Ball Screw Braking Device Solid Spindle Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing brake devices for hydraulic motor vehicle brake systems are complex, expensive to produce, and heavy due to the need for a large-diameter piston rod and hollow spindle, while also requiring direct driver intervention in case of failures, which complicates the design and increases costs.
Innovation Solution
A brake device with a ball screw having an outer pot with external teeth driven by a belt or gear drive, where the ball screw nut is secured against rotation and has a non-round outer contour, allowing direct driver intervention without a cost-intensive hollow spindle, using a lighter solid spindle and adjustable spring elements for haptic feedback, and incorporating a sensor device for position detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a hollow spindle with a long piston rod is used to allow direct driver access to the cylinder piston, then direct driver intervention is enabled, but the radial expansion, weight, and manufacturing cost increase significantly
Solution Approach 1:
The invention separates the functions of the spindle: the solid spindle only transmits force, while a separate piston rod (extending through the amplifier housing) provides direct driver access. This segmentation eliminates the need for a hollow spindle, reducing weight and manufacturing cost while maintaining both amplification and direct access capabilities
Solution Approach 2:
The piston rod acts as an intermediary element that bridges the gap between the driver's pedal input and the cylinder piston, allowing direct force transmission without requiring the spindle to be hollow. The reaction force is transmitted through this intermediary structure, enabling direct driver intervention while using a simpler solid spindle
2Ease of operation
If a hollow spindle is used to allow direct driver access, then driver intervention is possible, but manufacturing cost increases due to the complexity of manufacturing hollow spindles
Solution Approach 1:
The invention divides the force transmission function from the access function: the solid spindle handles force transmission from the ball screw mechanism, while a separate piston rod provides the access path for direct driver intervention. This segmentation uses standard solid shaft manufacturing processes, eliminating the costly hollow spindle manufacturing process
Solution Approach 2:
The invention replaces the expensive hollow spindle with a combination of a simple solid spindle and a separate piston rod, using cheaper, easier-to-manufacture components that achieve the same functional result
3Strength
If a large outer diameter piston rod is used to ensure sufficient rigidity, then rigidity is improved, but the radial expansion increases, increasing the size of the hollow spindle and overall dimensions
Solution Approach 1:
The invention separates the rigid force transmission function (handled by the solid spindle with adequate diameter for rigidity) from the access function (handled by the piston rod). This allows the solid spindle to be optimized for rigidity without the constraint of needing to accommodate a hollow passage, reducing the required radial space
Solution Approach 2:
The invention resolves the spatial conflict by extending the piston rod axially through the amplifier housing rather than requiring radial space for a hollow spindle. This dimensional reorganization allows the solid spindle to maintain necessary rigidity with smaller radial dimensions
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 solution reduces the radial expansion and weight of the amplifier stage, allows for cost-effective and adaptable haptic feedback, and simplifies the design by eliminating the need for a hollow spindle, enabling efficient and direct driver intervention while maintaining comfortable pedal feedback.
Implementation Method 1
A braking device with a ball screw drive is known from DE 10 2008 038 320 A1. The amplifying force is introduced into the cylinder piston by a hollow spindle of the ball screw drive.
Implementation Method 2
The amplifier stage is driven by a drive unit with a rotating drive shaft and uses a ball screw drive to convert the rotary motion of the drive shaft into a translational motion
Implementation Method 3
the ball screw drive has an outer pot with external teeth, which is set in rotation by the drive unit via the external teeth - for example by means of a belt drive or gear drive
Implementation Method 4
the ball screw drive has an outer pot with external teeth, which is set in rotation by the drive unit via the external teeth - for example by means of a belt drive or gear drive
Data Source
Figure 1
Figure 2a
Figure 2b
AI summary
The invention relates to a braking device (1) for a hydraulic motor vehicle braking system having an electromagnetically driven amplifier stage (2) and a ball screw drive (5). In order to provide a braking device (1) that is particularly compact, cost-effective, and has low weight, short pedal strokes, and an easily adjustable pedal characteristic curve, at the same time enabling effective direct action in case of failure of the amplifier stage and comfortable haptic response on the pedal during normal operation, according to the invention, the actuating force (Fb) from a piston rod (10) is introduced into the spindle (7), wherein the piston rod (10) is movable relative to the spindle (7) in an axially limited manner and a spring element (11) is connected in the flow of force of the actuating force (Fb) between the piston rod (10) and the spindle (7), which is axially compressed upon initiation of the actuating force (Fb).