400h CVT
400h CVT
03-20-07, 08:36 PM
#2
Lexus Test Driver
Power Split CVT Transmission
ere's an excerpt on the hybrid CVT transmission, courtesy of HowStuffWorks:
The power split transmission (PST) is a transmission that uses two different types of power sources for separate inputs to produce one output, usually in conjunction with an epicyclic gear system (which is also known as a planetary gear system) that includes three fundamental gearing components. The PST is the essential method for transmitting power in most hybrid vehicles, usually enabling an Internal Combustion Engine (ICE) to be used in conjunction with an electric motor and/or motor-generator for vehicle propulsion.
The PST and power sources are controlled to provide a balance between the power sources that increases vehicle fuel economy while providing advantageous performance when needed. The PST may also be used to provide electrically generated power to charge large storage batteries for subsequent electric motor propulsion as needed, or to convert vehicle kinetic energy to electricity through 'regenerative braking' during deceleration. Various configurations of power generation, usage and balance can be implemented with a PST, enabling great flexibility in propelling hybrid vehicles.
To date, The Toyota Prius and Honda Insight are well known hybrid vehicles that use PST's. Applications of PST's are growing rapidly in number and variety.
The PST should not be confused with Continuously Variable Transmissions (CVT's) that use only a single source of power. PST's are capable of continuously modulating output/input speed ratios like CVT's, but they are fundamentally different devices, neither being a categorical subset of the other.
The power split transmission (PST) is a transmission that uses two different types of power sources for separate inputs to produce one output, usually in conjunction with an epicyclic gear system (which is also known as a planetary gear system) that includes three fundamental gearing components. The PST is the essential method for transmitting power in most hybrid vehicles, usually enabling an Internal Combustion Engine (ICE) to be used in conjunction with an electric motor and/or motor-generator for vehicle propulsion.
The PST and power sources are controlled to provide a balance between the power sources that increases vehicle fuel economy while providing advantageous performance when needed. The PST may also be used to provide electrically generated power to charge large storage batteries for subsequent electric motor propulsion as needed, or to convert vehicle kinetic energy to electricity through 'regenerative braking' during deceleration. Various configurations of power generation, usage and balance can be implemented with a PST, enabling great flexibility in propelling hybrid vehicles.
To date, The Toyota Prius and Honda Insight are well known hybrid vehicles that use PST's. Applications of PST's are growing rapidly in number and variety.
The PST should not be confused with Continuously Variable Transmissions (CVT's) that use only a single source of power. PST's are capable of continuously modulating output/input speed ratios like CVT's, but they are fundamentally different devices, neither being a categorical subset of the other.
Thread
Thread Starter
Forum
Replies
Last Post