Balancing machine and method for calibrating the same

Claim 2

In a balancing machine of the type wherein a part is rotated about an axis thereof to determine a first unbalance in the part and wherein correction for first unbalance is made by adding or subtracting weight in at least two correction planes that are transverse to said axis and spaced apart along said axis, and wherein said first unbalance is sensed by at least a pair of transducers also spaced apart along said axis and disposed at positions other than said correction planes, the combination comprising means for generating an electrical reference signal representing a predetermined unbalance, means for proportioning said signal into at least two unequal component signals whose ratio is a function of the distances between one of said correction planes and first and second reference locations spaced apart axially along said axis and disposed at positions other than said correction planes, and first and second vibratory drive means responsive respectively to said first and second component signals and operative to apply respective forces at said first and second locations to simulate said predetermined unbalance at said one correction plane.

Claim 3

The balancing machine set forth in claim 1 wherein said first reference location is spaced axially of said part from said one correction plane in a first direction along said axis and said second location is spaced axially of said part from said one correction plane in a second direction along said axis, and wherein said signal generating means comprises a source of repetitive electrical reference signals having a predetermined amplitude and a predetermined frequency and said signal proportioning means is responsive to said reference signal to develop said component signals having repetitive waveforms that are in phase with each other so that said forces are applied in phase at said first and second locations.

Claim 4

The balancing machine set forth in claim 1 wherein said first and said second reference locations are spaced axially of said part from said one correction plane in a first direction along said axis, and wherein said signal generating means comprises a source of repetitive reference signals having a predetermined amplitude and a predetermined frequency and said signal proportioning means is responsive to said reference signal to develop said component signals with repetitive waveforms that are opposite in phase to each other so that said forces are applied out of phase at said first and second locations.

Claim 5

The balancing machine set forth in claim 1 wherein said signal proportioning means comprises first adjustable impedance means coupled to said reference signal and operable by the operator of said machine to develop an intermediate signal that represents the axial separation between said first and second locations, and second variable impedAnce means responsive to said intermediate signal and operable by the operator of the balancing machine for developing one of said component signals by selecting a portion of said intermediate signal that represents the separation between one of said reference locations and said one correction plane.

Claim 6

The balancing machine set forth in claim 4 wherein said signal proportioning means comprises third variable impedance means responsive to said intermediate signal and operable by the operator of the balancing machine for developing the other of said component signals by selecting a portion of said intermediate signal according to the separation between the other of said reference locations and said one correction plane.

Claim 7

The balancing machine set forth in claim 4 wherein said signal proportioning means comprises amplifier means having an input terminal and an output terminal, said reference signal is applied to said input terminal, feedback means coupled between the output terminal of said amplifier and said amplifier input terminal, and wherein said first variable impedance means is connected in said feedback means to vary the gain of said amplifier according to the separation between said first and second reference locations.

Claim 8

The balancing machine set forth in claim 6 wherein said first adjustable impedance means comprises a first voltage divider means having first and second terminals and an adjustable wiper coupled to said divider at a point electrically between said first and second terminals, one of said voltage divider terminals is connected to said amplifier output terminal to develop said intermediate signal across said first and second voltage divider terminals and said feedback means is coupled to said wiper.

Claim 9

The balancing machine set forth in claim 7 wherein said second impedance means comprises a second voltage divider means having first and second terminals connected across said first voltage divider means and an adjustable wiper to develop said one component signal.

Claim 10

The balancing machine set forth in claim 8 wherein said signal proportioning means further comprises third voltage divider means having first and second terminals connected across said first voltage divider means and an adjustable wiper to develop the other component signal.

Claim 11

The balancing machine set forth in claim 9 wherein said signal proportioning means further comprises switch means coupled to said first and said second voltage divider means and to one of said drive means and operable in one switch position to couple said one component signal from said second voltage divider means to said one drive means and operable in another switch position to couple said other component signal from said third voltage divider means to said one drive means.

Claim 12

The balancing machine set forth in claim 4 wherein said signal proportioning means further comprises summing means responsive to said one component signal and said reference signal to develop the other component signal.

Claim 13

The balancing machine set forth in claim 11 wherein said signal proportioning means has a first output terminal coupled to one of said drive means and a second output terminal coupled to the other of said drive means, and wherein said signal proportioning means further comprises switch means operable in one switch position to develop said first component signal at said first output terminal and said second component signal at said second output terminal and operable in another switch position to develop said second component signal at said first output terminal and said first component signal at said second output terminal.

Claim 14

The balancing machine set forth in claim 4 wherein said signal proportioning means has a first output terminal coupled to one of said drive means and a second output terminal coupled to the other of said drive means, and wherein said signal proportioning means further comprises switch means operable in one switch position to develop said first component signal at said First output terminal and said second component signal at said second output terminal and operable in another switch position to develop said second component signal at said first output terminal and said first component signal at said second output terminal.

Claim 15

The balancing machine set forth in claim 1 wherein said first component signal is a function of a first distance between said one correction plane and said first reference location and said second component signal is a function of a second distance between the other correction plane and said first reference location, and wherein said combination further comprises switch means operable in one switch position to apply said first component signal to said first drive means and said second component signal to said second drive means and operable in a second switch position to apply said first component signal to said second drive means and said second component signal to said first drive means.

Claim 16

The balancing machine set forth in claim 1 further comprising first and second means for supporting said part for translation in a first predetermined plane, said first and second support means being spaced axially of said part, and wherein at least one of said drive means is mounted on said balancing machine at a fixed position axially of said part relative to one of said support means.

Claim 17

The balancing machine set forth in claim 15 wherein the other of said drive means is mounted on said balancing machine at a fixed position axially of said part relative to the other of said support means.

Claim 18

The balancing machine set forth in claim 15 wherein said first support means comprises a carrier mounted on said balancing machine for generally rectilinear translation in a first plane transverse to said axis at said first reference location, said first vibratory drive means comprises vibrator means mounted on said balancing machine and having an actuator adapted to reciprocate in said first transverse plane at said first reference location, and means drivingly connecting said actuator to said carrier at a location in close proximity to a second predetermined plane containing said axis and being perpendicular to said first transverse plane.

Claim 19

The balancing machine set forth in claim 17 wherein said connecting means comprises a rigid rod having a first transverse cross section and a length of stiff wire of substantially smaller transverse cross section and aligned axially with said rod to transmit said driving force from said actuator to said carrier, said wire being resiliently flexible to permit limited shifting of said carrier relative to said actuator.

Claim 20

The balancing machine set forth in claim 1 wherein said combination further comprises means for mixing a first pickup signal from said first transducer with a portion of a second pickup signal from said second transducer to provide a first modified output signal, said mixing means including switch means operable in one switch position to provide said first modified output signal and operable in a second switch position to cause said mixing means to mix a third pickup signal from said second transducer with at least a portion of a fourth pickup signal from said first transducer to provide a second modified output signal, said first component signal being a function of a first distance between said first correction plane and said first reference location, said second component signal being greater than said first component signal and being a function of a second distance between said second correction plane and said first reference location, and wherein said combination further includes second switch means operable in its first switch position to apply said first component signal to said first drive means and said second component signal to said second drive means and operable in its second switch position to apply said first component signal to said second drive means and said second component signal to said first drive means.

Claim 21

In apparatus for usE with a balancing machine wherein first and second support means are adapted to support a part thereon during a balancing operation, said first and second support means being spaced apart axially of said part, and first and second transducer means are responsive to unbalance forces on said part during a balancing operation to provide first and second pickup signals that vary according to unbalance of said part, the improvement comprising means for calibrating said pickup signals including electrical signal generating means for providing a sinusoidal reference signal having a predetermined amplitude and a predetermined frequency representing a predetermined unbalance, first circuit means responsive to said reference signal to develop two component signals having a predetermined ratio therebetween, said ratio being other than a one-to-one ratio and being determined by a first correction location on said part at which unbalance corrections are to be made, and first and second vibratory drive means operatively coupled to said first and second support means respectively and responsive respectively to said first and second component signals and operative to apply respective drive forces to said part at first and second positions spaced axially of said part to simulate said predetermined unbalance at said first location.

Claim 22

In apparatus for usE with a balancing machine wherein first and second support means are adapted to support a part thereon during a balancing operation, said first and second support means being spaced apart axially of said part, and first and second transducer means are responsive to unbalance forces on said part during a balancing operation to provide first and second pickup signals that vary according to unbalance of said part, the improvement comprising means for calibrating said pickup signals including electrical signal generating means for providing a sinusoidal reference signal having a predetermined amplitude and a predetermined frequency representing a predetermined unbalance, first circuit means responsive to said reference signal to develop two component signals having a predetermined ratio therebetween, said ratio being other than a one-to-one ratio and being determined by a first correction location on said part at which unbalance corrections are to be made, and first and second vibratory drive means operatively coupled to said first and second support means respectively and responsive respectively to said first and second component signals and operative to apply respective drive forces to said part at first and second positions spaced axially of said part to simulate said predetermined unbalance at said first location.

Claim 23

In the method of calibrating a balancing machine of the type wherein a first part under test is supported on first and second support means spaced apart axially of said part, first and second transducer means are responsive to unbalance forces on said part during a balancing operation to provide first and second pickup signals that vary according to unbalance of said part, and said pickup signals are calibrated to indicate said unbalance of said part, that improvement wherein said pickup signals are calibrated by establishing first and second reference locations spaced axially of said part, establishing first and second correction locations spaced axially of said part, determining a first distance between said first reference location and one of said correction locations, determining a second distance between said first reference location and said second correction location, determining a third distance between said first and said second reference locations, causing said part to vibrate in a first mode in a predetermined plane without rotating said part by applying at one of said reference locations a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said first dimension to said third dimension while simultaneously applying at the other of said reference locations a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said second dimension to said third dimension to simulate a predetermined unbalance at one of said correction planes and then causing said part to vibrate in a second mode in said predetermined plane without rotating said part by applying at said one reference location a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said second dimension to said third dimension while simultaneously applying at said other reference location a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said first dimension to said third dimension to simulate a predetermined unbalance at the other of said correction planes.

Claim 24

In the method of calibrating a balancing machine of the type wherein a first part under test is supported on first and second support means spaced apart axially of said part, first and second transducer means are responsive to unbalance forces on said part during a balancing operation to provide first and second pickup signals that vary according to unbalance of said part, and said pickup signals are calibrated to indicate said unbalance of said part, that improvement wherein said pickup signals are calibrated by establishing first and second reference locations spaced axially of said part, establishing first and second correction locations spaced axially of said part, determining a first distance between said first reference location and one of said correction locations, determining a second distance between said first reference location and said second correction location, determining a third distance between said first and said second reference locations, causing said part to vibrate in a first mode in a predetermined plane without rotating said part by applying at one of said reference locations a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said first dimension to said third dimension while simultaneously applying at the other of said reference locations a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said second dimension to said third dimension to simulate a predetermined unbalance at one of said correction planes and then causing said part to vibrate in a second mode in said predetermined plane without rotating said part by applying at said one reference location a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said second dimension to said third dimension while simultaneously applying at said other reference location a force which varies sinusoidally and has a peak amplitude proportional to the ratio of said first dimension to said third dimension to simulate a predetermined unbalance at the other of said correction planes.

Claim 25

The method set forth in claim 21 wherein said forces are developed by generating a sinusoidal electrical signal having a predetermined amplitude and a predetermined frequency representing a predetermined unbalance, proportioning said sinusoidal signal into component signals according to said ratios and then vibrating said part in response to said component signals.

Claim 26

The method set forth in claim 21 wherein one of said transducer means is at a position fixed in a direction axially of said part relative to said one reference location and the other transducer means is at a position fixed in a directioN axially of said part relative to said other reference location, and wherein said pickup signals are calibrated to indicate unbalance of a different part by maintaining said relative position between said one transducer means and said one reference location constant, maintaining said relative position between said other transducer means and said other reference location constant while causing said different part to vibrate in modes corresponding to said first mode and said second mode for said first part by varying said force ratios according to the positions of corresponding reference locations and correction locations selected for said different part.