Means for dynamically balancing a gyroscope

Claim 2

In a free-rotor flexure suspended gyroscope having a drive shaft, a gimbal supported rotor mounted at one end of the shaft and a drive motor hub assembly mounted at the other end of the shaft, wherein the improvement comprises: means for cancelling the dynamic unbalance resulting from the displacement between the mass center of said gimbal supported rotor and the center of rotation of said shaft, said means comprising A pair of dynamic balancing masses associated with said motor hub assembly.

Claim 3

The apparatus of claim 1 wherein said pair of masses is fixedly supported by said motor hub assembly such that each mass in said pair is displaced from said center of rotation and is in diametrical opposition to the other mass in said pair.

Claim 4

The apparatus of claim 2 wherein the masses in said pair are different and are axially spaced from each other by a predetermined amount whereby the resultant of the forces and torques acting on said drive shaft and being produced by said displacement and each of said different masses during rotation of said shaft are zero.

Claim 5

The apparatus of claim 3 wherein said motor hub assembly includes at least a pair of recesses each one of which is parallel to the axis of rotation of said drive shaft and is radially displaced therefrom and wherein each of said masses comprises a cylindrical element adapted for disposition within each said recess, respectively.

Claim 6

The apparatus of claim 3 wherein said pair of masses comprises segments of a ring disposed within a cylindrical recess in said motor hub assembly, said recess being coaxially located relative to the axis of rotation of said assembly.

Claim 7

In a free-rotor flexure suspended gyroscope having a drive shaft, a gimbal supported rotor mounted on one end of said shaft and a drive motor hub assembly mounted on the other end of the shaft, the method of cancelling the dynamic unbalance of said gyroscope resulting from the noncoincidence between the mass axis of said gimbal supported rotor and the rotational axis of said drive shaft comprising the steps of: locating the plane of unbalance including the aforementioned axes, determining the amount of noncoincidence between the aforementioned axes and therefore the unbalance force acting on said shaft, affixing a first weighted element to the motor hub assembly offset from the rotation axis in the plane of unbalance and diametrically opposed to the unbalance force direction, affixing a second weighted element to the motor hub assembly in symmetrical diametrical opposition to said first weighted element with respect to said rotation axis, the sum of forces produced by said offset weighted elements being equal to and opposite to said unbalance force during rotation of said shaft, and axially displacing one weighted element with respect to the other in the plane of unbalance until the resultant torques acting on the shaft with regard to a predetermined reference plane and being produced by the unbalance force and each weighted element respectively are equal to zero during rotation of the shaft.

Claim 8

In a free-rotor flexure suspended gyroscope having a drive shaft, a gimbal supported rotor mounted on one end of said shaft and a drive motor hub assembly mounted on the other end of the shaft, the method of cancelling the dynamic unbalance of said gyroscope resulting from the noncoincidence between the mass axis of said gimbal supported rotor and the rotational axis of said drive shaft comprising the steps of: locating the plane of unbalance including the aforementioned axes, determining the amount of noncoincidence between the aforementioned axes and therefore the unbalance force acting on said shaft, affixing a first weighted element to the motor hub assembly offset from the rotation axis in the plane of unbalance and diametrically opposed to the unbalance force direction, affixing a second weighted element to the motor hub assembly in symmetrical diametrical opposition to said first weighted element with respect to said rotation axis, the sum of forces produced by said offset weighted elements being equal to and opposite to said unbalance force during rotation of said shaft, and axially displacing one weighted element with respect to the other in the plane of unbalance until the resultant torques acting on the shaft with regard to a predetermined reference plane and being produced by the unbalance force and each weighted element respectively are equal to zero during rotation of the shaft.