Split Transmission Planetary Gear Torque Path

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing group transmission devices for commercial vehicles with rear-mounted claw designs face challenges in shifting between gear groups without load interruption, requiring significant effort and limiting power shiftability.

Innovation Solution

The group transmission device incorporates a second planetary gear set with its first transmission element coupled to the countershaft, allowing torque transmission from the second planetary gear set to the countershaft, and the countershaft connected to the third transmission element of the first planetary gear set, enabling torque introduction from the countershaft into the first planetary gear set, facilitated by additional switching units for seamless gear shifting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If traditional group transmission devices are used, then structural simplicity is maintained, but power shiftability between gear groups is limited

Engineering Contradiction:
Improvetransmission structureVSAvoidpower shiftability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The invention merges two planetary gear sets (first and second planetary gear sets) into a single transmission device with shared components. The countershaft acts as a common connection point that integrates both gear groups, allowing them to function as a unified system with enhanced power shiftability while avoiding the need for completely separate transmission units.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The countershaft serves multiple functions: it supports the second planetary gear set, connects to the first planetary gear set, and enables power transfer between gear groups. This multi-functional element allows the transmission to achieve versatile power shifting capabilities without proportionally increasing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If gear shifting is performed under load, then continuous power transmission is maintained, but mechanical wear increases

Engineering Contradiction:
Improvecontinuous power transmissionVSAvoidmechanical wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The dual planetary gear set configuration with countershaft connection enables continuous power transmission during gear group transitions. While one gear group is disengaging, the other can be engaged through the countershaft path, ensuring that power flow never中断 and eliminating the need to stop or reduce engine power during shifts.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The switching units are designed to pre-position and pre-engage the appropriate gear elements before the actual shift occurs. The countershaft connection allows preliminary engagement of the second planetary gear set while the first is still carrying load, so that when the transition occurs, the new path is already ready to immediately承接 the power flow without sudden shocks or excessive wear.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3669101B1Range-change transmission device
Publication Date: 2021.10.20 DAIMLER TRUCK AG
  • EP3669101B1 patent drawingFigure 1
  • EP3669101B1 patent drawingFigure 2
  • EP3669101B1 patent drawingFigure 3

AI summary

The invention relates to a range-change transmission device (10), in particular a split transmission, having an input shaft (12), an intermediate shaft (14), a countershaft (16), a transmission output shaft (18) and a first planetary gear set (P1). A first transmission element (P11) of the first planetary gear set (P1) is permanently coupled to the intermediate shaft (14) for conjoint rotation, a second transmission element (P12) of the first planetary gear set (P1) is coupled to the transmission output shaft (18), a first shift unit (S1) is provided, in at least one shift position (S12), to arrange a third transmission element (P13) of the first planetary gear set (P1) in a manner fixed in relation to the housing, the range-change transmission device (10) comprises a second planetary gear set (P2), and a third transmission element (P23) of the second planetary gear set (P2) is permanently coupled to the intermediate shaft (14) for conjoint rotation.