Synchronously shiftable dual range planetary transmission with coaxial input shafts

Claim 2

A power transmission for use with power input means for imparting rotary drive to the transmission, comprising in combination: an input quill shaft and an inner shaft coaxial therewithin in which said inner shaft projects beyond said quill shaft at either end thereof; low speed planetary gear means and high speed planetary gear means each centered about said input shafts and including sun gear input means connected to said quill shaft for continuously imparting one input path to both of said planetary gear means; said low speed planetary gear means also including thirdelement gear means and planet gear means for reacting between said sun gear input means and the said third-element gear means and said high speed planetary gear means also including thirdelement gear means and planet gear means for reacting between said sun gear input means and the third-element gear means of said high speed planetary gear means; an output shaft aligned with but disposed beyond said input shafts; one of the two gear means constituted by said third-element gear means of said high speed planetary gear means and said planet gear means of said high speed planetary gear means being connected to said output shaft and to said planet gear means of said low speed planetary gear means whereby said output shaft is capable of connection to said sun gear input means through either of said low speed and said high speed planetary gear means and a continuous drive coupling is effected between said low speed and said high speed planetary gear means; a hydrostatic drive unit comprising a driving member mechanically connected to said power input means and a rotatable driven member connected to said input quill shaft and including means for infinitely varying the rotational speed of said driven member between first and second maximum speeds which are of opposite rotational sense with respect to each other and of maximum sense with respect to the rotational speed of said driving member; brake means for selectively braking said third-element gear means of said low speed planetary gear means to prevent rotation thereof and establish low speed drive; and clutch means for selectively coupling said power input means to the other of said two gear means of the high speed planetary gear means through said inner input shaft to establish high speed drive; and the gear ratios of said low speed and said high speed planetary gear means being such that as the speed of said output shaft is increasing in low speed range and said driven member of the hydrostatic unit attains said first maximum speed, said clutch means may be synchronously engaged while said brake means is disengaged under substantially no load, and as the speed of said output shaft is decreasing in high speed range and said driven member attains said first maximum speed, said clutch means may be synchronously disengaged while said brake means is engaged under substantially no load.

Claim 3

A power transmission as defined in claim 1 wherein said planet gear means of the high speed planetary gear means is connected to said output shaft and to the planet gear means of said low speed planetary gear means and said third-element gear means of said high speed planetary is selectively coupled to said inner shaft by said clutch means.

Claim 4

A power transmission as defined in claim 1 wherein said third-element gear means of said high speed planetary gear means is connected to said output shaft and to the planet gear means of said low speed planetary gear means and said planet gear means of said high speed planetary gear means is selectively coupled to said inner shaft by said clutch means.

Claim 5

In a drive train of the type including power input means; an output shaft; a pair of input shafts one of which is connected directly to the power input means; hydrostatic drive means connecting the power input means to the other of said input shafts; a pair of in-line planetary gear means having a drive interconnection therebetween, one of said planetary gear means having a single input from said one input shaft to drive the output shaft in low speed mode while effecting torque multiplication through such low speed planetary gear means, and the other planetary gear means having inputs from both input shafts to drive said output shaft in high speed mode by differential dual-input power to such high speed planetary gear means; said hydrostatic drive means including means for effecting relatively reverse directions of rotation of said one input shaft whereby in low speed mode both forward and reverse direction drive is possible at the output shaft and whereby in high speed mode the range thereof is extended by coupling said one input shaft through a progressively changing rotational speed program from a first maximum rotational speed in one direction of rotation to a second maximum rotational speed in the opposite direction of rotation; the ratios of said planetary gears means being such that synchronous shifting between said low and high speed modes is effected at said first maximum speed of rotation of one input shaft, the improvement wherein: said one input shaft is a quill shaft and said other input shaft is coaxial with said quill shaft and projects completely through said quill shaft for connection at its opposite ends respectively with said power input means and with said high speed planetary gear means; said low speed planetary gear means and said high speed planetary gear means each being centered about said input shafts and including sun gear input means connected to said quill shaft for continuously imparting one input path to both of said planetary gear means; said low speed planetary gear means also including third-element gear means and planet gear means for reacting between said sun gear input means and said third-element gear means and said high speed planetary gear means also including third-element gear means and planet gear means for reacting between said sun gear input means and the third-element gear means of said high speed planetary gear means; said output shaft being aligned with but disposed beyond said input shafts and said high speed planetary gear means being disposed closest to said output shaft; one of the two gear means constituted by said third-element gear means of said high speed planetary gear means and said second planet gear means of said high speed planetary gear means being connected to said output shaft and to said planet gear means of said low speed planetary gear means whereby said output shaft is capable of connection to said sun gear input means through either of said low and high speed planetary gear means and a continuous drive coupling is effected between said low speed and said high speed planetary gear means; said hydrostatic drive unit comprising a driving member mechanically connected to said power input means and a rotatable driven member connected to said quill shaft and including means for infinitely varying the rotational speed of said driven member between said first and said second maximum speeds; brake means for selectively braking said third-element gear means of said low speed planetary gear means to prevent rotation thereof and establish low speed drive; and clutch means for selectively coupling said power input means to the other of said two gear means of the high speed planetary gear means through said other input shaft to establish high speed drive.

Claim 6

In a drive train of the type including power input means; an output shaft; a pair of input shafts one of which is connected directly to the power input means; hydrostatic drive means connecting the power input means to the other of said input shafts; a pair of in-line planetary gear means having a drive interconnection therebetween, one of said planetary gear means having a single input from said one input shaft to drive the output shaft in low speed mode while effecting torque multiplication through such low speed planetary gear means, and the other planetary gear means having inputs from both input shafts to drive said output shaft in high speed mode by differential dual-input power to such high speed planetary gear means; said hydrostatic drive means including means for effecting relatively reverse directions of rotation of said one input shaft whereby in low speed mode both forward and reverse direction drive is possible at the output shaft and whereby in high speed mode the range thereof is extended by coupling said one input shaft through a progressively changing rotational speed program from a first maximum rotational speed in one direction of rotation to a second maximum rotational speed in the opposite direction of rotation; the ratios of said planetary gears means being such that synchronous shifting between said low and high speed modes is effected at said first maximum speed of rotation of one input shaft, the improvement wherein: said one input shaft is a quill shaft and said other input shaft is coaxial with said quill shaft and projects completely through said quill shaft for connection at its opposite ends respectively with said power input means and with said high speed planetary gear means; said low speed planetary gear means and said high speed planetary gear means each being centered about said input shafts and including sun gear input means connected to said quill shaft for continuously imparting one input path to both of said planetary gear means; said low speed planetary gear means also including third-element gear means and planet gear means for reacting between said sun gear input means and said third-element gear means and said high speed planetary gear means also including third-element gear means and planet gear means for reacting between said sun gear input means and the third-element gear means of said high speed planetary gear means; said output shaft being aligned with but disposed beyond said input shafts and said high speed planetary gear means being disposed closest to said output shaft; one of the two gear means constituted by said third-element gear means of said high speed planetary gear means and said second planet gear means of said high speed planetary gear means being connected to said output shaft and to said planet gear means of said low speed planetary gear means whereby said output shaft is capable of connection to said sun gear input means through either of said low and high speed planetary gear means and a continuous drive coupling is effected between said low speed and said high speed planetary gear means; said hydrostatic drive unit comprising a driving member mechanically connected to said power input means and a rotatable driven member connected to said quill shaft and including means for infinitely varying the rotational speed of said driven member between said first and said second maximum speeds; brake means for selectively braking said third-element gear means of said low speed planetary gear means to prevent rotation thereof and establish low speed drive; and clutch means for selectively coupling said power input means to the other of said two gear means of the high speed planetary gear means through said other input shaft to establish high speed drive.

Claim 7

A synchronously shiftable, extended range transmission comprising, in combination: an input shaft adapted to be driven in fixed speed ratio with respect to an associated prime mover; a hydrostatic pump fixed to said input shaft and including movable swash plate means for selectively varying the displacement of said pump, said input shaft having an input section leading to said pump and a further section leading from said pump; a quill shaft surrounding said further section of the input shaft and exposing an end portion thereof beyond said quill shaft; a hydrostatic motor fixed to said quill shaft receiving fluid displaced by said pump for rotating said quill shaft to a first maximum rotational speed in a direction opposite to the direction of rotation of said input shaft and then to a second maximum rotational speed in a direction the same as the rotation of said input shaft; a pair of sun gears fixed to said quill shaft in axially spaced relation thereon so that one sun gear is closest to said motor and the other is more remote from said motor; a low speed planetary ring gear concentric with said one sun gear and a high speed planetary ring gear concentric with said other sun gear; low speed planet gear means reacting between said one sun gear and said low speed planetary ring gear, said low speed planetary gear means comprising an inner planet gear in mesh with said one sun gear and an outer planet gear in mesh both with said inner planet gear and said low speed planetary ring gear, and a planet gear carrier rotatably supporting said inner and outer planet gears; high speed planet gear means reacting between said other sun gear and said high speed planetary ring gear, said high speed planet gear means comprising a planet gear meshing with both said other sun gear and said high speed planetary ring gear, and said planet gear of the high speed planet gear means being rotatably carried by said planet gear carrier of the low speed planet gear means whereby the low speed and high speed planet gear means are directly connected through such planet gear carrier; clutch means selectively coupling said high speed planetary ring gear to said end portion of the input shaft exposed beyond said quill shaft; brake means selectively braking said low speed planetary ring gear; and an output shaft coaxial with said input and quill shafts but disposed in spaced relation to said end portion of the input shaft; said planet gear carrier enclosing the high speed planetary gear set formed by said other sun gear, said high speed planetary ring gear and said high speed planet gear means and being directly connected to said output shaft.

Claim 8

A synchronously shiftable, extended range transmission comprising, in combination: an input shaft adapted to be driven in fixed speed ratio with respect to an associated prime mover; a hydrostatic pump fixed to said input shaft and including movable swash plate means for selectively varying the displacement of said pump, said input shaft having an input section leading to said pump and a further section leading from said pump; a quill shaft surrounding said further section of the input shaft and exposing an end portion thereof beyond said quill shaft; a hydrostatic motor fixed to said quill shaft receiving fluid displaced by said pump for rotating said quill shaft to a first maximum rotational speed in a direction opposite to the direction of rotation of said input shaft and then to a second maximum rotational speed in a direction the same as the rotation of said input shaft; a pair of sun gears fixed to said quill shaft in axially spaced relation thereon so that one sun gear is closest to said motor and the other is more remote from said motor; a low speed planetary ring gear concentric with said one sun gear and a high speed planetary ring gear concentric with said other sun gear; low speed planet gear means reacting between said one sun gear and said low speed planetary ring gear, said low speed planetary gear means comprising an inner planet gear in mesh with said one sun gear and an outer planet gear in mesh both with said inner planet gear and said low speed planetary ring gear, and a planet gear carrier rotatably supporting said inner and outer planet gears; high speed planet gear means reacting between said other sun gear and said high speed planetary ring gear, said high speed planet gear means comprising a planet gear meshing with both said other sun gear and said high speed planetary ring gear, and said planet gear of the high speed planet gear means being rotatably carried by said planet gear carrier of the low speed planet gear means whereby the low speed and high speed planet gear means are directly connected through such planet gear carrier; clutch means selectively coupling said high speed planetary ring gear to said end portion of the input shaft exposed beyond said quill shaft; brake means selectively braking said low speed planetary ring gear; and an output shaft coaxial with said input and quill shafts but disposed in spaced relation to said end portion of the input shaft; said planet gear carrier enclosing the high speed planetary gear set formed by said other sun gear, said high speed planetary ring gear and said high speed planet gear means and being directly connected to said output shaft.

Claim 9

A synchronously shiftable, extended range transmission comprising in combination: an input shaft adapted to be driven in fixed speed ratio with respect to an associated prime mover; a hydrostatic pump fixed to said input shaft and including movable swash plate means for selectively varying the displacement of said pump, said input shaft having an input section leading to said pump and a further section leading from said pump; a quill shaft surrounding said further section of the input shaft and exposing an end portion thereof beyond said quill shaft; a hydrostatic motor fixed to said quill shaft receiving fluid displaced by said pump for rotating said quill shaft to a first maximum rotational speed in a direction opposite to the direction of rotation of said input shaft and then to a second maximum rotational speed in a direction the same as the rotation of said input shaft; a low speed planetary gear set surrounding said quill shaft and including a low speed planetary ring gear and low speed planet gear means in mesh with said low speed planetary ring gear; a high speed planetary gear set surrounding said quill shaft to that side of said low speEd planetary gear set opposite said pump and including a high speed planetary ring gear and high speed planet gear means in mesh with said high speed planetary ring gear; an output shaft coaxial with said input and quill shafts but disposed in spaced relation to said end portion of the input shaft which is exposed beyond said quill shaft; a low speed planet gear carrier enclosing said high speed planetary gear set and connected directly to said output shaft, said low speed planet gear means being rotatably carried by said low speed planet gear carrier and one of said high speed planet gear means and said high speed planetary ring gear being carried by said low speed planet gear carrier; clutch means selectively coupling said end portion of the input shaft to that one of said high speed planet gear means and said high speed planetary ring gear which is not carried by said low speed planet gear carrier; brake means selectively braking said low speed planetary ring gear; and sun gear means connected to said quill shaft for rotating said planet gear carrier through at least one of said low speed and high speed planet gear means.

Claim 10

A synchronously shiftable, extended range transmission comprising in combination: an input shaft adapted to be driven in fixed speed ratio with respect to an associated prime mover; a hydrostatic pump fixed to said input shaft and including movable swash plate means for selectively varying the displacement of said pump, said input shaft having an input section leading to said pump and a further section leading from said pump; a quill shaft surrounding said further section of the input shaft and exposing an end portion thereof beyond said quill shaft; a hydrostatic motor fixed to said quill shaft receiving fluid displaced by said pump for rotating said quill shaft to a first maximum rotational speed in a direction opposite to the direction of rotation of said input shaft and then to a second maximum rotational speed in a direction the same as the rotation of said input shaft; a low speed planetary gear set surrounding said quill shaft and including a low speed planetary ring gear and low speed planet gear means in mesh with said low speed planetary ring gear; a high speed planetary gear set surrounding said quill shaft to that side of said low speEd planetary gear set opposite said pump and including a high speed planetary ring gear and high speed planet gear means in mesh with said high speed planetary ring gear; an output shaft coaxial with said input and quill shafts but disposed in spaced relation to said end portion of the input shaft which is exposed beyond said quill shaft; a low speed planet gear carrier enclosing said high speed planetary gear set and connected directly to said output shaft, said low speed planet gear means being rotatably carried by said low speed planet gear carrier and one of said high speed planet gear means and said high speed planetary ring gear being carried by said low speed planet gear carrier; clutch means selectively coupling said end portion of the input shaft to that one of said high speed planet gear means and said high speed planetary ring gear which is not carried by said low speed planet gear carrier; brake means selectively braking said low speed planetary ring gear; and sun gear means connected to said quill shaft for rotating said planet gear carrier through at least one of said low speed and high speed planet gear means.

Claim 11

A synchronously shiftable, extended range transmission as defined in claim 6 wherein said sun gear input means comprises a pair of sun gears fixed to said quill shaft, said low speed planet gear means comprising an inner planet gear meshing with one of said pair of sun gears and an outer planet gear meshing both with said inner planet gear and said low speed planetary ring gear, and said high speed planet gear means comprising a planet gear meshing both with the other of said pair of sun gears and said high speed planetary ring gear, said high speed planet gear means being carried by said planet gear carrier.

Claim 12

A synchronously shiftable, extended range transmission as defined in claim 6 wherein said high speed planet gear means comprises an inner planet gear and an outer planet gear meshing with both said inner planet gear and said high speed planetary ring gear, said sun gear means comprising a single sun gear meshing with said inner planet gear and said low speed planet gear means comprising a planet gear meshing with said low speed planetary ring gear and rotating in unison with said outer planet gear of the high speed planet gear means.

Claim 13

A synchronously shiftable, extended range transmission as defined in claim 6 wherein each of said low speed and said high speed planet gear means comprises an inner planet gear and an outer planet gear in mesh therewith, said sun gear means comprises a pair of sun gears meshing with the inner planet gears of said low speed and high speed planet gear means, and said clutch means selectively couples said end portion of the input shaft to the inner planet gear of said high speed planet gear means.

Claim 14

A synchronously shiftable, extended range transmission as defined in claim 6 wherein each of said low speed and said high speed planet gear means comprises an inner planet gear and an outer planet gear in mesh therewith, said sun gear means comprises a pair of sun gears meshing with the inner planet gears of said low speed and high speed planet gear means, and said clutch means selectively couples said end portion of the input shaft to the inner planet gear of said high speed planet gear means.

Claim 15

A synchronously shiftable, extended range transmission as defined in claim 11 wherein said sun gear input means comprises a pair of sun gears fixed to said quill shaft, said low speed planet gear means comprising an inner planet gear meshing with one of said pair of sun gears and an outer planet gear meshing both with said inner planet gear and said low speed planetary ring gear, and said high speed planet gear means comprising a planet gear meshing both with the other of said pair of sun gears and said high speed planetary ring gear, said high speed planet gear means being carried by said planet gear carrier.

Claim 16

A synchronously shiftable, extended range transmission as defined in claim 11 wherein said high speed planet gear means comprises an inner planet gear and an outer planet gear meshing with both said inner planet gear and said high speed planetary ring gear, said sun gear means comprising a single sun gear meshing with said inner planet gear and said low speed planet gear means comprising a planet gear meshing with said low speed planetary ring gear and rotating in unison with said outer planet gear of the high speed planet gear means.

Claim 17

A synchronously shiftable, extended range transmission as defined in claim 11 wherein said sun gear means comprises a first sun gear meshing with said low speed planet gear means and a second sun gear meshing with said high speed planet gear means, said low speed planet gear means comprising a planet gear meshing both with said first sun gear and said low speed planetary ring gear, said high speed planet gear means comprising a planet gear meshing both with said second sun gear and said high speed planetary ring gear, and said planet gear carrier carrying said high speed planetary ring gear.