1, Parallelogram mechanism
below Figure (a), the parallelogram mechanismABCD< /em>, the two opposite poles have the same motion law. Active crank1When turning counterclockwise, it drives the driven lever3 rotates in the same direction and speed, and the feed rod2translates to move the material< /strong>4Move forward one step at a time. Parallelogram mechanisms are widely used, such as train wheel linkage mechanisms, multiple sets of parallelogram couplings, drawing instruments, and zooming mechanisms.
2. Parallelogram mechanism with multiple output shafts
belowadrive crank1When it rotates, it drives the disc2to move in translation, thereby driving four equal-length cranks at the same time 3Each rotates at the same speed around its own fixed axis. This mechanism allows a smaller main and driven axle wheelbase. This mechanism can be applied to multi-head drilling, multi-head milling, etc. When the speed is high, attention should be paid to the balance. Figureb is an example of the structure of a long diamond. Active eccentric shaft2through disc3 Drive and 2same eccentricityedrill pipe4 turn.
3. Two-wheelbase variable parallelogram mechanism
Disk below2, strong>4, 6 have three equally spaced The pins are hinged to each other by three connecting rods with a length of l to form multiple parallelogram mechanisms (Figurea). The rotation of the driving shaft1 makes the driven shaft 7< /span> to rotate at the same speed. This mechanism can change the distance between the main and driven shafts during operation (the maximum wheelbase is 2l em>, the maximum displacement of the driven axis is 4l< span>, figureb, c, d). During operation, the center of the disc 4 has a constant and definite position, only when the master and slave axes coincide (zero displacement position, Fig. < /span>d), disk 4 is in indeterminate position state, so this location should be avoided.
The rest of the structure is described in the next section.