Disc Brake Ball Screw Layout With Internal Thrust Bearing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing actuation devices for disc brakes, particularly electromechanical disc brakes, suffer from large axial dimensions and increased unsprung weight, which hinder vehicle design and dynamics, leading to higher energy consumption and CO2 emissions.
Innovation Solution
The actuation device features a recirculating ball screw-nut screw assembly with a thrust bearing positioned within the axial extension of the threaded shaft, reducing axial dimensions by eliminating the need for a thrust bearing at the rear end of the threaded shaft and integrating the force sensor within the axial dimension of the threaded shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a thrust bearing and torque transmission system are allocated at the rear end of the threaded shaft, then the actuation device can transmit the torque generated by the gearmotor, but the axial dimension of the actuation device increases
Solution Approach 1:
The thrust bearing (8) is integrated within the axial extension of the threaded shaft (4) rather than being positioned at the rear end, merging the thrust support function with the existing axial space. This combining of functions reduces the overall axial dimension while maintaining torque transmission capability through the nut screw (5) and threaded shaft (4) assembly.
Solution Approach 2:
The thrust bearing is repositioned from a rear-end axial arrangement to an integrated position within the threaded shaft's axial extension. This dimensional reorganization allows the thrust bearing to occupy space that would otherwise be within the threaded shaft's length, effectively reducing the total axial dimension of the actuation device while maintaining all necessary functions.
2Force
If the actuation device is installed directly on the axial joint of the vehicle, then it can provide braking force, but the unsprung weight of the vehicle increases
Solution Approach 1:
The actuation device integrates multiple functions including the gearmotor (7), recirculating ball screw-nut screw assembly (3), and thrust bearing (8) into a compact unit. This merging of components achieves the braking force generation while minimizing the overall weight of the unsprung assembly by eliminating redundant structures and optimizing component layout.
3Reliability
If the axial dimension of the actuation device is large, then the thrust bearing and torque transmission system can be properly accommodated, but the wheel joint design is hindered and maximum steering is limited
Solution Approach 1:
The thrust bearing is repositioned within the threaded shaft's axial extension rather than at the rear end, effectively utilizing the internal axial space. This dimensional reorganization reduces the overall axial footprint of the actuation device, thereby providing greater design flexibility for the wheel joint and enabling maximum steering angles without compromising thrust bearing accommodation.
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 results in a significantly reduced axial dimension and weight of the actuation device, improving vehicle dynamics, reducing energy consumption, and lowering CO2 emissions while maintaining or enhancing braking efficiency.
Implementation Method 1
a gearmotor (7) associated with a recirculating ball screw-nut screw assembly, formed by a threaded shaft (4) and a nut screw (5), which converts the torque generated by the gearmotor (7) into a braking force directed against the disc brake pads
Implementation Method 2
recirculating ball screw-nut screw assembly
Implementation Method 3
positioned within the extension of the threaded shaft (4) between a front end and a rear end of the threaded shaft (4)
Data Source
AI summary
An actuation device for a brake disc has a recirculating ball screw-nut screw assembly and a thrust bearing. The recirculating ball screw-nut screw assembly has a threaded shaft and a nut screw screwed onto the threaded shaft. The threaded shaft and the nut screw extend in direction of an actuation axis. The threaded shaft extends between a front end and a rear end of the threaded shaft. The nut screw receives a torque generatable by a gearmotor. A rotation of the nut screw with respect to the threaded shaft results in a translation of the threaded shaft with respect to the nut screw in the direction of the actuation axis. The thrust bearing provides a reaction rest for the nut screw in the direction of the actuation axis. The thrust bearing is positioned within an extension of the threaded shaft between the front and rear ends of the threaded shaft.