Patent ID: 8441161

Claim:
An electric motor drive device comprising a motor, a speed reducing part to reduce speed of a rotation outputted from said motor and transmit it to the side of a wheel, and a connection/disconnection part to disconnect or connect rotation transmission of said speed reducing part, wherein said speed reducing part has an input shaft to input the rotation from the motor, an output shaft to output the rotation to the side of the wheel, a double shaft arranged coaxially with the one of said input shaft and said output shaft and including a tube-shaped outer side rotation shaft and an inner side rotation shaft inserted into said outer side rotation shaft, an opposite-side shaft connected to the other one of said input shaft and said output shaft, a first speed reducing part including a plurality of rotation elements to reduce speed of the rotation on the side of the motor with a first speed reduction ratio, between one of said outer side rotation shaft and said inner side rotation shaft, and said opposite-side shaft and transmit it to the side of the wheel, and a second speed reducing part including a plurality of rotation elements to reduce the speed of the rotation on the side of the motor with a second speed reduction ratio different from said first speed reduction ratio, between the other one of said outer side rotation shaft and said inner side rotation shaft, and said opposite-side shaft and transmit it to the side of the wheel, and said connection/disconnection part has an inner side rotation shaft clutch to disconnect or connect rotation transmission between said inner side rotation shaft and said input shaft or said output shaft coaxially arranged with each other, and an outer side rotation shaft clutch to disconnect or connect rotation transmission between said outer side rotation shaft and said input shaft or said output shaft coaxially arranged with each other.