Self-Ejecting Claw Clutch Gearbox Torque Management
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Solution Overview
Problem
Conventional gearboxes experience torque breakdown and shock during gear changes due to instantaneous equalization of rotational speeds, leading to discomfort and the risk of kinematic blocking, especially with minimal re-coupling play.
Innovation Solution
The implementation of self-ejecting claws with a friction member on the final or intermediate gear ratio to divert torque and equalize rotational speeds, allowing smooth gear changes by automatically disengaging the previous gear and engaging the next while maintaining torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional claws are used for gear changing, then the gearbox structure remains simple, but torque breakdown and shock occur during gear changes due to instantaneous equalization of rotational speeds
Solution Approach 1:
A friction member is introduced as an intermediary element between the driving and driven shafts. This friction member temporarily transmits torque during gear changes, acting as a mediator that smooths the transition between gears by allowing gradual equalization of rotational speeds rather than instantaneous connection, thereby eliminating shock while maintaining structural simplicity
Solution Approach 2:
The friction member is activated before the actual gear engagement occurs to pre-equalize the rotational speeds of the driving and driven shafts. This preliminary action prepares the system for smooth gear transition by reducing speed differences in advance, preventing shock during the subsequent claw engagement
2Reliability
If synchronizers are used to equalize rotational speeds before dog clutch engagement, then shock is reduced, but torque transmission is interrupted during gear changes
Solution Approach 1:
The friction member serves as a continuous torque transmission path during gear changes. Unlike synchronizers that interrupt torque flow, the friction member maintains continuous torque transmission while equalizing speeds, ensuring both smoothness and continuity of power delivery throughout the gear transition process
Solution Approach 2:
The friction member ensures continuous torque transmission from the driving shaft to the driven shaft throughout the entire gear change process. The useful action of torque transmission never interrupts, as the friction member maintains the power flow while the dog clutch transitions between gears, eliminating the productivity loss associated with synchronizer operation
3Manufacturing precision
If minimal re-coupling play is used in engaged gear, then precision is improved, but the risk of kinematic blocking increases during gear changes
Solution Approach 1:
The friction member is activated in advance to equalize rotational speeds before the dog clutch engagement. This preliminary speed equalization eliminates the speed differential that would otherwise cause kinematic blocking when minimal re-coupling play is present, allowing precise engagement without the risk of blocking
Solution Approach 2:
The friction member provides a cushioning effect by gradually equalizing speeds before engagement. This beforehand cushioning prevents the sudden speed differential that would cause blocking in precision gear systems with minimal re-coupling play, protecting the precise mechanism from harmful shocks
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 solution eliminates torque breakdown and shock during gear changes, ensures smooth torque transmission, and reduces the risk of kinematic blocking, enhancing the overall gear shifting experience by using self-ejecting profiles and a friction member to manage rotational speed differences.
Implementation Method 1
a friction member (31) mounted on the highest gear, here the 6th gear ratio (6), to divert torque and equalize rotational speeds
Data Source
Figure 1~3
Figure 2
Figure 4
AI summary
The gearbox (4) has a shaft (7) connected to a heat engine (2), and another shaft (8) connected to wheels (5) of a vehicle. A gear comprises a set of idler gears (15-17, 23, 24) mounted on one of the shafts. A friction unit (31) is associated with a transmission ratio, and frictionally transmits torque in a temporary manner during changing of the gear ratio via the transmission ratio. A set of sleeve claws (27 - 29) and the idler gear are automatically ejected, where the automatically ejected claws eject a preceding ratio, when a new ratio is engaged without breaking torque. Independent claims are also included for the following: (1) a method for changing a gear ratio rising with positive torque for passing a manually controlled six-speed gearbox from initial ratio to final ratio (2) a method for changing the gear ratio decreasing with positive torque for passing the manually controlled six-speed gearbox from initial ratio to final ratio (3) a method for changing the gear ratio rising/decreasing with negative torque for passing a manually controlled six-speed gearbox from initial ratio to final ratio.