Hydraulic Linear Displacement Limiter for Manual-Feel Gear Shifting

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Solution Overview

Problem

Existing manual transmissions require direct driver input for gear shifting, which can be cumbersome, while automatic transmissions lack the precise control and feel of mechanical transmissions.

Innovation Solution

A linear-displacement limiter system using a hydraulic cylinder, conduit, valve, and actuator to emulate a mechanical transmission, allowing precise and fast control of stick-shifter and clutch-pedal arrangements in automatic transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a manual transmission is used, then the driver has direct control over gear shifting, but the operation becomes cumbersome and less convenient

Engineering Contradiction:
Improvegear shifting convenienceVSAvoidtransmission control mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the purely mechanical manual transmission control system with a hybrid system that uses a hydraulic cylinder and actuator to provide automated assistance. The actuator controls the position of the gear stick or clutch pedal through hydraulic pressure, reducing the physical effort required while maintaining precise control capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a hydraulic cylinder filled with hydraulic fluid to generate and control the mechanical force needed for gear shifting. The hydraulic system provides smooth, controlled movement of the gear stick or clutch pedal, combining the convenience of automated control with the precision of mechanical transmission.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Ease of operation

If an automatic transmission is used, then gear shifting is automated and convenient, but the control precision and driver engagement are reduced

Engineering Contradiction:
Improvegear shifting automationVSAvoiddisplacement control accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent incorporates sensors that detect the position of the gear stick or clutch pedal and provide feedback to the control system. This feedback mechanism allows the actuator to make precise adjustments to maintain the desired position, ensuring accurate displacement control while keeping the system automated.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses a dynamic control system where the actuator can adjust its output force and position in real-time based on driving conditions. The hydraulic system responds dynamically to control signals, allowing precise modulation of the gear stick or clutch pedal position rather than fixed, discrete positions.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If a hydraulic limiter system is added to an automatic transmission, then control precision is improved, but the device complexity increases

Engineering Contradiction:
Improvedisplacement limitation accuracyVSAvoidhydraulic control system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the hydraulic limiting function with the existing automatic transmission control system. The hydraulic cylinder serves dual purposes: it provides the force for gear shifting and simultaneously limits the displacement to prevent excessive movement. This integration reduces the need for separate limiting mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The actuator and hydraulic system are designed to perform multiple functions: they provide automated gear shifting, control the position precision, and limit the maximum displacement. This multi-functionality reduces the overall system complexity compared to having separate systems for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enables precise and fast control of automatic transmission systems, mimicking the feel of manual transmissions by limiting and damping linear displacements for improved gear shifting.

Implementation Method 1

The hydraulic cylinder and the hydraulic conduit is filled with the hydraulic fluid. The hydraulic conduit is arranged to allow a flow of the hydraulic fluid directly between the first chamber and the second chamber.

Methodology Applied
Scientific EffectHydraulic pressure transmission: Pascal's Law

Implementation Method 2

The proposed linear-displacement limiter allows for a precise and fast control of stick-shifter arrangements and clutch-pedal arrangements

Methodology Applied
Scientific EffectHydraulic damping: Viscous Damping

Data Source

PatentEP4667785A1Linear displacement limiter and applications thereof
Publication Date: 2025.12.24 KOENIGSEGG AUTOMOTIVE AB
  • EP4667785A1 patent drawingFigure 1a~1b
  • EP4667785A1 patent drawingFigure 2a~2b
  • EP4667785A1 patent drawingFigure 3

AI summary

A linear-displacement limiter (10) is proposed that has: a hydraulic cylinder (12), a hydraulic conduit (24), a valve (28), an actuator (26), and a hydraulic fluid. The hydraulic cylinder (12) is a double-action cylinder and has a hydraulic first chamber (14), a hydraulic second chamber (16), and a piston (18) that separates the first chamber (14) and the second chamber (16). The hydraulic cylinder (12) further has a first rod (20) that is connected to the piston (18) via the first chamber (14) and a second rod (22) that is connected to the piston (18) via the second chamber (16). The hydraulic cylinder (12) and the hydraulic conduit (24) is filled with the hydraulic fluid, and the hydraulic conduit (24) is arranged to allow a flow of the hydraulic fluid directly between the first chamber (14) and the second chamber (16). The valve (28) is arranged to regulate a flow of the hydraulic fluid between the first chamber (14) and the second chamber (16), and the actuator (26) is arranged to operate the valve (28).