Power-shift transmission with continuously variable mechanical actuating mechanism

摘要

The invention relates to a power-shift transmission which comprises an actuating coupler mechanism and a shift transmission. Two shafts of the three-shaft epicyclic mechanism of the actuating coupler mechanism are coupled via a continuously variable cone-pulley mechanism and drive the shift transmission primarily in alternation. A gear change of the power-shift transmission, which acts like a continuously variable transmission with a large operating range, is accomplished without an interruption in the tractive effort, without slip and with synchronism of the speeds of rotation. All the gear stages required as a reduction gear mechanism in the actuating coupler mechanism also assume functions in the shift transmission. This results in a saving of gears in comparison with known solutions and this has an advantageous effect as regards overall size, weight, efficiency and manufacturing effort and costs. In a special operating condition, the entire power flows via one tooth engagement less than would otherwise be the case. There are design-dependent operating points at which the actuating mechanism can be bridged and the entire power is transmitted approximately with the efficiency of one gear stage. At these operating points, either the epicyclic mechanism revolves as a clutch or the power flows via two transmission stages driven by different epicyclic mechanism shafts to the main output. The epicyclic mechanism preferably has a stationary transmission ratio of io = -1 and the actuating mechanism and the actuating coupler mechanism are designed for maximum efficiency or minimum actuating power flow.