Motor Gear Drive Harmonic Control for Torque Ripple Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drive apparatuses with clutches to synchronize the phase of a rotor's magnetic pole and gear meshing to suppress vibration increase cost and weight, necessitating a solution that does not rely on clutches.
Innovation Solution
A drive apparatus with a gear whose number of teeth is set to coincide with the order of torque ripple in the electric motor, using harmonic superposition control on the drive current to reduce vibration when the magnitude exceeds a threshold, without increasing cost or weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a clutch is used to synchronize the phase of the rotor's magnetic pole and gear meshing to suppress vibration, then vibration suppression is improved, but device complexity, cost, and weight increase
Solution Approach 1:
The invention extracts and eliminates the clutch component from the system by using a different approach - setting the gear tooth number to a specific value that creates a predetermined phase relationship between torque ripple and meshing torque fluctuation, thereby suppressing vibration without requiring a clutch
Solution Approach 2:
The invention changes the parameter of gear tooth number to a specific value that satisfies a predetermined relationship with the number of pole pairs, which automatically creates the desired phase opposition between torque ripple and meshing torque fluctuation, eliminating the need for active phase control via clutch
2Object-affected harmful factors
If a clutch is used to synchronize the phase of the rotor's magnetic pole and gear meshing to suppress vibration, then vibration suppression is improved, but cost increases
Solution Approach 1:
The invention removes the clutch component entirely and replaces it with a gear tooth number selection that passively achieves vibration suppression through its geometric parameter, eliminating the cost associated with clutch manufacturing and assembly
Solution Approach 2:
By changing the gear tooth number to a specific value based on the relationship with pole pairs, the invention achieves vibration suppression through a simple geometric parameter adjustment that is cost-effective compared to implementing an active clutch mechanism
3Object-affected harmful factors
If a clutch is used to synchronize the phase of the rotor's magnetic pole and gear meshing to suppress vibration, then vibration suppression is improved, but weight increases
Solution Approach 1:
The invention extracts and removes the heavy clutch component from the system, replacing it with a lightweight solution based on gear tooth number selection that achieves the same vibration suppression function without additional weight
Solution Approach 2:
By adjusting the gear tooth number parameter to satisfy the predetermined relationship with pole pairs, the invention achieves vibration suppression through a passive geometric configuration that adds no significant weight compared to implementing an active clutch mechanism
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Suppresses vibration and noise while maintaining cost and weight efficiency by aligning gear tooth order with torque ripple order and applying harmonic superposition control.
Implementation Method 1
the control device is configured to execute a harmonic superposition control for superposing a harmonic current on a fundamental wave of the drive current such that the magnitude of the vibration of the gear is reduced
Data Source
AI summary
A drive apparatus includes: (a) an electric motor including a rotor and a stator that has a stator core and a stator coil; (b) a gear connected to a shaft of the rotor; and (c) a control device configured to control a drive current flowing through the stator core. The gear has a number of teeth which makes an order of a fluctuation of a meshing torque generated in the gear coincide with an order of a torque ripple generated in the electric motor. When a magnitude of vibration of the gear caused by the torque ripple and the fluctuation of the meshing torque exceeds a predetermined determination value, the control device is configured to execute a harmonic superposition control for superposing a harmonic current on a fundamental wave of the drive current such that the magnitude of the vibration of the gear is reduced.