There are different types of magnetic motors that have been invented and some inventors have been awarded patents and some inventors have not. This overview will briefly cover three different motors that were created by three inventors; Michael Brady, Howard Johnson and Edwin Gray.
Permanent magnets are ideally designed to produce an overall magnetic field that will last forever, however some applications can expose the permanent magnet to conditions that considerably shorten their lifetime. Care needs to be exercised to ensure the permanent magnets retain their strength and exposing the magnet to things such as heat, mechanical shock and excessive repelling magnetic fields will cause the magnetic field strength to deteriorate.
There are ways to counter the conditions which are destructive to permanent magnets. The problem of excessive heat can be addresses by cooling the magnet using heat sinking techniques such as aluminium housing for the rotor and stator magnets, or liquid cooling. The main aim is to rapidly transfer the heat from the magnet into a suitable radiator. Excessive shock is easily countered by careful handling and not allowing the magnet to impact with other surfaces such as the floor, metals that are attracted and other magnets. Magnet keepers also help preserve magnets by keeping the magnet’s fields mostly within the enclosure, which is necessary for storage and transport of magnetic materials.
Edwin Gray created a magnetic motor that uses electromagnets to create a precise magnetic field burst that attracts soft magnetic or permanent magnetic materials. Soft magnetic materials can be made from a variety of elements blended together to form alloy metals or powdered materials. Generally, iron alloy materials are good for attraction because they inherently provide a very high magnetic permeability that strongly interact with magnetic fields. Permanent magnetic materials with high magnetic field strength are generally a combination of rare earth elements, diamagnetic elements, paramagnetic elements and ferromagnetic elements. An efficient electromagnet motor can use electromagnets attached to the stator and soft or hard magnetic materials attached to the rotor. Edwin Gray was awarded patents for his intellectual contribution to the electromagnet motor.
When considering the long term performance of these three different motors, Howard Johnson’s motor and Edwin Gray’s motor outperform the Perendev motor built by Mike Brady. It is important to note that Howard Johnson and Edwin Gray patented their magnetic motors in the 1970′s and were likely to have been invented quite few years before the patent office received the patent applications. It is also interesting to note that Michael Brady built his motor around 20 years after Howard Johnson’s patents were awarded.