Patent ID: 8562464
Filing Date: 2013-10-22
Classification: F16H

Abstract:
1. A multi-stage transmission with at least two parallel continuously variable transmission (CVT) devices, comprising: a low shift different-shaft-type CVT device having a low shift driving pulley and a low shift driven pulley, said low shift driving pulley and low shift driven pulley having a first continuously variable speed ratio; at least a high shift different-shaft-type CVT device having a high shift driving pulley and a high shift driven pulley, said high shift driving pulley and high shift driven pulley having a second continuously variable speed ratio; an input shaft connected to the low shift driving pulley and the high shift driving pulley; an output shaft connected to the low shift driven pulley of the low shift different-shaft-type CVT device; a clutch device for selectively engaging and disengaging the high shift driven pulley of the high shift different-shaft-type CVT device and the output shaft; and a unidirectional transmission device or torque-limiting clutch device connected between one of the input shaft and output shaft and a respective one of the low shift driving pulley and the low shift driven pulley, wherein at low speeds or loads, the clutch is open to disengage the high shift driven pulley high shift different-shaft-type CVT device and drive the output shaft exclusively through the low shift CVT device, and when the low shift CVT device is a deceleration type CVT device operated at or close to a minimum deceleration ratio or an acceleration type CVT device operated at or close to a maximum acceleration ratio, then when a rotational speed of the output shaft reaches or exceeds a predetermined speed, the clutch is closed to connect the high shift driven pulley and the output shaft such that said output shaft is driven at a speed ratio of the high shift transmission device.