rulmeca 80LS Manual De Instalación Y Mantenimiento página 10

EN
Example: A conveyor is running in a facility with an ambient temperature of 45°C. The temperature of the motor
cannot be dissipated as it should be. The motor temperature will increase to a dangerous level.
Example: a conveyor belt in an application with an ambient temperature of +24
temperature of +70 C, will have a motorized pulley "ambient temperature" that is significantly higher than +40
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this case, the temperature of the material is higher than the max. Allowed ambient temperature which is necessary
for a proper heat dissipation. A situation is then created due to heat accumulation (heat storage) between the
the belt and the motorized pulley body.
bottom of
For ambient operating conditions lower or higher than allowable ambient temperature (-25°C to 40°C),
contact RULMECA.
In many cases it is possible to use specially designed motorized pulleys to perform tasks for special
applications – e.g. modular plastic belts and v-belts for motorized pulley types 80LS to 165E/LS. Please
contact RULMECA for such applications.
Operating Rulmeca motorized pulleys to drive standard conveyor belts outside of the allowable ambient
temperature range voids product warranty.
n) Surface Coating:
The motorized pulley types 400L to 1000H/HD are supplied with a salt water resistant primary paint coat of 140
microns. For aggressive environmental conditions the motorized pulley should be painted to a thickness of 280µm.
In this case it is essential to ensure that no paint material enters the gap between the shaft and the end housing to
prevent possible damage to the shaft sealing. Motorized Pulley types 220M to 320H are supplied with high resistant
powder coated end housings. The shells and shafts are treated with anti-rust wax.
o) Belt Pull:
The catalogue specifies "Actual Belt Pull" for each model, power, and speed of pulley. Note that the specified actual
belt pull allows for motor and gearbox efficiency losses (95 – 97%).
Always select the motorized pulley power by comparing calculated "required belt pull (F)" with "Actual Belt Pull" and
not simply on the basis of calculated Power (kW).
Belt pull "F" is a summary of all of the existing forces to convey the material. E.g.
1. F1 – force to move the belt,
2. F2 – force to accelerate the material,
3. F3- force to lift or lower the conveyed material,
4. F4 – force to clean the belt,
5. F5 – force to overcome the skirt board friction or roller resistance,
6. F6 – force to frictional resistance of ploughs, etc.
Furthermore, with special application additional power requirements can be needed (e.g. for belt operating under a hopper, squeezing
of belt, belt guiding, extreme stiff belts etc.).
p) Mechanical Backstops:
Motorized pulleys fitted with mechanical backstops must be used on inclined conveyors to prevent run
back of the loaded belt which may result in minor or moderate injury when power supply is off.
The backstop is built into the motorized pulley and is mounted on the rotor shaft.
If pulley is supplied with optional mechanical backstop, direction of proper rotation of pulley is indicated by an
aluminium arrow or plastic sticker fastened to the end housing on the terminal box (or power cord) side of the pulley.
Clockwise or counter clockwise backstops are available.
Rotation direction is to be specified when placing order.
Pulley rotation is specified from the point of view of a person looking at the pulley from the terminal box (or power
cord) side of the pulley.
It is essential that the identity of each of the three phases of the power supply be determined before attaching power
supply wires to the pulley to prevent motor from driving against the backstop. The identity of each of the three
phases of the motor is clearly labelled on the terminal board, terminal strip, or wires (in power cord type).
Driving the motor against the mechanical backstop may damage motor
and/or backstop and voids product warranty.
C, carrying processed material at a
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Friction
between belt
and Material
– 8 –
C. In
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weight (t/h)
Belt Pull = F (N)
F = F1 + F2 + F3 +.....