Patent ID: 9744851
Date: 2017-08-29
CPC Classifications: B60K,B60Y,F16D

Claim:
1. A transfer for a four-wheel drive vehicle, the four-wheel drive vehicle including a driving source, right and left main drive wheels, a power transmission member, and right and left auxiliary drive wheels, the transfer being configured to output part of driving force, which is transmitted from the driving source to the main drive wheels, to the auxiliary drive wheels via the power transmission member when a drive mode of the four-wheel drive vehicle has been changed from a two-wheel drive mode to a four-wheel drive mode, the transfer comprising: a ring gear having a cylindrical shape, the ring gear being supported so as to rotate around a rotation axis, and configured to drive the power transmission member; an input shaft extending through an inside of the ring gear, the input shaft being supported so as to rotate concentrically with the ring gear and, configured to receive part of the driving force that is transmitted from the driving source to the main drive wheels; a disconnect mechanism configured to connect the ring gear to the input shaft and disconnect the ring gear from the input shaft, wherein an actuator configured to change the disconnect mechanism between a connection position and a disconnection position, the connection position being a position at which the ring gear and the input shaft are coupled to each other so as not to relatively rotate, the disconnection position being a position at which relative rotation between the ring gear and the input shaft is allowed, wherein the actuator includes a trip mechanism, the electromagnet and a spring, wherein the trip mechanism and the electromagnet are configured to change the disconnect mechanism between the connection position and the disconnection position, wherein the spring is configured to urge the movable meshing member from the disconnection position toward the connection position, wherein the trip mechanism includes a first piston, a second piston and a holder, wherein wherein the trip mechanism is configured to cause the second piston to move the movable meshing member to the disconnection position against the urging force of the spring by a predetermined number of times of reciprocating stroke of the first piston, and the trip mechanism is configured to, when the number of times of reciprocating stroke exceeds the predetermined number of times, unlatch the second piston and allow the movable meshing member to move to the connection position under the urging force of the spring.