Question

Write a short report (not exceeding 2 pages excluding the reference list based on APA Style (Double spacing)) about shafts. You need to explain their applications and also the fabrication process in your own words (Minimum 3 references). The report includes introduction, main body, conclusion and reference list. (PLEASE WRITE IN THE COMPUTER NOT IN A HAND WRITTEN PAPER THANKS!)

Answer 1

SHAFTS

Introduction:-

​​​​​​shaft may be a rotating machine element, usually circular in cross section, which is employed to transmit power from one part to a different , or from a machine which produces power to a machine which absorbs power.

Shaft may be a common and important machine element. it's a rotating member, in general,has a circular cross-section and is employed to transmit power.

The shaft could also be hollow or solid. The shaft is supported on bearings and it rotates a group of gears or pulleys for the aim of power transmission. The shaft is usually acted upon by bending moment, torsion and axial force. Design of shaft primarily involves in
determining stresses at juncture within the shaft that's arising thanks to aforementioned loading. Other two similar sorts of a shaft are axle and spindle. Axle may be a non-rotating member used for supporting rotating wheels etc. and do not transmit any torque. Spindle is just defined as a brief shaft. However, design method remains an equivalent for axle and spindle as that for a shaft.

Types of shafts:-

They are mainly classified into two types.

Transmission shafts are wont to transmit power between the source and therefore the machine absorbing power; e.g. counter shafts and line shafts.
Machine shafts are the integral a part of the machine itself; e.g. crankshaft.

Material for shaft:-
The ferrous, non-ferrous materials and non metals are used as shaft material
depending on the appliance . a number of the common ferrous materials used for
shaft are discussed below.

Hot-rolled plain steel :-
These materials are least expensive. Since it's hot rolled, scaling is usually
present on the surface and machining is required to form the surface smooth.

Cold-drawn plain carbon/alloy composition :-
Hence it's cold drawn then got its inherent characteristics of smooth bright finish. Amount of machining therefore is minimal. Better yield strength is additionally obtained. This is widely used for general purpose rotating shaft .

Alloy steels :-
Alloy steel together can understand may be a mixture of varied elements with the parent steel to enhance certain physical properties. To retain the entire advantage of alloying materials one requires heat treatment of the machine components after it's been manufactured. Nickel, chromium and vanadium are a number of the common alloying materials. However, steel is dear .

These materials are used for relatively severe service conditions. When the situation demands great strength then alloy steels are used. they need fewer tendencies to crack, warp or distort in heat treatment. Residual stresses also are less compared to CS(Carbon Steel). In certain cases the shaft must be wear resistant, then more attention has to be paid to form the surface of the shaft to be wear resistant.

The common types of surface hardening methods are,
Hardening of surface

Case hardening and carburizing
Cyaniding and nitriding

Sizes:-

Standard sizes

Machine shafts
Up to 25 mm steps of 0.5 mm

Transmission shafts
25 mm - 60 mm with 5 mm steps
60 mm -110 mm with 10 mm steps
110 mm -140 mm with 15 mm steps
140 mm - 500 mm with 20 mm steps
The standard lengths of the shafts are 5 m, 6 m and seven m.

Application of shafts:-

Rotationally symmetrical parts are utilized in the development of automobiles (especially in engines and transmissions), within the watch- and clockmaking industry, and in other branches of industry. Where relatively simply structured components manufactured by turning or grinding operations were formerly used, today increasingly complex contours are produced through a mixture of producing processes. High requirements for quality standards necessitate in-process internal control .

One typical example of this is often the assembly control of camshafts and crankshafts for automobile engines where a spread of various measuring tasks are combined. so as to perform an entire measurement during a single clamping action, a multisensor coordinate measuring machine is required. thanks to the close run-out tolerances of the seats of the rolling bearings, maximum precision is important . All diameters, undercuts, grooves and run-out tolerances are often measured without contacting the workpiece using the image processing sensor. A measuring probing system or laser distance sensor is suitable for measuring the shape , and measurements of axial run-out are often performed with tactile probes. This also applies to the measurement of cooling bores within the shaft.

The manufacture of various shafts within the same assembly line requires a particularly flexible measuring machine. Modules for measuring recurrent geometric features like the cam contour, the bearing concentricity, the width of land, etc. are combined to make one parameter program. The user can thus line up the individual modules of the measurement decide to match the planning of the shaft and enter the corresponding parameters. Time-consuming, detailed programming of huge numbers of individual features can thus be omitted. The results are displayed both graphically and numerically during a form suitable to the user’s needs.

It is advisable to clamp larger shafts during a vertical position for measurement (Fig. 63) so as to stop deflection of the shaft and any resulting additional errors in measurement. this is applicable especially to the measurement of extremely complex crankshafts.

Precision shafts just like the ones utilized in clocks and watches are measured along side their corresponding gearwheels and threads. Parametric programs also are used for this purpose. The high precision of the machines wont to perform measurements like these enables the inspection of diameter tolerances of only several micrometers.

Fabrication process:-

The most common process wont to manufacture shafts is via CNC turning. Using this system , workers or automated processes affix or clamp bars of materials to chucks and rotate them. While rotating, specialized tools use cutting and other subtractive processes to make and shape the top product.

The endworking process is usually utilized in high-volume production of shafts where concentricity and productivity are of particular importance. Other terms commonly wont to describe the endworking process include endfinishing, endfacing, face and center, and endfacing and turning. the method is typically performed by a CNC double-end machine using rotating tools for work on both ends of a stationary part that's gripped in an automatic fixture. The rotating tools face one another on an equivalent centerline to supply good concentricity, roundness and squareness between machine surfaces on both ends. Production steel or forged iron part shapes, like axle shafts, motor shafts, camshafts, transmission shafts and axle tubes, are frequently run on these machines.

Endworking is usually unsuitable because the first or second operation of a series of machining processes because it prepares parts for subsequent production machining operations. Some parts, require only the turning, facing, centering and threading that these machines provide. endworking can eliminate some secondary machining operations by combining them with initial end finishing, thereby increasing productivity and helping to decrease the part process scrap rate.

Major benefits of the endworking process are the value savings from working both ends at an equivalent time and therefore the improved concentricity, roundness and squareness of the machined surfaces. With parts that need stock to be turned off of the OD during a future operation, the more accurate centers leave more uniform stock removal with less cutting pressure variation during turning. variety of applications may benefit from an endworking operation to enhance the method and lower overall manufacturing costs.

Conclusion:-

Here we conclude about the shaft and it's types, sizes, applications and fabrication process.

References:-

• https://werthinc.com/main-applications-shafts/#:~:text=Werth%20Knowing-,Main%20Applications%20%E2%80%93%20Shafts,in%20other%20branches%20of%20industry.&text=This%20also%20applies%20to%20the%20measurement%20of%20cooling%20bores%20in%20the%20shaft.
• https://www.productionmachining.com/articles/endworking-enhances-shaft-manufacturing-process
• https://en.m.wikipedia.org/wiki/Shaft_(mechanical_engineering)