Drive Unit Locking Element Prevents Gear Skipping
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Solution Overview
Problem
Existing drive units for motor vehicle door locks experience toothed segment skipping and increased wear and noise due to delayed motor stoppage, leading to high forces acting on gear links and subsequent noise emissions.
Innovation Solution
Incorporating a locking element that secures the distance between the axes of rotation in the first stop position, preventing the increase or decrease of this distance, thereby locking the gear members in place and reducing wear and noise emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor is stopped by detecting power consumption, then the drive unit can determine when to stop the motor, but the delayed current consumption change causes the motor to continue running for a few milliseconds, resulting in high forces on gear links and toothed segment skipping
Solution Approach 1:
The locking element is activated before the motor completely stops to preemptively secure the gear members in their final position. By detecting the approach to the stop position and engaging the locking element in advance, the system prevents the harmful effects of delayed motor stoppage, including toothed segment skipping and high forces on gear links.
2Reliability
If the motor continues running for a few milliseconds after reaching the stop position, then the drive unit can ensure complete stopping, but very high forces act on the drive unit and gear links during this time
Solution Approach 1:
The locking element engages before the motor fully stops to preemptively secure the gear members. This preliminary locking action allows the motor to complete its stopping process without transmitting high forces to the gear links, as the locking element absorbs and distributes these forces, preventing damage to the transmission elements.
3Adaptability or versatility
If the distance between axes of rotation is not secured, then the gear members can accommodate manufacturing tolerances and assembly variations, but the toothed segments are prone to skipping and wear increases
Solution Approach 1:
The locking element secures the distance between axes of rotation at the precise moment when the gear members reach their intended engagement position. This preliminary securing action maintains optimal meshing conditions throughout operation, preventing toothed segment skipping and wear while still allowing for manufacturing tolerances and assembly variations during the engagement process.
Data Source
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AI summary
The invention relates to a drive unit (1, 41) for automotive applications, in particular a central locking drive unit for a motor-vehicle door closure, comprising a motor (2, 42) and a transmission unit (3, 43). The transmission unit has at least a first transmission element (4, 44) and a second transmission element (5, 45), which have, respectively, a first tooth segment (6, 46) and a second tooth segment (7, 47) and a first axis of rotation (8, 48) and a second axis of rotation (9, 49). The transmission unit also has a first stop (10, 50). The drive unit has at least a first stop position, and at least the first transmission element (4, 44) has a locking element (11, 51), which is locked in the first stop position by means of an accommodating element (12, 52) and secures a distance (20) of the first axis of rotation (8, 48) of the first transmission element (4, 44) from the second transmission element (5, 45) in the first stop position.