Hydrostatic Transmission Control for Motor Overspeed and Cavitation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydromechanical transmissions face issues such as hydraulic motor overspeeding, pump cavitation, and inefficiencies, leading to motor degradation and constrained torque output.
Innovation Solution
A transmission system with a variable displacement hydraulic motor and pump, coupled in parallel with a gearbox and clutches, maintains a working zone within kinematic and torque constraints to ensure continuous speed ratio and avoid power interruptions during shifts, enhancing efficiency and controllability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional hydromechanical transmission control strategies are used, then the system structure is simple, but hydraulic motor overspeeding occurs which increases motor degradation and decreases motor lifespan
Solution Approach 1:
The patent implements dynamic control of the variable displacement hydraulic motor by continuously adjusting its displacement based on real-time operating conditions. The controller monitors motor speed, pump displacement, and transmission state to dynamically optimize motor performance, preventing overspeeding while adapting to varying load and speed requirements throughout operation.
Solution Approach 2:
The control system incorporates feedback mechanisms where the controller receives information about motor speed, pump displacement, and transmission operating state. Based on this feedback, the controller adjusts motor displacement to maintain optimal operation, preventing harmful overspeed conditions while ensuring reliable motor operation throughout its service life.
2Reliability
If traditional hydromechanical transmission control strategies are used, then the control system is simple, but pump cavitation occurs which causes pump degradation
Solution Approach 1:
The control system performs preliminary actions by proactively adjusting pump displacement and motor displacement before cavitation or overspeeding conditions occur. The controller anticipates potential harmful conditions by monitoring operating parameters and preemptively modifies system state to prevent pump cavitation and motor overspeeding, thereby extending component lifespan.
Solution Approach 2:
The control system incorporates feedback mechanisms where the controller receives information about motor speed, pump displacement, and transmission operating state. Based on this feedback, the controller adjusts motor displacement to maintain optimal operation, preventing harmful overspeed conditions while ensuring reliable motor operation throughout its service life.
3Productivity
If traditional hydromechanical transmission control strategies are used, then the system is easy to operate, but transmission efficiency is reduced and maximum output torque is constrained
Solution Approach 1:
The patent implements dynamic control of the variable displacement hydraulic motor by continuously adjusting its displacement based on real-time operating conditions. The controller monitors motor speed, pump displacement, and transmission state to dynamically optimize motor performance, preventing overspeeding while adapting to varying load and speed requirements throughout operation.
Solution Approach 2:
The control system utilizes parameter changes by dynamically adjusting the displacement of the variable displacement hydraulic motor based on operating conditions. The controller modifies motor displacement parameters in response to varying load, speed, and efficiency requirements, enabling the transmission to achieve maximum output torque and optimal efficiency across different operating states.
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 increases efficiency and reduces the risk of motor degradation by maintaining continuous speed ratio and avoiding pump saturation, improving shifting performance and customer appeal.
Implementation Method 1
a variable displacement hydraulic motor in a hydrostatic assembly. The transmission control scheme may be designed to enable the transmission to reach an upper bound (e.g., maximum) of transmission output torque
Data Source
AI summary
Methods and systems for transmission control are provided. In one example, a transmission system operating method includes maintaining a displacement set-point of a variable displacement hydraulic motor in a hydrostatic assembly within a working zone, where at least a portion of a boundary of the working zone is determined based on a kinematic constraint of the hydrostatic assembly. The transmission system includes the hydrostatic assembly that includes the variable displacement hydraulic motor that is hydraulically coupled in parallel with a variable displacement hydraulic pump and a gearbox mechanically coupled to the hydrostatic assembly and including one or more clutches.