Vehicle Drive Oil Passage Structure Without a Mechanical Oil Pump
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Solution Overview
Problem
The inefficiency in vehicle drive devices due to the loss caused by driving an oil pump using a mechanical power transmission path leads to decreased drive efficiency.
Innovation Solution
A vehicle drive device design that includes a housing chamber with a power transmission mechanism and an oil passage structure, utilizing a rotary shaft member and a rotating body to scrape up oil and supply it to a shaft bearing without an oil pump driven by a power transmission path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If an oil pump driven by a power transmission path is used to supply oil, then oil supply is achieved, but drive efficiency decreases due to mechanical losses
Solution Approach 1:
The patent extracts the oil pump from the power transmission path, eliminating the need for a mechanically driven oil pump. Instead, oil is supplied to the shaft bearing through a scraping mechanism that utilizes the rotational motion of the rotor shaft itself, thereby removing the source of mechanical losses associated with dedicated oil pump operation
Solution Approach 2:
The rotor shaft serves multiple functions: it transmits power and simultaneously acts as a scraping mechanism for oil supply. The rotating body attached to the rotor shaft performs both the scraping function and facilitates oil delivery to the bearing, eliminating the need for a separate oil pump component
2Loss of energy
If oil is scraped up by a rotating body in the second housing chamber, then oil can be supplied without a power transmission driven pump, but oil must be transported axially across housing chambers
Solution Approach 1:
The oil passage structure is nested within the partition wall that separates the two housing chambers. The first through hole is formed directly in the partition wall, and the oil passage portion is integrated into the partition wall structure, allowing compact axial oil transport without requiring external or lengthy oil supply paths
Solution Approach 2:
The partition wall serves as an intermediary structure that facilitates oil transport between the two housing chambers. By forming the through hole and oil passage directly in the partition wall, it acts as a built-in conduit that efficiently bridges the axial gap between chambers without requiring additional external piping or mechanisms
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
Enables efficient oil supply to a side farther from the scraping side in the axial direction without using an oil pump, enhancing drive efficiency by eliminating mechanical losses.
Implementation Method 1
a rotating body that is disposed in the second housing chamber, rotates in conjunction with the rotary shaft member, and is configured to scrap up oil accumulated in a lower portion of the housing chamber
Implementation Method 2
supplies oil scraped up by the rotating body in the second housing chamber to the shaft bearing via the first through hole and the oil passage portion
Implementation Method 3
an oil passage structure, at least a part of which is formed in the case. The power transmission mechanism includes a rotary shaft member that is disposed in the first housing chamber, extends in the axial direction, and rotates about an axis during power transmission
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
Disclosed is a vehicle drive device including: a case; a power transmission mechanism capable of transmitting power from a power source to wheels; and an oil passage structure. The power transmission mechanism includes a rotary shaft member that is disposed in a first housing chamber of the case, extends in an axial direction, and rotates about an axis during power transmission, and a rotating body that is disposed in a second housing chamber of the case, rotates in conjunction with the rotary shaft member, and is capable of scraping up oil accumulated in a lower portion of the housing chamber. The axial end of the rotary shaft member on a side farther from a partition wall portion in the axial direction is supported by the case via a shaft bearing. The oil passage structure includes an axially first through hole formed in the partition wall portion and an oil passage portion extending in the axial direction in the first housing chamber, and supplies oil scraped up by the rotating body in the second housing chamber to the shaft bearing via the first through hole and the oil passage portion.