This seminar discusses the design and manufacturing of bearing cups. It describes the different types of presses and dies used in the process, including blanking, piercing, and drawing dies. Calculations are shown for determining the required forces for each operation. The total force required for the compound die is estimated to be 8.4 tons. The cost of manufacturing the die is estimated to be Rs. 9000. The seminar concludes that bearing cups can be efficiently manufactured in batches of 6000 using this compound die.

1. SEMINAR ON
DESIGN AND MANUFACTURING OF
BEARING CUP
y L. DINESH REDDY 07241A0304
y R. SHIVA KUMAR 07241A0319
y B. THARUN VISHNU 07241A0323

2. INTRODUCTION
y Press Tool
y Press Tool is a set of plates with a relief, or depth-based
design, in them. The metal is placed between the plates,
and the plates are pressed up against each other,
deforming the metal in the desired fashion.
y There are different types of press machines:
y Some of them are:-
y C-type( fixed type & open back inclinable press)
y Single action straight side press
yy Typical Hydraulic press

3. DIE
y A Die is an assemblage of parts used for producing
different sheet metal components.
y The Die is also called press tool as the dies are used on
different types of presses based on the cutting forces
required for the component.
y In this project a blanking die, piercing die, drawing die is
produced for production of bearing cap used to protect
from dust from bearings of a ceiling fan.

4. y There are different types of die to press relationships:-
y Press Shut height
yy Capacity of press
y Feed Height
Materials used for making die sets:-
¾ HCHC
¾ Mild steel

5. Bearing cup
y Our Project lays emphasis on the design of sheet metal
dies for production of bearing cup used to protect the
bearings by preventing the dust to enter .The main
objective of the our project is to design a bearing cup
by the following operations:-
y Blanking Operation
y Piercing Operation
y Drawing Operation

6. 3D-diagram of bearing cup

7. 3D view of bearing cup

8. Blanking operation
y Blanking: Blanking is used to produce
blanks o b a s of desired contour and size by
cutting them out of the stock strip. Blank
is the desired ‘piece part’ made by
Blanking operation.
y Remaining after blanking is called as
‘scrap’

9. Inverted top view of blanking and
piercing die plate

10. 3D diagram in catia

11. Piercing operation
y Piercing: This operation consists of
simple hole punching. It differs from
blanking in that the punching (or material
cut from stock) is the scrap and the strip
is the work piece.
yy Piercing is nearly always accompanied by
a blanking operation before, after or at
the same time.

12. Top view punch and stripper plate

13. 3D diagram in catia

14. Drawing operation
y A flat blank is formed into a cup by
forcing a punch against the center portion
of a blank that rests on the die ring.

15. Top view of drawing die

16. 3D diagram in catia

17. Die placed in open back
inclined press

18. Strip layout
y Strip layout plays an important role
especially in the case of the design of the
press tool.
yy Strip decides the economic utilization of
the work piece and helps in the decrease
of cost of the job and reduction in the
production time by increasing the number
of components.

19. Working

20. Design calculations
Blanking calculations :
y Shearing force for blanking operation:
Shear force F= (K*L*T*S)/1000 TONS
K =1.2 for normal clearance
L = perimeter of the blank = 188.4 mm
T =thickness of the stock strip = 1 mm
S =shearing strength of mild steel = 21 kg/sq.mm
Shearing force = (1.2*188.4*1*21)/1000 TONS
= 4.7 TONS

21. Piercing Calculations:
y Shearing force for piercing operation:
y Shear force F= (K*L*T*S)/1000 TONS
y K =1.2 for normal clearance
y L = perimeter of the hole = 78.5 mm
y T =thickness of the stock strip = 1 mm
y S =shearing strength of mild steel = 21 kg/sq.mm
y Shearing force = (1.2*78.5*1*21)/1000 TONS
y = 2.6 TONS

22. Drawing calculations :
y Shearing force for drawing operation:
y Shear force F= (K*L*T*S)/1000 TONS
yy K =1.2 for normal clearance
y L = perimeter of the hole = 78.5 mm
y T =thickness of the stock strip = 1 mm
y S =shearing strength of mild steel = 21 kg/sq.mm
yy Shearing force = (1.2*78.5*1*21)/1000 TONS
= 1.2 TONS

23. Total tool calculations
y Total force required for the compound
tool=
y shearing force for blanking operation +
shearing force for piercing operation +
total load required for drawing operation
=4.7+2.5+1.2=8.4tons

24. Cost analysis
y COMPUND DIE Manufacturing time in hours Manufacturing cost per hour Amount in Rs
y Conventional milling 12 100 1200
y Grinding 10 100 1000
y Jig Boring, Drilling 10 100 1000
and tapping
• CNC wire cut 5 320 1600
y Lathe turning 6 100 600
y Cylindrical Grinding 3 200 600
yy Total cost 6000

25. Other costs
y Allen screw, dowel pins, high tension
rubber ubbe material are purchased from
markets, including the raw material for
making the die and the heat treatment of
the material has been charged = Rs 3000
yy Total cost of the compound die =
6000 + 3000
=Rs.9000

26. Conclusions
1) The Bearing cup can be manufactured in 3 operations
namely blanking operation, drawing operation, piercing
operation.
2)The Compound die is used in the batch operation of
6000 units of bearing cups.
3)The unit cost of the bearing cup is Rs 3.
4) The life of the compound die can be increased by
machining the vital parts like punch and the die.
5)The impact plate which is placed between the bottom
bolster and punch holder is replaced if necessary to
improve the die life.

27. References
y Tool design by Cyril Donaldson,
Donaldson Mn.
y Fundamentals of tool design by David
Spitler,John G.Nee,David Alkire
Smith,Society of Manufacturing Engineers.
y Fundamentals of press working by David
Alkire Smith.