Overrunning bi-directional clutch as gear synchronizer and coupler

1. A gear synchronizer comprising:

a transmission shaft for interconnecting at least two gears in a transmission;

an overrunning bi-directional clutch including a split outer shell and a plurality of needle rollers with respective distal ends, radially disposed between the outer shell and the transmission shaft;

an actuator pin extending through the shaft and engageable with the outer shell at a position located axially between two radial planes extending from the needle roller distal ends to limit relative rotation between the outer shell and the transmission shaft; and,

a rotating drum internal to the power transmission shaft and including cam lugs for rotating the actuator pin,

wherein the actuator pin includes an axis and is rotated about its axis between a free position for the synchronizer and a locked position for the synchronizer.

2. The gear synchronizer of claim 1 further comprising a gear, wherein the outer shell is arranged to radially expand to facilitate torque transmission between the transmission shaft and the gear.

3. The gear synchronizer of claim 2 wherein the outer shell or the transmission shaft includes a plurality of ramps for receiving the plurality of needle rollers.

4. The gear synchronizer of claim 3 wherein relative rotation between the outer shell and the transmission shaft urges the needle rollers up the ramps to radially expand the outer shell.

5. The gear synchronizer of claim 1 further comprising an inner shell engaged with the transmission shaft, wherein:

the plurality of needle rollers are radially disposed between the outer shell and the inner shell; and,

the outer shell or the inner shell includes a plurality of ramps for receiving the plurality of needle rollers.

6. The gear synchronizer of claim 1 wherein the cam lugs contact the bottom of the actuator pin.