HYBRID POWERTRAIN WITH TORQUE-MULTIPLYING ENGINE STARTING MECHANISM AND METHOD OF CONTROLLING A HYBRID POWERTRAIN
First Claim
1. A hybrid powertrain comprising:
- an engine with an engine output member;
a transmission with a transmission input member;
a motor/generator configured to apply torque to the transmission input member;
a first clutch selectively engagable to connect the engine output member for common rotation with the transmission input member; and
an engine starting mechanism including;
a first and a second gear train; and
a second clutch having a first portion connected with the transmission input member via the first gear train and a second portion connected with the engine output member via the second gear train, and selectively engagable to transfer torque from the transmission input member to the engine output member with torque multiplication.
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Accused Products
Abstract
A hybrid powertrain is provided that provides engine starting from an electric-only mode with a reduced torque load on the motor/generator. The powertrain includes an engine and a motor/generator, which may be a single motor/generator in a strong or full hybrid, but is not limited to such. The motor provides propulsion torque in an electric-only operating mode, and is configured to apply torque to a transmission input member. A first clutch is selectively engagable to connect the engine output member for common rotation with the transmission input member. An engine starting mechanism is provided that multiplies motor torque used to start the engine so that less is diverted from propelling the vehicle, enabling a smaller motor/generator to be used. A method of controlling such a powertrain is also provided.
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Citations
12 Claims
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1. A hybrid powertrain comprising:
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an engine with an engine output member; a transmission with a transmission input member; a motor/generator configured to apply torque to the transmission input member; a first clutch selectively engagable to connect the engine output member for common rotation with the transmission input member; and an engine starting mechanism including; a first and a second gear train; and a second clutch having a first portion connected with the transmission input member via the first gear train and a second portion connected with the engine output member via the second gear train, and selectively engagable to transfer torque from the transmission input member to the engine output member with torque multiplication. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of controlling a hybrid powertrain having an engine with an engine output member, a transmission with a transmission input member, a motor/generator configured to apply torque to the transmission input member, and a first clutch selectively engagable to connect the engine output member for common rotation with the transmission input member;
- the method comprising;
engaging a second clutch to transfer torque from the motor/generator to the engine to start the engine during an electric-only operating mode;
wherein the second clutch connects the motor/generator to the engine via gear trains configured to multiply motor torque. - View Dependent Claims (9, 10, 11)
- the method comprising;
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12. A hybrid powertrain comprising:
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an engine with an engine output member; a transmission with a transmission input member; a motor/generator configured to apply torque to the transmission input member; a hydraulically-actuated friction plate clutch selectively engagable to connect the engine output member for common rotation with the transmission input member; an active material clutch having a first portion connected with the transmission input member via a first gear train and a second portion connected with the engine output member via a second gear train, and selectively engagable to transfer torque from the transmission input member to the engine output member with torque multiplication;
wherein the first gear train includes a first gear connected for rotation the transmission input member and a second gear connected for rotation with the first portion of the active material clutch;
wherein the second gear train includes a spur gear connected for rotation with the second portion of the second clutch and meshing with a ring gear connected for rotation with the engine output member;
wherein the gear ratio of the ring gear to the spur gear is greater than the gear ratio of the second gear to the first gear.
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Specification