Conical Clutch Actuator for Transfer Case Torque Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing torque transfer mechanisms in automotive transfer cases, particularly those using friction engagement devices, require complex machining operations for ball ramp actuators, which are costly and time-consuming to produce.
Innovation Solution
A novel actuator comprising beveled wedge washers, a bearing race with conical bearing rollers, and an actuator plate that rotates to move the rollers radially inwardly, causing axial compression of a disk pack for torque transmission, simplifying construction and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ball ramp actuators are used for clutch pack compression, then reliable torque transmission is achieved, but manufacturing complexity and cost increase due to complex machining operations
Solution Approach 1:
The actuator is divided into separate functional components: a clutch actuator arm, a bearing assembly with conical rollers, and a bearing race. This segmentation allows each part to be manufactured independently using simpler processes, eliminating the need for complex integrated ball ramp machining while maintaining the torque transmission function.
Solution Approach 2:
Instead of using ball ramps that require precise angular machining surfaces, the invention inverts the approach by using conical bearing rollers within a bearing race. The conical geometry naturally provides the mechanical advantage needed for clutch engagement without requiring complex ramp angles, simplifying the manufacturing process.
2Force
If ball ramp actuators are used for clutch engagement, then effective clamping force is generated, but production time increases due to time-consuming machining operations
Solution Approach 1:
The invention changes the geometric parameters from ball ramp angles to conical bearing roller dimensions. The conical shape with its natural taper provides the necessary mechanical leverage for generating clamping force, and these parameters can be more efficiently produced through standard bearing manufacturing processes rather than time-consuming custom ramp machining.
Solution Approach 2:
The complex ball ramp mechanical system is replaced with a bearing-based mechanical system. The conical bearing rollers provide the same force multiplication function through rolling contact mechanics, which can be manufactured more quickly using established bearing production techniques.
3Power
If conventional clutch actuators are used, then torque transfer is achieved, but device complexity increases with multiple components and maintenance requirements
Solution Approach 1:
The invention merges the actuator arm, bearing support, and clutch engagement mechanisms into an integrated assembly where the bearing race and conical rollers serve dual functions as both support structures and force transmission elements. This reduces the number of separate components compared to traditional ball ramp actuators while maintaining full torque transfer capability.
Solution Approach 2:
The conical bearing rollers serve multiple functions: they provide rotational support, transmit mechanical force, and enable the clutch engagement/disengagement action. This multi-functionality reduces overall device complexity compared to systems requiring separate components for each function.
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 enables efficient and selective torque transmission through a friction engagement device, reducing production complexity and maintenance needs while allowing for controlled torque distribution between front and rear drive axles.
Implementation Method 1
a bearing race between the washers supporting conical bearing rollers in a generally radial orientation
Implementation Method 2
an actuator plate that is rotated, relative to the bearing race, to move the conical bearing rollers radially inwardly to force the washers to move apart axially
Implementation Method 3
The actuator comprises a pair of beveled wedge washers, a bearing race between the washers supporting conical bearing rollers
Implementation Method 4
disk packs that transmit torque when subjected to axial compression and do not transmit torque when uncompressed
Data Source
AI summary
An actuator for selectively causing axial compression of friction elements in a clutch is disclosed. The actuator comprises a pair of beveled wedge washers and a bearing race supported between the washers. The race supports conical bearing rollers in a generally radial orientation. An actuator plate is mounted for rotation relative to the bearing race and includes bearing ramp surfaces that are operable to move the conical bearing rollers radially inwardly thereby forcing the washers to move apart axially and to thereby cause compression of and torque transfer through the friction elements. A clutch including the actuator is well suited for inclusion in a transfer case.