Heavy-Vehicle Differential With Planetary Ratio Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle differentials lack versatility and improved functionality to effectively manage torque distribution across wheels, especially in varying grip conditions, leading to inefficiencies and potential skidding.
Innovation Solution
A differential group with a rotating structure and planetary gear system, incorporating a sleeve and actuator means to selectively engage different gear ratios, allowing for adaptable torque transmission between axle shafts and a drive source, enhancing versatility and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a differential is provided with a locking function to constrain axle shafts, then torque distribution is improved on low-grip surfaces, but the device complexity increases
Solution Approach 1:
The patent combines the differential function and locking function into a single integrated unit. The locking mechanism uses the existing differential components (satellites, carrier, axle shafts) to achieve both differential operation and locked operation, eliminating the need for separate locking devices and reducing overall system complexity despite adding functional capability.
Solution Approach 2:
The differential unit is designed to perform multiple functions: it operates as a standard differential during normal driving conditions and automatically locks when slip is detected. This multi-functionality is achieved through the interaction of satellites that can either rotate freely (differential mode) or lock the carrier to the housing (locked mode), providing both functions without requiring separate systems.
2Adaptability or versatility
If the differential allows different velocities to be delivered to wheels, then the vehicle can handle bends and different grips, but torque dispersion occurs on low-grip surfaces
Solution Approach 1:
The differential unit dynamically switches between two operational states based on driving conditions. During normal operation, the satellites rotate freely allowing differential speeds for cornering. When slip is detected, the centrifugal force or mechanical interaction causes the satellites to lock, converting the differential unit into a locked differential that distributes torque equally to both wheels, preventing torque dispersion on low-grip surfaces.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Differential group (1) for a heavy vehicle, comprising a casing (2) defining a space (3), a differential (8) and a transmission (9) housed inside the space (3), the differential (8) being configured to divide an input torque, transmitted from a drive source (7) to the differential group (1), between a pair of axle shafts (4, 5) of the vehicle, which are coaxial around an axis (A), the transmission (9) being operatively interposed between the drive source (7) and the differential (8) and comprising a rotating structure (16), which is carried, in a rotary free manner, by said casing (2) and a planetary (17), the rotating structure (16) being operatively interposed between the drive source (7) and the planetary (17) and defining a space (18) housing said planetary (17) and the differential (8), the solar (26) of the planetary (17) assuming a first operating condition, in which it is coped to the rotating structure (16) in a rotary manner, or a second operating condition, in which it is coupled to the casing (2) in a rotary manner.