Power Splitting Transmission Countershaft Layout
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power branching transmission devices for working machines, such as wheel loaders, face design complexity and increased space requirements due to the arrangement of shifting elements on hydrostatic shafts, leading to vibration issues and inefficient use of space.
Innovation Solution
The transmission device incorporates shifting elements on separate countershafts, allowing for a hydrostatic and mechanical power branching system with reduced space requirements, utilizing a planetary gear system for efficient torque summation and minimizing axial space usage, while reducing wobbling tendencies and drag torques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If shifting elements are arranged on hydrostatic shafts, then power branching transmission can be achieved, but design complexity increases due to vibration damping requirements and articulated connection needs
Solution Approach 1:
The transmission system is divided into separate functional modules: hydrostatic shafts for power transmission and separate countershafts for shifting element arrangement. This segmentation allows each component to perform its specific function without compromising design simplicity or vibration damping performance.
Solution Approach 2:
Countershafts are introduced as intermediary elements that carry the shifting elements separately from the hydrostatic shafts. This intermediary structure enables gearshift operations without directly coupling shifting mechanisms to the hydrostatic power transmission path, thereby avoiding vibration-related design complications.
2Adaptability or versatility
If shifting elements are arranged on hydrostatic shafts, then power branching transmission can be achieved, but axial space requirement increases due to distance between hydrostatic shafts
Solution Approach 1:
The shifting elements are relocated from the radial/hydrostatic shaft arrangement to axial countershafts. This dimensional reorganization allows the transmission device to occupy less axial space while maintaining all necessary power branching and gearshift functions.
3Object-affected harmful factors
If hydrostatic device is mounted by elastic rubber mount for vibration damping, then vibration reduction is achieved, but axial offset variation during operation requires articulated connection design
Solution Approach 1:
The system separates vibration-sensitive hydrostatic connections from shifting operations by placing shifting elements on independent countershafts. This segmentation eliminates the need for articulated connections while preserving vibration damping through elastic mounts.
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 design results in a more compact, efficient transmission device with reduced vibration and space usage, enabling multiple driving ranges with lower design complexity and improved modularity for various applications.
Implementation Method 1
a planetary gear system is provided, which comprises two sun gears that mesh with common double planetary gears which, in turn, mesh with a ring gear
Implementation Method 2
part of an applied torque can be transmitted in a first power branch at least by way of a hydrostatic device with at least two hydrostatic shafts
Data Source
AI summary
A transmission with power branching, and the transmission, in a first drive range, transmits torque from the ring gear to a fixed wheel. In one branch, power is transmitted from a first to a second hydraulic unit which respectively operate as a pump and a motor. At one of the hydrostatic shafts, the mechanical and hydrostatic power are summed and transmitted to the drive output. In a second drive range, power coming from the planetary carrier is partially branched off to the ring gear and transmitted, via the gear wheels of the hydrostatic shaft, to the second hydraulic unit. From the second hydraulic unit, hydraulic power passes to the first hydraulic unit. In the process, the first hydraulic unit operates as a motor and the second hydraulic unit as a pump. From the second sun gear, power is transmitted to the double planetary gear and summed.