Metso MP1000, Technical Reference Manual

Page: 88 / 180

SECTION 2 - GENERAL INSTALLATION INFORMATION
2-14
MP SERIES CONE CRUSHER TECHNICAL REFERENCE MANUAL
2.8.2 Tensioning the V-belt Drive
Tensioning the drive is a term used when force is
applied to the V-belt by some method to provide the
wedging action between the V-belt and the sheave.
This wedging action provides the ability for a
V-belt to transmit power from the motor sheave to
the crusher sheave.
Proper belt tensioning is the most important factor
in the successful operation of a V-belt drive. The
best tension is the lowest tension at which the belts
will not slip under maximum peak loads. Too much
tension shortens belt life, increases bearing wear,
and can lead to bearing problems. Overtight belts
can cause early failure and should be avoided. It is
suggested to monitor the temperature of the
countershaft box after tensioning belts to avoid
possible bearing problems resulting from over
tensioning.
Various methods of tensioning V-belts have been
established. Two simplified methods will be
described in the following paragraphs; Tension-
Deflection and Percent (%) of Elongation. Either of
these two methods will provide satisfactory belt
tension. Each has certain advantages for a given
type of belt.
The Tension-Deflection method should be used on
drives with standard V-belts. The Percent
Elongation method is preferred on drives with
banded V-belts. If a tension device or spring scale is
not available the Percent Elongation method may
be used for standard V-belts.
There are different conditions that exist for the
drive that require different tensioning procedures.
These different tensioning procedures will permit a
running-in of the countershaft bushing and proper
tensioning of the V-belts. These procedures are
described in the following paragraphs.
Figure 2-8 V-belt Installation and Take-up Allowances
Callout Description Callout Description
1 Crusher Sheave 4 Shorter Distance for V-belt Installation
2 Motor Sheave
5 Longer Distance for V-belt Take-up
3 Center Distance