When building precision transmission systems, the matching selection of servo motors and rotary splines directly determines the overall equipment stability. Many projects leave hidden dangers by only matching parameters from a single dimension. Only two-way verification based on rated torque and maximum speed can avoid common transmission failure pitfalls.
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Static Verification of Load Torque and Motor Rated Torque
Calculate the equivalent load torque according to the continuous working load borne by the rotary spline. This value must be lower than the motor’s rated torque with sufficient safety margin to cope with instantaneous overload caused by material hardness fluctuation or lubrication attenuation, preventing motor overheating during steady operation.
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Dynamic Verification of Peak Torque under Acceleration & Deceleration Conditions
For startup, stop or speed switching phases, calculate the vector sum of inertial torque and load torque generated by the spline. The peak torque must fall within the allowable instantaneous maximum output range of the motor. Meanwhile, verify the torsional rigidity of the spline to avoid plastic deformation, and match the acceleration time with motor inertia to prevent step loss.
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Resonance Avoidance: Maximum Speed vs Spline Critical Speed
The maximum operating speed of the motor shall be lower than the first-order torsional critical speed of the rotary spline with a certain margin reserved. In addition, calculate the influence of centrifugal force of balls or spline sleeves on preload at this speed, ensuring contact stress does not exceed the material fatigue limit to prevent abnormal wear at high speed.
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Comprehensive Safety Margin under Bidirectional Compound Working Conditions
When switching forward and reverse rotation frequently, verify whether the torque and speed combinations of both rotation directions are within the allowable working range of the motor and spline. Special attention shall be paid to the influence of backlash on control accuracy, and whether the regenerative braking power of the motor during rapid reversal exceeds the absorption capacity of the driver.
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Derating Correction of Continuous Performance by Heat Dissipation & Lubrication
Derate the motor’s rated torque according to the actual duty cycle and maximum ambient temperature, and calculate the oil film temperature rise of the spline at high speed. Check whether the viscosity change of lubricant at high temperature leads to a sharp rise in friction torque, and adjust the model selection if necessary to guarantee stable bidirectional performance in full temperature range.
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