Cam based transmission for replacement of gear box

Cam based transmission for
replacement of gear box

1. CONTENTS
Introduction
Literature Review
Problem Statement
Objectives
Advantages
Applications
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2. INTRODUCTION
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The word ‘transmission’ means the whole of the mechanism that
transmit both motion and power from the source of energy to the application
where it is to be used . However the transmission is also being used very
commonly in literature for a mechanism which provides us with suitable
variation of engine torque at the application ; either in the amplified or reduced
form.
The basic drive for any application consists of ;
a) Source of energy .
b) Devices for transmitting power from source to operating elements
(Spindles, slides , table etc.)
Machine tools are drive by either of these drives .
a) Group drive b) Individual drive.

3. INTRODUCTION
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ALL GEARED DRIVES
All geared drives are used to remove the drawback of cone –pulley arrangement .
Different speed changing methods in this category are as follows.
Change gear system
In the selection of various change gears , mounted on two shafts, sum of no of teeth
on various gears pairs must remain constant.
•Gear ratio cannot be over 2:1 & not less than 1:4
•Change gears can be replaced only after switching off drive of the machine.
Clutch type drive
In this method when claw clutch is manually engages with freely mounted gears on
driving shafts, motion is transmitted to the driven shafts .
•Toothed clutch can only be engaged at rest or when the relative speed of rotation
does not exceed 0.7 m/ sec.
Sliding gear type drive
A double cluster gear is shifted on a splined shaft so that it engages with one of gear
on second shaft to give different speeds.
•Sliding gears may be shifted only with rotation of driving shaft is switched off.
•Maximum 2,3 or occasionally gear can be used on cluster gear.
Study of the above drives for variable speed transmission in machine tools , directs to need
for a step-less s transmission device.

4. Literature Review
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1. Norman H. Beachley [1] worked on examines and compares the five basic principles
that can be used in continuously variable transmission design (CVT). It describe
commercially available CVTs suitable for motor vehicles. Basic terms used in this report are
defined in this section. A CVT is a transmission having a speed ratio that can be varied
continuously over its allowable range. Its speed ratio may take on any value between its
operational limits, i.e., an infinite number of ratios are possible. A gearbox transmission, on
the other hand, has a discrete number of fixed speed ratios. One important disadvantage of
the ratchet type CVT is that it does not allow reverse torque. The only way to get
regenerative braking is to put two such CVTs in parallel, but reversed with respect to each
other. One would then be used for positive torque and the other for regenerative braking.
2. William T. Beale et. al [2] Have carried out work on, An automatically and smoothly
continuously variable transmission, for transmitting input mechanical energy from a crank
to the drive wheel. A ratchet have oscillatory alternating motion member and a continuous
rotary motion member, connected to the driven wheel. More particularly the invention is an
entirely mechanical transmission mechanism, which automatically and continuously varies
the transmission ratio in a stepless manner as a function input and output torque and speed
Although the transmission is particularly suitable for bicycles, it also has properties which
are advantages for other vehicles and other machines.
.

5. Literature Review
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3. Brian S. Andersen[3] The purpose of this research has been to investigate the
family of positive engagement, continuously variable transmissions, which have the
possibility for higher efficiency and torque capabilities than the friction dependent
CVTs that are currently in use. The analysis of the positive engagement CVT family
reveals that all published embodiments belonging to this family must overcome a
problem called the non-integer tooth problem. This research has described this
problem as it exists in three published embodiments. This has been done to show
several ways in which this problem can be manifest.
4. T. Yukawa’s et. al [4] Have carried out work on, this paper describes the
continuously variable transmission (CVT) generally CVTs, are classified as belt-
type or toroidal CVTs, and each CVT is basically composed of two parts such as the
V-belt and pulley. or friction wheel. In the belt-type CVT, the pulley is driven by a
belt placed between two circle boards in the pulley, while in the toroidal CVT, We
have proposed an L-CVT in which the link of the quadric crank chain, the cam
mechanism and the ratchet mechanism were mounted. Since the proposed method is
not based on friction conduction, it provides a mechanism that creates no noise and
no slip [14], is durable, and offers high transmission efficiency.

6. Problem Statement
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There are many machines and mechanical units that under varying circumstances
make it desirable to be able to drive at an barely perceptible speed , an inter
mediate speed or a high speed.
Thus a infinitely variable (or stepless speed variation in which it is possible to
get any desirable speed . Some mechanicals hydraulic and electrical devices serve
as such stepless drives .However the torque Vs speed characteristics of these drives
do not match that of stepless drives at increased driving torque at low speeds.
Hence the need of an stepless drive with the following characteristics
1.Stepless or infinitely variable speed.
2.Wide range of speed variation ie(Nmax to Nmin).
3.Shifting form one speed to another should be shockless .
4.Minimum no of controls for speed changing .
5.Ease of operation.
6.Compact construction .

7. Objectives
JSPM’S Rajarshi Shahu College of Engineering Tathawade Pune. 7
OBJECTIVES
•Design & drawing of cam transmission to deliver 1:4 reduced output in step-
less way.
•Development & manufacturing of drive
•Testing of drive to derive the performance.
•Plot Performance Characteristic Curves ;
Kinematic Synthesis of cam transmission mechanism for optimized output

8. Construction & Working
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9. JSPM’S Rajarshi Shahu College of Engineering Tathawade Pune. 9

10. Advantages & Applications
JSPM’S Rajarshi Shahu College of Engineering Tathawade Pune. 10
The Cam Based IVT has the following advantages over the conventional gear
box.
1.Stepless variation of speed :-
Any speed between Nmax to N min can be obtained . The conventional gives
fixed speed ratios\ that too in steps.
2.Wide range of speeds Ratio :-
The speed ratio can be varied one a wide range which is not possible in
conventional gearbox where it is fixed speed ratio.
3.Compact size :-
The size of the gear less variable speed reducer is very compact; which makes
it low weight and occupies less space in any drive.
4.Ease of operation :-
The changing of speeds is gradual one hence no calculations of speed ratio
required for change gearing .Merely by rotating hand wheel speed can be
changed .
5.Singular control :-
Entire range of speeds is covered by a single hand wheel control .
6.Low cost .
 
 
 
 
 

11. Applications
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APPLICATION
1.Speed drives for machine tool spindles:-
Machine tool spindles are required to be driven out various speeds depending
upon
size of work & material to be cut in such cases the gearless variable speed
reducer
can be used along with the all geared head stock to give an infinitely variable
speed
reducer can be used along with the all geared head stock to give an infinitely
variable speed conditions.
2.Feed drives for machine tool slides :-
Machine tool slides can be moved at different speeds to impart feeding motion to
the cutting tool using this drive.
3.Variable speed drive for conveyors in assembly line of automatic assembly
plants .
4.Variable speed drive in automatic transfer links & pick & place type robotic
devices .
5.Bottle filling plants .
6.Indexing mechanism in automats ; etc.
 
 
 

12. References
1.L. Mangialardi, G. Mantriota, the advantageous of using continuously variable transmission in wind power
system, Renew. Energy 2(3) (1990) 201–209 [2] Lang, K. R. (2000, May 3). Continuously Variable
Transmissions. 21W. 732.
[2] Bertini, L., Carmignani, L., & Frendo, F. (2014). Analytical model for the power losses in rubber V-belt
continuously variable transmission (CVT). Mechanism and Machine Theory, 78 , 289– 306
. [3] N. Srivastava, L. Haque, A review on belt and chain continuously variable transmissions (CVT): dynamics
and control, Mech. Mach. Theory 44(1) (2009) 19–41.
[4] A.P. Lee, J.P. Newall, Durability of a compact dual-cavity full-toroidal IVT variator SAE 01-0353, 2004
. [5] F. Verbelen, S. Derammelaere, P. Sergeant, K. Stockman, A comparison of the full and half toroidal
continuously variable transmissions in terms of dynamics of ratio variation and efficiency, Mech. Mach. Theory
121 (2009) 299–316.
[6] R.R. Rajendran, Continuously variable transmission with uniform input-to-output ratio that is none-
dependent on friction, 2018, US Patent No. US 2018/0209523A1.
[7] S. Aliukov, A. Keller, A. Alyukov, Inertia continuously variable transmissions and investigation of their
dynamics, SAE Technical Paper 2017-01-1103, https://doi .org /10 .4271 /2017 -01 - 1103, 2017. 
 

13. Thank You
JSPM’S Rajarshi Shahu College of Engineering Tathawade Pune. 13