Function and advantages of water cooling
- Functionality of water cooling
- High torque
- High torque PLUS high dynamics
- Impurities in the air
- High ambient temperature
- Limited footprint
- Temperature-sensitive product
- Water and oil are already in the system
- Strict requirements for hygiene
- Noise emissions must be reduced
- FAQs on water cooling:
- The motor series from Baumüller are available with water cooling:
- Do you have anymore questions?
To prevent the motor from overheating, heat must be dissipated
Functionality of water cooling
The fluid cooling of electric motors can be converted in different ways. Basically, there are always ducts in the stator of the motor through which mainly water is conducted because water has the best heat coefficient. For that reason, we refer, both as a rule and also in this text, to water-cooled electric motors. The cooling pipes can either be housed in a special cover or, as in the latest water-cooled servo motors from Baumüller, directly in the motor casing. The version with the cover cooling has the result that the motor needs more space and when realized directly in the housing the dimensions of the water-cooled motors are identical to those of the uncooled motors. In principle, the water is then simply pumped through the motor and repeatedly cooled down again by a cooling unit. Then the motor does not get too hot and can deliver optimal output. The general rule: the more current is fed to the motor, the more the motor heats up and the more the cooling has to do.
Selecting the right cooling method is not simple. Many factors go into the decision and the reason for the selection of water-cooled electric motors can be varied.
In the video you will learn what makes water-cooled servomotors special and how you can use them successfully.
10 challenges where the use of water-cooled electric motors makes sense.
Dynamics refers to the way the process requires a rapid start-stop operation with few pauses. The greater the dynamics, the more current has to be supplied, and the drive heats up faster. Water-cooled electric motors are better at dissipating this heat than air-cooled motors, and thus more dynamic processes are possible. Because of the better cooling performance, the motor output is also up to 50% higher than with uncooled motors. This means that in many cases the motors can be smaller in dimensions. Smaller motors have a lower mass inertia and thus also allow for greater dynamics. These good properties of water-cooled motors with respect to dynamics make it possible to reduce cycle times and increase the productivity of machines.
Is water cooling more expensive than air cooling? Can hydraulic oil be used as a cooling medium instead of water? You will find answers to these and other questions in our FAQ. ► FAQs on water cooling
The level of nominal and stall torques of a motor is contingent on the energy that can be supplied. The water cooling dissipates the heat in the system especially effectively so that a large quantity of energy can be supplied, thereby achieving high torque levels without overheating of the motor.
High torque PLUS high dynamics
Usually it is necessary to strike a compromise between the requirements of dynamics and those of torque. Smaller motors mean better dynamics but less torque. Larger motors deliver high torque, but allow for less dynamics. When using water cooling, both requirements can be met: small size for high dynamics plus high torque thanks to optimal cooling.
Impurities in the air
If there are air impurities at the machine location, e.g. from cotton fibers in the textile industry, these can cause fans of air-cooled motors to become dirty. Dirty fans prevent effective motor cooling. Regular cleaning is required and that incurs high service costs and downtimes. Water cooling does not require cleaning and thus incurs minimal service costs. An additional problem with textile fibers in the environment is their flammability. Cotton fibers can ignite at temperature as low as 80 °C. Since the heat is dissipated directly on the motor from the water cooling, high temperatures don't even occur in the system and the motor surface remains comparatively cooler. For that reason, there are a few advantages in using water-cooled motors in the textile industry.
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High ambient temperature
When the ambient temperature is especially high at the production location, air-cooled and uncooled electric motors can no longer achieve optimal output because the air can no longer absorb the heat sufficiently. The result is a derating. The effectiveness of the water cooling is not contingent on the ambient temperature, and there is no loss in performance.
Compared to other cooling methods, the output of the electric motors is up to 50% higher with water-cooled versions. This means that in many cases the motors can be dimensioned smaller, resulting in less of a footprint. Water-cooled electric motors can also be installed close together, as there is no risk that the motors might cause each other to overheat. Space can also be saved on the fans.
The direct cooling on the motor results in less heat intake in the machine and this means that temperature-sensitive products can also be processed.
Water and oil are already in the system
When water and oil are already in use, as e.g. in hybrid servo-hydraulic applications or perhaps in metal processing, then the high initial costs for the cooling unit also fall. The system thus becomes significantly more economical and advantages such as high output and compactness become more important.
Strict requirements for hygiene
In foodstuff production and pharmaceuticals, requirements for hygiene are particularly stringent. The fans in air cooled motors produce swirling air, which is conducive to the spread of spores and germs. This problem can be remedied with water-cooled motors.
Are you looking for a motor that also meets the highest hygiene requirements?
Noise emissions must be reduced
Without the fan motors, there is significantly less of a noise load when using water cooling.
FAQs on water cooling:
The motor series from Baumüller are available with water cooling:
||Properties||Installation sizes and water cooling|
|DS2||Three-phase synchronous motor||100-200|
|DA1||Three-phase asynchronous motor||100-280|
|DSD2||Dynamic servo motor for maximum requirements for acceleration capacity and start-stop qualities||45-132|
|DSC1||Compact servo motor with high torque density||45-100|
|DSP1||High-speed servo motor with good acceleration and overload capability and increased speed and output range||45-100|
|DST2||Multipole torque motor as direct drive with very high torque||135-560|
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