Skip navigation
Electronic Design

Integration Shrinks Geared Motor Size

The TPM, a highly integrated geared motor (rotary actuator), is based on an ac servo motor and high-precision planetary gearing. This compact unit is less than half the size of a conventional motor and gear combination.

Developed by Alpha Gear Drives, the TPM rotary actuator has an extremely high dynamic response. With an overall length of 186 mm, the TPM 50 builds up a maximum output torque of 500 nm at a mass moment of inertia of 2.9 kgcm2. The company claims that the dynamic response is due to the considerable reduction in the mass moment of inertia of the actuator, which has been reduced by 50% compared with a conventional solution with separate motor and gear unit.

Alpha Gear Drives designed the TPM so the low-speed motor decreases the rotor inertia. In addition, the mass inertia on the gear side is reduced by around 90% because the gear pinion is directly integrated into the motor shaft, eliminating the need for a clutch. With a load inertia of 150 kgcm2 at the output, loads can be moved through 180° with precision in less than 150 ms.

Alpha Gear Drives Inc.

See Associated Figure

Groschopp Inc. now has manufacturing compliance with the European Restrictions on Hazardous Substances (RoHS) directive. The company will replace its Sn50 Pb50 solder for Sn96.4Ag3.0Cu0.5 lead-free solder. The solder processes, including the flux and cleaner used, will remain the same. Groschopp ran tests and determined that the lead-free solder is superior because of its higher melting point than standard solder. Find out more at

Maxon Precision Motors' EC-16 sterilizible brushless motors deliver the performance and lifetime of a brushless motor in a sterilizible package. Good heat dissipation and high overload capability result from assembling the motor with the coils outside the rotor. Steam sterilization is specified at 134°C (273°F) at up to 2.3 bar for 20 minutes. The motor can be sterilized at least 100 times in an autoclave. The motor is 16 mm in diameter and 56 mm long. Continuous output power is 40 W, while maximum speed is 50,000 rpm. Maximum continuous torque is up to 12.6 mNm, depending on the winding. This sterilizible motor suits surgical, dental, and dermatological tools, as well as other biomedical devices. Go to for more info.

Lin Engineering has introduced a bipolar, 1.8°, NEMA 17 step motor combined with a microstepping driver and intelligent controller all in one compact unit. The SilverPak 17T eliminates the need for external equipment and exhibits smooth motion capabilities. It also is offered in RoHS-compliant versions. It's available in body lengths of 2.76, 2.99, and 3.31 in. and can produce up to 85 oz-in. of holding torque depending on the stack size of the motor. Custom windings are available at no extra cost. The SilverPak 17T features output currents of 0.1 to 1.5 A peak, input voltage of 7 to 28 V dc, and 16 kbytes of on-board memory. Get additional details at

See Associated Table

TAGS: Components
Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.