CVT Drive Pulley Cam Coupling for Low-Noise Torque Response
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Solution Overview
Problem
Traditional CVT transmission systems in motorcycles often suffer from significant noise issues when adapting to varying torque demands, limiting their ability to quickly respond to driver requests for more or less torque.
Innovation Solution
A CVT transmission device featuring a drive pulley with a movable and fixed bushing system, utilizing a cam profile with a shape coupling mechanism that minimizes noise by ensuring precise contact between the bushings, allowing for smooth torque adjustments and reduced noise through the absence of lubrication and oil seals, enabling more sporty behavior and efficient gear shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional CVT transmission systems are used, then the gear ratio can be varied continuously, but significant noise occurs when adapting to varying torque demands
Solution Approach 1:
The patent applies dynamics by making the bushing configuration adjustable rather than fixed. The transmission system can dynamically switch between a movable bushing configuration (for sporty behavior and quick torque adaptation) and a fixed bushing configuration (for reduced noise and comfort). This dynamic reconfiguration allows the system to adapt its characteristics based on operating conditions, resolving the contradiction between torque adaptation capability and noise generation.
Solution Approach 2:
The patent changes the structural parameter of the bushing system from fixed to adjustable/movable. By varying the position and configuration of the bushings, the system can modify its mechanical characteristics to either prioritize noise reduction or prioritize responsive torque adaptation, thereby resolving the technical contradiction between these two opposing requirements.
2Speed
If the bushing configuration is made movable for sporty behavior, then torque adaptation becomes more responsive, but noise increases
Solution Approach 1:
The patent implements a dynamic bushing configuration that can switch between movable and fixed states. When sporty behavior is desired, the movable configuration enables faster torque response. When noise reduction is prioritized, the fixed configuration suppresses noise. This dynamic capability allows the system to optimize performance based on real-time requirements.
Solution Approach 2:
The transmission system can periodically or conditionally switch between different bushing configurations based on operating conditions. This periodic reconfiguration allows the system to alternate between high-response modes (movable bushings) and low-noise modes (fixed bushings), effectively managing the trade-off between torque response speed and noise generation.
3Object-generated harmful factors
If a fixed bushing system is used, then noise is reduced, but the ability to quickly adapt to torque demands is limited
Solution Approach 1:
Rather than using a purely fixed bushing system, the patent employs an adjustable system that can operate in both fixed and movable configurations. The fixed configuration provides noise reduction, while the movable configuration enables rapid torque adaptation. This dynamic dual-mode system resolves the contradiction by allowing the user to select the appropriate configuration for each operating condition.
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 significantly reduces noise and enhances the CVT's ability to adapt to torque demands, providing a more responsive and reliable transmission system with improved operating reliability and compact design.
Implementation Method 1
A CVT transmission device featuring a drive pulley with a movable and fixed bushing system, utilizing a cam profile with a shape coupling mechanism
Implementation Method 2
The rollers create centrifugal masses which push the first half-pulley 8, and in particular the movable bushing 9, towards the second half-pulley 10 as the number of engine revolutions increases.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A continuous variation transmission device (1) for a motorcycle with two/three/four- wheels comprises a drive pulley (4) provided with a movable bushing (9), a fixed bushing (11) and a cam system (95,111;97,113) between the fixed bushing (11) and the movable bushing (9). The cam system has a driven cam portion (95) of the movable bushing (9) and a drive cam portion (111) of the fixed bushing (11). The driven cam portion (95) comprises at least one recess (99) and the drive cam portion (111) comprises at least one tooth (115) or vice versa. The recess (99) and the tooth (115) have respective sides (99a, 99b; 115a, 115b) which form a shape coupling with each other to guide the relative movement between said movable bushing (9) and said fixed bushing (11).