MECH Dept Engineering Topics List

Friction in Machine Elements - Theory of Machines

Subject and UNIT: Theory of Machines: Unit III: Friction in Machine Elements

A screw when developed is an inclined plane. Threads are cut on a cylindrical body of diameter 'd', as shown in Fig.6.11(a).

Friction in Machine Elements - Theory of Machines

Subject and UNIT: Theory of Machines: Unit III: Friction in Machine Elements

Fig.6.10 shows a square threaded screw A free to rotate in a fixed nut B.

Friction in Machine Elements - Theory of Machines

Subject and UNIT: Theory of Machines: Unit III: Friction in Machine Elements

The efficiency of an inclined plane is defined as the ratio between the effort without friction (P0) and the effort with friction (P).

Motion of the Body Up the Plane

Subject and UNIT: Theory of Machines: Unit III: Friction in Machine Elements

The inclined plane is very frequently used in one form or the other.

Friction in Machine Elements - Theory of Machines

Subject and UNIT: Theory of Machines: Unit III: Friction in Machine Elements

Suppose a body A of weight (W) is resting on a horizontal plane B, as shown in Fig.6.4.

Friction in Machine Elements - Theory of Machines

Subject and UNIT: Theory of Machines: Unit III: Friction in Machine Elements

Depending upon the conditions of contacting surfaces, friction can be categorised into three different types, as shown in Fig.6.1.

Introduction

Subject and UNIT: Theory of Machines: Unit III: Friction in Machine Elements

Friction is a force that opposes the motion or tendency of a movement. Friction resists the relative motion of solid surface, fluid layers or material elements moving against each other.

Gears and Gear Trains - Theory of Machines

Subject and UNIT: Theory of Machines: Unit II: Gears and Gear Trains

Problems for practice: Gears and Gear Trains - Theory of Machines

Gears and Gear Trains - Theory of Machines

Subject and UNIT: Theory of Machines: Unit II: Gears and Gear Trains

Review Questions: Gears and Gear Trains - Theory of Machines

Gears and Gear Trains - Theory of Machines

Subject and UNIT: Theory of Machines: Unit II: Gears and Gear Trains

Review and summary: Gears and Gear Trains - Theory of Machines

Gears and Gear Trains - Theory of Machines

Subject and UNIT: Theory of Machines: Unit II: Gears and Gear Trains

Assuming that all gears of the epicyclic gear train rotates at uniform speeds, their angular accelerations are zero. Therefore the inertia torques of the epicyclic gear trains are zero.

Gears and Gear Trains - Theory of Machines

Subject and UNIT: Theory of Machines: Unit II: Gears and Gear Trains

Velocity ratio for epicyclic gear trains is usually found by the following two methods: