WO2022238034A1

WO2022238034A1 - Pump for conveying a medium and method for monitoring

Info

Publication number: WO2022238034A1
Application number: PCT/EP2022/057405
Authority: WO
Inventors: Sascha Plazar; Johannes Schulz
Original assignee: Seepex Gmbh
Priority date: 2021-05-12
Filing date: 2022-03-22
Publication date: 2022-11-17
Also published as: DE102021112422A1; EP4337862A1

Abstract

The invention relates to a pump for conveying a medium, more particularly a liquid or a solid-liquid mixture, comprising at least one drive (6), a first shaft (W1) and a second shaft (W2), which is rotationally driven by the first shaft (W1) and is connected to a pump element (2) or is part of a pump element, wherein the first shaft (W1) is connected to the second shaft (W2) by means of at least one connection (V), and wherein during operation the first shaft (W1) rotates with a first angle of rotation and the second shaft (W2) rotates with a second angle of rotation, each in relation to a common zero angle. The invention is characterized by a monitoring device (13), which is designed to monitor the state of the connection (V) by determining a phase shift, occurring at the connection (V), between the first angle of rotation and the second angle of rotation.

Description

1

Pump for conveying a medium and monitoring method

Description:

The invention relates to a pump for conveying a (fluid) medium, in particular a liquid or a solid-liquid mixture or a liquid-gas mixture, with at least one drive, a first shaft and a second shaft driven in rotation by the first shaft, which is connected to a pump element or is part of a pump element, the first shaft being connected to the second shaft by means of at least one connection (or coupling), wherein during operation the first shaft rotates at a first angle of rotation and the second shaft rotates at a second angle of rotation, each based on a common zero angle rotate.

The pump is preferably a displacement pump, in particular an eccentric screw pump, which has at least one stator (eg made of an elastic material) and a rotor rotating in the stator as the pump element. In such an eccentric screw pump, the rotor z. B. be connected to the drive via at least one coupling rod, which is also referred to as a cardan shaft, ie a drive shaft or a connecting shaft connected to the drive, which forms the first shaft, is connected to the rotor in an articulated manner via the coupling rod or a comparable element , so that the second shaft is part of this rotor, e.g. B. as a rotor head. The coupling rod is consequently connected to a first (drive-side) joint with the first shaft (second connecting shaft/drive shaft) and a second (rotor-side) joint to the second shaft, e.g. B. connected to the rotor head of the rotor. The coupling rod enables eccentric 2 Irish movement of the rotor or the rotor head of such an eccentric screw pump. The pump has a z. B. on the suction side of the stator is closed pump housing, z. B. suction housing, which usually has a housing opening, z. B. has an inlet opening for the medium to be pumped. Furthermore, the pump has a z. B. pump housing connected on the pressure side, e.g. B. a pressure port and / or a pressure-side line. Such an eccentric screw pump is a pump from the group of rotating displacement pumps that are used to convey a wide variety of media and in particular high-viscosity liquid speeds in different industrial sectors. The media to be funded can e.g. B. also contain solids. As an alternative to a progressive cavity pump, the pump may be another type of positive displacement rotating shaft(s) pump.

Eccentric screw pumps of the type described are z. B. known from DE 102014 112 552 A1, DE 10 2010 037 440 A1, WO 2009/024279 A1 or DE 102018 113347 A1.

Basically, there is a need to monitor the condition and/or operation of pumps, e.g. B. progressing cavity pumps to monitor. The main focus was on monitoring the wear of the stator, which is made of elastic material and is subject to wear.

DE 20 2005 008 989 U1, for example, describes an eccentric screw pump in which a sensor is assigned to the stator, with which compressions and/or movements of the stator or of the elastic material are measured during the rotation of the rotor. 3

DE 10 2018 113 347 A1 describes a method for determining or monitoring the status of an eccentric screw pump, in which the time profile of an operating parameter of the pump is made available, which periodically pulsates at the pump frequency or a multiple of the pump frequency and its pulsation amplitude depends on the condition of the progressing cavity pump. In particular, the pulsation amplitude of the pressure pulsation is determined and the state of the eccentric screw pump, in particular of the stator, is determined by comparison with one or more comparative values.

However, there is also a need to determine or monitor wear or damage to other components of an eccentric screw pump. This applies, among other things, to the connections within the rotating unit, e.g. B. for the articulated connections of the coupling rod. - This is where the invention comes in.

The invention has for its object to provide a pump with simple means reliable monitoring of the condition, z. B. the wear condition of connections within the rotating unit. A reliable monitoring of the wear of articulated joints within the rotating unit of an eccentric screw pump should preferably be made possible.

To solve this problem, the invention teaches that a monitoring device is provided or the pump is equipped with a monitoring device for a generic pump of the type described above, which is set up to monitor the state of the connection by detecting a phase shift occurring in the connection is determined between the first angle of rotation and the second angle of rotation. Preferred is the 4

Monitoring device set up to monitor the state of wear of the connec tion between the first shaft and second shaft by a phase shift occurring in the connection due to wear between the first angle of rotation and the second angle of rotation is determined. Alternatively, however, there is also the possibility of monitoring other damage or defects that exist or occur independently of wear and tear in the area of the connection. The connection to be monitored may be a separable (i.e. dismountable) and/or articulated connection, e.g. B. a joint or a separable connection on the rotor head. This also includes pluggable and/or bendable or flexible connections, e.g. B. the connection via a stub shaft or a flexible coupling rod. The first shaft is preferably a centrically or circularly rotating shaft that rotates about a fixed axis. The second shaft can likewise be such a centrally rotating shaft. However, the second shaft can also rotate eccentrically with respect to the first shaft.

Preferably, not only can wear and tear be monitored or damage detected, but predictions can also be made in the sense of predictive maintenance (“Condition Monitoring7“Predictive Maintenance”). This will be discussed further below.

The invention is particularly preferably implemented in an eccentric screw pump in which a rotating rotor is provided as the pump element, which rotates inside a stator (eg made of elastic material). In this progressing cavity pump, a coupling rod can be provided within the rotating unit, which is arranged between the first shaft (e.g. connecting shaft or drive shaft) and the rotor or rotor head (as the second shaft), the coupling rod controlling the eccentricity between the first 5

Wave and the second shaft (z. B. rotor head) ensures or allows and the coupling rod z. B. with a first (drive-side) joint with the first shaft (z. B. connecting shaft / drive shaft) and with a second (rotor-side) joint with the second shaft (z. B. the rotor head) is connected ver. In such an embodiment, the monitoring device is set up to monitor the condition (e.g. state of wear) of the first joint and/or the second joint by a (e.g. due to wear) occurring in one joint or in both joints Phase shift between the first angle of rotation and the second angle of rotation is determined.

The invention is based on the knowledge that the connections or couplings within the rotating unit, z. B. the joints, are subject to wear or damage and that such wear or damage can be detected by monitoring or analyzing a phase shift between the first shaft (e.g. drive shaft) and the second shaft (e.g. the rotor head) can be determined. Because damage or wear within a joint can lead to the rotor "running after" in relation to the drive shaft, i. H. due to the torque acting on the rotor, there is wear dependent on the direction of rotation, which leads to a phase shift between the rotation of the drive shaft and the rotor. This phase shift can be determined and monitored according to the invention.

This is particularly true for embodiments where one or more joints allow free movement in multiple directions. It can be z. B. be pin joints, ball joints, cardan joints, universal joints or the like. A bolt joint has on the one hand an insertion receptacle and on the other hand one in the insertion receptacle 6 engaging pins and a connecting pin fixing the pin in the insertion receptacle. During operation, the joint bolts can work their way through the rotor head or the plug-in socket/coupling rod bushing due to wear, or they can be worn down themselves. When the bolt is worked into the coupling rod or the rotor head, or if the bolt wears heavily, the rotor “runs after” in relation to the drive shaft, as already mentioned, and thus to the phase shift observed according to the invention. By determining or monitoring this phase shift, the status of the rotating unit and in particular the status of the connections, e.g. B. joints close. This means that maintenance/repairs can be carried out in good time and joint failure can be avoided. Predictions can preferably be made so that timely maintenance or repairs can be carried out. In this way, maintenance work can be excellently planned and optimized and, in particular, measures can be taken in good time to avoid damage.

The advantages mentioned can be achieved not only with progressing cavity pumps with a coupling rod and several (pin) joints, but also with other embodiments of progressing cavity pumps, e.g. B. in embodiments with only one joint or in embodiments with a flexible coupling rod without (dismantling) joints. Moreover, the advantages can be obtained not only in progressive cavity pumps, but also in other types of positive displacement pumps with rotating shafts and in particular connections between rotating shafts.

In practice, the joints of the eccentric screw pump z. B. by suitable means, e.g. B. cuffs, separated from the medium to be pumped. If such a cuff is damaged, it can 7

Medium penetrates into the area of the joint and leads to increased wear. Especially in such cases, damage and consequential damage can be avoided by the monitoring according to the invention.

Of particular interest is the fact that the joint wear can be easily determined/monitored and optionally also predicted without dismantling the pump or the relevant components.

In a preferred embodiment, the monitoring device for monitoring the state of the pump has one or more sensors that generate one or more signals that depend on the first angle of rotation and/or the second angle of rotation and/or the phase shift. The monitoring device can have an evaluation unit with which, in particular, the signals from the sensors are processed and evaluated. The sensors can be z. B. be position sensors. Such position sensors are z. B. inductive, capacitive, magnetic or optical sensors. In this preferred embodiment, the phase shift is thus measured directly via the sensors. So there is z. B. the possibility of providing a first sensor in the area of the first shaft (e.g. drive shaft/stub shaft) and a second sensor in the area of the second shaft (e.g. rotor/rotor head), so that the phase shift between the two angles of rotation can be determined directly from the signals of the two sensors (e.g. distance sensors). As sensors z. B. (stationary) Flall sensors are used, in which case z. B. a magnet is attached.

The time interval at which a defined measuring point is detected on both sensors per revolution is provided as the starting point/zero angle when the pump is new or when it is commissioned. With increasing 8th

Wear increases or decreases the time interval between the two detection times at the same speed. If the time difference of the detections is related to the length of a period (revolution), the phase shift between the two signals can be calculated directly. This phase shift serves as a measure of the wear of the joint or joints.

Incidentally, the determination of a phase shift between two angles of rotation does not necessarily mean an absolute determination of a value for the phase shift, but it may be sufficient to determine the time intervals and evaluate them directly. In this case, the time intervals or time differences represent the phase shift, so that the respective status of the connection can be inferred from the time differences. As a rule, however, it is expedient to also take into account the speed of the respective shaft, which can vary during operation, so that the time intervals, taking into account the respective speed, are included in the determination of the phase shift.

Even if an eccentric screw pump often has a coupling rod with two connecting joints or jointed connections between the drive shaft and rotor, it can be sufficient to work with a first sensor in the area of the first shaft and a second sensor in the area of the second shaft (rotor). so that the "total wear" of the two joints is determined via the phase shift.

In a possible development, a further (third) sensor can be provided, e.g. B. in the area of the coupling rod, so that on the one hand a first phase shift between the drive shaft and the coupling rod and on the other hand a second phase shift between the coupling rod and the 9

Rotor can be determined. In this way, the wear of the two joints can be determined/monitored selectively and separately. In principle, two detection points, e.g. B. two sensors are sufficient. There is the option of using several detection points or sensors for several connections. In the case of N connections (e.g. couplings or joints), there are then N+1 detection points, e.g. B. sensors are used.

In a modified embodiment, a single sensor can also be sufficient for monitoring a connection between the first and second shaft, which is arranged directly in the area of the connection and measures a variable from which the phase shift can be determined.

The invention is preferably implemented in the embodiment described with a coupling rod which is connected on both sides with joints to the drive shaft/stub shaft on the one hand and the rotor on the other. However, the invention can be realized in the same way with progressive cavity pumps, in which work is only carried out with a single joint or with non-articulated connections, e.g. B. in eccentric screw pumps with a flexible shaft or flexible components within the rotating unit.

Alternatively or additionally, the principle according to the invention can also be used in the area of the drive of the eccentric screw pump, e.g. B. realize in the connection between a drive shaft and a stub shaft. So e.g. B. the (electric) drive of an eccentric screw pump can be equipped with an integrated drive shaft, which is connected via a connection to another shaft, which is referred to as a connecting shaft or as a stub shaft. The stub shaft can optionally turn with a 10

Coupling rod or other element to compensate for the eccentricity of the rotor may be connected. In the event of wear or damage, a phase shift can also occur between the drive shaft and stub shaft. B. sensors are arranged in the area of the drive shaft and/or the stub shaft.

As already described, the monitoring device can be provided or connected to an evaluation unit which, for. B. processes and evaluates the signals from the sensors. Furthermore, a threshold value for the phase shift can be stored in the evaluation unit, so that z. B. a message is generated during operation when the threshold value is reached or exceeded, e.g. B. an optical and / or acoustic alarm signal. Alternatively, however, it is also possible to work without a fixed threshold value. It is therefore possible to store one or more comparison values in the evaluation unit, e.g. B. during the operation of a new pump or new connection. In the course of operation, the development of the phase shift over time can then be monitored and in this way the status of the connection can be deduced.

There is preferably the possibility of continuously determining the state of the pump and using the determined state data to make a prediction about the state and/or the time of maintenance appointments using an algorithm. An algorithm is stored in the evaluation unit, with which predictions of a possible need for maintenance can be made from the data. The evaluation unit can consequently be designed for a further analysis step, namely a prediction, so that predictive servicing and maintenance is made possible. 11

Optionally, the evaluation unit can also be set up to analyze the phase shift (ie the difference in the angles of rotation) taking into account the rotational speed of the first shaft and/or the second shaft. In particular, there is the possibility that the phase shift is speed-dependent or behaves differently at different speeds of the rotor. In this respect, it can be expedient to take the speed into account when evaluating the phase shift. This is usually possible without further ado, since the rotational speed can be recorded in any case via the measuring devices provided and is usually included in the determination of the phase shift anyway, in that the time difference of the respective signals is set in relation to the length of the period (rotation), to determine the phase shift between the signals. In addition, the phase shift as a function of this speed can then also be considered during the evaluation. The speed is determined by the time difference between the signals. Alternatively or additionally, there is the possibility of determining the phase shift taking into account the torque and/or the axial force (of the shafts or the respective shaft). This possibility is of particular interest when a joint or a coupling rod made of a material other than metal, e.g. B. is used from an elastomer, ie in materials that are elastically deformable, since then the angle of rotation could change with the speed or the pressure. It is then expedient to also record and take into account the torque, because in the case of elastically deformable components, the torque would usually be responsible for the phase shift, so that the torque can be used to compensate for the corresponding deformations in the evaluation. The axial force can also be relevant, which influences how strongly a part can work its way into a material not only in the radial direction but also in the axial direction. In such a case, it could be due to changing printing conditions 12

The direction of the axial force reverses on the suction and pressure sides, i. H. the rotor is pushed or pulled in the opposite direction and the phase angle returns to its original position. In this case, there may be incorporation or wear in the other direction, so that the evaluation of the axial force can optionally be advantageous. The preferred option of determining the phase shift as a function of a rotational speed and/or a pressure can be implemented not only with joints, but also with connections of a different type.

Overall, the invention enables a simple and proper monitoring of the condition of connections within the rotating unit of a pump, z. B. the condition of the joints of a progressive cavity pump. Above all, this allows the onset of wear to be detected in good time, e.g. B. in pin joints in which the pin is incorporated into the other joint part or is itself subject to wear. The detection can be implemented with inexpensive standard sensors. When using a sensor with a switching output, the signals can be evaluated via existing industrial circuits. At the same time, the speed of the pump can be determined from the signals. This means that no additional sensors are required if the phase shift and the speed are monitored at the same time.

The monitoring device or the evaluation unit is particularly preferably designed in such a way that not only current status data, e.g. B. a certain wear or damage can be detected, but it is also possible in particular to make predictions about the condition of the pump or a connection and/or predictions about the timing of maintenance measures. The evaluation unit is therefore with a 13

Algorithm equipped with which predictions about the maintenance requirement can be made from the continuously determined data. For this purpose, optional display devices can be provided on the pump, with which certain states are displayed acoustically and/or optically. The monitoring device is particularly preferably equipped with an interface for data transmission or data query or an interface so that data and/or predictions can be made available, e.g. B. via computer and/or end devices (e.g. smartphone, tablet or the like). In this way, information can also be obtained at greater distances from the pump, e.g. B. receiving end devices and, if necessary, visualizing them. So can z. For example, maintenance technicians can quickly and easily transmit current information on the condition of individual pumps or individual components and plan maintenance work. According to the invention, condition monitoring as well as predictive maintenance can consequently be implemented. Production and pump data can be collected centrally and, if necessary, accessed via any end device. In this way, production can be easily monitored and systematically optimized.

Consequently, not only damage or other conditions can be predicted with the aid of the monitoring device, but warning messages can also be generated. Based on the maintenance forecasts, maintenance intervals can be planned in an optimized manner, thus minimizing maintenance costs. There is also the option of carrying out maintenance not on an interval basis but dynamically as required. Such flexible servicing and maintenance also reduces downtimes and thus enables efficient production for the pump operator. In addition, optimized maintenance based on the determined status data leads to a 14

Extension of the service life of the pump and/or an increase in efficiency and thus an increase in efficiency.

The monitoring device and the evaluation unit can be part of the pump or can be arranged directly on the pump. Alternatively, the monitoring device or parts of the monitoring device and/or the evaluation unit can also be spatially separated from the pump and z. B. in a (central) controller or a (central) computer. In particular, there is the possibility that only the necessary data is recorded in the monitoring device of the pump and, if necessary, temporarily stored. The data can be sent via the interface mentioned, e.g. B. be transmitted wirelessly or wired to a computer and / or a terminal, so that the algorithm mentioned for evaluating z. B. can work on a computer and / or a terminal.

The subject matter of the invention is not only the pump described, but also a method for monitoring the operation and wear of such a pump. During operation, the first shaft rotates at a first angle of rotation and the second shaft rotates at the second angle of rotation, each based on a common zero angle. According to the invention, the state of the connection or connections is/are monitored by determining or monitoring a phase shift occurring in the connection between the first angle of rotation and the second angle of rotation. In a preferred development of the method according to the invention, the measures described in connection with the pump are protected individually and in combination. 15

The invention is explained in more detail below with reference to drawings which merely represent an exemplary embodiment. Show it

1 shows an eccentric screw pump with a monitoring device for monitoring the condition, for example the wear condition, in a simplified side view,

FIG. 2 shows an enlarged detail from FIG. 1 in the area of a joint,

Fig. 3A, 3B each a cross section in the region of the joint in under different states of wear and

4A, 4B measurement signals for the joint according to FIGS. 3A and 3B,

FIG. 5 shows a view from FIG. 1 in the area of the drive shaft.

1 shows an eccentric screw pump which has a stator 1 made of an elastic material and a rotor 2 rotating in the stator 1 , the stator 1 being surrounded by a stator casing 3 . The pump also has a suction housing 4 and a connecting piece 5 , which is also referred to as a pressure piece 5 . The pump also has a pump drive 6 which works on the rotor 2 via a coupling rod 7 . The coupling rod 7 is connected to the drive shaft via a coupling joint 8 on the drive side and to the rotor 2 or the rotor head via a coupling joint 9 on the rotor side.

In this exemplary embodiment, the coupling joints 8, 9 are each designed as bolt joints, each of which has an insertion receptacle 10 16 and on the other hand a pin 11 engaging in the insertion receptacle 10 and a connec- tion bolt 12 fixing the pin 11 in the insertion receptacle 10 (see FIG. 2).

A drive shaft or connecting shaft 18 driven by the drive forms a first shaft W1 and the rotor 2 or rotor head forms a second shaft W2, the first shaft W1 being connected via the connecting joints 8, 9 as connections V to the second shaft W2. During operation, the first shaft W1 (drive shaft) rotates at a first angle of rotation and the second shaft W2 (rotor head) rotates at a second angle of rotation, each based on a common zero angle. When new, the phase shift between the first angle of rotation and the second angle of rotation is zero or such a phase shift can be defined as a zero angle. With a monitoring device 13 provided according to the invention, a z. B. is determined and monitored by wear Occurring phase shift between the first angle of rotation and the second angle of rotation. For this purpose, the two sensors 15, 16, which are only indicated, can be provided in the exemplary embodiment shown, namely on the one hand in the area of the first shaft W1 and on the other hand in the area of the second shaft W2. With the help of these sensors 15, 16 z. B. can be designed as distance sensors, the phase shift can be determined directly. In this regard, reference is also made to FIGS. 3A and 3B and FIGS. 4A and 4B. 3A and 4A each show a new state and FIGS. 3B and 4B each show a state of wear of a connection V according to the invention, e.g. B. a pin joint 8, 9.

The two sensors 15, 16 each generate switching signals which, according to FIG. 4A, have only a very short time interval D T1 . This time interval D T1 can be the starting point of the monitoring 17

Form new condition, d. H. such a phase shift can be stored in an evaluation unit 14 as a reference value or comparison value.

In contrast, FIG. 4B shows the course of the signals with increasing wear, in that the time interval D T2 between the two detections increases. By relating the time difference of these signals to the length of a period (revolution), the phase shift between the two signals can be determined, so that the phase shift can be used as a measure of the wear on the joint. This monitoring is carried out with the monitoring device 13, which includes in particular the sensors 15, 16 and the evaluation unit 14.

Incidentally, is shown in Fig. 5 in a detail from Fig. 1 that with such an eccentric screw pump integrated into the drive 6 drive shaft 17 does not have to be directly connected to the drive-side coupling joint 8, but in this embodiment the Drive 6 integrated drive shaft 17 connected to a connecting shaft 18, which is also referred to as a stub shaft or is designed as a stub shaft in this embodiment. In the exemplary embodiment, this stub shaft 18 is connected as the first shaft W1 via the coupling joints 8, 9 and the coupling rod 7 to the rotor 2 or rotor head as the second shaft W2. In Fig. 1 and 5 are also an example of a connection housing 19 and a shaft seal device 20, z. B. Mechanical seal in the area between the drive 6 and housing 4 indicated.

Furthermore, there is also the possibility of realizing the principle according to the invention in the area of the connection between the drive shaft 17 and the stub shaft 18 . In this case, the drive shaft 17 would be the first shaft and the 18

Plug-in shaft 18 the second shaft so that the condition of the connection between these two shafts can be monitored. Details are not shown in the figures.

Claims

19 patent claims:

1. Pump for conveying a medium, in particular a liquid or a solid-liquid mixture, with at least one drive (6), a first shaft (W1) and a second shaft (W2) driven in rotation by the first shaft (W1), which is connected to a pump element (2) or is part of a pump element (2), the first shaft (W1) being connected to the second shaft (W2) by means of at least one connection (V), the first shaft ( W1) rotate at a first angle of rotation and the second shaft (W2) rotate at a second angle of rotation, each related to a common zero angle, characterized by a monitoring device (13) which is set up to monitor the state of the connection (V), by determining a phase shift occurring in the connection between the first angle of rotation and the second angle of rotation.

2. Pump according to claim 1, characterized in that the connection (V) is designed as a separable and / or articulated connection, z. B. as a joint or coupling joint (8, 9).

3. Pump according to claim 1 or 2, characterized in that the monitoring device (13) is set up to monitor the state of wear of the connection (V) or of the connections by a phase shift occurring due to wear in the connection (V). is determined between the first angle of rotation and the second angle of rotation. 20

4. Pump according to one of claims 1 to 3 in the embodiment as an eccentric screw pump, with at least one stator (1) and a rotor rotating in the stator (2) as the pump element.

5. Pump according to claim 4, with a coupling rod (7) between the first shaft (W1) and the rotor (2) as the second shaft (W2), wherein the coupling rod (7) with a first (drive-side) joint (8) is connected to the first shaft (W1) (e.g. connecting shaft/drive shaft) and to the rotor (2) by a second joint (9) on the rotor side.

6. Pump according to claim 5, characterized in that the monitoring device (13) is set up to monitor the state of wear of the first joint (8) and/or the second joint (9) by a wear in a joint ( 8, 9) or in both joints (8, 9) occurring phase shift between the first angle of rotation and the second angle of rotation is determined.

7. Pump according to one of Claims 1 to 6, characterized in that the joint (8, 9) or the joints (8, 9) is/are designed as a pin joint or pin joints, the pin joint having on the one hand an insertion receptacle (10) and on the other hand a pin (11) engaging in the insertion receptacle (10) and a connecting bolt (12) fixing the pin (11) in the insertion receptacle (10).

8. Pump according to one of claims 1 to 7, characterized in that the monitoring device (13) has one or more sensors (15, 16) which generate one or more signals from the first angle of rotation and / or depend on the second angle of rotation and/or the phase shift. 21

9. Pump according to one of Claims 1 to 8, characterized in that the monitoring device (13) has an evaluation unit (14) or is connected to an evaluation unit (14) with which the signals from the sensors (15, 16) in particular are processed and be evaluated.

10. Pump according to claim 8 or 9, characterized in that the one or more sensors (15, 16) are designed as position sensors, for. B. as inductive, capacitive, magnetic or optical sensors.

11. Pump according to one of claims 8 to 10, characterized in that at least a first sensor (15) in the area of the first shaft (W1) and a second sensor (16) in the area of the second shaft (W2) or the pump element ( 2) are arranged.

12. Pump according to one of claims 9 to 11, characterized in that a threshold value or one or more comparison values for the phase shift can be stored in the evaluation unit (14) and that during operation when the threshold value is reached or exceeded or when tion of a temporal development of the phase shift, which deviates from a previously determined, characteristic development, a message can be generated, z. B. an optical and / or acoustic alarm signal.

13. Pump according to one of claims 9 to 12, characterized in that an evaluation algorithm is stored in the evaluation unit (14) with which predictions about the state of the connection (V) and/or predictions about maintenance times can be generated from continuously determined data. 22

14. Pump according to one of claims 9 to 13, characterized in that the monitoring device (13) is equipped or connected to a display device with which status information and / or warning signals can be displayed, z. B. acoustically or optically and / or that the monitoring device (13) is equipped or connected to an interface via which status data and / or forecasts and / or warnings to external devices, z. As computers, terminals or the like, are transferrable.

15. Pump according to one of claims 1 to 14, characterized in that the monitoring device (13) or the evaluation unit (14) is set up to determine the phase shift taking into account the rotational speed of the first shaft (W1) and/or the second shaft (W2) to analyze.

16. A method for monitoring the operation or the wear of a pump according to one of claims 1 to 15, wherein during operation the first shaft rotates at a first angle of rotation and the second shaft rotates at a second angle of rotation, each based on a common zero angle. characterized in that with the monitoring device, the state z. B. wear condition of the connection is monitored by a z. B. is determined by wear in the connection occurring phase shift between the first angle of rotation and the second angle of rotation.

17. The method according to claim 16, characterized in that the state of the pump or the state of a connection is determined continuously and that predictions are made from the determined state data using an algorithm 23 are generated about the condition of the pump or the connection and/or predictions about maintenance times.

18. The method according to claim 16 or 17, characterized in that status data, warning messages and / or maintenance forecasts via an interface to external devices, such. B. computers, terminals or the like are transmitted or queried by them.