(1) What is a coupling
One of the mechanical elements that connects the motor and the rotational drive mechanism is the coupling. While introducing advanced digital control devices, the requirements for high precision, high rigidity, and high speed have increased.
(2) Function of coupling
When connecting a rotating motor and a shaft (ball screw, etc.), even if a high-precision connection is possible, the following fluctuations will occur when moving.
(1) Bending of the running axis (ball screw, etc.)
(2) Shaft deformation and deformation stress occur due to thermal expansion of the two shafts
(3) Deformation of the ball screw support part
(4) After long-term use, the frictional resistance will vary due to bearing wear
In order to eliminate the changing factors (1) ~ (4) above, a coupling (flexible shaft joint) is specially used.
(3) Functions that couplings should have
a) High rigidity... In order to cope with the high precision and high speed of the servo system
■ Commentary
If the rigidity of the coupling is small, the servo system is prone to delay (dry running), which may reduce the stopping position accuracy and cause resonance.
b) No gap...in order to cope with the high precision of the servo system
■ Commentary
The clearance (looseness) of the mechanical system is a fatal flaw for the servo system, so a coupling with no sliding parts and no clearance should be selected. Compared with the key transmission method, the shaft fixing method of the coupling is better to adopt the friction fixing method.
c) High and low inertia...in order to improve the responsiveness of the servo system
d) Attenuation characteristics...in order to suppress the vibration of the drive system
(4) New product: Characteristics of high-rigidity disc coupling< /p>
＊Products supporting high-speed, high-precision and excellent controllability servo motors.
＊Because it is a disc type, there is almost no gap caused by high rigidity in the bending direction. In addition, it has high resistance to the axis direction, twist direction, and height direction caused by the adjustment error with the axis. Flexibility, so position adjustment is easier.
＊By adopting the clamping type, shaft machining such as keyway can be omitted, and the strength of the shaft will not be reduced.
■ New product high rigidity disc coupling
