Because every application involves an exceptionally large number of parameters, it is nearly impossible to exactly specify the service life of a certain motor, gearhead or motor-gearhead combination.
Service life of DC motors
The service life of a DC-motor depends largely on the selected operating point and the ambient conditions in the application. The total service life can vary greatly – from several hundred hours under extreme conditions to over 25,000 hours under optimum conditions. Under typical load conditions, the total service life of a FAULHABER DC-motor ranges from 1000 to 5000 hours.
In general, the service life of a FAULHABER DC-motor is determined by the effects of electrical and mechanical wear of the commutator and brushes. Electrical wear (sparking) depends greatly on the electrical load and motor speed. Normally, the typical service life of a motor decreases with increasing load and speed. The effects of electrical wear are more pronounced in the case of motors with precious metal commutation and vary depending on the nominal voltage of the winding. If required, FAULHABER DC-motors are equipped with integrated spark suppression which minimizes the negative effects of sparking on the service life of the motor.
Mechanical wear of the commutation system depends on the motor speed and increases as the speed rises. Generally, graphite-commutated motors have a longer service life in the case of applications with speeds and loads above the specifications. Additionally, it is important not to exceed the permissible load for the bearing as specified in the data sheet during continuous operation as this could otherwise also have a negative effect on the service life.
Furthermore, the type of motor control also greatly influences the service life. If, for example, a PWM signal is used for control, FAULHABER recommends a minimum frequency of 20 kHz.
Service life of BL motors and stepper motors
Because motor commutation occurs electronically instead of mechanically with brushless motors, the service life is dependent primarily on the service life of the motor bearing. FAULHABER uses mainly highly precise pre-loaded ball bearings.
If brushless motors are operated according to the data sheet, their service life exceeds that of mechanically commutated (brushed) DC motors many times over.
Service life of linear DC-servomotors
The service life of a linear DC-servomotor is influenced primarily by the service life of the sleeve bearings. The wear of these bearings is heavily dependent on the operating speed and the load of the forcer rod.
Service life of gearheads
The service life of a gearhead and of a motor-gearhead combination is dependent on the following factors: input speed, output torque, operating conditions, environment and installation in other systems. Numerous options are available for increasing the service life: ball bearings, exclusively metal gears, special lubrication, etc.
Additional factors that affect the service life of a drive system include the static and dynamic axial and radial bearing loads, the thermal ambient conditions such as extreme humidity and temperature, the speed, vibrational and shock loads as well as the precision with which the shaft is coupled to the given application.
Recommendations
