Kinematic analysis of synchromesh, machine tool gear box, differential gear box self study 3. This type of transmission are used by skoda,toyota, lexus, etc epicyclic gearing planetry gearing. So, this is the most common gear and lot of inter changeability concept can be followed in these gears. Epicyclic gear trains are generally used for automatic transmission, overdrives, and final drives.
A gear whose axis itself is revolving is called a planetary gear. Introduction to gear trainsintroduction to gear trains. For example, commonly used epicyclic gear train, for the same purpose that it can create two output speeds from one input speed is in automobile differential. Epicyclic gear train nptel pdf automatic transmission has not better fuel economy. Nptel nptel online certification course course on spur. When pinion is the driver, it results in step down drive in which nptl output speed. Helical gearing, in which the teeth are cut at an angle with the axis of rotation, was developed after spur gearing and has the advantages that has the smoother action and tends to be trainw fig. Epicyclic gear train nptel pdf in the first three types of gear trains, the axes of the shafts over which the gears are mounted are. Types of gear train and velocity ratio calculation techminy.
The optimization is based on a multicriterion technique consisting of a minmax method combined with a direct search. Most gears are in the hardness range of approximately rc 30 to rc 38 or rc 55 to rc it is interesting to note that oil sample collected after 3 hours of operating gear at rpm no load conition show wear fig. Working principle and kinematic relations will come next, then components of harmonic drive, then gearing and transmission ratio. In this lecture, i shall give a brief history of toothed gear invention and development and next something about the gear train, then special sophisticated gearing. In some epicyclic gear trains, we may find two or more planetary gears. Gear train it is defined as two or more gears are made to mesh with each epicyclic gear train the axes of the shafts over which the geaar are mounted, may move relative to a fixed axis. In this lecture i shall cover gear unit design 1st stage pinion and gear design, probable dynamic load and wear load capacity, and then i will finalize the 1st. What are the sources of errors in gears and measurement of spur gear. Procedure for optimum design of a twostage spur gear system. In this paper, an optimum design of a twostage spur gear system is performed. The gear wheel transmitted motion between one shaft to another shaft, so the multiple set of gear transmit motion from single main gear to various revolving parts is known as gear train.
Types of gear train and velocity ratio calculation. Another class of gear train has wide application, the epicyclic or planetary train. Asok kumar mallik department of mechanical engineering iit kanpur. The primary purpose of gears is to transmit motion and at the same time, multiply either torque or speed, torque is a function of the horsepower and speed of the power source. It require small area during the power transmission and to obtain large speed reduction. It is an indication of the power transmitted through a driving shaft and from it the gear tooth loads are ealculated. In this planetary gears sets are placed in series to provide transmission.