Pioneer of geared motor / geared pump
TSUKASA ELECTRIC CO.,LTD

Most DC motors have carbon brushes. There are two types of wear with the carbon brushes: mechanical wear by carbon brushes touching with commutators to rotate a motor, and some electrical wear by commutation spark.

If a motor is rotated with low speed, it may cause short-circuit because brush wear debris between the commutator. Be sure that this may cause motor burn or a driver burn.

PWM operation may shorten the brush life compared to the conditions under the rated voltage and stable voltage. Depending on the frequency, it may accelerate carbon brush worn significantly.

Typical frequency of PWM control for a DC brushed motor is 10-20kHz. Repeating on and off, PWM control does save the energy, but it may cause heat by resonance depending on the motor parts and range of frequency.

Be sure to review the conditions by conducting thorough evaluation tests using actual applications before proceeding to your production.

* When driven in PWM at certain frequencies, it may occur that a motor does not start due to the combination of driving frequency and internally fitted capacitive noise suppressor. In that case, please select a motor with a varistor inside. Evaluation tests are still required.

Select a gear head that is designed for continuous operation. If you use a gear head that is designed for intermittent operation for continuous operation, the sliding part, where a gear and shaft touch for example, will heat up and it may even cause burn at the worst case.

Locked Gear: The time until the burn would be different depending on the gear model and operation conditions.

Refer gear head specifications from here

In some cases that a motor-gear is mounted with the shaft up, traces of lubrication oil can contaminate the brushes and commutator. This may result in shortening brush life or causing a short-circuit because it accelerates brush worn significantly when the oil reaches commutator.


To prevent this kind of accident, we offer an oil shield option for each motor. Please refer a page for product number explanation when you select the oil prevention option.


Each of geared motor products have mounting tap holes, or through holes for some products. Do not use long screws that would touch internal components when the geared motor is installed. Please refer tho the effective depth of the tap holes on our catalog when you select screws.

Any additional modification, to an output shaft for example, may damage the geared motor. It affects the product specifications due to loosened screws or dislocation of gears by shock load and / or vibration by any modification added to the product.

Be sure that overheating of a soldering gun may melt the internal parts and damage the internal structure when you solder a wire to an input terminal of the motor.


Reference: Typically, we recommend 40W soldering iron with the iron tip controlled at 320 ± 20°C by a
temperature controller, soldering time 2-3 seconds.

 Be sure not to apply any radial load higher than the allowance to the output shaft when you use a pulley, a belt chain, a warm gear, etc. to transmit the power from the motor.

Be sure about the following points when you install a pulley, gear etc. on an output shaft:

-Do not make adhesive touch a bearing of the gearhead if you mount any parts using adhesive.Be sure that volatile adhesive may damage commutators and cause faults on the motor.

- Do not apply thrust load higher than allowance on an output shaft when you press-fit any parts on the output shaft.

If any shock such as fall is applied to the motor, it may cause damage of the parts, loosened screws, dislocation of gears etc. and it may cause a failure.

If any shock such as fall is applied to the input terminal, it may cause failures because the shock causes stress on the internal connection part which results in conduction failure.

Do not rotate our geared motor from the output shaft. It may break the gears. 

Please inquire to our sales department for life time of our products.