Spur Geared DC Motor 12V for Commercial Blender

Overview

A customer came to us with an extremely innovative commercial blender design. Their design utilized a unique dual-mixing technology using both an AC electric motor as well as a secondary 12 volt brushed DC gear motor.

Our customer, a leading designer of commercial kitchen appliances, had a specific client who challenged them to design a blender with quicker blending times than their existing line of commercial blenders. The end user is a retail food establishment who needs to blend specific mixtures at a quicker pace to improve customer service turnaround time.

When this customer approached us, they had already been working with another mini dc motor manufacturer, but they were unhappy with their incumbent motors’ performance and suppliers’ lack of cooperation on motor design adjustments. They were satisfied with their incumbent AC motor supplier so we weren’t involved in that portion of the design.

Challenge

Decreasing blend time is not as simple as you might think. A mixture of different ingredients can be incredibly sticky, thick, and viscous. A blender requires a significant amount of power and torque to mix, requiring a strong gear reduction motor. The blender was being designed for this specific customer but at the same time they needed to think about future product expansion. The overall design had to be robust enough to handle other types of mixtures and recipes.

Since they had already been working with another micro motor, they had fixed dimensional constraints. The overall diameter of the brushed dc motor had to be less than 40mm. The motor also had to fit in their predefined water resistant enclosure, and there was very little wiggle room. We had to adhere to very specific output shaft sizing and other structural changes to seamlessly interface with their application. The motor had to have a rated voltage of 12VDC in order to work with their electronics and motor driver, as it is being powered by a rechargeable battery pack.

As is a priority with all of our customers, the gear motor had to be reliable. You can’t set blending speed records if the blender is down for maintenance. Minimizing downtime was the whole point of this operation, so reliability had to be a core focus of the gear motor design process. Usually a brushless dc motor would offer much longer useful life but in this case, we had to utilize a brushed 12V DC Gear Motor given the allotted housing constraints and preexisting electronics.

The previous supplier was located in China and they were utilizing a rather inexpensive motor. Our customer had rather aggressive price expectations already in mind and challenged us to meet their expectation.

Solution

At first we suggested that they use one of our dc 12v gear motors with a planetary gearbox to safely reach the higher torque limits, but the gear motor was slightly too expensive for their budget. Even though the planetary gear motor offered much more torque and quieter motor operation, we pivoted towards a more cost effective solution.

We switched gears and focused on a more cost-effective spur gear motor design that would perform similarly to the planetary motor, while being a bit shorter in length. This option was a pairing of one of our standard brush dc motors to an offset shaft spur gearbox with a 70:1 reduction gear ratio.

The customer was interested in both the options for comparison sake and rigorously evaluated both the spur and planetary motor. The outcome was that both electric gear motors performed satisfactorily and the customer settled on the spur gear motor option due to the lower cost.

Now that the gear motor had been selected, we began to modify it so that it fit precisely into their assembly. We had to tailor the output shaft away from our standard output shaft type D layout. The motor shaft had to be lengthened and a custom retaining slot had to be cut into it. This slot was designed to allow the motor shaft to mate with the drive assembly gearing, guaranteeing reliability for the life of the blender assembly.

We achieved durability through careful material selection to exceed our customers’ expectations but were still conscious of costs throughout the design process. Ultimately, we were able to come in under budget. Our international supply chain and nearly 50 years of experience made it possible to run large production batches that dramatically reduce the cost-per-unit, allowing these high quality DC geared motors to be offered at an affordable price. We also helped with the international logistics and shipping to their global contract manufacturer.