Method of and apparatus for balancing a rotary body

Claim 1

A method of balancing a rotary body wherein the body includes spaces therein at various locations, comprising the steps of: rotating the body in first and second spaced bearings, the location of the first and second bearings defining first and second bearing planes, respectively; sensing the forces in the first and second bearing planes caused by rotation of the body; determining from the sensed forces the magnitude and angular location of a mass compensation to the rotary body which if effected at such location, would substantially statically balance the body; choosing an axial location for the mass compensation which would reduce to a minimum the dynamic unbalance of the body; comparing the minimum dynamic unbalance against a specified limit to determine whether such unbalance is acceptable; and effecting the mass compensation if the minimum dynamic unbalance is acceptable including the steps of removing material of a particular weight from the rotary body using a cutter by in turn determining from the particular weight and the angular and axial locations the amount by which the total volume of the rotary body is to be reduced by the cutter.

Claim 2

A method of balancing a rotary body wherein the body includes spaces therein at various locations, comprising the steps of: rotating the body in first and second spaced bearings, the location of the first and second bearings defining first and second bearing planes, respectively; sensing the forces in the first and second bearing planes caused by rotation of the body; determining from the sensed forces the magnitude and angular location of a mass compensation to the rotary body which if effected at such location, would substantially statically balance the body; choosing an axial location for the mass compensation which would reduce to a minimum the dynamic unbalance of the body; comparing the minimum dynamic unbalance against a specified limit to determine whether such unbalance is acceptable; and effecting the mass compensation if the minimum dynamic unbalance is acceptable including the steps of removing material of a particular weight from the rotary body using a cutter by in turn determining from the particular weight and the angular and axial locations the amount by which the total volume of the rotary body is to be reduced by the cutter.

Claim 8

A method of balancing a rotary body having voids therein at various locations, comprising the steps of: rotating the body in first and second spaced bearings, the location of the first and second bearings defining first and second bearing planes, respectively; sensing the forces in the first and second bearing planes caused by rotation of the body; determining the weight and angular location of a mass which, if removed from the body, would substantially statically balance the body; choosing an axial location of the mass to be removed which reduces to a minimum the dynamic unbalance of the body; and removing the weight at the determined angular and axial locations using a cutter including the step of determining from the weight and the angular and axial locations the amount by which the total volume of the rotary body is to be reduced by the cutter taking into account the voids in the body.

Claim 9

A method of balancing a rotary body having voids therein at various locations, comprising the steps of: rotating the body in first and second spaced bearings, the location of the first and second bearings defining first and second bearing planes, respectively; sensing the forces in the first and second bearing planes caused by rotation of the body; determining the weight and angular location of a mass which, if removed from the body, would substantially statically balance the body; choosing an axial location of the mass to be removed which reduces to a minimum the dynamic unbalance of the body; and removing the weight at the determined angular and axial locations using a cutter including the step of determining from the weight and the angular and axial locations the amount by which the total volume of the rotary body is to be reduced by the cutter taking into account the voids in the body.

Claim 14

A method of balancing a rotary body having voids therein, comprising the steps of: rotating the body in first and second spaced bearings, the location of the first and second bearings defining first and second bearing planes, respectively; sensing the forces in the first and second bearing planes caused by rotation of the body; determining first and second weights to be removed at first and second angular locations, respectively, which weight removals would substantially statically balance the body; selecting first and second axial planes in which the first and second weight removals are to be effected, respectively, which would reduce to a minimum the dynamic unbalance of the body; comparing the minimum dynamic unbalance against a predetermined limit to determine whether such unbalance in unacceptable; removing the weights at the determined angular and axial locations only if the minimum dynamic unbalance is acceptable using a cylindrical cutter; and determining the depth of cut for each weight removal required to remove the first and second weights from the rotary body including the steps of (a) selecting an initial depth of cut for the cutter, (d) deriving from the selected depth of cut an approximate indication of the total reduction in volume of the rotary body if the cutter cuts to the initial depth, (c) determining the total volume of the voids intercepted by the cutter if it cuts to the initial depth, (d) subtracting the total volume of the spaces from the total reduction in volume to calculate the volume of material which would be removed by the cutter, (e) comparing the volume of material removed against a desired volume equal to the weight to be removed divided by the density of the material, (f) selecting a different depth of cut and (g) repeating steps (b)-(f) until the volume of material removed approximates the desired volume.

Claim 15

A method of balancing a rotary body having voids therein, comprising the steps of: rotating the body in first and second spaced bearings, the location of the first and second bearings defining first and second bearing planes, respectively; sensing the forces in the first and second bearing planes caused by rotation of the body; determining first and second weights to be removed at first and second angular locations, respectively, which weight removals would substantially statically balance the body; selecting first and second axial planes in which the first and second weight removals are to be effected, respectively, which would reduce to a minimum the dynamic unbalance of the body; comparing the minimum dynamic unbalance against a predetermined limit to determine whether such unbalance in unacceptable; removing the weights at the determined angular and axial locations only if the minimum dynamic unbalance is acceptable using a cylindrical cutter; and determining the depth of cut for each weight removal required to remove the first and second weights from the rotary body including the steps of (a) selecting an initial depth of cut for the cutter, (d) deriving from the selected depth of cut an approximate indication of the total reduction in volume of the rotary body if the cutter cuts to the initial depth, (c) determining the total volume of the voids intercepted by the cutter if it cuts to the initial depth, (d) subtracting the total volume of the spaces from the total reduction in volume to calculate the volume of material which would be removed by the cutter, (e) comparing the volume of material removed against a desired volume equal to the weight to be removed divided by the density of the material, (f) selecting a different depth of cut and (g) repeating steps (b)-(f) until the volume of material removed approximates the desired volume.

Claim 20

An apparatus for reducing an unbalanced condition in a rotary body having voids therein, comprising: a pair of spaced bearings for supporting the rotary body; means for rotating the rotary body in the bearings, such rotation causing forces to be transmitted to the bearings; a force sensor coupled to each bearing for developing a signal representing the forces developed in the bearing; a computer coupled to the force sensors for determining the position of the rotary body when the forces in the bearings are at a maximum to in turn derive an indication of the magnitude and angle of the unbalanced condition; and a milling cutter controlled by the computer for effecting a mass compensation to the rotary body to reduce the unbalanced condition wherein the computer includes means for determining a weight to be removed from the rotary body at an angular and axial location on the body to effect the mass compensation and means for calculating the total volume of the rotary body which must be removed to effect the mass compensation from the determined weight, the angular and axial locations and taking into account the voids in the rotary body.

Claim 21

An apparatus for reducing an unbalanced condition in a rotary body having voids therein, comprising: a pair of spaced bearings for supporting the rotary body; means for rotating the rotary body in the bearings, such rotation causing forces to be transmitted to the bearings; a force sensor coupled to each bearing for developing a signal representing the forces developed in the bearing; a computer coupled to the force sensors for determining the position of the rotary body when the forces in the bearings are at a maximum to in turn derive an indication of the magnitude and angle of the unbalanced condition; and a milling cutter controlled by the computer for effecting a mass compensation to the rotary body to reduce the unbalanced condition wherein the computer includes means for determining a weight to be removed from the rotary body at an angular and axial location on the body to effect the mass compensation and means for calculating the total volume of the rotary body which must be removed to effect the mass compensation from the determined weight, the angular and axial locations and taking into account the voids in the rotary body.

Claim 29

A system for balancing a rotary part having voids therein, comprising: an unbalance detection unit, including means for rotating the rotary part, means for sensing the forces developed at first and second points on the part, means for selecting an angular and an axial location on the part at which material is to be removed to minimize the static and dynamic unbalance in the part, means for determining the weight of material to be removed at the selected location, and means for calculating the volume of material to be removed at the selected location to effect removal of the determined weight taking into account the voids in the rotary part; and an unbalance correction unit coupled to the unbalance detection unit, including a cutter, means for positioning the part relative to the cutter so that the cutter is positioned at the selected location on the part, and means for operating the cutter and the positioning means so that the calculated volume of material is removed from the part.

Claim 30

A system for balancing a rotary part having voids therein, comprising: an unbalance detection unit, including means for rotating the rotary part, means for sensing the forces developed at first and second points on the part, means for selecting an angular and an axial location on the part at which material is to be removed to minimize the static and dynamic unbalance in the part, means for determining the weight of material to be removed at the selected location, and means for calculating the volume of material to be removed at the selected location to effect removal of the determined weight taking into account the voids in the rotary part; and an unbalance correction unit coupled to the unbalance detection unit, including a cutter, means for positioning the part relative to the cutter so that the cutter is positioned at the selected location on the part, and means for operating the cutter and the positioning means so that the calculated volume of material is removed from the part.