Planetary Gear Damper Layout for Low-Hysteresis Torque Damping
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Solution Overview
Problem
Conventional torque converters face challenges in improving vibration damping performance due to hysteresis issues in both torsional vibration dampers and rotary inertia mass dampers, which affect the overall vibration damping efficiency.
Innovation Solution
The damper device incorporates a configuration with an input element, an output element, an intermediate element, first and second elastic bodies, and a rotary inertia mass damper featuring a planetary gear system with a sun gear, carrier, and ring gear, where the intermediate element is composed of two plate members coupled by rivets, enhancing space for springs and reducing rigidity, thereby improving vibration damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lockup clutch is engaged and the cover plates are rotated relative to the sun gear, then the springs are deflected and the ring gear is rotated to generate inertia torque for vibration damping, but hysteresis occurs between the torque transmitted when input torque increases versus when it decreases due to friction between springs and cover plates
Solution Approach 1:
A carrier is introduced as an intermediary component between the cover plates and the ring gear. The carrier rotatably supports the pinion gears and transmits rotation to the ring gear, preventing direct contact and friction between the springs and cover plates, thereby eliminating the source of hysteresis loss while maintaining vibration damping functionality
Solution Approach 2:
The transmission path is segmented into distinct functional components: cover plates connected to springs, springs connected to sun gear, and a separate carrier-r_ring gear assembly. This segmentation isolates the friction-prone spring-cover plate interface from the inertia mass damper mechanism, allowing independent optimization of each subsystem
2Reliability
If the ring gear is supported by the two cover plates or carrier from both sides, then the mass body is constrained, but a difference in rotational speed between the ring gear and support members causes hysteresis in torque transmission
Solution Approach 1:
Pinion gears mounted on the carrier serve as intermediaries between the sun gear and ring gear. The carrier rotates at a different speed than the ring gear during operation, but this speed difference does not cause hysteresis because the pinion gears provide pure rolling contact without sliding friction, eliminating the energy loss mechanism
Solution Approach 2:
The direct mechanical support of the ring gear by cover plates is replaced with a planetary gear mechanism. Instead of direct contact between the ring gear and support members, the transmission is achieved through gear meshing between pinion gears and the ring gear, substituting a friction-based mechanical system with a gear-based system that eliminates sliding friction
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 hysteresis and enhances vibration damping performance by optimizing the interaction between the springs and the planetary gear system, leading to improved torque transmission and reduced vibration amplitude.
Implementation Method 1
a first elastic body disposed between the input element and the intermediate element, a second elastic body disposed between the intermediate element and the output element
Implementation Method 2
the springs that transmit the torque are pressed against the cover plates by a centrifugal force
Implementation Method 3
a frictional force occurs between the springs and the cover plates
Implementation Method 4
a planetary gear that includes a sun gear arranged to rotate integrally with one of the input element and the output element, a carrier that rotatably supports a plurality of pinion gears, and a ring gear that meshes with the plurality of pinion gears
Implementation Method 5
the ring gear as the mass body is rotated in accordance with relative rotation of the cover plates and the sun gear. This configuration causes an Inertia torque according to a difference in angular acceleration between the cover plates and the sun gear to be applied to the sun gear
Data Source
AI summary
A damper device includes an input element to which a torque from an engine is transmitted, an output element, an elastic body arranged to transmit a torque between the input element and the output element, and a rotary inertia mass damper that includes a planetary gear that includes a sun gear arranged to rotate integrally with one element of the input element and the output element, a carrier that rotatably supports a plurality of pinion gears and is arranged to rotate integrally with the other element of the input element and the output element, and a ring gear that meshes with the plurality of pinion gears and works as a mass body. The other element includes two plate members that are opposed to each other and coupled with each other by means of a plurality of rivets disposed between the pinion gears.