Single Control Valve for Hydrodynamic Retarder Torque Regulation
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Solution Overview
Problem
Conventional hydrodynamic machine control systems, such as retarders, require two valves for power and torque control, leading to increased complexity and a high minimum power transmission or braking torque, which cannot be reduced below a certain level.
Innovation Solution
A single control valve with multiple inlets and outlets is used, employing a force transducer and displacement transducer to control the working medium flow, allowing for adjustable power transmission and braking torque from zero, eliminating the need for high minimum power transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If two separately controlled valves (switching valve and control valve) are used to control the hydrodynamic machine, then the power transmission and braking torque can be regulated, but the control complexity increases and a high minimum braking torque is specified
Solution Approach 1:
The patent combines the switching valve and control valve into a single control valve with a valve body that has multiple inlet and outlet openings. This single valve integrates the functions of both the switching valve (which routed flow completely to or past the retarder) and the control valve (which regulated pressure in the working chamber), thereby reducing the number of components and control complexity while maintaining full control capability over power transmission and braking torque from zero to maximum
2Device complexity
If a switching valve with only on and off states is used, then the system is simple, but a minimum power transmission or minimum braking torque is specified that cannot be fallen below
Solution Approach 1:
The control valve incorporates a valve piston that can assume multiple positions between fully closed and fully open states, enabling continuous adjustment of the working medium flow to the hydrodynamic machine. This dynamic positioning capability allows the braking torque and power transmission to be adjusted uniformly from zero to maximum, eliminating the fixed minimum torque limitation of binary switching valves while maintaining structural simplicity
3Stress or pressure
If a compression spring with sufficiently large spring force is used in the control valve, then high pressures in the working chamber can be regulated, but the preload force increases leading to high minimum pressure and high minimum braking torque
Solution Approach 1:
The control valve uses a valve piston with multiple sealing elements that create separate control zones. By segmenting the control function across multiple sealing surfaces and control edges, the system can regulate high working chamber pressures without requiring excessive spring force, as each sealing element manages a specific pressure zone. This segmentation allows the spring force to be optimized for normal operation while preventing the generation of high minimum braking torque
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
This solution simplifies the control complexity of hydrodynamic machines, enabling uniform increase in braking torque or power transmission starting from zero, and allows for precise regulation of pressures in the working chamber, reducing the high minimum braking torque typically required in conventional systems.
Implementation Method 1
A single control valve with multiple inlets and outlets is used, employing a force transducer and displacement transducer to control the working medium flow
Implementation Method 2
This preload force is generated, for example, by a compression spring that compresses the valve piston pushed to its closed position
Implementation Method 3
The opening state of the control valve is regulated or controlled via a single control pressure
Data Source
Figure 1~3
AI summary
The invention relates to a filling control device of a hydrodynamic machine, in particular for a retarder: having a first inlet (1) for supplying working medium for the hydrodynamic machine into the filling control device; having a second inlet (2) for supplying working medium from the hydrodynamic machine into the filling control device; having a first outlet (3) for discharging working medium into the hydrodynamic machine; having a second outlet (4) for discharging working medium from the hydrodynamic machine or working medium from a bypass (10) which carries working medium past the hydrodynamic machine; having a force transducer and/or displacement sensor or a port for such a sensor. The invention is characterized by the fact that all the aforesaid inlets and outlets together with the force transducer and/or displacement sensor or the port (5) for such a sensor are provided in a common control valve which has a first valve body or piston (6) on which the force transducer and/or displacement sensor acts in such a way that it at least indirectly carries out open-loop or closed-loop control on the flow of working medium in the inlets and outlets and/or between them as a function of the action of the force transducer and/or displacement sensor.