Patent ID: 8977455
Filing Date: 2015-03-10
Classification: F16H,Y10T

Abstract:
1. A power transmission apparatus comprising: a drive shaft; a driven shaft; a first transmission device to change power of the drive shaft; a first one-way power transmission mechanism which transmits power changed by the first transmission device only in one direction to the driven shaft if a rotational speed of the drive shaft exceeds a rotational speed of the driven shaft and which does not transmit drive force if the rotational speed of the drive shaft is less than the rotational speed of the driven shaft; a second transmission device to change power of the driven shaft; a second one-way power transmission mechanism which transmits power changed by the second transmission device only in one direction to the drive shaft if a rotational speed of the driven shaft exceeds a rotational speed of the drive shaft and which does not transmit drive force if the rotational speed of the driven shaft is less than the rotational speed of the drive shaft; and a controller configured to change ratios of the first transmission device and the second transmission device, a ratio of the first transmission device being calculated by dividing the rotational speed of the drive shaft by the rotational speed of the driven shaft, a ratio of the second transmission device being calculated by dividing the rotational speed of the drive shaft by the rotational speed of the driven shaft, the controller being configured to control the ratios of the first transmission device and the second transmission device such that the ratio of the first transmission device is larger than the ratio of the second transmission device.