Gas turbine engine and hydromechanical transmission vehicle drive

Claim 2

A power drive system for a vehicle comprising, a gas turbine engine having free turbine output means operable through a speed range for providing variable output torques and speed and having a maximum output torque at zero output speed; a variable ratio hydrostatic transmission including variable displacement pump means and motor means each having a maximum displacement and pressure limitation for limiting the torque transmission of said hydrostatic transmission at a value less than said maximum output torque of said free turbine output means; drive means disposed between said free turbine output means and said hydrostatic transmission for providing a drive relationship therebetween; transmission output means for delivering power from said drive system; planetary gear means including a sun gear drivingly connected with said hydrostatic transmission, a ring gear drivingly connected with said transmission output means, a carrier member, and pinion gear means rotatably mounted on said carrier member and meshing with said sun and ring gear; first selectively engageable clutch means for connecting said sun gear and said carrier member together; second selectively engageaBle clutch means for connecting said drive means and said carrier member together and cooperating with said first clutch means for providing a low speed drive range which transmits engine torque directly from said drive means to said transmission output means through a mechanical drive path only; and servo means for varying the displacement of said pump means for controlling said pump and motor displacements at equal values when both said clutch means are engaged and said pump means and motor means are rotated in unison when the mechanical drive path having a speed-torque characteristic substantially equal to the engine speed torque characteristic is provided and for varying the displacement of said pump relative to the displacement of said motor when said first clutch means is disengaged and said second clutch means is engaged to provide a hydromechanical high speed drive range defining a substantially continuous output speed-torque characteristic.

Claim 3

A variable speed power drive system for a vehicle comprising a free turbine gas turbine engine having free turbine output means for providing a power output therefrom through a speed range including zero output speed and a torque range having a maximum torque at zero output speed; a hydromechanical transmission including a variable ratio hydrostatic transmission having a variable displacement pump, a motor and means for controlling the displacement of said variable displacement pump, first continuous drive means connected between said free turbine output means and said pump for providing a continuous drive therebetween, planetary gear means including a sun gear, a ring gear, a carrier member and pinions rotatably mounted on said carrier member meshing with said sun and ring gears, second continuous drive means connected between said motor and said sun gear, first selectively engageable clutch means disposed between said first continuous drive means and said carrier member for providing a selective drive connection therebetween to establish a forward low range mechanical drive in said system, second selectively engageable clutch means between said second continuous drive means and said carrier member for providing a selective drive connection therebetween when the low forward drive range is desired and said pump displacement is equal to the motor displacement to provide a mechanical only drive path which has a speed-torque characteristic substantially equal to the engine speed-torque characteristic, selectively engageable brake means for preventing rotation of said carrier member when a reverse drive range is desired and both said clutch means are disengaged, said second clutch means being disengaged and said first clutch means remaining engaged to provide a second and high forward drive range having a mechanical component from said free turbine output means and a hydrostatic component from said hydrostatic transmission to provide a hydromechanical high speed drive range having a speed-torque characteristic defining a substantially constant power output; and output means continuously connected with said ring gear to deliver the drives from said hydromechanical transmission.

Claim 4

A variable speed power drive system for a vehicle comprising a free turbine gas turbine engine having free turbine output means for providing a power output therefrom through a speed range including zero output speed and a torque range having a maximum torque at zero output speed; a hydromechanical transmission including a variable ratio hydrostatic transmission having a variable displacement pump, a motor and means for controlling the displacement of said variable displacement pump, first continuous drive means connected between said free turbine output means and said pump for providing a continuous drive therebetween, planetary gear means including a sun gear, a ring gear, a carrier member and pinions rotatably mounted on said carrier member meshing with said sun and ring gears, second continuous drive means connected between said motor and said sun gear, first selectively engageable clutch means disposed between said first continuous drive means and said carrier member for providing a selective drive connection therebetween to establish a forward low range mechanical drive in said system, second selectively engageable clutch means between said second continuous drive means and said carrier member for providing a selective drive connection therebetween when the low forward drive range is desired and said pump displacement is equal to the motor displacement to provide a mechanical only drive path which has a speed-torque characteristic substantially equal to the engine speed-torque characteristic, selectively engageable brake means for preventing rotation of said carrier member when a reverse drive range is desired and both said clutch means are disengaged, said second clutch means being disengaged and said first clutch means remaining engaged to provide a second and high forward drive range having a mechanical component from said free turbine output means and a hydrostatic component from said hydrostatic transmission to provide a hydromechanical high speed drive range having a speed-torque characteristic defining a substantially constant power output; and output means continuously connected with said ring gear to deliver the drives from said hydromechanical transmission.

Claim 5

A variable speed power drive system for a vehicle comprising a free turbine gas turbine engine having free turbine output means for providing a power output therefrom through a speed range including zero output speed and a torque range having a maximum torque at zero output speed; a hydromechanical transmission including a variable ratio hydrostatic transmission having a variable displacement pump, a variable displacement motor and means for controlling the displacement of each of said variable displacement pump and motor, forward-reverse drive means connected between said free turbine output means and said pump for selectively providing forward and reverse drives therebetween, planetary gear means including a sun gear, a ring gear, a carrier member and pinions rotatably mounted on said carrier member meshing with said sun and ring gears, drive means conneCted between said motor and said sun gear, first selectively engageable clutch means disposed between said forward-reverse drive means and said carrier member for providing a selective mechanical only drive path connection therebetween to establish a forward and a reverse low range in said system having a speed-torque characteristic substantially equal to the engine speed-torque characteristic, second selectively engageable clutch means between said drive means and said carrier member cooperating with said first clutch means for providing the selective mechanical only drive connection therebetween when the low forward drive range is desired and said pump displacement is equal to the motor displacement, said second clutch means being disengaged and said first clutch means remaining engaged to provide a second and high forward and reverse drive range having a mechanical component from said free turbine output means and a hydrostatic component from said hydrostatic transmission to provide a hydromechanical high speed drive range having a speed-torque characteristic defining a substantially constant power output; and output means continuously connected with said ring gear to deliver the drives from said hydromechanical transmission.

Claim 6

A variable speed power drive system for a vehicle comprising a free turbine gas turbine engine having free turbine output means for providing a power output therefrom through a speed range including zero output speed and a torque range having a maximum torque at zero output speed; a hydromechanical transmission including a variable ratio hydrostatic transmission having a variable displacement pump, a variable displacement motor and means for controlling the displacement of each of said variable displacement pump and motor, forward-reverse drive means connected between said free turbine output means and said pump for selectively providing forward and reverse drives therebetween, planetary gear means including a sun gear, a ring gear, a carrier member and pinions rotatably mounted on said carrier member meshing with said sun and ring gears, drive means conneCted between said motor and said sun gear, first selectively engageable clutch means disposed between said forward-reverse drive means and said carrier member for providing a selective mechanical only drive path connection therebetween to establish a forward and a reverse low range in said system having a speed-torque characteristic substantially equal to the engine speed-torque characteristic, second selectively engageable clutch means between said drive means and said carrier member cooperating with said first clutch means for providing the selective mechanical only drive connection therebetween when the low forward drive range is desired and said pump displacement is equal to the motor displacement, said second clutch means being disengaged and said first clutch means remaining engaged to provide a second and high forward and reverse drive range having a mechanical component from said free turbine output means and a hydrostatic component from said hydrostatic transmission to provide a hydromechanical high speed drive range having a speed-torque characteristic defining a substantially constant power output; and output means continuously connected with said ring gear to deliver the drives from said hydromechanical transmission.

Claim 7

A variable speed power drive system for a vehicle comprising a free turbine gas turbine engine having free turbine output means for providing a power output therefrom through a speed range including zero output speed and a torque range having a maximum torque at zero output speed; a hydromechanical transmission including a variable ratio hydrostatic transmission having a variable displacement pump, a variable displacement motor and means for controlling the displacement of each of said variable displacement pump and motor, forward-reverse drive means connected between said free turbine output means and said pump for selectively providing forward and reverse drives therebetween, planetary gear means including a sun gear, a ring gear, a carrier member and pinions rotatably mounted on said carrier member meshing with said sun and ring gears, drive means connected between said motor and said sun gear, first selectively engageable clutch means disposed between said forward-reverse drive means and said carrier member for providing a selective drive connection therebetween to establish a forward and a reverse low range mechanical drive in said system, second selectively engageable clutch means between said drive means and said carrier member cooperating with said first clutch means for providing a selective mechanical only drive connection therebetween when the low forward drive range is desired and said pump displacement is equal to the motor displacement, said second clutch means being disengaged and said first clutch means remaining engaged to provide a second and high forward and reverse drive range having a mechanical component from said free turbine output means and a hydrostatic component from said hydrostatic transmission; and output means continuously connected with said ring gear to deliver the drives from said hydromechanical transmission.

Claim 8

A variable speed power drive system for a vehicle comprising a free turbine gas turbine engine having free turbine output means for providing a power output therefrom through a speed range including zero output speed and a torque range having a maximum torque at zero output speed; a hydromechanical transmission including a variable ratio hydrostatic transmission having a variable displacement pump, a variable displacement motor and means for controlling the displacement of each of said variable displacement pump and motor, forward-reverse drive means connected between said free turbine output means and said pump for selectively providing forward and reverse drives therebetween, planetary gear means including a sun gear, a ring gear, a carrier member and pinions rotatably mounted on said carrier member meshing with said sun and ring gears, drive means connected between said motor and said sun gear, first selectively engageable clutch means disposed between said forward-reverse drive means and said carrier member for providing a selective drive connection therebetween to establish a forward and a reverse low range mechanical drive in said system, second selectively engageable clutch means between said drive means and said carrier member cooperating with said first clutch means for providing a selective mechanical only drive connection therebetween when the low forward drive range is desired and said pump displacement is equal to the motor displacement, said second clutch means being disengaged and said first clutch means remaining engaged to provide a second and high forward and reverse drive range having a mechanical component from said free turbine output means and a hydrostatic component from said hydrostatic transmission; and output means continuously connected with said ring gear to deliver the drives from said hydromechanical transmission.