Introduction and principle of crank slider technology

The crank slider mechanism, as a commonly used mechanism in machinery, is mainly used to convert continuous rotation into reciprocating motion or to convert reciprocating motion into continuous rotation. It is widely used in machinery such as automatic feeding mechanisms, punches, and internal combustion engines.
operational principle
A planar linkage mechanism that uses a crank and a slider to convert rotation and movement, also known as a crank linkage mechanism. The component that forms the moving pair with the frame in the crank slider mechanism is the slider, and the component that connects the crank and slider through the rotating pairs A and B is the connecting rod (Figure 1). When the mechanism moves, if the trajectory of hinge center B does not pass through the rotation center OA of the crank, it is called an offset crank slider mechanism (Figure 1a), where e is the offset. If different components are taken as frames, a rotating guide rod mechanism (Figure 1b), a crank rocker mechanism (Figure 1c), and a moving guide rod mechanism (Figure 1d) can be obtained. If the guide rod and slider in the crank rocker mechanism are exchanged again, the swinging guide rod mechanism is obtained (Figure 1e). If the trajectory mm of slider B passes through OA, it is called the centering crank slider mechanism (Figure 2).
The crank slider mechanism is widely used in the main structures of reciprocating piston engines, compressors, punches, etc., to convert reciprocating movement into incomplete or complete rotational motion; Compressors and punches use cranks as the driving components to convert full cycle rotation into reciprocating motion. The slider of the offset crank slider mechanism has a quick return characteristic, and the saw machine uses this characteristic to achieve the purpose of slow advance and idle quick return of the saw blade.
In the centering crank slider mechanism (Figure 2), when OA=AB, except for the motion trajectory of point D (AD=AB) which is a straight line, all other points on the connecting rod move along the elliptical trajectory. This mechanism is also known as an ellipsometer.
The motion characteristics of the crank slider are commonly represented by the relationship curve between the crank angle and the slider stroke s (Figure 3). If it is a centering crank slider mechanism, there is no quick return characteristic, and the angle between the extreme positions is zero.