Primary Transmission Casing Layout for Lower Gear Stirring Loss

Solution Overview

Problem

The existing working vehicles suffer from high gear stirring resistance in the primary transmission casing due to the complete filling of fluid, leading to horsepower loss.

Innovation Solution

The primary transmission casing is separated from the hydraulic transmission chamber, with a controlled communication through an orifice and an outflow passage to manage fluid flow, maintaining a reduced fluid level and reducing gear stirring resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the primary transmission casing is completely filled with fluid to ensure proper lubrication and cooling, then the lubrication effect is improved, but the gear stirring resistance increases causing horsepower loss

Engineering Contradiction:

Improvelubrication effectVSAvoidhorsepower loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The transmission system is divided into two separate casings: the primary transmission casing containing gears and the hydraulic transmission chamber containing the hydraulic pump and motor. This segmentation allows each component to operate in its optimal fluid environment without compromising the other, resolving the contradiction between adequate lubrication and reduced gear stirring resistance

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hydraulic transmission chamber is extracted as a separate enclosed space from the primary transmission casing. By taking out the hydraulic components and their fluid environment, the primary transmission casing can maintain reduced fluid levels without compromising the hydraulic system's functionality, thereby reducing gear stirring resistance while maintaining proper lubrication

Inventive Principle:

Principle #2Taking out (Extraction)

2Temperature

If the primary transmission casing is completely filled with fluid to ensure adequate cooling, then the cooling effect is improved, but the gear stirring resistance increases causing energy loss

Engineering Contradiction:

Improvecooling effectVSAvoidenergy loss

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The transmission system is divided into two separate casings: the primary transmission casing containing gears and the hydraulic transmission chamber containing the hydraulic pump and motor. This segmentation allows each component to operate in its optimal fluid environment without compromising the other, resolving the contradiction between adequate lubrication and reduced gear stirring resistance

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The hydraulic transmission chamber is extracted as a separate enclosed space from the primary transmission casing. By taking out the hydraulic components and their fluid environment, the primary transmission casing can maintain reduced fluid levels without compromising the hydraulic system's functionality, thereby reducing gear stirring resistance while maintaining proper lubrication

Inventive Principle:

Principle #2Taking out (Extraction)

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 reduces gear stirring resistance and horsepower loss by optimizing fluid flow and level within the primary transmission casing.

Implementation Method 1

an orifice to allow the hydraulic transmission chamber and the interior of the primary transmission casing to communicate with each other

Methodology Applied

Scientific EffectFluid flow control through orifice:

Implementation Method 2

a supply pump to replenish the hydraulic transmission chamber with purged fluid

Methodology Applied

Scientific EffectHydraulic pump fluid delivery: Pump

Implementation Method 3

an outflow passage to cause fluid inside the primary transmission casing to flow out

Methodology Applied

Scientific EffectFluid outflow through passage:

Data Source

PatentUS20250207659A1Working vehicle

Publication Date: 2025.06.26 KUBOTA CORP

AI summary

A working vehicle includes a hydraulic transmission chamber to accommodate a hydraulic pump and a hydraulic motor driven by fluid delivered from the hydraulic pump, and a primary transmission casing to accommodate a primary transmission that includes an input gear to receive power from a prime mover and a transmission gear to transmit the power transmitted from the input gear to the hydraulic pump. The primary transmission casing is adjacent to the hydraulic transmission chamber. An interior of the primary transmission casing is separated from the hydraulic transmission chamber.