Patent ID: 9067491
Filing Date: 2015-06-30
Classification: B60K,B60L,F16H,H02K,Y02T

Abstract:
1. A drive apparatus for an electric automobile, comprising: an electric motor having an output shaft; a planetary-gear transmission having a drive-side rotating shaft that is rotated and driven by the output shaft of the electric motor and a driven-side rotating shaft; and a rotation transmission apparatus for transmitting the rotation of the driven-side rotating shaft of the planetary-gear transmission to a pair of left and right drive wheels; wherein the planetary-gear transmission further comprises a first planetary-gear mechanism, a second planetary-gear mechanism, a ring gear, a first braking device and a second braking device; the first planetary-gear mechanism comprises a first sun gear that is provided in a state of being rotated and driven by the drive-side rotating shaft, a plurality of first planet gears that engage with the first sun gear, and a carrier that supports the first planet gears so as to be able to rotate and rotates and drives the driven-side rotating shaft; the second planetary-gear mechanism comprises a second sun gear, a plurality of second planet gears that are provided on the outer-diameter side and are concentric with the first planet gears, and that rotate in synchronization with the first planet gears, the same number of third planet gears as second planet gears, that are provided on the inner-diameter side and engage with the second sun gear, and a carrier that is common with that of the first planetary-gear mechanism, in which the carrier supports the second planet gears and third planet gears so as to be able to rotate freely, and in a state in which the second planet gears and third planet gears engage with each other to form a pair; the ring gear engages with the first planet gears or the second planet gears; the first braking device switches the ring gear and the second braking device switches the second sun gear respectively between a state in which rotation with respect to a fixed portion is prevented and a state in which rotation with respect to the fixed portion is allowed; and by switching the operating state of the first braking device and the second braking device, in a low-speed mode state having a large reduction ratio, the first braking device prevents the rotation of the ring gear with respect to the fixed portion, and the second braking device is released, allowing the second sun gear to rotate with respect to the fixed portion, and in a high-speed mode state, the first braking device is released, allowing the ring gear to rotate with respect to the fixed portion, and the second braking device prevents the second sun gear from rotating with respect to the fixed portion.