DE2225327A1 - Vacuum pump - Google Patents

Description

In the mechanical pumps used up to now to generate a primary vacuum, such as in the case of vane pumps or oscillating piston pumps there are friction areas in the active pumping parts that have to be lubricated. By between the active pumping parts as a result of the existing oil film, these conventional mechanical pumps achieve a high pressure performance because of the Oil film virtually eliminates any play between the active parts and thereby greatly reduces lateral and radial leakage losses of the pump medium. In addition, this oil is the The heat generated by the pumping work and the mechanical friction is very well distributed in the mass of the pump, whereby

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

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different dixatations can be avoided which would lead to a pressing of the various organs.

Unfortunately, these pumps are not perfectly sealed to the outside and the lubrication of the friction areas causes a Contamination of the pump medium and the pump rooms. Despite many attempts to improve this, result in many applications of such pumps have serious disadvantages.

In order to prevent these disadvantages once and for all, volumetric vacuum pumps have already been proposed in which the active parts roll precisely and inevitably in a circular translatory manner on one another, without friction occurring and lubrication being required, so that the interior of the pumping area both to the outside how it is completely sealed against the lubricated pump organs. Such pumps are described above all in the French additional patent specification 93 0 ^ 8 of September 29, 1967 by the applicant.

In order to come close to the performance of conventional mechanical pumps for generating a primary vacuum, the pumps in this The vacuum pumps described in the additional patent specification meet the following conditions:

1. A perfect, very effective training of the active pumping organs;

2. A very small and always constant side and radial play between the effective pumping surfaces, what requires:

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

high accuracy in the kinematic function without any deflection or deformation due to the forces arising from the movement and the pressure effects;

Elimination of any different dilation due to the pumping work and the mechanical Movement generated warming, which inevitably changes the play between the effective pumping surfaces would result.

Such a pump consists essentially of a stationary one Housing with a stationary disc with a spiral band on at least one side, one of these stationary disk opposite, supported in the housing movable disk also with at least one helical band of equal angular amplitude in engagement with the band of the fixed disc, with one of at least three synchronously running crank drives producing a circular translational movement of the movable disc in the housing same eccentricity existing support of the movable disc in the housing, with drive elements for the movable disc, being between the spiral bands of the two discs regardless of the respective position of the movable disc only a small, but constant game is available, and with at least one on the one hand on the housing and on the other hand, sealing bellows attached to the movable disc.

2,9851 / Π750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

In such vacuum pumps, in particular in such a vacuum pump with a single movable spiral belt, as in the aforementioned patent, has the movable disc carrying this movable spiral belt on its outside a central organ in the form of a sleeve for connection to the three crank mechanisms, which is from the sealing bellows is enclosed, while the stationary disk with its stationary spiral belt engaging in the movable spiral belt forms part of the fixed housing.

The applicant has now found that this arrangement gives very good results as long as the constant play, which is provided between the spiral bands of the two discs, is not very small, which corresponds to the areas of application of such a pump in which the requirements on the desired negative pressure are not very high. However, such an arrangement is disadvantageous in that it increases the risk contains inconvenient contacts if the constant play is chosen to be very small in order to achieve a high suction power must become.

This disadvantage is probably due to that of the movable The movement given to the disc by the crank drives is carried out via a central organ, which can cause blows, whose amplitude, which may still be small in the center, increases towards the edge of the disk and thus the risk is more inconvenient Brings contacts.

209 «K1 / 0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

The invention has therefore set itself the task of a vacuum pump of the aforementioned type, which works completely dry with a precisely circular translational movement and absolutely tight is to be trained in such a way that with a simple and robust construction, a high level of accuracy in operation and give excellent performance without the risk of contamination, leakage or excessive heating or plague eating caused by faulty contacts with perfect suction and discharge conditions.

Such a vacuum pump according to the invention is identified essentially in that the movable disc is connected at its edge directly to the three crank mechanisms, while a fixed central shaft connects the fixed disc to a fixed lower part of the housing and is surrounded by a sealing bellows, one end of which with the movable disc and the other end with the lower part connected is.

This arrangement eliminates every central intermediate organ in the transmission of motion, which causes blows could be caused, which intensify towards the edge. In contrast, the utmost accuracy, which is already realized by the arrangement of the crank drives in the edge area of the movable disc, only reinforced, the closer you get to the center. In this way a very precise movement is achieved with very little play between allows the spiral belts without the risk of contact, so that the pump has a high suction power as a result can result.

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

This result is achieved in particular in that a stationary housing is provided, which is preferably consists of a single part, the middle part of which is enclosed by the sealing bellows and the wall part of which has three recesses has, in which the drive shafts are properly stored. This arrangement results in a very stiff unit, as a result of which any deformations or deflections as a result of the pressure effect in the central delivery area of the fixed spiral belt can be prevented and whereby a very precise sequence of the circular translational movement is made possible is generated by the three crank mechanisms, which cannot bend due to their perfect storage.

The suction and delivery conditions for the pump medium are also improved by the fact that a fixed central shaft is provided, which is surrounded by the sealing bellows and carries the fixed spiral band. In particular, can for the suction in a simple manner the annular space between the fixed central shaft and the sealing bellows surrounding it be provided, while a delivery line with its valve without difficulty in the axis of this fixed central shaft can be trained. A vertical arrangement is particularly favorable, since it facilitates cleaning and removal any liquid that could cause condensable vapors within the spiral belts is relieved.

According to a further special feature of the invention, devices are provided which switch off any different dilation, which could change the operating clearance between the active parts of the pump.

/ 0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, TheaterpHz 3

For this purpose, the housing, the active pumping elements and the mechanical movement transmission elements are preferably made Made of materials that have the same coefficient of expansion and the same thermal conductivity. It is also provided that when the pump is put into operation, devices by means of which a cooling medium ^ is brought into circulation in such a way that the thermal energies generated by the pumping work and the mechanical movement are uniform be distributed to the housing, the active pumping organs and the motion transmission organs. Under these conditions the puncture play of the pump remains constant, both during operation and every time it is started up, even if this is done Commissioning takes place at different ambient temperatures.

It is clear that with such a pump, in which the active pumping elements cooperate without mutual friction, the thermal energy generated remains below that which is generated in a conventional pump, for example a vane pump in which the friction causes a very strong heating, which is intensified by the thermodynamic pumping effect will. As a result, the pump according to the invention can operate at high speeds, which is one of the factors for increasing performance forms.

In one embodiment of the invention, the vacuum pump has a single effective pumping element with a single spiral band on the fixed disc and a single spiral band the moving disc.

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

A variant of the invention, through which a higher suction power is achievable, has two effective pumping elements, the movable disc consists of two parts, the spiral bands facing each other with some distance and between which the fixed disc with a spiral band each side is arranged in such a way that its spiral bands cooperate with the spiral bands of the two-part movable disc, while the two-part disc is connected to a single drive mechanism and the entire effective Area of the pump is sealed from the outside air by a single sealing bellows.

With this arrangement, the two spiral belts through which the pump medium initially passes do not have a central bead. through which the medium receives a centrifugal effect, whereby at the low pressures the pumping capacity of the entire Pump is improved. These spiral belts are practically not subject to any heating, as they only work at low pressures.

One can see that the construction with a fixed Central shaft an extremely simple design of this version with two fixed spiral bands for the only one Drive device results in a single sealing bellows.

A type of pump with a single pair of spiral belts can, as has been found, generate a limit value for the vacuum which is close to 1/100 Torr, measured according to MAC-LEQD, with direct delivery of an atmospheric pressure of 760 Torr. Under the same conditions, the limit value for the vacuum is reached at

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

a type of pump with two pairs of spiral belts has a value that is less than 1/1000 Torr. Such results were for example achieved with a pump, which had a throughput of 60 mr / h, ran with a number of revolutions of 1460 t / min and had a functional play of 8/100 mm,

In another variant, especially in the case of a very small version, a dry pump is used in a single unit of the usual type, for example a diaphragm pump or the like, with a vacuum pump according to the invention with a pair of spiral belts combined with or without a central bead.

The diaphragm pump is on the pressure side directly with the free air connected, while it is connected on the suction side to the central delivery of the spiral bands, the one located on the edge Suction area is connected to the room that is to be pumped dry. The work of the second active pumping organ, which is formed by the pair of spiral bands that suck in directly from the space to be pumped out, enables a significant Improvement of the vacuum limit in this room. This result is achieved in that the suction power, i.e. the The effectiveness of this pair of spiral belts rises sharply from the level of the low pressures to which the only diaphragm pump applies can be achieved by creating a first preliminary vacuum with a value of a few Torr. This increase in performance results from the strengthening of the resistance to leakage losses through the puncture play of the spiral bands according to the falling pressure.

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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Due to the low power that is required once, to drive these low volume pumps, and due to the significant work on the part of the diaphragm pump to achieve this the preliminary vacuum will result from the thermodynamic The amount of heat resulting from the pumping action of the spiral belt pair is negligible. In this way the stiffness of the whole can be reduced easily maintained and avoid any differential dilation during operation. A simple fan which is driven by the pump drive at the same time and is built into the entire unit, enables the required Cooling and stabilization of the temperatures of the mechanical organs and the inner part of the housing.

Such an operation without circulating coolant in the Contact with the spiral ribbons enables arrangements which result in both a downsizing of the whole and a high one Operational safety lead. In particular, the outside of the movable disc is directly connected to the movable end of the sealing bellows connected, while a sealing bell is attached to the edge of the inner surface of this same movable disc. These Bell, which has no central opening, covers the entire fixed disk with its spiral band, which is in turn attached to the end of the central shaft enclosed by the sealing bellows.

This design is particularly noteworthy as the dilatations that arise as a result of accidental heating could have an effect in the direction of an increase in the lateral functional play. Every dilation of the central

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, TheaterpSicitz 3

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shaft to it, the fixed spiral band from the movable one To push the spiral band away in the axial direction of the pump. To this In this way, a significant puncture safety is achieved with spiral bands that work without direct liquid cooling can.

It therefore follows that the last-mentioned variant is particularly useful for such applications in which the use the deformable membrane is compatible with the pump medium and the quality of the vacuum to be achieved, so that a simple and space-consuming solution for. Vacuum pumps results whose throughput need only be low and is, for example, about 15 r / h.

This combination of a diaphragm pump with one or the other type of spiral belt allows for example for air a functional play of about 6/100 mm and a speed of 1460 t / min measured a vacuum limit value of 1/1000 Torr the MAC-LEOD method.

7 Π 9 η 5 1/0 7 5 0

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

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Below are some embodiments of the invention explained in detail with reference to the accompanying drawings; show it:

Figure 1 is a vertical section along the line I-I of Fig. 2 through a vacuum pump with a single pair of spiral belts;

Figure 2 is a section through Figure 1 along the line H-II, the spiral bands immediately before The end of the suction cycle are shown;

2a shows a representation of the spiral-shaped one corresponding to FIG Ligaments immediately at the end of displacement and at the moment of full suction;

FIG. 3 shows a schematic representation of the vacuum pump according to FIG Figures 1 to 2a showing an oil circuit for cooling and temperature equalization of the effective pump parts as well as for lubrication of the Motion transmitter parts;

Figure 4 is a vertical section through a modification of a Vacuum pump with two pairs of spiral belts along a line IV-IV of Fig. 5 in another Angular position;

FIG. 5 shows a horizontal section through FIG. 4 along the line V-V;

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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FIG. 6 shows a further variant of the vacuum pump according to the invention with a pair of spiral belts and a diaphragm pump as a cut through Pig. 7 along the line VI-VI; and

FIG. 7 shows a section through FIG. 6 along the line VII-VII, the spiral bands in their the position corresponding to the end of the suction cycle and half of the displacement cycle are located immediately.

The illustrated in Figures 1, 2, 2a and J 'vacuum pump according to the invention with circular translational movement of the lubrication-free and completely sealed moving parts has a fixed housing 10 with a fixed disc 13' * which carries a spiral band IJ on one side. Opposite this fixed disc 13 * is a movable disc 2J 'which has a spiral band 2j5 with the same angular amplitude as the band IJ of the fixed disc Ij' and is in engagement therewith. To connect the movable disc 2J ¹ to the housing 10 and to support it, a mechanism is provided which consists of at least three crank drives 20 of the same eccentricity E, which are synchromically coupled to one another to achieve a circular translational movement of the movable disc 2 J ¹ with respect to the stationary one Housing 10 to generate during operation of the pump.

209851/0750

Andrejewski, Honlce & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

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Pur the actual drive of the movable disc 25 are Drive members 19 are provided, which give it the movement and which are to be described in detail below. There is a little between the spiral bands Ij5 and 25 constant play is provided, which remains constant regardless of the respective position of the movable disc 25 *. A sealing bellows 11 is at its one end 28 on the movable disc 25 'and at its other end 50 on one Lower part 10 "of the" fixed housing 10 is attached.

The movable disc 25 'is directly on its edge with three Crank drives 20 connected, while a fixed central shaft 10 'the fixed disc 15' with the fixed The lower part "10" of the housing 10 connects and is surrounded by the sealing bellows.

This sealing bellows 11 made of metal, which is the flawless Sealing of the system realized is against any torsional effect occurring during operation or accidentally protected by the kinematics of the drive system with three synchronized crank drives 20.

As a result, the length of the sealing bellows is under observation with the straight lines connecting the operating eccentricity, the service life of this organ in a vacuum pump is practically possible unlimited.

In the illustrated embodiment, the pump has in particular.a single pair of spiral ribbons 15 and

20985Ί / Π750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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It has an axis A. Its fixed housing 10 is in one piece and is composed of the central part or the hollow shaft 10 ', the lower part 10 "and a wall part 10'". The latter surrounds the sealing bellows 11, which in turn surrounds the hollow shaft 10 '.

The wall part 10 '"has three offset from one another by 120 ° Recesses 12; On the central shaft 10 'of the housing 10 is the fixed disk 10 'by screw bolts 14 with insertion a static seal 15 screwed tight. The three Housing parts lying in the vertical axis of the recesses 12 are machined in such a way that they have guide bearings 16 and 17 as well as an axial stop 18, which serve for the unconditional alignment of each of the three shafts 19, their crank mechanisms 20 a transmission part 21 via ball bearings ^ 22 with a Drive eccentricity E.

The movable disk 23 ′ having the spiral band 23 is firmly connected to the transmission part 21 by a series of screw bolts 24. The movable disk 2J ¹ has reinforcing ribs 25 on its upper side. to prevent deformations due to pressure.

There are balancing weights 26 on the shafts 19 and on the cranks 20 further balancing masses 27 wedged. These different Masses are calculated and arranged in such a way - that a correct static and dynamic balancing of the organs in the circular translational movement is realized.

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

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At its upper end, the sealing bellows 11 is welded to a bell 28, which is screwed to the transmission part 21 via screw bolts 2k and thereby compresses a static seal, which in this way ensures the seal between this bell 28 and the spiral-shaped movable band 23.

The sealing bellows 11 are attached to an annular disk with its lower end 30 welded on, which in turn uses countersunk screws 51 with the insertion of a static seal 52 with the housing is screwed.

In addition, FIG. 1 shows the suction line 33 of the pump, which is connected to the housing 10, and the pressure line 35 * which has a valve Jk and is part of an organ 36. This organ runs through the central ^{shaft 10 f of} the housing 10 and is firmly connected to this with the insertion of seals 37 and 38, these seals being intended to prevent the outflow of cooling oil to the outside. As the figure shows, the line 35, the valve 3 ^ and the member 36 are arranged coaxially to the axis A of the pump.

The space to be pumped out is connected to the suction line 33 of the housing 10 connected. When the pump is started up, the gaseous medium to be pumped becomes translational as a result of the circular shape occurring rolling motion of the movable spiral Band 23 opposite the fixed spiral band I3 continuously and progressively compressed. As a result, this gaseous medium is sucked into the annular space, which through the

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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Inner wall of the sealing bellows 11 and the bell 28 and the outer wall of the central shaft 10 ^! of the housing 10 and is limited by the fixed spiral band 13, while then the same gaseous medium is discharged through the valve 34 and the line 35.

The way in which the two spiral bands 13 and 23 are punctured corresponds to a multi-stage pump and is explained below of Figures 2 and 2a described in detail which correspond to the different positions of these parts.

Each rotation of the spiral band, which is determined by a sequence of 360 ⁰ , corresponds to a compression level.

With each circular translation stroke, the movement causes each of the contact points (with little play) in each step realizes its own progressive compression, whereby the enclosed volumes remain permanently separated from each other, and through as many partitions as the pump has steps.

In particular, it can be seen from Figure 2 that the spiral bands I3 and 23 are shown in a position which precedes the end of the intake stroke. If the position of the spiral bands corresponds to this end of the intake stroke, the two enclosed volumes V ^ are subject to a first compression after a first circular translation stroke, which reduces _{them to the two volumes V 2.} These are compressed for the second time after a second cycle and combined to form a volume V, which is the final pressure during the third cycle

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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is subjected in order to be expelled as a whole with little loss through the valve ~ 5k , the spiral-shaped bands then being in a position immediately before the end of the exhaust stroke and at the end of the intake stroke, as shown in FIG. 2a.

The thick beads at the inner end of each spiral band 15 and 25 allow apart from the formation of an outwardly open cavity 4j5 respectively. 45 for cooling due to their thick design, the reduction of radial and lateral leakage points in the area in which the compression is strongest. For an equal functional eccentricity E, the common volume of the final compression is also V ^. (FIG. 2), the larger the two bulges are, between which the volume is enclosed, whereby the choice of an optimal dimension for the outlet opening J> k is particularly facilitated.

It can be seen that every room of the pump in which the vacuum is created is completely affected by the external environment and is at the same time separated from a cooling circuit, which is also used for lubrication and below with reference to FIG should be explained in which the oil flow is shown schematically.

In the lower part of a casing 39 * which contains the entire pump, without being functionally connected to it, there is an oil reservoir in which a pump 40 is immersed which is driven by one of the shafts 19. That in the annular space 41 between the outer wall of the part 36

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

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and oil pumped into the inner wall of the central shaft 10 ' enters a cavity 42 in the disk with the fixed spiral band 15 and rises from this into the central bead this fixed spiral belt 13 formed cavity 43. From there it flows through the pipeline 44 and becomes the extension 45 in the central bead of the movable spiral belt 23 injected. As a result of the movement, after wetting the outside of the spiral belt 23, the oil is energetically along the casing 39 thrown away. This way the whole mechanical part lubricated by projection and most of the oil trickles down along the casing 39 to after Cooling to return to the oil reservoir surrounding the pump 40.

It can be seen that, if the pump is large enough, the cavities 43 and 45 are wholly or partially up to the spiral bands can extend.

It will be understood that as a result of the intense circulation of the Cooling oil, in particular in the cavities 43 and 44 located directly on the outside of the central areas of the spiral bands, in which the effect of the final pressure generates the greatest heat development, and through the subsequent circulation this Oil both in the interior of the middle shaft.10 'and on the outside of the disks 13 * and 23' of these spiral bands 13 and 23 and the entire housing 10, a temperature equalization is achieved in all organs of the pump, which is within the on the Function of the pump completely uninvolved casing 39 are arranged.

2Ö985V 0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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In this way, any different dilation between these same organs avoided, so in all speed ranges the same functional play between the spiral bands can be maintained. This result is a crucial one Factor in terms of operational safety and durability of excellent industrial performances, which are achieved by these devices.

The pump drive, not shown in the drawings, takes place either directly or indirectly via one of the three vertical ones Shafts 19, which for this purpose are brought out of the casing are.

A second shaft 19 can directly drive the element 40 which is to circulate the cooling medium. In this context, it should be noted that for small pumps with a pump volume of 10 to 15 nr / h, ^{air can be used as the} cooling medium, which is blown through passages provided for this purpose by means of a centrifugal fan. In addition to the use of oil, which is used to cool the spiral belts and at the same time to lubricate the mechanical part, if grease is used for lubrication, the cooling can be connected to a water inlet, with the movable spiral belt in this case being sealed at its top Has cavity, which is connected to the inlet of the fixed spiral belt on the one hand and the drain on the other hand via two hoses.

2098 51 / Π750

Anclrejewskl, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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In the modified embodiment shown in FIGS the arrangement of the embodiment described above is analogous to the invention, but this pump has two effective pumping organs each with a pair of spiral bands.

50 is the construction of the vacuum pump shown in FIG very similar to the embodiment according to FIG. 1, it contains but once a first pair of spiral bands 46 and 47 without a central one Bead (Fig. 5) and on the other hand a second pair of spiral bands 13 and 23 with outwardly open central hollow beads, analogous to the pair of spiral belts of the embodiment according to 1 to 3, a section through FIG. 4 along the line a-a corresponding to the angular position from FIG.

In the case of the pump according to FIGS. 4 and 5, this is limited Primary vacuum improved in that the medium to be pumped is conducted into the first pair of spiral belts 46 and 47 without a central bead will. In doing so, the medium is through the opening 33 via the inner areas 48 and 49 sucked in and through the edge areas 50 and

51 discharged, which directly into the suction areas of the two Spiral bands 13 and 23 open with a central bead, which as in the embodiment according to 1 and 2, the medium is directly in Free discharge.

The two spiral bands 46 and 47 have a generated volume, which is selected to be very close to that of the spiral bands 13 and 23. At the start of pumping, the volume sucked in through the line 33 is pressed in the spiral bands 46 and 47 from the inside to the outside, as with the spiral belts 13 and 23, a constant separation between the enclosed volume and the suction and

209851/0750

Andrejewslci, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz

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Ejection areas takes place. The unconditional equality of the volumes generated by each of the pairs of spiral bands implies that practically in every initial pumping phase the compression due to the action of the spiral bands 46 and 47 remains very low and consequently their warming can be neglected.

However, while the suction pressure in areas 48 and 49 is small is, i.e. is close to 1 Torr, the performance of the Spiral bands 46 and 47 grow, making the entire pump a limit vacuum of 1/1000 Torr, which is due to the fact that the resistance to losses due to the puncture play increases sharply according to the decreasing pressure.

The performance of the pump according to Figures 4 and 5 result from the fact that the molecules of the medium to be pumped at low Pressures are accelerated, this acceleration originating from the volumetric effect on the one hand and from the on the other Centrifugal action caused by the rolling in circular translational motion of the movable spiral belt 46 on the fixed spiral belt 47 is generated. The two spiral bands 46 and 47 produce practically no heating, since they are only effective at low pressures, so that they give good results can result in a functional play which is greater than in the case of the spiral belts 13 and 23.

As Figure 4 shows, the rolling of the movable spiral belt 23 in circular translational motion on the stationary Spiral belt 13 by the same mechanical device caused, as described with reference to FIGS. 1 and 2. This fixed spiral belt I3 belongs to one

20985WG75G

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

The same disk-shaped part IJ ¹ , in the lower part of which the second fixed spiral band 47 'is worked out, in which the second movable spiral band 46 engages. The two disks 23 * and 26 'of the movable spiral belts 23 and 46 are connected by the ring piece 52, which replaces the bell 28 of FIG.

The other facilities of this construction such as cooling, static seals, etc. are practically the same Designed in the same way as in the construction according to FIGS. 1 and 2.

One can see the simplicity achieved in this construction notice that the two spiral band pairs with a single Control device and a single Abdichtbalg work.

Another variant of the vacuum pump according to the invention is shown in Figures 6 and 7, it is in particular, if not exclusively, a small version. This perfectly dry-working pump unit consists of a membrane pump P, which supplies the medium via line 53 releases the atmosphere and via line 54 and channel 35 sucks in the annular space between the interior of the sealing bellows 11 and the central shaft 10 'of the housing 1.0. In this annulus the outlet opening 34 of the fixed spiral belt 13 opens and the movable spiral belt 23, the suction effect of which is limited by the bell 28. This suction space is about the im

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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Inside the central shaft 10 'and the part 14 formed line 33 connected to the space to be pumped empty. It serves the part 14 for fastening the fixed spiral belt 13 on the central shaft 10 '.

The membrane pump P, whose pump output is due to the changing Deformation of an elastic wall is achieved, which is subject to an eccentric action on the part of the drive shaft, is a dry working, completely dense organ, the structure of which is known per se and therefore not in detail needs to be described. Its best performances for creating a vacuum are at a limit pressure of a few Torr.

The spiral bands 13 and 2J shown in FIGS. 6 and 7 are specially designed in that they have different beads. In this way, thanks to this special design, a pair of spiral belts can easily be provided for this small construction, which works practically in the same way as the spiral belts shown in FIGS. In FIG. 7 it can actually be seen that at the end of the compression the entire volume sucked in is completely expelled through the opening y \ with the slightest loss due to the functional play. Thanks to its thick bead, the fixed spiral band IJ can be easily fixed with the insertion of the static seal 15 on the central shaft 10 'by screwing a part 14 with a thread 14' into the central shaft 10 'and with its smooth part as a centering on the Center shaft 10 'is used. This part 14 is hollow and extends the

209851/0750

Andrejewski, Honlce & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

Bore of the central ^{shaft 10 1} , so that in this way the line 33 is created again, which connects the suction space of the spiral belts with the space to be pumped empty.

As already mentioned above, one can use the same arrangement the two spiral bands, with different beads 13 and 23 replaced by two spiral bands without a bead, which the have the same course as is shown for the spiral bands 46 and in FIG. It can be seen that the Arrangement according to FIGS. 6 and 7 suck in these beadless spiral bands at the edge and eject them towards the central area.

The bell 28 is inserted with the static seal 29 by means of screw bolts 24 which are attached to the three ring segments 26 act, firmly pressed against the inner surface of the disk 23. The connection piece welded to the end of the sealing bellows 11 is in turn with the insertion of the static seal 29 'means Screws 58 screwed onto the outer surface of the disk 23 'of the movable spiral belt 23. At the fixed end is the sealing bellows 11 is welded to a ring 30, which in turn is screwed onto the housing with the insertion of the static seal by means of screws 3I.

The disc 23 ', which is small in size, has three In each case by 120 ° offset from one another extensions 23 "for receiving the ball bearings 22, in which the eccentrics 20 of the Waves I9 run around. As a result, the three eccentrics 20 drive the movable spiral belt 23, 23 ', 23 "directly in a positive direction circular translation movement with an eccentricity E.

209851/0750

Andrejewski, Horske & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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With this construction, the elimination of the direct cooling of the effective pump part consisting of the spiral bands allows To make arrangements which on the one hand to a reduction of the dimensions and on the other hand to an operational safety in the event of a dilatation as a result of accidental heating, the housing 10 preferably being formed in two parts is to allow easy assembly and adjustment of the various organs.

For this purpose, the housing 10 has a first ^one- piece part consisting of the central shaft 10 1, the lower part and its edge extension 10 ", as well as a second part 10 ^IH , which is aligned and fastened on the machined surface of the edge part 10" by means of screws 59 (Fig .7).

This second housing part 10 ^m has three cylindrical, each offset by 120 ° to each other'Ausnehmungen, the angular contact ball bearings 16 and 17, which serve for guidance and as an abutment for the forced alignment of each of the shafts I9, on which the eccentric 20 for the Drive of the movable spiral belt 23 and on the other hand the masses 26 and 27 are keyed, which are used for static and dynamic balancing of the movable part.

The drive can take place in the manner shown in FIGS. 6 and 7, namely by direct coupling of one of the shafts 19 with an electric motor 55 »with a second shaft I9 at the same time directly drives the diaphragm pump P. At the end of the third shaft 19 you can arrange a small fan that is in the

209851/0750

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3

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Figures, however, is not shown and serves, if necessary, the temperature of the mechanical part and the Housing parts 10 "and 10 ,!" to lower and stabilize.

/ ■

With this pump, the diaphragm pump is at the suction end and at the pressure end Valves are used and an additional pressure valve 34 can be provided when assembling the spiral belts 15 and 2; 5.

These various inventive necessarily dry and Sealed vacuum pumps are used in particular in the field of atomic technology, in the manufacture of electronic devices Tubes and components, in laboratories and in general in those cases in which a vacuum without any can be found with the highest level of safety Pollution must be generated.

/ 0750

Claims (18)

Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3 - 28 Patent claims: ^/ \ 1 / Vacuum pump with circular translational movement of the effective parts moving without lubrication under complete sealing, consisting of a stationary housing with a stationary disk with a spiral band on at least one side, a movable disk opposite this stationary disk, supported in the housing and also with at least one spiral band with the same angular amplitude in engagement with the band of the stationary disc, with a support of the movable disc in the housing consisting of at least three synchronously running, a circular translational movement of the movable disc in the housing controlling crank drives of equal eccentricity, with drive elements for the movable disc, wherein There is only a slight but constant play between the spiral bands of the two disks regardless of the respective position of the movable disk, and with one on the one hand on the housing and on the other sealing bellows attached to the movable disc, characterized in that the movable disc (23 ¹ ) is connected at its edge directly to the three crank mechanisms (20), while a fixed central shaft (10 ¹ ) connects the fixed disc (I3 ¹ ) with a the fixed lower part (10 ") of the housing (10) and is surrounded by a sealing bellows (11), one end of which is connected to the movable disc and the other end of which is connected to the lower part. 209851/0750 Changrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3 - 29 - 2. Vacuum pump according to claim 1, characterized in that they have a single effective pumping element with a single spiral band (15) on the fixed disc (I3 ') and a single one Has spiral band (23) on the movable disk "(23 '). 3. Vacuum pump according to claim 2, characterized in that the two spiral bands (13 * 23) have an outwardly open hollow bead (43, 45) at the inner end. 4. Vacuum pump according to claim 1, characterized in that it has two effective pumping elements and the movable disc consists of two parts (23 ¹ , 46 '), the spiral belts (23, 46) of which are "opposite one another at some distance and between which the fixed Disc (I3 ¹ ) with a spiral band (13, 47) on each side is arranged in such a way that its spiral bands cooperate with the spiral bands of the two-part movable disc, and that the two-part disc is connected to a single drive mechanism (19 * 20) and the entire effective area of the pump is sealed off from the outside air by a single sealing bellows (11). 5. Vacuum pump according to claim 4, characterized in that the spiral bands (46, 47) of one active pumping element (46 ', I3 ¹ ) have no central bead and suck in from the center, while the spiral bands (13 * 23) of the other active one Pump elements (13 ¹ , 23 ¹ ) have an outwardly open central bead (43, 45) and suck in from the edge. 6. Vacuum pump according to one of claims 1 - 5 * characterized in that that the pump as a whole is functional from it 209851/0750 Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3 - 30 - independent jacket (39) serving only cooling purposes is enclosed and this has a cooling oil reservoir, from which the cooling oil is conveyed by means of a pressure conveyor (40) through a channel (41) in the fixed central shaft (10 ¹ ) to a cavity (42) in the fixed disc ( Ij '), from where a recess (43) in the fixed spiral belt (13) and from this via a line (44) to a recess (45) in the movable spiral belt (23) can be fed. 7. Vacuum pump according to claim 6, characterized in that the recesses (43, 45) of the two spiral belts (13 * 23) outwardly open depressions exist. 8. Vacuum pump according to claim 7> characterized in that the outwardly open recesses (43, 45) in a central bead of the spiral bands (I3, 23) are formed. 9. Vacuum pump according to one of claims 1-8, characterized in that the suction opening (33) of the pump is ^{in communication with the annular space between the fixed central shaft (10 1} ) and the sealing bellows (11) surrounding it. 10. Vacuum pump according to one of claims 1-9 *, characterized in that a pressure channel (35) equipped with a valve (34) is formed ^{in the stationary central shaft (10 1).} 11. Vacuum pump according to one of claims 1 to 10, characterized in that the fixed disc (13 ^f ) is arranged closer to the lower housing part (10 ") than the movable disc (23 ¹ ). 209851/0750 Andrejewslci, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 3 12. Vacuum pump according to one of Claims 1 to 10, characterized in that the fixed disc (15 *) and the movable disc (25 *) are arranged relative to one another in such a way that the movable disc is between the fixed disc and the lower housing part (10 "). lies (Fig. 6). 13. Vacuum pump according to one of claims 1-12, characterized in that the fixed spiral band (I3) is mounted on the central ^{shaft (10 1} ) in such a way that the side part delimiting the width of the spiral band points to the lower housing part (IO ") . 14. Vacuum pump according to one of claims 1-13 *, characterized in that it is followed by a second pump, for example a diaphragm pump (P) . 15. A vacuum pump according to claim 14, characterized in that the helical strips (Ij5 * 23) do not have a central ridge. 16. A vacuum pump according to claim 14, characterized in that the fixed spiral band (I3) having a thick central ridge and the movable spiral belt (23) a weak or no überheupt Γ "telwulst. 17. Vacuum pump according to one of claims 14-16, characterized in that the spiral belts (13 * 23) suck in from the edge and release in the central area. 209 H 51 / Π750 ! BAD ORIGINAL Andrejewski, Honke & Gesthuysen, patent attorneys, 4300 Essen, Theaterplatz 18. Vacuum pump according to one of claims 14 - 1?> characterized in that the central shaft (10 ') serves as a suction channel (33) has serving axial bore and the delivery of the pump medium via the annular space between the central shaft and the sealing bellows (11) surrounding it (Fig. 6, 7) Patent attorney. 209851/0750 eerseite