DRIVE CONTROL METHOD AND DRIVE SYSTEM OPERATING ACCORDING TO SAID METHOD

• US 20160023218A1
• Filed: 08/06/2013
• Published: 01/28/2016
• Est. Priority Date: 01/16/2013
• Status: Abandoned Application

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: KUBE, ANDREAS
• Application Number:
  US14/761,196
• Publication Number:
  US 20160023218A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B02C 15/007 Mills with rollers pressed against a rotary horizontal disc with pendularly mounted rollers B02C15/04
• CPC Class Codes: B02C 15/02 Centrifugal pendulum-type mills
• CPC Class Codes: B02C 15/06 Mills with rollers forced against the interior of a rotary ring, e.g. under spring action B02C15/04 takes precedence
• CPC Class Codes: B02C 2015/008 Roller drive arrangements
• CPC Class Codes: B02C 25/00 Control arrangements specially adapted for crushing or disintegrating
• CPC Class Codes: H02P 31/00 Arrangements for regulating or controlling electric motors not provided for in groups H02P1/00 - H02P5/00, H02P7/00 or H02P21/00 - H02P29/00

Abstract

In a drive control method for a vertical mill having a grinding plate rotatable about the vertical axis and being drivable by a drive train that includes an electric motor and a gearbox, a rotational speed of the grinding plate is varied cyclically, especially intermittently. A corresponding drive system operating according to the method is also disclosed.

Claims

1-13. -13. (canceled)

14. A drive control method for a vertical roller mill having a grinding table rotatable about a vertical axis, the method comprising:

driving the grinding table by way of a drive train having an electric motor and a gearbox, and

cyclically varying a rotation speed of the grinding table.

15. The method of claim 14, wherein the cyclical variation of the rotation speed of the grinding table is activated under time control for a predefined period of time.

16. The method of claim 15, wherein the rotation speed is activated at predefined points in time.

17. The method of claim 16, wherein the predefined points in time are equidistant.

18. The method of claim 14, wherein the cyclical variation of the rotation speed of the grinding table is activated in response to a fluctuation of vibration-relevant measured values that exceeds a predefined limit.

19. The method of claim 18, wherein the vibration-relevant measured values comprise at least one of a rotation speed of a rotating component of the vertical roller mill and a driving torque and supporting torque operating in or on the gearbox.

20. The method of claim 14, wherein the rotation speed is cyclically varied by periodically varying of the rotation speed, and wherein at least one of an amplitude and a period duration of the periodic variation of the rotation speed of the grinding table is increased or reduced as a function of a fluctuation of vibration-relevant measured values that exceeds a predefined limit.

21. The method of claim 20, wherein the vibration-relevant measured values comprise at least one of a rotation speed of a rotating component of the vertical roller mill and a driving torque and supporting torque operating in or on the gearbox.

22. The method of claim 14, wherein the rotation speed is cyclically varied by periodically varying of the rotation speed with a rotation speed profile selected from a sinusoidal profile, a rectangular profile, a square-wave profile and a ramp-profile.

23. The method of claim 22, wherein a change in a signal waveform with which the rotation speed of the grinding table is periodically varied is initiated when a fluctuation of vibration-relevant measured values exceeds a predefined limit.

24. The method of claim 23, wherein the vibration-relevant measured values comprise at least one of a rotation speed of a rotating component of the vertical roller mill and a driving torque and supporting torque operating in or on the gearbox.

25. The method of claim 14, wherein the electric motor is fed by a frequency converter, and wherein the rotation speed of the grinding table is cyclically varied by appropriate control of the frequency converter.

26. The method of claim 14, wherein vibration-relevant measured values are obtained by measuring with a sensor system a rotation speed of a rotating component of the drive train or at least one driving torque or supporting torque, or both, operating in or on the gearbox.

27. A computer program product embodied on a non-transitory storage medium and comprising a computer program having program instructions which, when loaded into a memory of a control device controlling a drive for a vertical roller mill having a grinding table driven by at least one electric motor and a drive train comprising at least one gearbox for rotation about a vertical axis, and executed by the control device, causes the control device to cyclically vary a rotation speed of the grinding table.

28. A non-transitory digital storage medium comprising a computer program having program instructions which, when loaded into a memory of a programmable controller controlling a drive system for a vertical roller mill having a grinding table driven by at least one electric motor and a drive train comprising at least one gearbox for rotation about a vertical axis, and executed by the programmable controller, cause the programmable controller to cyclically vary a rotation speed of the grinding table.

29. A drive system for a vertical roller mill having a grinding table rotatable about a vertical axis, the drive system comprising:

an electric motor driving the grinding table,

a frequency converter feeding the electric motor,

a gearbox arranged between the electric motor and the grinding table, and

a rotation speed varying device configured to cyclically vary a rotation speed of the grinding table.

30. The drive system of claim 29, further comprising a sensor system for measuring vibration-relevant measured values.

31. The drive system of claim 30, wherein the vibration-relevant measured values comprise at least one of a rotation speed of a rotating component of the vertical roller mill and a driving torque and supporting torque operating in or on the gearbox.

32. A controller of a drive system of a vertical roller mill having a grinding table rotatable about a vertical axis, wherein the drive system comprises an electric motor driving the grinding table, a frequency converter feeding the electric motor, and

a gearbox arranged between the electric motor and the grinding table, the controller comprising a processing unit and a memory into which a computer program having program instructions which, when loaded into the memory and executed by the processing unit, cause the controller during operation of the controller to cyclically vary a rotation speed of the grinding table.