MLS MMLS3, Operator'S Manual

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MLS Test Systems Pty Ltd
Revised: April 2013
4
SECTION 2: FEATURES AND DESCRIPTION
The MMLS is a scaled down heavy vehicle simulator used for
accelerated trafficking of model- or full scale pavements. The four
300mm diameter single wheels can typically apply 7200 real wheel loads
per hour. Normal inflation pressure for the pneumatic tyres is 700 kPa,
with a maximum of 800 kPa. The maximum wheel load is 2700 Newton.
The machine is supplied with the wheel load set to 2700 Newton. If the
machine is transported by air, the tyres are deflated to about 200 kPa.
Please inflate to the correct pressure before testing.
The machine contains the following main components: (See fig 1).
a) The rigid frame with four adjustable legs.
b) Looped guide rails mounted on the frame.
c) Four bogie carriages, each with one 300mm diameter pneumatic
wheel and six guide wheels.
d) Four link sections, each with six guide wheels.
e) The drive drum
f) The curved wheel guide
g) The mechanism for lateral displacement
h) Detachable castors for moving the machine over short distances.
i) The control unit in a separate box.
The bogies and link sections are linked together to form an endless chain
with a total of 48 guide wheels and four pneumatic trafficking wheels.
The guide wheels move along the two sets of guide rails. When a bogie
moves along the bottom straight section of the rails, the pneumatic tyre is
in contact with the underlying pavement, applying a load to it.
The spring loaded drive drum pinches some of the guide wheels against
the outer rail. As the drum rotates the guide wheels are moved along in
much the same way as with a planet gear system, driving the chain of
bogies around. The drum is driven by a 1.5 kW variable speed electric
motor.
The trafficking wheel of each bogie has an adjustable suspension system
by which the wheel load can be set. The suspension has a displacement
travel of about 20 mm. Once set, the geometry of the suspension system