Gearbox Clutch Ratchet Assembly Noise Reduction
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Solution Overview
Problem
Automated transmission systems, particularly dual-clutch transmissions, experience noise issues due to shift clicking caused by the relative movement of components at high speeds, which can lead to annoying switching sounds for drivers.
Innovation Solution
A latching arrangement is designed with a coordinated spring property, latching contour shape, and transition angles to prevent the latching element from lifting off the locking contour, ensuring smooth operation and reduced noise by optimizing the relative speed, spring rate, and contour geometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If actuators work with higher shifting speeds in automated transmissions, then productivity is improved, but shift clicking noise increases
Solution Approach 1:
The patent applies parameter changes by optimizing the spring rate and latching contour geometry to prevent the latching element from lifting off during high-speed shifting operations. By carefully selecting the spring constant and designing the ramp angle and curvature radius of the latching contour, the system maintains reliable latching at higher shifting speeds while avoiding the impact loads that cause shift clicking noise.
Solution Approach 2:
The patent utilizes curvature by designing the latching contour with specific radius values (R1 and R2) at critical transition points. The rounded contours eliminate sharp edges that would cause impact loading of the latching element, thereby reducing shift clicking noise while maintaining functional performance during high-speed operation.
2Reliability
If the spring rate is increased to maintain pre-synchronizing force, then reliability is improved, but shift clicking noise increases
Solution Approach 1:
The patent resolves this contradiction by optimizing the spring rate parameter within a specific range that provides sufficient pre-synchronizing force without causing excessive impact loads. The patent specifies that the spring constant should be selected to maintain reliable engagement while preventing the latching element from lifting off during normal operation, thereby avoiding shift clicking.
Solution Approach 2:
The curved latching contour with optimized radius values softens the engagement of the latching element, reducing impact loads even when higher spring rates are used. The rounded transitions in the latching contour allow the ball to follow a smoother path, maintaining reliability while minimizing noise.
3Ease of operation
If the latching element is allowed to lift off the locking contour, then ease of operation is improved, but harmful noise is generated
Solution Approach 1:
The patent optimizes the ramp angle and curvature radius of the latching contour to enable smooth acceleration of the latching element during engagement. By carefully selecting these geometric parameters, the system allows the ball to follow the contour smoothly without sudden impacts, achieving ease of operation without generating harmful noise.
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 effectively minimizes shift clicking and associated noise during gear shifting, enhancing the quiet operation of transmission systems and maintaining a secure pre-synchronizing force, even at high relative speeds.
Implementation Method 1
a latching element such as a ball (42) being mounted on the first member (34) is pressed elastically against the second member (36) by means of a spring (44)
Data Source
Figure 1~2
AI summary
The assembly (40) has a guide sleeve (34) and a shift collar (36) movable opposite to each other, and a ball (42) supported at the guide sleeve. The ball is elastically pressed against the collar using a spring (44). A ratchet contour (46) is formed at the collar, and has a recess (60) in which the ball is engaged in a ratchet position, where the contour and the spring are designed for a preset relative speed of the sleeve and the collar such that the ball is not lifted from the contour during relative movement. A passage contour (52) is arranged between sitting and even contours (50, 54).