How do you design the diameter of a shaft?

Design Procedure

  1. Draw the bending moment diagram to find out the maximum bending moment (M) on the shaft.
  2. Calculate the area moment of inertia (I) for the shaft.
  3. Replace the maximum bending stress (Tb) with the given allowable stress for the shaft material.
  4. Calculate the radius of the shaft.

What is the diameter of a shaft?

The shaft diameter is defined as the diameter of the hole in the iron laminations that contains the shaft, as indicated with the red arrow in Fig. 1 (and not as the actual diameter of the mechanical shaft, which can be much smaller).

What are the design considerations for shaft?

Shaft design considerations include:

  • Size and spacing of components (as on a general assembly drawing), tolerances,
  • Material selection, material treatments,
  • Deflection and rigidity, a. Bending deflection, b. Torsional deflection, c.
  • Stress and strength, a. Static strength, b. Fatigue, c.
  • Frequency response,

What is machine design shaft?

A shaft is a rotating machine element, usually circular in cross section, which is used to transmit power from one part to another, or from a machine which produces power to a machine which absorbs power.

How is shaft thickness calculated?

P = 2πNT /60 . You can find out the Torque (T). t ( shear stress) . by this equation you can find out the Diameter of the shaft (D).

Why are shafts made with different diameters along the length?

Shafts are generally designed as steeped cylindrical bars therefore they have different diameters throughout the length, although the shafts having constant diameter are easy to produce. The magnitude of the stress in stepped shafts varies with their length.

What is ASME Code for shaft design?

ASME Code states that for shaft made of a specified ASTM steel: Ss(allowable) = 30% of Sy but not over 18% of Sult for shafts without keyways. These values are to be reduced by 25% if the shafts have keyways.

What’s the formula for the diameter of a circle?

2 x radiusCircle / Diameter

Is diameter a length or width?

Diameter is the length of a line touching two points on a circle that passes through the center. Diameter exists only for circular, or for circle-based objects like a sphere or cylinder, thus the width and length should always be the same.

Does torque increase with diameter?

It is more useful to say that torque is proportional to the ratio of the radii of a pair of pulleys or gears. Also RPM is reduced or increased in the same ratio so a small diameter gear driving a larger one increases torque but reduces RPM at the output shaft.

What is a key in machine design?

key, in machine construction, a device used to prevent rotation of a machine component, such as a gear or a pulley, relative to the shaft on which it is mounted. A common type of key is a square bar that fits half in a groove (keyway) in the shaft and half in an adjoining keyway in the component.

How do you determine diameter?

The formula to find the diameter states the relationship between the diameter and the radius. The diameter is made up of two segments that are each a radius. Therefore, the formula is: Diameter = 2 * the measurement of the radius. You can abbreviate this formula as d=2r.

What is a diameter example?

Diameter is defined as the length of a straight line through the center of a circle. An example of a diameter is the length of a line sliced down the center of a pie.

Which instrument is used to measure the diameter of shaft?

Outside micrometers are used to measure diameter and thickness of shafts, wires, plates.

Does shaft diameter affect RPM?

Also RPM is reduced or increased in the same ratio so a small diameter gear driving a larger one increases torque but reduces RPM at the output shaft.

How do you calculate torque from diameter?

Find Torque, the use following to find dia. Torque = pi/16 * Shear Strength * cube of shaft diameter. This is a simplified calculate so if you want to do more calculate refer any machine design book (ex: design of machine elements but rs khurmi) and there you will get more detailed calculation.

What is ASME code for shaft design?

What is shaft in machine design?

/ ►Courses / ►Courses Under Refinement (Version 2.0) / ►UG Courses – Agricultural Engineering (Version 2.0) / ►Machine Design / ►MODULE 4. / ►LESSON 14 DESIGN OF SHAFTS LESSON 14 DESIGN OF SHAFTS 14.1 Introduction Shaft is a common machine element which is used to transmit rotary motion or torque.

How to calculate the diameter of the shaft?

L          = Length of the shaft J           = Polar moment of inertia of the shaft about the axis of rotation G         = Modulus of rigidity of the shaft material Therefore for the known values of T, L and G and allowable value of angle of twist, diameter of the shaft can be calculated.

What are the cases for designing shafts on the basis of strength?

In designing shafts on the basis of strength, the following cases may be considered: (a) Shafts subjected to torque (b) Shafts subjected to bending moment

How do you design a shaft for an electric motor?

Shaft design includes the determination of shaft diameter having the strength and rigidity to transmit motor or engine power under various operating conditions. Shafts are usually round and may be solid or hollow. Shaft torsional shear stress: Ss = T*R / J. Polar moment of area: J = π*D4 / 32 for solid shafts.