Control device of power transmission device, power transmission device, and control method for power transmission device

A power transmission device comprising:

• an input shaft;
• an output shaft;
• a differential device including
• a first rotation element connected to the input shaft,
• a second rotation element connected to the output shaft, and
• a third rotation element;
• a continuously variable transmission unit including
• a conversion unit configured to convert a first rotational power of the third rotation element into a first other power and
• a reconversion unit configured to reconvert a second other power into a second rotational power and supply the second rotational power to the output shaft;
• and
• a control device configured to
• determine whether a target traction force of the output shaft is larger than a traction force that the power transmission device is capable of exerting, and
• upon determining that the target traction force is larger than the traction force that the power transmission device is capable of exerting, generate a control signal of the continuously variable transmission unit such that the first other power generated by the conversion unit exceeds the second other power input to the reconversion unit.

A control method for a power transmission device that includes

• an input shaft,
• an output shaft,
• a differential device including
• a first rotation element connected to the input shaft,
• a second rotation element connected to the output shaft, and
• a third rotation element, and
• a continuously variable transmission unit including
• a conversion unit configured to convert a first rotational power of the third rotation element into a first other power and
• a reconversion unit configured to reconvert a second other power into a second rotational power and supply the second rotational power to the output shaft,
• the method comprising:
• determining whether a target traction force of the output shaft is larger than a traction force that the power transmission device is capable of exerting, and
• upon determining that the target traction force is larger than the traction force that the power transmission device is capable of exerting, generating a control signal of the continuously variable transmission unit such that the first other power generated by the conversion unit exceeds the second other power input to the reconversion unit.