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 pressure fluctuations due to tooth engagement, leading to noise that negatively impacts the driving experience.
Innovation Solution
A method for controlling a gear pump using a control device with an acquisition unit, computing device, and memory device to modulate a pilot control torque, compensating tooth engagement-induced volume flow pulsations by adjusting the gear angle, modulation angle, and amplitude based on the actual speed of the gear pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gear pump is used to convey fluid in chassis hydraulics, then the pump provides reliable fluid delivery, but tooth engagement causes sinusoidal fluid flow fluctuations that generate noise
Solution Approach 1:
The patent applies periodic action by introducing a modulated pilot control torque that oscillates at the same frequency as the tooth engagement-induced flow fluctuations. This periodic torque modulation creates compensating speed variations in the gear pump that counteract the sinusoidal flow pulsations, thereby reducing noise while maintaining reliable fluid delivery
Solution Approach 2:
The patent implements feedback by using an acquisition unit to continuously monitor the actual speed of the gear pump and comparing it with the desired speed profile. The control device then adjusts the pilot control torque based on this feedback to compensate for flow fluctuations caused by tooth engagement, creating a closed-loop control system that actively reduces noise
2Productivity
If the gear pump operates at higher speeds to increase productivity, then fluid flow rate increases, but the amplitude of tooth engagement-induced fluctuations also increases
Solution Approach 1:
The patent applies dynamics by making the pilot control torque adaptive to the operating speed of the gear pump. The control device continuously adjusts the amplitude and phase of the modulated pilot torque based on the actual speed feedback, allowing the system to effectively compensate for flow fluctuations across a wide range of operating speeds and maintaining low noise levels even at high productivity 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.