Cycloidal Differential with Eccentric Gears for Slip Limiting
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Solution Overview
Problem
Conventional limited slip differentials face challenges in efficiently distributing torque between front and rear wheels, have high manufacturing costs, and are inconvenient for slip limiting, especially when used as central differentials, due to their mechanical or electrically controlled mechanisms.
Innovation Solution
A cycloidal differential design featuring a planet carrier with A-type and B-type planet gears, oscillating gears, and output gears with 180-degree phase difference eccentric shafts, which form internal cycloidal gear pairs, increasing friction and reducing radial loads, allowing for adjustable torque distribution through gear ratios and friction plates, enhancing slip limiting capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional limited slip differentials use mechanical worm and gear for locking, then locking function is achieved, but manufacturing cost increases
Solution Approach 1:
The patent replaces the conventional mechanical worm and gear locking system with a cycloidal gear mechanism. The cycloidal differential uses a cycloidal pinwheel gear that automatically locks and unlocks based on torque differential, eliminating the need for separate locking mechanisms while maintaining reliable slip limitation functionality.
Solution Approach 2:
The invention changes the fundamental gear mechanism from conventional spiral/bevel gears to cycloidal gears. By altering the gear tooth geometry to cycloidal profiles and using eccentric shafts, the system achieves automatic locking through geometric constraints rather than mechanical locking elements, reducing manufacturing complexity and cost.
2Reliability
If conventional limited slip differentials use electrically controlled multi-plate clutch for locking, then locking function is achieved, but response speed decreases
Solution Approach 1:
The patent replaces electrically controlled multi-plate clutch systems with a purely mechanical cycloidal gear mechanism. The cycloidal pinwheel automatically engages and disengages through mechanical torque differential, providing instantaneous response without electrical delays or complex control systems.
Solution Approach 2:
The cycloidal differential is self-regulating through its geometric design. When torque differential exceeds a threshold, the cycloidal teeth naturally lock through geometric constraints, and automatically unlock when torque equalizes, without requiring external control signals or active components.
3Power
If conventional differentials use helical gear or crown gear structure, then power transmission is achieved, but slip limiting capability is insufficient
Solution Approach 1:
The patent fundamentally changes the gear type from helical or crown gears to cycloidal gears with eccentric shafts. This geometric transformation enables the mechanism to automatically limit slip by converting excessive torque differential into mechanical locking through the cycloidal tooth engagement, while maintaining efficient power transmission during normal 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
The cycloidal differential effectively reduces rotation inertia, improves transmission efficiency, and enhances slip limiting by balancing radial pressures and increasing friction, while allowing for more precise torque distribution without increasing manufacturing complexity or cost.
Implementation Method 1
a cycloidal gear 9, with several pin holes, engaging with a pin or needle gear sleeve 3 is mounted on an outer side of each eccentric bearing 8
Implementation Method 2
allowing for adjustable torque distribution through gear ratios and friction plates, enhancing slip limiting capabilities
Implementation Method 3
A-type and B-type planet gears, oscillating gears, and output gears with 180-degree phase difference eccentric shafts, which form internal cycloidal gear pairs, increasing friction and reducing radial loads
Data Source
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AI summary
A differential is provided, comprising a housing, an internal gear pair consisting of an oscillating gear A and an output gear A, an internal gear pair consisting of an oscillating gear B and an output gear B, at least two A-type intermediate gears, and at least two B-type intermediate gears. Each A-type intermediate gear is radially fixed to the housing, and an axis of rotation of each A-type intermediate gear is parallel to an axis of rotation of the housing. Each A-type intermediate gear is meshed with at least one B-type intermediate gear, and the gear ratio of each gear pair consisting of an A-type intermediate gear and a B-type intermediate gear is the same. Each A-type intermediate gear is provided with an eccentric shaft having an axis parallel to its axis of rotation, and the eccentric shaft on each A-type intermediate gear has the same distance from the axis of rotation of the gear. The eccentric shafts on all A-type intermediate gears are the same in phase, and the eccentric shaft on each A-type intermediate gear is radially fixed to the oscillating gear A, respectively. The output gear is coaxial with the axis of rotation of the housing.