Designed for motorization of a wide range of peristaltic positive-displacement pumps, the new PPGM series of gearmotors from Crouzet North America (Irvine, CA, U.S.; www.crouzet-usa.com) can be used in applications ranging from dishwashers and medical appliances to milkshake machines. The pull for product engineers? The motors’ low noise and life expectancy.

“Over the years, customers have asked for a quieter, longer-life option,” Jim McNamara, application engineer, tells APPLIANCE. “Reducing noise and increasing life were design challenges our engineers were up to. The key to reducing noise and increasing durability is reducing the number of contact points (i.e., fewer larger gears) and optimizing materials. The PPGM product line is our answer to these requests.”

To create the series, McNamara says the company started with a clean sheet of paper. “Crouzet’s approach was to combine robust motors with a robust gearbox using few gears, and a beefy metal back plate with plastic and metal gears,” he explains.

Built to withstand the highly cyclical requirements of peristaltic pumps, the motors are designed to develop significant torque at a relatively low operating rate to ensure long service life and silent operation. According to the company, the motors generate about half the noise of comparative motor models and last twice as long as similar products. “For medical applications, such as dialysis machines and other noise-sensitive applications, this gearmotor offers an important benefit not previously available,” says McNamara. “I would expect a dishwasher product engineer to find the life expectancy of our PPGM series to be very useful,” he adds.

Specific pump requirements are translated into torque, speed, and current to provide the exact motor response needed for the pump while also supplying the required flow rate and pressure for the application. “It’s my job to be sure we match the correct motor and gear ratio to the application,” McNamara says. “Pumps are rated in units of flow and pressure, which translate into power. Gearmotors are rated in units of speed and torque, which also translate into power. The key to matching the gearmotor to the pump is to use the same terms.

“In many cases, our customers are not able to tell us their requirements in terms of speeds and torques,” he continues. “Crouzet has conducted tests with various pumps, tubings, and fluids. In some cases, we can use the data from this testing to determine which motor and gear ratio would be best suited for the application.”

Engineers can customize their designs to meet specific requirements. Options include variations on shaft diameter and shape, gear material, ratio and speed value, connections, mounting options, centering pilot diameters, and number of encoder pulses. McNamara says a dishwasher engineer, for example, might even ask for an ac motor to drive the gearbox. Although he hasn’t had this request yet, he says there is a range of UL-rated reversible synchronous motors that could be adapted to drive the PPGM gearbox.

The new series is available in 16- and 30-W models and features a gearbox torque of 0.5 N•m nominal and an operating voltage of 24 V. The 16-W version is also available with an operating voltage of 12 V. A wide range of gear ratios from 12.80 to 104 can create output speeds from 46 to 455 rpm to provide the versatility necessary to meet a wide range of peristaltic pump requirements.

Encoders are available on some versions from 1 to 48 pulses for accurate flow pump rate control, and service life is rated at up to 2000 hours. The gearmotor is said to mate easily with many types and sizes of peristaltic pumps via a variety of faceplate configuration options. “We even offer an adapter plate option, which allows the users to customize their own mounting hole locations and sizes,” McNamara says. “This provides a user-friendly mechanical interface.” 

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