3 Specifications and External Dimensions for Motors3.2.5 Allowable Load Moment of Inertia at the Motor Shaft3-223.2.5 Allowable Load Moment of Inertia at the Motor ShaftThe rotor moment of inertia ratio is the value for a servomotor without a holding brake.The larger the load moment of inertia, the worse the movement response of the load.The allowable load moment of inertia (J L ) depends on the motor capacity, as shown below. This value is pro-vided strictly as a guideline and results may vary depending on servomotor drive conditions.An overvoltage alarm (A.400) is likely to occur during deceleration if the load moment of inertia exceeds theallowable load moment of inertia. Take one of the following steps if an overvoltage alarm occurs.• Reduce the torque limit.• Reduce the deceleration rate.• Reduce the maximum speed.3.2.6 Allowable Radial and Thrust LoadsDesign the mechanical system so thrust and radial loads applied to the servomotor shaft end during operationfall within the ranges shown in the table.Servomotor Model ServomotorRated OutputAllowable Load Moment of Inertia(Rotor Moment of Inertia Ratio)SGMGV-05 to -75 0.45 to 7.5 kW 5 timesServomotor ModelAllowableRadial LoadFr (N)AllowableThrust LoadFs (N)LF(mm) Reference DiagramSGMGV-05 490 98 40SGMGV-09 490 98 58SGMGV-13 686 343 58SGMGV-20 980 392 58SGMGV-30 1470 490 79SGMGV-44 1470 490 79SGMGV-55 1764 588 113SGMGV-75 1764 588 113FrFsLF
