釣掛式電動機装荷方式における電車用片当り防止歯車

Abstract

The gears, which are used in the nose-suspended motor of a motor car, necessarily come to mesh at the end of face width on account of the mechanism of motor suspension. This mechanism is usually the cause of gear tooth failures. In order to prevent the gear tooth failures, the traction gears of motor cars of the Japanese National Railway are crowned. From the results of investigations to introduce the method of deciding the form of crowning of gear, the author found that the total length of the face width of the nose suspension type traction gears used at present does not share the load effectively. Thereupon, the author tentatively designed the gear, which has the face width reduced to 2/3 and is crowned.Further, the author designed the tentative gear which is divided into two pieces, gear rim and gear boss, which are connected by the compression type rubber unit buffer. In this gear the gear rim can displace itself in relation to gear boss and the uniform tooth bearing all over the face width can be expected.These two kinds of gears which were manufactured to prevent the gear tooth failures were set on the axles of motor car, and the running experiment to test the functions of the gears were carried out. By measuring the fillet stresses with the wire resistance strain guages, the author confirmed that the trial gears had the expected functions. The results are as follows:1. In the crowned gear with reduced face width, the load is shared over all the length of the face width effectively, and the maximum fillet stress of the gear tooth appeared at the middle of the face width and was of sufficiently safe magnitude.2. The gear having the compression type rubber unit buffer has the uniform tooth bearing all over the face width, and the function to prevent the uneven contact was confirmed.These gears fabricated for trial are being tested for practical use at present.