Reduction Gear Unit Oil Layout for Low-Resistance Lubrication
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Solution Overview
Problem
Existing motor units face challenges in efficiently adjusting and maintaining the oil level for cooling and lubrication, leading to increased friction and energy loss, particularly in the rotation of the final gear and rotor core, which affects the efficiency and travel distance of electric vehicles.
Innovation Solution
The motor unit incorporates a housing with catch tanks CT1 to CT5 that overlap the final gear and motor, allowing for efficient collection and redistribution of oil, reducing friction by adjusting the oil level and promoting lubrication design options, and includes a communication tunnel to maintain consistent oil levels between the motor and gear chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oil level in the gear case is increased to improve lubrication, then the lubrication effect is enhanced, but the friction and energy loss increase due to oil resistance
Solution Approach 1:
The gear case is divided into an upper gear case and a lower gear case, with the final gear spanning both sections. The oil level is controlled to be below the rotation axis of the final gear in the lower gear case, ensuring lubrication of the meshing portion while minimizing oil resistance during rotation.
Solution Approach 2:
The oil level is strategically positioned to provide localized lubrication exactly where needed (at the meshing portion of the final gear) without submerging the entire gear structure, thus achieving effective lubrication with minimal energy loss from oil resistance.
2Loss of energy
If the oil level is adjusted to reduce friction, then energy loss decreases, but the lubrication effect may be insufficient
Solution Approach 1:
The gear case is segmented into upper and lower sections, allowing independent oil level control. The oil level in the lower gear case is specifically maintained below the rotation axis, ensuring the meshing portion remains lubricated while the gear body operates with minimal oil resistance.
Solution Approach 2:
The oil level is pre-adjusted to an optimal position before operation, ensuring that the meshing portion of the final gear is adequately lubricated while preventing excessive oil from causing increased friction and energy loss during rotation.
3Ease of operation
If a separate oil adjustment mechanism is added to control oil levels, then oil level control is improved, but the device complexity increases
Solution Approach 1:
The gear case is divided into upper and lower sections with a communication tunnel between them, allowing oil to flow freely while enabling simple level control. This segmentation eliminates the need for complex adjustment mechanisms while maintaining effective oil level management.
Solution Approach 2:
The communication tunnel between the upper and lower gear cases allows oil to automatically equalize and flow between sections based on gravity and pressure differences, eliminating the need for active pumps or complex control systems while maintaining proper oil distribution.
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 the oil level in the gear chamber, decreases friction, and enhances lubrication, thereby improving the electricity cost and travel distance of electric vehicles by efficiently managing oil distribution and reducing rotational resistance.
Implementation Method 1
the opening is positioned below a horizontal plane passing through an axis of the gear and orthogonal to a gravity direction
Data Source
AI summary
Provided is a unit including: a motor case configured to accommodate a motor, a gear case configured to accommodate a gear connected to the motor; and a cover having a portion sandwiched between the gear and the motor, in which the motor case communicates with the gear case via an opening of the cover, and the opening is positioned below a horizontal plane passing through an axis of the gear and orthogonal to a gravity direction.