Multi-stage Planetary Gear Train Coupling Mechanism
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Solution Overview
Problem
Existing multi-stage planetary gears face challenges in miniaturization due to the need for large screws for force absorption and lack of precision in component alignment, especially when using plastic ring gear segments, which are difficult to fasten securely.
Innovation Solution
The multi-stage planetary gear employs a coupling mechanism where ring segments are connected via tapered sleeves with slots and complementary bores, using dowel pins for precise locking, replacing traditional screw connections with a clamp-like system that allows for precise alignment and secure attachment without deforming the gear geometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional screw connections are used to join ring segments, then force absorption is achieved, but the structure cannot be miniaturized and precision alignment is lost
Solution Approach 1:
The coupling area is divided into multiple coupling zones with individual coupling elements (protrusions and recesses) distributed around the circumference. This segmentation allows precise alignment through multiple localized contact points while maintaining a compact overall structure.
Solution Approach 2:
The coupling elements act as intermediary features between adjacent ring segments, providing precise alignment through their geometric relationship (protrusions fitting into recesses) without requiring large fastening elements.
2Strength
If large screws are used for force absorption in ring segments, then connection strength is achieved, but miniaturization becomes difficult
Solution Approach 1:
The connection strength is achieved through multiple distributed coupling elements rather than a single large screw. The cumulative effect of several smaller coupling features provides sufficient force absorption while maintaining a compact structure.
Solution Approach 2:
The coupling elements serve dual functions: they provide precise alignment through their geometric fit and simultaneously absorb forces through their distributed arrangement. This merging of alignment and force-absorption functions eliminates the need for separate large fastening elements.
3Ease of manufacture
If screw fastening is used in plastic ring gear segments, then connection is achieved, but load-bearing capacity is insufficient for small diameters
Solution Approach 1:
Instead of inserting fastening elements into the plastic material (which has limited load-bearing capacity), the design uses integral coupling features that are part of the plastic structure itself. The protrusions and recesses are formed as integral features of the ring segments, distributing loads across the entire coupling area rather than concentrating them in small threaded bores.
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 solution enables significant miniaturization, higher precision, and reduced manufacturing costs by ensuring precise alignment and secure attachment of ring segments, overcoming the limitations of traditional screw connections in plastic gear construction.
Implementation Method 1
the locking element of a segment is positively locked in the radial direction and non-positively locked in the axial direction in the receiving element of an adjacent segment or in an adapter plate
Data Source
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AI summary
The invention relates to a multi-stage planetary gear train (1), comprising several annular segments (2) arranged one behind the other in the axial direction between the adapter plates (13) of the motor (11) and of the gear head (12), each annular segment having a planetary gear set comprising a sun gear, several planet gears carried by a planet carrier, and a ring gear having inner teeth, wherein adjacent annular segments (2) are coupled to each other and the outer segments (2) are coupled to the respective adapter plates (13). The invention is characterized in that the annular segments (2) and the corresponding adapter plates (13) in the region of the adjacent end faces (3) thereof form a coupling area (4) each, and the segments (3) each comprise at least one engaging element (5) on one end face (3) thereof and at least one complementary receiving element (6) on the opposite end face (3) thereof, wherein the engaging element (5) of a segment (3) engage in the receiving element (6) of an adjacent segment (3) or of an adapter plate (13) in a form-fit or force-closed manner in the assembled state.