Miki Pulley COUPLINGS, Manual

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T h e l a te s t CA D d a t a c a n b e d ow n l o a d e d f r o m o u r we b s i te.
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The CAD mark indicates that CAD data is available by CD-ROM.
The CAD file No. represents the file name in the CD-ROM.
C A D
C A D
S
E
R
V
O F
L
E
X
S
F
H
Motor
Feed
screw
Bearing
Table Coupling
¢
Selection procedure ¢
How to evaluate the eigenfrequency of
feed-screw system
(1) Calculate torque Ta applied to the coupling based on the
motor output P and coupling operating rotation speed n.
In servo motor drive, multiply the service factor K=1.2 to 1.5 by
the maximum torque of servo motor Ts.
(1) Select the coupling according to the normal operating torque
and maximum torque of the servo motor/stepping motor. (See
the selection procedure on the left.)
J1 J2
Load character
Constant Fluctuations: Slight Fluctuations: Medium Fluctuations: Large
1.0 1.25 1.75 2.25
(2) Calculate corrected torque Td applied to the coupling after
deciding the service factor K based on load conditions.
(3) Select the size in order that the coupling permissible torque
Tn becomes equal or greater than the corrected torque Td.
(4) Depending on the bore diameters, the coupling permissible
torque may be limited. Refer to the “Specification” and
“Standard bore diameter.”
(5) Confirm if the required shaft diameter does not exceed the
maximum bore diameter of the coupling.
¢
Feed-screw systems
ò
Oscillation phenomena of servo motors
If the eigenfrequency of the entire feed-screw system is under
400 to 500Hz, oscillation may occur depending on the gain
adjustment of the servo motor. An oscillation phenomenon
of a servo motor occurs mainly by the problem of the
eigenfrequency of the entire feed-screw system and the
electric control system.
These problems can be avoided by raising the eigenfrequency
of the mechanical system from the design phase or adjusting
the tuning function (filter function) of the servo motor.
ò
Resonance caused by stepping motors
It is a phenomenon that occurs within a certain rotation speed
range by the pulsation frequency of the stepping motor and
the eigenfrequency of the entire system. Resonance can be
avoided by not applying the resonant rotation speed, or by
reviewing the eigenfrequency in the design phase.
Contact us for unclear points concerning ocsillation phenomena
of servo motors and resonance of stepping motors.
(2) In the following feed-screw system, evaluate the entire
eigenfrequency: Nf from the torsional stiffness: K of the
coupling and feed screw, the moment of inertia: J1 of the
driving side and the moment of inertia: J2 of the driven side.
For machines whose load torques periodically fluctuate
drastically, contact us.
Design Check Items
SFH MODEL
Nf: Eigenfrequency of the entire feed-screw system [Hz]
k : Torsional
stiffness
of the coupling and feed screw [N·m/rad]
J1: Moment of inertia of the driving side [kg·m 2 ]
J2: Moment of inertia of the driven side [kg·m
2
]
Td = Ta × K (see below)
Ta [N·m] = 9550 ×
P [kW]
n [min
−1
]
Td = Ts × (1.2 to 1.5)
Tn
≥
Td