Compact Parking Pawl and Cam Rod Layout for Drive Units
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional parking mechanisms require a large accommodation space due to the orthogonal arrangement of the parking rod and pawl, which hinders downsizing of the drive apparatus.
Innovation Solution
A parking mechanism design featuring a parking gear, a rotatable parking pawl, a cam rod, a cam, a U-shaped sleeve, and a pawl stopper, where the cam rod is inserted into the sleeve, allowing the cam to operate orthogonally to the parking pawl's rotation axis, reducing the need for axial space and enabling downsizing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the parking rod and parking pawl are arranged orthogonal to each other in conventional designs, then the parking mechanism can achieve reliable locking functionality, but the accommodation space in the housing becomes excessively large
Solution Approach 1:
The patent changes the spatial arrangement from a conventional orthogonal configuration to a coaxial configuration where the cam rod and parking pawl share the same rotation axis. This dimensional reorganization allows the mechanism to achieve the same locking function within a reduced radial space, effectively solving the contradiction between reliability and accommodation space by utilizing a different spatial dimension.
Solution Approach 2:
The cam rod is inserted into the hollow portion of the parking pawl, creating a nested structure where one component is placed inside another. This nesting arrangement eliminates the need for separate orthogonal mounting spaces, significantly reducing the overall accommodation volume while maintaining the functional integrity of both components for reliable locking operation.
2Volume of stationary object
If the cam rod is inserted into the hollow portion of the parking pawl, then the overall size of the parking mechanism is reduced, but the structural complexity increases
Solution Approach 1:
The parking pawl is designed with a hollow portion that serves multiple functions: it provides the structural body of the pawl, creates a nested receptacle for the cam rod, and maintains the necessary mechanical strength for locking. This multi-functionality approach reduces overall size while avoiding excessive structural complexity by making one component serve multiple purposes rather than adding separate components.
Solution Approach 2:
The patent merges the cam rod and parking pawl into a integrated nested structure where the cam rod is positioned within the hollow portion of the pawl. This merging eliminates the need for separate mounting structures and complex alignment mechanisms, reducing overall size while keeping the structural complexity manageable through a unified design approach.
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 effectively reduces the overall size of the parking mechanism while maintaining functionality, allowing for efficient operation and compact integration within the drive apparatus.
Implementation Method 1
a cam that is attached to the cam rod, is in contact with a cam contact portion of the parking pawl, and moves along the first direction with the operation of the cam rod to rotate the parking pawl around the first rotation axis and move the meshing portion toward the parking gear
Data Source
AI summary
A parking mechanism includes: a parking gear rotatable about a major axis with a wheel of a vehicle; a parking pawl rotatable about a first axis parallel to the major axis, and having a meshing portion facing a tooth portion of the parking gear; a cam rod extending and operating along a first direction orthogonal to the major axis; a cam attached to the cam rod, contacting the parking pawl, and movable along the first direction with the operation of the cam rod to rotate the parking pawl around the first axis and move the meshing portion toward the parking gear; a U-shaped sleeve open toward the parking pawl and supporting the cam; and a pawl stopper to contact and restrict movement of the parking pawl toward the cam rod. The cam rod is inserted into the sleeve. The pawl stopper is between the parking pawl and the cam rod.