Dual-Motor Hydraulic Pump Control for Stable Vehicle Hydraulics
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Solution Overview
Problem
Existing hydraulic systems in vehicles, particularly heavy-duty vehicles, often rely on internal combustion engines to drive hydraulic pumps, which is undesirable, and using a single large motor can lead to stability issues and higher costs.
Innovation Solution
A hydraulic system utilizing two electric motors, each controlled independently to run at a reference speed or deliver a reference torque, with a control arrangement to manage their operation based on hydraulic supply requests, ensuring stability and cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single large motor is used to drive the hydraulic pump, then the system structure is simpler, but stability issues occur and costs increase
Solution Approach 1:
The patent divides the single large motor function into two smaller motors. Each motor is controlled independently to either run at reference speed or deliver reference torque, avoiding the stability issues associated with a single large motor while maintaining the ability to drive the hydraulic pump effectively.
2Speed
If both motors are controlled to run at reference speed, then speed control is improved, but resonance and stability issues occur
Solution Approach 1:
The control system dynamically switches between different control modes (speed control and torque control) based on system conditions. This dynamic adjustment prevents resonance by avoiding simultaneous speed control of both motors, which would cause instability, while still achieving effective speed control when needed.
3Ease of manufacture
If two smaller motors are used instead of one large motor, then costs are reduced and redundancy is increased, but control complexity increases
Solution Approach 1:
Each motor is designed with multi-functionality, capable of operating in both speed control mode and torque control mode. This universal capability simplifies the overall control architecture compared to using specialized motors for each function, as the same motor hardware can adapt to different control requirements based on system needs.
4Productivity
If one motor is controlled to run at reference speed and the other to deliver reference torque, then hydraulic supply requests are quickly and reliably delivered, but individual motor control complexity increases
Solution Approach 1:
The control system ensures continuous and reliable hydraulic supply by having one motor dedicated to speed control (maintaining continuous rotation) and the other to torque control (providing continuous force). This division of labor ensures that both speed and torque requirements are met simultaneously without interruption, achieving quick and reliable response to hydraulic supply requests.
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
The system provides improved hydraulic pump control, reduced costs, and increased redundancy by using two smaller motors, allowing quick and reliable responses to various hydraulic demands while minimizing interference and wear.
Implementation Method 1
a first electric motor, a second electric motor, a gearbox arranged to be driven by the first and second electric motors
Data Source
AI summary
A hydraulic system for a vehicle is provided. The hydraulic system includes a first electric motor, a second electric motor, a gearbox arranged to be driven by the first and second electric motors, a hydraulic pump arranged to be driven by the gearbox, and a control arrangement configured to individually control the first and second electric motors to either run at a reference speed or to deliver a reference torque and during operation control at least one of the first and second electric motors to deliver a reference torque.