Product Reference - Oriental Motor

3 Obtain the overall equipment rigidity C when a bellows coupling is
used.
1 1 1 1
= + +
C Cm Cb Ct
1 1 1
= + +
90000 116000 334.1
= 0.0030128
C = 331.9 [N·m/rad]
4 Calculation results
Coupling Rigidity
[N·m/rad]
Overall Equipment Rigidity
[N·m/rad]
Jaw Coupling 21000 327.7
Bellows Coupling 116000 331.9
The rigidity of the jaw coupling is one-fifth the rigidity of the bellows
coupling, but the difference in overall equipment rigidity is 1.2%.
■Glossary
●CW, CCW
The rotation direction of motor is expressed as CW (clockwise) or
CCW (counterclockwise). These directions are as seen from the
output shaft.
Counterclockwise CCW
Clockwise CW
●Overhung Load
The load on the motor shaft in the vertical direction. The value varies
with the model.
●Angle Accuracy
The difference between the actual rotation angle and the theoretical
rotation angle. Although there are several expressions according to
how the criteria are set, generally, the angle accuracy of the stepping
motor is expressed in terms of the stop position accuracy.
●Angular Transmission Error
Angular transmission error is the difference between the theoretical
rotation angle of the output shaft, as calculated from the input pulse
number, and the actual rotation angle. It is generally observed when
a reduction mechanism is provided. Angular transmission error is
used to represent the accuracy of a reduction mechanism. Oriental
Motor’s planetary (PN) gear is designed to minimize the angular
transmission error to a maximum of only six arc minutes, and
may be effectively used in high accuracy positioning and indexing
applications.
●Inertial Load (Moment of Load Inertia)
This is the degree of force possessed by a physical object to
maintain its current level of kinetic energy. Every physical object has
an inherent inertial load. Greater torque is required to accelerate
and decelerate an object having a larger inertial load. The degree
of such torque is proportional to the degree of inertial load and
the acceleration that is obtained from the operating speed and
acceleration time.
●Automatic Current Cutback Function
This is a function used for the automatic reduction of motor current
by approximately 50% when the pulse signal is not input, in order to
minimize the heating of the motor and driver.
(Approximately 40% in CMK Series and UMK Series stepping
motors)
This function automatically reduces the motor current at motor
standstill, and does so within approximately 0.1 second after the
pulse signal stops.
Maximum holding torque [N·m (oz-in)] × Current at motor standstill [A]
Holding torque [N·m (oz-in)] =
Rated motor current [A]
●Resonance
This refers to the phenomenon in which vibration becomes larger at
specific speeds. Resonance is a result of the characteristic vibration
frequency and operating vibration of a motor or other mechanism.
For 2-phase stepping motors, there are resonance areas between
100 Hz and 200 Hz; 5-phase stepping motors have lower levels of
resonance.
Technical Reference
Selection
Calculations Service Life
Standard
AC Motors
Speed
Control
Systems
Stepping
Motors Gearheads
Linear
Heads
Linear and
Rotary
Actuators Cooling Fans
F-55