Diaphragm pump, and tank leak diagnosis module with a diaphragm pump

Abstract

The invention relates to a diaphragm pump having a drive unit and delivery unit, wherein the drive unit has a drive shaft which protrudes from the drive unit at least partially into an interior space of the delivery unit and is mounted rotatably along the rotational axis, wherein the interior space is delimited by a housing comprising a maximum of four first housing parts and a maximum of four second housing parts, wherein at least one diaphragm is arranged in the interior space in such a way that the interior space is divided by the at least one diaphragm into an eccentric chamber and at least one delivery chamber, wherein the diaphragm is connected via a transmission means to the drive shaft, wherein each first installation direction of the maximum of four first housing parts is oriented parallel or perpendicularly with respect to the rotational axis, wherein each first installation direction is oriented parallel to each further first installation direction, and each second installation direction of the maximum of four second housing parts is oriented substantially perpendicularly with respect to the first installation direction, and to a tank leak diagnosis module with a diaphragm pump of this type.

Description

[0001] Diaphragm pump and tank leakage diagnostic module with a diaphragm pump

[0002] The present invention relates to a diaphragm pump comprising a drive unit and a delivery unit, wherein the drive unit has a drive shaft which projects at least partially from the drive unit into an interior of the delivery unit and is rotatably mounted along a rotation axis, wherein at least one diaphragm is arranged in the interior such that the interior is divided by the at least one diaphragm into an eccentric space and at least one delivery space, wherein the diaphragm is connected to the drive shaft via transmission means, as well as a tank leakage diagnostic module with a diaphragm pump.

[0003] Diaphragm pumps are manufactured in many designs and sizes and are used, for example, to generate compressed air. Diaphragm pumps feature, among other things, a drive unit with a drive shaft that cyclically moves two laterally arranged diaphragms. The air compressed by the diaphragm movement is transmitted via lines, particularly hoses, where flow rates of up to 500 l / min can be achieved.

[0004] Diaphragm pumps are also used in laboratory technology and healthcare, as the fluids being pumped, also referred to as the medium, are always separated from the moving parts of the drive unit, effectively preventing contamination. Diaphragm pumps are also used in the automotive industry, both as single and double diaphragm pumps. The diaphragms are moved by an eccentrically arranged ball bearing and a connected connecting rod. The connecting rod, often manufactured using an injection molding process, can surround the ball bearing by overmolding it. The operating temperature range for such diaphragm pumps is between -15°C and +80°C.

[0005] The disadvantages of ball bearings are their high cost and mass. The eccentric movement leads to high imbalance, increased noise, and increased wear. Ball bearings also require more space. The same applies to conventional connecting rods. Finally, the numerous sealing elements and check valves required to prevent leaks and ensure the pump function lead to complex and error-prone assembly due to their small size.

[0006] DE 10 2007 005 736 A1 discloses a positive displacement pump for conveying a fluid, comprising a pumping chamber with a variable volume, at least partially defined by a suction and displacement element, and at least one suction and outlet channel in flow communication with the pumping chamber for sucking in and discharging the fluid into and out of the pumping chamber. Furthermore, the positive displacement pump comprises a drive device for cyclically increasing and decreasing the current volume.

[0007] DE 10 2006 046 567 B3 discloses a diaphragm pump comprising a housing and diaphragms arranged at different levels therein, each of which is connected to a common eccentric shaft via a connecting rod. Working spaces are defined between the diaphragms and the housing, whose inlets and outlets are connected directly or indirectly via connections inside the housing.

[0008] The general disadvantage of the double diaphragm pumps known to date is the high manufacturing and assembly costs due to the large number of individual components that have to be connected to one another, as well as the complexity of the assembly, which often leads to defective products and rejects.

[0009] The relatively large installation space is also a disadvantage.

[0010] The present invention is therefore based on the object of proposing a diaphragm pump that is particularly intuitive to assemble, simple and compact and inexpensive to manufacture, as well as a tank leakage diagnostic module with such a diaphragm pump.

[0011] This object is achieved by a diaphragm pump comprising a drive unit and a delivery unit, wherein the drive unit has a drive shaft which projects at least partially from the drive unit into an interior space of the delivery unit and is rotatably mounted along a rotational axis, wherein the interior space is delimited by a housing comprising a maximum of four first housing parts and a maximum of four second housing parts, wherein at least one diaphragm is arranged in the interior space such that the interior space is divided by the at least one diaphragm into an eccentric space and at least one delivery space, wherein the diaphragm is connected to the drive shaft via transmission means, wherein each first installation direction of the maximum of four first housing parts is oriented parallel or perpendicular to the rotational axis,wherein each first installation direction is oriented parallel to each further first installation direction and each second installation direction of the maximum four second housing parts is oriented substantially perpendicular to the first installation direction.

[0012] In a particularly advantageous manner, two first housing parts and / or two second housing parts are arranged opposite one another. If the diaphragm pump has more than two diaphragms, the pairs of opposing second housing parts are then also arranged radially equidistant around the axis of rotation. The first and second housing parts are preferably made of a plastic, in particular of a glass fiber reinforced plastic such as polypropylene or polyamide. The formation of a single first housing part and a single second housing part or a single first housing part and a maximum of four second housing parts is also advantageous. The housing of the pumping unit protects the interior from unauthorized access and is fluidically connected to the environment at least temporarily.

[0013] The drive unit preferably comprises an electric motor, which is connected to a controller—in particular to an external control unit of a vehicle—via signal lines and / or power supply lines. In an advantageous embodiment, the tank leakage diagnostic module can also comprise a controller itself, with the diaphragm pump and controller being mounted, in particular, in a common module housing. The separation between the drive and delivery units also separates the electrical signal lines and / or power supply lines from the fluid line, which greatly reduces the risk of sparking and explosions, especially when the medium is a fuel-air mixture or similar.

[0014] The drive unit preferably has a substantially cylindrical shape along the axis of rotation, which leads to a compact arrangement next to the conveyor unit. In a particularly preferred embodiment, the basic dimensions of the drive unit do not exceed the basic dimensions of the conveyor unit. The drive shaft is designed to be substantially rotationally symmetrical to the axis of rotation. In one embodiment, the drive unit has, at its end facing the conveyor unit, a cylindrical shoulder with a reduced diameter and a flat surface for contact with the housing of the conveyor unit as a positioning means. The drive shaft passes through the shoulder centrally. The housing of the conveyor unit preferably has a through-opening through which the drive shaft and / or the shoulder pass, and through which at least the drive shaft projects into the interior.The through-opening has substantially the same diameter as the drive shaft or the shoulder. The through-opening is preferably arranged centered on a first housing part.

[0015] In an embodiment of the invention, it is provided that the through-opening has a contour which, in addition to the drive shaft, has positioning means, in particular the shoulder of the drive unit for centering the drive unit on the conveyor unit or for the force-locking and / or form-locking connection of the drive unit to the housing, which at least partially protrude into the interior or terminate at it.

[0016] The at least two diaphragms are preferably arranged radially equidistant from the rotational axis, so that with an oscillating movement of the diaphragms, which occurs through the transmission of the drive shaft movement via the transmission means, the medium to be pumped is pumped continuously and as evenly as possible through the diaphragm pump. This ensures a constant increase or decrease in pressure in a closed volume connected to the diaphragm pump. Pressure and flow velocity, as well as volumetric flow, can thus be precisely controlled. The more diaphragms installed within the diaphragm pump, the larger the maximum displacement volume, which increases performance at the same cost and in the same installation space. Pulsation in the flow rate is also reduced.

[0017] In a further development of the invention, it is provided that the maximum of four first housing parts and the maximum of four second housing parts are connected to one another in such a way that they form a positive and / or non-positive connection with their immediately adjacent first and / or second housing parts. In a particularly preferred embodiment of the invention, the maximum of four second housing parts are of the same shape, in particular identical. The first and second housing parts are further preferably arranged relative to one another in such a way that they mutually restrict at least five degrees of freedom. Accordingly, no further housing components are necessary to position the housing and to fix it in place. This advantageously enables very simple assembly and maintenance.

[0018] In an advantageous embodiment, the maximum of four first housing parts and / or at least one first housing part and one second housing part have interlocking positioning contours, wherein the first housing parts preferably have positioning pins or positioning bores and the second housing parts correspondingly have positioning bores or positioning pins. The positioning contours enable pre-positioning and pre-fixing of the components of the housing. The first housing parts are preferably designed such that they can only be mounted in a predefined orientation depending on the position of the second housing parts relative to the diaphragm pump, wherein the precise alignment between the first and second housing parts is defined in particular via the positioning contours. Incorrect assembly of the housing components, namely the first and second housing parts, is thus advantageously avoided.In addition, positioning contours such as positioning pins or holes can be easily produced during a manufacturing process, in particular during an injection molding process, so that no further production steps are necessary. In an advantageous embodiment, the positioning pins and holes are elliptical, polygonal, or circular in their cross-sectional area oriented perpendicular to their respective installation direction. In an embodiment of the invention, it is provided that the immediately adjacent first housing parts and / or second housing parts are at least partially connected by a plug-in, clamp-in, screw-in, weld-in, solder-in, or adhesive connection. Particularly preferred are integral connections, since in addition to simply fixing at least two housing components to one another, they also create a sealing connection between them, which in turn eliminates the need for additional seals.

[0019] Particularly advantageously, the interior space is divided by each additional membrane into a further delivery chamber, with the at least one membrane always being arranged between a delivery chamber and the eccentric chamber. The eccentric chamber is arranged concentrically to the rotational axis, with the delivery chambers each arranged radially equidistant around the eccentric chamber. Furthermore, the membranes are each arranged with their main surfaces parallel to the rotational axis.

[0020] In an advantageous development of the invention, the at least one diaphragm is clamped sealingly between a second housing part and at least one first housing part and / or the at least one diaphragm has the same second installation direction as the second housing part arranged sealingly against it. Both the first housing parts and the second housing parts have corresponding receptacles for at least one edge region of the diaphragm. The edge region of the diaphragm is designed here as a sealing bead which is received in a sealing groove formed by the first and second housing parts. This leads to secure positioning and forms a seal between the eccentric chamber and the conveying chamber. The sealing bead preferably has a circular or oval cross-section. The diaphragm itself also has a substantially circular or oval shape.In an advantageous embodiment of the invention, the at least one pumping chamber is defined by the diaphragm and a second housing part, and / or the eccentric chamber is defined by at least one diaphragm and a maximum of four first housing parts. This division of the interior space and arrangement of the components enables simple assembly and sealing of the pumping chamber. Pressure buildup and reduction, and thus the pumping of a medium, occur exclusively within the at least one pumping chamber.

[0021] In a further development of the invention, it is provided that the transmission means have at least one connecting rod, each concentrically positioned in the at least one diaphragm, and an eccentric that is rotationally connected to the at least one connecting rod, wherein the connecting rod is at least partially surrounded by the at least one diaphragm, wherein the eccentric is rotationally fixedly connected to the drive shaft, wherein the connecting rod, eccentric and drive shaft are arranged in the eccentric space. The rotationally fixed connection between the eccentric and drive shaft is realized via a force or form fit. The connecting rod advantageously has a through-bore through which an eccentric pin of the eccentric, which is arranged eccentrically to the axis of rotation can be inserted. A bearing, in particular a plain bearing, is particularly advantageously formed between the eccentric pin and the through-bore, so that a purely rotational relative movement takes place between the two components.To further improve the sliding properties between the eccentric pin and the connecting rod, the connecting rod can have a plain bearing bushing that is pressed into the through-bore on one side and held in position by a radial web. Overmolding the plain bearing bushing with the connecting rod during the connecting rod manufacturing process is also advantageous. In a further development of the invention, the connecting rod is made of a material that has sufficient sliding properties. Between the connecting rod and the eccentric, the rotary motion arriving from the drive shaft is converted into a substantially translational motion, which is then transmitted to the diaphragm. The diaphragm is set into an oscillating vibration motion.The overmolding of the connecting rod with a preferably elastic material of the diaphragm is advantageously carried out during a primary forming of the diaphragm so that they are positively connected to one another, which simplifies assembly and further reduces the number of components of the entire diaphragm pump.

[0022] The eccentric is connected to the drive shaft in a rotationally rigid manner at its end opposite the eccentric pin, in particular by means of a longitudinal interference fit, so that a rotational movement of the drive shaft is transmitted to the eccentric essentially without loss. For this purpose, the eccentric has, in particular, a blind hole into which the drive shaft can be inserted. The blind hole is arranged concentrically within the upper region of the eccentric. The blind hole preferably has a polygonal cross-section so that the drive shaft is held therein, in particular by plastic deformation of the eccentric. The circumferential surface of the blind hole can additionally or alternatively have longitudinal teeth or knurling to enlarge the surface and increase the surface roughness. In addition, a high surface roughness of the drive shaft at the connection point to the eccentric - in particular by knurling - is provided in one embodiment.

[0023] The installation space of the eccentric chamber allows the installation of at least one connecting rod perpendicular to the rotation axis, with a radius of the eccentric chamber being defined in particular by the vertical extension of the connecting rod. Furthermore, the drive shaft or the eccentric is designed to be axially long enough that several connecting rods can be pushed onto the eccentric pin when using several diaphragms. The connecting rod is axially fixed to the eccentric pin, in particular via a retaining ring arranged on the eccentric pin. Due to the low eccentric mass, counterweights can be eliminated, which reduces the number of parts and thus the complexity of the diaphragm pump. The delivery chamber has at least such an extension in the radial direction that the diaphragm can execute an oscillating movement without touching the second housing part.

[0024] The connecting rods are preferably designed such that they have a step within their leg facing the eccentric, which does not impair the force absorption of the connecting rods and allows them to be mounted very compactly on the eccentric. The connecting rod is particularly L-shaped. For example, it can have a leg length between the rotation axis and the diaphragm of a maximum of 20 mm, preferably 15 mm, particularly preferably 10 mm. With these dimensions, the installation space is as small as possible, but the stroke generated by the offset of the eccentric pin on the drive shaft, transmitted via the connecting rod, and arriving at the diaphragm is large enough to generate the required volume flow.

[0025] Furthermore, the at least one diaphragm is advantageously formed integrally with at least one check valve. This allows all components made of the same material to be made in one piece, simplifying the manufacturing process, assembly, and maintenance. The at least one check valve is preferably a flutter valve. The diaphragm and the at least one check valve are advantageously formed from a rubber, in particular NBR or EPDM. Accordingly, a single component performs a total of three functions: conveying, sealing, and opening / closing. The check valve preferably has a thinner material than the diaphragm.

[0026] In an advantageous embodiment of the invention, at least one conveying line for conveying a medium, in particular ambient air, is formed in at least one first housing part and / or in each of the second housing parts. With such a design and integration of the conveying line into the first and second housing parts, no additional components such as hose lines are necessary. The conveying lines are advantageously integrated into the first and second housing parts in such a way that they enable the conveyance of the medium with as little loss as possible. Accordingly, the conveying lines have, in particular, a constant or evenly rising and falling cross-section.The first and second housing parts have a wall thickness such that at least one conveying line is completely surrounded by the first or the second housing part, with inlets and outlets of the conveying lines being formed on the outer surfaces of the first and second housing parts. The wall thickness of the first and / or second housing part is a maximum of 2 times, preferably a maximum of 1.5 times, particularly preferably a maximum of 1.2 times the diameter of the conveying line. The conveying lines can be formed in particular during a primary forming process of the first and second housing parts or subsequently by a machining process. The conveying lines advantageously connect the conveying chambers with an environment, with a check valve being arranged between the conveying chambers and the environment within each of the conveying lines.The conveying lines adjacent to the individual conveying chambers are at least partially combined, in particular within a first housing part, to form a common conveying line. In a further development of the invention, the housing has clamping arms and / or clamping pins projecting away from the interior at least for positioning the conveying unit on the drive unit. The clamping arms and / or the clamping pins are oriented substantially parallel to the axis of rotation. The clamping arms can have a hook at their ends pointing away from the conveying unit, which hook can be inserted into a socket arranged on the drive unit. In a particularly advantageous embodiment, the clamping arms are arranged radially equidistant around the axis of rotation, such that the drive unit can be plugged onto the conveying unit.The provision of clamping pins on the housing, which can be inserted into corresponding clamping holes in the drive unit, is also advantageous in order to also achieve positioning between the drive and conveyor units. In one embodiment of the invention, the drive unit and the conveyor unit have corresponding clamping holes or sockets and analogous clamping pins or clamping arms for mutual positioning. Furthermore, or alternatively, the drive and conveyor units are connected to each other in a force-fitting manner, in particular by means of at least one screw, in order to ensure a reliable connection between both units during operation and the resulting vibrations.

[0027] The present object is further achieved by a tank leakage diagnostic module for detecting a leak in a tank of fuel-powered vehicles, comprising a module housing formed from at least one module housing part and at least one module housing cover, wherein these enclose a module interior, wherein the module interior has a pump area, a valve area and an electronics area, wherein the electronics area is at least partially positioned in the at least one module housing cover, wherein a diaphragm pump according to the invention is arranged in the pump area and a valve is arranged in the valve area fluidically parallel to the diaphragm pump.

[0028] The module housing itself is advantageously arranged between an air filter and a tank with an upstream activated carbon canister of a vehicle and is fluidically connected to them. In a preferred embodiment, the valve is designed as a two-way valve and arranged in a first module line of the tank leakage diagnostic module. The diaphragm pump according to the invention is fluidically arranged parallel to the valve in a second module line. Furthermore, a check valve is preferably arranged in series with the diaphragm pump in the second module line and parallel to the valve, wherein, in a particularly advantageous embodiment, a pressure equalization valve is arranged in a third module line parallel to these three. All module lines are at least partially accommodated in the module interior.In a passive mode of the tank leak diagnostic module, the valve is open, allowing a medium, particularly ambient air, to escape from the tank to the air filter during a refueling process. In an active mode, the valve is closed, particularly after the vehicle's engine is switched off, and the diaphragm pump generates an overpressure in the tank compared to the ambient air pressure. The pressure sensor, which is located on the vehicle, in particular inside the tank leak diagnostic module or outside the tank leak diagnostic module, measures the pressure inside the tank during a diagnostic phase in order to detect a leak.The use of the diaphragm pump in the tank leakage diagnostic module is particularly advantageous because, thanks to its simple assembly and few components, it is very reliable and durable, and it takes up very little space, which in turn influences the installation space of the tank leakage diagnostic module. The diaphragm pump is advantageously fixed by screws within the module housing, with the housing of the delivery unit having fastening tabs for this purpose, in particular for receiving the screws. In a further development of the invention, it is provided that a pressure sensor is arranged in the electronics area, with the pressure sensor being fluidly connected to the valve on the tank side via a riser pipe arranged at least partially in the valve area.The advantage here is that the best possible separation is achieved between electronic components in the electronics area and fluid-carrying components in the valve and pump area, which simplifies maintenance and reduces possible damage and failures.

[0029] The invention is described by way of example in a preferred embodiment with reference to the figures, wherein further advantageous details can be taken from the figures.

[0030] Functionally identical parts are provided with the same reference symbol.

[0031] The figures show in detail:

[0032] Figure 1 Side view of a diaphragm pump with a delivery unit in section;

[0033] Figure 2 Exploded view of the conveyor unit in section;

[0034] Figure 3 Side view of the conveying unit in section in the area of ​​the suction-side conveying line;

[0035] Figure 4: Side view of the delivery unit in section in the area of ​​the pressure-side delivery line; Figure 5: First side view of a tank leakage diagnostic module with diaphragm pump in section;

[0036] Figure 6 Second side view of a tank leakage diagnostic module with diaphragm pump in section.

[0037] Figure 1 shows a side view of a diaphragm pump 1 with a delivery unit 3 in section, wherein a drive unit 2 lies alongside the delivery unit 3 along a rotation axis 6. The drive unit 2 has a drive shaft 4 which projects into an interior space 5 of the delivery unit 3. To introduce the drive shaft 4 into the interior space 5, the delivery unit 3 has a through-opening 28 into which positioning means 29, here formed by a cylindrical shoulder of the drive unit 2, are introduced such that they are coaxially aligned with one another, in particular are pressed together in a sealing manner. The through-opening 28, the positioning means 29 and the drive shaft 4 are oriented concentrically to the rotation axis 6. The through-opening 28 is arranged within a first housing part 8a of a housing 7 of the delivery unit 3.Another first housing part 8b is also arranged along the rotation axis 6 at the end of the first housing part 8a opposite the drive unit 2. Two membranes 10 are arranged radially equidistant from the rotation axis 6, wherein said membranes have a sealing bead 30 on their radially outer edges, which is received in a sealing groove 31 formed by the first housing parts 8a, 8b and a second housing part 9. The membranes 10 are essentially circular and are held between the first housing parts 8a, 8b and second housing parts 9 in such a way that they divide the interior space 5 into an eccentric chamber 11 and two conveying chambers 12. The drive shaft 4 is arranged in the eccentric chamber 11 and pressed with an eccentric 20. The eccentric 20 has an eccentric pin 32 arranged eccentrically to the rotation axis 6, on which connecting rods 19, which are overmolded by the membrane 10, are arranged in a rotationally movable manner.The eccentric 20 and the connecting rods 19 form transmission means 13 for translating a rotary movement of the drive shaft 4 into an oscillating, at least partially translational movement of the diaphragm 10. Plain bearing bushings 33 are arranged between the connecting rod 19 and the eccentric 20 in order to keep wear during a relative movement between the eccentric pin 32 and the connecting rod 19 as low as possible. Apart from the diaphragm 10, no further sealing means are provided or necessary within the delivery unit 3, so that the number of components and thus the complexity and susceptibility to errors are significantly reduced. One of the possible assembly sequences of the diaphragm pump 1 according to the invention is described below. As a first step, the adjacent first housing part 8a is placed onto the drive unit 2 in a centered manner along a first installation direction 14, so that the drive shaft 4 protrudes through the through-opening 28.Subsequently, the transmission means 13 are mounted on the drive shaft 4 along the first installation direction 14, i.e. the eccentric 20 is pressed on, the plain bearing bushing 33 is pushed onto the eccentric pin 32, and the connecting rods 19 are attached to the plain bearing bushing 33. The plain bearing bushing 33 is formed in two parts, with one part being pushed onto the eccentric pin 32 in front of the connecting rod 19 and one part after it. Subsequently, a snap ring (not shown) is mounted on the eccentric pin 32 to prevent the connecting rods 19 and plain bearing bushing 33 from slipping out. The connecting rods 19 were already overmolded by the diaphragm 10 before the diaphragm pump 1 was assembled, so that they are already assembled and their sealing bead 30 is received in a sealing groove 31 partially formed by the first housing part 8a.The eccentric chamber 11 is then closed by attaching another first housing part 8b along the first installation direction 14 onto the first housing part 8a. Finally, the first of the second housing parts 9 is attached in a second installation direction 15, followed by the second of the second housing parts 9. The latter can also take place simultaneously. This locks the first housing parts 8a, 8b in all degrees of freedom. The two second housing parts 9 have opposing second installation directions 15, 15', each of which is oriented perpendicular to the first installation directions 14. Finally, the second housing parts 9 are each screwed to at least one of the first housing parts 8a, 8b in order to also limit these in all degrees of freedom.

[0038] Figure 2 shows an exploded view of the conveyor unit 3 in section, with a part of the drive unit 2 at least indicated. The drive unit 2 has, at its end facing the conveyor unit 3, positioning means 29 and a drive shaft 4, both of which are arranged concentrically to the axis of rotation 6. The first housing part 8a of the conveyor unit 3, which rests against the drive unit 2, has clamping arms 23 pointing towards the drive unit 2 along the axis of rotation 6, which clamping arms ensure at least one positioning between the drive unit 2 and the conveyor unit 3. Concentric to the axis of rotation 6, this first housing part 8a has a through-opening 28 into which the positioning means 29 can be inserted and connected in a force-fitting manner. For reliable pressing, the through-opening 28 has radially equidistantly distributed vanes 34.The first housing parts 8a, 8b have positioning contours 16 on their mutually facing sides in order to reliably position the first housing parts 8a, 8b against one another during installation in a first installation direction 14. The first housing part 8b, which is further away from the drive unit 2, further has two conveyor lines 22, of which only one can be seen in Fig. 2, however, whereby the conveyor line 22 has a seal 35 radially surrounding it. The second conveyor line 22, not visible, is behind the plane of illustration in Fig. 2. The first housing part 8a, which is closer to the drive unit 2, is fastened to the drive unit 2 by means of a screw 36 in addition to the clamping arms 23. The eccentric 20 is slipped onto an end of the drive shaft 4 projecting towards the conveyor unit 3 along the first installation direction 14.For this purpose, the eccentric has a blind hole 37 with radially equidistantly distributed webs running along the rotation axis 6 in order to create a reliable non-positive connection between the eccentric 20 and the drive shaft 4. The eccentric pin 32 is designed eccentrically to the rotation axis 6 and has a locking groove 38 at its end pointing away from the drive shaft 4 for receiving a locking ring 39. The connecting rods 19, which are partially overmolded by the diaphragm 10, are pushed onto the eccentric pin 32 along the first installation direction 14 and are axially secured by means of the locking ring 39. For this purpose, the connecting rods 19 have bores with plain bearing bushes 33 arranged therein. Furthermore, the connecting rods 19 have an L-shaped cross-section such that their contours correspond to one another and they can be placed on top of one another with as little gap as possible in order to obtain a space-saving yet stable assembly.The overmolded parts of the connecting rods 19 each have a substantially circular shape and extend substantially parallel to the rotational axis 6 and within the basic dimensions of the diaphragm 10. The diaphragm 10 has a sealing bead 30 in its edge region, which is clamped sealingly between the first housing parts 8a, 8b and the second housing parts 9 during installation along a second installation direction 15. The second housing parts 9 also have positioning contours 16 in the form of positioning pins 17, which can be inserted into corresponding, invisible positioning bores in the first housing parts 8a, 8b in order to fix the second housing parts 9 to the first housing parts 8a, 8b during installation along the second installation direction 15.By installing the first housing parts 8a, 8b and the second housing parts 9 in different first and second installation directions 14, 15 oriented perpendicular to one another, the degrees of freedom of the first housing parts 8a, 8b are restricted via the second housing parts 9 in such a way that disassembly opposite to the first installation direction 14 is only possible when the second housing parts 9 are disassembled opposite to the respective second installation direction 15. Thus, by this arrangement of the installation directions 14, 15 and in particular by the arrangement of the positioning contours 16, the first housing parts 8a, 8b and the second housing parts 9 are restricted in at least five of their degrees of freedom; more precisely, the first housing parts 8a, 8b are restricted in all six degrees of freedom and the second housing parts 9 in five degrees of freedom, with the installation direction 14 forming the last remaining, unrestricted degree of freedom.

[0039] Figure 3 shows a side view of the delivery unit 3 in section in the area of ​​the suction-side delivery lines 22, which are brought together in the first housing part 8b, which is remote from the drive unit 2, in order to transport a medium via an inlet 40 and the suction-side delivery lines 22 into the respective delivery chamber 12. Depending on the position of the eccentric pin 32 and thus of the connecting rod 19, the volumes of the delivery chambers 12 are alternately expanded and compressed. During expansion of the delivery chambers 12, a negative pressure is created in them. This negative pressure is balanced out by a medium introduced into the delivery chamber 12 through the suction-side delivery line 22. A check valve 21 formed by the diaphragm 10, which is designed as a flutter valve, prevents backflow of the sucked-in medium. The check valve 21 also has a sealing bead 30 around its circumference.The delivery line 22 is formed entirely by the housing 7 of the delivery unit 3, so that additional hoses or lines are not necessary. The check valve 21 rests against a sealing elevation 41 of the first housing part 8b within the suction-side delivery line 22. The second housing parts 9 are designed in the area of ​​the check valves 21 on the suction-side delivery line 22 in such a way that they form a free space 46 for the movement of the check valve 21 into the delivery line 22 of the second housing parts 9. Within the free space 46, stop webs are formed, which create a stop for the check valve 21 in order to prevent excessive deformation and potential damage to it. The diaphragm 10 has a wave shape with a rolled fold so that tensile and compressive stresses on the diaphragm occurring during an oscillating movement during operation are as low as possible, which prevents material fatigue.The rolled fold preferably has the smallest possible wall thickness to increase flexibility.

[0040] Figure 4 shows a side view of the delivery unit 3 in section in the region of the pressure-side delivery line 22 and thus a representation plane that lies behind the representation plane of Figure 3. Analogous to the suction-side delivery line 22 explained in Figure 3, the membrane 10 on the pressure-side delivery line 22 is designed such that it has a check valve 21 for interrupting the pressure-side delivery line 22. However, the first housing part 8b and second housing parts 9 are designed in the region of the pressure-side check valve 21 such that the first housing part 8b forms a free space 46 for moving the check valve 21 into the delivery line 22 of the first housing part 8b and the second housing parts 9 each have a sealing elevation 41 to ensure a reliable seal between the second housing part 9 and the check valve 21.Accordingly, if the invisible eccentric pin 32 and thus a corresponding invisible connecting rod 19 are in a position in which the delivery chamber 12 is compressed, the medium contained therein is transported out of the delivery unit 3 via the pressure-side delivery line 22. The check valves 21 prevent the medium from returning to the delivery chamber 12. The arrangement of the delivery chambers 12, delivery lines 22, and check valves 21 shown in Fig. 3 and Fig. 4 defines a clear direction of the volume flow. An opposing arrangement of the diaphragms 10 is particularly advantageous, since in this case one delivery chamber 12 experiences compression and the other expansion, thus creating the most constant and uniform volume flow possible.

[0041] Figure 5 shows a first side view of a tank leakage diagnostic module 25 with a diaphragm pump 1 in section, wherein the diaphragm pump 1 is completely accommodated in a module interior 52 of a module housing 42 of the tank leakage diagnostic module 25, wherein the module housing 42 is formed by a module housing part 50 and two module housing covers 51a, 51b. The housing 7 of the delivery unit 3, more precisely the first housing part 8a arranged closer to the drive unit 2, has fastening tabs 43 through which screws 36 can be guided and screwed into the module housing 42. The seals 35 of the diaphragm pump 1 are also accommodated in the module housing 42, so that the medium flowing into or out of the delivery lines 22 is carried further in the module housing 42. The module housing 42 is designed in three parts, so that the diaphragm pump 1 can be easily inserted into it.The three parts of the module housing 42 are welded together after the components are fully assembled, creating a tight, materially sealed connection. The three parts of the module housing 42 can also be connected to each other using press, screw, adhesive, or clip connections. This side view also shows the sectional planes AA and BB, which show the side views in section in Figures 3 and 4.

[0042] Figure 6 shows a second side view of a tank leakage diagnostic module 25 with a diaphragm pump 1 in section, wherein a module interior 52 of the module housing 42 is divided into a pump area 44, a valve area 45, and an electronics area 49, wherein the diaphragm pump 1 is arranged within the pump area 44, and a valve 26 and a riser pipe 47 are arranged within the valve area 45. A pressure sensor 48 is arranged in the electronics area 49, which is fluidically connected to the valve 26 on the tank side via the riser pipe 47 in order to measure a static pressure within the tank. The electronics area 49 is at a maximum distance from fluid-carrying components of the tank leakage diagnostic module 25 and is arranged within a module housing cover 51a. This avoids mutual interference.The entire tank leakage diagnostic module 25 is particularly compact and constructed with the smallest possible number of individual components, making it cost-effective, robust and versatile.

[0043] LIST OF REFERENCE SYMBOLS

[0044] diaphragm pump

[0045] drive unit

[0046] conveyor unit

[0047] drive shaft

[0048] Interior

[0049] rotation axis

[0050] Housing a, 8b First housing part

[0051] Second housing part 0 Diaphragm 1 Eccentric chamber 2 Delivery chamber 3 Transmission means 4 First installation direction 5, 15' Second installation direction 6 Positioning contours 7 Positioning pin 9 Connecting rod 0 Eccentric 1 Check valve 2 Delivery line 3 Clamping arms Clamping pin

[0052] Tank leak diagnostic module

[0053] valve

[0054] passage opening

[0055] Positioning devices

[0056] sealing bead

[0057] Sealing groove

[0058] Eccentric pin

[0059] Plain bearing bushings

[0060] wing

[0061] seal

[0062] screw

[0063] blind hole

[0064] locking groove

[0065] retaining ring

[0066] inlet

[0067] Density increase

[0068] Module housing

[0069] Mounting tabs

[0070] Pump area

[0071] Valve area

[0072] Free space

[0073] Riser pipe pressure sensor electronics area module housing part a, 51 b module housing cover module interior

[0074] PATENT CLAIMS Diaphragm pump (1) comprising a drive unit (2) and a delivery unit (3), wherein the drive unit (2) has a drive shaft (4) which projects at least partially from the drive unit (2) into an interior space (5) of the delivery unit (3) and is rotatably mounted along a rotational axis (6), wherein the interior space (5) is delimited by a housing (7) comprising a maximum of four first housing parts (8a, 8b) and a maximum of four second housing parts (9), wherein at least one diaphragm (10) is arranged in the interior space (5) such that the interior space (5) is divided by the at least one diaphragm (10) into an eccentric space (11) and at least one delivery space (12), wherein the diaphragm (10) is connected to the drive shaft (4) via transmission means (13), wherein each first installation direction (14) of the maximum of four first housing parts (8a, 8b) is oriented parallel or perpendicular to the rotational axis (6),wherein each first installation direction (14) is oriented parallel to each further first installation direction (14) and each second installation direction (15) of the maximum four second housing parts (9) is oriented substantially perpendicular to the first installation direction (14). Diaphragm pump (1) according to claim 1, characterized in that the maximum four first housing parts (8a, 8b) and the maximum four second housing parts (9) are connected to one another in such a way that they form a positive and / or non-positive connection with their immediately adjacent first and / or second housing parts (8a, 8b, 9). Diaphragm pump (1) according to claim 1 or 2, characterized in that the maximum four first housing parts,

Claims

PATENT CLAIMS 1. A diaphragm pump (1) comprising a drive unit (2) and a delivery unit (3), wherein the drive unit (2) has a drive shaft (4) which projects at least partially from the drive unit (2) into an interior space (5) of the delivery unit (3) and is rotatably mounted along a rotation axis (6), wherein the interior space (5) is delimited by a housing (7) comprising a maximum of four first housing parts (8a, 8b) and a maximum of four second housing parts (9), wherein at least one diaphragm (10) is arranged in the interior space (5) such that the interior space (5) is divided by the at least one diaphragm (10) into an eccentric space (11) and at least one delivery space (12), wherein the diaphragm (10) is connected to the drive shaft (4) via transmission means (13), wherein each first installation direction (14) of the maximum of four first housing parts (8a, 8b) is oriented parallel or perpendicular to the rotation axis (6),wherein each first installation direction (14) is oriented parallel to each further first installation direction (14) and each second installation direction (15) of the maximum four second housing parts (9) is oriented substantially perpendicular to the first installation direction (14).

2. Diaphragm pump (1) according to claim 1, characterized in that the maximum four first housing parts (8a, 8b) and the maximum four second housing parts (9) are connected to one another in such a way that they form a positive and / or non-positive connection with their immediately adjacent first and / or second housing parts (8a, 8b, 9).

3. Diaphragm pump (1) according to claim 1 or 2, characterized in that the maximum four first housing parts (8a, 8b) and / or at least one first housing part (8a, 8b) and one second housing part (9) have interlocking positioning contours (16), wherein preferably the first housing parts (8a, 8b) have positioning pins (17) or positioning bores and the second housing parts (9) have corresponding positioning bores or positioning pins (17).

4. Diaphragm pump (1) according to one of the preceding claims, characterized in that the immediately adjacent first housing parts (8a, 8b) and / or second housing parts (9) are at least partially connected by a plug-in, clamp-in, screw-in, weld-in, solder-in or adhesive connection.

5. Diaphragm pump (1) according to one of the preceding claims, characterized in that the interior (5) is divided by each further diaphragm (10) by a further delivery chamber (12), wherein the at least one diaphragm (10) is always arranged between a delivery chamber (12) and the eccentric chamber (11).

6. Diaphragm pump (1) according to one of the preceding claims, characterized in that the at least one diaphragm (10) is clamped sealingly between a second housing part (9) and at least one first housing part (8a, 8b) and / or the at least one diaphragm (10) has the same second installation direction (15) as the second housing part (9) arranged sealingly on it.

7. Diaphragm pump (1) according to one of the preceding claims, characterized in that the at least one delivery chamber (12) is formed by the diaphragm (10) and one of the maximum four second housing parts (9) and / or the eccentric space (11) is delimited by at least one membrane (10) and the maximum four first housing parts (8a, 8b).

8. Diaphragm pump (1) according to one of the preceding claims, characterized in that the transmission means (13) have at least one connecting rod (19) which is concentrically positioned in the at least one diaphragm (10) and an eccentric (20) which is connected in a rotationally movable manner to the at least one connecting rod (19), wherein the connecting rod (19) is at least partially overmolded by the at least one diaphragm (10), wherein the eccentric (20) is connected in a rotationally fixed manner to the drive shaft (4), wherein the connecting rod (19), eccentric (20) and drive shaft (4) are arranged in the eccentric space (11).

9. Diaphragm pump (1) according to one of the preceding claims, characterized in that the at least one diaphragm (10) is formed integrally with at least one check valve (21).

10. Diaphragm pump (1) according to one of the preceding claims, characterized in that in at least one first housing part (8a, 8b) and / or in the second housing parts (9) at least one delivery line (22) for conveying a medium is formed.

11. Diaphragm pump (1) according to one of the preceding claims, characterized in that the housing (7) has clamping arms (23) and / or clamping pins (24) projecting away from the interior (5) at least for positioning the delivery unit (3) on the drive unit (2).

12. Tank leakage diagnostic module (25) for detecting a leak in a tank of fuel-driven vehicles, comprising a module housing (42) formed from at least one module housing part (50) and at least one module housing cover (51a, 51b), wherein these enclose a module interior (52), wherein the module interior (52) has a pump area (44), a valve area (45) and an electronics area (49), wherein the electronics area (49) is at least partially positioned in the at least one module housing cover (51a), wherein a diaphragm pump (1) according to one of claims 1 to 11 in the Pump area (44) is arranged and a valve (26) in the valve area (45) is arranged fluidically parallel to the diaphragm pump (1).

13. Tank leakage diagnostic module (25) according to claim 12, characterized in that a pressure sensor (48) in the Electronics area (49) is arranged, wherein the pressure sensor (48) is fluidically connected to the valve (26) on the tank side via a riser pipe (47) arranged at least partially in the valve area (45).

Images