Clutches, as core components of transmission systems, can be classified into the following categories based on various standards:

I. Classification by Working Principle

Embedded Clutches
Transmit torque through the interlocking of teeth, gears, or keys (e.g., tooth-type clutches). These clutches require the master/slave shafts to be stationary or operating at low speeds when engaged, making them suitable for precision transmission applications.

Friction Clutches
Use friction between the master and slave components to transmit torque, and are classified as follows:

Dry Clutches (common in manual transmissions)

Wet Clutches (multi-plate clutches with oil-immersed cooling, often used in automatic transmissions)

II. Classification by Control Method

Operated Clutches
Use external force to control engagement and disengagement, including:

Mechanical Control (cable clutches)

Electromagnetic Control (dry single-plate/multi-plate, wet multi-plate, etc.)

Hydraulic/Pneumatic Control (e.g., torque converters)

Automatic Clutches
Adapt to specific conditions:

Safety Clutches (auto-disengagement upon overload)

Centrifugal Clutches (auto-engagement upon speed threshold)

Fixed Clutches Clutch (Unidirectional transmission, such as an overrunning clutch)
III. Classification by Structural Form

Single-plate/Dual-plate/Multi-plate
Single-plate type has a simple structure (used in standard manual transmission vehicles)
Multi-plate type has a stronger load-bearing capacity (used in heavy-duty vehicles/high-performance vehicles)
Spring Type
Coil spring (circumferentially distributed)
Diaphragm spring (modern mainstream design, compact and efficient)
IV. Special Types

Electromagnetic Clutch
Includes magnetic powder clutch (adjustable current to control torque) and slip clutch (requires a master-slave speed difference to transmit force)

Hydraulic Clutch
Hydraulic torque converter transmits force through oil (now mostly used in automatic transmissions, with a vibration dampening function)