodass die Förderpumpe 42 mit Druckmittel von konstantem Druck P2 gespiesen wird und nur noch die Druckerhöhung von P2 bis P1 erzeugen muss.In this embodiment, the tank 39 for the pressure medium be dimensioned much smaller, since a large amount of the Pressure medium is received by the additional cylinder 50. there depending on the size ratio of the third work surface A3 to the annular work surface A2 Reduction of drive power can reach up to 50%. Another The drive power is reduced by the fact that in 2 the suction side of the feed pump 42 via the Line 64 is connected to the pressure medium line 23, so that the Feed pump 42 is fed with pressure medium of constant pressure P2 and only have to generate the pressure increase from P2 to P1.

Beim Ausführungsbeispiel gemäss Fig. 3 ist in vorteilhafter weise die konstanten Druck liefernde Druckquelle mit dem Arbeitszylinder integriert, sodass sich eine kompakte, platzsparende Bauform ergibt. Hierzu ist der Arbeitszylinder 10 in seinem oberen Abschnitt 10' im Aussendurchmesser reduziert und weist einen stufenförmigen Uebergang zum grosseren Aussendurchmesser im unteren Abschnitt 10'' auf. Der obere reduzierte Abschnitt 10' ist von einem Zusatzzylinder 70 dichtend umgeben, an dessen Aussenseite das Gegengewicht 57' angebracht ist. Das obere Ende 71 des Zusatzzylinders 70 ist gegen den oberen reduzierten Abschnitt 10' des Arbeitszylinders 10 hin verdickt und liegt über eine Gleitringdichtung 72 am oberen Abschnitt 10' des Arbeitszylinders 10 an. Auch am unteren Ende 73 des Zusatzzylinders 70 ist eine Gleitringdichtung 74 vorgesehen, die am unteren verdickten Abschnitt 10'' des Arbeitszylinders 10 anliegt. Im Bereich des stufenförmigen Uebergangs vom oberen zum unteren Abschnitt des Arbeitszylinders 10 sind mehrere Durchgangslöcher 76 vorgesehen, die den Druckraum 13 des Arbeitszylinders 10 mit einem Druckraum 75 verbinden, dessen obere Stirnfläche 77 Ringform aufweist und vom Innendurchmesser des Zusatzzylinders 70 und dem reduzierten Aussendurchmesser des Zylinderabschnitts 10' begrenzt ist. Die gleichen Durchmesser begrenzen auch eine ringförmige Arbeitsfläche A3, rechts im Fig. 3 dargestellt, die vom verdickten oberen Ende des Zusatzzylinders 70 gebildet wird.3 is advantageously the constant pressure supplying pressure source integrated with the working cylinder, so that results in a compact, space-saving design. For this is the Working cylinder 10 in its upper section 10 ' Reduced outside diameter and has a stepped transition to the larger outside diameter in the lower section 10 ''. The upper reduced section 10 'is from an auxiliary cylinder 70 surrounded in a sealing manner, on the outside of which the counterweight 57 ' is appropriate. The upper end 71 of the additional cylinder 70 is against the upper reduced section 10 'of the working cylinder 10 down thickened and lies on the upper section via a mechanical seal 72 10 'of the working cylinder 10. Also at the lower end 73 of the Additional cylinder 70, a mechanical seal 74 is provided, which on lower thickened portion 10 '' of the working cylinder 10 abuts. in the Area of the step transition from the upper to the lower Section of the working cylinder 10 are a plurality of through holes 76 provided that the pressure chamber 13 of the working cylinder 10 with a Connect pressure chamber 75, the upper end face 77 of which has an annular shape and the inner diameter of the auxiliary cylinder 70 and the reduced one Outside diameter of the cylinder section 10 'is limited. The same diameter also limit an annular work surface A3, shown on the right in Fig. 3, the thickened upper end of the Additional cylinder 70 is formed.

In diesem Beispiel ist die Förderpumpe 42 in der Bodenplatte 20' des Arbeitszylinders 10 eingebaut. Sie ist mit ihrer Saugseite an der Bohrung 23 und mit ihrer Druckseite an der Bohrung 21 angeschlossen. Auf der Saugseite und auf der Druckseite der Förderpumpe sind je ein Ventil 43 bzw. 63 vorgesehen, als Schalt- oder Proporitonalventil ausgebildet, angeordnet zum Oeffnen und Schliessen der betreffenden Leitung.In this example, the feed pump 42 is in the bottom plate 20 'of the Working cylinder 10 installed. It is on the suction side Bore 23 and connected with its pressure side to the bore 21. There are one on the suction side and one on the pressure side of the feed pump Valve 43 or 63 provided as a switching or proportional valve trained, arranged to open and close the concerned Management.

Beim Heben einer Last mittels des Antriebes gemäss Fig. 3 sind die Ventile 43 und 63 geöffnet und der Zusatzzylinder 70 gleitet unter dem Einfluss des Gegengewichtes 57' am Arbeitszylinder 10 abwärts. Dabei wird das im Druckraum 75 befindliche Druckmittel mit dem Druck P2 über die Löcher 76 in den Druckraum 13 des Arbeitszylinders 10 verdrängt. Das Druckmittel wirkt einerseits auf die Arbeitsfläche A2 am unteren Ende 3 des Hubkolbens 1 und hebt diesen an, andererseits gelangt Druckmittel über die Bohrung 21 zur Saugseite der Förderpumpe 42 und wird von dieser mit dem Druck P1 in den Druckraum 7 des Hubkolbens 1 gefördert. Dieser Teil des Druckmittels wirkt auf die Arbeitsfläche A1 und unterstützt die Aufwärtsbewegung des Hubkolbens 1.3 are when lifting a load by means of the drive Valves 43 and 63 opened and the additional cylinder 70 slides under the influence of the counterweight 57 'on the working cylinder 10 downwards. The pressure medium located in the pressure chamber 75 becomes the pressure P2 via the holes 76 in the pressure chamber 13 of the working cylinder 10 repressed. The pressure medium acts on the one hand on the work surface A2 at the lower end 3 of the lifting piston 1 and lifts it, on the other hand pressure medium passes through the bore 21 to the suction side of the feed pump 42 and is from this with the pressure P1 in the pressure chamber 7 of Reciprocating piston 1 promoted. This part of the pressure medium acts on the Work surface A1 and supports the upward movement of the reciprocating piston 1.

Bei einer Senkbewegung der Last, bei der die Ventile 43 und 63 ebenfalls offen sind, drückt der Hubkolben 1 das Druckmittel aus dem Druckraum 7 über den Kanal 17 der Führungsstange 15 und die Förderpumpe 42 zum Innenraum 13 des Arbeitszylinders 10. Aus diesem Raum wird dann das Druckmittel über die Löcher 76 in den Druckraum 75 gedrückt, wobei der Zusatzkolben 70 wieder in die obere in Fig. 3 gezeichnete Stellung aufwärtsbewegt wird. Bei ruhendem Antrieb sind die Ventile 43 und 63 in geschlossener Stellung. With a lowering movement of the load, with the valves 43 and 63 are also open, the piston 1 pushes the pressure medium from the Pressure chamber 7 via the channel 17 of the guide rod 15 and the Feed pump 42 to the interior 13 of the working cylinder 10. For this The pressure medium then becomes space via the holes 76 in the pressure space 75 pressed, the additional piston 70 again in the upper in Fig. 3rd drawn position is moved upwards. When the drive is stationary the valves 43 and 63 in the closed position.

Das Ausführungsbeispiel gemäss Fig. 4 ist gegenüber dem gemäss Fig. 3 dadurch abgewandelt, dass der Arbeitszylinder 110 in zwei axial zueinander verschiebbare Abschnitte 110' und 110'' unterteilt ist, wobei der obere Abschnitt 110' eine ähnliche Form aufweist wie der Zusatzzylinder 70 in Fig. 3. Der obere Zylinderabschnitt 110' ist an seinem oberen Ende 111 ebenfalls verdickt ausgebildet und mit einer Gleitringdichtung 112 versehen. Er gleitet mit diesem Ende am Hubkolben 1. Das untere Ende 111 des Zylinderabschnitts 110' ist dichtend am feststehenden unteren Abschnitt 110" des Arbeitszylinders 110 geführt, wozu die Gleitringdichtung 112 im verdickten Ende 111 des oberen Zylinderabschnitts 110' vorgesehen ist. Zwischen dem Innendurchmesser des oberen Zylinderabschnitts 110' und dem Aussendurchmesser des Hubkolbens 1 ist ein Druckraum 75' eingeschlossen der am oberen Ende von den Stirnwand 11' begrenzt wird, die die ringförmige Arbeitsfläche A3 bildet. An der Aussenseite des oberen Zylinderabschnitts 110' ist das Gegengewicht 57'' befestigt. Die Förderpumpe 42 ist gleich ausgebildet und in die Bodenplatte 20" eingebaut wie beim Beispiel gemäss Fig. 3. Dementsprechend ist auch die Wirkungsweise gleich wie die zu Fig. 3 beschriebene, d.h. beim Anheben der Last drückt der obere Zylinderabschnitt 110' unter dem Einfluss des Gegengewichtes 57" Druckmittel mit dem konstanten Druck P2 in den Druckraum 13 des Arbeitszylinders 110, wodurch der Hubkolben 1 angehoben wird. Gleichzeitig gelangt Druckmittel aus dem Druckraum 13 über die Bohrung 23 zur Förderpumpe 42, die es mit dem variablen Druck P1 in den weiteren Druckraum 7 des Hubkolbens 1 liefert. Dieses Druckmittel wirkt auf die weitere Arbeitsfläche A1 und unterstützt die Aufwärtsbewegung des Hubkolbens. Beim Absenken der Last wird das Druckmittel aus den Druckräumen 7 und 13 in den vom oberen Zylinderabschnitt 110' begrenzten Druckraum 75' gedrückt, wobei das Druckmittel aus dem Druckraum 7 über die Förderpumpe 42 zunächst in den Druckraum 13 verdrängt wird, bevor es zum Druckraum 75' gelangt.The embodiment according to FIG. 4 is compared to that according to FIG. 3 modified in that the working cylinder 110 in two axially sections 110 'and 110' 'which are displaceable relative to one another, the upper portion 110 'having a shape similar to that Additional cylinder 70 in FIG. 3. The upper cylinder section 110 'is on its upper end 111 is also thickened and with a Mechanical seal 112 provided. It slides on with this end Reciprocating piston 1. The lower end 111 of the cylinder section 110 'is sealing against the fixed lower section 110 "of the Working cylinder 110 guided, for which purpose the mechanical seal 112 in thickened end 111 of the upper cylinder portion 110 'is provided is. Between the inner diameter of the upper cylinder section 110 ' and the outer diameter of the reciprocating piston 1 is a pressure chamber 75 ' included that is delimited at the upper end by the end wall 11 ' that forms the annular work surface A3. On the outside of the upper cylinder section 110 'is the counterweight 57' ' attached. The feed pump 42 is of the same design and into the Base plate 20 "installed as in the example according to FIG. 3. Accordingly, the mode of operation is the same as that of FIG. 3 described, i.e. the upper one presses when lifting the load Cylinder section 110 'under the influence of the counterweight 57 " Pressure medium with the constant pressure P2 in the pressure chamber 13 of the Working cylinder 110, whereby the reciprocating piston 1 is raised. At the same time, pressure medium passes from the pressure chamber 13 via the Bore 23 to the feed pump 42, which it with the variable pressure P1 in supplies the further pressure chamber 7 of the reciprocating piston 1. This pressure medium affects the further work surface A1 and supports the Upward movement of the reciprocating piston. When lowering the load it will Pressure medium from the pressure rooms 7 and 13 in the from the upper Cylinder section 110 'limited pressure space 75' pressed, the Pressure medium from the pressure chamber 7 via the feed pump 42 initially in the pressure chamber 13 is displaced before it reaches the pressure chamber 75 '.

Abweichend von den beschriebenen Beispielen kann anstelle der Druckquelle, die Druckmittel mit im wesentlichen konstanten Druck liefert, ein Blasenspeicher oder ein Kolbenspeicher verwendet werden. Auch können die an den Druckräumen 7 und 13 angeschlossenen Druckquellen vertauscht werden, d.h. dass dem Druckraum Druckmittel mit konstantem Druck und dem Druckraum 13 Druckmittel mit variablem Druck zugeführt wird. Der beschriebene Antrieb ist nicht nur für Aufzüge vervendbar; er kann z.B. auch für auf- und abbewegbare Schlitten an Werkzeugmaschinen, Hebeplatform bei Kranen, Hubstapler, Hebebühnen, aktive Auto- bzw. Lastwagenstossdaempfer, etc. verwendet werden.Deviating from the examples described, instead of Pressure source, the pressure medium with a substantially constant pressure supplies, a bladder accumulator or a piston accumulator can be used. Also connected to the pressure rooms 7 and 13 Pressure sources are interchanged, i.e. that the pressure chamber pressure medium with constant pressure and the pressure chamber 13 pressure medium with variable Pressure is supplied. The drive described is not only for Lifts can be used; e.g. also for moving up and down Carriage on machine tools, lifting platform for cranes, forklifts, Lifting platforms, active car or truck shock absorbers, etc. are used become.

Bei Antrieben mit sehr grossem Hub können nach Bedarf, eines, zwei oder mehr als zwei Distanzstücke 25 sowie 25' und 27 vorgesehen sein, die dann mit entsprechendem gegenseitigem Abstand im Hubkolben 1 befestigt bzw. über Seile 26 aneinander angehängt sind. Weiter kann beim Beispiel gemäss Fig. 1 die Saugleitung der Förderpumpe 42 statt an den Tank 39 an die Leitung 34 angeschlossen sein wie dies in analoger Weise bei den anderen Beispielen der Fall ist. Das Gegengewicht 57 kann direkt oder mit Seilen ueber eine an den Zusatzkolben bzw. Zusatzzylinder befestigte Rolle aufgehaengt sein, womit die Masse des Gegengewichts halbiert wird. Der Elektromotor 41 kann an einem Frequenzumrichter und dieser an eine elektronische Regelkarte angeschlossen sein, die dann Steuersignale an den Frequenzumrichter und die Ventile liefert. Die Ventile sind als Schalt- oder Proportionalwegventile vorgesehen, die auch mit pulsmodulierten Signalen gesteuert werden koennen. Bei Antrieben kann nur ein Ventil in die Druckmittelleitung 23 oder 24 eingebaut werden. Die Filter koennen in die beide Druckmittelleitungen 23 und 24, oder nur in eine Druckmittelleitung 23 oder 24 eingebaut werden.For drives with a very large stroke, one or two can be used as required or more than two spacers 25 and 25 'and 27 may be provided, then with a corresponding mutual distance in the reciprocating piston 1 attached or attached to each other via ropes 26. Can continue 1, the suction line of the feed pump 42 instead be connected to the tank 39 on line 34 as shown in FIG is analogously the case with the other examples. The Counterweight 57 can be attached directly or with ropes to the Additional pistons or additional cylinders attached to the roller must be suspended, which halves the mass of the counterweight. The electric motor 41 can be connected to a frequency converter and this to an electronic Control card connected, which then control signals to the Frequency converter and the valves supplies. The valves are as Switching or proportional directional valves provided, which also with pulse-modulated signals can be controlled. Drives can only one valve can be installed in the pressure medium line 23 or 24. The filters can in the two pressure medium lines 23 and 24, or can only be installed in a pressure medium line 23 or 24.

Claims (5)

  1. Hydrostatic drive for lifting and lowering and for holding loads, particularly for lifts, including a working cylinder (10), which defines a first pressure space (13) connected to a pressurised medium source, a lifting piston (1) sealingly guided in the working cylinder (10) and a guide rod (15), which is disposed in the working cylinder (10) and projects into the interior of the lifting piston (1), which sealingly surrounds the guide rod (15), the end of the lifting piston (1) projecting into the first pressure space (13) affording an annular end surface (5) acted on by the pressurised medium, and in which the interior of the lifting piston (1) defines a second pressure space (7), to which an individual pressurised medium source (40) is connected, one of the pressurised medium sources supplying pressurised medium with a variable pressure, characterised in that secured in the lifting piston (1) there is at least one spacer ring (27) sliding on the guide rod (15) and that arranged in the working cylinder (10, 110) there is at least one spacer ring (25) sliding on the guide rod (15) and on the working cylinder (10, 110), which is connected to the lifting piston (1) by means of flexible tension elements (26).
  2. Drive as claimed in Claim 1 including a counterweight (57) for counterbalancing a proportion of the load to be lifted by the lifting piston (1), characterised in that the counterweight (57) is arranged on an additional cylinder (70), which sealingly surrounds the working cylinder (10, 110) to define a space (75) acted on by pressurised medium, that this space (75) communicates with the first pressure space (13) of the working cylinder (10) and that in order to define the space (75) acted on by the pressurised medium, the diameter of the outer surface of the working cylinder (10) is reduced in a stepped manner.
  3. Drive as claimed in Claim 1 including a counterweight (57) for counterbalancing a proportion of the load to be lifted by the lifting piston (1), characterised in that the working cylinder (110) is divided into a fixed cylinder section (110") and a movable cylinder section (110'), which is axially movable on it and is sealingly guided on the fixed cylinder section (110') and defines between it and the lifting piston (1) a space (75') acted on by pressurised medium and that the counterweight (57") is arranged on the axially movable cylinder section (110').
  4. Drive as claimed in Claim 2 or 3, characterised in that a pump (42) is provided as the pressurised medium source supplying a variable pressure, which is provided on the inlet side and the outlet side with valves (43, 63) and that the pump (42) is accommodated with the valves (43, 63) in the base (20', 20") of the working cylinder (10, 110).
  5. Drive as claimed in one of Claims 1 to 3, characterised in that provided in the interior of the lifting piston (1) starting from its end receiving the load there is a throttling rod (60), which extends into a passage (17) in the guide rod (15) on downward movement of the lifting piston (1).
EP98914771A 1997-04-30 1998-04-28 Hydrostatic displacement drive for lifting and lowering and holding loads, in particular for lifts Expired - Lifetime EP0979357B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
CH01004/97A CH689211A5 (en) 1997-04-30 1997-04-30 Hydrostatic drive for lifting and lowering and holding of loads, especially for Elevators.
CH100497 1997-04-30
PCT/CH1998/000173 WO1998049085A2 (en) 1997-04-30 1998-04-28 Hydrostatic displacement drive for lifting and lowering and holding loads, in particular for lifts

Publications (2)

Publication Number Publication Date
EP0979357A2 EP0979357A2 (en) 2000-02-16
EP0979357B1 true EP0979357B1 (en) 2003-02-26

Family

ID=4200218

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98914771A Expired - Lifetime EP0979357B1 (en) 1997-04-30 1998-04-28 Hydrostatic displacement drive for lifting and lowering and holding loads, in particular for lifts

Country Status (13)

Country Link
US (1) US6422349B1 (en)
EP (1) EP0979357B1 (en)
JP (1) JP2001527497A (en)
CN (1) CN1096577C (en)
AT (1) ATE233374T1 (en)
AU (1) AU6916998A (en)
BR (1) BR9809430A (en)
CH (1) CH689211A5 (en)
DE (1) DE59807321D1 (en)
ES (1) ES2189153T3 (en)
PT (1) PT979357E (en)
TR (1) TR199902647T2 (en)
WO (1) WO1998049085A2 (en)

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DE50002755D1 (en) * 1999-08-25 2003-08-07 Bucher Hydraulics Ag Neuheim HYDRAULIC ELEVATOR WITH A PRESSURE STORAGE THAT WORKS AS A COUNTERWEIGHT AND METHOD FOR CONTROLLING AND REGULATING SUCH A ELEVATOR
GB0329785D0 (en) * 2003-12-20 2004-01-28 Stannah Lifts Ltd Improvements in or relating to drive systems
US7614829B2 (en) * 2005-02-09 2009-11-10 Thomas Jr Samuel M Extendible building post
CA2507149A1 (en) * 2005-05-12 2006-11-12 P & M Design & Consulting Ltd. Pneumatic cylinder
US20060264275A1 (en) * 2005-05-18 2006-11-23 David Hammeke Retractable structure for mounting a device
GB0511908D0 (en) * 2005-06-11 2005-07-20 Stannah Lifts Ltd Improvements in or relating to drive systems
US8640829B2 (en) * 2008-07-16 2014-02-04 William P. Block, JR. Hydraulic elevator system
CN102275593B (en) * 2010-06-11 2015-03-04 北京铁道工程机电技术研究所有限公司 Pit type train lifting jack of high-speed multiple unit
CN102374207A (en) * 2010-08-17 2012-03-14 沈传良 Double-energy storage internal and external type plunger cylinder
US20150210518A1 (en) * 2014-01-27 2015-07-30 Chung-Yi Yang Anti-overpressure double-acting threaded jack

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US2269786A (en) * 1941-04-28 1942-01-13 Vickers Inc Power transmission
DE1031945B (en) * 1953-10-26 1958-06-12 Helmut Rudolph Hydraulically operated motor vehicle lifting platform
US3425322A (en) * 1965-09-17 1969-02-04 Fiat Spa Hydraulic slide control
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US3548573A (en) * 1968-04-17 1970-12-22 Cessna Aircraft Co Cylinder with integral accumulator
SE8002428L (en) * 1980-03-28 1981-09-29 Mecman Ab DIMENSION DEVICE FOR SINGLE-ACTIVE PRESSURE CYLINDER
HU184796B (en) * 1980-06-26 1984-10-29 Sandor Rajzo Hydrostatic drive
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US5860491A (en) * 1996-07-18 1999-01-19 Advantage Lift Systems, Inc. Hydraulic lift system and method for retrofitting

Also Published As

Publication number Publication date
DE59807321D1 (en) 2003-04-03
WO1998049085A3 (en) 1999-02-11
TR199902647T2 (en) 2000-03-21
AU6916998A (en) 1998-11-24
WO1998049085A2 (en) 1998-11-05
US6422349B1 (en) 2002-07-23
PT979357E (en) 2003-07-31
JP2001527497A (en) 2001-12-25
ATE233374T1 (en) 2003-03-15
EP0979357A2 (en) 2000-02-16
BR9809430A (en) 2000-11-14
CH689211A5 (en) 1998-12-15
ES2189153T3 (en) 2003-07-01
CN1255959A (en) 2000-06-07
CN1096577C (en) 2002-12-18

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