Electric Actuator: Repetitive Positioning Accuracy of Compact Electric Cylinders

To ensure the repetitive positioning accuracy in the specifications, please note the following points.

①

Securing the Rigidity of the Peripheral Parts

• Use linear guides and other mechanism parts that have rigidity sufficient for the load mass and external force.If the rigidity is insufficient, it may not meet the specifications due to deflection, etc.
• Use mounting brackets for installing the actuator and hardware for connecting the actuator to the load that have rigidity sufficient for the load mass and external force. If the rigidity is insufficient, it may not meet the specifications due to deflection, etc.

②

Sensor

• Use a highly accurate home sensor (such as a photomicrosensor). Repetitive positioning accuracy does not include return-to-home accuracy.

③

Temperature Rise of the Actuator

• The actuator may generate significant heat depending on the driving conditions. This causes the built-in ball screw to extend, resulting in position displacement as shown in the figure below (reference value). To minimize the effect of temperature on the repetitive positioning accuracy, adjust the input current value of the actuator and design the peripheral parts with heat radiation in mind.

Conditions

Current Cutback

OFF

Operating Duty

80 %

Measurement Method

Using a laser displacement meter

[Reference]
Adjusting the input current of the actuator will result in a change in the temperature rise value of the actuator. This is effective when there is allowance in the starting characteristics and holding force.

In addition, reviewing the operating duty also affects the temperature rise value. (The above figure shows a 75 % operating duty.)