1/2 Gear Synchronizer 12JS160T-1701170

Since the input and output shafts of the transmission rotate at different speeds, there is a "synchronization" problem when changing gears. If two gears with different rotational speeds try to mesh together forcibly, it will inevitably cause impact and collision, damaging the gears. Therefore, in old-style transmissions, gear shifting was done using the "two-foot clutch" method. When upshifting, it was necessary to stay in the neutral position for a moment, and when downshifting, the accelerator should be pressed in the neutral position to reduce the speed difference between the gears. However, this operation is rather complicated and difficult to master precisely. Therefore, designers created "synchronizers" to make the gears to be meshed reach the appropriate rotational speed and then mesh smoothly.

The full-synchronous transmission uses an inertia synchronizer, which is mainly composed of the engagement sleeve, the synchronizer lock ring, etc. Its characteristic is that it achieves synchronization through friction. The engagement sleeve, the synchronizer lock ring and the gear ring of the gear to be engaged all have chamfers (locking stop angles). The inner conical surface of the synchronizer lock ring contacts the outer conical surface of the gear ring of the gear to be engaged, generating friction. The locking angle and the conical surface have been appropriately selected during design. The conical surface friction causes the engaged gear and the gear ring to synchronize rapidly, and at the same time, it generates a locking effect to prevent the gears from engaging before synchronization.

After the inner conical surface of the synchronizer lock ring contacts the outer conical surface of the gear ring to be engaged, under the action of the frictional torque, the gear speed rapidly decreases (or increases) to be equal to the speed of the synchronizer lock ring. Both gears rotate synchronously, and the rotational speed of the gear relative to the synchronizer lock ring is zero. Thus, the inertial torque also disappears at this time. Under the push of the action force, the engagement sleeve is not hindered and is joined with the synchronizer lock ring gear ring, and further joined with the gear ring of the gear to be engaged to complete the shifting process.