Laser alignment head for use in shaft alignment

• US 5,684,578 A
• Filed: 06/23/1994
• Issued: 11/04/1997
• Est. Priority Date: 06/23/1994
• Status: Expired due to Term

• Current Assignee: CSI Technology Incorporated (Emerson Electric Company)
• Original Assignee: Computational Systems Incorporated (Emerson Electric Company)
• Inventors: Nower, Daniel L., Gaddis, David Q.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Laufer, Pinchus M.
• Application Number:
  US08/264,703
• Time in Patent Office: 1,230 Days
• Field of Search: 356/141.3, 356/152.1, 356/153, 356/139.04, 356/400, 356/139.09, 33/286, 33/645, 250/214 B
• US Class Current: 356/141.3
• CPC Class Codes: G01B 11/272 using photoelectric detection means

Abstract

The specification discloses a laser alignment head system for taking alignment data with respect to a pair of coupled shafts. Each alignment head includes a laser, a laser sensor for sensing a laser beam, an angle sensor for sensing the rotational orientation of the laser head, a computer and a transmitter for transmitting data from the laser head. The two laser heads are mounted on the two shafts in an opposing facing relationship with the laser beam of one head disposed on the laser sensor of the other head. As the shafts are rotated, the laser beam moves on the laser sensor and the laser sensor generates a position signal corresponding to such movement. Likewise, the angle sensor produces an angle signal corresponding to the rotational angle of the laser head as the shafts are rotated. The computer produces output data corresponding to the position signal and the rotational angle, and such data is transmitted to a receiver. An analyzer is interfaced with the receiver to receive the data and calculate misalignment information.

Claims

1. A laser alignment head system for takers multiple position alignment data with respect to two coupled shafts comprising:

two laser alignment heads each of said alignment heads comprising;

a laser generating a laser beam;

a laser sensor for sensing a laser beam and generating a position signal corresponding to the position of the laser beam on said sensor;

an angle sensor for sensing the rotational orientation of said laser head and generating an angle signal corresponding to the rotational orientation of said laser head;

a head circuit for receiving said position signal and angle signal and outputting data corresponding to the position and angle signal;

a wireless transmitter for transmitting said data generated by said head circuit;

a power supply providing a power signal to at least said laser sensor, said angle sensor, said head circuit, said transmitter and said laser; and

two shaft mounting brackets for securing said laser alignment heads to the shafts;

a wireless receiver means for receiving said data from said transmitter; and

an analyzer for receiving data from said receiver and determining offset and angularity between the two shafts based on data corresponding to the position and angle signals at multiple angular positions of said heads about the shaft axis.

2. The system of claim 1 further comprising:

said head circuit including a processor;

non-volatile memory associated with said processor for non-volatile storage of at least instructions for said processor and calibration data for said processor to use in generating said data from said position and angle signals; and

random access memory associated with said processor.

3. The system of claim 1 further comprising:

said head circuit including a digital processor;

said wireless transmitter further comprising a receiver;

wherein said wireless transmitter and said receiver comprise a transceiver;

said transceiver including;

a communications processor for receiving said data from said processor and for converting said data into driving signals for transmissions and converting a received signal into input for said processor;

at least one infrared light emitting diode connected to said communications processor so that said light emitting diode is turned on and off in accordance with said driving signals; and

at least one infrared detector connected to said communications processor, said detector generating a received signal corresponding to detected infrared emissions.

4. The system of claim 1 wherein said head circuit further comprises a processor and memory for automatically storing historical data at a plurality of angular positions, said historical data including a plurality of historical data pairs, each pair comprising an angle corresponding to the angle signal and a position corresponding to the position signal.

5. The system of claim 1, wherein said laser sensor further comprises an x-y sensor generating x and y coordinates corresponding to the position at which the laser beam is striking said x-y sensor.

6. The system of claim 1 wherein said angle sensor further comprises a liquid capacitance sensor circuit generating a signal having characteristics corresponding to the rotational orientation of the sensor.

7. The system of claim 1 further comprising an analyzer connected to the receiver, receiving said data from said receiver, and analyzing said data to determine misalignment of said shafts.

8. The system of claim 1 wherein said heads rotate about a stationary shaft.

9. The system of claim 1 wherein said shaft rotates and said heads remain fixed to said shaft.

10. A laser alignment head system for taking multiple position alignment data with respect to two coupled shafts comprising:

two laser alignment heads each of Said alignment heads comprising;

a laser generating a laser beam;

a laser sensor for sensing a laser beam and generating a position signal corresponding to the position of the laser beam on said sensor;

an angle sensor for sensing the rotational orientation of said laser head and generating an angle signal corresponding to the rotational orientation of said laser head;

a head circuit for receiving said position signal and angle signal and outputting data corresponding to the position and angle signal;

a wireless transmitter for transmitting said data generated by said head circuit;

a power supply providing a power signal to at least said laser sensor, said angle sensor, said head circuit, said transmitter and said laser; and

two shaft mounting brackets for rotatably securing said laser alignment heads to the shafts;

a wireless receiver means for receiving said data from said transmitter, said receiver comprising;

a receiver housing containing electronic circuitry for operating on said data;

a cable extending from said receiver housing and connected to said electronic circuitry; and

an external sensing unit connected to the cable on the end opposite from the receiver housing for receiving data from the transmitter and transmitting said data through said cable to said electronic circuitry in said receiver housing.

11. The system of claim 10 wherein said receiver further comprises an internal sensing unit disposed within said receiver housing for receiving data from the transmitter and supplying said data to said circuitry.

12. A laser alignment head system for being mounted on first and second substantially co-axial rotatable shafts for determining alignment information as to the first and second shafts as said shafts are rotated through a plurality of rotational orientations, comprising:

a master alignment head mounted on the first shaft and a slave alignment head mounted on the second shaft;

mounting brackets for mounting said master and slave alignment heads on the first and second shafts in a facing relationship;

said master alignment head and slave alignment head each comprising;

a computer for controlling the operation of the alignment head and for receiving, transmitting and storing data;

a pulsed laser for producing a pulsed laser beam at a pulse frequency with each pulse continuing for a pulse duration;

a laser position sensor for sensing the position of the laser beam on said position sensor in a direction radial to the shafts and producing a position signal corresponding to the position of the laser beam;

an angle sensor disposed in the alignment head for sensing the rotational orientation of the alignment head as said head is rotated on the shafts and producing an angle signal corresponding to the rotational orientation of the shafts;

a communications device for transmitting and receiving information to and from said alignment head;

said computer for receiving said position signal and said angle signal, for producing position data and angle data based on said position signal and angle signal, and for transmitting data corresponding to the position data and angle data to said communications device; and

a power supply for supplying power to said computer, pulsed laser, laser position sensor, angle sensor, and communications device;

said computer of said slave alignment head for analyzing the position signal to determine when said laser of said master alignment head is turned on and for substantially synchronizing the pulses of said laser of said slave alignment head with the pulses of said laser of said master alignment head at said pulse frequency; and

said computers of said master and slave alignment heads for sampling said position signals when said lasers of said master and slave alignment heads are turned on to produce "on" samples, for producing said position data based on said samples.

13. The system of claim 12 further comprising said computers of said master and slave alignment heads for sampling said position signals when said lasers are turned off to produce "off" samples and for determining the intensity of ambient light for each alignment head based on said "off" samples.

14. The system of claim 12 wherein each of said computers produces a plurality of readings, each reading being an average of a plurality of samples of said position and angle signals, and produces said calibrated position data based on said readings and said calibration data.

15. The system of claim 12 wherein said position sensor further comprises a sensor for detecting position of said laser beam in x and y directions and for generating a position signal having x and y components corresponding to the x and y directions, the y direction being radial with respect to the shafts and the x direction being perpendicular to the y direction and parallel to a tangent of the shafts.

16. The system of claim 15 wherein:

the x direction of said position sensor of said slave alignment head is disposed in a reverse linear orientation with respect to the x direction of said position sensor of said master alignment head and wherein said angle sensor of said slave alignment head is disposed in a reverse rotational orientation and is rotated in a reverse rotational direction as compared to said angle sensor of said master alignment head; and

said computers for said master and slave alignment heads correct the position and angle data to correct for the reverse linear orientation and reverse rotational orientation.

17. The system of claim 12 further comprising said computers storing predetermined calibration data and for producing calibrated position data and calibrated angle data based on said position and angle signals and the calibration data.

18. The system of claim 12 further comprising said computers of said master and slave alignment heads for storing historical data corresponding to the angle data and the position data at a plurality of angular orientations of the shafts and for transmitting the historical data to said communications device after the historical data is produced and stored.

19. A laser alignment head for being mounted on one of first and second rotatable shafts for use in determining alignment information as to the first and second shafts as said shafts are rotated through a plurality of rotational orientations, comprising:

a computer for controlling the operation of the alignment head and for receiving, transmitting and storing data;

a pulsed laser for producing a pulsed laser beam at a pulse frequency with each pulse continuing for a pulse duration;

a laser position sensor for sensing the position of the laser beam on said position sensor in a direction radial to the shafts and producing a position signal corresponding to the position of the laser beam;

an angle sensor disposed in the alignment head for sensing the rotational orientation of the alignment head as the head is rotated on the shafts and producing an angle signal corresponding to the rotational orientation of the shafts;

a communications device for transmitting and receiving information to and from said alignment head;

said computer for receiving said position signal and said angle signal, for producing position data and angle data based on said position-signal and angle signal, for storing historical data corresponding to the angle data and the position data at a plurality of angular orientations of the shafts, and for transmitting the historical data to said communications device after said historical data is produced and stored;

a power supply for supplying power to said computer, pulsed laser, laser position sensor, angle sensor, and communications device; and

mounting brackets for mounting the alignment head on one of the first and second shafts.

20. A laser alignment head for being mounted on one of first and second rotatable shafts for use in determining alignment information as to the first and second shafts as said shafts are rotated through a plurality of rotational orientations, comprising:

a computer for controlling the operation of the alignment head, for receiving, transmitting and storing data, and for storing predetermined calibration data;

a pulsed laser for producing a pulsed laser beam at a pulse frequency with each pulse continuing for a pulse duration;

a laser position sensor for sensing the position of the laser beam on said position sensor in a direction radial to the shafts and producing a position signal corresponding to the position of the laser beam;

an angle sensor disposed in the alignment head for sensing the rotational orientation of the alignment head as said head is rotated on the shafts and producing an angle signal corresponding to the rotational orientation of the shafts;

a wireless communications device for transmitting and receiving information to and from said alignment head;

said computer for receiving said position signal and said angle signal, for producing calibrated position data and calibrated angle data based on said position signal, angle signal and calibration data, and for transmitting the calibrated position data and calibrated angle data to said communications device;

a power supply for supplying power to said computer, pulsed laser, laser position sensor, angle sensor, and communications device;

mounting brackets for mounting the alignment head on one of the first and second shafts; and

an analyzer for receiving data from said computer and determining offset and angle based on data from multiple angular positions of heads about the shaft axis.

21. A laser alignment head system for being mounted on first and second substantially co-axial rotatable shafts for determining alignment information as to the first and second shafts as said shafts are rotated through a plurality of rotational orientations, comprising:

a master alignment head mounted on the first shaft and a slave alignment head mounted on the second shaft;

said master and slave alignment heads each comprising;

a computer for controlling the operation of the alignment head, for receiving, transmitting and storing data, and for storing predetermined calibration data;

a pulsed laser for producing a pulsed laser beam at a pulse frequency with each pulse continuing for a pulse duration;

a laser position sensor for sensing the position of the laser beam on said position sensor in x and y directions and for generating a position signal having x and y components corresponding to the position of the laser beam in the x and y directions, the y direction being radial with respect to the shafts and the x direction being perpendicular to the y direction and parallel to a tangent of the shafts;

an angle sensor disposed in the alignment head for sensing the rotational orientation of the alignment head as said head is rotated on the shafts and producing an angle signal corresponding to the rotational orientation of the shafts;

a communications device for transmitting and receiving information to and from said alignment head;

said computer for receiving said position signal and said angle signal, for producing calibrated position data and calibrated angle data based on said position signal, angle signal and calibration data, for storing historical data corresponding to the calibrated angle data and the calibrated position data at a plurality of rotational orientations of the shafts, for transmitting current data corresponding to the calibrated position data and calibrated angle data substantially as it is produced to said communications device, for transmitting historical data to said communications device after said historical data is produced and stored; and

a power supply for supplying power to said computer, pulsed laser, laser position sensor, angle sensor and communications device;

mounting brackets for mounting said master and slave alignment heads on the first and second shafts in a facing relationship such that the x direction of said position sensor of said slave alignment head is disposed in a reverse linear orientation with respect to the x direction of said position sensor of said master alignment head and such that said angle sensor of said slave alignment head is in a reverse rotational orientation and is rotated in a reverse rotational direction as compared to said angle sensor of said master alignment head;

said computers for said master and slave alignment heads for correcting the position and angle signals to correct for the reverse linear orientation and reverse rotational orientation;

said computer of said slave alignment head for analyzing the position signal to determine when said master laser is turned on and for substantially synchronizing the pulses of said laser of said slave alignment head with the pulses of said laser of said master alignment head at said pulse frequency;

said computers of said master and slave alignment heads for sampling said position signals when said lasers of said master and slave alignment heads are turned on and are substantially in the middle of the pulse duration to produce "on" samples, for producing said calibrated position data based on said "on" samples and said calibration data, and for sampling said position signals when said lasers are turned off to produce "off" samples and for determining ambient light conditions for each, alignment head based on said "off" samples;

said master and slave computers for producing a plurality of readings, each reading being an average of at least a plurality of samples of the position signal, and for producing said calibrated position data based on said readings and said calibration data; and

an analyzer for receiving data from said computer and determining offset and angle based on data corresponding to position and angle signals at multiple angular positions of said heads about the shaft axis.