Some Information about Free Wheel Hubs

The original four-wheel drive model was designed to meet the requirements of normal driving in complex road conditions. The automatic hub is an important element used in time-sharing four-wheel drive vehicles. There are two types of engaging hub systems, one Manual type, and the other automatic type. Automatic locking - the free hub uses the rotation of the drive shaft to automatically engage the hub, when the cam disc is activated, the sliding gear slides along the drive gear, completing the free locking between the drive shaft and the hub - free operation. Thanks to the automatic hub, the front wheel can rotate freely, while the front drive shaft, differential gear, and transmission shaft remain stable, which reduces unnecessary wear between these components and saves fuel.

Structure 

The automatic locking-free hub is designed so that the cam plate can be activated by the rotation of the half shaft, the cam plate works, and then the sliding gear slides along the driving gear, which makes the hub and the half shaft complete the automatic locking-free operation. Rotation of the half shaft is detected by a raised portion on the drive disc, which rotates together with the half shaft and the thrust disc held on the side of the knuckle shaft.

Working principle

Freehub in the "FREE" position

The automatic hub is in the "FREE" position, the sliding gear is separated from the driving gear, the hub housing and the sliding gear, the positioning bracket, and the fretting spring rotate with the wheel as a whole; the drive shaft, drive gear, hub cap, etc. are stationary.

The transition from "FREE" to "LOCK" position

The rotation of the drive shaft is transmitted to the drive gear, and the drive gear drives the drive to rotate; the drive disc rotates the elastic drive ring, and then drives the thrust disc; at this time, the protruding part of the cam disc is removed from the groove of the thrust disc under the action of the thrust disc. is pushed out; the movement of the cam disc makes the sliding gear move under the action of the cam, the inner teeth are connected to the drive gear, and the outer teeth mesh with the housing; the automatic hub changes from the "FREE" (free) position to the "LOCK" (locking) position; When the automatic hub is in the "LOCK" position, the drive shaft, drive gear, drive disc, cam disc, sliding gear, thrust disc, elastic drive ring, and hub housing rotate as a whole, and the hub cover does not occur under the action of the steering knuckle turn.

When the free hub is in the "LOCK" position

When the free hub is in the "LOCK" position, the rotation of the drive shaft is transmitted to the wheels.