Hydraulic Brake Unit Sleeve for Nonrotating Piston Control
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Solution Overview
Problem
Existing hydraulic units for vehicle braking systems, particularly in traction control and external-force braking, face challenges in efficiently building up brake pressure and conveying brake fluid, especially in systems that require precise control and stability.
Innovation Solution
A hydraulic unit featuring a cuboidal metal block with a cylindrical hole and a nonrotatably positioned piston, driven by an electric motor through a planetary gearset and ball screw drive, which includes a sleeve with rotation prevention elements to prevent piston rotation, enabling effective brake pressure generation and fluid conveyance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a piston is used in the hydraulic unit for brake pressure buildup and fluid conveyance, then brake pressure can be generated and brake fluid can be conveyed, but the piston may rotate during operation which compromises control precision and system reliability
Solution Approach 1:
The patent applies preliminary anti-action by incorporating rotation prevention elements (such as keys, splines, or cam mechanisms) into the piston design before operation begins. These elements preemptively counteract any rotational tendency of the piston during hydraulic operation, ensuring the piston moves only in the intended linear direction without rotating, thereby maintaining brake pressure buildup reliability and operational stability
2Measurement precision
If a conventional electric motor with planetary gearset and ball screw drive is used to displace the piston, then precise piston displacement can be achieved, but the device complexity increases due to multiple coaxially arranged components
Solution Approach 1:
The patent merges multiple functional components (electric motor, planetary gearset, ball screw drive, and piston displacement mechanism) into a more integrated configuration. By combining these elements into a unified drive assembly that operates in coordination rather than as separate coaxial stages, the patent reduces overall structural complexity while preserving the precision of piston displacement required for accurate brake pressure control
Solution Approach 2:
The patent implements multi-functionality by designing a drive mechanism that simultaneously performs multiple functions: the electric motor provides rotational power, the gearset provides mechanical advantage and speed reduction, the ball screw converts rotational motion to linear motion, and the entire assembly directly displaces the piston. This multi-functional integration reduces the number of separate components needed while maintaining precise displacement control
3Stability of the object's composition
If a sleeve is added to surround the piston to prevent rotation, then piston rotational stability is improved, but the device complexity increases due to additional components
Solution Approach 1:
The patent merges the rotation prevention function with the piston structure itself by integrating rotation prevention elements (such as keyed connections, splined surfaces, or cam-locked features) directly into the piston design. This integration eliminates the need for a separate surrounding sleeve while maintaining rotational stability, thereby reducing component count and simplifying the overall hydraulic unit structure
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 configuration ensures reliable brake pressure buildup and fluid conveyance, enhancing the performance and control of traction control and external-force braking systems by preventing piston rotation and ensuring precise mechanical and hydraulic interconnections.
Implementation Method 1
the planetary gearset and a ball screw drive. The ball screw drive is disposed coaxially in the piston, which is embodied as a hollow piston. The electric motor is disposed coaxially with the cylindrical sleeve externally on the hydraulic block, and the planetary gearset is disposed, likewise coaxially with respect to the cylindrical sleeve, between the electric motor and the cylindrical sleeve or the ball screw drive.
Implementation Method 2
the planetary gearset and a ball screw drive. The ball screw drive is disposed coaxially in the piston
Implementation Method 3
Displacement of the piston causes brake fluid to be forced or drawn out of the cylindrical hole or cylindrical sleeve, with the result that a brake pressure for actuation of hydraulic wheel brakes connected to the hydraulic block can be built up, and/or brake fluid can be conveyed.
Implementation Method 4
The sleeve serves to prevent rotation of the piston; it has a rotation prevention element which is located between the sleeve and the piston and extends in a displacement direction of the piston, and which holds the piston nonrotatably by positive engagement.
Data Source
AI summary
In order to prevent rotation of a piston of a hydraulic unit of a hydraulic vehicle braking system, a sleeve is provided having axially parallel cylindrical pins constituting rotation prevention elements on its inner circumference, the rear ends of which elements are pressed into axially parallel holes in an inwardly projecting flange of the sleeve, and the front ends of which are inserted into axially parallel blind holes in a diameter step in a mouth of the cylindrical hole in a hydraulic block of the hydraulic unit. A method for assembling the hydraulic unit thus configured is also described.