Double Slider crank Mechanism consists of two sliding pairs and two turning pairs.
Inversions of Double slider crank Mechanism
- Elliptical trammel Mechanism
- Scotch yoke mechanism
- Oldham’s coupling Mechanism
1. Elliptical Trammel Mechanism
Elliptical Trammel is an instrument used for drawing ellipses. An elliptical trammel (also known as Trammel of Archimedes) is used to draw the ellipses of various sizes. It is an inversion of double slider crank chain in which there are two sliding pairs and two turning pairs. Slider 1 (Link 4) moves vertically while slider 2 (Link 2) moves horizontally. The frame is kept fixed (Link 1).
2. Scotch yoke Mechanism
Scotch Yoke mechanism is used for converting rotary motion into a reciprocating motion. The inversion is obtained by fixing either the link 1 or link 3. In, link 1 is fixed. In this mechanism, when the link 2 (which corresponds to crank) rotates about B as center, the link 4 (which corresponds to a frame) reciprocates. The fixed link 1 guides the frame.
3. Oldham’s Coupling Mechanism
An oldham’s coupling Mechanism is used for connecting two parallel shafts whose axes are at a small distance apart. The shafts are coupled in such a way that if one shaft rotates, the other shaft also rotates at the same speed. This inversion is obtained by fixing the link 2. The shafts to be connected have two flanges (link 1 and link 3) rigidly fastened at their ends by forging.