Power transmission apparatus, four-wheel drive vehicle with power transmission apparatus incorporated therein, method of transmitting power, and method of four-wheel driving

A four-wheel-drive vehicle for transmitting power independently to a first axle and a second axle of said vehicle, said four-wheel-drive vehicle comprising:

• an engine having a rotating shaft, from which power is taken out, said engine rotating said rotating shaft;
• a first motor related to rotation of said rotating shaft;
• distribution means for regulating distribution of power input to said rotating shaft, power input to and output from said first axle in a mechanical form and power input to and output from said first motor in an electrical form, in such a manner as to balance a total input power with a total output power;
• a second motor linked with said second axle;
• first power control means for controlling the power input to and output from said first motor in the electrical form, thereby varying a driving state of said first motor and controlling the distribution of the power executed in said distribution means;
• and
• second power control means for controlling operation of said second motor based on the power input to and output from said first motor in the electrical form by said first power control means, thereby regulating power output to said second axle.

A four-wheel-drive vehicle comprising a power transmission apparatus for transmitting power of an engine to a first axle of said vehicle and a second axle, which is not in direct mechanical connection with said first axle, said four-wheel-drive vehicle comprising:

• said engine having a rotating shaft for outputting the power, said engine rotating said rotating shaft;
• a first motor comprising a first rotor mechanically linked with said rotating shaft of said engine and a second rotor electromagnetically connected with said first rotor so as to rotate relative to said first rotor, said second rotor being mechanically linked with said first axle;
• a first motor-driving circuit for controlling electromagnetic connection between said first rotor and said second rotor in said first motor by multi-phase alternating current, so as to enable transmission of electric power between said first motor-driving circuit and said first motor at least in one direction;
• a second motor comprising a third rotor mechanically linked with another rotating shaft of said engine and a fourth rotor electromagnetically connected with said third rotor so as to rotate relative to said third rotor, said fourth rotor being mechanically linked with said second axle;
• a second motor-driving circuit for controlling electromagnetic connection between said third rotor and said fourth rotor in said second motor by multi-phase alternating current, so as to enable transmission of electric power between said second motor-driving circuit and said second motor at least in one direction;
• and
• power distribution control means for controlling said first motor-driving circuit and said second motor-driving circuit, thereby enabling the power of said engine to be output to said first axle and said second axle at a predetermined distribution ratio.

A four-wheel-drive vehicle comprising a power transmission apparatus for transmitting power of an engine to a first axle and a second axle of said vehicle, said four-wheel-drive vehicle comprising:

• said engine having a rotating shaft for outputting the power, said engine rotating said rotating shaft;
• a first motor comprising a first rotor mechanically linked with said rotating shaft of said engine and a second rotor electromagnetically connected with said first rotor so as to rotate relative to said first rotor, said second rotor being mechanically linked with said first axle;
• a first motor-driving circuit for controlling electromagnetic connection between said first rotor and said second rotor in said first motor by multi-phase alternating current, so as to enable transmission of electric power between said first motor-driving circuit and said first motor at least in one direction;
• a second motor linked with said second axle, which is not in direct mechanical connection with said first axle;
• a second motor-driving circuit for enabling transmission of electric power between said second motor-driving circuit and said second motor at least in one direction;
• and
• braking force control means for controlling said first motor-driving circuit and said second motor-driving circuit, thereby giving a braking torque to said first axle and/or said second axle.

A method of controlling distribution of power input from an engine via a rotating shaft into a power allocation input to and output from a first output shaft connected to a first motor and a power allocation input to and output from a second output shaft which is different from said first output shaft and linked with a second motor, said method comprising the steps of:

• providing distribution means for regulating distribution of the power input to said rotating shaft, the power input to and output from said first output shaft in a mechanical form, and power input to and output from said first motor in an electrical form, in such a manner as to balance a total input power with a total output power;
• controlling the power input to and output from said first motor in the electrical form, thereby varying a driving state of said first motor and controlling the distribution of the power executed in said distribution means;
• and
• controlling operation of said second motor based on the power input to and output from said first motor in the electrical form through the operation of said distribution means, thereby regulating the power output to said second output shaft.

A method of controlling four-wheel-drive, said method controlling distribution of power input from an engine via a rotating shaft into a power allocation input to and output from a first axle connected to a first motor and a power allocation input to and output from a second axle which is different from said first axle and linked with a second motor, said method comprising the steps of:

• providing distribution means for regulating distribution of the power input to said rotating shaft, the power input to and output from said first axle in a mechanical form, and power input to and output from said first motor in an electrical form, in such a manner as to balance a total input power with a total output power;
• controlling the power input to and output from said first motor in the electrical form, thereby varying a driving state of said first motor and controlling the distribution of the power executed in said distribution means;
• and
• controlling operation of said second motor based on the power input to and output from said first motor in the electrical form through the operation of said distribution means, thereby regulating the power output to said second axle.