Power transmission mechanism

Claim 2

A power transmission mechanism comprising a driving shaft, means for operably drive connecting one end of said driving shaft to a prime mover, a hydrostatic drive assembly surrounding said driving shaft which passes therethrough, a power takeoff shaft, means drivably connecting the other end of said driving shaft directly to said power takeoff shaft, an output shaft, means comprising a single epicyclic gear drivably connecting said other end of said driving shaft to said hydrostatic drive assembly and to said output shaft, and means for drivably connecting said hydrostatic drive assembly to said output shaft.

Claim 3

A power transmission mechanism according to claim 1, comprising means for varying drive torque transmitted to the output shaft by said hydrostatic drive assembly whereby power for varying to said output shaft is controllably divisible between a mechanical power path and a hydrostatic power path.

Claim 4

A power transmission mechanism according to claim 2, provided with means for causing a state of lock in the hydrostatic path, and thus a purely mechanical output drive at an intermediate gear ratio between the high and low limits of the range of gear ratios obtainable from the mechanism.

Claim 5

In the power transmission mechanism defined in claim 1, said output shaft comprising a rotatable sleeve surrounding said power takeoff shaft, and said epicyclic gear comprising a sun gear rotatable with said driving and power takeoff shafts, a ring gear drivingly connected to said hydrostatic drive assembly, and a planet gear carrier rotatable with said sleeve.

Claim 6

A power transmission mechanism comprising a driving shaft, means operably drive connecting one end of said driving shaft to a prime mover, a hydrostatic drive assembly surrounding said driving shaft which passes therethrough, a power takeoff shaft, means drivably connecting the other end of said driving shaft directly to said power takeoff shaft, means comprising a single epicyclic gear drivably connecting said other end of said driving shaft to said hydrostatic drive assembly and comprising means drivably connecting said other end of the driving shaft to one member of said single epicyclic gear, an output shaft drivably connected to a second member of said single epicyclic gear, a first unit of said hydrostatic drive assembly drivably connected to the third member of said single epicyclic gear, a second unit of said hydrostatic drive assembly selectively connectable to said driving shaft by first clutch means and to said output shaft by second clutch means and speed reduction gearing, and a closed hydraulic circuit interconnecting said first and second units of the hydrostatic drive assembly.

Claim 7

A power transmission mechanism comprising a driving shaft, means operably drive connecting one end of said driving shaft to a prime mover, a hydrostatic drive assembly surrounding said driving shaft which passes therethrough, a power takeoff shaft, means drivably connecting the other end of said driving shaft directly to said power takeoff shaft, means comprising a single epicyclic gear drivably connecting said other end of said driving shaft to said hydrostatic drive assembly and comprising means drivably connecting said other end of the driving shaft to one member of said single epicyclic gear, an output shaft drivably connected to a second member of said single epicyclic gear, a first unit of said hydrostatic drive assembly drivably connected to the third member of said single epicyclic gear, a second unit of said hydrostatic drive assembly selectively connectable to said driving shaft by first clutch means and to said output shaft by second clutch means and speed reduction gearing, and a closed hydraulic circuit interconnecting said first and second units of the hydrostatic drive assembly.

Claim 8

A powEr transmitting mechanism as defined in claim 5, wherein said first epicyclic gear member is a sun gear drive connected to said driving shaft, said second epicyclic gear member comprises an associated planet carrier having a sleeve that extends to form said output shaft, and said third epicyclic gear member comprises a toothed annulus having a sleeve surrounding said driving shaft and directly drive connected to said first hydrostatic drive assembly unit.

Claim 9

A power transmission mechanism according to claim 5, said second unit of said hydrostatic drive assembly being connectable to said driving shaft by speed-increasing gearing.

Claim 10

A power transmission mechanism according to claim 5, wherein each said unit of said hydrostatic drive assembly is of variable capacity.

Claim 11

A power transmission mechanism according to claim 5, wherein each said unit of said hydrostatic drive assembly is of an axial-piston swashplate type.

Claim 12

A power transmission mechanism according to claim 5, wherein said hydrostatic drive assembly consists essentially of two said units.

Claim 13

A power transmission mechanism according to claim 1, wherein said driving shaft is connectable at said one end to an input shaft from the prime mover by reverse gearing.

Claim 14

A power transmission mechanism comprising a driving shaft, means operably drive connecting one end of said driving shaft to a prime mover, reverse gearing for connecting an input shaft from said prime mover to said driving shaft, said reverse gearing comprising a first pair of coaxial gears which mesh respectively with a gear on said input shaft and a gear on said driving shaft, a second pair of coaxial gears one of which meshes with one of said first pair of gears, an idler gear which meshes with the other of said second pair of gears, and clutch means for selectively connecting together either, but not both, of said pairs of gears, a hydrostatic drive assembly surrounding said driving shaft which passes therethrough, a power takeoff shaft, means drivably connecting the other end of said driving shaft directly to said power takeoff shaft, and means comprising a single epicyclic gear drivably connecting said other end of said driving shaft to said hydrostatic drive assembly.

Claim 15

A power transmission mechanism comprising a driving shaft, means operably drive connecting one end of said driving shaft to a prime mover, reverse gearing for connecting an input shaft from said prime mover to said driving shaft, said reverse gearing comprising a first pair of coaxial gears which mesh respectively with a gear on said input shaft and a gear on said driving shaft, a second pair of coaxial gears one of which meshes with one of said first pair of gears, an idler gear which meshes with the other of said second pair of gears, and clutch means for selectively connecting together either, but not both, of said pairs of gears, a hydrostatic drive assembly surrounding said driving shaft which passes therethrough, a power takeoff shaft, means drivably connecting the other end of said driving shaft directly to said power takeoff shaft, and means comprising a single epicyclic gear drivably connecting said other end of said driving shaft to said hydrostatic drive assembly.