This document discusses Bennett's construction and Klein's acceleration diagram for analyzing the velocity and acceleration of reciprocating parts in engines. It contains the following key points: 1) Bennett's construction involves drawing perpendicular lines from various positions of the crank and connecting rod to analyze velocity. 2) Klein's acceleration diagram is similar to Bennett's and involves drawing perpendicular lines to analyze acceleration. 3) Bennett's construction results in a velocity diagram, while Klein's produces an acceleration diagram, both of which are used to study reciprocating motion in engines.

1. Unit-III
Dynamic Force Analysis-III
Dr. Ambuj Saxena
Associate Professor
Department of Mechanical Engineering
G. L. Bajaj Institute of Technology and Management
Plot No. 2, Knowledge Park III,
Greater Noida, Distt. G.B.Nagar (U.P.) India -201306
Theory of Machines
(RME-602)

2. Bennett’s Construction
 OC is at right angle to the line of stroke, it
occupies the position OC1 and the crosshead P moves to
the position P1,
 Produce PC to intersect OC1 at M
Klien’s acceleration diagram
𝑣𝑐𝑜
𝑂𝐶
=
𝑣 𝑃𝑂
𝑂𝑀
=
𝑣 𝑃𝐶
𝐶𝑀
= 𝜔
Reference : R.S. Khurmi (Theory of Machines)
 The triangle OCM is known as Bennett’s velocity
diagram
Velocity and Acceleration of the Reciprocating Parts in Engines

3. Bennett’s Construction • From O, draw OL1 perpendicular to P1C1 (i.e. position of
connecting rod PC when crank is at right angle). Mark the
position of point L on the connecting rod PC such that CL =
C1L1.
• From L, draw LK perpendicular to PC and from point K draw
KQ perpendicular to the line of stroke PO. From point C,
draw CN perpendicular to the line of stroke PO. Join NQ. A
little consideration will show that NQ is perpendicular to
PC.
• The quadrilateral CQNO is known as Bennett’s acceleration
diagram. It is similar to Klien’s acceleration diagram.
Klien’s acceleration diagram Reference : R.S. Khurmi (Theory of Machines)