Hybrid Drive Selector Sleeve Layout for Low-Drag High-Speed Operation
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Solution Overview
Problem
Existing hybrid drive systems for motor vehicles are limited by maximum speed, generate high drag losses at high speeds, and are unsuitable for more powerful engines or higher vehicle classes, with electric motors being inefficiently coupled to internal combustion engines and having axial arrangements that are problematic in certain vehicle designs.
Innovation Solution
A switching device with centrally arranged shafts and sliding sleeves that allow independent gear ratio selection for electric motors, enabling efficient operation modes and reducing drag losses by decoupling the second electric motor at higher speeds, and featuring a separate gear stage for optimized coordination between the internal combustion engine and generator electric motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If electric motors are coupled to internal combustion engine with fixed gear ratio, then engine-motor coordination is simplified, but series operation efficiency deteriorates and adaptability to different driving conditions is limited
Solution Approach 1:
The patent implements a dynamic switching device with multiple displacement positions that allow the gear ratio between electric motors and internal combustion engine to be changed during operation. The switching device can connect different gears (first gear, second gear, third gear) to the internal combustion engine output shaft, enabling adaptation to various driving conditions and operation modes including series hybrid mode, parallel hybrid mode, and electric-only mode.
Solution Approach 2:
The transmission system is segmented into multiple independent gears (first gear, second gear, third gear) that can be selectively engaged through the switching device. Each gear provides a different gear ratio, allowing the system to optimize performance for different operating conditions. The switching device segments the power flow paths, enabling flexible configuration of engine-motor connections.
2Power
If both electric motors rotate at top speed during internal combustion engine primary drive, then power transmission is maintained, but drag losses increase significantly
Solution Approach 1:
The switching device enables dynamic decoupling of electric motors from the internal combustion engine during certain operating conditions. When the internal combustion engine provides primary drive, the switching device can disconnect the electric motors from the power flow path, allowing them to rotate at lower speeds or remain stationary, thereby reducing drag losses while maintaining power transmission capability when needed.
Solution Approach 2:
The switching device extracts the electric motors from the mandatory power flow path during internal combustion engine primary drive operations. By providing a direct connection between the internal combustion engine and the final drive that bypasses the electric motors, the system eliminates unnecessary drag losses while preserving the ability to engage electric motors when additional power is required.
3Volume of moving object
If electric motors are arranged axially in series, then space utilization in certain directions is optimized, but compatibility with front-transverse engine configuration and small vehicles deteriorates
Solution Approach 1:
The patent transitions from an axial series arrangement of electric motors to a radial arrangement where the first electric motor and second electric motor are positioned radially offset from each other around the internal combustion engine output shaft. This dimensional change from axial to radial configuration improves compatibility with front-transverse engine layouts and compact vehicle platforms while maintaining efficient space utilization.
Solution Approach 2:
The switching device employs asymmetric positioning of the first and second electric motors at different radial locations, allowing flexible routing of power flow paths. The first sliding sleeve and second sliding sleeve are positioned at different angular locations, enabling independent control of each motor's engagement with the internal combustion engine and final drive, thereby accommodating various vehicle platform requirements.
4Speed
If maximum vehicle speed is increased, then top speed performance is improved, but electric motor efficiency deteriorates due to high-speed operation
Solution Approach 1:
The switching device provides dynamic speed management by enabling the electric motors to operate at optimal speeds across different vehicle speed ranges. Through multiple displacement positions, the system can maintain electric motors at lower speeds during high-vehicle-speed cruise conditions while still achieving high top speeds through the internal combustion engine's direct power transmission path, thereby reducing electric motor drag losses.
Solution Approach 2:
The patent changes the operational parameters of the electric motors by providing different gear ratios through the switching device. By selecting appropriate gear ratios based on vehicle speed and power demands, the electric motors can operate in high-efficiency regions even when the vehicle is traveling at high speeds, thus reducing energy losses while maintaining top speed capability.
Data Source
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AI summary
The invention relates to a selector device (14) for a hybrid drive system (1) of a motor vehicle (2), comprising a centrally arranged shaft (15), a first gear wheel (16) rotatably mounted relative to the shaft (15), and a second gear wheel (17) which is rotatably mounted relative to the shaft (15) and offset along the shaft (15) relative to the first gear wheel (16), each gear wheel (16, 17) being associated with a sliding sleeve (31, 32), which sliding sleeves (31, 32) are designed in such a way that, in a first sliding position, they rotationally fix the shaft (15) to the first gear wheel (16), while the second gear wheel (17) is rotationally decoupled from the shaft (15), in a second sliding position, they rotationally connect the shaft (15) to both the first gear wheel (16) and the second gear wheel (17), in a third sliding position, they rotationally connect the two gear wheels (16, 17) to one another, while the shaft (15) is rotationally decoupled from the two gear wheels (16, 17), and in a fourth sliding position, they rotationally decouple the two gear wheels (16, 17) from each other and the shaft (15) from the two gear wheels (16, 17). The invention also relates to a drive system (1) having this selector device (14), and to a motor vehicle (1) including this drive system (1).