By Engineers, For Engineers
Choosing the right actuator is crucial for ensuring the best operation of your application. As there are various pros and cons for hydraulic, pneumatic, and electric linear actuators, the most suitable solution depends on the priorities and requirements of your application.
1. Force requirements
2. Travel speed requirements
3. Dimensional requirements
4. Environmental compatibility
5. Feedback compatibility
6. Sound/noise level
Starting the Selection Process
Choosing the right amount of force ensures that your actuator will be able to safely provide sufficient push and pull in an application. It can sometimes be difficult to estimate the required force of an actuator because of the force application angle or insufficient leverage. Calculating the required force of an actuator helps determine approximately what operating forces are required before deciding on an actuator.
In time sensitive operations, there may be a certain range of speeds that your actuator is required to have. To determine your required speed, the stroke length must be divided by the desired amount of time. For example, a stroke length of 20 inches that needs travel in a maximum of 10 seconds would mean a required speed of at least 2 inches/second.
There may sometimes be space restrictions that actuators must follow to properly fit during installation and operation. We recommend calculating the required stroke length for your application as this helps determine the required travel distance before choosing an actuator. The rest of the actuator dimensions such as width, height, and length from mounting hole to mounting hole will also need verification. Space will also need to be considered for the rest of the system and controls required to run the chosen actuator.
The lifespan of an actuator greatly depends on how suitable it is for the environment it’s been exposed to. An ingress protection, or IP rating, rates a product’s ability to withstand liquid and dust intrusion. Techniques that can help reduce water damage found in actuators include choosing the right IP rating, adding protective casing/covers and mounting the sensitive areas in a direction that’s away from the direction of approaching water. Salt spray testing is a procedure done to evaluate corrosion resistance and is also another rating to consider for applications that are in salt water or corrosive environments.
Certain applications and pre-existing systems may require actuators with a specific type of feedback to work correctly. Determining an actuator’s position is useful for applications which require multiple actuators to travel at the same speed, store preset positions and/or to collect positional information for user analysis. Improvising with a new type of feedback may sometimes be required if there are no actuators available with the same feedback type of the original system.
The sound/noise level of an operating actuator may be critical for consumer-facing applications. To determine the noise level, hold a decibel meter close to the linear actuator as it extends and retracts. Ensure this test is done in a quiet environment to avoid background noise from skewing the results and then note the highest decibel rating.
Find Your Perfect Solution
It is crucial to purchase the most suitable actuator solutions from the right suppliers. As there are various pros and cons for hydraulic, pneumatic, and electric linear actuators, the most suitable solution can depends on the priorities and requirements of your company.
1. Inherent Cost Advantage
2. Required Specifications vs. Price
3. Warranty Requirements
4. Product Downtime
5. Daily Operation Cost
6. Certifications and Safety Standards
7. Customer And Regulatory Requirements
8. Cost Savings with Increasing Volume
9. White Label Service
Starting the Selection Process
Depending on the existing tooling, infrastructure, and your current setup, one actuator solution may have an inherent cost advantage over the other. The actuator solutions with a cost advantage in this category should be noted down for consideration. For example, pneumatic solutions may have a cost advantage if the project’s existing setup already comes with access to compressed air. Another example is automotive applications which already come with 12 VDC batteries — a suitable power source for electric actuators.
Weighing the specifications and comparing them to the requirements in terms of final product price and target market segment. Deciding whether specifications or price is more important can determine which actuator solution is most suitable.
•Hydraulic actuators excel at high force, and require regular maintenance with the most infrastructure requirements.
•Pneumatic actuators excel at high speeds, also requiring regular maintenance with high infrastructure requirements.
•Electric actuators excel at meeting most general specifications while on budget constraints.
It is ideal to choose actuators from a supplier that offer the same warranty as what you’re offering for your own final product. Compare your final product’s life to the lifespan and warranty times each actuator solution offers. Make sure they align to avoid unnecessary risks if an actuator solution fails prematurely, or is not adequately covered under warranty.
Consider the impact of final product downtime on the end user. If product downtime is important, the actuator solutions that are most reliable from engineer testing should be noted down for consideration.
Calculating an actuator’s daily operation cost gives an understanding on how expensive the solution is in the long run.
Cost per day = (purchase price + maintenance cost over lifetime)* ├( (cycles per day)/(rated cycles)┤)^The actuator solutions with the best daily operation cost should be noted down for consideration.
Meeting the required certifications and safety standards is crucial for any product. It is common for actuator solutions to require UL, CE or RoHS certifications when used in industry. The actuator solutions which have the required certifications and safety standards for your final product use should be noted down for consideration.
The international standard which specifies requirements for a quality management system (QMS) is known as ISO 9001. This standard is used by organizations to demonstrate the ability to provide products and services that consistently meet customer and regulatory requirements. The actuator solutions that are ISO certified should be noted down for consideration.
Suppliers that offer staggered cost savings with increasing order volume can really benefit purchase costs in the long run. The actuator solutions that offer the most scalable cost savings with increasing volume should be noted down for consideration.
Vendors that offer white labelled units are ideal for ensuring your company can benefit from the revenue of replacement parts. The actuator solutions that offer the best program for white label service should be noted down for consideration.