Planetary gear carrier with compliance

1. A planetary gear assembly ( 30 ) comprising: at least one ring gear ( 32 , 34 ), a sun gear ( 28 ), and a plurality of rotatable planetary gears ( 36 a , 36 b , 36 c ) radially interposed between the at least one ring gear ( 32 , 34 ) and the sun gear ( 28 ), each of the plurality of planetary gears ( 36 a , 36 b , 36 c ) having a separate spaced rotational axis with respect to other planetary gears ( 36 a , 36 b , 36 c );

a compliant planetary gear carrier ( 40 , 140 ) supporting the plurality of planetary gears ( 36 a , 36 b , 36 c ) for rotation and connected between each rotational axis of the plurality of planetary gears ( 36 a , 36 b , 36 c ), the compliant planetary gear carrier ( 40 , 140 ) having at least one biasing member ( 48 , 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) connected between the rotational axes of two of the plurality of planetary gears ( 36 a , 36 b , 36 c ) and at least a portion of the compliant planetary gear carrier ( 40 , 140 ) pivoting about a rotational axis of one of the plurality of planetary gears ( 36 a , 36 b , 36 c ) allowing variance of a distance between the axes of at least two of the plurality of planetary gears ( 36 a , 36 b , 36 c ) compensating for mechanical tolerances of the at least one ring gear ( 32 , 34 ).

2. The planetary gear assembly ( 30 ) of claim 1 , wherein the at least one ring gear ( 32 , 34 ) further comprises a split ring gear including a drive-side ring gear portion ( 32 ) for driven rotation by a first shaft and an output-side ring gear portion ( 34 ) located concentric with respect to the sun gear ( 28 ) for driving connection to a second shaft ( 22 ), the output-side ring gear ( 34 ) having a different number of teeth with respect to the drive-side ring gear ( 32 ) by a value corresponding to a multiple of the number of planetary gears ( 36 a , 36 b , 36 c ) to provide tooth alignment at an engagement position of each of the planetary gears ( 36 a , 36 b , 36 c ).

3. The planetary gear assembly ( 30 ) of claim 1 , wherein the compliant planetary gear carrier ( 40 ) further comprises:

a first rigid link ( 42 ) and a second rigid link ( 44 ) connected for pivoting movement with respect to the rotational axis of a first planetary gear ( 36 a ), the first rigid link ( 42 ) connected between a first rotational axis of the first planetary gear ( 36 a ) and a second rotational axis of a second planetary gear ( 36 b ), the first rigid link ( 42 ) supporting the second planetary gear ( 36 b ) for slight movement with respect to the first planetary gear ( 36 a ), the second rigid link ( 44 ) connected between the first rotational axis of the first planetary gear ( 36 a ) and a third rotational axis of a third planetary gear ( 36 c ), the second rigid link ( 44 ) supporting the third planetary gear ( 36 c ) for slight movement with respect to the first planetary gear ( 36 a ); and, wherein the at least one biasing member comprises a spring ( 48 ) engageable between the first rigid link ( 42 ) and the second rigid link ( 44 ) allowing pivoting movement of the first rigid link ( 42 ) and the second rigid link ( 44 ) with respect to one another about the first rotational axis of the first planetary gear ( 36 a ).

4. The planetary gear assembly ( 30 ) of claim 1 , wherein the compliant planetary gear carrier ( 40 ) further comprises:

a first rigid link ( 42 ) and a second rigid link ( 44 ) connected for pivoting movement with respect to the rotational axis of a first planetary gear ( 36 a ), the first rigid link ( 42 ) connected between a first rotational axis of the first planetary gear ( 36 a ) and a second rotational axis of a second planetary gear ( 36 b ), the first rigid link ( 42 ) supporting the second planetary gear ( 36 b ) for slight movement with respect to the first planetary gear ( 36 a ), the second rigid link ( 44 ) connected between the first rotational axis of the first planetary gear ( 36 a ) and a third rotational axis of a third planetary gear ( 36 c ), the second rigid link ( 44 ) supporting the third planetary gear ( 36 c ) for slight movement with respect to the first planetary gear ( 36 a ); and, wherein the at least one biasing member comprises a jack screw ( 50 ) engageable between the first rigid link ( 42 ) and the second rigid link ( 44 ), the jack screw ( 50 ) adjustable during assembly of the planetary gear assembly ( 30 ) and fixed after the plurality of planetary gears ( 36 a , 36 b , 36 c ) are assembled for meshing engagement between the at least one ring gear ( 32 , 34 ) and the sun gear ( 28 ).

5. The planetary gear assembly ( 30 ) of claim 1 , wherein the at least one biasing member comprises:

a plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ), each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) connected between the rotational axes of two of the plurality of planetary gears ( 36 a , 36 b , 36 c ).

6. The planetary gear assembly ( 30 ) of claim 5 , wherein the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) further comprises:

a pair of first blade spring links ( 142 a , 142 b ) supporting a first planetary gear ( 36 a ) and a second planetary gear ( 36 b ) interposed between the pair of first blade spring links ( 142 a , 142 b ), the first and second planetary gears ( 36 a , 36 b ) pivotally connected for rotation about separate spaced rotational axes between a first rotational axis of the first planetary gear ( 36 a ) and a second rotational axis of the second planetary gear ( 36 b );

a pair of second blade spring links ( 144 a , 144 b ) supporting the second planetary gear ( 36 b ) and a third planetary gear ( 36 c ) interposed between the pair of second blades spring links ( 144 a , 144 b ), the second and third planetary gears ( 36 b , 36 c ) pivotally connected for rotation about separate spaced rotational axes between the second rotational axis of the second planetary gear ( 36 b ) and a third rotational axis of the third planetary gear ( 36 c ); and

a pair of third blade spring links ( 146 a , 146 b ) supporting the first planetary gear ( 36 a ) and the third planetary gear ( 36 c ) interposed between the pair of third blade spring links ( 146 a , 146 b ), the first and third planetary gears ( 36 a , 36 c ) pivotally connected for rotation about separate spaced rotational axes between the first rotational axis of the first planetary gear ( 36 a ) and the third rotational axis of the third planetary gear ( 36 c ).

7. The planetary gear assembly ( 30 ) of claim 6 further comprising:

a plurality of shoulder pins ( 52 a , 52 b , 52 c ) corresponding in number to the plurality of planetary gears ( 36 a , 36 b , 36 c ), each of the plurality of shoulder pins ( 52 a , 52 b , 52 c ) located along the rotational axis of the corresponding one of the plurality of planetary gears ( 36 a , 36 b , 36 c ), each of the plurality of planetary gears ( 36 a , 36 b , 36 c ) mounted for rotation on a corresponding one of the plurality of shoulder pins ( 52 a , 52 b , 52 c ), each of the plurality of blade springs ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) mounted to the corresponding one of the plurality of shoulder pins ( 52 a , 52 b , 52 c ); and

a plurality of crimp rings ( 54 a , 54 b , 54 c , 54 d , 54 e , 54 f ) corresponding to the plurality of shoulder pins ( 52 a , 52 b , 52 c ), each of the plurality of crimp rings ( 54 a , 54 b , 54 c , 54 d , 54 e , 54 f ) mounted at ends of the corresponding one of the plurality of shoulder pins ( 52 a , 52 b , 52 c ), the plurality of crimp rings ( 54 a , 54 b , 54 c , 54 d , 54 e , 54 f ) fastening ends of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) to the corresponding plurality of shoulder pins ( 52 a , 52 b , 52 c ).

8. The planetary gear assembly ( 30 ) of claim 5 , wherein each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) further comprises:

a flexible portion ( 152 a , 152 b , 152 c , 152 d , 152 e , 152 f ) extending between fastened opposite ends of each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ), the flexible portions ( 152 a , 152 b , 152 c , 152 d , 152 e , 152 f ) of each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) normally biased toward a planar shape, the flexible portions ( 152 a , 152 b , 152 c , 152 d , 152 e , 152 f ) flexibly urged axially inwardly to decrease an equidistant dimension between the first, second, and third rotational axes during assembly of the planetary gear assembly ( 30 ) and flexibly springing back to return to the equidistant dimension between the first, second and third rotational axes after assembly.

9. A planetary gear assembly ( 30 ) in an electric camshaft phaser ( 20 ) comprising:

a sun gear ( 28 ) located along a longitudinal axis for driven rotation by a rotatable electric motor ( 24 );

a split ring gear including a drive-side ring gear portion ( 32 ) for driven rotation by an engine crankshaft through an endless loop power transmission member and an output-side ring gear portion ( 34 ), the output-side ring gear portion ( 34 ) located concentric with respect to the sun gear ( 28 ) for driving connection to a camshaft ( 22 ), the electric motor ( 24 ) rotatable at a speed equal with respect to the output-side ring gear ( 32 ) to maintain a constant phase position of the camshaft with respect to the crankshaft, the electric motor ( 24 ) rotatable at a varying speed with respect to the output-side ring gear ( 32 ) during a cam phase change of the camshaft with respect to the crankshaft;

a plurality of rotatable planetary gears ( 36 a , 36 b , 36 c ) radially interposed between the sun gear and the split ring gear including the drive-side ring gear portion ( 32 ) and the output-side ring gear portion ( 34 ), each of the plurality of planetary gears ( 36 a , 36 b , 36 c ) having a separate spaced rotational axis with respect to other planetary gears ( 36 a , 36 b , 36 c ), the output-side ring gear portion ( 34 ) having a different number of teeth with respect to the drive-side ring gear portion ( 32 ) by a value corresponding to a multiple of the number of planetary gears ( 36 a , 36 b , 36 c ); and

a compliant planetary gear carrier ( 40 , 140 ) supporting the plurality of planetary gears ( 36 a , 36 b , 36 c ) for rotation, at least a portion of the compliant planetary gear carrier ( 40 , 140 ) pivots about a rotational axis of at least one of the planetary gears ( 36 a , 36 b , 36 c ), the compliant planetary gear carrier ( 40 , 140 ) allowing variance of a normally equidistant distance between the separate spaced rotational axes of at least two of the plurality of planetary gears ( 36 a , 36 b , 36 c ) to selectively compensate for mechanical tolerances of the drive-side ring gear portion ( 32 ) and the output-side ring gear portion ( 34 ) of the split ring gear.

10. The planetary gear assembly ( 30 ) of claim 9 , wherein the compliant planetary gear carrier ( 40 ) further comprises:

a first rigid link ( 42 ) and a second rigid link ( 44 ) connected for pivoting movement with respect to a first rotational axis of a first planetary gear ( 36 a ), the first rigid link ( 42 ) connected between the first rotational axis of the first planetary gear ( 36 a ) and a second rotational axis of a second planetary gear ( 36 b ), the first rigid link ( 42 ) supporting the second planetary gear ( 36 b ) for slight movement with respect to the first planetary gear ( 36 a ), the second rigid link ( 44 ) connected between the first rotational axis of the first planetary gear ( 36 a ) and a third rotational axis of a third planetary gear ( 36 c ), the second rigid link ( 44 ) supporting the third planetary gear ( 36 c ) for slight movement with respect to the first planetary gear ( 36 a ); and

at least one spring ( 48 ) engageable between the first rigid link ( 42 ) and the second rigid link ( 44 ) allowing pivoting movement of the first rigid link ( 42 ) and the second rigid link ( 44 ) with respect to one another about the first rotational axis of the first planetary gear ( 36 a ).

11. The planetary gear assembly ( 30 ) of claim 9 , wherein the compliant planetary gear carrier ( 140 ) further comprises:

a plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ), each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) connected between the rotational axes of two of the plurality of planetary gears ( 36 a , 36 b , 36 c ), the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) including:

a pair of first blade spring links ( 142 a , 142 b ) pivotally connected between the first rotational axis of the first planetary gear ( 36 a ) and the second rotational axis of the second planetary gear ( 36 b );

a pair of second blade spring links ( 144 a , 144 b ) pivotally connected between the second rotational axis of the second planetary gear ( 36 b ) and the third rotational axis of the third planetary gear ( 36 c ); and

a pair of third blade spring links ( 146 a , 146 b ) pivotally connected between the third rotational axis of the third planetary gear ( 36 c ) and the first rotational axis of the first planetary gear ( 36 a ), the first planetary gear ( 36 a ) interposed between the pair of first blade spring links ( 142 a , 142 b ) and the pair of third blade spring links ( 146 a , 146 b ), the second planetary gear ( 36 b ) interposed between the pair of second blade spring links ( 144 a , 144 b ) and the pair of first blade spring links ( 142 a , 142 b ), the third planetary gear ( 36 c ) interposed between the pair of second blade spring links ( 144 a , 144 b ) and the pair of third blade spring links ( 146 a , 146 b ).

12. The planetary gear assembly ( 30 ) of claim 11 further comprising: a plurality of crimp rings ( 54 a , 54 b , 54 c , 54 d , 54 e , 54 f ) corresponding to a plurality of shoulder pins ( 52 a , 52 b , 52 c ), each of the plurality of crimp rings ( 54 a , 54 b , 54 c , 54 d , 54 e , 54 f ) mounted at ends of the corresponding one of the plurality of shoulder pins ( 52 a , 52 b , 52 c ), the plurality of crimp rings ( 54 a , 54 b , 54 c , 54 d , 54 e , 54 f ) fastening ends of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) to the corresponding plurality of shoulder pins ( 52 a , 52 b , 52 c ).

13. The planetary gear assembly ( 30 ) of claim 11 , wherein each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) further comprises:

a flexible portion ( 152 a , 152 b , 152 c , 152 d , 152 e , 152 f ) extending between fastened opposite ends of each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ), the flexible portions ( 152 a , 152 b , 152 c , 152 d , 152 e , 152 f ) of each of the blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) normally biased toward a planar shape maintaining a spring-biased equidistant dimension between separate spaced first, second, and third rotational axes, the flexible portions ( 152 a , 152 b , 152 c , 152 d , 152 e , 1520 flexibly urged inwardly towards one another during assembly of the planetary gear assembly ( 30 ) reducing the equidistant dimension between the separate spaced first, second, and third rotational axes, and flexibly rebounding to return to the planar shape reestablishing the spring-biased equidistant dimension between spaced separate first, second and third rotational axes after assembly.

14. A method for assembling a planetary gear assembly ( 30 ) in an electric camshaft phaser ( 20 ) for dynamically adjusting a rotational relationship of a camshaft ( 22 ) of an internal combustion engine with respect to an engine crankshaft, the camshaft phaser ( 20 ) including a planetary gear assembly ( 30 ) having a split ring gear including a drive-side ring gear portion ( 32 ) operably driven by the crankshaft through an endless loop power transmission member and an output-side ring gear portion ( 34 ), a plurality of planetary gears ( 36 a , 36 b , 36 c ), and a sun gear ( 28 ) centrally located and operably driven by an electric motor ( 24 ), each of the plurality of planetary gears ( 36 a , 36 b , 36 c ) having a rotational axis, the method comprising:

mounting the split ring gear including the drive-side ring gear portion ( 32 ) and the output-side ring gear portion ( 34 ) concentrically with respect to the sun gear ( 28 ), the output-side ring gear portion ( 34 ) for connection to the camshaft ( 22 ), the output-side ring gear portion ( 34 ) having a different number of teeth with respect to the drive-side ring gear portion ( 32 ) by a value corresponding to a multiple of the number of planetary gears ( 36 a , 36 b , 36 c ), the electric motor ( 24 ) rotatable at a speed equal with respect to the output-side ring gear ( 32 ) to maintain a constant phase position of the camshaft with respect to the crankshaft, the electric motor ( 24 ) rotatable at a varying speed with respect to the output-side ring gear ( 32 ) during a cam phase change of the camshaft with respect to the crankshaft;

positioning a compliant planetary gear carrier ( 40 , 140 ) supporting the plurality of planetary gears ( 36 a , 36 b , 36 c ) for rotation, the compliant planetary gear carrier ( 40 , 140 ) allowing variance of a normally equidistant distance between the rotational axes of at least two of the plurality of planetary gears ( 36 a , 36 b , 36 c ) to selectively compensate for mechanical tolerances of the split ring gear including the drive-side ring gear portion ( 32 ) and the output-side ring gear portion ( 34 ); and

meshingly interposing the plurality of rotatable planetary gears ( 36 a , 36 b , 36 c ) between the sun gear ( 28 ) and the split ring gear including the output-side ring gear portion ( 34 ) and the drive-side ring gear portion ( 32 ).

15. The method of claim 14 further comprising:

mounting the plurality of planetary gears ( 36 a , 36 b , 36 c ) to a corresponding plurality of shoulder pins ( 52 a , 52 b , 52 c ), each of the plurality of shoulder pins ( 52 a , 52 b , 52 c ) located along the rotational axis of one of the plurality of planetary gears ( 36 a , 36 b , 36 c );

pivotally connecting a plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) between each of the plurality of planetary gears ( 36 a , 36 b , 36 c );

fastening ends of each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) to the corresponding shoulder pins ( 52 a , 52 b , 52 c ), each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) having a flexible portion extending between the fastened ends, the flexible portions normally biased axially outwardly with respect to one another;

pressing the flexible portions ( 152 a , 152 b , 152 c , 152 d , 152 e , 152 f ) of the blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) inwardly towards one another while interposing the plurality of rotatable planetary gears ( 36 a , 36 b , 36 c ) between the sun gear ( 28 ) and the split ring gear including the drive-side ring gear portion ( 32 ) and the output-side ring gear portion ( 34 ); and

releasing the flexible portion ( 152 a , 152 b , 152 c , 152 d , 152 e , 152 f ) of each of the plurality of blade spring links ( 142 a , 142 b , 144 a , 144 b , 146 a , 146 b ) after interposing the plurality of planetary gears ( 36 a , 36 b , 36 c ) between the sun gear ( 28 ) and the split ring gear including the drive-side ring gear portion ( 32 ) and the output-side ring gear portion ( 34 ).