SUMA TECHNOLOGY

A machine derives the energy or power for its working from a prime mover. The power in the form of rotary motion is transmitted from the prime mover to the machine either by connecting the prime mover shaft directly to the machine shaft by a coupling or using intermediate machine elements such as gears or pulleys and belts or sprockets and chains. in all these cases the shaft is secured firmly to the flanges or gears or pulleys or sprockets which are mounted on it to prevent the relative rotation between the two a tight fit of the shaft in the bore will be usually insufficient to secure the shaft to the machine element which is mounted on it. Types of keys: Keys are classified into two main types (1) taper keys (2) parallel or feather keys. A tapered key is of rectangular or square section with uniform width and tapering thickness. It transmits the turning moment between the shaft and the part mounted on it without any rotational and axial motion between them a parallel key i

The proper performance of machine parts and structures depends on rigidly. deflection of machine spindle or cutting tools have an adverse effect on accuracy and surface finish of the component the floors of buildings must have sufficient rigidity to carry expected loads design of machine parts and structures are based on deflection of beams the lateral displacement of abeam under the load is termed as deflection. The determination of deflection of beam is essential since it is often required that the maximum defection of the beam should not be greater than the specified value. This chapter confined to the deflection of cantilevers and simply supported beams with point loads and uniformly distributed load. Different equation of deflected beam: Consider small length of the beam dx over which the bending moment may be assumed to be constant and equal. The beam bent due to bending as and small length of the beam ‘ds’ subtend an angle dθ at the center of the curvature (o) of th

Springs are resilient members and are extensively used to absorb shocks. The common application of springs. 1.To control vibration and force due to shock or impact loads. Ex: springs of railway car and automobile. 2.To control the motion of links in mechanism. Ex: springs to maintain contact between cam and its followers. 3.To apply the force to the members. Ex: springs used in balances and dynamo meters. 4.To measure the force. Ex: springs used in clock. Spring materials: Plain carbon steel of 0.9 – 1.0 % carbon is a common material for springs. Steel with 0.85 to 0.95% carbons and 0.3 to 0.4 % manganese is used for large size springs alloy steel such as chrome-vanadium and silicon-manganese steel are used for better grade springs. These alloy possess greater toughness and higher endurance limit and are better suited for springs subjected to fluctuating loads. Chromium steel phosphorous bronze andmonel metal can also be used in special cases to increase fatigue

  When a body is in a state of stress loaded externally deformation takes place a simple tensile member tends to elongate and a compressive member shortens the ratio of change in length to the original length is called strain since strain is a ratio of two lengths it is a dimensionless quantity. Thus the tensile or compressive strain is given by Strain                   = change in length/original length e = δl/l Shear strain: Consider a block is rigidly fixed to a vertical surface and force ‘p’ acts along its top fact tangentially to the top face under the action of shear force the block. Shear strain Φ      = BB’/AB = x/y Since ‘x’ will be small therefore Φ is expressed in radians thus the measure of shear strain is the rotation of the planes perpendicular to the applied shear load. Volumetric strain: Consider each face of a cube is subjected to equal compressive force. The result of this force will be reduction in volume the ratio of change in volume to the original vol

In static and dynamic bodies are considered as rigid the bodies do not undergo any change in shape under the action of force in contrast strength of materials deals with the behavior of the bodies under the action of external loads. Moreover the deformation (bodies are no longer assumed to be rigid) under the load is the major interest and an attempt is made to find out whether or not a given member fail under the load. The basic concepts of strength of materials are discussed in this chapter. Loads: Any external forces acting on a component are called loads. The loads may be classified as given below. a)    According to the manner in which they are applied. 1)    Point or concentrated loads 2)    Distributed loads Point or concentrated load acts over a very small area which is considered as a point it is expressed in N or KN. Load distributed over an area or along a length is called distributed load a load may be uniformly or non-uniformly distributed along a length o

A bolt is fastening element comprising of the head at one end a threaded portion over a cylindrical shank at the other end. The parts to be fastened temporarily by bolts and nuts admit hexagonal head   and Square head  are very common. although the square shape provides a better spanner grip than the hexagon, but needs one fourth of a turn to bring it into the same position for inserting the spanner again whereas a hexagon need only one sixth of a turn and hence preferred. the bolts through the holes in them having suitable clearance. The projected threaded end of the bolt in turn now admits the washer and nut an internally threaded member, which after sufficient turn offers necessary clamping grip. Bolts and nuts of various shapes are used fir different purposes but the        Empirical Proportions of Hexagonal Head Bolt and Nut All Dimensions in mm