US 7,841,583 B1 · System and method for detecting a discontinuity in a mechanical drive train

Abstract

Two incremental shaft encoders are mounted on the two extreme ends of a mechanical drive train. The encoders generate data which is representative of the rotational speed of the drive train component proximate to where the encoder is mounted. The data from the encoders is communicated to a logic unit associated with operation of the drive train, such as a variable frequency motor drive (VFD). Software in the logic unit monitors and compares the speed of both encoders. An encoder resolution setting and a gear ratio are entered into the software parameters. If a difference in speeds (as monitored and indicated by the encoders) is greater than a preset value for a period longer than a preset time period, the logic unit displays an error message and a programmed action (such as motor shutdown and load braking) is executed.

Claims32

Dependent claims

A method of detecting a discontinuity in a mechanical drive train, the mechanical dive train including an electric motor, the method comprising the steps of:

controlling the electric motor with a variable frequency drive (VFD);
generating a first pulse train representative of a first rotational speed of a first drive train component positioned at a first end of the drive train;
generating a second pulse train representative of a second rotational speed of a second drive train component positioned at a second end of the drive train;
communicating the first and second pulse trains to the VFD;
processing the first pulse train within the VFD to determine the first rotational speed;
processing the second pulse train within the VFD to determine the second rotational speed;
comparing the first rotational speed with the second rotational speed;
and
if the first rotational speed differs from the second rotational speed by a predetermined amount, initiating a discontinuity detected action from the VFD.

6 more elements

A mechanical drive train employed by a machine to transmit power from a first end of the mechanical drive train to a second end, the mechanical drive train comprising:

an electrical motor on the first end of the drive train;
at least one rotating component connected in sequence to the electrical motor;
a load positioned on the second end of the drive train opposite from the motor, so as to receive power transmitted by the motor along the sequence of connected rotating components;
a first sensor positioned proximate the first end of the drive train, the first sensor operable to generate data representative of a first rotational speed;
a second sensor positioned proximate the second end of the drive train, the second sensor operable to generate data representative of a second rotational speed;
a variable frequency motor drive (VFD), operably coupled to the motor;
and
the VFD further comprising a logic unit, the logic unit comprising hardware and software operable to:
receive the data generated by the first and second sensors,
process the data,
compare the first and second rotational speeds and
implement a discontinuity detected action.

9 more elements

Dependencies are inferred from the claim text.

System and method for detecting a discontinuity in a mechanical drive train

Life of this patent

System and method for detecting a discontinuity in a mechanical drive train

Life of this patent

Abstract

Claims32