Shaft Drive Power Unit Cam Damper Mechanism
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Solution Overview
Problem
In shaft drive type vehicle power units, it is challenging to maintain uniform preloading of the damper spring and adjust the mesh amount of bevel gears without affecting each other, especially when using a cam damper mechanism and bevel gears on an extended shaft.
Innovation Solution
The power unit design includes a cam damper mechanism with a cam member unrotatably mounted on a bevel gear and a damper spring supported by a flange portion, allowing for independent adjustment of the bevel gear mesh without affecting the damper spring preloading, and features a collar member with cylindrical portions to enhance bearing support and reduce friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a shim is provided between the bevel gear case and bearing to adjust bevel gear mesh, then the bevel gear meshing state can be adjusted, but the damper spring preload cannot be confirmed and changes with shim thickness
Solution Approach 1:
The invention separates the adjustment functions by providing a dedicated adjustment member (adjusting screw) that is distinct from the shim. This allows independent adjustment of bevel gear mesh without affecting damper spring preload, resolving the coupling between the two functions that caused the technical contradiction.
Solution Approach 2:
The invention introduces an adjustment member (adjusting screw) as an intermediary element between the bevel gear case and bearing. This intermediary allows precise control of bevel gear mesh while the damper spring preload is controlled separately through the damper spring support structure, eliminating the interference between the two adjustment functions.
2Ease of manufacture
If the damper spring is preloaded after the bevel gear cover is attached, then the cam damper mechanism can be assembled, but it is difficult to confirm preload and it changes according to shim thickness
Solution Approach 1:
The invention enables preliminary setting of the damper spring preload during the assembly process by providing a dedicated damper spring support structure with adjustable preload. This allows the preload to be set and confirmed before final assembly, improving measurement precision while maintaining ease of manufacture.
3Device complexity
If both shim and damper spring are fastened and compressed together, then the structure is compact, but there is difficulty in confirming damper spring preload and it changes with shim thickness
Solution Approach 1:
The invention segments the load-bearing functions by providing separate support structures: the shim supports the bevel gear meshing loads while the damper spring support structure independently supports the damper spring preload. This segmentation maintains structural compactness while ensuring preload stability by eliminating the coupling between shim thickness variations and damper spring preload.
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 design ensures uniform damper spring preloading and facilitates easy adjustment of bevel gear mesh, reduces frictional resistance, and supports the extended shaft with a capacious bearing without increasing device size, thereby improving operational efficiency and cost-effectiveness.
Implementation Method 1
a damper spring which pressure-welds the lifter member and the cam member, the cam member of the cam damper mechanism is reciprocally unrotatably provided on the bevel gear
Implementation Method 2
an outer end portion of the extended shaft is rotatably supported on a bevel gear via a bearing
Data Source
AI summary
A power unit includes a cam damper mechanism having a cam member reciprocally and unrotatably provided on one of a pair of bevel gears, and rotatably provided on an extended shaft; a lifter member slidably and unrotatably provided on the extended shaft in an axial direction; a damper spring configured such that one end portion thereof is supported on a first flange portion of the extended shaft, and the other end portion thereof biases the lifter member toward the cam member in an axial direction by abutting on the lifter member, and the biasing force is supported by the one bevel gear. The extended shaft has the one of the bevel gears and the cam damper mechanism between the first flange portion and a first bearing, and is accommodated in the bevel gear case so as to be fixed to a bevel gear holder along with the first bearing.