Two miniature gear motor introductions

A variety of electric motors continually makes its way to the market.

By Control Engineering Staff August 26, 2004
Sanyo 12GN Series gear motors exhibit less than 40 m/s2vibration and quiet operation (under 55 dB at 5.0 V), due to the close tolerance precision of rotating parts. Operating temperature range is 0 to 50 °C, with reduced life expectancy in colder environments.

A variety of electric motors continually makes its way to the market. Recently, two new miniature gear motors are in the news: Sanyo DC Micro Motor Division’s high torque, 12-mm 12GN Series dc micro motors, intended for robotics and mini appliances; and Nidec Copal USA Corp .’s LB16-120-BB miniature brushless dc line. See and read about these gear motors in the following summaries and get more information from the manufacturers’ Web sites.

Sanyo 12GN Series geared dc micro motors—measuring only 12 x 10 x 29 mm (from terminals to tip of shaft) and weighing 8.7 g (0.31 oz)—reportedly offer designers a space saving alternative to much larger dc motors. Starting torque is 300 mNm (42.5 oz-in.) and rated load is 20 mNm.

The 12GN Series comes with a choice of four gear ratios: 75.7:1 (Model NA1S); 134.5:1 (Model NA2S); 196.6:1 (Model NA3S); and 297:1 (Model NA4S). Motors with limiters are also available. No-load speed has a range of 62 to 246 rpm, depending on model, while no-load current is 120 mA.
Other applications for these small motors include power tools, medical and dispensing equipment, and mini printers. Introduction of smaller, 8- and 10-mm diameter gear motors is expected in late 2004.

Nidec Copal’s LB16-120-BB miniature gear motor has low audible noise signature of 45 dbA when measured at a distance of 1 ft from the unit.

Pricing of 12GN gear motors is under $3.00 in volumes of 100K or more, depending on model and features.
New Nidec Copal LB16-120-BB brushless dc gear motors come with integral speed control and include a current limiting circuit as protection against excessive input currents. The miniature motors have dimensions of 0.63-in. OD x 1.31-in. long, and weigh under 1 ounce. Input voltage ranges from 3.5 to 13.2 V dc for operation under variable-speed control.
LB16-120-BB motors use a 120:1 spur geartrain to provide 3.5 oz-in. rated torque at 100-rpm speed. These 12 V dc gear motors achieve a continuous load range of 0 to 6.9 oz-in. For load starting and acceleration, a peak torque of 50 oz-in. (354 mNm) at 0.8 Amp is available.

—Frank J. Bartos, executive editor, Control Engineering,