DE602004003814T2 - ROTARY PISTON OR ENGINE WITH A SINGLE WING - Google Patents

Abstract

A rotary vane pump or motor comprising a housing ( 16 ) with cylindrical inner peripheral wall defining a cavity, and a rotor ( 20 ) with cylindrical peripheral surface and a socket ( 41 ) internal to said peripheral surface, eccentrically disposed in the cavity. The rotor ( 20 ) is adapted to scroll the inner peripheral wall in close proximity thereto. The inner peripheral wall and the rotor surface define a working chamber between them. The housing ( 16 ) has a vane ( 22 ) with an end received within the socket ( 41 ) so as to enable the vane to slide in the socket maintaining predetermined degree of fluid tightness therebetween, and to enable the rotor ( 20 ) to orbit the cavity. The housing ( 16 ) has an inlet port ( 24 ) adjacent one side of the vane and an outlet port ( 26 ) adjacent the other side of the vane, both ports being open to the inner peripheral wall.

Description

AREA OF INVENTION

The The present invention relates generally to vane pumps and motors and special rotary lobe pumps with a single wing, designed for pumping of liquids used in the chemical, medical and food industries Be where the needed Process purity frequent Pump cleaning or replacement required.

BACKGROUND THE INVENTION

The rotary lobe pump / single-rotor rotary lobe engine is known in history from attempts to construct a steam engine with a rotary lobe. Later, the scheme was applied to compressors / pumps. (It is known in the art that in general, a rotary engine (engine) can be converted to a pump when an external drive is available, and vice versa.) Thus disclosed GB 926,495 a rotary lobe pump in which the general structure comprises a housing having a cylindrical cavity and a cylindrical piston (rotor) of lesser diameter, which is arranged eccentrically therein. The pump drive by means of an eccentric crank causes the piston to rotate in the cavity by rolling its inner peripheral wall. A sickle-shaped pump chamber is thus defined between the piston and the housing. The piston has a radial projection (wing) received in a recess of the housing, which divides the chamber into an expanding chamber and into a contracting chamber. Further, the pump has an inlet opening on one side of the wing, which is connected to the expanding chamber, and an outlet opening on the other side of the wing, which is connected to the contracting chamber. In one embodiment, the vane has a cylindrical tip, while the recess is a radial channel having parallel walls that contact the cylindrical tip and allow the vane to slide and pivot. In another embodiment, the wing and the recess have a triangular shape.

Some Examples of single-lobe rotary lobe pumps are in the Japanese publication JP 06-200887. The pump has a single wing that over the Pump chamber is connected to the rotor and the housing. At a embodiment is the wing slidably connected to the housing, while it is rotatably mounted on the rotor. In a second embodiment is the wing also slidably connected to the housing - but the wing is not connected to the rotor, but by a spring in the sliding joint pushed radially to the rotor, so that the wing slidably in contact with the rotor. In a third embodiment is the wing integrated into the rotor while he slides through a pedestal, which in turn rotatable with the Housing connected is.

at most embodiments is the outlet opening closed by a one-way valve to return fluid or to prevent pressure loss when the rolling zone of the rotor over the wing joint happened because neither the wing nor the rotor in this position, the inlet opening of the outlet opening of Isolate the pump.

FR 656 320 and DE 2 262 574 disclose a single-vane rotary pump according to the preamble of claim 1, wherein the single vane is surrounded by lips formed on the rotor.

SUMMARY THE INVENTION

According to the present invention, there is provided a rotary pump or motor comprising a housing having a cylindrical inner peripheral wall defining a cavity and a rotor having a cylindrical peripheral surface and a socket inwardly of the peripheral surface eccentrically disposed in the cavity , The rotor is adapted to roll off the inner peripheral wall in close proximity thereto. The inner peripheral wall and the rotor peripheral surface define a working chamber between them. The housing has a wing with one end received in the socket, such that the wing is able to slide within the socket and to provide a predetermined liquid tightness therebetween and to allow the rotor to move within the socket Circling, wherein the wing has a uniform thickness and is rigidly secured to the housing, and wherein the base has an opening with rotary jaws and is received between the jaws to form a hinge, which is the sliding of the wing through the joint and allowing the wing to swing back and forth with the joint while maintaining liquid tightness. The housing has an inlet port adjacent one side of the blade and an outlet port adjacent the other side of the blade, both ports being in fluid communication with the cavity via the inner peripheral wall. The rolling zone in close proximity between the rotor surface and the inner peripheral wall of the housing and the blades divide the working chamber into a first expanding inlet chamber in fluid communication with the inlet port and a second concentrating outlet chamber into fluid connection with the outlet opening.

at In one example, the pedestal has parallel walls and the wing has a cylindrical tip received in the socket, and so liquid tightness with the walls ensures. The wing is rigid on the housing attached, but he is thinner as its cylindrical tip, causing a swinging back and forth within the socket allows.

at In another example, the base has an opening with two rounded ones Lips holding the wing take in between and thus the preservation of the liquid-tightness provide. The socket has a wider cavity behind the Lips, so that the wing is able to swing back and forth within the socket. The wing can have parallel walls which, with variable reciprocating angles and variable liquid tightness provides. Alternatively, the projections be elastic, or the wing thickness can over the Wing length vary, with variable reciprocating angles approximately uniform liquid tightness provided.

According to the invention the socket an opening in the form of a cylindrical rotating jaw, which is the sliding of the wing of uniform thickness through the joint and swinging back and forth of the grand piano together with the joint allows.

at In other examples, the pedestal has parallel walls and the end of the wing, which in the socket is accommodated, fits to the recess between the parallel walls, but the wing is not rigid on the housing attached. The wing can by a hinge on the housing be fixed or it can be made flexible to yourself bend, when the rotor is in the housing circles. Preferably in the latter case connect the parallel Walls the peripheral surface along a slight curve, which allows the wing to curve easily.

The inventive design offers two major advantages. The first advantage is the ability to position the inlet and outlet of the pump / motor in closer proximity to one another, and thus reduce the angle of rotation at which the rotor and cylinder are not in rolling contact. The second advantage is that the rotor is in equilibrium when it is exposed to fluid pressure, since the seal between the blade and the rotor takes place on the rotor circumference. Thus, the fluid pressure imparts a force directed through the rotor center resulting in negligible force between the blade and the rotor base, unlike prior art rotors where the projecting blade is subjected to pressure exerting the blade against its pedestal urges, causing friction. (Note: this advantage applies to the in 6 not shown). An additional advantage of the wing, which extends inwardly from the housing, is the structural compactness that is obtained with pumps employing long wings.

According to one additional Embodiment of present invention, the rotary pump or motor comprises a Seal barrier, arranged between the rotor circumference and the inner Peripheral wall, preferably adjacent to the inlet opening or to the outlet opening. The lock is adjusted to fluid connection between the inlet opening and the outlet opening to prevent if the roll over the inlet or the outlet opening or in between. Preferably, a second seal barrier adjacent to the other opening arranged. The seal barrier can be made of resilient material be and attached to the inner peripheral wall or on the rotor circumference be. Alternatively, it can act as cooperating teeth on the inner peripheral wall and on the rotor peripheral surface be formed. The seal barrier can act as an integrated element in the lips at the base opening be formed. This is a pump or motor with a single wing provided, which are not one-way valves for operability requires, but rather uses a barrier to a separation between to obtain the pump or motor inlet and outlet.

According to one another embodiment In the present invention, the rotary lobe pump is used in a pumping device. that to a drive unit with an eccentric drive element coupled, which is adapted to drive the rotor. The Pump can be attached to and detached from the drive unit wherein the two units are constructed such that the fastening the pump on the drive unit in the connection of the rotor with the eccentric drive element results. Preferably included the pumping device Fasteners, which provide easy operation without tools enable.

Preferably, the rotor has a concentric socket, the eccentric drive element comprises an eccentric crank adapted to rotatably fit within the concentric socket by means of a bearing when the pump is attached to the drive element, and the housing has a sealed opening which it allows the crank to penetrate into the concentric socket. Preferably, the crank has a conical head with such a diameter and eccentricity that it can penetrate into the concentric socket, regardless of the orientation between the pedestal and the crank before fixing.

The Rotary pump is preferably made of materials that for your Use as a disposable unit are suitable, such as plastic.

Consequently becomes a pumping device, which is constructed of two major components provided: One permanent drive unit containing all costly components, and a cost-effective disposable pump unit, which comes in contact with the pumped funds and the fast and is easily replaceable. The disposable pump unit contains all pump parts, which is exposed to a high degree of wear or contamination are such that their replacement results in a complete pumping device, which as good as new in terms of wear and cleanliness.

Further For example, the rotary lobe pump of the present invention may include a bypass passage which preferably in the housing is integrated, with an inlet in communication with the inlet opening, an outlet in communication with the outlet opening, and a one-way valve, which is arranged between the inlet and the outlet to one liquid flow to allow bypassing the pump chamber, while the flow constant to improve while the rotary lobe pump pulsates during the pumping process. Furthermore, can the pump has a pulsation damper comprising an air chamber connected to the outlet, adapted for damping the pressure waves that are present at the outlet of the rotary lobe pump.

Other Objects and features of the present invention will be considered in view of the detailed description of the preferred embodiment in conjunction with the attached drawings and the claims in the appendix obviously.

SHORT DESCRIPTION THE DRAWINGS

To the understanding The invention and its application are now preferred embodiments by giving only non-limiting examples, with reference to the accompanying drawings, in which:

1 a schematic cross-sectional view of a pump with a single wing, coupled with a pulsation damper and a bypass valve, only as an example;

2 a schematic sectional view of the pump with a single wing of 1 is, with the rotor in registry with the surroundings of the liquid inlet and outlet openings.

3 a sectional view of the pump with a single wing of 1 Fig. 11 is the attachment and coupling of the pump to the drive unit and the eccentric drive element;

4 a sectional view of the pump with a single wing of 3 Fig. 11, which shows the disassembly and disconnection of the pump from the drive unit and the eccentric drive element;

5 Fig. 4 is a sectional view of the single wing pump according to an embodiment of the present invention;

6 just an example;

7 Fig. 10 is an enlargement of an example in which the lips of the base and a sealing barrier are integrated in one element;

8th an example with a hinged wing is; and

9 an example with an elastic wing is.

DETAILED DESCRIPTION

With reference to 1 to 4 becomes a pumping device 10 just given as an example. The pump device 10 includes a pump with a single wing 12 and a drive unit 14 , which are detachably attached to each other.

The pump 12 includes a housing 16 with a cylindrical cavity and a cylindrical rotor 20 which is arranged eccentrically in the cavity of the housing to a working chamber 18 set. The housing 16 has an inlet opening 24 and an outlet opening 26 that with the working chamber 18 communicate, and a radial wing 22 that between openings 24 and 26 is arranged. openings 24 and 26 are on the inner peripheral wall 28 open the working chamber. The housing 16 includes a bypass channel 29 with an inlet 30 in connection with the inlet opening 24 , an outlet 32 in connection with the outlet opening 26 and a one-way valve 34 between the inlet and the outlet. Two sealing barriers 35 are on the perimeter wall 28 arranged, adjacent to the inlet opening 24 or the outlet opening 26 , The housing 16 points to its wall 37 a central opening 36 and a cover 38 on, the working chamber 18 closes.

The rotor 20 is in the housing cavity in sliding contact with the cover 38 and the wall 37 arranged, leaving the opening 36 by means of a ring seal 40 seals. The rotor 20 has a radial base 41 with two rounded lips 42 at its mouth opening the wing 22 connect it so that it is in the radial socket 41 can slide. The lips 42 stand with both sides of wings at all times 22 in contact, in sealing form. wing 22 has different thickness to contact with both lips 42 Nevertheless, it allows a free movement of the rotor 20 , wing 22 and the pedestal 41 thus provide a connection that provides both sliding and swinging. rotor 20 also has a central base 44 on, the opening 36 is facing. As in 6 shown, can wings 22 with an enlarged cylindrical tip 80 be made while the wing base 41 has parallel walls, which is a glide of lace 80 and a swing of rotor 20 enable. Alternatively, the lips can 42 be made of elastic material. As in 7 The lips can be shown in an element 82 be integrated with the seal lock. 8th and 9 show further possible embodiments of the invention - wings 84 with joint 86 and elastic wings 88 with rounded base entry 90 , Such wings can only slide in a narrow pedestal 91 be prepared without swinging back and forth, for better fluid tightness.

drive unit 14 has a wave ring 50 with an eccentric crank 52 equipped with a bearing 54 , Is the pump 12 on the drive unit 14 attached, the crank is 52 from the central pedestal 44 picked up and wave ring 50 is coaxial with the cylindrical cavity of the housing 16 ,

The radial geometric relationship of drive unit 14 , eccentric crank 52 , Rotor 20 and diameter of the cylindrical pumping chamber 18 is such that a rotation of the shaft ring 50 over the crank 52 the rotor 20 for unrolling the inner peripheral wall 28 brings, being in contact or almost contact with the wall in roll zone 56 is maintained. Due to the wing-and-socket connection of rotor 20 to the housing 16 where rotor 20 to the wing 22 by means of a wing pedestal 41 is delimited, the rotor simultaneously performs a reciprocating motion parallel to the wing base and a transverse oscillatory movement (a circular movement).

During this circular motion put rotor 20 and housing 16 two separate and distinct volumes: an expanding inlet chamber 58 and a contracting outlet chamber 60 , The expanding chamber 58 is between the inlet side of the wing 22 , a part of the peripheral wall 28 between the inlet opening 24 and the rolling zone 56 and an adjacent part of the rotor circumference. The contracting chamber 60 is between the outlet side of the wing 22 , the remaining part of the peripheral wall 28 between the outlet opening 26 and the rolling zone 56 and the remaining part of the rotor circumference.

Rotates the eccentric crank 52 counterclockwise (see 1 ), directs the roll zone 56 also to the left and the expanding chamber 58 expands, taking liquid out of the inlet 30 is drawn or sucked through the inlet opening 24 , At the same time, the contracting chamber contracts 60 together, with the liquid through the outlet opening 26 to the outlet 32 is drained. At the in 2 shown position is the roll zone 56 with wings 22 in overlap, leaving the contracting chamber 60 disappeared while the expanding chamber 58 has reached its maximum volume, after which it begins to contract and become the contracting chamber, while at the same time creating a "new" expanding chamber.

In the position of 2 is the rotor 20 in contact with the sealing barriers 35 , where he has a possible connection between the inlet opening 24 and outlet opening 26 around the rotor 20 seals. The locks 35 are made of elastic material, such as rubber, so that they are from the rotor 20 be bent when he rolls on them. In the absence of the locks 35 when the rotor 20 is in the position shown, or rather in any position where roll zone 56 in overlap with either inlet opening 24 or outlet opening 26 or between them, could be pressurized fluid from the outlet port 26 around the rotor 20 back to the inlet opening 24 flow. This undesirable backflow is traditionally prevented by the use of a one-way valve at the outlet port. seal locks 35 perform a similar function by controlling the fluid return flow from the outlet port 26 to the inlet opening 24 prevent without the negative effects that valves bring.

In particular, liquid backflow may also be due to a single seal barrier 35 be prevented. In such a case, the single barrier should provide the seal of a slightly wider gap. For example, the left lock in 2 removed, the remaining right-hand lock must 35 the gap between the rotor 20 and the inner wall 28 Keep tight until the roll zone 56 a point to the left of the inlet opening 24 reached.

It would be obvious to professionals that every lock, suitable between the rotor 20 and the inner peripheral wall 28 arranged, the function of blocking the return flow path of the outlet opening 26 to inlet opening 24 can perform. For example, the barriers may be on the rotor circumference opposite the openings 24 and 26 be arranged as in 5 shown. Alternatively, a labyrinth barrier 43 , shown in an enlargement of 2 are formed as cooperating teeth on the inner peripheral wall and on the rotor peripheral surface.

The bypass one-way valve 34 is optional. It is made of elastic material, such as rubber, which can flex under pressure differential applied thereto, preventing liquid from entering 30 to outlet 32 flows. Thus, continuous fluid flow can also occur at the time when the expanding chamber 58 and the contracting chamber 60 no fluid displace, be maintained.

In the illustrated example of 1 will the pump with a single wing 10 with an additional mounted pulsation damper 64 shown in this embodiment, an air entrapment container with liquid outlet 66 is. damper 64 Absorbs and dampens pressure waves or fluctuations caused by the cyclic nature of fluid displacement in the single-vane pump 10 come. The air inclusion 68 expands and contracts in response to pressure fluctuations of the liquid at the outlet 32 , being, together with bypass valve 34 , a stable and uniform flow and pressure of the pumped liquid at outlet 66 is improved.

3 put pump 12 of the pumping device 10 attached to drive unit 14 , with the rotor 20 who is over camp 54 to the eccentric crank 52 is coupled. The pump is made by wing nuts 70 held in position manually on in drive unit 14 anchored threaded bolt 72 screwed and tightened. drive unit 14 has a lead 74 on, the way to the recess 76 in housing 16 fits that pump 12 in an appropriate ratio positive fit to drive unit 14 is.

4 put pump 12 from drive unit 14 dismantled with wing nuts 70 that of the threaded bolts 72 are removed. cover 38 can be an integrated part of pump 12 be that permanently attached to housing 16 is attached, or it can by housing 16 be separated. In the illustrated embodiment, it serves both as a cover for the housing 16 as well as a holding plate for attaching the pump 12 that with drive unit 14 connected is. It is believed that there are other simple and rapid means of manually attaching the pump to the drive unit, such as a bayonet or threaded collar.

The eccentric crank 52 has a conical head 78 on, introducing the crank 52 in the pedestal 44 of the rotor 20 facilitated. The diameter of the conical head 78 and the eccentricity of the crank 52 are chosen such that the conical head 78 in the crank socket 44 can penetrate while the pump is attached to the drive unit regardless of the orientation of the socket 44 and the crank 52 , For this purpose, the crank eccentricity is preferably less than a quarter of the diameter of the crank head (the latter being considered as corresponding to the base 44 diameter).

The inventive rotary piston pump can Easily disposable in the chemical, medical and food industries be adjusted where needed Process purity frequent Pump cleaning or replacement required. For this purpose, the Pump from inexpensive Materials manufactured for their use as a disposable unit, such as Plastic. The described structure of the wing-and-socket connection allows a simple pump production from molded components. Thus, the pump parts, which come in contact with the pumped funds, inexpensive and easily and quickly replaced by a simple operation, without to use any tools. The disposable pump unit preferably includes all pump parts requiring a high degree of wear and contamination are exposed while the permanent drive unit, including the eccentric crank with the bearing, containing all the expensive components. Consequently results in the replacement of the disposable pump unit in a complete Pumping device, which as good as new in terms of wear and cleanliness.

The wing and socket connection in the pump or motor of the invention can be designed in a number of different ways, such as in US Pat 5 shown. In the embodiment of 5 is the wing 22 just designed while the socket 41 with rotating jaws 82 equipped, which form a hinge at the opening of the base. The turning jaws 82 form a channel of uniform width, attached to the wing 22 adjusted so that the wing can slide transversely to the rotary jaws while rotor 20 circles.

Although a description has been given of a particular embodiment, it is understood that various changes could be made without departing from the scope of the present invention. Accordingly, it is provided see that the invention is limited only in terms of the appended claims.

By doing the performance of the pump embodiment described same embodiment the engine function through when fluid pressure at the inlet opening is applied, with less pressure at the outlet, whereby a torque is applied to the rotor, that in the rotation of the rotor results.

Claims (25)

Rotary pump or motor comprising a housing ( 16 ) having a cylindrical, inner peripheral wall defining a cavity, a rotor ( 20 ) with a cylindrical peripheral surface and a base ( 41 ) lying inside said peripheral surface, said rotor ( 20 ) is arranged eccentrically in the cavity and is adapted to roll the inner peripheral surface in close proximity thereto, the inner circumferential wall and the rotor peripheral surface defining therebetween a working chamber (12); 18 ), whereby the housing ( 16 ) a wing ( 22 ) with one end in the socket ( 41 ), so that the wing ( 22 ) within the socket ( 41 ) slides and receives in between a predetermined liquid tightness, and the rotor ( 20 ) is able to circulate within the cavity, wherein the housing ( 16 ) an inlet opening ( 24 ) adjacent to one side of the wing ( 22 ) and an outlet opening ( 26 ) adjacent to the other side of the wing ( 22 ) and both openings are in fluid communication with the cavity via the inner peripheral wall, wherein the wing ( 22 ) has a uniform thickness and is rigidly fixed to the housing, characterized in that the base ( 41 ) an opening with rotary jaws ( 42 ) and is received between the jaws to a pivot ( 42 ), which makes the sliding of the wing ( 22 ) by the hinge and swinging of the wing together with the hinge, while maintaining the liquid-tightness. Rotary pump or motor according to claim 1, further comprising a sealing barrier ( 35 ) disposed between the rotor surface and the inner peripheral wall and adapted, fluid communication between the inlet port ( 24 ) and the outlet opening ( 26 ), when the rotor ( 20 ) is in roll coverage with the inlet opening or the outlet opening or any point therebetween. Rotary pump or motor according to claim 2, wherein the sealing barrier ( 35 ) is arranged adjacent to one of said inlet or outlet openings. Rotary pump or motor according to claim 3, wherein a second sealing barrier ( 35 ) is arranged adjacent to the second of said inlet or outlet openings. Rotary pump or motor according to claim 2, wherein the sealing barrier ( 35 ) on the housing ( 16 ) is attached. Rotary pump or motor according to claim 2, wherein the sealing barrier ( 35 ) on the rotor ( 20 ) is attached. Rotary pump or motor according to claim 2, wherein the sealing barrier ( 35 ) is made of elastic material. Rotary pump or motor according to claim 2, wherein the sealing barrier ( 35 ) as cooperating teeth ( 43 ) is formed on the inner peripheral wall and on the rotor peripheral surface. Rotary pump according to claim 1, further comprising a bypass channel with an inlet in communication with the inlet opening ( 24 ), an outlet in communication with the outlet opening ( 26 ) and a one-way valve ( 34 ) disposed between the inlet and the outlet to permit fluid flow from the inlet to the outlet bypassing the pumping chamber (US Pat. 18 ). Rotary pump according to claim 9, wherein the bypass channel in the housing ( 16 ) is integrated. Rotary pump according to claim 1, further comprising a pulsation damper ( 64 ) connected to the outlet opening ( 26 ) connected is. Rotary pump according to claim 1, in a pump device further comprising a drive unit ( 14 ), which is adapted to the rotor ( 20 ) by means of an eccentric drive element ( 52 ) to drive. A pump according to claim 12, wherein the pump is connected to the drive unit (10). 14 ) and detachable from it. A pump according to claim 13, wherein the pump and the drive unit ( 14 ) are constructed so that the fastening of the pump to the drive unit ( 14 ) simultaneously with the engagement of the rotor ( 20 ) in the eccentric drive element ( 50 . 52 ) leads. Pump according to claim 14, comprising fastening means ( 70 . 72 ), which allow attachment through simple operation without tools. A pump according to claim 14, wherein the rotor ( 20 ) a concentric socket ( 44 ), the eccentric drive element ( 50 . 52 ) an eccentric crank ( 52 ), which is adapted to rotate in the concentric base ( 44 ) when the pump unit on the drive unit ( 14 ), thereby providing the engagement and the housing ( 16 ) an opening ( 36 ), which allows the crank ( 52 ), in the concentric socket ( 44 ) to penetrate. A pump according to claim 16, wherein the crank ( 52 ) a warehouse ( 54 ) permanently attached thereto, the bearing ( 54 ) provides the rotationally movable seat of the crank to the concentric socket. A pump according to claim 17, wherein the crank ( 52 ) a conical head ( 78 ) and having a diameter and eccentricity such that the conical head ( 78 ) during mounting in the concentric base ( 44 ), regardless of the orientation between the concentric socket ( 44 ) and the crank ( 52 ) before fixing. Pump according to claim 13, wherein the pump is made of materials suitable for its use are suitable as a disposable unit. Rotary pump according to claim 1, wherein the rotor ( 20 ) by a drive unit ( 14 ) via an eccentric drive element ( 50 . 52 ) is rotatable, wherein the drive unit ( 14 ) Fastening means and the eccentric drive element ( 50 . 52 ) Engaging means, wherein the housing ( 16 ) Has fastening means which mate with the attachment means of the drive unit and the rotor comprises engagement means which mate with the engagement means of the eccentric drive member, wherein the housing ( 16 ) with the drive unit ( 14 ) and detachable therefrom, such that the fastening of the housing to the drive unit by its attachment means permits simultaneous engagement of the rotor ( 20 ) in the eccentric drive element ( 52 ) is caused to rotate by its engaging means. A pump according to claim 20, wherein the attachment means ( 70 . 72 ) of the drive unit ( 14 ) and the housing ( 16 ) allow attachment by simple operation without tools. A pump according to claim 20, wherein the engagement means of the rotor ( 20 ) from a concentric base ( 44 ), wherein the engagement means of the eccentric drive element ( 14 ) an eccentric crank ( 52 ), which is adapted to rotate in the concentric base ( 44 ), when the pump unit on the drive unit ( 14 ), thereby providing the simultaneous engagement and the housing ( 16 ) an opening ( 36 ), which allows the crank ( 52 ), in the concentric socket ( 44 ) to penetrate. A pump according to claim 22, wherein the crank ( 52 ) a warehouse ( 54 ) permanently attached thereto, the bearing ( 54 ) provides the rotationally movable seat of the crank to the concentric socket. A pump according to claim 23, wherein the crank has a conical head ( 78 ) and having a diameter and eccentricity such that the conical head ( 78 ) during mounting in the concentric base ( 44 ), regardless of the orientation between the concentric socket ( 44 ) and the crank ( 52 ) before fixing. Pump according to claim 20, wherein the pump is made of materials suitable for its use are suitable as a disposable unit.