Vehicle Transmission Reverse Dog Clutch Low-Speed Engagement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing vehicle transmission system experiences significant rotational speed differences between the main shaft-side sprocket and the main shaft-outer shaft during low-speed traveling modes, leading to noise and shock issues when engaging these components.
Innovation Solution
The system incorporates a reverse dog clutch that engages with the main shaft-side sprocket, allowing for a smaller rotational speed difference and reducing noise and shock by disconnecting the first and second clutches when shifting from first gear to neutral, and using a drive gear for second gear to achieve smooth low-speed travel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the main shaft-side sprocket and main shaft-outer shaft are engaged in low-speed traveling mode, then the vehicle can move forward or rearward with simple controller operation, but the large rotational speed difference (1500 rpm) between the sprocket and shaft causes significant shock and noise
Solution Approach 1:
A dog clutch is introduced as an intermediary mechanism between the main shaft-side sprocket and the main shaft-outer shaft. This dog clutch can selectively engage or disengage the connection, allowing the rotational speed difference to be managed during engagement transitions. The dog clutch acts as a mediator that controls the power transmission path, enabling smooth engagement by controlling when the sprocket and shaft are connected, thereby reducing shock and noise while maintaining ease of operation.
2Ease of operation
If the clutches are disconnected in neutral state, then the vehicle transmission can be shifted, but residual oil in the clutches generates spurious clutch capacity causing slight rotation of the main shaft-inner shaft and main shaft-outer shaft
Solution Approach 1:
The harmful effect of residual oil generating spurious clutch capacity is isolated and managed by separating the clutch disengagement function from the neutral state requirement. The system extracts the problematic residual oil effect and contains it within the clutch assembly, while the neutral state is achieved through the dog clutch mechanism that physically disconnects the power transmission path. This allows gear shifting to proceed reliably without the instability caused by residual oil capacity.
3Speed
If the main shaft-inner shaft and main shaft-outer shaft rotate at 1000 rpm with gear ratio 2 and sprocket ratio 1, then the main shaft-side sprocket rotates at -500 rpm, but this creates a 1500 rpm rotational speed difference that enlarges engagement shock
Solution Approach 1:
The system employs dynamic engagement control through the dog clutch mechanism, which can engage or disengage based on operational requirements. Rather than maintaining a fixed connection that would always experience the 1500 rpm speed difference, the dog clutch dynamically manages the connection state. During engagement transitions, the dog clutch allows the rotational speeds to equalize before establishing full power transmission, thereby reducing engagement shock while still enabling the required speed ratios during active operation.
Data Source
AI summary
A transmission that reduces the difference of rotational speed when engaging a main shaft-side sprocket and a main shaft-outer shaft, in a low-speed traveling mode. When shifting from first gear to neutral in the transmission, a dog on a drive gear is engaged with a dog hole in a main shaft-side sprocket, engagement between a dog on a driven gear for first gear and a dog hole in a driven gear is released, and then a first clutch and a second clutch are disconnected with the drive gear and the main shaft-side sprocket being engaged.