1.
S H A F T
A L I G N M E N T

2.
Contents
Basic terms
What is shaft alignment
Why is shaft alignment so important
Types of alignment
Alignment methods
Alignment Tolerances chart
Causes of misalignment

3.
Basic terms in shaft alignment
Co-linearity
Rotational centers
Misalignment
Stationary and Movable Machines
Horizontal and vertical misalignment

4.
What is shaft alignment?
Shaft alignment is the positioning of the
rotational centers of two shafts such that
they are co-linear when the machines are
under normal operation.

5.
Why is shaft alignment so important?
When shafts are misalign, forces are
generated in the coupling. Energy will be
lost and increased loads will be placed
on any mechanical components which
provide for rotation, seals, bearing
housing, etc
snap

6.
Types of misalignment
Shaft alignment begin by defining two
types of misalignment:
1.Offset misalignment
2.Angular misalignment

7.
Alignment methods
 There are a wide variety of methods for
measuring alignment, the most common ones
are:
1.Mechanical method
2.Dial indicator method
a) Rim-Face method
b) Reverse Rim method
3.Laser method

8.
Alignment Tolerances chart
RPM Excellent Acceptable Excellent Acceptable
3600 0.3 0.5 1 2
1800 0.5 0.7 2 4
1200 0.7 1 3 6
900 1 1.5 4 8
Angular misalinment Mils/inch
0.001/1
Offsetmisalignment
Mils 0.001

9.
Causes of misalignment
Increased vibration
Increased energy loss
Increased load on bearings, seals and
other mechanical components
Reduced production capacity
Reduced product quality

10.
Vibration
Misalignment causes vibrations. Vibrations
are measured horizontally, vertically and
axially and there are some rules of thumb in
the analysis of the vibrations.
Horizontal vibrations indicate imbalance (H).
Vertical vibrations indicate a weak or loose
foundation (V).
Axial vibrations indicate misalignment (A)

11.
Vibration

12.
Alignment methods
Straight Edge
Reverse Rim
Rim-Face
Laser

13.
Co-linearity
 Two shafts are said to be co-linear when
their respective rotational centers form a
single line.

14.
Rotational centers
 All shafts, whether they are straight or bent,
rotate on an axis called the rotational center.
The rotational center forms a straight line.

15.
Misalignment
 Shafts are misaligned when their rotational
centerlines are not co-linear, when the
machines are operating.

16.
Stationary and Movable Machines
 When aligning any two machines, one is
designated as stationary and one as movable.

17.
Horizontal and vertical misalignment
Horizontal Misalignment
Misalignment conditions viewed from the top and
corrected by sliding the front and back of the machine
from side to side are termed horizontal misalignment.
Vertical Misalignment
Misalignment conditions viewed from the side
(elevation) and corrected by making shim changes at
the front and back of the machine are termed vertical
misalignment.

18.
Horizontal Misalignment

19.
Vertical Misalignment

20.
1.Offset misalignment
 In shaft alignment, offset misalignment pertains
to the deviation of one shaft centerline from
another shaft centerline at a given point (or
plane) along the length.

21.
2.Angular misalignment
 Angular misalignment is most easily defined
as the slope relationship between two
rotational centers.

22.
1.Mechanical Method
Straight edge/feeler gauge method:
 Offset misalignment is measured using a
straight edge and set of feeler gauges.
 Angular misalignment is measured by using
feeler gauges, taper gauges.
snap

23.
Straight edges
Offset
Angular

24.
2. Dial Indicator Methods
Rim-Face Method:
This was the standard method of alignment.
When using a rim-face method, one
measurement is taken on the rim of the
coupling to determine shaft offset. Another
measurement is taken on the face of the
coupling to determine shaft angularity.

25.
Rim-Face Method:

26.
Why is shaft alignment so important?
Forces generates
on coupling
Damaged seal

27.
T H A N K
Y O U
GHULAM MOHIUDDIN