Planetary Gearbox Coupling Sleeve Layout for Faster Vehicle Shifting
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Solution Overview
Problem
Existing gearboxes in vehicles, particularly heavier vehicles, face challenges with long shifting times, high wear, and stress on components due to the traditional design of planetary gears, which also lead to increased weight and noise issues with reverse gears.
Innovation Solution
A gearbox design featuring short axial stroke coupling sleeves that quickly switch between gear positions, reducing the velocity and power needed for shifting, thereby minimizing wear and stress on components, and incorporating a range gearbox that allows for efficient torque transmission through the ring gear, eliminating the need for a traditional reverse gear in the main gearbox.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If traditional planetary gear design with long axial stroke coupling sleeves is used, then gear engagement is achieved, but shifting time increases and component wear increases
Solution Approach 1:
The patent applies parameter changes by reducing the axial stroke length of the coupling sleeves from traditional long stroke to short stroke design. This parameter modification enables faster shifting operations while maintaining proper gear engagement, directly resolving the contradiction between shifting time and operational feasibility.
Solution Approach 2:
The patent segments the gear engagement process into distinct phases: disengagement of the first coupling sleeve, engagement of the second coupling sleeve, and synchronized shifting. This segmentation allows each component to perform its function independently and efficiently, reducing overall shifting time while maintaining proper engagement sequences.
2Reliability
If traditional planetary gear design with long axial stroke coupling sleeves is used, then gear engagement is achieved, but wear and stress on components increases
Solution Approach 1:
The patent modifies the axial stroke parameter of the coupling sleeves to be shorter, which directly reduces the axial force and stress applied to the components during engagement. This parameter change decreases wear on the coupling sleeves and related components, extending their service life while maintaining engagement functionality.
Solution Approach 2:
The patent implements preliminary disengagement of the first coupling sleeve before engagement of the second coupling sleeve. This preliminary action sequence reduces the simultaneous stress and wear on multiple components, thereby improving overall component reliability and service life.
3Object-generated harmful factors
If helical teeth are used in planetary gears, then sound from planetary gear is reduced, but reaction force in the direction of rotation axis increases
Solution Approach 1:
The patent utilizes the reaction force generated by helical teeth, which normally acts as a harmful axial load, and converts it into a beneficial synchronizing force. The axial reaction force helps to synchronize the rotational speeds of engaging gears during shifting operations, transforming a potential harm into a useful function that aids the shifting process.
Solution Approach 2:
The patent introduces the axial reaction force from helical teeth as an intermediary mechanism that facilitates synchronization during gear engagement. This reaction force acts as a mediator between the driving and driven gears, enabling smooth speed synchronization without requiring additional complex synchronization mechanisms.
4Adaptability or versatility
If reverse gear wheel is added to main gearbox, then reverse gear function is achieved, but weight of vehicle increases
Solution Approach 1:
The patent implements multi-functionality by enabling the planetary gear mechanism to perform both forward gear operation and reverse gear function. Through controlled engagement and disengagement of coupling sleeves and reversal of torque direction, the same planetary gear set provides both forward and reverse motion, eliminating the need for a separate reverse gear wheel and reducing vehicle weight.
Solution Approach 2:
The patent merges the reverse gear function with the existing planetary gear mechanism. By combining reverse gear capability into the planetary gear system through intelligent control of coupling sleeves and torque flow, the design eliminates redundant components and reduces overall vehicle weight while maintaining adaptability for both forward and reverse operation.
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 design results in faster shifting, reduced wear and stress on gearbox components, improved driving characteristics, increased service life, and enhanced reliability of the vehicle's transmission system.
Implementation Method 1
The coupling sleeves are axially displaceable to selectively engage and disengage the sun gear, planet gear carrier and ring gear with each other and/or with the input shaft and output shaft
Data Source
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AI summary
The invention relates to a gearbox (2) for a vehicle (1), the gearbox (2) comprising: a planetary gear (14) with a ring gear (22), a sun gear (18) and a planet gear carrier (20), on which at least one planet gear (24) is rotatably mounted, which ring gear (22) and sun gear (18) are configured to engage with the at least one planet gear (24); a gearbox housing (12) surrounding the planetary gear (14); an input shaft (16) and an output shaft (28) for transfer of torque to and from the gearbox (2); a first axially movable coupling sleeve (42) for selectively engaging and disengaging the planetary gear (14) with/from the gearbox housing (12) and for selectively engaging and disengaging the ring gear (22), the sun gear (18) and the planet gear carrier (20) with/from each other; and a second axially movable coupling sleeve (43) for selectively engaging and disengaging the output shaft (28) with/from the ring gear (22) and with/from the planet gear carrier (20). Wherein the first axially movable coupling sleeve (42), in a first gear position, is configured to engage the ring gear (22) with the gearbox housing (12), and in a second gear position is configured to engage the sun gear (18) with the ring gear (22); the second axially movable coupling sleeve (43), in the first gear position, is configured to engage the planet gear carrier (20) with the output shaft (28), and in the second gear position is configured to engage the ring gear (22) with the output shaft (28); and wherein the second axially movable coupling sleeve (43), in a neutral position, is configured to be positioned in an intermediate axial position between the first and second gear positions. The invention also relates to a vehicle (1), wherein the vehicle (1) comprises such a gearbox (2).