Hybrid Powertrain Speed Synchronization Without a Friction Clutch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional clutch mechanisms in vehicles with hybrid propulsion systems lead to increased fuel consumption, wear, and weight, along with significant friction losses and space requirements.
Innovation Solution
A method that controls the electric machine's torque and the combustion engine's rotational speed to synchronize the rotational speeds of components in a planetary gear system, allowing for seamless interlocking without torque interruption, thereby eliminating the need for a conventional clutch mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional clutch mechanism is used to disconnect the input shaft of the gearbox during gearchanging, then the gearchanging process can be performed, but this results in heating of the clutch discs, increased fuel consumption, and wear of the clutch discs
Solution Approach 1:
The invention extracts and eliminates the conventional clutch mechanism from the drivetrain by using a planetary gear system where the planet carrier can be selectively locked or unlocked. This allows gearchanging to occur without a separate clutch disconnecting the engine from the gearbox, thereby eliminating clutch disc heating and wear while reducing fuel consumption.
Solution Approach 2:
The invention merges the gearchanging function with the planetary gear system's locking mechanism. The lockable planet carrier serves dual purposes: enabling gear changes and eliminating the need for a separate clutch mechanism, thus combining multiple functions into a single integrated system that improves energy efficiency.
2Ease of operation
If a conventional clutch mechanism is used for starting the vehicle, then the vehicle can be started, but considerable losses are caused and the clutch mechanism is heavy and costly
Solution Approach 1:
The invention extracts the clutch mechanism entirely from the vehicle starting system. The planetary gear system with its lockable planet carrier provides the necessary torque multiplication and engagement control for vehicle starting without requiring a separate clutch assembly, thereby eliminating the weight and cost of the clutch mechanism.
Solution Approach 2:
The planetary gear system serves multiple functions including gear changing, vehicle starting, and torque management. The lockable planet carrier acts as a universal engagement mechanism that replaces the clutch's starting function while also providing gear ratio changes, eliminating the need for dedicated clutch components.
3Ease of operation
If a conventional clutch mechanism is used, then disconnection during gearchanging is achieved, but friction losses are created and a large space is required in the vehicle
Solution Approach 1:
The invention merges the gearchanging function with the planetary gear system's inherent locking capability. The lockable planet carrier integrates the disconnection/engagement function directly into the gear train, eliminating the need for a separate clutch assembly and its associated hydraulic systems, thereby reducing space requirements while maintaining full gearchanging capability.
Solution Approach 2:
The planetary gear system nests the locking mechanism within the existing gear train structure. The lockable planet carrier is integrated into the compact planetary gear arrangement, allowing the engagement and disengagement functions to be performed within the same spatial envelope as the gearbox itself, eliminating additional space requirements for separate clutch components.
4Force
If a friction clutch is used for torque transmission, then torque can be transmitted during gearchanging, but friction losses are created and wear occurs
Solution Approach 1:
The invention replaces the friction-based clutch torque transmission mechanism with a positive engagement locking system. The lockable planet carrier provides direct mechanical locking of the planetary gear components, eliminating friction-based torque transmission and its associated energy losses and wear while maintaining full torque capability during gearchanging operations.
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 approach enhances energy efficiency, reduces weight and cost, and maintains standardized interfaces, while allowing for higher brake torque and compact design, thus improving the overall performance and efficiency of hybrid vehicles.
Implementation Method 1
When the vehicle is braked the electric machine generates electrical energy which may be stored
Implementation Method 2
the output shaft of the combustion engine, the rotor of the electric machine and the input shaft of the gearbox are interconnected by a planetary gear
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method for accelerating a vehicle driving forward, in which the vehicle has a propulsion system comprising a combustion engine with an output shaft (2a), a gearbox (3) with an input shaft (3a), an electric machine (9) comprising a stator and a rotor, and a planetary gear comprising a sun gear (10), a ring gear (11) and a planet wheel carrier (12). When accelerating the vehicle the torque of the electric machine is controlled and the rotational speed of the combustion engine is controlled until the members of the planetary gear have the same rotational speed and may be interlocked.