Method and apparatus for determining bearing preload in a gear train

Claim 1

A method of determining the drag torque exerted by bearings supporting meshing gears in a gear train wherein there is a certain backlash between the teeth of the meshing gears and the meshing gears have different decelerations, the method comprising the steps: a. connecting a rotational power input to the gear train; b. disconnecting the rotational power input from the gear train so that the gears momentarily rotate freely of each other while the backlash between the gears is taken up because of their different decelerations; c. measuring the deceleration of one of the meshing gears while the backlash is being taken up; and d. determining the drag torque of the bearing supporting the one gear from the measured deceleration.

Claim 2

A method of determining the drag torque exerted by bearings supporting meshing gears in a gear train wherein there is a certain backlash between the teeth of the meshing gears and the meshing gears have different decelerations, the method comprising the steps: a. connecting a rotational power input to the gear train; b. disconnecting the rotational power input from the gear train so that the gears momentarily rotate freely of each other while the backlash between the gears is taken up because of their different decelerations; c. measuring the deceleration of one of the meshing gears while the backlash is being taken up; and d. determining the drag torque of the bearing supporting the one gear from the measured deceleration.

Claim 3

A method of determining the drag torque exerted by bearings supporting meshing gears in a gear train wherein there is a certain backlash between the teeth of the meshing gears and the meshing gears have different decelerations, the method comprising the steps: a. connecting a rotational power input to the gear train; b. disconnecting the rotational power input from the gear train so that the gears momentarily rotate freely of each other while the backlash between the gears is taken up because of their different decelerations; c. measuring the deceleration of one of the meshing gears while the backlash is being taken up; and d. determining the drag torque of the bearing supporting the one gear from the measured deceleration.

Claim 4

A method of determining the drag torque exerted by bearings supporting meshing gears in a gear train wherein there is a certain backlash between the teeth of the meshing gears and the meshing gears have different decelerations, the method comprising the steps: a. connecting a rotational power input to the gear train; b. disconnecting the rotational power input from the gear train so that the gears momentarily rotate freely of each other while the backlash between the gears is taken up because of their different decelerations; c. measuring the deceleration of one of the meshing gears while the backlash is being taken up; and d. determining the drag torque of the bearing supporting the one gear from the measured deceleration.

Claim 5

A method of determining the preload on preloaded bearings supporting two gears meshed in a gear train wherein there is a certain backlash between the teeth of these gears and wherein each of these gears has a drag torque exerted thereon by its supporting bearing and has a rotational inertia such that the ratio of the drag torque exerted on one gear by its supporting bearing to its rotational inertia is greater than the ratio for the other gear so that the one gear has a greater inherent deceleration than the other, the method comprising the steps: a. connecting a rotational power input to drive the gear having the greater inherent deceleration and thus drive the other gear; b. disconnecting the rotational power input so that the gear having the greater inherent deceleration momentarily rotates relative to the other to take up the backlash between the gears; c. measuring the deceleration of one of the gears while the backlash is being taken up; and e. determining the preload on the bearing supporting the gear whose deceleration was measured from the measured deceleration.

Claim 6

A method of determining the preload on preloaded bearings supporting two gears meshed in a gear train wherein there is a certain backlash between the teeth of these gears and wherein each of these gears has a drag torque exerted thereon by its supporting bearing and has a rotational inertia such that the ratio of the drag torque exerted on one gear by its supporting bearing to its rotational inertia is greater than the ratio for the other gear so that the one gear has a greater inherent deceleration than the other, the method comprising the steps: a. connecting a rotational power input to drive the gear having the greater inherent deceleration and thus drive the other gear; b. disconnecting the rotational power input so that the gear having the greater inherent deceleration momentarily rotates relative to the other to take up the backlash between the gears; c. measuring the deceleration of one of the gears while the backlash is being taken up; and e. determining the preload on the bearing supporting the gear whose deceleration was measured from the measured deceleration.

Claim 7

A method for determining the drag torque on preloaded bearings rotatably supporting a differential carrier assembly or a pinion gear in a differential housing, the carrier assembly including a ring gear enmeshed with the pinion gear and the ring gear and pinion gear comprising a portion of a gear train wherein there is a certain backlash between the teeth of these gears and wherein the pinion gear has a faster inherent deceleration than the carrier assembly, the method comprising the steps of: a. connecting deceleration measuring means to either the pinion gear or the carrier assembly for measuring the deceleration thereof when rotational power input is removed froM the pinion gear; b. connecting a rotational power input to drive the pinion gear and thus drive the differential carrier assembly through the ring gear; c. disconnecting the rotational power input from the pinion gear so that the pinion gear rotates relative to the ring gear to take up the backlash relative thereto because of the said faster inherent deceleration of the pinion gear; d. measuring by the deceleration measuring means the deceleration of said either one of the pinion gear or the carrier assembly during the momentary interval that the pinion gear takes up the backlash relative to the ring gear; and e. determining the drag torque of the bearings supporting either the pinion gear or the carrier assembly whose deceleration was measured from the measured deceleration.

Claim 8

A method for determining the drag torque on preloaded bearings rotatably supporting a differential carrier assembly or a pinion gear in a differential housing, the carrier assembly including a ring gear enmeshed with the pinion gear and the ring gear and pinion gear comprising a portion of a gear train wherein there is a certain backlash between the teeth of these gears and wherein the pinion gear has a faster inherent deceleration than the carrier assembly, the method comprising the steps of: a. connecting deceleration measuring means to either the pinion gear or the carrier assembly for measuring the deceleration thereof when rotational power input is removed froM the pinion gear; b. connecting a rotational power input to drive the pinion gear and thus drive the differential carrier assembly through the ring gear; c. disconnecting the rotational power input from the pinion gear so that the pinion gear rotates relative to the ring gear to take up the backlash relative thereto because of the said faster inherent deceleration of the pinion gear; d. measuring by the deceleration measuring means the deceleration of said either one of the pinion gear or the carrier assembly during the momentary interval that the pinion gear takes up the backlash relative to the ring gear; and e. determining the drag torque of the bearings supporting either the pinion gear or the carrier assembly whose deceleration was measured from the measured deceleration.

Claim 9

A method for determining the preload on side bearings seated in a housing of a differential assembly and rotatably supporting a carrier assembly carrying differential gears including a side gear, the differential housing having an axle shaft opening through which an axle shaft is subsequently drivingly connected with said side gear, said carrier assembly having a ring gear drivingly connected thereto and meshed with a pinion gear also rotatably supported in the differential housing by pinion bearings, the ring gear and the pinion gear having a certain backlash between the teeth thereof and the carrier assembly having a different rotational inertia about its axis than the pinion and the side bearings and pinion bearing exerting drag torques on the carrier assembly and pinion gear, the ratio of the drag torque exerted on the carrier assembly by said side bearing to its rotational inertia being greater than the ratio for the pinion gear so that the pinion gear may be induced to decelerate faster than the carrier assembly and take up the backlash relative thereto, the method comprising the steps of: a. drivingly connecting an input shaft of a deceleration measuring apparatus to the carrier assembly through said axle shaft opening in said differential housing before said axle shafts are connected with said side gear; b. connecting a rotational power input to said pinion to drive the pinion and therethrough the carrier assembly; c. disconnecting said rotational power input from said pinion so that the pinion rotates relative to the ring gear and takes up the backlash relative thereto because of the faster inherent deceleration of the pinion relative to the carrier assembly; d. measuring the deceleration of said input shaft of said deceleration measuring means to measure the deceleration of said carrier assembly; and e. determining drag torque of the side bearings supporting the carrier assembly from the measured deceleration.

Claim 10

A method for determining the preload on side bearings seated in a housing of a differential assembly and rotatably supporting a carrier assembly carrying differential gears including a side gear, the differential housing having an axle shaft opening through which an axle shaft is subsequently drivingly connected with said side gear, said carrier assembly having a ring gear drivingly connected thereto and meshed with a pinion gear also rotatably supported in the differential housing by pinion bearings, the ring gear and the pinion gear having a certain backlash between the teeth thereof and the carrier assembly having a different rotational inertia about its axis than the pinion and the side bearings and pinion bearing exerting drag torques on the carrier assembly and pinion gear, the ratio of the drag torque exerted on the carrier assembly by said side bearing to its rotational inertia being greater than the ratio for the pinion gear so that the pinion gear may be induced to decelerate faster than the carrier assembly and take up the backlash relative thereto, the method comprising the steps of: a. drivingly connecting an input shaft of a deceleration measuring apparatus to the carrier assembly through said axle shaft opening in said differential housing before said axle shafts are connected with said side gear; b. connecting a rotational power input to said pinion to drive the pinion and therethrough the carrier assembly; c. disconnecting said rotational power input from said pinion so that the pinion rotates relative to the ring gear and takes up the backlash relative thereto because of the faster inherent deceleration of the pinion relative to the carrier assembly; d. measuring the deceleration of said input shaft of said deceleration measuring means to measure the deceleration of said carrier assembly; and e. determining drag torque of the side bearings supporting the carrier assembly from the measured deceleration.