Vehicle Drive Apparatus Slip Control Vibration Suppression
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Solution Overview
Problem
Conventional vehicle drive devices with torsional vibration reduction devices disposed in series with a lockup clutch experience reduced vibration reduction effects, especially with engines having large torque variations, leading to discomfort and inhibited fuel efficiency due to interrupted vibration transmission.
Innovation Solution
A vehicle drive device configuration where the torsional vibration reduction device is positioned in the power transmission path between the engine and fluid power transmission device, with specific differential rotation speed settings during slip engagement to enhance vibration suppression and durability of the clutch's friction material, including setting a minimum differential rotation speed greater than zero between input and output members and less than zero between inertial bodies, and limiting differential rotation to 1/2 rotations per second.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the torsional vibration reduction device is disposed in series with the lockup clutch (in parallel with the torque converter), then the device complexity is reduced, but the vibration reduction effect deteriorates because vibration input is interrupted by the clutch
Solution Approach 1:
The patent introduces a vibration transmission mechanism as an intermediary between the clutch and the torsional vibration reduction device. This intermediary component allows vibration signals to pass through the clutch assembly to reach the vibration reduction device, solving the problem of vibration interruption while maintaining the simplified series configuration.
Solution Approach 2:
The patent segments the clutch assembly into multiple functional components, including a clutch hub, friction plates, and a vibration transmission mechanism. This segmentation allows the vibration transmission function to be separated from the clutch engagement function, enabling vibration to be transmitted to the reduction device while the clutch performs its primary function.
2Use of energy by moving object
If slip control of the lockup clutch is provided to improve fuel efficiency, then the fuel efficiency is improved, but the vibration reduction effect deteriorates as vibration is not transmitted to the torsional vibration reduction device
Solution Approach 1:
The vibration transmission mechanism serves as a mediator that maintains vibration signal transmission during clutch slip control operations. This allows the clutch to perform slip control for fuel efficiency improvement while simultaneously allowing vibration signals to reach the reduction device for vibration suppression.
Solution Approach 2:
The patent ensures continuous vibration transmission through the clutch assembly by designing the vibration transmission mechanism to operate effectively during all clutch states, including slip control. This maintains the continuity of the vibration reduction function while the clutch performs its useful action of slip control for fuel efficiency.
3Object-affected harmful factors
If the torsional vibration reduction device is disposed in series with the fluid power transmission device, then the vibration reduction effect is improved, but the device complexity increases
Solution Approach 1:
The patent merges the vibration transmission function with the existing clutch assembly structure. The vibration transmission mechanism is integrated into the clutch hub and friction plate arrangement, combining the vibration reduction function with the clutch function in a unified structure, thereby reducing overall device complexity.
Solution Approach 2:
The clutch assembly is designed to perform multiple functions: primary clutch engagement/disengagement, slip control for fuel efficiency, and vibration transmission to the reduction device. This multi-functionality eliminates the need for separate dedicated vibration transmission components, reducing device complexity.
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 configuration effectively reduces torsional vibration input to the clutch, improves friction material durability, and achieves simultaneous slip control and vibration suppression, resulting in improved fuel efficiency and vibration reduction compared to conventional setups.
Implementation Method 1
a torsional vibration reduction device disposed in a power transmission path between the engine and the fluid power transmission device
Implementation Method 2
a minimum value set less than zero for a differential rotation speed acquired by subtracting the rotation speed of the output side member from a rotation speed of an input side inertial body in the torsional vibration reduction device
Implementation Method 3
a clutch disposed between an input side member and an output side member in the fluid power transmission device
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
Providing a vehicle drive device realizing preferred fuel efficiency while allowing a torsional vibration reduction device to produce a vibration suppressing effect during slip control of a clutch included in a fluid power transmission device. During slip control when a clutch 18 is put into slip engagement, a minimum value of differential rotation speed of the clutch 18 is set equal to or greater than zero while a minimum value of differential rotation speed is set less than zero between a first inertial body 100 acting as an input side inertial body in a damper mechanism 84 and a turbine impeller 14t and, therefore, torsional vibration input to the clutch 18 can be reduced by the damper mechanism 84 while a durability of a friction material 78 in the clutch 18 is improved, and the slip control by the clutch 18 and vibration suppression by the damper mechanism 84 can be achieved at the same time.