Hydromechanical transmission

Claim 2

In a transmission the combination of an input shaft; an output shaft; variable-ratio hydrostatic drive means including a pump connected to be driven by said input shaft and further including a motor hydraulically connected to said pump; a pair of planetary gearsets each comprising a sun gear member, a ring gear member and a carrier member carrying a pinion meshing with the sun gear member and ring gear member; one member of each said gearset connected to be driven by said motor; another member of one of said gearsets and another member of the other of said gearsets connected to each other and also connected to drive said output shaft; first drive-establishing means for selectively preventing rotation of the third member of said one gearset in either a forward or reverse direction; second drive-establishing means including one-way brake means for selectively preventing said third member of said one gearset from rotating in said reverse direction while permitting free forward rotation thereof; third drive-establishing meAns including one-way clutch means for selectively connecting said input shaft to drive the third member of said other gearset in said forward direction; and fourth drive-establishing means for selectively connecting said input shaft to drive said third member of said one gearset whereby there is provided a low speed range forward drive on operation of only said second drive-establishing means; an intermediate-speed range forward drive on operation of only said third driveestablishing means while said second drive-establishing means remains operational, a high-speed range forward drive on operation of only said fourth drive-establishing means while both said second and third drive-establishing means remain operational and a low speed range forward and reverse drive on operation of only said first drive-establishing means.

Claim 3

The transmission set forth in claim 1 and said input shaft and said output shaft having parallel axes; said first, second and fourth drive-establishing means including a common gear train; said gear train comprising a first gear concentric with said output shaft and connected to said one gear member of said one gearset and a second gear concentric with said input shaft and in mesh with said first gear.

Claim 4

The transmission set forth in claim 2 and said third drive-establishing means including a gear train comprising a first gear concentric with said output shaft and connected to said third member of said other gearset and a second gear concentric with said input shaft and in mesh with the first gear.

Claim 5

The transmission set forth in claim 3 and said first drive-establishing means including brake means concentric with said input shaft; and said second drive-establishing means including brake means in series with said one-way brake means; both said brake means and said one-way brake means of said second drive-establishing means concentric with said input shaft; said third drive-establishing means including clutch means in series with said one-way clutch means; both said clutch means and said one-way clutch means concentric with said input shaft; said fourth drive-establishing means including clutch means concentric with said input shaft.

Claim 6

In a transmission the combination of an input shaft; an output shaft; variable-ratio hydrostatic drive means including a pump connected to be driven by said input shaft and further including a motor hydraulically connected to said pump; a pair of planetary gearsets each comprising a sun gear, a ring gear and a carrier carrying a pinion meshing with the sun gear and ring gear; both said sun gears connected to be driven by said motor; the carrier of one of said gearsets and the ring gear of the other of said gearsets connected to each other and also connected to said output shaft; means including a one-way brake for braking said ring gear of said one gearset against rotation in only one direction; means including a one-way clutch for connecting said input shaft to drive the carrier of said other gearset; and means for connecting said input shaft to drive said ring gear of said one gearset.

Claim 7

In a transmission the combination of an input shaft; an output shaft; variable-ratio hydrostatic drive means including a pump connected to be driven by said input shaft and further including a motor hydraulically connected to said pump; a pair of planetary gearsets each comprising a sun gear, a ring gear and a carrier carrying a pinion meshing with the sun gear and ring gear; both said sun gears connected to be driven by said motor; the carrier of one of said gearsets and the ring gear of the other of said gearsets connected to each other and also connected to said output shaft; means including a one-way brake for braking said ring gear of said one gearset against rotation in only one direction; means including a one-way clutch for connecting said input shaft to drive the carrier of said other gearset; and means for connecting said input shaft to drive said ring gear of said one gearset.

Claim 8

In a transmission the combination of an input shaft; an output shaft arranged parallel to said input shaft; variable-ratio hydrostatic drive means including a pump concentric with said input shaft and connected to be driven by said input shaft and further including a motor concentric with said output shaft and hydraulically connected to said pump; a pair of planetary gearsets each comprising a sun gear, a ring gear and a carrier carrying a pinion meshing with the sun gear and ring gear; both said sun gears connected to be driven by said motor; the carrier of one of the gearsets and the ring gear of the other of said gearsets connected to each other and also connected to said output shaft; a first gear train comprising a first gear concentric with said output shaft and connected to the ring gear of said one gearset and a second gear concentric with said input shaft and in mesh with said first gear; a first brake operablE to brake said second gear of said first gear train to prevent rotation of the ring gear of said one gearset in either a forward or reverse direction; a second brake and a one-way brake in series therewith operable to brake said second gear of said first gear train against rotation in only one direction to prevent said ring gear of said one gearset from rotating in said reverse direction while permitting free forward rotation thereof; a first clutch operable to connect said input shaft to said second gear of said first gear train so that said ring gear of said one gearset is driven in said forward direction by said input shaft; a second gear train comprising a first gear concentric with said output shaft and connected to the carrier of said other gearset and a second gear concentric with said input shaft and in mesh with said first gear; and a second clutch and a one-way clutch in series therewith operable to connect said input shaft to the second gear of said second gear train so that the carrier of said other gearset is driven in said forward direction by said input shaft and is permitted to rotate freely in said forward direction when said first clutch is engaged.

Claim 9

In a transmission the combination of an input shaft; an output shaft arranged parallel to said input shaft; variable-ratio hydrostatic drive means including a pump concentric with said input shaft and connected to be driven by said input shaft and further including a motor concentric with said output shaft and hydraulically connected to said pump; a pair of planetary gearsets each comprising a sun gear, a ring gear and a carrier carrying a pinion meshing with the sun gear and ring gear; both said sun gears connected to be driven by said motor; the carrier of one of the gearsets and the ring gear of the other of said gearsets connected to each other and also connected to said output shaft; a first gear train comprising a first gear concentric with said output shaft and connected to the ring gear of said one gearset and a second gear concentric with said input shaft and in mesh with said first gear; a first brake operablE to brake said second gear of said first gear train to prevent rotation of the ring gear of said one gearset in either a forward or reverse direction; a second brake and a one-way brake in series therewith operable to brake said second gear of said first gear train against rotation in only one direction to prevent said ring gear of said one gearset from rotating in said reverse direction while permitting free forward rotation thereof; a first clutch operable to connect said input shaft to said second gear of said first gear train so that said ring gear of said one gearset is driven in said forward direction by said input shaft; a second gear train comprising a first gear concentric with said output shaft and connected to the carrier of said other gearset and a second gear concentric with said input shaft and in mesh with said first gear; and a second clutch and a one-way clutch in series therewith operable to connect said input shaft to the second gear of said second gear train so that the carrier of said other gearset is driven in said forward direction by said input shaft and is permitted to rotate freely in said forward direction when said first clutch is engaged.