Design and calculation of Whitworth mechanism

Design and calculation of Whitworth mechanism

Production Machines I

Liberec, 15. 1. 2013

Petr Zelený

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism animation

2

Production Machines I – Design and calculation of Whitworth mechanism

Progress of linear motion speed of slider

3

Production Machines I – Design and calculation of Whitworth mechanism

Video demonstrations of the mechanism application

4

Production Machines I – Design and calculation of Whitworth mechanism

Video demonstrations of the mechanism application

5

Production Machines I – Design and calculation of Whitworth mechanism

Summary of findings from videos and animation

Group of mechanisms:

6

Production Machines I – Design and calculation of Whitworth mechanism

Summary of findings from videos and animation

Group of mechanisms:

• transfer rotary motion to reciprocating.

Application in the field of machine tools:

7

Production Machines I – Design and calculation of Whitworth mechanism

Summary of findings from videos and animation

Group of mechanisms:

• transfer rotary motion to reciprocating.

Application in the field of machine tools:

• for horizontal Shaping Machines.

8

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism description

9

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism description

10

crank / lever

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism description

11

slotted link crank / lever

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism description

12

slider / pull rod

slotted link crank / lever

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism description

13

slotted link crank / lever

stone / pin

slider / pull rod

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism scheme

14

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism calculation

15

Task:

Given:

• vs= 50 m/min; Fs=1000 N;

• R = 700 mm; r = 150 mm;

• e = 250 mm;

Calculate:

• revolutions n,

• torque MK,

• motor power P,

• max. reverse speed vR,

• main time tm,

• secondary time ts.

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism calculation

16

Task:

Given:

• vs= 50 m/min; Fs=1000 N;

• R = 700 mm; r = 150 mm;

• e = 250 mm;

Calculate:

• revolutions n,

• torque MK,

• motor power P,

• max. reverse speed vR,

• main time tm,

• secondary time ts.

Production Machines I – Design and calculation of Whitworth mechanism

Mechanism calculation

17

Task:

Given:

• vs= 50 m/min; Fs=1000 N;

• R = 700 mm; r = 150 mm;

• e = 250 mm;

Calculate:

• revolutions n,

• torque MK,

• motor power P,

• max. reverse speed vR,

• main time tm,

• secondary time ts.

Results:

n = 30,3 rpm ; MK= 262,5 N m; P = 832,9 W;

vR= 200 m/min; tm= 1,4 s; ts= 0,58 s

Production Machines I – Design and calculation of Whitworth mechanism

Summary

We are at the end of the exercise, do you know

following?

• Include Whitworth mechanism to group of

mechanisms!

• Give an example of using Whitworth mechanism for

machine tool!

• Draw scheme of Whitworth mechanism!

• Describe Whitworth mechanism and its parts!

• Calculate parameters of Whitworth mechanism!

18

Production Machines I – Design and calculation of Whitworth mechanism

New example (homework)

19

Given:

• P = 1 kW; n = 31 rpm; R = 800 mm; r = 170 mm; e = 300 mm;

Calculate:

• torque MK,

• force on the slider Fs,

• the slide speed in the forward direction vs ,

• max. reverse speed vR,

• main time tm,

• secondary time ts.

Results:

MK= 308 N m; Fs = 1064,4 N; vs = 56,4 m/min; vR= 203,8 m/min;

tm= 1,34 s; ts= 0,6 s