Magnetic device with moving iron element , Mechanical Engineering

A singly excited magnetic device with a moving iron element is illustrated in the figure below.


g = 0.10 mm

d = 2.0 cm

b = 3.0 cm

Assume the mmf in the iron and the effects of fringing and leakage flux are negligible.

a) Use the force density expression B2/2ì0 to find the force pulling the moving part to the right if B in the center leg is 1.5 T and x = 0.10 mm. Also find the coil current for this condition.

b) Find the force at x =1 mm if the current is held constant at the value in part a.

2) Two iron sheets of width D and thickness d overlap by an amount x as shown in the figure. The flux in the upper and lower sheets is and the air gap between the two sheets is y.

Find the flux  and the magnetic force(from the derivative of reluctance) in the x and y directions if:

D = 20 cm d = 1 mm y = 1 mm x = 2 cm B = 1.5 T (in iron away from gap)

Neglect fringing, leakage and the mmf in the iron.

1700_two iron sheets.png

3) Introduction to Rotating Machines

The uniform air gap rotating machine model shown in the figure at the right has a 4-pole concentrated coil winding on the stator with N total turns. When excited with a current of 5.0 A rms at 60 hz the machine has a peak air gap flux density of Bpeak =1.0 T. Assume in all cases that the iron can be considered to have infinite permeability and end effects can be neglected abd that

L = 20 cm r = 10 cm N = 50

2212_2 turns.png


a) What would be the peak air gap mmf of this machine? What is the peak value of the spatial

fundamental component of the air gap B -field?

b) What is the peak flux per pole of the machine? What should the width of the yoke 'd' so that the peak flux density in the yoke is the same as in the air gap?

c) What would be the peak torque produced if a uniform distribution of conductors with 100 total conductors (25 for each pole) and carrying the same 5.0 A rms in series with the original winding were added as shown in the figure below? What would be the average torque?

d) If the conductors of this machine are relocated to create a two pole concentrated coil machine, what value of rms current would be needed to give a peak field of 1.0 T? What would be the new 'd' to keep the yoke flux density =1.0 T?


e) Assume two more windings identical with the original 4-pole concentrated coil winding but displaced by 120 electrical degrees (60° mechanical) are added to form a three phase winding. Assuming balanced three phase sinusoidal currents of 5.0 A rms and given that the Fourier series of a rectangular wave is find


the peak amplitude and mechanical rotation speed of the fundamental rotating B-field.

Posted Date: 3/16/2013 3:34:01 AM | Location : United States

Related Discussions:- Magnetic device with moving iron element , Assignment Help, Ask Question on Magnetic device with moving iron element , Get Answer, Expert's Help, Magnetic device with moving iron element Discussions

Write discussion on Magnetic device with moving iron element
Your posts are moderated
Related Questions
Stitch Welding This is a variation of spot welding, in which a series of overlapping spot welds are made in the same manner as stitching cloth. Stitch welding may be performed

Study literature and give a discussion of the applicability of the continuum mechanics hypothesis to the nano-scale mechanics (solids and fluids). Your paper must be detailed but c

Prlblems 1 & 3 can you provide accurate and clear solved out solutions not done by computer either.

A simply supported beam of length 5m takes a uniformly increasing load of 800 N/m at one end to 1600 N/m at the other end. Draw the shear force and the Bending moment diagrams for

Q. What do you mean by Line Designation Tables? Development of the Line Designation Tables (LDT's) is carried out in conjunction with the evolution of the P&ID's. Engineering

What is tetra & octahedral voids & how are they formed ?

Q. Explain the procedure of Rockwell hardness tests? Rockwell hardness tests per ASTM of the deposited weld, and heat affected zone shall be required for procedure qualificatio

A pull up door is stuck in the closed position. A strap, fastened on the inside bottom and located at the center of the door is pulled outward at an angle of 45 deg above horizonta

Q. Heavy traffic areas in pumps? These are areas around pumps, filters, control valves, PSV's and other equipment requiring frequent maintenance or servicing. Piping attache

Q. What is Epoxy Powder? The coating manufacturer shall be consulted as to the product best suited to the Applicator's speed of coating, pipe diameter and wall thickness, and t