Power Transmission Apparatus Vertical Component Positioning

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Solution Overview

Problem

Existing power transmission apparatuses in vehicles lack sufficient cooling and lubrication, leading to inefficiencies and increased rotational resistance in the transmission of power.

Innovation Solution

A power transmission apparatus is designed with a rotating electric device, a speed reducer lubricated by oil, and a case configuration that positions the stator and rotor to facilitate cooling and minimize oil interference, while using a differential device connected to axle shafts and reservoir tanks to manage oil distribution and reduce rotational resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the speed reducer is lubricated by oil, then the lubrication effect is improved, but the rotational resistance of the rotor increases due to oil interference

Engineering Contradiction:
Improvelubrication effectVSAvoidrotational resistance
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent positions components in the vertical dimension (height direction) to create spatial separation. The stator is positioned lower than the rotor, and the oil level is controlled to be between them, using vertical positioning to resolve the conflict between lubrication and rotational resistance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Different parts of the system are given different oil contact conditions. The speed reducer gears are positioned to contact oil for lubrication, while the rotor is positioned above the oil level to avoid oil interference, creating localized quality differences in oil exposure.

Inventive Principle:
Principle #3Local quality

2Temperature

If the rotor is positioned lower to improve cooling, then the cooling effect is improved, but the oil interference with rotor rotation increases

Engineering Contradiction:
Improvecooling effectVSAvoidrotational resistance
Core Design Contradiction:
TemperatureVSForce

Solution Approach 1:

The patent uses vertical positioning in the height direction to simultaneously achieve cooling and reduce rotational resistance. The stator is positioned lowest for cooling, the rotor is positioned higher to avoid oil interference, creating a vertical arrangement that resolves both requirements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The oil level acts as an intermediary element positioned between the stator and rotor. It provides cooling to the stator while being kept below the rotor level to minimize interference with rotor rotation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the first driven gear is positioned lower to increase oil contact, then the lubrication effect is improved, but the rotational resistance of the first drive gear increases

Engineering Contradiction:
Improvelubrication effectVSAvoidrotational resistance
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent creates localized quality differences in oil exposure. The first driven gear (low-speed) is positioned to contact oil for lubrication, while the first drive gear (high-speed) is positioned to minimize oil contact, matching oil exposure to the specific needs of each component.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the operational parameters by positioning gears at different heights. The first driven gear operates with high oil contact for lubrication, while the first drive gear operates with reduced oil contact to minimize rotational resistance, optimizing parameters for each component's function.

Inventive Principle:
Principle #35Parameter changes

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

The apparatus effectively cools the stator and reduces rotational resistance by optimizing the position of components and oil distribution, enhancing the efficiency of power transmission and reducing wear on components.

Implementation Method 1

a speed reducer that reduces a speed of rotation output from the rotating electric device, and that is lubricated by oil

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

a reservoir tank in which the oil, which is scooped up by at least one of the first driven gear and the second driven gear, is stored

Methodology Applied
Scientific EffectFluid distribution:

Data Source

PatentEP2159092B1Power transmission apparatus
Publication Date: 2012.09.19 TOYOTA JIDOSHA KK
  • EP2159092B1 patent drawingFigure 1
  • EP2159092B1 patent drawingFigure 2~3
  • EP2159092B1 patent drawingFigure 4~5

AI summary

A power transmission apparatus includes a rotating electric device (2200) including a rotor (2231) and a stator (2232); a speed reducer; and a case. The speed reducer includes a first drive gear provided on a first shaft connected to the rotating electric device (2200); a first driven gear (1042) that engages with the first drive gear, and that is provided on a second shaft that is parallel to the first shaft; a second drive gear provided on the second shaft; and a second driven gear (1044) that engages with the second drive gear, and that rotates coaxially with the first shaft. The lower end (2232b) of the stator (2232), the lower end (1044b) of the second driven gear (1044), the lower end (1042b) of the first driven gear (1042), and the lower end (2231b) of the rotor (2231) are disposed in a stated order in a direction from a lower position to an upper position, in the case.