Electric Booster Offset Axis Spherical Connection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric boosters face reliability issues due to unnecessary moment and radial loads applied to linear motion members caused by errors in component assembly, particularly when using a rotation-linear motion conversion mechanism configured on a different axis from the input rod.
Innovation Solution
The electric booster design includes a thrust force transmission member that is swingably connected to nut members and an output member, with a rotation-linear motion conversion mechanism having a rotational axis offset from the master cylinder's central axis, and employs an elastic member to absorb offset loads, preventing unnecessary moments and radial loads on threaded shaft members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a rotation-linear motion conversion mechanism is configured on a different axis from the input rod, then the device size can be reduced, but unnecessary moment and radial load are applied to linear motion members due to assembly errors, reducing reliability
Solution Approach 1:
The patent employs a spherical connection between the thrust force transmission member and the nut member, allowing angular adjustment to compensate for assembly errors. The spherical interface enables the linear motion member to self-align and eliminate unnecessary moments and radial loads while maintaining the offset axis configuration for compact size.
2Volume of moving object
If a ball screw mechanism is used for rotation-linear motion conversion, then the structure is compact, but the layout is restricted due to coaxial requirement with input rod, making size reduction difficult
Solution Approach 1:
The patent transitions from a coaxial arrangement to an offset axis configuration by introducing a spherical connection interface. This dimensional change in the connection geometry allows the rotation-linear motion conversion mechanism to be positioned at a different axis while maintaining compact size and improving layout flexibility.
3Device complexity
If traditional rigid connections are used between thrust force transmission member and nut members, then structural simplicity is maintained, but assembly errors cause unnecessary moments and radial loads reducing reliability
Solution Approach 1:
The spherical connection interface provides angular adjustment capability that compensates for assembly errors without significantly increasing structural complexity. The spherical geometry naturally accommodates misalignment while maintaining a relatively simple connection structure compared to multi-component adjustment mechanisms.
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 enhances the reliability and efficiency of the electric booster by preventing transmission efficiency reduction and nut member sticking, while allowing for a more compact and cost-effective design by using trapezoidal screws instead of expensive ball screws.
Implementation Method 1
The thrust force transmission member is connected to at least one of the nut members and the output member via an elastic member
Data Source
AI summary
An electric booster includes an input member configured to be moved forward or rearward according to an operation on a brake pedal, a thrust force transmission member provided movably relative to the input member, an electric actuator configured to move the thrust force transmission member forward or rearward, and an output member connected to the thrust force transmission member and configured to transmit a thrust force provided from the electric actuator to the thrust force transmission member to a piston of a master cylinder. The electric actuator includes an electric motor, at least two threaded shaft members configured to be rotationally driven by the electric motor, and nut members respectively meshed with the threaded shaft members. Each of the nut members is connected to the thrust force transmission member. The thrust force transmission member is swingably connected to at least one of the nut members and the output member.