Technical DataCaution


Precautions for installation on the output shaft

If you use adhesive, take care so that adhesive will not flow into the bearing or gearhead. Do not press fit parts to the output shaft of the gearhead. Such a practice is a cause of internal breakage of the DC gear motor. Also when using adhesive on the shaft of coreless motors (motors with encoder included), take the same precautions as for gearheads. CITIZEN MICRO CO., LTD. can do press fitting upon request, but it depends on shapes. Please contact us.

Precautions concerning rotation from the output shaft

Do not rotate the DC gear motor from the output shaft side. Such a practice is a cause of internal breakage of the gearhead such as tooth fracture. In a worse cases, the motor may generate electricity to affect electronic components in the machine adversely.

Precautions concerning locking of the output shaft

Do not lock the output shaft with the DC gear motor powered on. Such a practice is a cause of internal breakage of the gearhead such as tooth fracture. Keep in mind that depending on motor specifications, locking for a short time can cause motors to burn out.

Precautions for machining the output shaft

If the output shaft needs to be machined, take sufficient precautions since a force, shock, vibration, etc. during machining may destroy the DC gear motor or if chips from machining enter the gear motor, they will become a cause of abnormal noise.

Precautions for handling the bearings

Some models of gearheads and motors employ oil-impregnated bearings. Do not use such gearheads and motors in environment where oil inside the bearings may be sucked out. If you use a bearing as a spigot for installation, pay attention to the material of the installation side (in particular when resin is used).

Precautions concerning installation

Confirm the taps for mounting referring to the external dimension drawing and select adequate mounting screws. If mounting screws are too long or if the tightening torque is excessive, the DC gear motor mounting part or mounting screws may be deformed or destroyed to cause problems. If mounting screws are too short or the tightening torque is insufficient, the screws may become loose or fall to cause problems.

Precautions concerning installation posture

The standard installation posture we recommend is the shipping inspection posture that is horizontal. If other installation postures are employed, such problems may occur that grease will leak out of the DC gear motor or the load will change to cause changes in the characteristics of the motor installed horizontally.

Precautions concerning grease and oil

Internal grease or oil may leak out of DC gear motors in unusual environment or depending on installation posture. Adhesion of grease or oil to the machine may cause cracks or other problems depending on materials of the machine. Check the materials in advance.

Precautions concerning the motor terminals

Undue force applied to the motor terminals will cause stress inside the motor to cause failures of the internal parts. Complete soldering work in the shortest possible time. (Recommended: Temperature of tip of soldering iron 380±20°C, 2 seconds or less) If heat more than necessary is applied to the motor terminals, the parts may be melted or the internal parts may be broken. During soldering, exercise care so that solder balls or flux will not enter the motor.

Precautions concerning the connectors

Do not connect/disconnect the connectors with the DC gear motor powered on. When connecting/disconnecting the connectors, hold the connector itself to avoid applying stress to the lead wires and DC gear motor. In particular, carefully handle the lead wire outlet and connector outlet.

Precautions for handling the encoder

  • If the encoder is subjected to impact by for example dropping, its function may be damaged.
  • If a tensile force is applied to the harness, the encoder case or internal PC boards may be broken.
  • Static electricity applied to the product is a cause of destruction of internal electronic components.
  • If the magnetic encoder is placed near a magnet or used in the magnetic field, the encoder may malfunction or may be damaged.
  • If the encoder is used at an overvoltage/overcurrent, the motor and encoder internal components may be destroyed. Install such safety devices as fuses and protective circuits.
  • Where surge occurs in the power supply to use, absorb surge by for example installing a surge absorber in the power supply.

Precautions concerning PWM control

When a motor with a capacitor is PWM-controlled, overcurrent may flow depending on frequencies. When you intend to use a motor by PWM control,either use a motor without a capacitor or check the frequency characteristics.

Precautions concerning onboard evaluation

The service life, noise and vibration levels vary depending on a machine on which the motor is installed. Therefore, check them with the motor installed. For such a mechanism that a large radial/thrust load is applied to the output shaft, study how to receive such load using the actual machine. If a long part needs to be mounted on the output shaft, be sure it will not be overhung.

Precautions concerning applications

These products must not be used in arsenal and military applications.

Precautions concerning failed products

If a product failed, do not disassemble it, but return it to CITIZEN MICRO CO.,LTD. together with a description of conditions of use, date and time of occurrence of the failure and symptoms. If a product is dropped, do not use it.

Precautions concerning safety

Secure safety by for example installing fuses and protective circuits to prevent potential personal injury and fire in case the DC gear motor or machine fails.

Operating temperature range

Use the products in a temperature range of -10°C to +60°C . The values indicated in the catalog specifications are the values at room temperature(about 20°C to 25°C ). If used outside the specified range, grease in the gearhead may not lubricate properly or the motor cannot be started. For higher or lower operating temperature applications, grease or motor components may be changed. Please contact us.

Storage temperature range

The products must be stored in a temperature range of -15°C to +65°C. The values indicated in the catalog specifications are the values at room temperature (about 20°C to 25°C ). If used outside the specified range, grease in the gearhead may not lubricate properly or the motor cannot be started. For higher or lower storage temperatures, grease or motor components may be changed. Please contact us.

Relative humidity range

The products must be stored in a range of 20% to 85%RH. If products are stored in very humid environment, metallic parts may be rusted to cause problems. Exercise care when storing products in such environment.

Precautions concerning atmosphere

Do not use the products in places where substances that emit harmful gases are present. Such gases may affect the inside of the gear motor adversely. In particular, special attention must be paid to low molecular silicone compounds contained in silicone products since they may cause failure of contacts inside the motor. When using adhesive or sealing agents inside the machine, ensure that no harmful gases are produced.

Precautions concerning storage

Do not store the products in atmosphere containing harmful gases, at high or low temperature and high humidity. The products must not be stored for a long time. (The maximum storage period is two years.)

Service life

The service life of DC gear motors varies significantly depending on the loading conditions, operating modes and environmental conditions. Carefully check the life with the products actually installed on a machine. The following ways of use affect the service life adversely. For such ways of use, please contact us.

  • ・ Use under load exceeding the rated torque.
  • ・ Repetition of frequent start and stop operations.
  • ・ Momentary reversal of forward and reverse run.
  • ・ Impact load.
  • ・ Continuous run for long hours.
  • ・ Use of products exceeding excessively large overhung load or thrust load.
  • ・ Short brake, counter electromotive current, PWM control and other pulse drive.
  • ・ Use of a voltage outside the rated voltage range.
  • ・ Use of products exceeding the operating temperature range or relative humidity range and application in special environment.
  • ・ If you inform us of the operating mode and environmental conditions, CITIZEN MICRO CO.,LTD. will select the best suitable model for you.

Change of specifications

Please note that the components or specifications may be changed without notice to comply with environmental regulations or due to supply conditions.

※If you want to use it other than the above conditions, please feel free to contact our sales office.