Page 3.1 For any more you are on your own to copy paste a page in the translator
"NDIRECT TRANSMISSION ORGANES
Organs for indirect transmission are characterized by a change in the frequency of rotation between the leading and the led. The transmission ratio, symbol i, is equal to the ratio of the angular velocity of the leading part 1 to that of the trained part. It is also the ratio of the rotational frequencies of the leading part 1 and the led part 2: i n n ' ' ' ' ' ' ' ' ' ' ' 1 2 1 2 . In order to maintain the computational relationships with the simplest expressions, the frequency of rotation is expressed in turns per second. The angular velocity is then defined by the product of the frequency of rotation n by 2 , i.e.: 2 -n.
CHAPTER 18 GEOMETRY OF ENGRENAGES AND DENTED WHEELS
The gears are classified as indirect transmission elements because the main purpose of these mechanisms is to change the frequency of rotation between the trees leading and leading. In toothed wheeled mechanisms, the transmission ratio varies with the number of teeth of the wheels forming the gear. It is invariable on average if one neglects the geometric errors always present in a real gear. The general classification of toothed wheels and gears can be carried out according to the overall catalogue of Figure 18.1. The toothed wheels are bodies of revolution equipped with teeth transmitting movement by nesting teeth. A single gear is an elemental mechanism consisting of at least two toothed wheels. The main advantages of toothed wheel mechanisms and gears are: 1. the ability to transmit rotational movements and torque between between two trees, from the lowest to the highest. 2. to ensure a constant transmission ratio between the two trees regardless of the load applied. Exception: elliptical wheeled mechanisms whose purpose is precisely to obtain a variable transmission ratio. 3. to be able to arrange the axes of the wheels in any way in space. However, parallel-axis gear transmission is the best possible solution. 4. to obtain high safety in service and a high lifespan even in the presence of very variable efforts. 5. Relatively limited maintenance, modest footprint and an acceptable cost price, especially through the use of catalogue gearboxes. We must not lose sight of some disadvantages to be taken into account in toothed wheel transmissions. These include: 1. a sometimes annoying sound level. 2. an almost rigid transmission between the entry shaft and the exit shaft, with the damping of the bumps remaining ineffective during sudden changes in torque or speed."