2.7.5 Mounting Ball Screw Spline Unit
• The ball screw spline unit should be replaced with a new one only after the
controller power is turned off with the power supply plug removed. If the work
is done while the power is turned on, you may get an electric shock or the robot
may malfunction, which is very dangerous.
• Handle the ball screw spline unit with extreme care. If the unit drops or an
unusually large external force is exerted on it, it cannot function any further.
• Replacement of the ball screw spline
unit involves mounting and dismounting of
the axis 3 and 4 motors and timing belts. Also observe the cautions on each
work.
• Because the motor, timing belt, nut and pulley are disconnected, the
mechanical home point shifts and proper control cannot be done. To avoid
this, home return operation is necessary after replacement of the ball screw
spline unit. For the home return procedures, see Section 4.
• DO NOT pull out the ball screw shaft from the ball screw nut. Otherwise, the
ball in the ball screw nut will drop and the ball screw nut integrated with the ball
screw shaft cannot function any further.
1) Disconnect the ball spline nut from the new ball screw spline unit.
2) Secure the ball spline nut to the arm 2 with six (6) low head bolts (M5 × 16).
The clamping torque of each low head bolt is 5.7 N·m.
As the hole on each low head bolt, which is intended for using a wrench, is
shallow, take care to handle the wrench.
3) Mount the axis 4 nut pulley on the ball spline nut with the six (6) bolts (M5 × 10).
At this time, the pulley will rotate and cannot be secured easily. Tighten the
bolts only after the axis 4 motor is mounted.
STE 85306
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