BEAR-ings
By: Jordan Smallwood (Project Manager and Electronics & Control)
Approved By: Miguel Garcia (Quality Assurance)
Probably the coolest part in most mechatronic designs would have to be bearings. They’re simple but confusing and very amusing, at least for me. There are many different types of bearings in all different shapes, sizes, colors, and functionalities. The reason for this blog post is that one of the main issues with the Pathfinder build was the lack of knowledge when it came to constructing the rocker-bogie mechanism. Let me begin by saying that it is in no way previous semester’s fault for not understanding this since we are electrical engineering students.
There are two main types of bearings, thrust and radial, from those branch various specifications about each one in regards to size, forces, and speed. However, the scope of this post is to enlighten those who are concerned about which type of bearing to use.
Figure 1: Different Loads Acting on A Bearing
Thrust bearings are the type of rotary bearing that allow parts to rotate about the other but unlike their radial counterparts they are designed to support axial loads. Axial loads are forces that are applied in the direction of the shaft.
Figure 2: Example of a Thrust Bearing
Radial Bearings are the opposite and they support, wait for it, radial loads! These bearings are common and you have probably used them once or twice whether they were in your skateboard or roller blades.
Figure 3: Example of a Radial Bearing
The issue with the build of the Pathfinder is that the load on the rocker-bogie mechanism is axial and the type of bearing placed on them was a radial bearing. This radial bearing was essentially acting like a spacer between parts since they were making contact with both rotational elements. To improve the design we obtained some inexpensive thrust bearings off Amazon and they have solved the problem.
References