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US 4,304,151 AGranted
Stepless composite hydrostatic-mechanical transmission
AssigneeZahnradfabrik Friedrichshafen AG
InventorsMichael Meyerle, Anton Ott, Friedrich Ehrlinger
Life of this patent
Estimating the term…
Abstract
A composite transmission with power branching between a hydrostatic transmission and a mechanical summing transmission in which the hydrostatic transmission has a variable displacement unit. The input shaft is connected to the variable displacement unit and to a ring gear on the four-shaft summing transmission of which the ring gear and sun gear are selectively connectible by respective clutches to the constant displacement hydraulic unit. The planet carrier of the summing transmission is connected to the output shaft. The output shaft can also be directly coupled to the input shaft by a clutch and a further planetary can be provided between the fourth shaft of the summing transmission and the output shaft.
Claims14
A steplessly adjustable hydrostatic-mechanical composite transmission comprising:
- an input shaft connectible to a prime mover and an output shaft connectible to a load;
- a hydrostatic transmission comprising two hydraulic machine units connected in a closed hydraulic circuit and having respective shafts, a first of said units being of variable displacement type shiftable from an extreme negative setting to an extreme positive setting through a zero displacement setting;
- a four-shaft planetary summing transmission having a first shaft, second shaft, a third shaft, a fourth shaft and planetary gearing interconnecting said first, second, third and fourth shafts for correlated operation, said first, second, third and fourth shafts being coaxial;
- means connecting said input shaft to a first shaft of said summing transmission;
- means connecting said input shaft to the shaft of one of said units;
- respective clutches coaxial with said first, second, third and fourth shafts, connecting the shaft of the other of said units to second and third shafts of said summing transmission, respectively, and being selectively individually and collectively actuatable, said clutches on joint actuation causing the planetary gearing of said summing transmission to rotate as a unit;
- and
- means including a selectively actuatable reversing transmission for connecting said fourth shaft of said summing transmission with said output shaft.
5 more elements
A steplessly adjustable hydrostatic-mechanical composite transmission comprising:
- an input shaft connectible to a prime mover and an output shaft connectible to a load;
- a hydrostatic transmission comprising two hydraulic machine units connected to a closed hydraulic circuit and having respective shafts, a first of said units being of variable displacement type shiftable from an extreme negative setting to an extreme positive setting through a zero displacement setting;
- a four-shaft planetary summing transmission having a first shaft, a second shaft, a third shaft, a fourth shaft and planetary gearing interconnecting said first, second, third and fourth shafts for correlated operation;
- means connecting said input shaft to a first shaft of said summing transmission;
- means connecting said input shaft to the shaft of one of said units;
- respective clutches connecting the shaft of the other said units to second and third shafts of said summing transmission, respectively, and being selectively individually and collectively actuatable;
- means for connecting said fourth shaft of said summing transmission with said output shaft, the means connecting the fourth shaft of said summing transmission to the output shaft being a reversing transmission;
- and
- a further clutch operatively connecting the input shaft to the output shaft and forming a power bypass for said summing transmission and said hydrostatic transmission.
6 more elements
A steplessly adjustable hydrostatic-mechanical composite transmission comprising:
- an input shaft connectible to a prime mover and output shaft connectible to a load;
- a hydrostatic transmission comprising two hydraulic machine units connected to a closed hydraulic circuit and having respective shafts, a first of said units being of variable displacement type shiftable from an extreme negative setting to an extreme positive setting through a zero displacement setting;
- a four-shaft planetary summing transmission having a first shaft, a second shaft, a third shaft, a fourth shaft and planetary gearing interconnecting said first, second, third and fourth shafts for correlated operation;
- means connecting said input shaft to a first shaft of said summing transmission;
- means connecting said input shaft to the shaft of one of said units;
- respective clutches connecting the shaft of the other of said units to second and hird shafts of said summing transmission, respectively and being selectively individually and collectively actuatable;
- means for connecting said fourth shaft of said summing transmission with said output shaft, the means connecting the fourth shaft of said summing transmission to the output shaft being a reversing transmission;
- and
- a shunt valve connected across said hydraulic circuit and effective in the neutral setting of the composite transmission and upon direct coupling of the input and output shafts together.
6 more elements
A steplessly adjustable hydrostatic-mechanical composite transmission comprising:
- an input shaft connectible to a prime mover and an output shaft connectible to a load;
- a hydrostatic transmission comprising two hydraulic machine units connected to a closed hydraulic circuit and having respective shafts, a first of said units being of variable displacement type shiftable from an extreme negative setting to an extreme positive setting through a zero displacement setting;
- a four-shaft planetary summing transmission having a first shaft, a second shaft, a third shaft, a fourth shaft and planetary gearing interconnecting said first, second, third and fourth shafts for correlated operation;
- means connecting said input shaft to a first shaft of said summing transmission;
- means connecting said input shaft to the shaft of one of said units;
- respective clutches connecting the shaft of the other of said units to second and third shafts of said summing transmission, respectively and being selectively individually and collectively actuatable;
- means for connecting said fourth shaft of said summing transmission with said output shaft, said first shaft of said summing transmission being connected to a first ring gear, said second and third shafts of said summing transmission being respectively connected to a second ring gear and a sun gear and said fourth shaft of said summing transmission being connected to a planetary carrier, said planetary carrier being provided with planet gears meshing with said ring gear and with said sun gear, said first unit being said one of said units, said other of said units being a constant-displacement hydraulic machine;
- and
- a clutch between said input shaft and said output shaft for the direct connection thereof together.
6 more elements
Dependencies are inferred from the claim text.