Vehicle Drive Device Cylindrical Projection Axial Length Reduction
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Solution Overview
Problem
Existing drive devices for vehicles require additional axial length to facilitate appropriate oil supply to the operating oil pressure chamber and rotational support of the rotor member, leading to increased device size.
Innovation Solution
A drive device design featuring a case with a radially extending support wall and a cylindrical projecting portion that supports the rotor member and supplies oil to the operating oil pressure chamber, reducing the axial length by integrating these functions into a single unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate wall portions are used on both axial sides to supply hydraulic pressure and support the rotor member, then appropriate oil supply and rotational support are achieved, but the axial length increases
Solution Approach 1:
The invention merges the support wall and cylindrical projecting portion into a single integrated structure. The support wall extends radially from the case, and the cylindrical projecting portion projects from the support wall to provide both structural support and oil supply functions, eliminating the need for separate components on both axial sides.
Solution Approach 2:
The cylindrical projecting portion serves multiple functions: it provides rotational support for the rotor member via the support bearing, supplies oil to the operating oil pressure chamber through the operating oil supply passage, and maintains structural integrity. This multi-functional design reduces the number of components and axial length.
2Length of moving object
If the device size is reduced by decreasing axial length, then compactness is improved, but it becomes difficult to accommodate both oil supply passages and rotor support structures
Solution Approach 1:
The invention transitions from a two-dimensional arrangement (separate wall portions on both axial sides) to a three-dimensional integrated structure. The cylindrical projecting portion extends in the axial direction from the support wall, creating a multi-level structure that accommodates multiple functions within a compact axial space.
Solution Approach 2:
The operating oil supply passage is nested within the cylindrical projecting portion. The passage is formed inside the wall thickness of the cylindrical structure, allowing oil supply functionality to be embedded within the structural component itself, thereby saving space and reducing complexity.
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 solution allows for effective oil supply and rotational support of the rotor member while minimizing the axial length of the device, resulting in a more compact and efficient drive system.
Implementation Method 1
a rotor member of the rotary electric machine is radially supported by the cylindrical projecting portion in a rotatable state via a support bearing
Implementation Method 2
the engagement device includes an operating oil pressure chamber supplied with the hydraulic pressure
Data Source
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AI summary
To provide a drive device for a vehicle that can appropriately supply oil to an operating oil pressure chamber of an engagement device and can rotatably support a rotor member of a rotary electric machine appropriately, and that can be downsized as a whole by further reducing an axial length of the device. A drive device for a vehicle includes an input member I drivingly connected to an internal combustion engine, an output member drivingly connected to a wheel, a rotary electric machine MG, a fluid coupling, an engagement device C1, and a case 3 housing these components. The case 3 includes a support wall 5 extending radially on the internal combustion engine side relative to the engagement device C1, and a cylindrical projecting portion 11 projecting from the support wall 5 toward the engagement device C1 side. The engagement device C1 includes an engagement member 33, a pressing member 34, and an operating oil pressure chamber H1. A rotor Ro of the rotary electric machine MG is supported by the cylindrical projecting portion 11 via a support bearing 71, and the cylindrical projecting portion 11 is formed with an operating oil supply passage L1 supplying oil to the operating oil pressure chamber H1.