Transmission with torque converter and hydrostatic drives

Claim 2

A transmission for a reciprocating piston engine comprising transmission input and output means, a hydrodynamic torque converter having pump means operatively connected to said input means and having turbine means driven by fluid pumped thereto from said pump means, a simple planetary gear unit having a sun gear, a ring gear and planet gears drivingly connecting said sun and ring gears and further having a carrier for said planet gears, means directly connecting said ring gear with said transmission output means, first selectively engageable clutch means for drivingly connecting said turbine means with said planetary carrier of said gear unit, second selectively engageable clutch means operatively connected to said carrier and said sun gear for locking the members of said planetary gear unit together so that said torque converter can drive said output means, a hydrostatic pump unit connected in series with said input means and said torque converter, means directly drivingly connecting said hydrostatic pump unit to said transmission input means, a hydrostatic motor unit hydraulically connected to said hydrostatic pump unit, torque transmitting shaft means directly connecting said hydrostatic motor means to said sun gear of said planetary unit, and displacement control means operatively connected to at least one of said hydrostatic units to provide for the hydrostatic drive of said sun gear when set at a predetermined stroke and said second clutch means is released so that said transmission output means is forwardly driven by said torque converter and said hydrostatic units and to further provide for the overdrive of said output means as the speed of said sun gear is subsequently reduced to zero by reducing the displacement of one of said hydrostatic units to zero.

Claim 3

The transmission of claim 1 wherein a selectively engageable brake means is operatively connected to said carrier so that said displacement control can be increased while said clutches are released and said brake means is engaged to provide for gear multiplied all hydrostatic reverse drives.

Claim 4

In a transmission for an engine having an output that must rotate to prevent engine stall at the start of vehicle drive, transmission input means drivingly connected to the output of the engine, transmission output means, a hydrodynamic torque converter having a rotatable housing, said converter further having pump means drivingly connected to said housing and having turbine and stator means, one way brake means operatively connected to said stator to hold said stator from rotating in one direction to permit said converter to multiply input torque and to release said stator for rotation in an opposite direction so that said converter acts as a fluid coupling when said turbine means accelerates to the speed of said pump, a turbine shaft and an intermediate shaft, first clutch means operatively connected to said shafts and selectively engageable to drivingly connect said turbine shaft to said intermediate shaft, a differential gear unit having a first member drivingly connected to said intermediate shaft, said gear unit having a second member drivingly connected to said transmission output means, said differential unit having a control member, second clutch means operatively connected to said differential unit for locking said differential unit for forward drive through said converter, variable displacement hydrostatic pump anD motor means, said pump means being drivingly connected to said transmission input means, said motor means being drivingly connected to said control member, and displacement control means operatively connected to said hydrostatic units for controlling the displacement of said units and for increasing displacement to a predetermined displacement to drive said control member at a predetermined speed as said second clutch is released to produce a hydrostatic forward drive to said differential and for subsequently decreasing the displacement of said hydrostatic units to reduce the speed of said control member from said predetermined speed for extended output speed forward drive under constant engine speed conditions.

Claim 5

In a transmission for an engine having an output that must rotate to prevent engine stall at the start of vehicle drive, transmission input means drivingly connected to the output of the engine, transmission output means, a hydrodynamic torque converter having a rotatable housing, said converter further having pump means drivingly connected to said housing and having turbine and stator means, one way brake means operatively connected to said stator to hold said stator from rotating in one direction to permit said converter to multiply input torque and to release said stator for rotation in an opposite direction so that said converter acts as a fluid coupling when said turbine means accelerates to the speed of said pump, a turbine shaft and an intermediate shaft, first clutch means operatively connected to said shafts and selectively engageable to drivingly connect said turbine shaft to said intermediate shaft, a differential gear unit having a first member drivingly connected to said intermediate shaft, said gear unit having a second member drivingly connected to said transmission output means, said differential unit having a control member, second clutch means operatively connected to said differential unit for locking said differential unit for forward drive through said converter, variable displacement hydrostatic pump anD motor means, said pump means being drivingly connected to said transmission input means, said motor means being drivingly connected to said control member, and displacement control means operatively connected to said hydrostatic units for controlling the displacement of said units and for increasing displacement to a predetermined displacement to drive said control member at a predetermined speed as said second clutch is released to produce a hydrostatic forward drive to said differential and for subsequently decreasing the displacement of said hydrostatic units to reduce the speed of said control member from said predetermined speed for extended output speed forward drive under constant engine speed conditions.

Claim 6

The transmission defined in claim 3 wherein said differential gear unit is a planetary gearset, said first and second members and said control member comprising a planetary gear carrier, a ring gear and a sun gear respectively of said planetary gearset which cooperate to provide an overdrive ratio when said sun gear is held stationary and when driven in a rearward direction by said hydrostatic motor and the carrier is driven by the vehicle engine, and selectively engageable brake means operatively connected to said carrier for providing for gear multiplied hydrostatic reverse drives of said output means when said clutches are released and said hydrostatic motor drives said sun gear.