Transmission Shift Fork Orthogonal Protrusion Design
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Solution Overview
Problem
The existing transmission designs require additional features like corners or steps on contact faces to reduce interference during gear changes, which compromises the contact area and efficiency.
Innovation Solution
The transmission design ensures that the moving directions of the protrusions during the swing and rotation of the shift fork and shaft are orthogonal, allowing for proper contact without the need for narrowing or adding corners, enabling more compact placement and stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an inclined face or taper is added to the protrusion to reduce interference during gear change, then the interference between protrusions is reduced, but the contact face area decreases
Solution Approach 1:
The patent changes the spatial relationship between the two relative motion directions from parallel to approximately orthogonal. By making the moving direction during shift fork swing orthogonal to the moving direction during shaft twist, the patent eliminates the need for inclined faces or tapers, thereby maintaining full contact face area while still reducing interference between protrusions during gear changes.
2Object-affected harmful factors
If corners or steps are added to the contact face to reduce interference, then the interference between protrusions is reduced, but the contact face area and manufacturing simplicity decrease
Solution Approach 1:
The patent eliminates the need for corners or steps by changing the spatial orientation of motion directions to be approximately orthogonal. This allows the protrusions to maintain simple, smooth contact faces that are easy to manufacture, while the orthogonal arrangement inherently reduces interference during the combined gear change operation.
3Ease of operation
If the second shaft is positioned on the opposite side of the swinging center to provide adequate space, then the shaft can rotate freely, but the overall transmission size increases
Solution Approach 1:
The patent positions the second shaft on the same side of the swinging center as the shift fork, rather than on the opposite side. The approximately orthogonal arrangement of motion directions provides sufficient clearance for free rotation of the second shaft while maintaining a compact overall transmission size, as the orthogonal paths do not require additional space in the radial direction.
Data Source
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AI summary
A transmission according to an embodiment includes, for example, a shift fork swingably supported by a case to move a movable element in an axial direction in accordance with the motion of a second shaft to two shift positions; two first protrusions provided on one of the shift fork and the second shaft and spaced apart from each other in the axial direction; and a second protrusion provided on the other of the shift fork and the second shaft, and when the second shaft is in one of select positions, is positioned between the two first protrusions and overlaps with the first protrusions viewed from the axial direction. A protruding direction of the first protrusions and a protruding direction of the second protrusion are orthogonal to a swinging center of the shift fork when viewed in the axial direction.