Performance comparison of Linear Oscillating Actuators with Rare-Earth and Ferrite magnets
Linear Actuators are electromechanical devices which provide bidirectional motion in a single axis for a specific load without any screws, gears, or crankshafts. They are characterized by the absence of mechanical energy conversion system, which results in fast response, high dynamic performance, an
2025-06-28 16:34:26 - Adil Khan
Performance comparison of Linear Oscillating Actuators with Rare-Earth and Ferrite magnets
Project Area of Specialization Electrical/Electronic EngineeringProject SummaryLinear Actuators are electromechanical devices which provide bidirectional motion in a single axis for a specific load without any screws, gears, or crankshafts. They are characterized by the absence of mechanical energy conversion system, which results in fast response, high dynamic performance, and high reliability. Meanwhile due no end windings and high permanent magnet (PM) utilization, tubular linear actuators have the advantages of high air-gap flux density and high efficiency compared to flat linear actuators
Linear Oscillating Actuator (LOA) consist of two main parts, called stator and mover. The stator, actuator’s stationary part, generates a controlled electromagnetic energy. This energy is transformed into mechanical work by displacing the armature (moving part) to the position where the magnetic flux faces the least reluctance. On the basis of moving part (mover) configuration there are three types of LOA which are moving iron, moving coil and moving magnet. The applications of the proposed LOA are automation, circuit breakers, biomedical aerospace industries and compressor for refrigerator system
The main purpose of this project is to investigate the performance of moving magnet LOA using Ferrite and rare earth magnet with tubular structure and then their performance for compressor application
Project ObjectivesThe whole world is facing energy crisis in the power sector. Due to high value and lack of availability of energy, currently the attention of saving energy is prominent. Saving energy of household instrument especially refrigerator which consumes 20 to 40 percent of electrical energy in a house. In refrigerator, the large amount of energy is consumed in compressor. A compressor of high efficiency can save large amount of energy. Using LOA in compressor of refrigerator can utilize energy in efficient manner and it is very cost effective and has better outputs as compared to rotatory mechanism.
The main Objectives of this project are:
- To design and analyzed moving magnet LOA (using rare earth and ferrite magnets) with high efficiency and power density and then compared their performance]
- To fabricate both moving magnets LOA and analyze their outputs.
- To validate the simulation results of both LOA experimentally, compared and finally proposed the best one for compressor application.
The project implementation is divided it into three parts given below.
- COMSOL Simulation
- Fabrication
- Experimental result and Comparison
COMSOL Multiphysics is the software package used to design and evaluate the performance of the proposed actuator. To evaluate the electromagnetic field of the actuator ,2D-axisymmetric FEM solver is used. Generally, COMSOL Multiphysics software is a multipurpose software, in which the magnetic field module is used for the designing and analyzing of the LOA. Starting from the designing process and setting conditions for the purposed model are elaborated. Different parameters settings, materials used, coil and different setting conditions are explained. The performance of the proposed actuator is analyzed using parametric sweep on that parameter and select the optimum value under constrained region. And similarly, the output response is examined using g parametric sweep on the input loading parameters.
After completion of COMSOL designing the process od fabrication will start. Lathe machine is used during fabrication, to manufacture all the required parts of the proposed model of LOA (for both the magnets). In the fabrication process the most important thing is that the dimensions of all required fabricated parts must be same as in COMSOL designing. The stator and mover are made of low carbon steel and wire used is made of copper of 18 gauge in AWGS. Coil is made using winding machine and to keep the dimensions of the coil accurate, Vernier caliper is used. Dimensions of the coil must be accurate to keep the coil stress-free in the housing in stator core. The tube of mover core has embedded PM on both sides.
At last, when both the simulation and fabrication completed. The final step is to analyze the experimental results for both magnets using different tests. And when all the results analyzed then the process of comparison will start, and the output results of both magnets will compare for the use of compressor applications.
Benefits of the ProjectThis project is beneficial for the refrigerator industry like Haier, Dawlance etc. but especially it would be helpful for the local industries which cannot afford the expenses of other types of expensive actuators. The structure is very simple and have less friction points. Due to the less frictional points there will be less losses. This is also environmental friendly because the noise effect is almost negligible. This is also cost effective because lesser mechanical parts are used, and the main advantage of this project is efficient use of energy. And after this project the manufacturers will be able to design the compressor with higher efficiency in low cost.
Technical Details of Final DeliverableMostly in many projects Halbach array configuration is used. The cost of ring-shaped magnets is high and in manufacturing difficulties occurred. Ring shaped permanent magnets have low mechanical strength.
To solve the above problems, the magnets used in this project are axially magnetized. The thrust force of proposed LOA is high, and LOA have low cost, easy to build and overall volume is small as compared to recently designed linear oscillating actuators. In proposed project axially magnetized ring-shaped magnets are used instead of using axially magnetized disk-shaped magnets because they have high mass of the mover.
This project has tubular topology with moving magnets mechanism. This moving magnet type actuator is having a low mover mass, its dynamic response is fast and have a value of high thrust force density and compared with other types of actuators like (moving iron or moving coil type) and it has better efficiency.
The thrust force obtained from the rare earth magnets is high as compare to ferrite magnets but on the other hand ferrite magnet is cost effective. So, for the use of compressor applications ferrite magnet is best for use because we can easily obtain the required thrust force in cheap cost by using ferrite rather than using of rare earth magnets
Final Deliverable of the Project Hardware SystemCore Industry ManufacturingOther IndustriesCore Technology Shared EconomyOther TechnologiesSustainable Development Goals Decent Work and Economic Growth, Industry, Innovation and InfrastructureRequired Resources| Item Name | Type | No. of Units | Per Unit Cost (in Rs) | Total (in Rs) |
|---|---|---|---|---|
| Total in (Rs) | 79396 | |||
| Aluminum | Equipment | 1 | 8000 | 8000 |
| Low carbon steel | Equipment | 1 | 3000 | 3000 |
| nuts and bolts | Equipment | 1 | 1500 | 1500 |
| Load cell (S shaped) | Equipment | 1 | 8000 | 8000 |
| load cell display | Equipment | 1 | 9000 | 9000 |
| variable power supply | Equipment | 1 | 19000 | 19000 |
| copper wire | Equipment | 1 | 6000 | 6000 |
| springs | Equipment | 4 | 250 | 1000 |
| work banch | Equipment | 1 | 7000 | 7000 |
| Aurdino | Equipment | 1 | 1000 | 1000 |
| Magnets | Equipment | 6 | 1066 | 6396 |
| Mechanic charges | Miscellaneous | 1 | 5500 | 5500 |
| Transport charges | Miscellaneous | 1 | 4000 | 4000 |