Hybrid vehicle drive system having clutch between engine and synthesizing/distributing mechanism which is operatively connected to motor/generator

A hybrid drive system for a motor vehicle, comprising:

• an engine operated by combustion of a fuel;
• an electric energy storage device for storing an electric energy;
• a motor/generator connected to said electric energy storage device;
• a first clutch;
• a synthesizing/distributing mechanism including a first rotary element connected to said engine through said first clutch, a second rotary element connected to said motor/generator, a third rotary element, and an output member connected to said third rotary element;
• and
• a second clutch for connecting two elements of said first, second and third rotary elements of said synthesizing/distributing mechanism, for rotation of said two elements as a unit,
• and wherein said synthesizing/distributing mechanism comprises a planetary gear device which includes a ring gear as said first rotary element, a sun gear as said second rotary element, and a carrier as said third rotary element, said motor/generator having a torque capacity which is about .rho. times a maximum torque of said engine, where .rho. is a ratio of the number of teeth of said sun gear to the number of teeth of said ring gear.

A hybrid drive system for a motor vehicle, comprising:

• an engine operated by combustion of a fuel;
• an electric energy storage device for storing an electric energy;
• a motor/generator connected to said electric energy storage device;
• a first clutch;
• a synthesizing/distributing mechanism including a first rotary element connected to said engine through said first clutch, a second rotary element connected to said motor/generator, a third rotary element, and an output member connected to said third rotary element, said synthesizing/distributing mechanism comprising a planetary gear device which includes a ring gear as said first rotary element, a sun gear as said second rotary element, and a carrier as said third rotary element;
• a second clutch for connecting two elements of said first, second and third rotary elements of said synthesizing/distributing mechanism, for rotation of said two elements as a unit;
• and
• a brake for inhibiting rotation of said ring gear.

A hybrid drive system for a motor vehicle, comprising:

• an engine operated by combustion of a fuel;
• an electric energy storage device for storing an electric energy;
• a motor/generator connected to said electric energy storage device;
• a first clutch;
• a synthesizing/distributing mechanism including a first rotary element connected to said engine through said first clutch, a second rotary element connected to said motor/generator, a third rotary element, and an output member connected to said third rotary element, said synthesizing/distributing mechanism comprising a planetary gear device which includes a ring gear as said first rotary element, a sun gear as said second rotary element, and a carrier as said third rotary element;
• a second clutch for connecting two elements of said first, second and third rotary elements of said synthesizing/distributing mechanism, for rotation of said two elements as a unit;
• and
• a one-way clutch for permitting rotation of said ring gear in the same direction as said engine and inhibiting rotation of said ring gear in a direction opposite to a direction of rotation of said engine.

A hybrid drive system for a motor vehicle, comprising:

• an engine operated by combustion of a fuel;
• an electric energy storage device for storing an electric energy;
• a motor/generator connected to said electric energy storage device;
• a first clutch;
• a synthesizing/distributing mechanism including a first rotary element connected to said engine through said first clutch, a second rotary element connected to said motor/generator, a third rotary element, and an output member connected to said third rotary element;
• and
• a second clutch for connecting two elements of said first, second and third rotary elements of said synthesizing/distributing mechanism, for rotation of said two elements as a unit,
• and wherein said engine, said synthesizing/distributing mechanism, and said motor/generator are arranged in the order of description, coaxially with a first axis, said hybrid drive system further comprising a differential gear device for distributing power received from said output member to a right wheel and a left wheel of the motor vehicle, said differential gear device including a pair of output shafts which are parallel to said first axis, an input member disposed at substantially the same position as said output member in an axial direction of said first axis, and a differential gear mechanism disposed at substantially the same position as said synthesizing/distributing mechanism in said axial direction.