market dynamics
Analysis of working principle of motorcycle sliding clutch
Release date:2021.02.08

Assist & Slipper Clutch, also known as Reverse Torque Limiter Clutch, "Sliding Clutch" for short. It is not a necessary component of the motorcycle, but usually exists in the form of optional parts or upgraded parts. It is more and more popular in the modern motorcycle. It is generally considered to be a manifestation of a highly equipped model. At present, there is no lack of standard models with sliding clutch in domestic high-end motorcycles.

The main purpose of assembling sliding clutch is to avoid the negative impact of the "engine braking force", eliminate the wheel vibration or pulsation phenomenon in the case of emergency braking and gear downshift, and maintain the stability of driving.

When the vehicle with traditional clutch is in emergency braking and fast down gear operation in the process of running, it is easy to have the rear wheel flutter or jump, which may lead to the rear wheel lock. If this problem occurs before entering the corner, it is very likely to cause a vehicle toppling accident.

This is because, snap to slow down and reduce operation, speed ratio of the rear wheel and the engine is changed in an instant, within the engine to form the strong "reverse torque", is a common your "engine", by chain transmission to the rear wheels, lead to the rear wheels wobble, vibrate or beating, eventually lose traction and grip. Generally speaking, the larger the displacement, the longer the piston stroke of the engine, the stronger the engine braking force will be.

The other effect of the sliding clutch is that it can make the clutch and pull rod very light, just one finger can easily pull and pinch the pull rod, and complete the shift operation.


The working principle of sliding clutch

Before understanding how sliding clutches work, let's take a look at the internal composition of traditional and sliding clutches.

1. The composition and working principle of traditional clutch

The power generated by the reciprocating motion of the piston is converted into rotating motion through the crankshaft, and the power is transferred by the power flywheel to the clutch assembly, which transfers the power to the input shaft of the gearbox, which is transferred after meshing with different gears (shifting gears)

In the whole process of power transmission, the clutch plays a vital "bridge" role.

The traditional clutch assembly includes outer hub (big drum), clutch plate (steel plate + friction plate), inner hub (small drum), pressure plate and spring and other 5 parts.

The axis of the inner hub is aligned with the input shaft of the gearbox, and maintains connection and rotation at the same speed; The outer hub is always engaged with the crankshaft flywheel, and maintains the same rotation.

A number of clutch plates are stacked between the inner and outer hubs, which are composed of steel plates and friction plates respectively. The steel sheet is in series with the outer hub shaft, and the friction sheet is in series with the inner hub shaft. The steel sheet is the driving piece, and the friction sheet is the driven piece. Before the power is not engaged, the outer and inner hub and its attachment do not interfere with each other and rotate at different speeds.

When pulling and pinching the clutch rod, the clutch spring will push the pressure plate to the outside, the steel sheet and friction sheet are separated, the gearbox and the engine power are separated, and the shift operation can be carried out; When release slowly release the clutch lever, spring back elastic clamp to internal pressure tight, different rotation speed of sheet steel and slowly contact friction plate, friction, and drive their attached parts (connected to the outside, inside the hub of institutions (including outside the hub gear, crankshaft, flywheel and transmission input shaft) rotation speed to the same speed, eventually clutch plate joint to one, and each card into the inside outside the hub and the hub lock in the card slot, outside, inside the hub assembly complete dynamic joint.

2. The composition and working principle of sliding clutch

The components of sliding clutch are basically the same as that of traditional clutch. But there is one of the biggest differences between the phase, is that the outer, inner hub internal structure is completely different. Please see the following figure, the outer and inner hub of the sliding clutch have adopted the "ramp" convex block design, which can slide interlock or slide out of each other.

The principle of power engagement and separation is basically the same as that of traditional clutch. Its most key beauty is that at the moment when the "engine braking force" comes into effect, the inner hub assembly will slide away from the outer hub assembly with the help of the "ramp", resulting in the separation of the gearbox and the engine power, effectively eliminating the phenomenon of rear wheel chatter.

The rear-wheel to engine RPM will return to normal in a relatively short time. When the throttle is opened again, the inner hub assembly is easily slid into the outer hub "ramp" with the help of the "ramp" block. With the increase of the speed, the faster the sliding speed, the more tightly the outer and inner hub assembly is combined. In fact, "ramps" Assist. With the aid of the "ramp", the compression and rebound forces of the plate spring can be set to as small a value as possible. This is the main reason why the sliding clutch pull rod is very brisk.