In the previous article, we have discussed the Kinematic Link, Machine element and the Kinematic pair with different classifications of the Kinematic pairs. In this article, we are going to discuss what is the Kinematic Chain.
From our previous article, the Kinematic Pair is the combination of the links or the machine elements. Likewise, the Kinematic Chain is also the combination of the Kinematic pairs.
One good example is the working of the IC Engine. The Cylinder, piston, connecting rod, crankshaft, Journal bearing in the casing. All together form the Kinematic chain.
Where the Cylinder and the piston make the first pair, piston and the connecting rod makes the second Kinematic pair, Connecting rod and the Crankshaft makes the third pair and finally, the crankshaft and the journal bearing in the crank casing makes the fourth pair.
When one of the kinematic links is fixed in a kinematic chain, then the chain is known as the Mechanism. Usually, a kinematic chain having four or less kinematic links is known as the Simple Mechanism.
A Kinematic chain having more than four kinematic links known as the Compound kinematic chain or Compound Mechanism.
What is an Inversion of a Mechanism?
As we said when we fix a Kinematic link in the Kinematic chain will make a mechanism, The Inversion of the mechanism is nothing but obtaining more mechanisms by fixing different Kinematic links in the kinematic chain.
What are the different types of Kinematic Chains?
The most important kinematic chains are those with four lower pairs. A lower pair is called when the pair is sliding or turning or screw pair.
- Four Bar Chain
- Single Slider Crank Chain
- Double Slider Crank Chain
These are the important Kinematic chains to understand. Let’s discuss them in detail.
Four Bar Chain Or Four Bar Mechanism
Four Bar chain is also is known as the Quadric Cycle chain. The four Bar chain will have four links, each of these links will form one turning pair. These four links can be of different lengths.
According to Grashof’s law for a Four bar mechanism, the sum of the shortest and the longest link lengths should be greater than the sum of the other two links.
One of the most important considerations for any mechanism is that one of the links should complete one complete revolution. Which will be the input crank for the mechanism.
In this Four bar mechanism as shown in the above gif image, It converts the rotary motion into the oscillating motion.
Single Slider Crank Chain
The Single Slider Crank Chain mechanism is nothing but the modified Four Bar mechanism. Unlike all the four turning pairs in the four-bar mechanism, The Single slider crank chain mechanism will consist of the three turning pairs and one sliding pair.
As you can see the 1.crank, 2.connecting link 3. fixed base as the fixed link 4. position moving in the crosshead are the four links. and the piston and the crosshead are making the sliding pair and the rest are making the turning pairs.
All the reciprocating Engines will be running on this mechanism only. This mechanism will convert the reciprocating motion into the rotary motion as well as the vice versa.
Double Slider Crank Chain
The name it self represent that it will have two sliding pairs and two turning pairs in the double slider crank chain mechanism.
As you can see the above picture which is an example for the Double slider crank chain mechanism. In that, We have four elements (two sliding elements, one lever, slotted one base).
The two sliding elements joined by the lever element. This liver will be making two turning pairs with the two sliding elements. The slotted base which will make the two sliding pairs with the sliding elements.
These are the different types of Kinematic chains. We have the inversion mechanisms for each of these three different mechanisms. We have discussed these in the following article.
- Four Bar Mechanism Inversions
- Single Slider crank mechanism Inversions
- Double Slider crank mechanism Inversions
We have discussed what is a kinematic chain, mechanism and Inversion of a mechanism along with the different types of the Kinematic chains such as the four-bar chain mechanism, Single slider crank chain mechanism, double slider crank chain mechanism. If you have any further thoughts on this topic, let us know in the comment section below.