Abstract
The idea, conceived by the author, of ship propulsion system using electromagnetic gear which is a sturdy and reliable power transmitting device based on electromagnetic action instead of mechanical contact, such as that of reduction gears was already explained in a prior paper.
In order to turn the idea to practical use, a model having a capacity of 16, 000 ps has been jointly developed by Japan Ships' Machinery Development Association and Kawasaki Heavy Industries Co. Ltd.
Shore test of the new device were conducted, at first, in combination with two electric motors which are respectively connected with the input shaft and the output shaft, and secondarily in combination with a 14, 000 ps Kawasaki MAN V14V 52/55 type medium-speed four-cycle diesel engine. Sufficiently satisfied results which can make us believe that the device can be used practically on a ship have been obtained by these tests. Some noteworthy results of these tests are as follows:
(a) The conventional efficiency of the electromagnetic gear was 95% at the input power rating of 16, 000 ps and reached 95.5% at the input power rating of 20, 000 ps.
(b) The temperature rise of the armature winding of the stator was only 60°C by measuring with an embeded thermometer after loading the electromagnetic gear with the maximum continuous rating input power of the diesel engine.
(c) Temperature rise of damper winding was very low.
(d) The rotational direction of the outer rotor could be changed smoothly in the test.
Reference: MESJ technical paper, Dec. 1974, Fukuo Shibata: “Theory and Experiment for Ship Propulsion System Using Electromagnetic Gear”
