Difference between Clutch Bearing and Clutch Concentric Cylinder

It is becoming more common nowadays to come across what is known as a clutch concentric cylinder in both private cars and commercial vans and trucks. The clutch concentric cylinder is simply a slave cylinder fitted around the gearbox shaft, which does both the jobs of the traditional clutch release bearing and clutch slave cylinder.
A clutch basically disengages or isolates the drive power from the engine to the vehicle wheels momentarily while a different gear is selected. This avoids the damaging grinding together of gear cogs and provides for a smooth gear change. The clutch also allows your vehicle to stop without killing the engine.
The typical components of a traditional clutch are:
● clutch pressure plate or clutch cover
● clutch plate
● clutch fork
● clutch cable or hydraulic system and clutch bearing
● clutch flywheel
A clutch concentric slave cylinder operates immediately in line with the clutch pressure plate and allows hydraulic pressure to be transmitted to the clutch through the clutch master cylinder and then the clutch concentric slave cylinder. The advantage of using a concentric slave cylinder is that less pressure is required from the clutch pedal, and it eliminates the possibility of the traditional problems associated with excessive bearing travel due to normal wear and tear with the old link or cable systems, and being a self adjusting system it can help prolong the life of the clutch.
This system basically eliminates the need for the traditional clutch bearing and clutch fork.
It is now considered good practice to replace the concentric slave cylinder at the same time as the clutch requires replacing to avoid possible damage to the new clutch and to avoid any unnecessary further expense and time later to replace only the cylinder.
Other advantages associated with the use of a concentric clutch slave cylinder include:
● overall weight reduction (due to less components)
● longer service life (because of less moving parts)
● less prone to be affected by other external influences
● reduced maintenance costs.