Lockup Control Valve Nesting in Power Transmission Device
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing power transmission devices for vehicles suffer from high pressure losses and increased size due to complex oil passage configurations in the lockup device, leading to reduced responsiveness of the clutch and a larger overall device footprint.
Innovation Solution
A power transmission device with a lockup control valve positioned on the outer side surface of the casing, recessed towards the shaft, and a linear casing side oil passage that connects the lockup control valve directly to the transmission shaft side oil passage, reducing pressure losses and enhancing clutch responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oil passage is configured with a combination of axial holes and radial holes, then the lockup device can be assembled, but the oil passage becomes bent and complex, causing large pressure losses and reduced clutch responsiveness
Solution Approach 1:
The oil passage is segmented into three distinct parts: a first oil passage in the casing, a second oil passage in the transmission shaft, and a third oil passage in the rotating body. This segmentation allows each passage to be optimized independently, with the first passage being linear to minimize pressure losses while the other passages are positioned in their respective components. The segmentation resolves the contradiction by eliminating the need for a complex bent oil passage while maintaining proper oil delivery to the lockup clutch.
2Reliability
If the control valve is mounted on the outer side face of the casing, then the lockup device can be assembled, but the projecting amount of the control valve becomes large, resulting in a large-sized power transmission device
Solution Approach 1:
The control valve is nested within a recess formed in the outer side face of the casing, rather than projecting outward. The recess accommodates the control valve body, allowing it to be positioned inside the casing's boundary. This nesting approach reduces the projecting amount of the control valve to minimal or zero, thereby miniaturizing the overall power transmission device while maintaining the lockup device's functionality.
3Reliability
If the oil passage is configured with multiple axial and radial holes, then the lockup clutch can be supplied with pressurized oil, but the bent oil passage configuration causes large pressure losses
Solution Approach 1:
The oil passage is segmented into three distinct parts: a first oil passage in the casing, a second oil passage in the transmission shaft, and a third oil passage in the rotating body. This segmentation allows each passage to be optimized independently, with the first passage being linear to minimize pressure losses while the other passages are positioned in their respective components. The segmentation resolves the contradiction by eliminating the need for a complex bent oil passage while maintaining proper oil delivery to the lockup clutch.
Solution Approach 2:
Instead of forming a single bent oil passage that curves through the casing, the invention inverts the approach by creating a linear first oil passage in the casing that connects to separate oil passages in the transmission shaft and rotating body. This inversion from a curved path to a straight path minimizes pressure losses while achieving the same oil delivery function.
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 minimizes pressure losses, increases clutch responsiveness, and allows for a more compact device design by reducing the projecting amount of the control valve and optimizing oil passage flow, thereby enhancing the reliability and miniaturization of the power transmission device.
Implementation Method 1
a torque converter that is mounted in the casing to transmit the rotation of the engine through fluid to the transmission
Implementation Method 2
a lockup clutch for establishing connection between the rotating body and the transmission shaft by pressurized oil delivered from a hydraulic pump
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A lockup device (63) includes a lockup clutch (64) for establishing connection between a rotating body (44) of a torque converter (41) and a transmission shaft (55), a lockup control valve (70) that controls supply/discharge of pressurized oil from a hydraulic pump (69) to/from the lockup clutch (64), and a lockup oil passage (75) that introduces pressurized oil from the lockup control valve (70) to the lockup clutch (64). The lockup control valve (70) is arranged on an outer side face (18B) of an intermediate casing (18) in a position of radially overlapping the transmission shaft (55) in a radial direction of the transmission shaft (55). Further, a casing side oil passage (76) constituting the lockup oil passage (75) is formed as a linear oil passage that linearly extends in the radial direction of the transmission shaft (55) between the lockup control valve (70) and the transmission shaft side oil passage (77).