PUMP DEVICE, ESPECIALLY FOR MOBILE TRANSPORTATION

Description

[0001] The present invention relates to a mobile pumping device, in particular for use on mobile means of transport such as semi-trailers, tank trailers, tank semi-trailers, tank trucks, and trucks. The mobile pumping device comprises a rotary piston pump with a housing and two pump openings formed thereon, one of which serves as a pump inlet and the other as a pump outlet. Furthermore, at least two rotor units are rotatably accommodated in a pump chamber in the housing in order to pump a fluid from the pump inlet to the pump outlet. The mobile pumping device according to the invention is preferably used to pump liquids from the food sector, which may in particular also have increased viscosity values. For example, honey with a viscosity of approximately 10,000 can be bottled. The bottling of grape juice or olive oil, which has a viscosity of approximately 100, is also possible.Filling food ingredients or other liquids is also possible. If necessary, heating can be applied during filling to adjust the viscosity of the fluid to the desired range.

[0002] Various pumping devices for filling food or chemicals have become known in the prior art. For example, US 2,880,676 discloses a combination of a motor and a pump, wherein the pump is designed as a gear pump or rotary piston pump and comprises two counter-rotating pistons. The rotating pistons of the rotary piston pump are driven by intermeshing gears to which a drive pinion is connected. The motor is arranged vertically above the pump in order to keep the area below the motor hygienically clean. The known pumping device basically works and is easy to keep clean. However, such a pump-motor combination is not suitable for mobile use, as this known combination requires a lot of space. However, the available space is usually very limited, especially when used on tank trailers or trucks.

[0003] DE 20 2017 101 444 U1 discloses a mobile pumping device in which a drive shaft of a rotary piston pump is driven by a motor shaft of an electric motor. A standard electric motor is used, which is readily available in the event of a defect. This allows for very short-term replacement within one or two days, even in the event of a defect, since such electric motors are available in all regions with heavy goods traffic. This is important to ensure the smoothest possible operation and guarantee delivery deadlines.

[0004] EP 2 306 023 B1 discloses a pump device comprising a motor, a reduction gear, and a rotary lobe pump with selectable mounting options, which is also used in the mobile sector. In the known rotary lobe pump device, the electric drive motor is connected to a separate reduction gear. The reduction gear rotates on its output side at a speed that is lower than the speed of the motor. The output shaft of the reduction gear drives a drive shaft of the rotary lobe pump, which transmits the rotation to an intermediate shaft arranged parallel to it via coupled gears. The drive shaft and the intermediate shaft of the rotary lobe pump are each equipped with a rotary lobe and conduct the fluid to be pumped from the pump inlet to the pump outlet. In the rotary lobe pump, the drive force is distributed between the drive shaft and the intermediate shaft.The rotary lobe pump can be mounted on a mounting flange of the reduction gear in four positions, each offset by 90°, allowing the pump inlet and outlet to be oriented in different directions. The disadvantages of this known rotary lobe pump device are its elongated design and high overall weight, as the device includes not only the drive motor but also the reduction gear and the rotary lobe pump with the gearing for distributing the drive speed between the drive shaft and the intermediate shaft, as well as the actual rotary lobes.

[0005] DE 10 2018 105 723 A1 also discloses a pumping device for mobile vehicles comprising a drive motor and a rotary piston pump. A reduction gear is integrated into the rotary piston pump. A coupling for accommodating the drive motor is provided on the drive shaft of the rotary piston pump.

[0006] EP 2 602 428 A1 and WO 2017 / 066091 concern special designs of positive displacement pumps.

[0007] It is therefore the object of the present invention to provide a mobile pumping device, in particular for use on mobile means of transport such as semi-trailers, tank trailers, tank semi-trailers, tank trucks and lorries, as well as a mobile means of transport with a mobile pumping device, wherein the mobile pumping device enables reliable operation and easy replacement of defective parts, is small in size and has the lowest possible overall weight.

[0008] This object is achieved by a mobile pumping device having the features of claim 1 and by a mobile means of transport having the features of claim 13.Preferred developments of the invention are the subject of the dependent claims. Further advantages and features of the present invention will become apparent from the general description and the description of the exemplary embodiments.

[0009] A mobile pumping device according to the invention is particularly suitable and intended for use on mobile means of transport such as semi-trailers, tank trailers, tank semi-trailers, tank trucks, and trucks, and the like. The mobile pumping device comprises a drive motor and a rotary piston pump, wherein the drive motor has a motor shaft for driving the rotary piston pump and a motor housing.

[0010] The rotary piston pump has a housing with a pump housing part and a gear housing part, wherein two pump openings are formed on the pump housing part, one of which serves as a pump inlet and the other as a pump outlet. At least two rotor units are provided, rotatably received in a pump chamber in the pump housing, in order to convey a fluid, and in particular a liquid, from the pump inlet to the pump outlet. The two rotor units are rotatably mounted on rotor shafts (preferably outside the pump chamber) and are received there (in particular replaceably). Each rotor shaft is equipped with a rotor gear arranged outside the pump chamber. A drive pinion of a drive shaft of the rotary piston pump is coupled to one of the (and in particular exactly one of the) rotor gears, wherein the rotor gears and the drive pinion are accommodated in the gear housing part.The drive motor shaft has a recess at its front end, which accommodates the drive shaft of the rotary piston pump and is (rotationally) coupled to the drive shaft. The coupling can be achieved, for example, via a coupling device. Furthermore, the drive motor is connected to the housing via a connecting flange with a U-shaped cross-section. The connecting flange forms the rear end cover of the housing and, at the same time, the front end cover of the motor housing. The connecting flange comprises two parallel and spaced-apart flanges that form a circumferential "U" that opens outwards.

[0011] The mobile pump device according to the invention has many advantages. A significant advantage of the mobile pump device according to the invention is that a recess is provided on the motor shaft of the drive motor, allowing a compact coupling with the drive shaft of the rotary piston pump. In principle, a standard electric motor that can be delivered at short notice can be used. In the event of a defect, the motor shaft can be replaced or specially reworked. Delivery of a suitable motor shaft and on-site replacement is possible at short notice. Local machining of the motor shaft on-site is also possible, allowing for rapid replacement in the event of defects. This means that delivery promises can generally be met even if the electric motor is defective.

[0012] Another advantage is that the pumping device can be made even smaller. The fact that the motor shaft surrounds the drive shaft enables a particularly small and compact design. Furthermore, weight can be saved. In particular, the overall length of the mobile pumping device can also be reduced.

[0013] Preferably, both rotor gears have an identical number of teeth and are coupled to each other in counter-rotating directions. The teeth of the drive pinion mesh directly with the teeth of one of the rotor gears.

[0014] In particular, the drive pinion forms a reduction gear with the rotor gear, so that the rotor units rotate more slowly than the drive pinion. The drive shaft is designed to be coupled to a drive motor at a speed ratio of 1:1. In particular, the rotational axes of the rotor gears define a rotor plane, and a rotational axis of the drive pinion is arranged laterally spaced from the rotor plane.

[0015] Preferably, the motor shaft of the drive motor is coupled to the drive shaft via at least one coupling device with at least one coupling unit.

[0016] No separate intermediate reduction gear is required, to which the drive motor is flanged. The reduction gear is integrated into the rotary piston pump. To distribute the drive energy and ensure simultaneous rotation of both rotor units, the drive speed is transmitted via a drive pinion to a rotor gear on a rotor shaft. Because the two rotor gears are coupled to one another in counter-rotating directions, the rotation of one rotor shaft is transmitted to the other rotor shaft, so that both rotor units operate in opposite directions at the same speed, conveying the fluid to be pumped from the pump inlet to the pump outlet. A separate reduction gear stage is omitted, resulting in a significant weight saving.In one specific example, the total weight was reduced significantly, resulting in a reduction of more than 10%, 12%, or even 15%, or 17% compared to the previous state of the art, and in one specific example, by significantly more than 20 kilograms. With a total weight of approximately 125 kilograms, this represents a significant saving that contributes to a significant reduction in energy consumption in mobile means of transport.

[0017] In a configuration in which the drive shaft is arranged laterally spaced from the rotor plane defined by the rotational axes of the rotor gears, a significant reduction in height can be achieved in the direction of the rotor plane. The rotational axes of the rotor gears and the drive pinion form a triangle, thereby saving considerable installation space. The mobile pump device according to the invention is not only lighter but also more compact. Furthermore, even more installation length can be reduced. This opens up more application possibilities in often cramped vehicles.

[0018] In all embodiments, the rotational axes of the drive pinion and the rotor gears are preferably arranged parallel to each other. A reduction ratio from the drive pinion to the rotor gear, or a ratio of the number of teeth of the drive pinion and the rotor gear, is preferably less than 1:2 and in particular less than 1:2.5, and can also be less than 1:3, 1:4, or 1:8. Particularly preferably, it can be 1:5, 1:6, or 1:7.

[0019] In a preferred embodiment, a (vertical or perpendicular) projection of the drive pinion's axis of rotation onto the rotor plane spanned by the axes of rotation of the rotor gears is located between the axes of rotation of the rotor gears. This achieves a particularly compact design. Such a triangle spanned by the three axes of rotation has no interior angle greater than 90°, thereby achieving a particularly compact design. Both the height and the width of the pump device can be selected to be small.

[0020] Preferably, the drive pinion does not protrude beyond the upper edge of the highest of the two rotor units. This allows a particularly low overall height of the mobile pump device according to the invention to be achieved.

[0021] Preferably, the motor shaft comprises a coupling section at the front end of the motor shaft, where the recess is formed inside the motor shaft. The recess is formed, in particular, over the entire length of the coupling section and can define it.

[0022] The drive motor preferably comprises a motor housing. The coupling section can be arranged entirely outside the motor housing, but can also be arranged at least partially inside the motor housing.

[0023] The motor shaft comprises in particular a coupling section outside the motor housing and can comprise a second section in particular inside the motor housing (inner section).

[0024] Preferably, the coupling section of the motor shaft is defined by a cylindrical peripheral surface that bears against the motor shaft at least partially or almost completely. The outer surface of the motor shaft can be completely cylindrical, but can also be non-circular.

[0025] In particular, the recess forms a substantially cylindrical cavity. The inner circumference can be formed (in geometric terms, essentially) as a cylindrical cavity.

[0026] Preferably, the recess has at least one longitudinal groove. Two, three, or more longitudinal grooves may also be formed. In this case, the internal cross-section deviates from the cylindrical shape.

[0027] The recess may generally have a non-circular inner contour. e.g.An internal toothing may be formed. In particular, an external toothing is formed on the drive shaft, interacting with the internal toothing of the recess. The number of teeth may be the same or different, but in any case, they are designed to match each other.

[0028] Preferably, at least one coupling unit is included, which interacts with at least one coupling unit on the drive shaft and / or the motor shaft. Various separate coupling units or separate coupling parts or coupling contours can be provided and / or included.

[0029] In particular, at least one transverse opening extending (in particular at least substantially in the transverse direction or in the transverse direction) is formed in the drive shaft and / or the motor shaft, at which a rotationally fixed coupling of the drive shaft and the motor shaft is achieved via at least one coupling unit arranged therein. For example, a transverse hole can be formed into which a screw or a locking pin or coupling pin is inserted to achieve a rotationally fixed coupling.

[0030] Particularly preferably, a coupling unit or a type of spring is provided which can be introduced into the two axial grooves of the drive shaft and the motor shaft in order to achieve a rotationally fixed coupling of the motor shaft and the drive shaft.

[0031] Preferably, the drive pinion meshes directly with one of the rotor gears. It is also conceivable for the drive pinion to be coupled to the rotor gear via a chain or belt.

[0032] In particularly preferred developments, the drive motor is designed as an electric motor and can be driven in particular via three-phase current. The electric motor preferably has a power range between 1 kW and 15 kW. In particular, the electric motor has a power in the power range between 5 kW and 10 kW. In particular, the drive motor can be operated with a three-phase current connection or a high-voltage connection of an ordinary house or an industrial plant. Power levels of, for example, less than 7 kW or less than 8 kW are possible. However, it is also conceivable for a hydraulic motor to be used for the drive, which can in particular be driven, for example, by a hydraulic circuit of a mobile means of transport. Such a configuration has the advantage that no power connection or at least no high-voltage connection needs to be available.

[0033] According to the invention, the housing comprises a pump housing section and a gear housing section. The rotor gears and the drive pinion are housed in the gear housing section. The pump chamber with the rotor units is housed in the pump housing section.

[0034] According to the invention, the gear housing part and the pump housing part each have an (end) wall or partition wall. At least in the area of ​​the shaft bushings, a free space with a connection to the outside is preferably provided between the gear housing part and the pump housing part. This reliably prevents oil from passing from the gear housing part into the pump housing part and also prevents product to be filled into the pump housing part. Should a leak occur at a shaft bushing of a rotor shaft, the oil or product will first escape to the outside and is quickly detected. Disc parts can be arranged between the two housing parts to ensure a defined distance. The disc parts can be designed as washers and can be guided through the fastening screws or pushed onto them, for example.

[0035] Bearing units for supporting the drive shaft and the rotor shafts are preferably arranged in the transmission housing part. Preferably, two bearing units are arranged in the transmission housing part for at least one of the mentioned shafts. In particular, bearing units for supporting the rotor shafts are arranged only and exclusively in the transmission housing part.

[0036] Preferably, the two bearing units of a rotor shaft are arranged axially between the rotor unit (mounted or formed on the rotor shaft) and the rotor gear (mounted or formed on the rotor shaft). This enables a compact design and reliable support.

[0037] In particular, the housing and preferably the pump housing part comprises a cover which closes the pump chamber, wherein after dismantling the cover the rotor units are accessible in particular from the outside.

[0038] The rotary piston pump preferably comprises two rotor units, each with a plurality of two and preferably three rotor elements. This means that the rotary piston pump comprises a rotary piston pump and preferably a rotary piston pump.

[0039] In all embodiments, it is preferred that the rotor units are placed on the rotor shafts and are fastened there, in particular frontally, to the rotor shafts and preferably screwed on.

[0040] Advantageously, the drive motor is flanged to the housing and in particular to the gear housing part or to a clutch housing part connected to the housing or encompassed thereby.

[0041] According to the invention, the drive motor is connected to the housing via a connecting flange. According to the invention, the connecting flange has a U-shaped cross-section. The cross-section (in the longitudinal direction) can also have a U-, V-, W-, or H-shape. Such cross-sections are all essentially referred to here as U-shaped. What is essential here are two circumferential and spaced-apart flanges that are connected to one another in a central or centric region, for example, in a tubular manner. The axial distance between the flange parts is preferably smaller than the clear inner diameter of the tubular section. One of the flanges preferably forms the end of the gear housing, and the other flange is preferably connected to the front end of the motor housing or forms the front end flange of the motor housing. It is also possible and preferred for the connecting flange to have an essentially disc-shaped or ring-shaped shape.In particular, the connecting flange can be designed as a flat ring or disc. This allows for a particularly short design.

[0042] In particularly preferred embodiments, the connecting flange forms a closure between the housing and the motor housing. This enables a particularly compact, lightweight, yet stable design.

[0043] Preferably, an electrical control unit is included, which allows control of the conveying process. The control unit preferably comprises a frequency converter. In particular, the control unit also allows control and change of the conveying direction by operating the rotary piston pump in the opposite direction of rotation. In advantageous embodiments, the pump device comprises an electrical connection cable for the power supply, which can be provided in particular via a (standard) power connection of a house or industrial facility.

[0044] In all embodiments, it is preferred that the diameter of the drive motor be smaller than the height of the pump housing. Preferably, the drive motor is connected and / or flanged to the housing in a central height region.

[0045] In preferred embodiments, the length of the housing of the rotary piston pump is less than the length of the drive motor. Preferably, the length of the pump device is less than twice or, in particular, less than 1.5 times the length of the housing. This provides a compact pump device.

[0046] In preferred embodiments, the rotational axis of the drive pinion is arranged vertically offset from a center plane between the rotational axes of the rotor gears. This slight vertical offset ensures that only one of the rotor gears is driven by the drive pinion.

[0047] This ensures counter-rotation of the rotor units. The vertical offset is preferably less than 1 / 2, in particular less than 1 / 3, and preferably less than 1 / 4, and particularly preferably less than 1 / 5 or even 1 / 6 of the distance between the rotational axes of the rotor gears. This results in a particularly compact design.

[0048] The pump device preferably has at least one, and in particular two, foot units arranged symmetrically on the housing of the pump device. These foot units, in particular, have leg units or legs extending obliquely backward and downward toward the drive motor, supported on elongated feet. The length of the feet is greater than the length of the legs. This enables a stable structure. The design is low-vibration and vibration-damping.

[0049] The mobile transport vehicle according to the invention, such as a semi-trailer, tank trailer, tank semi-trailer, tank truck, or truck, comprises a storage tank and a pump device connected thereto, comprising a rotary piston pump and a drive motor. The rotary piston pump comprises a housing and two pump openings formed thereon, one of which serves as a pump inlet and the other as a pump outlet. At least two rotor units rotatably received in a pump chamber in the housing are provided to convey a fluid from the pump inlet to the pump outlet. The pump device is configured as previously described.

[0050] The two rotor units are mounted on rotatably mounted rotor shafts, each rotor shaft being equipped with a rotor gear located outside the pump chamber. Both rotor gears preferably have an identical number of teeth and are coupled to each other, in particular in opposite directions. A drive pinion of a drive shaft is coupled to one of the rotor gears. The drive pinion forms a reduction gear with the rotor gear, so that the rotor units rotate more slowly than the drive pinion. The drive shaft is arranged at a speed ratio of 1:1 coupled with a drive motor.

[0051] The vehicle according to the invention also has many advantages. The vehicle can have a lower overall weight and provide more space for loading and transport, since the rotary piston pump provided on the mobile vehicle is compact and has a low overall weight.

[0052] The drive motor of the rotary piston pump is preferably designed as an electric motor and can be connected to a stationary power supply, for example, in a household or industrial facility, via a connecting cable. However, it is also possible for a hydraulic motor to be provided as the drive motor and for the hydraulic motor to be controllably connected to a hydraulic circuit of the mobile vehicle.

[0053] In all embodiments, preferably at least the pump housing part, the rotor shafts and the respective rotor elements (and in particular the rotor units as a whole) are made of a steel and in particular a special steel and particularly preferably of a stainless steel.

[0054] Further advantages and features of the present invention will become apparent from the description of the embodiments which are explained below with reference to the accompanying figures.

[0055] The figures show: Figure 1 shows a mobile means of transport on a building in a highly schematic side view; Figure 2 shows a mobile pumping device, for example for the mobile means of transport from Figure 1 ; Figure 3 a schematic plan view of the mobile pump device according to Figure 2 ; Figure 4 shows a cross section A - A through the housing of the pump device 1 from Figure 3 ; Figure 5 a highly schematic cross-section through the rotary piston pump of the mobile pumping device according to Figure 2; Figure 6 shows a highly schematic cross-section through a mobile pump device according to the invention; Figure 7 shows a view of the front end of an embodiment of the motor shaft; Figure 8 shows a schematic cross-section through the motor shaft coupled to the drive shaft; Figure 9 shows a schematic exploded view of the drive shaft and the motor shaft; Figure 10 shows a highly schematic cross-section through a further mobile pump device according to the invention; and Figure 11 shows a highly schematic cross-section through a mobile pump device not according to the invention.

[0056] Figure 1shows a schematic side view of a mobile means of transport 100, which here is formed by a truck 102 and a tank trailer 101. On the tank trailer 101, which also represents a (separate) mobile means of transport 100, a storage tank 104 is formed, which is filled with a fluid to be filled, and in particular a liquid from, for example, the food sector.

[0057] The mobile means of transport 100 has wheels 103. In the rear area of ​​the tank trailer 101, a pumping device 1 is arranged below the rearwardly projecting bulge of the storage tank 104. Optionally, a mobile pumping device 1 can also be provided on the truck 102 as the towing vehicle, as indicated by the dashed arrow. A pumping device 1 can also be mounted longitudinally below the side member of the trailer, as shown between the towing vehicle and the rear wheels 103 of the semi-trailer 101 below the trailer frame. It is clearly evident that in this preferred mounting position, the overall length of the pumping device 1 and also the overall height are of crucial importance. A shorter and lower design is advantageous. A lower weight is also advantageous because it increases the potential payload.

[0058] The pumping device 1, located in the rear area, is connected to a power connection 201 of a building 200 via a connecting cable 38 and a plug 38a. The operating power for the pumping device 1 is thus drawn from the power grid of the building 200. This means that the engine of the truck 102 can remain switched off during, for example, the emptying or partial emptying of the storage tank 104. This reduces energy consumption and emits less noise.

[0059] At the same time, the hose 18 is connected to the pump outlet 5 of the pump device 1. The other end of the hose 18 is connected to the fluid connection 202 of the building 200.

[0060] To ensure reliable operation at a wide variety of locations and buildings 200, the drive motor 40 (see Figure 2) of the pump device 1 is generally used as a modified standard motor with an output of, for example, 7.5 kW, which can be operated on conventional three-phase or high-voltage power connections. Before installation, the drive motor 40 is adapted to the pump device 1.

[0061] The pump device 1 is controlled via the control unit 24, which includes a frequency converter 25 for regulating the speed of the drive motor and thus of the rotary piston pump.

[0062] Figure 2shows a pump device 1 used, for example, on the mobile means of transport 100 in a schematic perspective view. The pump device 1 comprises a housing 3 and an (electric) drive motor 40 connected thereto. The drive motor 40 is connected to the housing 3 via a connecting flange 30. It is also possible for the connecting flange 30 to simultaneously form the front end of the drive motor 40 and the rear end of the housing 3 and to be designed as a connecting flange (cf. Fig. 10 ).

[0063] The housing 3 comprises a pump housing part 8 and a gear housing part 9, in which the drive speed of the drive motor 40 is reduced and transmitted to the two rotor units 10 and 20 (see Figure 3) of the rotary piston pump 2. The pump housing part 8 and the gear housing part 9 each have an end wall or partition 23a and 23b, respectively, which are separated from one another by a gap 23c (freely accessible from the outside). In the event of leaks at the shaft feedthroughs, oil or product would leak from the pump housing part 8 or the gear housing part 9 into the gap 23c and thus outwards, and not into the other housing part.

[0064] On the pump housing part 8, the pump inlet and pump outlet are formed as pump openings 4 and 5. The entire pump device 1 is attached via a foot unit or bracket 15, for example, to the instrument panel or to the body of a mobile vehicle 100. The foot unit 15 has legs 15a and feet 15b (arranged symmetrically here), which also allow vibration damping.

[0065] Figure 3shows a plan view of the pump device 1 according to Figure 2 , where in the left part of Figure 3 The pump housing part 8 with the inlet 4 and the outlet 5 can be seen, to which the gear housing part 9 and the drive motor 40 are connected. The drive motor 40 is screwed to a connecting flange 30 and thus connected to the rotary piston pump 2.

[0066] In Figure 3 It can be seen that a center plane with the axis of rotation 39 of the drive motor 40 has a lateral distance 48 from a center plane 14 in which the axes of rotation of the rotor units of the rotary piston pump 2 are arranged.

[0067] At the front end of the pump device 1, a cover 28 closes the pump chamber 6 of the pump housing part 8. The pump device 1 enables a compact design. A length 17 of the housing 3, including the pump housing part 8 and the gear housing part 9, is less than a length 47 of the drive motor 40. This makes the total length 51 less than twice the length 47 of the drive motor 40.

[0068] Figure 4 shows a cross section A - A from Figure 3 , whereby only a small section of the drive motor 40 is shown. Figure 4 shows the internal structure in the pump housing part and the gear housing part 8 and 9.

[0069] The cut according to Figure 4runs through the rotor plane in which the mutually parallel rotor shafts 11 and 21 have their axes of rotation 19 and 29. In the area of ​​the drive motor 40, the section shown runs through the axis of rotation 39 of the drive motor 40. The axis of rotation 39 of the drive motor 40 is identical to the axis of rotation of the drive pinion 32 (compare Figure 6 ). The drive pinion 32 is shown in accordance with Figure 4 not visible because it is located in front of the cutting plane in the area of ​​housing 3.

[0070] The rotary piston pump 2 comprises two rotor shafts 11 and 21, each having axes of rotation 19 and 29. The center plane 42 lies exactly between the axes of rotation 19 and 29. The axes of rotation 19 and 29 are aligned parallel to one another. Rotor units 10 and 20, respectively, which generate the actual pumping action, are arranged on the rotor shafts 11 and 21 in the pump chamber 6 in the pump housing part 8. The rotor units 10 and 20 are fastened or screwed to the rotor shafts 11 and 21, respectively, via fastening means 44. The pump housing part 8 is separated from the gear housing part 9 by two partition walls 23a and 23b. The two rotor shafts 11 and 21 pass through the partition walls 23a and 23b. Seals 43 are provided on the passages to prevent the fluid to be filled from passing from the pump housing part into the gear housing part and to reliably prevent the reverse transfer into the fluid to be pumped.

[0071] The rotor shafts 11 and 21 are mounted axially spaced from one another via two (preferably conventional) bearing units 27 to ensure reliable operation. Furthermore, rotor gears 12 and 22, respectively, are rotatably mounted on the rotor shafts 11 and 21. The rotor gears 12 and 22 have an identical number of teeth and identical dimensions. The rotor gears 12 and 22 mesh with each other, so that a rotation of one of the rotor gears causes the other rotor gear to rotate in the opposite direction. This ensures that both rotor shafts, and thus both rotor units 10 and 20, rotate in opposite directions and synchronously during operation. The two bearing units 27 are arranged axially between the rotor gear 12 (or 22) and the rotating unit 10 (or 20).

[0072] If a drive motor 40 is to be replaced or must be replaced due to a defect, for example, the drive motor 40 is unscrewed from the connecting flange 30. A motor of the same or a similar make can be machined accordingly to form a corresponding recess 81 at the front end 41a of the motor shaft 41, which is suitable for coupling to the drive shaft 31.

[0073] A rotationally fixed connection between the motor shaft 41 of the drive motor 40 and the drive shaft 31 can be achieved by providing the recess 81 of the motor shaft 41 with a longitudinal groove 86 and by providing the drive shaft 31 with an axial groove 35. A coupling unit 71 in the form of a spring 36 or the like is inserted into both grooves, thereby achieving a rotationally fixed connection between the motor shaft 41 and the drive shaft 31.

[0074] In Figure 4A disk part 89 is shown enlarged, which is arranged between the pump housing part 8 and the gear housing part 9. In particular, several disk parts 89 are arranged on the connecting screws, distributed around the circumference. The disk parts 89 ensure a defined distance (23c) between the two housing parts 8 and 9.

[0075] Figure 5 shows a front view of a highly schematic cross-sectional view of the actual piston pump, showing the rotor units 10 and 20 with the three rotor elements 13 formed thereon. The three-armed rotor units 10, 20 are mounted on the rotor shafts 11, 21 in a rotationally fixed manner and rotate in opposite directions during operation, resulting in the flow direction for the fluid to be pumped from the pump inlet 4 to the pump outlet 5, as indicated by the arrows.

[0076] In Figure 5Additionally, the outer contours of the meshing rotor gears 12, 22 and the drive pinion 32 are shown in dashed lines. Here, for example, the drive pinion meshes with the rotor gear 22. A mirror-inverted arrangement is also possible. A design in which the drive pinion 32 meshes only with the rotor gear 12 is also possible. In any case, the drive pinion 32 meshes with only one of the rotor gears 12, 22.

[0077] In Figure 5 The rotational axes 19, 29 and 39 of the rotor gears 12, 22 and the drive pinion 32 are also shown. In the cross section according to Figure 5The three rotation axes 19, 29, and 39 form a triangle 60, here horizontally hatched, in which each rotation axis 19, 29, and 39 forms a vertex of the triangle 60. The rotation axis 19 is arranged at a distance 48 from the rotor plane 14. The rotor plane 14 is spanned by the parallel rotation axes 19 and 29. The rotational axis 39 of the drive pinion 32 is located in a perpendicular projection onto the rotor plane 14 between the rotational axes 19 and 29. The distance 49 to the center between the rotational axes 19 and 29 is relatively small and amounts to less than 1 / 3, and in particular less than 1 / 4 or 1 / 6 of the distance between the rotational axes 19 and 29. The distance 49 is greater than 0 and preferably greater than 1 / 40 or 1 / 20 of the distance between the rotational axes 19 and 29. In any case, it must be ensured that the drive pinion 32 only meshes with one rotor gear 12, 22. The drive pinion 32, together with the rotor gear 22, forms a reduction gear 7.

[0078] A triangle 60°, in which each interior angle is < 90°, results in a particularly compact design that requires only a small height and width (here viewed in the flow direction from inlet to outlet). The elimination of a separate reduction gear also saves a significant amount of length, thus providing a particularly compact pump device 1.

[0079] Figure 6 finally shows a highly schematic longitudinal section through a pump device 1 according to the invention, as it is in principle shown in the Figures 2 to 5 is shown. Figure 10 shows a slightly different design, but basically all functions are the same.

[0080] The rotor shafts 11, 21 are equipped with rotor units 10, 20 and rotor gears 12, 22. The two rotor gears 12, 22, as well as the bearing units 27, are located in the gear housing part 9 of the housing 3. The drive pinion 32 is coupled to one of the two rotor gears 12, 22, and here to the rotor gear 12. The drive pinion 32 meshes with the rotor gear 12. The rotor gear 12, in turn, meshes with the rotor gear 22. This causes the two rotor units 10, 20 to rotate in opposite directions and at the same speed when the drive pinion 32 rotates. The drive shaft 31 is rotatably mounted in the gear housing part 9 via bearing units (not shown). The drive shaft 31 is transferred from the gear housing part 9 into the motor housing 80. There, the drive shaft 31 is connected to the motor shaft 41 in a rotationally fixed manner.A rotationally fixed connection between the motor shaft 41 and the drive shaft 31 can be ensured via axial grooves and an inserted spring 36. Other connection options are also possible. The drive shaft 31 is accommodated in a recess 81 in the motor shaft 41. The motor shaft 41 can therefore have any desired outer circumference and outer cross-section. In particular, the outer circumference or outer surface can be defined by a cylinder that fits tightly against the outer surface.

[0081] By coupling the drive shaft inside the motor shaft 41, space and weight can be saved. Basically, a standard motor is used, in which the front end 41a of the motor shaft is drilled, milled, or hollowed out in some other way to form a defined recess 81. The recess 81 can basically be cylindrical. A milling cutter or other tool can form a longitudinal groove in the recess 81, thus enabling a rotationally fixed connection to the drive shaft 31. For the rotationally fixed connection, a coupling unit or spring 36 is inserted into the longitudinal groove 86 and the axial groove 35.

[0082] The Figure 6The variant shown has the advantage that drive motors equipped with it can also be replaced with other makes, provided the speed and power ranges, as well as the mechanical connections, are fundamentally compatible. The recess 81 can be installed on-site. This allows for rapid repairs even in remote areas and corners.

[0083] Because the rotational axis 39 of the drive shaft 31 is projected onto the rotor plane 14, which is spanned by the rotational axes 19 and 29 of the rotor shafts 11 and 21, and is located between the rotational axes 19 and 29, a particularly compact design of the pump device 1 according to the invention can be achieved. Figure 6 schematically shows, but also from the Figures 3 and 4As can be seen, the entire pump device 1 or the housing 3 of the pump device reaches a height 16 which is only slightly larger than the diameter 46 of the drive motor 40. In particular, the drive motor 40 with its housing and its cooling fins does not protrude upwards or downwards beyond the housing 3 of the pump device 1.

[0084] Figure 7 shows a schematic view of the front end 41a of the motor shaft 41, which allows a view into the interior of the recess 81. The recess 81 extends over a length of a coupling section 82. This is followed by a second section 83, which can extend, for example, partially and in particular completely inside the motor housing 80. The coupling section 82 can be as in Figure 6 also extend completely within the motor housing 80, but can also extend at least partially from there into the housing 3.

[0085] An example is Fig. 7 An internal toothing 88 is formed as a non-circular inner contour 87. During operation, the internal toothing 88 meshes with a closely fitting external toothing 75 of the drive shaft 31. The outer circumferential surface of the motor shaft 41 can be formed as a cylindrical circumferential surface 84.

[0086] Figure 8shows a schematic cross-section through the motor shaft 41 connected to the drive shaft 31. The dimensions are not to scale, but are shown purely schematically. For example, the tolerances are considerably smaller in reality. The motor shaft 41 surrounds the drive shaft 31, which is received in the recess 81. The recess is basically designed as a cylindrical cavity. However, the recess 81 also has (at least) one longitudinal groove 86 formed therein, which extends radially further outwards (but not all the way out here). The drive shaft 31 (or its rear end) is received in the essentially cylindrical recess 81. A radial extension as a coupling unit can be received with a precise fit in the longitudinal groove 86 in order to create a rotationally secure coupling.

[0087] Figure 9shows an exploded view of a variant in which a longitudinal groove 86 is formed on the recess 81, into which a spring 36 is introduced, which is also received in an axial groove 35 of the drive shaft 31 and enables a rotationally fixed coupling.

[0088] It is also possible for the drive shaft 31 and the motor shaft 41 to each include one (or more) cross-bores as coupling units 71, for example. A pin or the like can be passed through the aligned cross-bores as a coupling unit 72 (shown schematically in section in the motor shaft) and create a rotationally fixed coupling. The pin can also be screwed in, glued in, or clamped.

[0089] Figure 10 shows a modification of the design of the Figures 2 to 4, wherein a connecting flange 26 is inserted, which forms the rear end cover of the housing 3 and (simultaneously) also the front end cover of the motor housing 80.

[0090] The connecting flange 26 comprises, in particular, two parallel and spaced-apart circumferential flanges that form an outwardly open, circumferential "U." The space remaining between the walls of the "U" allows for easy assembly and disassembly.

[0091] Figure 11 shows a non-inventive modification of the design of the Figures 2 to 4, wherein a particularly short connecting flange 26 is used, which forms the rear end cover of the housing 9 and (simultaneously) also the front end cover of the motor housing 80. In very simple embodiments, the connecting flange 26 can be designed as a disc-shaped ring. In any case, a circumferential flange is formed, on which the gear housing part 9 is arranged on one side and the drive motor 40 on the other side. The drive motor 40 and the gear housing part 9 are preferably each connected to the flange 26. Both can also be connected to one another via common connecting elements, clamping the flange 26 between them. In this embodiment, the flange 26 forms the end of the gear housing part 9 and also the end of the housing of the drive motor 40.

[0092] The designs according to Figures 10 and 11Apart from the design of the flange 26, they can each have all the features of the previous embodiments, so that in the Figures 10 and 11 Not every single reference symbol is shown and will not be described. In this regard, reference is made to the previous explanations in the general description and the description of the other embodiments.

[0093] The execution according to Fig. 10 can allow a shorter overall length than the previously described designs, since the motor can be made shorter.

[0094] The execution according to Fig. 11 allows for an even shorter design than all others, since the connecting flange 26 is practically designed as a thin, plate-like flange and simultaneously forms the front end of the motor housing. Accordingly, assembly can be carried out sequentially.

[0095] The drive pinion 32 is preferably a separate component from the motor shaft 41. The drive pinion 32 or its shaft portion can be pressed onto the motor shaft 41. Another non-positive or positive connection between the drive pinion 32 (or the shaft portion of the drive pinion 32) and the motor shaft 41 is also possible.

[0096] In all embodiments, the drive pinion 32 can be directly machined into or formed on the motor shaft 41. The drive pinion 32 can also be formed integrally with the motor shaft 41.

[0097] The terminal box 53 of the drive motor 40 is, in contrast to the illustration, Figure 2 preferably arranged turned forwards or backwards (parallel to the connecting line between inlet and outlet) so that it does not protrude upwards (or downwards) and thus takes up very little installation space.

[0098] Also in the lateral direction, as Figure 3shows, a very compact design is achieved. The compact design in height and in the lateral direction is achieved by arranging the rotational axes 19 and 29 of the rotor shafts 11 and 21 in a common rotor plane 14, while the rotational axis 39 of the drive shaft 31 is provided laterally spaced therefrom, so that in a view transverse to the representation of Figure 4 a triangle is formed by the rotational axes 19, 29 and 39, which has no obtuse angle and thus provides a particularly compact rotary piston pump.

[0099] By eliminating the need for a separate reduction gear stage, installation space is saved and the overall weight is significantly reduced. The weight savings are noticeably increased by the fact that the drive shaft 31 is accommodated in the recess 81 of the motor shaft 41. The outer circumference of the motor shaft 41 does not need to be enlarged; rather, the recess 81 can be machined into a standardized motor shaft with a cylindrical outer circumference. Diameter enlargements are not necessary, as is the case when the motor shaft is inserted into a coupling.

[0100] Overall, the invention provides an advantageous pumping device with a rotary piston pump and an advantageous mobile vehicle with a pumping device. Both the installation space and the weight can be reduced without compromising reliability. List of reference symbols:

[0101] 1 Pump device 38 Connection cable 2 Rotary piston pump 38a Plug 3 Housing 39 Rotation axis of 32 4 Pump opening, inlet 40 drive motor 5 Pump opening, outlet 41 Motor shaft 6 Pump room 41a front end 7 Reduction gear 42 Middle level between 19 and 29 8 Pump housing part 43 Seal of 11, 21 9 Gearbox housing part 44 Fixing of 10.20 10 Rotor unit 46 diameter 11 rotor shaft 47 length 12 rotor gear 48 lateral distance 13 Rotor element 49 Height offset 14 Rotor plane 51 length 15 bracket 52 screw 15a leg 53 terminal box 15b Foot 60 triangle 16 Height of 3 71, 72 Coupling units 17 Length of 3 75 external gearing 18 Hose 80 Engine housing 19 Rotation axis of 12 81 recess 20 Rotor unit 82 Coupling section 21 rotor shaft 83 Interior section 22 rotor gear 84 circumferential area 23a partition 85 cylindrical cavity 23b partition 86 Longitudinal groove 23c gap 87 non-circular inner contour 24 Control unit 88 Internal gearing 25 Frequency converter 89 disc 26 connecting flange 100 mobile means of transport 27 storage unit 101 tank trailer 28 Cover wall, lid 102 trucks 29 Rotation axis of 22 103 Wheels 30 connecting flange 104 storage tank 31 drive shaft 200 Building 32 drive pinion 201 Power connection 35 axial groove 202 Fluid connection 36 Coupling unit, spring

Claims

1. A mobile pump device (1), in particular for use on mobile transport means (100), such as semitrailers, tank trailers, tank semitrailers (101), tankers and lorries (102), with a drive motor (40) and with a rotary piston pump (2), wherein the drive motor (40) comprises a motor shaft (41) for driving the rotary piston pump (2) and a motor housing (80), wherein the rotary piston pump (2) comprises a housing (3) with a pump housing part (8) and a gear housing part (9), wherein two openings (4, 5) are formed on the pump housing part (8), one of which serves as a pump inlet (4) and the other as a pump outlet (5), and wherein the rotary piston pump (2) comprises at least two rotor units (10, 20) disposed rotatably in a pump chamber (6) in the pump housing part (8), in order to convey a fluid from the pump inlet (4) to the pump outlet (5), wherein the two rotor units (10, 20) are disposed on rotatably mounted rotor shafts (11, 21), wherein each rotor shaft (11, 21) is equipped with a rotor gear (12, 22) arranged outside the pump chamber (6), wherein a drive pinion (32) of a drive shaft (31) of the rotary piston pump (2) is coupled with one of the rotor gears (12), wherein the rotor gears (12, 22) and the drive pinion (32) are accommodated in the gear housing part (9), characterised in that the motor shaft (41) of the drive motor (40) comprises a cutout (81) at the front end (41a), in which the drive shaft (31) of the rotary piston pump (2) is received and coupled with the drive shaft (31), and that the drive motor (40) is connected via a connection flange (26) with a U-shaped cross-section to the housing (3), wherein the connection flange (26) forms the rear closure cover of the housing (3) and at the same time the front closure cover of the motor housing (80), wherein the connection flange (26) comprises two flanges running in parallel and spaced apart from one another, which form a surrounding "U" opened outwards.

2. The mobile pump device (1) according to claim 1, wherein the motor shaft (41) comprises a coupling section (82) at the front end (41a) of the motor shaft (41), at which the cutout (81) is formed.

3. The mobile pump device (1) according to the preceding claim, wherein the coupling section (82) of the motor shaft (41) is bounded by a cylindrical circumferential surface (84), which abuts against the motor shaft (41).

4. The mobile pump device (1) according to any one of the preceding claims, wherein the cutout (81) forms an essentially cylindrical hollow space (85) and wherein the cutout (81) in particular comprises at least one longitudinal groove (86).

5. The mobile pump device (1) according to any one of the preceding claims, wherein the cutout (81) has a non-round inner contour (87).

6. The mobile pump device (1) according to any one of the preceding claims, wherein an inner toothing system (88) is formed on the cutout (81) and wherein an outer toothing system (75) interacting with the inner toothing system (88) of the cutout (81) is formed in particular on the drive shaft (31).

7. The mobile pump device (1) according to any one of the preceding claims, wherein at least one coupling unit (72) is included, which interacts with at least one coupling unit (71) on the drive shaft (31) and / or the motor shaft (41), and wherein at least one extending transverse opening (71) is formed in particular in the drive shaft (31) and / or the motor shaft (41), at which a rotationally fixed coupling of the drive shaft (31) and the motor shaft (41) is achieved via a coupling unit (72) arranged therein.

8. The mobile pump device (1) according to any one of the preceding claims, wherein the drive motor (40) is designed as an electric motor and can be driven by three-phase alternating current and has a power range between 1 kW and 15 kW, in particular between 5 kW and 10 kW.

9. The mobile pump device (1) according to any one of the preceding claims, wherein the pump housing part (8) and the gear housing part (9) are separated from one another by two separate partition walls (23a, 23b) and a gap (23c) and wherein bearing units (37, 27) for bearing the drive shaft (31) and the rotor shafts (11, 21) are arranged in the gear housing part (9) and wherein at least one disc part (89) is arranged in particular between the separate partition walls (23a, 23b).

10. The mobile pump device (1) according to any one of the preceding claims, wherein the housing (3) comprises a cover (28) which closes the pump chamber (6) and wherein the rotor units (10, 20) are accessible after dismantling of the cover (28), and / or wherein the rotary piston pump (2) comprises two rotor units (10, 20) each with a plurality of two, preferably three rotor elements (13), wherein in particular the rotor units (10, 20) are pushed onto the rotor shafts (11, 21) and fastened in particular at the front end to the rotor shafts (11, 21).

11. The mobile pump device (1) according to any one of the preceding claims, wherein the two bearing units of a rotor shaft are arranged axially between the rotor unit and the rotor gear.

12. Mobile transport means (100), such as semitrailers, tank trailers, tank semitrailers (101), tankers and lorries (102), with a storage tank (104) and a mobile pump device (1) connected thereto according to any one of the preceding claims.

13. The transport means (100) according to the preceding claim, wherein the drive motor (40) of the rotary piston pump (10) is designed as an electric motor and can be connected via a connecting cable (38) to a stationary power supply.