Gear Pump Torque Modulation for Tooth Engagement Noise Control
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Solution Overview
Problem
Differential pressure-regulated gear pumps in motor vehicle chassis hydraulics experience sinusoidal fluid flow fluctuations due to tooth engagement, leading to noise issues that negatively impact the driving experience.
Innovation Solution
A method using a control device with an acquisition unit, computing device, and memory device to modulate a pilot control torque based on gear angle, actual speed, and tooth count, compensating for volume flow pulsations by overlaying the modulated torque onto the drive torque of the gear pump, thereby reducing fluid flow fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a gear pump is used to convey fluid in chassis hydraulics, then fluid transport function is achieved, but sinusoidal pressure fluctuations occur due to tooth engagement causing noise
Solution Approach 1:
The control device applies a counteracting torque to the drive shaft that is precisely timed and sized to compensate for the pressure fluctuations caused by tooth engagement. By predicting the fluctuation pattern based on gear angle and speed, the system applies an opposing force in advance to cancel out the harmful pressure variations, thereby reducing noise while maintaining fluid transport function
Solution Approach 2:
The system dynamically adjusts the drive torque based on real-time operating conditions including actual speed, gear angle, and predetermined correction angles. The control device continuously modulates the pilot control torque to adapt to changing operational parameters, ensuring optimal noise compensation across varying speed ranges and load conditions
2Adaptability or versatility
If the gear pump operates at varying speeds, then adaptability to different driving conditions is improved, but the relationship between modulation angle and speed becomes complex requiring extensive calibration data
Solution Approach 1:
The system transforms the complex two-dimensional relationship between modulation angle and speed into a more manageable form by introducing a predetermined correction angle as a third parameter. This correction angle, determined during calibration, allows the system to quickly adjust for speed variations without requiring a complete recalibration of the modulation angle, thereby simplifying the data structure while maintaining adaptability across different operating conditions
Data Source
AI summary
A method for controlling a gear pump by a control device to compensate a tooth engagement-induced volume flow pulsation to reduce noise emissions. The method includes acquiring a gear angle and an actual speed of the gear pump; keeping a relationship between a respective modulation angle and an amplitude of a pilot control torque of the gear pump to compensate the volume flow pulsation to an actual speed; modulating the pilot control torque on the basis of the acquired gear angle, a predetermined correction angle, the modulation angle, a number of teeth of the gear pump and the amplitude; and driving the gear pump with a drive torque overlaid with the modulated pilot control torque. The modulation angle is calculated using a PT element with the actual speed as the input variable.