Dynamic Damper Planetary Gear Device for Wide Gear Ratio Range
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Solution Overview
Problem
Conventional dynamic dampers with a planetary gear device have limitations in gear ratio range and radial size, leading to increased energy loss and interference issues due to the restricted number of rotating elements, which affects the vehicle's acceleration performance and space efficiency.
Innovation Solution
The dynamic damper employs a planetary gear device with double pinion planetary gears and a carrier, allowing for a maximum of five rotating elements, including sun gears and ring gears, to provide a wide range of gear ratios and increased freedom in arrangement, optimizing the reduction of rotational fluctuations and radial size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a normal type of planetary gear device with three rotating elements is employed, then the structure is simple and easy to manufacture, but the gear ratio range is limited and the radial size is increased
Solution Approach 1:
The planetary gear device is segmented into multiple independent rotating elements (sun gear, ring gear, carrier, and additional rotating element) that can be selectively connected to input and output shafts. This segmentation allows for multiple gear ratio configurations by differentially connecting these elements, thereby expanding the gear ratio range while maintaining structural simplicity of each individual element.
Solution Approach 2:
Each rotating element in the planetary gear device is designed to serve multiple functions. The same set of rotating elements can be connected to input and output shafts in different configurations to achieve various gear ratios, making the device universal and adaptable to different transmission requirements without increasing the number of basic components.
2Device complexity
If a normal type of planetary gear device with three rotating elements is employed, then the structure is simple, but the radial dimension and weight of the entire torque converter apparatus are increased
Solution Approach 1:
The planetary gear device merges multiple rotating elements into a compact integrated structure where the sun gear, ring gear, and carrier share common mounting spaces and support structures. By combining these elements in a nested arrangement, the radial dimension and overall weight of the torque converter apparatus are reduced compared to having separate gear mechanisms.
Solution Approach 2:
The planetary gear elements are arranged in a nested configuration where the sun gear is positioned at the center, planetary gears orbit around it, and the ring gear encloses the entire planetary gear set. This nesting allows multiple rotating elements to occupy overlapping radial spaces, minimizing the overall radial footprint and weight of the apparatus.
3Device complexity
If the number of rotating elements is limited to three, then the structure is simple, but the selectable range of damper mass and damper spring is narrow
Solution Approach 1:
The planetary gear device incorporates a dynamic connection system where rotating elements can be selectively engaged or disengaged from input and output shafts based on operating conditions. This dynamic reconfigurability allows the damper mass and damper spring parameters to be adjusted by changing which rotating elements are connected, providing a wide selectable range without increasing the number of physical damper components.
Solution Approach 2:
The device enables parameter changes in the damper system by varying the connection configuration of rotating elements. By changing which rotating elements are connected to input and output shafts, the effective gear ratio and damper characteristics can be adjusted, providing adaptability in damper mass and spring parameters without adding more rotating elements.
4Quantity of substance
If additional members of larger weight are connected to the rotating element functioning as damper mass, then the desired damper mass value can be obtained, but the energy loss in power transmission increases and acceleration performance is reduced
Solution Approach 1:
The planetary gear device pre-configures the damper mass by integrating it with the rotating elements that are already part of the power transmission path. The damper mass is formed by selected rotating elements (such as the carrier or ring gear) that would otherwise be necessary for gear operation, eliminating the need for additional separate mass components and reducing energy loss.
Solution Approach 2:
The rotating elements in the planetary gear device serve dual purposes: they perform gear transmission functions and simultaneously provide the damper mass. Each rotating element (sun gear, ring gear, carrier) contributes to both power transmission and damping, making the system self-sufficient and eliminating the need for additional dedicated mass components that would increase energy loss.
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 enables a broader selection of gear ratios and improved space efficiency, reducing energy loss and interference, thereby enhancing the vehicle's acceleration performance and accommodating limited vehicle body spaces effectively.
Implementation Method 1
resilient members for connecting, each other, two rotating elements selected from at least two rotating gear elements and the carrier elements. The resilient members are for making the selected two elements to participate a power transmission
Data Source
AI summary
The present invention relates to a dynamic damper provided with a planetary dear device and damper springs and aims to obtain an increased adjustable range of gear ratio for obtaining a desired reduction of rotating fluctuation and to reduce a size in a radial direction. A plurality of planetary gears 34 are provided, each forms a stepped shape (Ravigneau type planetary gear device) and is constructed by a small diameter pinion 42 and a large diameter pinion 44 juxtaposed in an axial direction so as to be rotated integrally. Rotating elements, which are selectively and desirably arranged to mesh with the small diameter pinion 42 and the large diameter pinion 44, are large diameter and small diameter ring gears and large diameter and small diameter sun gears. In addition to a carrier connecting the plurality of stepped shaped planetary gears 34, two rotating elements are selected from the large diameter and small diameter ring gears and the large diameter and small diameter sun gears. Among the selected elements, two selected rotating elements, for example, the large diameter sun gear and the carrier are assigned to the inlet and the outlet elements, respectively and the remaining small sun gear 40 is assigned to the mass element.