How to avoid design compromises when the equipment function calls for cam followers
Engineering design is an art of compromise. To achieve a design goal — for example, a certain machine function — engineers select components based on several criteria such as functionality, reliability, component’s availability, cost, and lead times. Pro and cons are analyzed and final selection made.
In the case of cam followers, in the past engineers did not have a choice other than selecting the manufacturer. With few options available, the engineers were forced to accept a host of costly requirements and operational limitations.
Whether the application calls for high or low load capacity, the design has to provide for lubrication either manually or through a central lubrication system. Rail or cam surfaces have to be hardened. In operation, lack of lubrication of the bearing or the rail surface can lead to a catastrophic failure. Over-greasing can lead to the cam follower’s skidding, causing wear, and excess grease can contaminate the product being processed.
In addition, shock and vibration can cause metal to metal impact that has to be considered. Metal particles and grease contamination often prevent equipment manufacturers from entering the growing clean room market. The relatively low rotating speed of needle bearings, their high rolling resistance, and inertia may be limiting factors in high speed equipment design.
When selecting Intech iCamFollowers® the designer can eliminate most of the disadvantages of metal cam followers. This is especially the case in designs where the cam follower’s primary function is to transmit motion and not its high load carrying capacity.
Today the trend is toward high speed, light weight, and light duty machines in processing, packaging, medical, and semi-conductor machines, which account for about 40 percent of applications. In these applications, Intech iCamFollowers® can easily carry the load, help simplify design, and better achieve the design goal.
Considering the cost associated with design and operation of metal cam followers, it pays to better understand the actual load carried by the cam followers in the application. With load data, including radial and axial forces, load duty cycle, and desired linear speed, Intech engineers can use a unique plastic roller life calculation to quickly assess whether an iCamFollower can be used.
The load capacity of Intech standard iCamFollowers® is listed on Intech’s web site and represents the maximum load the cam followers can safely carry for 100 million cycles, under both static and dynamic loads, without developing a flat or excessive wear. A consultation with Intech engineers may lead to an alternative designs, opening the way to eliminating wear and lubrication as well as the number of modifications in the machine’s design.
If iCamFollowers® can be used, the advantages, compared to metal followers are many:
For New Equipment:
* Simplified design- cost savings
* No need for surface hardening- can run on aluminum rails
* No rail or cam wear
* No need for lubrication- manual or automatic
* Higher machine speed- Lower inertia, low rolling resistance
* Shock absorption
* Wash Down- stainless steel bearings and shafts, sealed design
* Sub-zero temperatures
* Elimination of lubrication and metal particles can open new markets
In plant Operations:
* Eliminating Lubrication
* Eliminating rail and cam wear
* Cost savings on maintenance
* Cost savings on production shortfall
* Longer maintenance cycles
* Noise reduction
* Low cost to try if iCams work
Credits: As featured in Design World May 9 2011. http://www.designworldonline.com/how-to-avoid-design-compromises-when-the-equipment-function-calls-for-cam-followers/#_