DE1812251A1 - Cell or rotary vane pump - Google Patents

Description

DR. KURT-RUDOLF EIKENBERG PATENT ADVOCATE

ABEX CORPORATION

240/402

Cell or rotary vane pump

The invention relates to a cell or rotary vane pump, whose slide, which is guided in a rotor, forms cells by resting against a running surface of a race, which form a Pumped medium - starting from a suction opening in the area a suction zone - promote in the direction of a pressure opening in the area of a pressure zone, with the slide by means of Pressurized actuating devices are pressed against the running surface.

Essentially, a suction running surface and a pressure running surface are to be distinguished in the running surface of a race.

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the. The suction running surface moves away in the area of the suction zone of the pump on the diameter of the rotor, thereby increasing the volume of the two successive slides cells formed and enter through the suction opening Medium enters the cell. The cell transports the medium through a guide zone to the pressure zone. The pressure zone Correspondingly, the running surface of the running ring has a pressure running surface here, i.e. the running surface approaches the circumference of the rotor. Are the in slots in the rotor guided slide pushed back into this, so the volume of the cell is reduced, so that the medium out this escapes through the pressure or delivery opening.

In order to achieve a high level of efficiency with pumps of this type, it is necessary that the slide valve exactly on the Running surface slide, i.e. a seal between the running surface and the vanes must be created during the rotating movement of the rotor be given. Normally the centrifugal force already causes the slide to be pressed outwards against the running surface, and with a sufficiently high speed of rotation, this effect is sometimes sufficient for sealing between the slide and tread. However, since the pumps are increasingly being used even at low rotational speeds or have to process a medium of high viscosity, and sometimes dirt particles or a tight fit of the slide

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an outward movement of the in its slot To prevent the slide, the centrifugal force is generally not large enough to provide a permanent and effective seal between the edge of the slide and the running surface.

For this reason, there are usually separate slide actuating devices that additionally operate the slide push outwards, related. As slide actuators For example, springs can be used, but due to the relatively small space available in the rotor, they have to possess small size in order to in any case an outward-facing one Align the pressure force on the slide. Furthermore, springs are subject to material fatigue and relaxation, so that especially in high-performance pump construction there is a tendency not to use springs as actuating devices for the slides to use.

For an outward movement of the slide the medium pressure in the pump itself can still be used · As hydraulic actuation devices can either such a two-surface application or a three-surface application can be used. In any case a liquid pressure is exerted on a surface of the individual slide, so that it is in the direction of the tread is pressed. In an actuator of the two-face loading type, this pressure is usually applied

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on the inner and outer surfaces of the slider. The pressure force on the inner surface of the slide (second impact surface) tries this outwards against a smaller and oppositely directed pressure force on the outer one Surface or edge of the slide (first impact surface). The resulting force then causes outward movement of the slide.

In a rotary valve pump of the three-surface loading type, the medium pressure acts on three surfaces provided on each slide, the resulting force pushing the slide in the direction of the running surface with a predetermined strength. The compressive forces on two of the surfaces provided on each slide are substantially equal and opposite to one another, so that they cancel one another. The first impingement surface is a surface at the outer end of the slide and is subjected to a pressure which acts inwardly on the slide. The second acted upon t deposition flat is located at the inner end of the slide surface and is exposed to a pressure and entgegen- outward. set to which pressure acts on the first impingement surface.

The third application area on each slide is also provided on the inner base of the slide and, as a result of the pressure applied to it, causes a subsequent

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outward compressive force to maintain the fluid seal between the outer end of the slider and the tread. An example of a three-surface impingement type pump with hydraulic actuators for the vanes is further described in commonly assigned U.S. Patent Application No. 2,832,293. A piston arranged in the rotor is connected to each slide, which can be moved in the radial direction and acts on the inner end of the slide. In this example, the circumference of the piston defines the third impingement surface. To operate the various pistons, pressurized medium is provided, which is applied through a chamber in the rotor, which in turn is fed through a channel in the stationary wall plate on the side of the rotor and from the high pressure zone of the pump.

The German patent application No. P 15 28 934.6 of the same applicant shows a three-surface-acted pump, in which the rotor has an internal pressure chamber, into which a high pressure zone of the Pump pressurized medium is fed when the pressure in the chamber is below the pressure in the high pressure zone sinks. This type of three-face loading may include, for example, a piston that has an axial bore and its outer end with the inner edge of the corresponding

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Forms a backflow preventer valve to control the addition of pressure medium from a pressure zone into the chamber, which connects the inner ends of the pistons with one another. ^ When the external pressure in the slide slot increases the pressure in the inner Chamber that keeps the piston valve closed, then the medium pressure in the slide slot pushes the piston away from the slide valve, whereby the valve is opened and a Flow takes place through the elongated channel in the piston into the chamber until a substantially equilibrium Pressure is given. This compressive force acts equally on all pistons and acts on the slides through the pistons, to press them against the running surface.

Slide pumps with hydraulic slide valve actuators, particularly those of the tri-face loading type, are generally well suited ^{for the seal between the slide and the tread during pumping cycle 1.} However, it has been found that if these pumps are used for a long time, so-called "chopjnarks" form on the running surface. Typically, the formation of these spots occurs in the downstream half of the suction surface.

Although the pump is still working satisfactorily, these rough spots indicate the beginning of an undesirable deformation process the pump running surfaces, the wear and tear

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of the slide and / or the race "accelerates and the The service life of the pump is absolutely shortened.

The actual sequence of movements of the pump slide during operation was checked through a special window in the wall plate with the aid of a stroboscopic ^. Light source explored. Tuck studies show that the "chopmarks" of the ups hit the slider to the Sauglaufflächen result if this jump or hop over the first rope Sauglaufflächen. In the area of the suction running surface, the running surface moves very far away from the surface of the rotor, as a result of which there is an increase in the volume of the cells that take up the medium. The observation shows that the vanes at their outer end are not accelerated sufficiently quickly to maintain contact with the suction running surface as it moves away from the rotor surface. In other words, the slide is pushed outward with insufficient force to be able to follow the outwardly evading suction running surface at higher rotational speeds.

Further studies showed that the phenomenon generally does not occur when the pump is working under load, but when the pump is idling, i.e. when the outlet pressure is in the range between 10 and 14 kp / cm or below. Such conditions occur during operation when the hydraulic downstream from the pump

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not toe the poor circulation or the well-maintained system ». '■ is burdened.

- The experiments have shown ₉ that T with these values ₁ - ':;

conditions.der. Auelaßdruok insufficient -high is _r * so i & i on.

■ ■ ". · ■

the hydraulic. The necessary force cannot be applied to actuating devices »to accelerate the slide fast enough in the radial direction outwards» so that the- "is? In contact with the running surface!" The pump also needs to be provided when the pump essentially does not need to supply any ana _{lassdruck (in} order to be able to apply a hydraulic force to the slide valve actuation device _9, which is necessary to prevent the slide from jumping over the suction surface.

One way sua? The solution to this problem is to provide a flow restriction through the outlet connection in order to throttle it, which has to create an air pressure * inside the pump. Performance .requires "(B ₀ Be. SiaeKtslioh four W) " ad d & i dadureh relative "eclmell @ia <s tbea? Hitzimg dee ÖXee- entry, if no additional SptiialWialeinfaeiten are provided Blnä«, such a solution is then © ^ - economically unacceptable · Alternatively, there was versmoliti, ela pressure drop between.

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ORIGINALINSPECTED

the inner and outer ends of each slide as a result of a to provide intermediate flow obstruction. This has the consequence that the slide in other phases of the Pump cycle undesirably high forces are applied. If the slide passes the guide zones, the pressure zones and the Sealing zones, the forces on the slides are then much greater than they are to maintain the seal is necessary in these zones. This leads to a significantly sharper wear on the outer slide edges.

The present problem is solved according to the invention in that the running surface of the race is arranged so that with a rotating pump immediately before opening a cell for pressure opening in the same a temporary one Pressure increase is given, and that means are provided which the in the cell immediately before opening to pressure opening Apply the prevailing pressure to the actuating devices at least of the slide or slides, which are in the direction of rotation in front of the suction opening.

The invention makes it possible in an advantageous manner to apply the necessary force to the slide with only a small proportion of the pump output volume. This proportion can be less than 10 % of the total volume. The drop in performance of the pump is therefore negligible. As a result of the invention, the jumping of the slide in the area of

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Suction opening can be significantly reduced or even prevented, without undesirable side effects occurring.

In a preferred embodiment of the invention it is provided that a small part of the medium from the Cell is discharged through a restriction flow when the cell approaches the pressure port, but before the Cell opens towards the pressure opening and thus an unobstructed one There is a flow to the pressure opening »If the medium has flowed through the limiting flow, this will small portion mixed again with the remaining discharge flow in the pump outlet.

The flow restriction is expediently designed in such a way that that a substantially constant back pressure on the medium in the cell is created when a rope of the medium through the Limiting flow is delivered and that this pressure is applied to the pressure actuation device, e.g. Pump is transmitted, which then has a sufficiently high force on other slides that are currently on the nursing surface are located, in order to prevent the slider from jumping.

Tests have shown that this actually results in constant contact between the slide and the running surface even with Outlet pressures are given, at which comparable pumps under the spring effect of the slide in the area, the suction

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area suffer. Experiments also made it clear that the conduction loss of a pump according to the invention is insignificant is that, however, the life of the pump is significantly increased.

Particularly useful embodiments of the invention are described in more detail below with reference to the drawings. Show

Fig. 1 is an axial section through a rotary slide

Over pump according to the invention, Fig. 2 is a section along the line 2-2 of the

I ¹ Ig. 1.

Fig. 3 is a cross section along the line 3-3

* \ ■ of Fig. 1, the pump in a

Position is shown in which the back pressure generation phase of pump cycle ^{1 is} just beginning,

Fig. 4 is a cross section of the pump similar to that in Fig. 3 but shows the pump in a position in which the back pressure generation phase just finished

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ORIGINAL INSPECTED

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Pig. 5. an enlarged part display a vane in the rotor when j this is in the routing zone ",

Pig. 6 ·. an enlarged! Eeildars division similar to Pig. 5, but when the slide is in the sealing zone;

Pig. 7 is a perspective view of a Slide according to the $ yps like him in Pig, and β is shown,

Pig. 8 is a plan view of a race or stator with an overlaid Polar network to the various opera- ■ "■ '■■ to show the tread zones of the running surface »the largest and smallest diameter and the pressure and suction running surface contains,.

Pig. 9 is a plan view of the rear of the Race according to Pig. 8 on a reduced scale,

Pig. 10 is a section along line 10-10 of FIG

Pig. 1 (front wall panel), ■■ "" * ■■ ». Pig. Figure 11 is a section along line 11-11 of Pig. 1 (rear wall plate),

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"-" ■■ "'- - ■ - ■.' ORIGINAL INSPECTED

^:! ■ ■ ■■■ "" ^f * ■ ^{"": i} ■ '' τ ^- ■■ ■■ ■■■ ■■. ·: * · ™ μ _"; ^ ·.

-13 -;

Pig. 12a -12e in graphical representation as a function of the Schiefcerposition in relation to the running surface;

a) the radial movement of the slide,

b) the volume of the basket pressure chamber,

c) the back pressure on the slide actuators,

d) the radial speed of the slide,

e) the centrifugal force and the required radial acceleration of the slide in a pump of the in 3? ig. 1

, to 11 lyps shown, Pig. Figure 13 graphically shows the rate of medium delivery from a cell during the back pressure generation phase of the pumping cycle,

14 is a schematic cross section of a rotary vane pump of the two-surface impingement type according to the invention.

ORJGiNALINSPECTED - 14 90983 3/0870

The invention described in more detail below is in can be used in a wide range for rotary vane pumps where the Rotary valve (also called wing) are pressed outwards against a running surface by means of a hydraulic force * Pumps of the two-surface exposure type as well as pumps are included in the scope of application Three-face loading type. First, the invention in connection with a pump of the three-surface-Beauf-

* Impact type described, the valve-controlled pistons for has the slide movement, and then a description will be given of a two-surface impingement type pump according to the present invention.

The pump according to FIG. 1 consists of a housing 1 with a substantially cylindrical inner chamber and an end cap 2 which, by means of a flange 3, engages telescopically into one end of the housing and there itself is sealed with an O-ring 4.-The housing and.

\ The end cap are connected together by bolts as shown in Fig. Apparent connected.

The front wall surface 5 of the cap 2 has an opening through which the pump shaft 6 is inserted. The wave 6 is mounted in ball bearings 7, which in turn are secured against axial displacement. A flexible seal 8 is located on shaft 6 and prevents oil leakage. The pumps-

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The shaft extends through the housing 1 starting from the Cap 2 through and is at its opposite end by means of a needle bearing 9 within a central bore in stored on the housing wall.

The end cap 2 carries a wall plate 10 and is sealed all around against this. The wall plate 10. has a smooth "flat, inner surface 11, which at a radial surface 13 of an annular race 14 rests The race 14 rests with its opposite radial surface 17, a flat, smooth surface 18 of a rear wall plate 19 and presses this wall plate against an inner shoulder in the housing 1. The race itself, or the housing and the raceway together are sometimes referred to as a kind of stator · The raceway is between the two Wall panels clamped by means of four bolts (not shown), the bolts through the bolt holes 20 (Fig. 3) in the raceway and through aligned holes 21 (Pig. 10) in both wall panels 10 and 19 are passed.

The inlet 22 leads radially into the housing 1 and is in communication with a pair of inner annular channels 23 »24» which surround the inner cavity within the housing. These annular channels 23 and 24 distribute that through the inlet 22 entered gaseous medium on suction ports in the wall panels.

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The race 14 is supported radially by a ■ - ;. annular rib 26 in the housing 1 between the annular Channels 23 and 24 is formed. The race ring surrounds a rotor 28 which is placed on the shaft'6 and over a spline 29 is taken ». The spline connection allows proper alignment of the rotor during dee Run between the opposing smooth surfaces and 18 of the front and rear wall panels. Both wall panels

™ have centrally arranged openings through which the shaft 6 is passed. The rotor has a number of radially arranged slide slots 31 (S ¹ Ig «3) in each of which a slide is arranged.

As shown in Fig. 3, the race 14 has a inward-facing running surface 34 »whose guide curve enables a balanced or symmetrical pump construction, in the paired, diametrically opposed low pressure, inlet or suction zones 36, guide zones 37 »high pressure-> Outlet \

) or pressure zones 38 and sealing zones 39 between the running surface 34 and the rotor 28 are present. To form the opposite zones, the tread 34 is shaped in sections so that a first pair of arcs is given, the extends over the guide zones 37. Although these arches are sometimes referred to as the largest diameter of the tread (see Flg. 8), they can easily be rotated

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drawn in, i.e. led inwards. A second pair Arches with a smaller diameter extends over the sifting zones 39 and is the smallest diameter tread defined. These pairs of bends are connected to one another by guiding levels for the suction and pressure zones » which extend over the low-pressure and high-pressure zones 36 "and 38. This type of formation of the guide curves the running surfaces is known in principle.

Together with the rotor and the slides, the running surface forms rotatable "cells". The outer edges of the slider keep constant contact with the running surface 34 of the race Hi and the side edges of the slide slide over the flat smooth surface 11 and 18 of the wall panels on the opposite Sides of the rotor. Thus, a pair of adjacent vanes divide the pumping gap between the rotor, the Tread and the wall panels in a number of cells for receiving, Transport or delivery of a gaseous medium, which is thus carried from the inlet to the outlet * One of these cells 40 shows Pig. 3.

The inlet 22 extends through the annular channels 23 and 24 around the race 14 and over into the wall panels 10 and 19 incorporated passages with the pairs of suction openings in connection, which have a distance of 180 ° and in the Surfaces 11 and 18 of the wall panels are arranged.

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Fig. 10 shows two suction openings 43 and 44; which are molded into the wall plate 10 and via the channel 24 loading. . ^! ■ will be sent »Pig. 11 shows two additional suction openings 16 and 46, which are enclosed in the wall plate 19 and are fed through the channel 23. These four suction openings are identical in size in the inner surfaces 11 and 18 of the wall panels and are in communication with the suction zones 36 between the rotor and the running surface Communicate ends 48 of the slide slots 31 when the rotor is rotating.

As FIG. 10 shows, the wall plate 10 has two diametrically opposite pressure openings 51 and 52. These Openings are preferably Φ-shaped in the flat surface the wall plate 11 arranged to a reversiMlitat of the race to enable and thus to allow a change in the direction of rotation of the pump. The pressure openings are arranged almost 90 ° away from the suction openings 43 and 44 and open into the pressure zones 38 between the eotor and the running surface. Fig. 3 shows that the leading edge of each print opening located downstream at the beginning of the raceway pressure surface.

The pressure openings 51 and 52 are via internal passages 54 and 55 in the wall panel 10 and the end cap

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- Connected to an outlet or dispensing nozzle 56. During operation, there is an external hydraulic circuit on the delivery port 56 (not shown) connected.

Each I-shaped pressure port 51 and 52 is through connecting semicircular grooves 59 and 60 to the end of the

Pressure area, which is adjacent to the sealing zone, is extended. The hats are in the raceway surfaces 13 and 17 (see Fig. 2, 3, 8 and 9) molded in. Each groove 59 and 60 opens the pumping gap around the cell towards the one immediately downstream located pressure opening in the pressure zone 38 of the corresponding wall panel.

The running ring is connected to the two wall panels a cylinder atift 61 in each surface 13 and 17 of the Running ring aligned. This cylinder pin is in one of the two holes 62 and 63 in each of the wall panel surfaces 11 and 18 of the race. The holes 62 and 63 are 90 ° apart, so that the direction of rotation of the Shaft 6 can be reversed when the pump is converted, by rotating the race ring by 180 ° around an axis transverse to its own axis and the cylinder pin on another Hole 63 or 62 in the wall plate is aligned.

The raceway grooves 59 and 60 are already for one

Reversibility of the pump and extend the wall

! plate pressure openings 51 and 52 to the end of the printing area,

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i.e. up to the adjacent sealing zone, independently, the direction of rotation of the shaft.

As Eige 4 shows, it is in the direction of movement of the rotor the suction surface portion of the running surface 34 is progressively withdrawn from the periphery of the rotor 28 via each suction zone 36, so that the volume of a cell 40 between the slides increases in this area.

Along the guide zone 37, the larger diameter of the running surface 34 slightly approaches the rotor. Along the pressure zone 38 the pressure surface approaches the rotor 28 and more closely. goes in the area of the sealing zones 39 close to the circumference of the Rotor. The radial movement of a slide that takes place is graphically in Pig. 12 shown. The gaseous one Medium is drawn into a cell 40 through the suction opening when the cell enlarges along the suction zone 36 * Most of the contents of the cell are released again when their volume increases as a result of movement through the pressure zone 38 reduced in size, so that a pumping process is associated with it is.

Each slide 32 is in its outer edge and the two opposite side edges with deep grooves 67 provided. The grooves 67 ensure that the force on the slide as a result of the action of the outer End surface of the slider with the print medium at all times

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OBJGSNAL INSPECTED

stands in broad equilibrium with the force that results the pressure in the slot guide 48 is applied to the inner end surface 79 of the slide.

For a high efficiency of the pumping operation it is necessary that between the valve tip and the running surface 34 a constant sealing contact is maintained, regardless of a change in the curvature of the tread. Use a type of gate valve with a double sealing lip, similar to the one in Pig. 3 example shown, then only the front or leading sealing lip of the slide touches the pressure surface, while only the rear or the following sealing lip touches the suction surface.

To the hydraulic actuation pressure on the slide to apply, one or more radial bores or cylinder pistons 69 are provided in the rotor 28, which are extend inwardly from the inner end of each slide slot 31, which is rounded in the form of a slot bore 48. The bores 69 are with their inner end through an annular Piston pressure chamber 71 connected. Apart from minor leakage losses, the medium can only pass through the radial bores 69 of the piston pressure chamber 71 can be supplied or removed.

The pressure chamber 71 is formed by an annular Groove 72 in the rotor 28 and a smaller groove 73 in one Bearing bush 74. The bearing bush is in a central opening

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fixed in the rotor 28 and sealed, e.g., by welding or brazing, and delimits the pressure chamber 71.

A substantially cylindrical piston shut-off member 76 is located in each radial bore 69. Each piston 76 has an axial bore 77 (see Pig. 5) and is slidably disposed in the bore 69, but with its outer sliding surface adapted to that of the bore that only negligible, small leakage losses can occur between these sliding surfaces. The outer end of each piston 76 has a tapered edge 78 which, together with the flat, inner end surface 79 of each slide 32, forms a shut-off device. The inner end surface of each piston preferably has a rounded portion 80, which represents a third, further application surface for the medium pressure within the pressure chamber 71, the force resulting therefrom pressing the piston against the inner end surface 79 of the relevant slide. The inlet of the pressure medium into the chamber 71 is regulated by the balance of forces on the piston, on the one hand by the pressure force directed inwardly away from the slide on the conical beveled edge 78 of the piston and on the other hand by an opposite, on the slide to directed pressure force is given, which is composed of the medium pressure in the chamber 71 and the centrifugal force. The length of the piston 76

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■ is so "dimensioned that one reciprocating in the radial direction Movement along with the pusher end surface 79

is possible, regardless of the radial position of the slide in the slide slot.

During operation, the piston works together with the slide and forms a valve 78, 79 »that is in the In the manner of a non-return valve acts / i.e. the introduction of the pressure medium into the chamber 71 and the backflow from the chamber prevented. When the medium pressure is in a slotted bore on the conical, beveled edge 78 of the piston 76 acts, the pressure in the chamber 71 exceeds sufficiently, then the piston moves in its bore 69 inward and the valve 78, 79 opens. The pressure medium in the sliding bore 48 then flows inward through the bores 77 and 69 in the pressure chamber 71 »whereby the medium pressure in this chamber rises again until the medium pressure which has caused the opening of the valve 78, 79 is equalized is. This movement takes place when the slide slot 31 is located in a zone in which the pressure is sufficiently high compared to the pressure in the chamber 71 to achieve the Valve open. Such hollow piston valves for the slide movement are in the pending German patent application No. P 15 28 934.6 described in more detail.

Each slide 32 is equipped with a channel or an outlet

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groove 82 on its downstream, i.e. trailing side

Mistake. In Pig. 7 this® groove is shown by., the inner or lower 'edge' 79 of the slide to just below, but not to the trailing upper Dicbtungalippe 83 of the slide is guided. In the cross-sectional drawing it can be seen that the outer surface 64 of the rotor has a central Edge projection 84 has. Prop. 5 and 6 show that the Groove 82 forms a valve with the edge projection 84. This

^ Valve is open, -when the slide protrudes from the rotor, e.g. if this point of the rotor is in a guide zone 37 and is closed if the slide is only -. protrudes slightly from the rotor, e.g. when this slide passes a sealing zone 39 «

Such media-carrying grooves are detailed in the copending application of Adams & Griffith, U.S. Patent Number 490 220, described in more detail. The recesses 82 are not claimed in this application, but their use is such grooves for pumps according to the invention

* appropriate as they generally allow better operating conditions.

The invention relates to the generation of back pressure or the provision of a pressure which is greater than the outlet pressure on the slide actuators to, in moments, in which the normal outlet pressure is too low, a sufficient one

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"■■". ■ !!!; ■ W ■: "■.: ■:" '. · ■

To muster force a jumping or skipping the Prevents slide over the suction surface. In the embodiment described in more detail, this is the same Just a moment, a little hurry of what is in every cell The medium is displaced by means of flow restriction devices and the back pressure created in this way in the basket pressure chamber 71 applied, which acts on all hydraulic actuators of the piston 7.6. The pressure in the chamber 71 acts thus on the piston of the slide, which is on the drip surface slide along, thus preventing these slides from jumping.

The flow limiting devices are appropriate molded into the front wall panel, like Pig. 10 shows. In the wall plate 10 is immediately before the start of the pressure zone (see Pig. 3) a small non-adjustable opening or a restriction flow 88 drilled in. This opening 88 is in communication with the throughflow 54, which in turn leads to the outlet or Discharge nozzle 56 is further guided (see Pig. 1 and 2). the Opening 88 is drilled open on the surface 11 of the wall panel 10 to form an opening 89 with a larger diameter. From the drilled one Opening 89 extends a T-shaped notched outflow slot 90 so that the opening at the moment with the groove 67 of a slide communicates by the

subsequent slide just the intermediate cell

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sealed against the suction opening (see »Pig. 3). The reamed one The opening 89 and the outlet socket 90 are more in.radial Direction arranged so that both open into the pump gap between the rotor outer surface 64 and the running surface 34.

A second, larger flow opening 91? also extends in the form of a tapering V-incision extending from the leading edge of each printing opening 51 and 52 to a point from which communication with the slide edge groove 67 is given at the moment in which the front sealing lip touches the pressure running surface. (see lig. 3). Ideally, the outer surface has the drilled out opening 89 from the top of the notched flow opening 91 in the circumferential direction a distance equal to the distance to the front ». whose sealing lip of a slide is the same.

Both the restricting flow 88 and the flow opening 91 are only on the upstream one Side of each pressure opening 51, 52 is necessary. - But should the ) The pump is designed to be reversible, so they are identical and corresponding Limiting flow rates 88, drilled openings 899 V-shaped outflow slots 90 and notched flow openings 91 symmetrically on the other side of each pressure port 51 »52 (see Fig. 10) to allow the same mode of operation when the raceway with opposite Rotation of the shaft is arranged reversely oriented * Eür

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den Pall that the pump only work with one direction of rotation should, it is therefore not necessary to have such flow limitation devices to be provided on the downstream side of the pressure port. The pressure opening in the wall plate itself can then have a length that corresponds to the length provided for in the construction, together with the wall panel

opening and the raceway recess illustrated effective Length is the same.

Since the medium is only passed through the front wall panel 10, but not through the rear wall panel, to the Outlet port 56 is dispensed is in the rear wall panel no pressure opening necessary, but a worthwhile one To achieve pressure equalization, it is appropriate that In the surface 18 of the rear wall panel 19 blind Ending outflow slots 93 are provided, the arrangement of which essentially corresponds to that of the front wall panel * The V-shaped slots 93 in the rear wall panel are conveniently rotated by a shallow blind hole 94 limited. These slots 93 are not part of the back pressure generation according to the invention and can accordingly omitted. Their providence, however, is a simple means of gradually balancing the pressure to achieve along the sealing lips of a slide in this position.

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The limiting flows provided with an unchangeable cross-section 88 and 'form the flow openings 91 provided with a variable cross section together flow channels through which the medium is already out each cell can flow out when it approaches the pressure outlet openings 51 and $ 2 arranged in the wall plate, However, without the direct connection with the pressure outlet openings is already established. In this context is

note that the leading edge of each pressure port is downstream on the imaginary line between the axis and the The beginning of the pressure tread is located (31g. 3). The advanced one Part of the tip of the "T" does not open into the pressure zone and is only provided to allow better communication with the raceway grooves 59 and 60 when the Rotation direction reversed »

The delivery of the medium from each cell through these restriction flows only takes a moment, however becomes at the same time during the subsequent forward movement of the cell causes a change in pressure along the flow paths. When the outlet pressure is low as a result of the flow through the flow-throughs a change in pressure is given, so that the medium in the cell during this moment is under higher pressure than it is the pressure at the outlet port located at the downstream end of each flow.

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909833/087 0 ORiGINAL, NSPHCTED

¹¹ "ιT ¹¹ W ¹ I ¹ I"' ¹ H ι «' .ti ^ i.mitn ι ι_ ι ΐΜΡΨτηνφι ·. . ,,, ",,,

This back pressure generation of the medium in a cell "begins when the cell, for example 40, is approximately in the position shown in Pig. 3, ie when the front edge of the leading slide of the cell has just sealed the suction opening and the fixed flow-through 88 has come into contact with the cell, just over the outflow slot 90 and through the side groove 67 of the leading slide This gradient reduces the volume of the cell, preferably at an approximately constant rate, as the cell approaches the printing surface (Beaohte Pig. 12a). As a result of this reduction in cell volume, medium is released from the cell, initially through the limiting flow 88, then through the flow opening 91. The resulting, ie increasing pressure is applied through the side groove 67 and di e groove 82 in the slide the inner end 48 of the slide slot and thereby causes the opening of the valve 78, 79 and a refilling of the supply of medium in the chamber 71, if this is necessary.

The rate of release of medium from the cell should preferably be for the period of time in which both slides (the Cell 40 limit) in contact with the size diameter of the

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Standing tread, im. be kept essentially constant, as Pig. 13 shows. This medium is released into the limiting flow 88, which remains constant in cross section, so that the flow causes an essentially constant pressure drop along the flow 88. This is also the

Back pressure in the cell 40 approximately constant. If the upstream slide the pressure running surface, so is it is increasingly pressed inwards (see Mg. 12d) and the rate of release of the medium from the cell increases accordingly. To prevent the increasing rate of delivery generates an unnecessarily high back pressure, it is expedient to provide a second, changeable flow 91, so that at the moment of increasing the delivery rate an increasing flow area is provided as a result of the tapered flow 91, so that a substantially constant back pressure can be maintained.

While this back pressure is being created in a cell, aidere slide. Slide over the suction surface (see Pig. 3X The pressure in the chamber 71 acts on all slide actuators, including those that control the slide on the drip runway are assigned, and thus prevents a jump leader Slider.

The height of the turning back can by suitable selection of the flow area of the limiting flow

909 83 3/087 0

Readings 88 and 91 can be changed.

If the pump is working under load, the pressure ayatem itself generates enough force in the sonieberbetaMgungB devices to ensure a constant contact of the slide on the running surface. However, if the pressure in the pressure system is low or almost zero, for example when the pump is in. Idling is and does not generate any pressure against a workload, then the delivery pressure, even if one takes into account the effect of the centrifugal force (see Fig. 12e), is not sufficient to extend the slide sufficiently far in the radial direction, as is necessary for a secure fit the slide valve on the suction valve is necessary · The pressure setting should ideally be slightly greater than the minimum pressure that is necessary to ensure that the slide valve is securely seated when the pump is idling. In general, under normal operating conditions, a pressure of between 7 and H kp / cm is sufficient, so that the size of the flow rates can be designed according to these values.

The generation of back pressure in the cell 40 is limited in duration, namely in the described preferred embodiment of the invention up to the point in time when there is a direct connection between the cell and the pressure port given is. It can be seen that the pressure generation phase is thus only over a short period of time

ORIGINAL INSPECTED - 32 -

909833/0870

Pump cycle ¹ extends to each cell. *

The portion of the medium that flows through the restrictions · flows 88 and 91 and is used to generate the Rtiokflusse is mixed in an advantageous manner with the main flow of the medium in the flow 54, which is fed to the outlet ( port 56. The percentage The proportion of the total medium conveyed that is passed through the limiting flow rate is small and is roughly in the order of magnitude of 10 % or less.

It has already been mentioned that the recess 82 in: In connection with the generation of back pressure a special «desired Task. If a slide is located in a ■ routing zone, these recesses enable communication between the space behind the slider and the inside Slotted hole 48 of the slider slot. Like in Pig. 5 shown is the pressure that is in the cell between two slides. developed when the spool volume decreases, due to this Pull grooves 82 to the lower end of the slider litz- · where it acts on the valve 78, 79.

It should be noted that in a pump as shown in the drawings, the volume capacity of the Piston pressure chamber 71 fluctuates during operation because in the different Rötorpoeitionen a different number of sliders on the pressure or * suction surfaces.

-, - ■. ' "ORIGINAL

909 833/0870

: finds. This change in volume capacity is indicated by a wavy line in Pig. 12b shown. The volume of the Piston pressure chamber 71 decreases when the slide begins to touch a suction running surface (see Pig. 12b). As the medium through the closed valve 78, 79 is basically locked, it can be expected that this decrease in the capacity of the Chamber 71 caused an increase in the medium pressure in it. However, it has been found that under the condition of one low outlet or delivery pressure, the chamber 71 is not always completely filled with medium, even if the volume capacity decreases. E.g. the presence of some foam or air bubbles can cause the decrease in volume does not pressurize the chamber 71. The back pressure generation has the consequence that the Chamber 71 is filled with medium and there is a minimum pressure in the chamber which is above the outlet pressure, so that sufficient force is applied to the actuating surfaces associated with the slides, and maintain contact between the running surface and the slides, including the slides on the suction running surface will.

Furthermore, when the volume capacity decreases, there is an additional pressure as a result of the pulsating pressure fluctuations in the chamber 71, an increase in the compressive force

- 34 -909833/0870

caused. From Pig. 12a and 12o it can be seen that the Chamber pressure increases before a slide hits the suction surface. This increase causes a force on the Slide actuating device which is sufficient to compensate for the shortfall shown hatched in FIG. 12e.

The pressure chamber 71 ″ should expediently be so large be that the increase in pressure in it results in sufficient contact between the slide and the running surface, but not so large that excessive pressure between the slide and the running surface could destroy the pump. With others The chamber 71 serves both as a buffer and as an internal connection between the various words inner operating surfaces of the slide. The pressure chamber 71 described here differs from the known piston chambers in that the latter were designed too small to limit the pressure increase and therefore slider tilting as a result and race wear occurred. The pressure chamber 71 according to the invention can be compared to the yolumen capacity the known piston chambers have more than four times the size.

The pressure chamber also serves, in its function as an intermediate storage device, to maintain a minimum pressure above normal Maintain outlet pressure. In practice, the chamber 71 is preferably designed so that one-pressure is maintained.

909833/08 7 0

- which is 70 to 105 kp / cm higher than the minimum exhaust pressure. The known designs of the chambers were dimensioned too small to effectively accommodate a similar usable volume To be able to hold the pressure.

Pig. Figure 13 shows the change in the delivery rate of a cell as it moves from the guide zone to the pressure zone during the pressure generation phase of the circulation cycle. The delivery rate is essentially constant up to the beginning of the pressure zone. The delivery of the medium through the flow 91, which can be changed in area, begins when the leading slide of the cell hits the pressure running surface. The increase in the flow rate which then occurs is in Pig. 13 represented by the rising course of the curve. The unimpeded flow of the medium to the pressure opening does not begin at the moment when the leading slide hits the pressure running surface, but preferably when a rope of the medium in the cell has been released through the flow opening 91. This increases the time for generating the back pressure, so that it is ensured that the pressure in the chamber 71 is maintained long enough at a sufficient level and that the pressure on the actuating piston. Slider including the? Sliders that are still on the suction surface, the applied force prevents the slider from tilting.

The preferred embodiment of the previously described

- 36 909833/0870

Invention "related to a pump of the three-surface Beaufsöhiagungs- ·" ⁴ type on the other hand illustrated in Pig 14 relates to a pump de sV ^v double-top Beaufschlagungstyps which has been designed according to the invention,....;

Ir. The pump according to Pig. 14 owns some equally

designed elements, such as the previously described pump des Three-face-type of occupancy. These designed the same Elements are therefore provided with the same reference symbols. In

W Fig. 14 resembles the shape of the race 14, the pressure openings 51, 52 and the suction openings 43> 44 to the elements described in connection with FIG. Likewise, in order to enable the direction of rotation of the shaft β to be reversed, the raceway is provided with grooves 59, 60 which cooperate with the pressure openings 51 »52 of the wall plate in the same way as previously described. ·

The housing structure according to Fig. 14 differs in that that leeine hydraulic pistons for actuating the slide 101 are provided in their slots, and that the inner ends 102 of the slide slots are connected to one another by annular notches or pressure spaces 104, which are shown in FIG the opposite surface sides of the rotor are incorporated. There are also no lower slide suction openings, corresponding to those denoted by the reference number 47 in the ' Pump of the three-surface loading type are provided "

- 37 -

909833/0870

• ORlGiNALiNSPECTEO

181225t

This separates the pressure space 104 and the inner ends of the slide slots from the suction openings.

The slides 101 have a sealing lip, i.e. they do not have two ■ grooves on the edges of the slides Sealing lips as described above. Likewise, these slides are not corresponding with a passage the groove 82 is provided. In this two-face impingement type pump the pressure acts on the outer end surface (1st bearing surface) of the slide inside and the media pressure in the inner end 102 of the slider slot on the inner surface 105 (2nd impingement surface) of the slide to the outside.

The openings 89 in the guide zones 37 between the suction and pressure ports are via flow restrictors with the pressure. outlet or discharge port 56 of the pump connected as this schematically in Pig. 14 is shown with the reference numeral 88. Each opening 89 has a beveled slot outlet 90, similar to that described varher. The apex of the slot 90 preferably extends up to just over the leading edge of a cell's upstream vane if that cell's leading vane • has just sealed the suction opening. Through this optimal Condition is a channel for the medium outflow provided when the volume of the closed cell through. Transition of

- 38 909833/0870

Reduced running surface in the guide zone.

The pressure in the direction of flow above the opening 88 is passed on into the pressure chambers 104 by means of flow devices 107 (shown schematically). This pressure acts on all slides and pushes them outwards.

If the pump is reversible - as shown - then there are similar flow restrictions on the opposite one Side, i.e., on the downstream side of each pressure port 51, 52 is provided. In each passage 107 devices 108, for example one-way valves, which block in one direction, are provided so that the medium can flow into the pressure spaces 104 can be entered, ™ but cannot leave it again, which means that the openings 89 are always below the higher back pressure. Thus, the other opening 89 on the opposite side of the pressure opening is only used when the direction of rotation of the pump reverses, and can of course - as before - be omitted if it is only is a pump with one direction of rotation.

A limiting flow that can be changed in terms of area 91 extends from the leading edge of the pressure port. Preferably the apex is the beveled V-shaped groove 91 arranged so that pressure medium is discharged from the cell through this flow directly to the outlet port when the leading slide of a cell straight on the print run

-39 909833/0870

"surface runs up and is thereby pressed inwards. This means that the apex of the groove 91 extends straight to over the rear of the leading slide when

this is located at the beginning of the printing surface.

During the operation of the two-surface application type pump according to ^ ig. 14 causes the running surface 34, which is guided slightly inward, in the region of the guide zone to reduce the cell volume when it moves along the guide zone. It is advantageous to keep the feed angle constant so that the rate of release of medium through the flow 88 is also kept constant with a constant area, and accordingly a constant back pressure is maintained in the cell. This pressure acts on the pressure chamber 104 via the throughflow 107 and the valve 108. The pressure in the pressure chamber 104 acts on the inner ends 105 of all slides and pushes them outward. The throughflow opening 88 should preferably be designed so that the back pressure has a sufficient height to prevent the slide from tilting during its movement over the suction running surface. The cross-sectional area of the V-slot 91 is similarly advantageous to design in order to obtain an essentially constant back pressure in the cell and thus in the pressure chamber 104 when the leading slide is pressed inward as a result of running onto the pressure running surface.

■ - 40 909833/0870

The exact location "of the passages 88 and 91" is carried out under the aspect of optimal control, but it is obvious that also deviating arrangements at least bring some of the advantages of the invention »For example, it is evident that by arranging a single of the two throughflows 88 or 91 also generate a back pressure can be achieved though the results. - .. then are not optimized. It is essential that an inner Back pressure is generated, which is high enough to for a sufficient time a compressive force on the slide actuators exercise so that a constant contact between the sliders and the running surface is maintained will. , '' ■ "... 'Γ'" '

Patent claims »

Iiv / bf

: ■ -. - 41 909833/0870

Claims (1)

Patent claims: 1. Cell or rotary vane pumps, whose vanes, guided in a rotor, form cells by contacting a running surface of a running ring , the slide being pressed against the running surface by means of actuating devices acted on by means of conveying medium pressure, characterized in that the running surface of the running ring (14) is arranged in such a way that, when the pump rotates, immediately before opening a cell for pressure opening (51 »52) in the same there is a temporary increase in pressure, and that devices are provided which apply the pressure prevailing in the cell immediately before opening to the pressure opening to the actuating devices (76) of at least the slide or slides (32) which are in the direction of rotation in front of the suction opening (43 »44) are located. - 42 909833/0870 2. Apparatus according to claim 1, characterized in that the pressure opening (51 »52) is arranged offset in the direction of rotation from the pressure zone (38) and that a limiting flow (88, 89) before opening a cell to the pressure opening (51, 52) connects the pressure opening with the cell " 3. Apparatus according to claim 2, characterized in that the limiting flow (88) has an opening (89) with a shape to keep the level of the temporary pressure increase constant during its duration ". 4. Device according to one of the preceding claims, characterized in that _t the or limitation flows (88) are formed in both sides of the rotor (28) that are available wall panels (10, 14). 5. Device according to one of the preceding claims, characterized in that a groove (91) is arranged in the wall plate (10) on the side opposite to the direction of rotation of the pressure opening (51> 52). 6. Device according to one of the preceding claims, characterized in that the inwardly facing loading . - 43 909833/08 70 surfaces (79) of the slide actuator (76) in a common, annular pressure chamber (71) are arranged, the pressure chamber with at least one at a higher cell pressure than the chamber pressure Check valve (78, “79) is provided for filling the chamber (71) with pressure medium. 7t device according to one of claims 1 to 5, characterized in that a connecting continuous flow (107 »108) between the zone of the pump in which the temporary increase in pressure is given and the impinging surfaces (79) of the slide in the area of the suction opening (43, 44) is provided « 8. Device according to one of the preceding claims, characterized in that the limiting flow rates (88, 69) and / or grooves (90, 91) are arranged symmetrically on both sides of the pressure openings (51, 52). 909833/0870 Blank page