What is a claw shifted transmission?

Question

How is it different from an ordinary transmission? Is that a comparatively newer technology? If possible also add a few examples of motorcycles and cars which use claw shifting mechanisms.

PS: Googling did not help much. Thankyou..

Answer 1

From what I'm seeing, it's actually called a shifting claw transmission. I got this from this website:

In a shifting claw transmission for a motor vehicle including a main shaft and a countershaft and an electric motor for rotating the countershaft or being rotated thereby with freely rotatable gear wheels supported on the counter shaft and engageable with the countershaft by claw engagement structures, the speed of the countershaft is adjustable by the electric motor to be close to, but somewhat different from, the speed of the freely rotatable gear wheels to be engaged in order to facilitate shifting but avoid a tooth-on-tooth problem which would inhibit shifting.

You can also read the patent.

If you google shifting claw transmission, you'll see a bunch of options on the use portion, but it appears it's used mainly on small motorcycles. At least that is what my cursory glance gave me.

EDIT:

If you read down inside the patent, it explains the reason for the motor spun countershaft:

In a shifting claw transmission for a motor vehicle including a main shaft and a countershaft and an electric motor for rotating the countershaft or being rotated thereby with freely rotatable gear wheels supported on the counter shaft and engageable with the countershaft by claw engagement structures, the speed of the countershaft is adjustable by the electric motor to be close to, but somewhat different from, the speed of the freely rotatable gear wheels to be engaged in order to facilitate shifting but avoid a tooth-on-tooth problem which would inhibit shifting.

The motor's main purpose is to spin the countershaft. While spinning it, it ensures the speed of the countershaft is a somewhat different speed than the main shaft. This allows the gears to mesh without the need for a synchronizer (or synchro for short). Further it explains:

Utility vehicle transmissions with shifting claws have a long service life and a high level of reliability because there are no frictional synchronization means which are subjected to wear. Furthermore, shifting claws are more cost-effective than blocking synchronous rings. The problem which is associated with omitting blocking synchronous rings, is that, in rare cases, the shifting tooth or claw arrangements of the shifting claw clutch can be in a tooth-on-tooth position preventing shifting, particularly when the vehicle is not moving.

Not only is it cheaper to produce than a synchro transmission, it should also last longer.