Why do we say the gearbox runs cooler?

Why do we say the gearbox runs cooler?

If the gearbox runs a long time producing so much heat, the temperature is higher than common, not only gearbox, but also machine may be fault, and cannot operate. So the gearbox runs cooler.

  • Features
  • Quick Inquiry

If the gearbox runs a long time producing so much heat, the temperature is higher than common, not only gearbox, but also machine may be fault, and cannot operate. So the gearbox runs cooler.

The concrete mixers gearbox runs cooler having some advantages
It's a fact that the gearbox runs cooler than several others, and as a result does not require an oil cooling unit. This reduces its complexity and increases reliability while reducing its price.
We say that this is due to its 2-stage design, but this is a simplification. In fact, it is due to the higher efficiency of this particular gearbox, which in turn is mainly due to the 2-stage design.

Why do we say the gearbox runs cooler?
The speed of the motor, 1750 rpm, must be reduced to allow the mixer shaft to turn at 24 to 27 rpm. This is done with a 2:1 belt reducer followed by a 36:1 gear reducer. Every pair of gears creates a little friction which results in power loss.
If everything else is equal, each set of gears will add to the total power loss, so the higher the number of stages, the higher the power loss. Take model RG4500, which uses two 75 HP motors. Each motor consumes 55 KW (55,000 watts) when running at full load.
If each stage of the gear reducer looses just 0.5% of the power in friction, a 2-stage reducer will dissipate 1% of 55,000 or 550 watts in heat. A 3-stage reducer will dissipate 50% more, or 820 watts - almost equivalent to the electric heater you might have for warming a cold room! Luckily the mixer is not fully loaded 100% of the time, so the power dissipated will only be at this level for short periods of time.
The average power dissipation raises the temperature of the gearbox, gears and oil to a proportional amount above ambient; thus if the 2-stage example gives a temperature rise of, say 60 deg. C above an ambient of 20 deg. C, its temperature will stabilize at 80 deg. C. The 3-stage example will give a rise of 90 deg. C and its temperature will stabilize at 110 deg. C. If the oil starts to disintegrate at 100 deg. C, damage will eventually occur unless extra cooling is used.

RG twin shaft mixer gearbox runs cooler advantages
This example is a simplification and we have neglected some smaller effects such as the different ratio of the reducers in the example, which tends to level the difference somewhat. Nevertheless, the RG's 5-year gearbox guarantee shows that we are very confident in its ability to perform without an oil cooler, even when running non-stop and fully utilized for many hours each day.

This is so why do we say the gearbox runs cooler? Different cement mixers can be different type drawing. We can produce all types of concrete mixer and concrete batching plants.

Need more information?

Send us a message and a qualified representative will get back to you shortly.