Abstract: A transmission which includes input and output shafts and first and second step-down devices for producing various step-down ratios. The first and second step-down devices are associated with first and second controllable clutches, respectively, in order to connect, in a torque-transmitting manner, the respective step-down device between the input shaft and the output shaft. A first gear of the transmission is obtained by actuating the first clutch and a second gear by actuating the second clutch. A method of controlling a gearshift, from the first gear to the second gear, includes the steps of determining operating condition parameters of the transmission; and determining optimized degrees of actuation of the clutches by a search process related to a transmission model that determines the degrees of actuation on the basis of operating condition parameters in relation to a predetermined optimization criterion. The transmission model is based on slip.
Type:
Grant
Filed:
November 29, 2017
Date of Patent:
October 22, 2019
Assignee:
ZF FRIENDRICHSHAFEN AG
Inventors:
Tomas Szabo, Knut Graichen, Sebastian Hentzelt
Abstract: Arrangement of a hydraulically actuated shift actuator, comprising a shift cylinder (3), arranged outside the hydraulic control unit of a transmission is proposed, in which the shift cylinder (3) of the shift actuator is fixed on a flat or circular machined area (2) on the inside of a housing, and the side of the housing (1) facing away from the shift cylinder (3) has a flat surface (4) on which the hydraulic control unit (5) is fixed in a hydraulically leak-proof manner.
Abstract: A device for operating a shifting element of a drive mechanism, having a piston positioned in a piston space to slide between first and second end positions. The piston is operated hydraulically and depends on the hydraulic pressure in the piston space and a force of a resetting mechanism acting on the piston, which opposes the activating force that is equivalent to the hydraulic pressure in the piston space. The transmission capacity of the shifting element is reduced by a force acting on the piston in the direction of the first end position and is increased by a force acting on the piston in the direction of its second end position. The piston is held by a mechanical holder against a force acting on the piston in the direction of the first end position in at least one preset position which is different from the first end position.