Patent ID: 7524257
Filing Date: 2009-04-28
Classification: F16H

Abstract:
1. A vehicular planetary gear type step-variable transmission comprising: a first transmission portion and a second transmission portion which are disposed coaxially with a first axis, and wherein a rotary motion of an input rotary member rotated by a drive power source about the first axis is transmitted from said first transmission portion to said second transmission portion through a first intermediate output path, and a second intermediate output path a rotation motion of which is decelerated with respect to the rotary motion of said input rotary member at a speed ratio higher than that of said first intermediate output path, and a rotary motion of an output rotary member rotated about said first axis is transmitted to a drive wheel of a vehicle; said first transmission portion including a first planetary gear set of a double-pinion type having a first carrier connected to said input rotary member and said first intermediate output path, a first ring gear connected to said second intermediate output path, and a first sun gear fixed to a stationary member; said second transmission portion including a second planetary gear set of a single-pinion type having a second sun gear, a second carrier and a second ring gear, and a third planetary gear set of a double-pinion type having a third sun gear, a third carrier and a third ring gear, said second sun gear being selectively connected through a fourth clutch to said first intermediate output path, selectively connected through a third clutch to said second intermediate output path, and selectively fixed through a first brake to said stationary member, said second carrier and said third carrier being constituted by a common member, selectively connected through a second clutch to said first intermediate output path, and selectively fixed through a second brake to said stationary member, said second ring gear and said third ring gear being constituted by a common member and fixed to said output rotary member, and said third sun gear being selectively connected through a first clutch to said second intermediate output path; and a power transmitting member is disposed rotatably about a second axis parallel to said first axis and operatively connected to said output rotary member, for transmitting the rotary motion of said output rotary member to said drive wheel, said vehicular planetary gear type step-variable transmission being installed on the vehicle such that said first axis and said second axis are parallel to a width direction of the vehicle.