Compact Transmission Clutch Axial Spring Nesting
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Solution Overview
Problem
In transmissions with planetary gear mechanisms, the increase in clutch size and complexity due to larger return springs required for faster clutch disconnection leads to delays and increased transmission size, particularly when space is limited between gear mechanisms.
Innovation Solution
The transmission design incorporates a first and second clutch with differing outer diameters, positioning the return spring axially with the first clutch and radially outside the second clutch, allowing for a compact arrangement that suppresses size increases and structural complexity, using a coil spring for high return force and a wave spring for efficient disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the return spring force is increased to enable faster clutch disconnection, then the clutch disconnection speed is improved, but the transmission size increases
Solution Approach 1:
The patent transitions from a conventional radial arrangement of the return spring to an axial arrangement. By positioning the return spring in the axial direction rather than the radial direction, the spring can be accommodated within the existing radial envelope of the transmission, eliminating the need to increase transmission size while still providing sufficient return force for rapid clutch disconnection.
Solution Approach 2:
The return spring is nested within the axial space already occupied by the clutch assembly and piston structure. The spring is positioned to act on the piston from the axial direction, utilizing the existing axial clearance and structural voids within the clutch assembly, thereby avoiding any increase in overall transmission dimensions.
2Volume of stationary object
If the return spring is arranged axially with the first clutch, then the transmission size is reduced, but the hydraulic fluid discharge delay increases
Solution Approach 1:
The patent changes the spatial arrangement of the return spring from radial to axial direction. This dimensional change allows the spring to directly act on the piston in the axial direction, creating a more efficient force transmission path that overcomes hydraulic pressure faster, thereby reducing discharge delay despite the compact axial arrangement.
Solution Approach 2:
The patent modifies the operational parameters of the clutch system by changing the direction and application point of the return spring force. The axial arrangement allows the spring to apply force more directly to the piston, changing the force vector and improving the rate at which the piston can overcome hydraulic pressure and discharge fluid, thus reducing time loss.
3Device complexity
If the return spring is arranged radially outside the clutch, then the clutch structure is simplified, but the transmission size increases
Solution Approach 1:
The patent resolves this contradiction by moving the return spring from the radial direction to the axial direction. This dimensional repositioning allows the spring to be integrated within the axial footprint of the clutch assembly rather than extending radially outward, maintaining structural simplicity while avoiding any increase in transmission size.
Solution Approach 2:
The axial arrangement of the return spring merges it with the existing clutch assembly structure. The spring is positioned to work in conjunction with the piston and clutch plates along the axial direction, integrating its function within the existing structural envelope rather than adding a separate radial component that would increase transmission dimensions.
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 enables swift clutch disconnection without size increments, maintains a compact transmission, and simplifies the structural connection, ensuring efficient operation and assembly.
Implementation Method 1
a return spring which presses the piston to separate from the clutch
Data Source
AI summary
A first clutch is configured to switch between connection and disconnection of a second carrier and a housing. The first clutch is arranged between a first planetary gear mechanism and a second planetary gear mechanism in the axial direction. A second clutch is arranged between the second planetary gear mechanism and the first planetary gear mechanism in the axial direction. The second clutch has an outer diameter which is smaller than an outer diameter of the first clutch. A first piston is configured so that, by applying pressure to the first clutch, the first clutch is connected. A return spring lines up with the first clutch in the axial direction and is arranged on the outside of the second clutch in the radial direction. The return spring presses the first piston to separate from the first clutch.