State detection on eccentric screw pumps

Abstract

An eccentric screw pump hasa pump housing having a pump inlet opening and a pump outlet opening, a stator disposed in the pump housing, a rotor disposed in the stator, a drive unit comprising a drive motor and a driveshaft which for transmitting a torque connects the drive motor to the rotor, wherein the rotor for a rotating movement about a rotating axle is guided in the stator, a state sensor for detecting a state variable of the eccentric screw pump, where the state sensor, for detecting a state variable on the rotor or on the driveshaft, is disposed on the rotor or the driveshaft, or is connected to the rotor or the driveshaft by means of a signal line and is disposed so as to be spaced apart from the rotor or the driveshaft.

1 - 19 . (canceled) 
     
     
         20 . An eccentric screw pump, comprising:
 a pump housing having a pump inlet opening and a pump outlet opening;   a stator disposed in the pump housing;   a rotor disposed in the stator, wherein the rotor is adapted for rotational movement about a rotating axis and is guided in the stator;   a drive unit comprising a drive motor and a drive shaft transmitting a torque and connecting the drive motor to the rotor; and   a state sensor for detecting a state variable of the eccentric screw pump;   wherein the state sensor is disposed within the rotor or within the drive shaft and is connected to a state sensor data transmission module for wirelessly transmitting state data to a data receiver outside the eccentric screw pump; and wherein:
 the state sensor and the state sensor data transmission module are connected to an energy converter disposed on the rotor or on the drive shaft and configured for converting kinetic or thermal energy acting on the energy converter into electric energy; or 
 the state sensor is connected to the rotor or the drive shaft by a signal line and is disposed so as to be spaced apart from the rotor or the drive shaft. 
   
     
     
         21 . The eccentric screw pump as claimed in  claim 20 , wherein the state sensor is connected so as to be wired to an electronic evaluation unit by way of a sensor cable; and
 wherein the sensor cable runs within a portion of the drive shaft and/or within a portion of the rotor; or   wherein the sensor cable runs through the drive shaft.   
     
     
         22 . The eccentric screw pump as claimed in  claim 20 , wherein:
 the drive shaft is a wobble shaft which at an end thereof that points toward the drive motor is connected to the drive motor for rotation about a drive axis; and   at an end thereof that points toward the rotor is connected to the rotor for rotation about a rotor axis and for a superimposed rotation about a stator axis spaced apart from the rotor axis.   
     
     
         23 . The eccentric screw pump as claimed in  claim 22 , wherein the wobble shaft has a wobble shaft central portion, a first universal joint, and a second universal joint, wherein:
 the first universal joint is inserted between the wobble shaft central portion and the drive motor; and   the second universal joint is inserted between the wobble shaft central portion and the rotor.   
     
     
         24 . The eccentric screw pump as claimed in  claim 23 , wherein a sensor cable is routed:
 into the first and/or the second universal joint;   through the first universal joint; or   about the first and/or the second universal joint.   
     
     
         25 . The eccentric screw pump as claimed in  claim 23 , wherein the first universal joint is enclosed by a first sealing boot and the second universal joint is enclosed by a second sealing boot, or wherein the first and the second universal joint and the wobble shaft are enclosed by a sealing sleeve; and in that,
 for detecting the pressure in the first and/or second sealing boot or in the sealing sleeve,
 a pressure sensor is disposed in the first and/or the second sealing boot or in the sealing sleeve; or 
 a pressure line is routed into the first and/or the second sealing boot or into the sealing sleeve, and a pressure sensor is fluidically connected to the pressure line; and 
   the pressure sensor for signal transmission is connected to an evaluation unit and the pressure sensor is configured for detecting the pressure within the first and/or the second sealing boot or within the sealing sleeve.   
     
     
         26 . The eccentric screw pump as claimed in  claim 20 , wherein the state sensor is connected to an electronic evaluation unit and the electronic evaluation unit is configured for:
 determining a variance of an actual state detected by the state sensor by the state sensor data from a predetermined target state;   comparing this determined variance with a predetermined permissible variance; and   when the determined variance exceeds the permissible variance, emitting an alarm signal.   
     
     
         27 . The eccentric screw pump as claimed in  claim 26 , wherein the electronic evaluation unit is configured for:
 receiving a state sensor signal as the actual state; and   comparing the state sensor signal with a stored normal state sensor signal as the target state, wherein the electronic evaluation is further configured for:   calculating the determined variance as the difference between the state sensor signal and the stored normal state sensor signal;   utilizing a predetermined permissible variance value as the predetermined permissible variance; and   emitting an alarm signal as a value alarm signal.   
     
     
         28 . The eccentric screw pump as claimed in  claim 26 , wherein the electronic evaluation unit is configured for:
 receiving state sensor signals;   determining from at least two temporally sequential state sensor signals a state variation value as the actual state; and   comparing the state variation value with a stored normal state variation value as the target state, wherein the electronic evaluation is further configured for: 
 calculating the determined variance as a difference between the state variation value and the stored normal state variation value; 
 utilizing a predetermined permissible variance variation value as the predetermined permissible variance; and 
 emitting a variation alarm signal as the alarm signal. 
   
     
     
         29 . The eccentric screw pump as claimed in  claim 26 , wherein the electronic evaluation unit is configured for:
 receiving state sensor signals;   determining from at least three temporally sequential state sensor signals a state variation speed as the actual state; and   comparing the state variation speed with a stored normal state variation speed as the target state, wherein the electronic evaluation is further configured for:
 calculating the determined variance as the difference between the state variation speed and the stored normal state variation speed; 
 utilizing a predetermined permissible speed variance as the predetermined permissible variance; and 
 emitting a variation speed alarm signal as the alarm signal. 
   
     
     
         30 . The eccentric screw pump as claimed in  claim 26 , wherein the electronic evaluation unit is configured for:
 comparing a plurality of temporally sequential actual states with a plurality of temporally sequential target states;   calculating from the comparison a variance characteristic value as the determined variance; and   utilizing a predetermined permissible variance characteristic value as the predetermined permissible variance.   
     
     
         31 . The eccentric screw pump as claimed in  claim 26 , wherein the eccentric screw pump has a rotor having a conical envelope and a conically tapered stator interior, and the rotor and the stator are adjustable relative to one another in the axial direction by an axial actuating drive, and wherein the electronic evaluation unit for signal transmission is connected to the axial actuating drive and configured for:
 actuating the actuating drive so as to carry out an axial adjustment between the rotor and the stator; and   detecting during the axial adjustment procedure a plurality of temporally sequential state sensor signals of the state sensor.   
     
     
         32 . The eccentric screw pump as claimed in  claim 20 , wherein the energy converter is selected from:
 a converter based on an electromagnetic induction principle, which converts a relative rotating movement of the rotor or of the wobble shaft in relation to a pump housing into electric energy;   a converter based on an electromagnetic induction principle, which converts a reciprocating acceleration of the rotor or of the wobble shaft resulting from the rotation of the rotor or of the wobble shaft about a rotor axis and from the rotation of the rotor about an eccentric axis into electric energy; or   a converter based on a thermo-electric principle, which converts a temperature gradient into electric energy, wherein the converter is disposed in a region exposed to a temperature gradient between the conveyed medium and a pump component.   
     
     
         33 . The eccentric screw pump as claimed in  claim 20 , further comprising two state sensors disposed on two mutually spaced apart positions disposed on the rotor, and the positions have a phase shift of a measured state variable. 
     
     
         34 . The eccentric screw pump as claimed in  claim 20 , wherein the state sensor comprises:
 a temperature sensor;   a pressure sensor;   a vibration sensor; or   an acceleration sensor.   
     
     
         35 . A method for controlling an eccentric screw pump comprising a pump housing having a pump inlet opening and a pump outlet opening, the method comprising the steps of:
 driving a rotor for a rotational movement about a rotating axis in a stator by a drive unit and a drive shaft;   pumping a medium from a pump inlet through the stator to a pump outlet by way of a displacement effect between the rotor and the stator; and   detecting a state variable of the eccentric screw pump, wherein:   the state variable is detected by means of a state sensor which is:
 disposed within the rotor or within the drive shaft and connected to a state sensor data transmission module for wirelessly transmitting state data to a data receiver outside the eccentric screw pump, wherein the state sensor and the state sensor data transmission module for receiving electric energy are connected to an energy converter disposed on the rotor or on the drive shaft and configured for converting kinetic or thermal energy acting on the energy converter into electric energy; or 
 connected to the rotor or the drive shaft by means of a signal line and is disposed so as to be spaced apart from the rotor or the drive shaft; and wherein the state variable is detected on the rotor or on the drive shaft. 
   
     
     
         36 . The method as claimed in  claim 35 , wherein:
 the eccentric screw pump has a rotor having a conical envelope and a conically tapered stator interior, and the rotor and the stator are adjusted relative to one another in the axial direction by means of an axial actuating drive;   the rotor and the stator are axially mutually adjusted by means of the axial actuating drive;   a plurality of temporally sequential state sensor signals of the state sensor are detected during the axial adjustment procedure; and   the state variable is detected during the pumping procedure and the axial adjustment procedure is carried out during the pumping procedure.   
     
     
         37 . An eccentric screw pump, comprising:
 a pump housing having a pump inlet opening and a pump outlet opening;   a stator disposed in the pump housing;   a rotor disposed in the stator;   a drive unit comprising a drive motor and a drive shaft mechanically coupled with the rotor for transmitting a torque to the rotor, wherein the rotor is guided in the stator for rotational movement about a rotating axis; and   a state sensor for detecting a state variable of the eccentric screw pump, wherein the state sensor is disposed within the rotor or within the drive shaft and is connected to a state sensor data transmission module for wirelessly transmitting state data to a data receiver outside of the eccentric screw pump;   wherein the state sensor and the state sensor data transmission module for receiving electric energy are connected to an energy converter disposed on the rotor or on the drive shaft, the energy converter being configured for converting kinetic or thermal energy acting on the energy converter into electric energy; or   wherein the state sensor is connected by a signal line to the rotor or the drive shaft and is disposed so as to be spaced apart from the rotor or the drive shaft.