1. A
Seminar on
Design of Rolling-Friction Power screw
(Ballscrew)
Savitribai Phule Pune University
Department of Technology
Pune
Presented by :
Shinde S. M. (MM15M09)
Jadhav Nilesh (MM15M13)
EXPERIMENTAL STUDY ON BALL SCREWS
“International Conference on
Diagnosis and Prediction in Mechanical
Engineering Systems,
2009 by Galati, Romania (XV), ISSN 1221-4590, Issue 1 TRIBOLOGY
Guided by :
Dr. Rachaiya

2. HISTORY OF BALL SCREWS
 There have been attempts to replace sliding friction
screws with rolling friction screws since the 19 century.
 The first practical application of ball screws was by
General Motors, who used ball screws for their steering
columns. Since then the technology surrounding ball
screws has advanced rapidly.
 Then used in CNC machines, automated manufacturing,
and medical devices. With superior accuracy,
repeatability, and high efficiencies ball screws are the
best way to translate rotational motion into linear motion

3. INTRODUCTION
 The primary function is ball screw is convert rotary
motion to linear motion.
 The Surface of the screw and nut are separated by Ball.
 The screw and nut have approximately semi circular
thread profile.

4. CLASSIFICATION OF BALL SCREW CIRCULATION
A) External recirculation

5. B) Internal recirculation

6. C) End-cap recirculation

7. CLASSIFICATION OF BALL’S

8. DESIGN  Preload Calculation

9.  Variable load and constant speed

10. A) Common transmission (rotary-linear)
B) Reverse transmission (linear-rotary)

14. STIFFNESS
 An indication of the rigidity of a machine.
 Total stiffness of the machine feed system.

15. THE STIFFNESS OF BALL SCREW

16. The Stiffness Of The Nut calculated by,

17. SELECTION AND INSTALLATION

18. ADVANTEGES
 Efficiency is as high as 90%
 The operation is smooth when compared to other
type of screw
 A ball screw is virtually wear free due to the
presence of lubricating film.
 Load carrying capacity is more light weight.
DISADVANTEGES
 Costly.
 Overhauling due to low friction.
 Separate brakes are used to hold the load.
 Bucking of screw and critical speed are serious
problems.
 Require high degree of cleanliness.

19. APPLICATION
 Automobile steering gear.
 Power actuator.
 CNC machine.
 Aircraft landing gear retractor.
 Transport machinery.

20. CONCLUSION
 Based on the equilibrium of the forces and moments acting
on the ball, the sliding forces between ball and both screw
and nut in a ball - screw system was determined without an
integrating of the shear stress on contact ellipses.
 A general analytical model for friction torques and
efficiency in a ball screw system has been developed . The
analytical model includes influence of the rotational speed,
axial load, lubricant viscosity and geometry of the ball-
screw system. The developed model leads to realistic
values both for the friction torque and for the efficiency of a
ball – screw system. A relation for the global friction
coefficient has been proposed. So, it can be determined a
global friction coefficient in a ball screw - system,

21. REFRANCE
 Journal on basic of AUGUST 2014 screw drive rod
less actuators –by- Igo glikin, senior Mechanical
Engineer, tolomatic,inc -http;//goo.gl//TMEOzn
www.rockwellautomation.com/go/tolomatic.
 International Conference on Diagnosis and
Prediction in Mechanical Engineering Systems
(DIPRE’09)22 - 23 October 2009, Galati, Romania
 Ball screw broacher by industrial motion control
system www.hiwin.tw
 Ball Screws. Technical Catalogue, Korta, available
onlineat:http://www.kortasa.com/uploads/descargas/
CASTELLANOINGLES.pdf

22. Thank you!