Patent ID: 6283883
Filing Date: 2001-09-04
Classification: F16H

Abstract:
A power transmission system that includes a rotatable and drivable first shaft which is adapted for coaction with a motor that forms part of a planetary gear arrangement, and a second shaft which is driven by said arrangement, wherein a planet gear belonging to the planet gear arrangement includes a centrally positioned sun gear that coacts with said first shaft, a number of planet gears able to coact with said sun gear, a ring gear coacting with said planet gears, and a gear holding said planet gears, and wherein an hydraulic system forming part of the planetary gear arrangement includes a pump unit and a motor unit, among other things, and wherein the ring gear belonging to the planetary gear mechanism can be braked via a first coupling unit and therewith held stationary relative to a chassis in a low speed range while being freed for rotation in a high speed range, wherein in the low speed range the hydraulic system functions to drive the second shaft with the pump unit and the motor unit but provides a split-torque function in the high speed range, characterized in that the first shaft is adapted to rotate the sun gear; in that said hydraulic pump unit is coupled directly or indirectly to the gear holding said planet gears; in that said hydraulic motor unit is coupled directly or indirectly to the second shaft; in that a second coupling unit functions to co-ordinate the rotary movement of the ring gear with the pivotal movements of the hydraulic motor in the high speed range; and in that the first coupling unit is adapted to act between a chassis and a gear co-acting with the ring gear; and in that the second coupling unit is adapted to act between a gear co-acting with said motor unit and the gear co-acting with said ring gear for common rotary movement and rotation of the second shaft.