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US 4,286,476 AGranted
Rotary shaft control apparatus
OwnerBernard Stiffinventor
Life of this patent
Estimating the term…
Abstract
Apparatus for controlling a rotary shaft relative to a reference includes a strain wave drive having a specially shaped deformable ring gear for minimum stress. The wave generator part of the drive is normally caused to rotate with the input and output shafts connected to the drive's ring gears so that the two shafts are effectively keyed together. A tractive-type clutch assembly permits the wave generator to be rotated in one direction or the other relative to the deformable gear shaft so that the phase angle of the two shafts can be adjusted at a slow rate of speed dependent on the gear ratio of the drive. Also a tractive-type planetary assembly may be coupled between the clutch assembly and the wave generator so that the phase change may be accomplished at a plurality of speeds.
Claims19
Apparatus for controlling the phase or speed of a rotary shaft relative to another element comprising
- A. the strain wave drive including
- (1) a rigid ring gear,
- (2) a first shaft connected to the rigid gear,
- (3) a deformable ring gear,
- (4) a second shaft connected to the deformable gear,
- (5) a strain wave generator engaging the deformable gear, and
- (6) means for rotatively mounting the rigid gear and the deformable gear coaxially to one another so that said gears are in toothed engagement around at least parts of their peripheries;
- B. means for rotatively coupling the wave generator to the second one of said shafts so that said gears rotate in unison whereby said shafts are effectively rotatively keyed together, and
- C. means for dynamically rotating the wave generator through any selected angle in one direction or the other relative to said one shaft at a first rate so as to cause said one shaft to be advanced or retarded in phase relative to the other shaft at a second rate less than the first rate.
6 more elements
Apparatus for controlling the phase or speed of a rotary shaft relative to another element comprising
- A. a strain wave drive including
- (1) a rigid ring gear,
- (2) a first shaft connected to the rigid gear,
- (3) a second shaft,
- (4) a deformable ring gear connected to the second shaft and formed as an annular body of revolution, one end portion of the body in toothed engagement with the rigid gear being generally conical with a first selected diameter, the other end portion of the body connected to the second shaft being generally cylindrical and having a second selected diameter, and the portion of the body intermediate said two end portions having a third selected minimum diameter which is appreciably less than said first and second diameters;
- (5) a strain wave generator engaging the deformable gear, and
- (6) means for rotatively mounting the rigid gear and the deformable gear coaxially to one another so that said gears are in toothed engagement around at least part of their peripheries;
- B. means for rotatively coupling the wave generator to the second shaft so that said gears rotate in unison whereby said shafts are effectively rotatively keyed together, and
- C. means for selectively dynamically rotating the wave generator in one direction or the other relative to the second shaft at a first rate so as to cause said second shaft to be advanced or retarded in phase relative to said first shaft at a second rate less than the first rate.
6 more elements
Apparatus for controlling the phase or speed of a rotary shaft relative to another element comprising
- A. a strain wave drive including
- (1) a rigid ring gear,
- (2) a first shaft connected to the rigid gear,
- (3) a deformable ring gear,
- (4) a second shaft connected to the deformable gear,
- (5) a strain wave generator engaging the deformable gear, and
- (6) means for rotatively mounting the rigid gear and the deformable gear coaxially to one another so that said gears are in toothed engagement around at least parts of their peripheries;
- B. means for rotatively coupling the wave generator to one shaft so that said gears rotate in unison whereby said shafts are effectively rotatively keyed together, and
- C. means for selectively dynamically rotating the wave generator in one direction or the other relative to said one shaft at a first rate so as to cause the other shaft to be advanced or retarded in phase relative to said one shaft at a second rate less than the first rate, wherein said gears, first shaft, wave generator, mounting means, coupling means and rotating means are all mounted coaxially on and supported by the second shaft.
6 more elements
Apparatus for controlling the phase or speed of a rotary shaft relative to another element comprising
- A. a strain wave drive including
- (1) a rigid ring gear,
- (2) a first shaft connected to the rigid gear,
- (3) a deformable ring gear,
- (4) a second shaft connected to the deformable gear,
- (5) a strain wave generator engaging the deformable gear, and
- (6) means for rotatively mounting the rigid gear and the deformable gear coaxially to one another so that said gears are in toothed engagement around at least parts of their peripheries;
- B. means for rotatively coupling the wave generator to one of said shafts so that said gears rotate in unison whereby said shafts are effectively rotatively keyed together, said coupling means comprising
- (1) bearing means rotatively fixed to said one shaft,
- (2) means rotatably mounted on said one shaft and coacting with the bearing means, said rotatably mounted means being rotatively coupled to the wave generator, and
- (3) torque transmitting means coacting with the bearing means and the rotatably mounted means, and
- C. means for selectively dynamically rotating the wave generator in one direction or the other relative to said one shaft at a first rate so as to cause the other shaft to be advanced or retarded in phase relative to said one shaft at a second rate less than the first rate.
9 more elements
Apparatus for controlling the phase or speed of a rotary shaft relative to another element comprising
- A. a strain wave drive including
- (1) a rigid ring gear,
- (2) a first shaft connected to the rigid gear,
- (3) a deformable ring gear,
- (4) a second shaft connected to the deformable gear,
- (5) a strain wave generator engaging the deformable gear, and
- (6) means for rotatively mounting the rigid gear and the deformable gear coaxially to one another so that said gears are in toothed engagement around at least parts of their peripheries;
- B. means for rotatively coupling the wave generator to one of said shafts so that said gears rotate in unison whereby said shafts are effectively rotatively keyed together, said coupling means comprising speed changing planetary means acting between said one shaft and the wave generator so that the rotary speeds of said one shaft and wave generator have a selected ratio whereby said rate of advancement or retardation of the other shaft relative to said one shaft is a function of said speed ratio, and
- C. means for selectively dynamically rotating the wave generator in one direction or the other relative to said one shaft at a first rate so as to cause the other shaft to be advanced or retarded in phase relative to said one shaft at a second rate less than the first rate.
6 more elements
Dependencies are inferred from the claim text.