Planet pinion carrier assembly for ravigneaux gearset

Abstract

A gearset assembly includes a pinion carrier containing long pinions mutually spaced angularly about an axis and supported for rotation on the carrier, and short pinions, each short pinion supported for rotation on the carrier and meshing with a long pinion. A ring gear meshes with the long pinions. A first sun gear meshes with the short pinions, and a second sun gear meshes with the long pinions.

1. A gearset assembly comprising:
 a planet pinion carrier;    four long pinions having external gear teeth, mutually spaced angularly about an axis, and supported for rotation on the carrier; and    four short pinions having external gear teeth and supported for rotation on the carrier, each short pinion being spaced about the axis, located between two long pinions and meshing with two long pinions, each long pinion meshing with two short pinions.    
     
     
       2. The gearset assembly of  claim 1 , wherein the carrier further comprises a support including:
 a disc disposed substantially perpendicular to, and aligned with the axis, having a first set of axially directed, angularly spaced holes, and a second set of axially directed, angularly spaced holes;    posts radially spaced from the axis, extending axially from the disc toward the pinions, each post mutually angularly spaced about the axis; and    a pad secured to each post, axially spaced from the disc, extending radially toward the axis, and having a axially directed hole aligned with a hole of the second set of holes.    
     
     
       3. The gearset assembly of  claim 2 , wherein the carrier further comprises a drum aligned with the axis, secured to the pads and the posts, and including a radially outer cylindrical surface. 
     
     
       4. The gearset assembly of  claim 2 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon; and    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, and fitted within a hole on a pad.    
     
     
       5. The gearset assembly of  claim 2 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon; and    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, and fitted within a hole on a pad; and    a backing plate disposed substantially perpendicular to, and aligned with the axis, spaced axially from the disc, and having a third set of axially directed, angularly spaced holes, each hole of the third set being aligned with a hole of the first set, for supporting a pinion shaft of the first group on the backing plate.    
     
     
       6. The gearset assembly of  claim 2 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon;    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, fitted within a hole on a pad, passing axially through a hole of a pad, and including a length portion that extends axially away from the pad; and    a backing plate disposed substantially perpendicular to, and aligned with the axis, spaced axially from the disc, and having a third set of axially directed, angularly spaced holes, each hole of the third set of holes being aligned with a hole of the first set of holes, for supporting a pinion shaft of the first group on the backing plate, and having a fourth set of axially directed, angularly spaced holes, each hole of the fourth set being aligned with the length portion of a pinion shaft of the second group of pinion shafts.    
     
     
       7. The gearset assembly of  claim 2 , wherein the carrier further comprises a drum aligned with the axis, secured to the posts, and including a radially outer cylindrical surface; and
 the drum and support are formed of powered metal and are secured mutually by brazing.    
     
     
       8. A gearset assembly comprising:
 a pinion carrier;    a first sun gear including external gear teeth;    a second sun gear including external gear teeth;    a ring gear including internal gear teeth;    a planet pinion carrier;    long pinions having external gear teeth, each pinion mutually spaced angularly about an axis, supported for rotation on the carrier, and in meshing engagement with the first sun gear and the ring gear; and    short pinions having external gear teeth and supported for rotation on the carrier, each short pinion being spaced about the axis, located between two long pinions and meshing with two long pinions.    
     
     
       9. The gearset assembly of  claim 8 , wherein the carrier further comprises a support including:
 a disc disposed substantially perpendicular to, and aligned with the axis, having a first set of axially directed, angularly spaced holes, and a second set of axially directed, angularly spaced holes;    posts radially spaced from the axis, extending axially from the disc toward the pinions, each post mutually angularly spaced about the axis, the posts providing angularly spaced openings between angularly adjacent posts, each opening sized to permit at least a portion of the gear teeth of the long pinions to engage the ring gear; and    a pad secured to each post, axially spaced from the disc, extending radially toward the axis, and having of two axially directed holes, aligned with a hole of the second set of holes.    
     
     
       10. The gearset assembly of  claim 9 , wherein the carrier further comprises a drum aligned with the axis, secured to the pads and the posts, and including a radially outer cylindrical surface. 
     
     
       11. The gearset assembly of  claim 9 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon; and    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, and fitted within a hole on a pad.    
     
     
       12. The gearset assembly of  claim 9 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon; and    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, and fitted within a hole on a pad;    a backing plate disposed substantially perpendicular to, and aligned with the axis, spaced axially from the disc, and having a third set of axially directed, angularly spaced holes, each hole of the third set being aligned with a hole of the first set, for supporting a pinion shaft of the first group on the backing plate.    
     
     
       13. The gearset assembly of  claim 9 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon;    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, fitted within a hole on a pad, passing axially through a hole of a pad, and including a length portion that extends axially away from the pad; and    a backing plate disposed substantially perpendicular to, and aligned with the axis, spaced axially from the disc, and having a third set of axially directed, angularly spaced holes, each hole of the third set of holes being aligned with a hole of the first set of holes, for supporting a pinion shaft of the first group on the backing plate, and having a fourth set of axially directed, angularly spaced holes, each hole of the fourth set being aligned with the length portion of a pinion shaft of the second group of pinion shafts.    
     
     
       14. The gearset assembly of  claim 9 , wherein the carrier further comprises a drum aligned with the axis, secured to the posts, and including a radially outer cylindrical surface; and
 the drum and support are formed of powered metal and are secured mutually by brazing.    
     
     
       15. A gearset assembly comprising:
 a pinion carrier including 
 a disc disposed substantially perpendicular to, and aligned with the axis, having a first set of axially directed, angularly spaced holes, and a second set of axially directed, angularly spaced holes;  
 posts radially spaced from the axis, extending axially from the disc toward the pinions, each post mutually spaced angularly about the axis; and  
 a pad secured to each post, axially spaced from the disc, extending radially toward the axis, and having of two axially directed holes, aligned with a hole of the second set, the pads providing axially directed access spaces, each access space being aligned with a hole of the first set of holes;  
   long pinions having external gear teeth, each pinion mutually spaced angularly about an axis, supported for rotation on the carrier, and located in an access space; and    short pinions having external gear teeth and supported for rotation on the carrier, each short pinion being spaced about the axis, located between two long pinions and meshing with two long pinions.    
     
     
       16. The gearset assembly of  claim 15 , wherein the carrier further comprises a drum aligned with the axis, secured to the pads and the posts, and including a radially outer cylindrical surface. 
     
     
       17. The gearset assembly of  claim 15 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon; and    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, and fitted within a hole on a pad.    
     
     
       18. The gearset assembly of  claim 15 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon; and    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, and fitted within a hole on a pad;    a backing plate disposed substantially perpendicular to, and aligned with the axis, spaced axially from the disc, and having a third set of axially directed, angularly spaced holes, each hole of the third set being aligned with a hole of the first set, for supporting a pinion shaft of the first group on the backing plate.    
     
     
       19. The gearset assembly of  claim 15 , further comprising:
 a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a long pinion for rotation thereon;    a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a short pinion for rotation thereon, fitted within a hole on a pad, passing axially through a hole of a pad, and including a length portion that extends axially away from the pad; and    a backing plate disposed substantially perpendicular to, and aligned with the axis, spaced axially from the disc, and having a third set of axially directed, angularly spaced holes, each hole of the third set of holes being aligned with a hole of the first set of holes, for supporting a pinion shaft of the first group on the backing plate, and having a fourth set of axially directed, angularly spaced holes, each hole of the fourth set being aligned with the length portion of a pinion shaft of the second group of pinion shafts.    
     
     
       20. The gearset assembly of  claim 15 , wherein the carrier further comprises a drum aligned with the axis, secured to the posts, and including a radially outer cylindrical surface; and
 the drum and support are formed of powered metal and are secured mutually by brazing.    
     
     
       21. A gearset assembly comprising:
 a planet pinion carrier;    four long pinions mutually spaced angularly about an axis, and supported for rotation on the carrier; and    four short pinions supported for rotation on the carrier, each short pinion being spaced about the axis, located between two long pinions and meshing with two long pinions.    
     
     
       22. The gearset assembly of  claim 21 , further comprising
 a first sun gear in meshing engagement with the short pinions; and    a second sun gear in meshing engagement with the long pinions.    
     
     
       23. The gearset assembly of  claim 21 , further comprising
 a ring gear in meshing engagement with the long pinions;    a first sun gear in meshing engagement with the short pinions; and    a second sun gear in meshing engagement with the long pinions.    
     
     
       24. A gearset assembly comprising:
 a planet pinion carrier;    five long pinions mutually spaced angularly about an axis, and supported for rotation on the carrier; and    five short pinions supported for rotation on the carrier, each short pinion being spaced about the axis, located between two long pinions and meshing with two long pinions.    
     
     
       25. The gearset assembly of  claim 24 , further comprising
 a first sun gear in meshing engagement with the short pinions; and    a second sun gear in meshing engagement with the long pinions.    
     
     
       26. The gearset assembly of  claim 24 , further comprising
 a ring gear in meshing engagement with the long pinions;    a first sun gear in meshing engagement with the short pinions; and    a second sun gear in meshing engagement with the long pinions.    
     
     
       27. A gearset assembly comprising:
   a sun gear having an axis,        a planet pinion carrier;        a pair of first pinions having external gear teeth, spaced angularly about the axis, supported for rotation on the carrier and meshing with the sun gear;        a second pinion having external gear teeth, supported for rotation on the carrier and meshing with two of the first pinions,        wherein a phase error of the gearset, being a function of the number of teeth on reference gears comprising the sun gear, the first pinions and the second pinion, and, for each of the reference gears, an angle between each of two base circle radii and a common tangent to the base circle of the subject reference gear and the base circle of each of the two reference gears meshing with the subject reference gear, is substantially zero.     
     
     
       28. The gearset assembly of  claim 27 , wherein:
   the sun gear, the pair of first pinions, and the second pinion are arranged symmetrically about a line connecting a center of said second pinion and a center of the sun gear.     
     
     
       29. The gearset assembly of  claim 27 , further comprising:
   a second pair of first pinions having external gear teeth, spaced angularly about the axis, supported for rotation on the carrier and meshing with the sun gear;        a second sun gear concentric with the axis; and        wherein said at least one second pinion comprises four second pinions having external gear teeth, supported for rotation on the carrier, each second pinion meshing with two of the first pinions and the second sun gear, the sun gear, one pair of first pinions, and said one second pinion are arranged symmetrically about a line connecting a center of said second pinion and a center of the sun gear.     
     
     
       30. The gearset assembly of  claim 27 , further comprising:
   a second sun gear concentric with the axis; and        wherein each of the first pinions is axially longer than the second pinions and meshes with the second sun gear.     
     
     
       31. The gearset assembly of  claim 27 , further comprising:
   a second sun gear concentric with the axis; and        wherein each of the second pinions is axially longer than the first pinions and meshes with the second sun gear.     
     
     
       32. The gearset assembly of  claim 27  further comprising:
   a ring gear having internal teeth; and        wherein the second pinions mesh with the ring gear.     
     
     
       33. The gearset assembly of  claim 27  further comprising:
   a ring gear having internal teeth; and        wherein the first pinions mesh with the ring gear.     
     
     
       34. The gearset assembly of  claim 27 , wherein the carrier further comprises a support including:
   a disc disposed substantially perpendicular to, and aligned with the axis, having a first set of axially directed, angularly spaced holes, and a second set of axially directed, angularly spaced holes;        posts radially spaced from the axis, extending axially from the disc toward the pinions, each post mutually angularly spaced about the axis; and        a pad secured to each post, axially spaced from the disc, extending radially toward the axis, and having an axially directed hole aligned with a hole of the second set of holes.     
     
     
       35. The gearset assembly of  claim 34 , further comprising:
   a first group of pinion shafts fitted within a hole of the first set of holes for support on the disc, each pinion shaft of the first group supporting a first pinion for rotation thereon; and        a second group of pinion shafts fitted within a hole of the second set of holes for support on the disc, each pinion shaft of the second group supporting a second pinion for rotation thereon, and fitted within a hole on a pad.     
     
     
       36. A gearset assembly comprising:
   a sun gear having an axis,        a planet pinion carrier;        four first pinions having external gear teeth, spaced angularly about the axis, supported for rotation on the carrier and meshing with the sun gear; and        four second pinions having external gear teeth, supported for rotation on the carrier, each second pinion meshing with two of the first pinions,        wherein a phase error of the gearset, being a function of the number of teeth on reference gears comprising the sun gear, the first pinions and the second pinions, and, for each of the reference gears, an angle between each of two base circle radii and a common tangent to the base circle of the subject reference gear and the base circle of each of the two reference gears meshing with the subject reference gear, is substantially zero.     
     
     
       37. The gear set of  claim 36  wherein the first pinions are spaced mutually at equal angular increments about the axis, and the second pinions are spaced mutually at equal angular increments about the axis. 
     
     
       38. A gearset assembly comprising:
   a first sun gear having an axis,        a second sun gear concentric with the axis;        a planet pinion carrier;        four first pinions having external gear teeth, spaced angularly about the axis, supported for rotation on the carrier and meshing with the first sun gear; and        four second pinions having external gear teeth, supported for rotation on the carrier, each second pinion meshing with two of the first pinions and the second sun gear,        wherein a phase error of the gearset, being a function of the number of teeth on reference gears comprising the sun gear, the first pinions and the second pinions, and, for each of the reference gears, an angle between each of two base circle radii and a common tangent to the base circle of the subject reference gear and the base circle of each of the two reference gears meshing with the subject reference gear, is substantially zero.     
     
     
       39. The gearset assembly of  claim 38 , wherein:
   the sun gear, a pair of the first pinions, and one of the second pinion are arranged symmetrically about a center of the sun gear.     
     
     
       40. The gearset assembly of  claim 38 , further comprising:
   a second pair of first pinions having external gear teeth, spaced angularly about the axis, supported for rotation on the carrier and meshing with the sun gear;        a second sun gear concentric with the axis; and        wherein said at least one second pinion comprises four second pinions having external gear teeth, supported for rotation on the carrier, each second pinion meshing with two of the first pinions and the second sun gear, the sun gear, one pair of first pinions, and said one second pinion are arranged symmetrically about a center of the sun gear.     
     
     
       41. The gearset assembly of  claim 38 , further comprising:
   a second sun gear concentric with the axis; and        wherein each of the first pinions is axially longer than the second pinions and meshes with the second sun gear.     
     
     
       42. The gearset assembly of  claim 38 , further comprising:
   a second sun gear concentric with the axis; and        wherein each of the second pinions is axially longer than the first pinions and meshes with the second sun gear.     
     
     
       43. The gearset assembly of  claim 38  further comprising:
   a ring gear having internal teeth; and        wherein the second pinions mesh with the ring gear.     
     
     
       44. The gearset assembly of  claim 38  further comprising:
   a ring gear having internal teeth; and        wherein the first pinions mesh with the ring gear.     
     
     
       45. A method of determining parameters of a gearset assembly that includes a sun gear having an axis; a set of first pinions, mutually spaced angularly about the axis and meshing with the sun gear; and a set of second pinions, each second pinion being spaced about the axis, located between and meshing with two first pinions, each first pinion being located between and meshing with two second pinions, the method comprising the steps of:
   determining the number of teeth for the sun gear, the first pinions and the second pinions that will enable the gearset to produce at least one desired gear ratio;        determining gearset parameters of reference gears that include the first sun gear, a pair of the first pinions and one of the second pinions that meshes with the pair of first pinions;        determining for each of the reference gears an angle between each of two base circle radii and a common tangent to the base circle of the subject reference gear and the base circle of each of the two reference gears meshing with the subject reference gear;        determining a phase error of the reference gears as a function of the number of teeth on the reference gears and the determined angles; and        adjusting at least one parameter of the gearset such that the phase error is substantially zero.     
     
     
       46. The method of  claim 45  further comprising the step of:
   adjusting a center distance that extends between at least two of the reference gears such that the phase error is substantially zero.