More than 40 years of operation under heavy-duty conditions: We recently received a request for a replacement motor for the drive of a milling disc – the original BEN motor dated back to 1981. Its performance was so impressive that the replacement motor was ordered with the exact same specifications as the original from 1981.
A Motor for Harsh Conditions
This is a heavy-duty motor that has to withstand particularly challenging environmental conditions. Milling produces dust and dirt that must not enter the inside of the motor. Some applications involve moisture, which also needs to be kept out. To ensure a secure seal, we used a labyrinth seal in the new motor – just like the one its predecessor had. For this, grooves are machined into two separate covers that are filled with grease. As the covers rotate, the grooves interlock like a labyrinth and the grease is continuously redistributed, making it very difficult for dirt and moisture to enter. A radial shaft seal was also installed to further reinforce the seal.
The motor is size 180 with an output of 22 kW and runs continuously at just under 1,500 rpm. Due to the weight of the milling disc – about 150 kg – a reinforced double-row angular contact bearing was once again installed, just as in the original. This not only balances the weight but also compensates for the centrifugal forces that occur during milling.
Short Delivery Time Despite Special Parts
When it comes to replacement motors, prompt delivery is crucial to keep downtime and maintenance periods as short as possible. Sometimes delays can occur if specific components are no longer available for motors that get replaced after a long operating life. Fortunately, we still had many of the special parts required for the milling disc drive in stock, which allowed us to manufacture the new motor within just a few weeks. This included the slightly longer bearing end shield that provides the necessary space for the two parts of the labyrinth seal.