Ratchet and pawl, a one-way intermittent motion mechanism consisting of ratchet and pawl.
The ratchet mechanism is commonly used in the intermittent feed of rotary or rotary tables in various machine tools and automatic machines, and is also commonly used on jacks.
In bicycles, the ratchet mechanism is used for one-way driving, and in manual winches, the ratchet mechanism is often used to prevent reversal.
The ratchet mechanism is often accompanied by noise and vibration, so its operating frequency cannot be too high.
The illustration shows an externally engaged ratchet mechanism commonly used in machinery.
It consists of active swing lever, pawl, ratchet, check pawl and frame.
The active member is sleeved on the driven shaft fixed to the ratchet and is coupled to the driving pawl by the rotating pair.
When the active member swings counterclockwise, the drive pawl is inserted into the slot of the ratchet, causing the ratchet to follow a certain angle.
At this time, the check pawl slides on the back of the ratchet.
When the active member rotates clockwise, the check pawl prevents the ratchet from rotating clockwise, while the drive pawl can slide over the back of the ratchet tooth.
Therefore, the ratchet is still at this moment.
Therefore, when the active member makes a continuous reciprocating swing, the ratchet performs a one-way intermittent motion.