| 摘要 |
A device and a method for continuously variable transmission, wherein a variable displacement pump (1) and two variable displacement motors (2, 3) are connected to each other through a closed circuit. A first drive gear (6) to a fourth drive gear (9) are fitted to the motor shafts (18, 19) of the variable displacement motors (2, 3) through clutches (13a, 13b) and clutches (14a, 14b). A first driven gear (10) meshed with the first drive gear (6) and the third drive gear (8) and a second driven gear meshed with the second drive gear (7) and the fourth drive gear (9) are fitted to an output shaft (4). The equivalent capacities of the variable displacement motors (2, 3) are differentiated from each other, and a control to zero these capacities is performed in the descending order of the equivalent capacities. When the capacity of the variable displacement motor is decreased, the gear ratio of the variable displacement motor with a capacity reduced to zero is changed to reduce the equivalent capacity, and the capacity is increased to the maximum one. Thus, since the gear ratio of continuously variable transmission can be increased, a speed increasing control by increased continuously variable transmission can be performed. ® KIPO & WIPO 2008
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