WO2004088141A2

WO2004088141A2 - Oscillating piston pump

Info

Publication number: WO2004088141A2
Application number: PCT/EP2004/050435
Authority: WO
Inventors: Sabine Meier; Sven Engelbrecht; Uwe Drewes; Rudolf Bahnen
Original assignee: Gebr. Becker Gmbh & Co. Kg
Priority date: 2003-04-02
Filing date: 2004-04-02
Publication date: 2004-10-14
Also published as: KR20050114270A; JP2006522265A; EP1608874A2; WO2004088141A3; US20070104600A1

Abstract

The invention relates to a pump (1), such as a vacuum pump or a compressor, comprising a pump housing (18) and at least one pump piston (2, 3) that moves along a circular path. In order to embody a novel pump of said type, the pump piston (2, 3), which is optionally coupled in a rigid manner to one or several additional pump pistons (2, 3), moves about a swivel pin (5) so as to oscillate along a trajectory that is correspondingly provided with two reversing positions. Optionally compressed or pressurized medium is discharged via a discharge valve (8) while an intake valve (9) opens during a movement from one reversing position to the other, whereupon the medium is discharged at a given pressure end of the pump piston (2, 3) while being sucked in at an intake end thereof during a pressure build-up.

Description

pump

The invention relates to a pump with at least two pump pistons moving on a common circular path.

Pumps, so-called vacuum pumps, are already known in various configurations. For example, continuously rotating radial compressors are known, but also reciprocating movements, oscillating movements, and piston compressor pumps that execute them.

In contrast, the invention is concerned with a novel pump with at least one pump piston moving on a circular path and a pump housing, the pump piston, possibly rigidly coupled with one or more further pump pistons, oscillating about an axis of rotation on a movement path having two reversing positions , whereby medium is discharged further via an outlet valve and an inlet valve is opened in the course of a movement from one reversal position into the other reversal position, after which a discharge is discharged on a respective pressure side of the pump piston in the course of a pressure build-up and on a suction side of the Pump piston suction of the medium takes place.

With such a pump, higher performance values can be achieved compared to radial compressors. The pump is comparatively simple

The subject matter of the further claims are explained below in relation to the subject matter of claim 1, but can also be of importance in their independent formulation. In one embodiment it is provided that the inlet valve is overflowed during the movement from one reversing position to the other reversing position.

The pump pistons move in a pump room. The pump chamber is formed radially on the inside by an inner wall which is preferably designed to be rotationally fixed with the pump pistons. As far as several pump pistons are provided, it is preferably also the connecting wall between two or more pump pistons. The housing wall which delimits the pump space radially on the outside is suitably designed to be fixed. The inlet valve can be formed in the pump chamber floor and / or in the pump chamber ceiling and / or in the outer housing wall and / or in the housing partition.

The pump chamber is limited in the direction of movement of a pump piston - on both sides - by a fixed housing partition. In the case of two pump pistons, the housing partition walls separate the two pump chambers. This housing partition allows the pressure to be built up - to a desired extent - when the pump piston is moved into the reverse position. The outlet valve is preferably designed as a check valve. The outlet valve can be formed in the housing partition and / or in the pump chamber floor and / or in the pump chamber ceiling and / or in the outer housing wall.

The pump can be driven, for example, by an electric motor. But also by another engine. In detail, as explained below, it is advisable to carry out the power transmission by means of a crankshaft. It can also be an electric motor that directly generates the back and forth movement. In more detail, the electric motor can be a conventional universal motor. But it can also be a so-called reluctance motor. For the immediate generation of the back and forth movement, for example, is suitable. a stepper motor. In addition, an electrical or electromagnetic spring / mass system can be provided for the drive. Mass balancing must be ensured.

The arrangement of the axes of the drive and pumps is important here, for example if two pumps are connected with a central drive. The reverse positions of the pistons of both pumps are in phase. In the intermediate positions, however, there are different angular positions and a phase deviation dependent on the position of the center points. This can be minimized by targeted height adjustments between the drive axis and the pump axis.

When the drive force is transmitted to the pump by means of a crankshaft, it is also advisable to drive two or more such pumps at the same time. The crankshaft enables the engine, in particular the electric motor, to move continuously. The angle-limited back and forth movement of the pump or the pump pistons is generated by means of connecting rods acting on the crankshaft in a manner known per se, comparable to an Otto engine or a diesel engine in the automotive field. The two such pumps, which are preferably driven via the same crankshaft, then suitably move in opposite directions.

Particular attention is paid to the sealing of the pump pistons in the pump housing. First of all, this is how it works, for example in the outer peripheral area, but also in the inner peripheral area, for example in cooperation with the housing partition, on the other hand, is fixed so that the effective gap length is formed with a length such that the length of the gap alone provides a suitable seal. In any case, with a sufficiently small gap, preferably in the hundredth of a millimeter range, in any case not significantly exceeding a tenth of a millimeter range. Gap dimensions in the range of a few hundredths of a millimeter are further preferred.

Furthermore, there or. However, separate sealing lips can also be used on one of the several of the sealingly interacting surfaces and / or in the course of operation of the pump a coating is applied to one of the surfaces that interact with one another.

The reciprocating movement, oscillating movement, of the piston is carried out in such a way that the housing partition is preferably not touched. A few tenths of a mm or a few percent, or preferably a few tenths of a percent, based on the total range of rotation angle of the pump pistons when moving from one to the other reversal position, the respective pump piston stops in the reversed position in front of the house partition.

In further detail, the housing partition wall can be designed such that the distance to the associated piston surface is constant in the circumferential angle range of greatest approximation via a radial. However, it can also be selected (straight surface) so that there is a wedge-shaped, (radially) outwardly widening gap between the assigned surfaces in the position mentioned. The range of rotation of a piston is preferably approximately 90 °. However, it can also go beyond this, for example up to + / - 30 °, in which case corresponding intermediate stages such as 95 °, 100 °, 105 °, 110 ° etc., as well as angle ranges still in between, must also be included. The same applies to values below 90 °. In this way you can achieve a coordination between the respective loading volume and the piston size.

The pump pistons themselves preferably consist of a light material such as aluminum. It is more preferably an extruded profile (although this is not bound to the material aluminum). The construction is designed in such a way that the large masses are pushed radially outwards as far as possible with respect to the axis of rotation of the pump pistons. Overall, the moving masses should be as small as possible due to the moments of inertia, which is why a lightweight material such as aluminum is recommended for the moving masses.

When designed as an extrusion profile, the pump pistons have corresponding cavities. These can be closed with a lid at the top and bottom.

The height of the pump pistons or their extension in the axial direction of the common axis of rotation preferably corresponds approximately to a diameter from the axis of rotation to the outer circumferential wall of a pump piston. The aim is to minimize the column.

An inlet valve can be designed as a simple permanent opening. For example in the form of a hole or in the form of a groove. In addition, it can also be designed as a check valve (e.g. ball valve). In the pump with two pump pistons, four outlet valves and two inlet valves are provided. However, four inlet valves can also be provided if, for example, the other two are each activated.

Further alternatively, the inlet valve and the outlet valve can be assigned to the same end region of the movement path, that is to say in detail to a respective retracting position. Inlet valve and outlet valve can be provided adjacent to each other. In this regard, it proves to be advantageous if the inlet valve and the outlet valve are arranged in the same housing partition.

The inlet valve and / or the outlet valve can in this case be formed from a stamped or bent sheet metal part, with a closure plate assigned to a valve opening and an adjoining bend section. In this regard, a sheet steel part, in particular formed from spring steel, can be provided. In this case, the inlet valve and / or the outlet valve further preferably has closure plates and bending sections which merge into one another at the same level. Accordingly, these are preferably arranged offset from one another with respect to a plane. Furthermore, an inlet valve and / or an outlet valve has a mounting foot, which is, for example, clamped, in particular clamped in the area of the housing partition. This bracket foot also merges, at least partially, preferably at the same level into the bending section.

For the sealing closure of the inlet valve and / or outlet valve, the closure plate preferably lies on a sealing support which is clamped between the valve and the associated housing part. It can also be glued on. In the case of the clamp bracket, this is preferred achieved by means of a clamping part or a pressure part. The support can be formed from a plastic part, for example an elastomer.

The longitudinal extension of the inlet valve and / or the outlet valve extends in the direction of the axis of rotation of the pump pistons, in particular in the configuration of the valves in the form of stamped or bent sheet metal parts, which essentially consist of a mounting foot, a bending section and a locking plate. Thus, a plurality of outlet valves can also be arranged next to one another in the direction of the axis of rotation. It is also conceivable here to arrange a plurality of inlet valves side by side in the direction of the axis of rotation.

A parallel positioning of a spring-loaded inlet valve to the outlet valve in the housing partition proves itself in relation to a reduction in the power consumption during suction, i. H. when refilling the pressure chamber, as advantageous. This reduces the pressure difference. The valve - both the inlet valve and the outlet valve - is designed as a lubricant-free spring valve, in further detail preferably as a tongue valve with a seal made of an elastomer.

It is further preferred that the valves in an easily replaceable or. also implementable valve bar are formed. This also means that simply turning the outer edge arrangement from inlet valve to outlet valve or. can be exchanged in reverse. This is important for the possible interconnection of several pumps in series or in parallel. Depending on the situation, the required valve can then be arranged (by turning the valve bar) in such a way that no long gas flow ducts are required. The valve bar is therefore a mirror image of a longitudinal axis educated. Inlet valves and outlet valves are located opposite one another in relation to a central longitudinal axis of the valve bar.

The valve tongues of the tongue valves are symmetrical. Spring steel is a suitable material, but also Viton, for example. Due to the fact that the valves are flat, a very minimized dead space associated with a reversed position of a piston can be realized. The inlet valves are flush with the surface of the valve rail. With regard to the outlet valves, a thin wall thickness is realized in the valve strip and / or, on the pump piston, a molded part can additionally be formed to avoid the dead space in front of the valve element.

The pump piston can have an opening projection associated with the outlet valve, for the purpose of triggering the outlet valve. In the case of an arrangement of several exhaust valves in a row, a corresponding number of opening projections is provided on the pump piston section. These raised surface elements on the pump piston cooperate with the outlet valves, in particular with the spring valves, in the reverse position and accordingly lead to a mechanical opening of an outlet valve.

It can also be provided that a pump has three, four or more pump pistons, two of which in any case move on a common circular path. If different circular paths are provided, on which two pump pistons each move, these different circular paths are preferably implemented in different pump housings. Each pump housing can have two oscillatingly movable pump pistons, the pump spaces of which are decoupled from one another in the respective pump housing by the housing partition walls , A common drive is preferably provided for the four pump pistons then given in the example mentioned above, the drive being arranged in one of the then two pump housings, preferably a separate third housing, a drive housing. It is more preferably then a drive housing, to which the two pump housings are assigned adjacent on both sides.

The housing - both the drive housing and the pump housing - can be designed as extruded parts. But they can also be castings, for example. A (first) assignment and fixing of the housings to one another can be achieved by joining them together by means of corresponding longitudinal grooves and longitudinal projections (in the direction of the axes of rotation of the pump pistons), which can be provided in a simple manner in the case of extruded parts. However, these longitudinal grooves and associated projections are generally only to be regarded as assembly aids. In addition, a screw connection and / or gluing or other connection between the housings is indicated.

In particular if the housing is designed as an extruded profile, a transfer channel can be easily integrated into the housing. It can namely be included in the housing as a cavity which extends in the direction of the axes of rotation of the pump pistons and is subsequently closed on one or both sides by appropriate covers.

To seal the pump chamber, the pump piston and / or the pump housing can be flocked in the area of an assigned movement gap. This flocking forms a running-in layer, which grinds off in the first working cycles to create a minimum gap. The flakes create an advantageous labyrinth effect. In this respect, of course, others can also alternative declarations (which also do not have the advantage of a labyrinth seal) can be applied alternatively.

A shrunk-in steel shaft can be provided in the pump piston, which is made of aluminum, for example, to form the physical axis of rotation.

The geometry of the pump chamber is preferably square, which means that the free path of the pump pistons between the reversed positions corresponds approximately to the extension of the pump chamber in the direction of the axis of rotation. The goal is to minimize the gap lengths. According to the formula, this prefers that the sum of twice the gap length and twice the difference between the outer and inner radius of the pump chamber is minimized. Pump chamber geometries can also be implemented in which the free path of the pump piston between the reversal positions is less than the extension of the pump chamber in the direction of the axis of rotation, and in which the free path of the pump piston is larger than the extension of the pump chamber in the direction the axis of rotation.

The invention is further explained below with the aid of a drawing which shows only a few exemplary embodiments or variant embodiments. Here shows:

1 shows a schematic plan view of the pumps in a first embodiment;

Fig. 2 is a schematic perspective view of two interconnected pump pistons 3 shows a schematic view of two pumps driven at the same time by means of a drive;

3a shows a schematic representation of a crankshaft flanged to the drive,

Figures 4 to 6 details regarding the sealing and valve actuation of the pump piston against the housing.

7 shows an embodiment of the housing partition with outlet valves;

8 shows a partial illustration relating to an alternative embodiment;

9 is a perspective view of a housing partition with inlet and outlet valves arranged therein;

FIG. 10 shows an explosion perspective view of the housing partition according to FIG. 9;

11 shows a longitudinal section through a pump housing with a view of a further alternative embodiment of housing partitions having outlet valves;

12 shows a perspective detailed illustration of the area of a pump chamber with outlet valves arranged in a housing partition; Fig. 13 is a representation corresponding to FIG. 12, but an alternative

Embodiment relating to, in which the rotary piston has opening projections associated with the exhaust valves;

FIG. 14 shows a detailed illustration according to the illustration in FIG. 4, but an alternative embodiment with regard to the gap sealing;

Kg. 15 a representation corresponding to FIG. 5, but relating to the sealing design according to FIG. 14;

16 shows the pump in a cross section;

FIG. 17 shows the pump according to FIG. 16 in a rear view;

18 shows a perspective view of a drive housing with separate pump housings arranged on both sides;

19 to 21 partial view of a valve bar with further embodiments of the inlet / outlet valves;

22 to 24 are sectional views relating to FIGS. 19 to 21;

FIG. 25 shows a representation according to FIG. 17, but with a separate design

Pump housings within an overall housing;

Fig. 26 is a further view of the object of FIG. 25, with the

Crank drive attacking pump housings. Shown and described first with reference to FIG. 1 is a pump 1 with two pump pistons 2, 3, which are connected to one another via a common entrance area 4, which in the exemplary embodiment has a circular cross section. In the central area 4 there is also the 5 axis of rotation 5, about which the pump pistons 2, 3 oscillate back and forth.

Pump pistons 2, 3 are operated clockwise from the position shown in FIG. 1 (1st reversal position) until the second reversal position is reached.

10 lung moves, where they each overflow the inlet valve 9. Then a pressure builds up between the pump piston and the housing webs 6, 7 until the preset counterpressure of the outlet valve 8 is reached (or, as described further below, it is forced to open). The pump pistons are then in a reverse position. Based on this

15 she actively moves back, opposite to her first movement, and the process is repeated in this reverse direction of rotation.

The pump pistons covering an angular range α of approximately 60 ° in the exemplary embodiment each move accordingly over an angular range of

20 120 °. In the area of 180 °, two housing partition walls 6, 7 are formed opposite one another in the pump housing 18 (only shown schematically). In the exemplary embodiment according to FIG. 1, an outlet valve 8 is formed in the direction of rotation of a pump piston 2, 3 in front of the housing partition 6 or 7, for example, in the 90 ° range of the 180 ° pumping space in which a pump piston 2 or 3 is located.

25 moves, an inlet valve 9 is formed.

In an alternative embodiment in this respect, the pump pistons are designed over an angular range of approximately 90 °, so that they also each move over an angular range of 90 °. Sealing advantages result from the larger sealing lengths. Another advantage is that the inlet valve is not open for too long and the gas is not partially pushed out again (on the way back).

In addition, angular extensions of more than 90 ° with respect to the piston are also possible. For example 110 °, 120 ° or 130 ° or intermediate degrees. You can then do without the compression on the back. The inlet valve is then suitably arranged close to the pump piston at the start of compression.

While the outlet valves 8 are non-return valves, an inlet valve 9 is designed as a simple opening.

In Figure 2, a double piston is shown alone in perspective. A height h of a piston 2 or 3 can correspond to a radius r from the axis of rotation 5 to a piston outer wall 10. Furthermore, a diameter D of the central region 4 preferably corresponds to approximately one third of the total diameter d of the two pump pistons 2 and 3 formed as a unit together with the central region 4.

FIG. 3 schematically shows a drive of two pumps 1 driven together by means of an electric motor 11. A crankshaft 12, schematically indicated in FIG. 3a, is flanged to the electric motor 11, by means of which the pump pistons 2, 3 are driven in opposite directions via connecting rods 13. The crankshaft 12 can have a counterweight or a flywheel 14.

The arrangement shown is also advantageous in that an arrangement in a space-saving manner while maintaining a horizontal position of the shafts It is possible in such a way that the entire unit can stand on only one pump as a standing surface, so that the motor and the further pump then extend in a tower-like manner, as mentioned, with horizontal waves. This can advantageously be implemented in that the housing is at once rectangular in the sense that it offers at least two installation surfaces. Firstly, one installation surface that corresponds to the arrangement in FIG. 3 and another installation surface for an arrangement as described above.

Figures 4 to 6 show details of the gap seals required for a high performance pump.

FIG. 4 schematically shows the gap seal radially on the outside on the pump piston 3. As an alternative to the seal already mentioned in the introduction to the description, the gap piston 3 can have such sealing lips 15 as a result of the gap dimension, which are firmly connected to the pump piston 3 and against an inner wall 16 of the pump housing. It can be, for example, plastic lips, for example made of PVC, PP or PE.

The same is also possible radially on the inside. Also with regard to sealing the housing partition / connecting wall of the pump pistons. In this respect, FIG. 5 schematically shows a seal between the housing web 7 and the central area 4. In this case, a sealing lip 17 is firmly connected to the housing web 6 and acts with the inner wall of the central area 4, which is designed to be non-rotatable with the pump pistons 2, 3 Pump housing sealing together.

FIG. 7 shows a cross section of the housing bridge 6 in an alternative embodiment. One, two or more outlet valves 8 are formed in each of the two housing webs 6, 7. The outlet valves 8 exist from valve disks 19, 20 which in the exemplary embodiment are connected to one another in a U-shaped cross section and bear against the bores 21, 22 under spring preload. Between the bores 21, 22 and the valve plates 19, 20, a seal 23, 24 is arranged, each of which has corresponding openings corresponding to the bores 21, 22.

As an alternative to opening the exhaust valves due to the excess pressure generated, a forced opening of the exhaust valves can also be provided, in particular when the exhaust valves are arranged in the housing webs as shown in FIG. 7, as illustrated in FIG. 6. Through an opening part firmly connected to each pump piston, which then pushes the valve plate into the open position. This is particularly advantageous with regard to the control times to be achieved.

In this context, but also independently of this, it can also be provided that the associated side walls of the pump pistons 2, 3 just touch the respective walls of a housing web 6, 7 in the reversed position. It is also advantageous here to have a soft, flexible coating, such as, for example, on the housing web and / or the associated wall of a pump piston 2, 3. realized by a rubber part, to be provided.

FIG. 8 schematically shows an alternative arrangement of outlet valves 8 and inlet valves 9. These are both arranged here in the area of a housing partition 6 separating the two pumping chambers 25 from one another. The diametrically opposed housing partition 7 is designed in the same way as the housing partition 6 shown.

As can be seen in particular in the detailed illustration in FIG. 9, the housing partition 6 is initially designed as a hollow part with a parallel to the Axis of rotation 5 of the pump piston 2 and 3 extending orientation. The cavity formed is interrupted approximately in the middle by a transverse wall 26. The outlet valves 8 and the inlet valves 9 are formed on both sides of this transverse wall 26, for which purpose the walls of the housing partition 6 facing the pumping chambers 25 are first provided with bores 21, 22.

Each with a hole 21 or. 22 side of the housing partition 6 is assigned an inlet valve 9 and an outlet valve 8, which, regardless of the function of the valve, initially has a closure actuator 27 to which a bending section 28 is connected. The locking plate 27 and the bending section 28 are in one piece formed, these merge into one another at the same level and are formed from a stamped or bent sheet metal part, in particular from a spring steel part. The bending sections 28 extend approximately in Langser's stretching of the housing partition 6, that is to say parallel to the axis of rotation 5.

On the end side, that is to say facing away from the locking plate 27, the bending section 28 forms a mounting foot 29. The spring part of the inlet valve 9 formed by the locking plate 27, the bending-out section 28 and the mounting foot 29 is shaped like a key with respect to a plan view of the same. But it can also be shaped as a continuous, straight tongue.

The spring part 30 of the outlet valve 8 has two support feet 29 arranged opposite one another at the end of the bending section 28, whereby the latter and the bending section 28 are arranged in a T-shape with respect to one another.

A membrane-like support 31 is provided between the spring part 30 and the associated wall of the housing partition 6, which inlet valve 9 is adapted in terms of floor plan to the floor plan of the associated spring part 30, cf. 10, in particular, here too, a stem-like section 32 is provided, at one end of which a mounting foot 33 is arranged approximately at right angles thereto, and the other end of which carries - in the specific exemplary embodiment: circular - sealing section 34 with an outer diameter that fits on the outer diameter of the locking plate 27 and with an inner diameter which is adapted to the diameter of the associated bore 22 in the housing partition 6

The support 31 of the outlet valve 8 is elongated in rectangular plan with an integrated sealing section 34 assigned to the locking plate 27 of the spring part 30, the passage opening of which also corresponds to the diameter of the assigned bore 21 in the housing partition 7.

Two inlet valves 9 and outlet valves 8 are provided for each housing partition wall 6 and 7, each directed towards the pumping chamber 25 which is sealed off from one another by the housing partition walls 6, 7. Accordingly, the valves lie in pairs opposite one another.

The outlet valves 8 or the spring parts 30 and supports 31 forming the outlet valves 8 are arranged on the inside of the housing of the housing partition 6, a support 31 being clamped between the spring part 30 and the associated housing part. For this purpose, a pressure part 35 is provided. This is positioned in the area of the spaced-apart mounting feet 29 of the two spring parts 30 in the hollow-chamber-like housing partition. As a result, a foot-side bearing is formed for the outlet valves 8 designed as spring valves. As an alternative to the clamping bracket, but possibly also as a supplement, an adhesive bond can also be provided. The supports 31 and spring parts 30 of the inlet valves 9 are in contour-adapted recesses 36 of the outer walls of the housing partition wall 6 and 7 facing the pumping chambers 25, the supports 31 being clamped between the spring part 30 and the associated housing wall by means of a clamping part 37. This clamping part 37 engages over the housing partition 6 or 7 in the region of a recess on the ceiling. In the clamped position, the two legs of the clamping part 37 with a C-shaped cross-section overlap the mounting feet 33 and 29 of the supports 31 and spring parts 30, as a result of which the tongue valves are also supported at the ends.

The arrangement of the outlet valves such as the inlet valves in the housing partition provides an advantageously small dead space and thus better compression.

The valve control is preferably pressure-dependent. Starting from a reversed position, a vacuum is generated by the pump piston 2 or 3 migrating from the housing partition 6 or 7, which causes the inlet valves 9 to open if a preselected threshold value is exceeded. When the pump piston 2 or 3 compresses the medium in the direction of the housing partition 6 or 7, a pressure increase is achieved which causes the outlet valves 8 to open.

The spring parts 30 of the outlet valves 8 are prestressed in the direction of the assigned pumping chambers 25, accordingly open when the pressure is exceeded inwards in the direction of the hollow chamber of the housing partition 6 or 7. The spring parts 30 of the inlet valves 9, however, are in the direction of the assigned hollow chamber in the housing partition 6 or 7 biased and open by bending in the direction of the pump chambers 25 when a predetermined vacuum value is exceeded.

As can further be seen from the sectional illustration in FIG. 11, a plurality of outlet valves 8 provided in a side-by-side arrangement can also be provided in the housing partition walls 6 and 7. For example, three outlet valves 8 are provided here for each housing partition 6 and 7. These exhaust valves 8 are designed similarly to the previously described exhaust valves 8, and accordingly have tongue-type spring parts 30. These spring parts 30 of all three outlet valves 8 of a housing partition 6 or 7 are formed in one piece, the respective mounting feet 29 opening into a common base 38.

In this exemplary embodiment, the respective inlet valves 9 of each pump chamber 25 are designed as a permanent opening 39, thus in the form of a bore in the bottom region of the pump chamber 25 (cf. FIG. 12). The inlet valve 9 designed in this way overflows when moving from one reversing position to the other reversing position.

Furthermore, the illustration in FIG. 13 shows an alternative embodiment, in which the pump piston 2 or 3, assigned to the outlet valves 8 arranged side by side in the housing partition 6, 7, each has an opening projection 40 for triggering the outlet valves 8 by acting in the one reversed position. The closure plates 37 of the outlet valves 8 are mechanically pushed into their valve opening position via these opening projections 40

14 and 15 show further details of the gap seal between the pump pistons 2, 3 and the pump housing. Pump piston 2 or 3 is like this Provided on the outside radially in the area of the movement gap with a flocking 41, which serves as a finishing layer, which grinds off in the first working cycles to produce a minimum gap. The same is also possible radially on the inside. 15 schematically shows a seal with a flocking 41 between the housing web 7 and the central region 4. In addition, such flocking is also provided on the end side of the pump piston 2, 3, which is not shown in detail. The flocking is only a preferred coating to achieve the desired tightness. Other coatings are also possible.

16 shows a cross section through the pump housing G. This is made as an extruded part, for example made of aluminum, and has a central section for receiving the electric motor 11. Pump chambers, each with two pump pistons 2, 3, are provided on both sides of the electric motor 11, each moving on a common circular path. Each pump piston 2, 3 is assigned to a pump chamber 25, which are separated from one another by diametrically opposed housing partition walls 6, 7, in which outlet valves 8 are also arranged. The inlet valves 9 are formed on the front side of the pump chambers 25.

17 shows a rear view against the pump 1. It can be seen that the two pairs of pump pistons arranged on the side are driven by a crank mechanism via the centrally arranged electric motor 11. For this purpose, arms 43 rotatably mounted on the electric motor 11 or on its output shaft 42 are provided, via which a connecting rod length 13 can be driven in each case, for driving the pump piston pairs in opposite directions. Alternatively, what is not shown in detail, a stepper motor drive of each pump piston pair is also possible here. Another alternative is an electro-mechanical swing arm.

Finally, the perspective in FIG. 18 shows a further embodiment of the pump housing G, which is constructed in three parts. Thus, a drive housing 44 and two pump housings 18 each designed to receive a pair of pump pistons are provided. These housings are formed from extruded parts, so preferably from aluminum.

The drive housing 44 is designed to receive the electric motor 11 accordingly

The two pump housings 18 are designed to be interchangeably identical and can be arranged symmetrically to the drive housing 44. Accordingly, the two pump housings 18 can be formed from one and the same extruded profile.

The two pump housings are fixed to the drive housing 44 by means of extruded longitudinal grooves 45 and corresponding, cross-section-adapted projections 46. In addition, pinning, screwing or gluing (alternatively or also in combination) is preferably provided.

The selected design, in particular of the pump housing 18, makes it possible to achieve different lengths of the pumping chambers 25 in a very simple manner, with reference to an axis of rotation of the pumping pistons, which further allows the geometry of the pumping chambers 25 to be preset in the simplest form so as to be adaptable to different needs. In this case, the most square possible pump Chamber geometry preferred, in which the diameter of the pump piston corresponds approximately to the extent of the pump chamber 25 in the direction of the axis of rotation 5.

Accessories, such as suction or discharge ports, can also be provided at the front and rear, when viewed in the direction of the axes of rotation. In this case, such accessories can also be integrated in terms of shape, for example in the sense that they fit into the gaps between the motor housing and the drive housing which result in the embodiment shown.

The pumps can also have separate housings with which they are then inserted into the overall housing shown.

Regarding the choice of material, it is provided that the pump piston and the pump housing consist of the same material. If different materials are provided, it is provided that the pump piston consists of a material with a lower expansion coefficient compared to the material of the pump housing.

With reference to Figures 19 to 24, further embodiments of the intake / exhaust valves are shown.

In the embodiment of FIG. 19, an outlet valve is formed which only consists of a valve tab 47 which is arranged on the inside of a housing web 6 and which - in this case special - opening in the housing web 6 or 7. It is essential that a multiplicity of individual openings 48 are formed in the region of the outlet, so that webs remain between them, which serve as a support for the valve tab 47. This can be very soft be formed without it squeezing into the outlet opening more than justifiable due to negative pressure.

Basically, the same design is also possible for an inlet valve. It may be advisable to form a recess in the outer wall, in which the valve flap lies, in order to maintain a smooth transition in the outer wall between the valve flap and the outer surface.

The cross-sectional representation corresponding to FIG. 19 is shown in FIG. 22. It can be seen here that one valve tab 47 is in the outlet position, while the other valve tab 47 lies sealingly against the inner wall

In the embodiment of FIG. 20, a ball valve is implemented. In this respect, it is essential, also with regard to the embodiment of FIG. 21, that the outlet and inlet valve is designed as a combined valve. The inlet position of the inlet valve is immediately coupled to the sealing position of the outlet valve and vice versa. A (numerical word) active body, here the closure ball 53, is both the inlet valve active body and the outlet valve active body.

Specifically, in the embodiment of FIG. 20, a cage 49 is provided which has openings 50 with respect to a gas supply line and gas discharge line (not shown in detail). The cage 49 has, in association with the housing web 6 or 7, a circumferential sealing flange 51, 52. This can also be suitably covered with a sealing material such as a rubber or elastomer on the inside, on the ball side. The cage 49 can also be made integrally from such a material. A locking ball 53 is caught in the cage 49. Depending on the pressurization, this moves into its corresponding one Sealing position. The cage extends between the housing webs 6, 7, connecting them transversely.

Obviously, only a very small pressure difference is required for activation or displacement in the valves described here. They work without or practically without a preload. This is also due to the fact that the pumps or compressors described here are preferably operated with a low pressure difference. In any case, when a volume flow is of primary importance. The pressure difference can be in the range of one or less tenths of a bar.

With reference to FIGS. 21 and 24, in accordance with the embodiment in FIG. 22, a valve is again shown which also functions as an outlet and inlet valve. Specifically, it consists of two valve disks 54, 55, which are preferably rigidly coupled to one another via a connection 56, rod-shaped in the exemplary embodiment. The connection 56 in turn extends transversely to the housing webs 6, 7. In the interior of the valve strip or in any case between the housing webs 6 and 7, the connection 6 is suspended by means of a spring part 56. As a result, it can be aligned with a central position, which corresponds to an opening of both the inlet and the outlet valve. This can also pull it into a closed position of the inlet or outlet valve.

Alternatively or in addition, only a tube-like guide can also be provided. This is particularly the case if, in deviation from the specific embodiment shown, one of the valve disks 54 or 55 comes into contact with the inside of a housing wall 6 or 7 in the sealing position.

FIGS. 25 and 26 show a pump in which the pump pistons are not only in a separate housing, referred to here as the first housing 57 run, which in turn is then still accommodated in the outer housing 58, but in which the housing 57 is also rotatably accommodated in the housing 58 and, by means of the crank mechanism shown in FIG. 26, preferably by the same drive that drives the pump pistons, is moved in opposite directions during a pump piston movement. The absolute movement of a pump piston from one to the other reversed position can be halved, for example (with the same delivery rate).

In this embodiment, the housing 58 can also be made in several parts in the same way as is described with reference to FIG. 18.

All of the features disclosed are (in themselves) essential to the invention. The disclosure content of the associated / attached priority documents (copy of the prior application) is hereby also included in full in the disclosure of the application, also for the purpose of including features of these documents in claims of the present application.

Claims

EXPECTATIONS

1. Pump (1), such as a vacuum pump or compressor, with at least one pump piston (2, 3) moving on a circular path and a pump housing (18), the pump piston (2, 3), possibly rigidly coupled to an or several further pump pistons (2, 3), oscillating about an axis of rotation (5) on a movement path that has two reversing positions, whereby a compressed or pressurized medium is discharged via an outlet valve (8) and in the course of a Movement from one reversing position to the other reversing position, an inlet valve (9) is opened, after which, on a pressure side of the pump piston (2, 3) which is then given in each case, a discharge in the course of a pressure build-up and an intake on a suction side of the pump piston (2, 3) of the medium.

2. Pump according to claim 1 or in particular according thereto, characterized in that the inlet valve (9) is overflowed during the movement from one reversing position into the other reversing position.

3. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the pump space is formed radially on the inside by an inner wall which is designed to rotate with the pump piston.

4. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the outer wall of the housing, which delimits the pump space radially on the outside, is fixed.

5. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the outer wall of the housing delimiting the pump space radially is movable

6. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the inlet valve (9) is formed in the pump chamber floor and / or in the pump chamber ceiling and / or in the outer housing wall and / or the housing partition wall.

7. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the pump chamber in the direction of movement of the pump piston (2, 3) is limited by a fixed housing partition

8. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the outlet valve (8) is designed as a check valve.

9. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the outlet valve (8) is formed in the housing partition, and / or in the pump chamber floor and / or in the pump chamber ceiling and / or in the housing outer wall

10. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the pump is driven by an electric motor.

11. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the pump is driven by a stepper motor

12. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the pump is driven by an electromagnetic oscillating part.

13. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the drive takes place by means of a crankshaft.

14. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the drive acts on two or more pumps connected via the same crankshaft.

15. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that in the case of two pumps (1) driven by the same crankshaft, they move in opposite directions.

16. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the inlet valve (9) and the outlet valve (8) are arranged assigned to the same end region of the movement path.

17. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the inlet valve (9) and the outlet valve (8) are arranged in the same housing partition (6, 7).

18. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the inlet valve (9) and / or the outlet valve (8) is formed from a stamped or bent sheet metal part, with a vent opening (21, 22 ) associated locking plate (27) and an adjoining bend section (28).

19. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the closure plate with the same diameter merges into the bending section (28)

20. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the inlet valve (9) and / or the outlet valve (8) has closure plates (27) and bending sections (28) which merge into one another at the same level.

21. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that an inlet valve (9) and / or an outlet valve (8) has a mounting foot (29) which is clamped.

22. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the Halterungsfαß (29) at the same level in the Ausiegeabsclmitt (28)

23. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the closure plate (27) rests on a support (31) which is clamped between the valve and the associated housing part.

24. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the clamping bracket is achieved by means of a clamping part (37).

5

25. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the clamping bracket is achieved by means of a pressure part (35)

10. 26. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the longitudinal extent of the inlet valve (9) and / or the outlet valve (8) runs parallel to the axis of rotation (5) of the pump pistons (2, 3)

15 27. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that a plurality of outlet valves (8) are arranged side by side parallel to the axis of rotation (5).

28. Pump according to one or more of the preceding claims or 20 in particular according thereto, characterized in that the pump piston (2, 3) associated with the outlet valve (8) has an opening projection (40) for triggering the outlet valve (8).

29. Pump according to one or more of the preceding claims or 25 in particular according thereto, characterized in that the opening projection, projecting towards a corresponding end face of the pump piston (2, 3), is formed as a tappet

30. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that a pump (1) has four - or a higher multiple of two - pump pistons (2, 3), two or more of which are on a common one Orbit moving.

31. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that in each case two pump pistons (2, 3) moving on a common circular path are arranged in a separate pump housing (18).

32. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that a common drive for the four pump pistons (2, 3) is provided and that the drive is arranged in a drive housing (44) separate from the pump housing (18) is

33. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the drive housing (44) is arranged between the pump housings (18)

34. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that in the case of a plurality of pump housings (18), the pump housings (18) are designed to be interchangeably identical to one another.

35. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the pump piston (2, 3) and / or the pump housing (18) is coated in the area of an assigned movement gap.

36. Pump according to one or more of the preceding claims or in particular according thereto, characterized in that the coating is a flocking.